| 1. |
- Wirestam, Lina, 1986-, et al.
(författare)
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Osteopontin and disease activity in patients with recent-onset systemic Lupus Erythematosus : Results from the SLICC Inception Cohort
- 2019
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Ingår i: Journal of Rheumatology. - : The Journal of Rheumatology. - 0315-162X .- 1499-2752. ; 46:5, s. 492-500
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Tidskriftsartikel (refereegranskat)abstract
- Objective. In cross-sectional studies, elevated osteopontin (OPN) levels have been proposed to reflect, and/or precede, progressive organ damage and disease severity in systemic lupus erythematosus (SLE). We aimed, in a cohort of patients with recent-onset SLE, to determine whether raised serum OPN levels precede damage and/or are associated with disease activity or certain disease phenotypes. Methods. We included 344 patients from the Systemic Lupus International Collaborating Clinics (SLICC) Inception Cohort who had 5 years of followup data available. All patients fulfilled the 1997 American College of Rheumatology (ACR) criteria. Baseline sera from patients and from age- and sex-matched population-based controls were analyzed for OPN using ELISA. Disease activity and damage were assessed at each annual followup visit using the SLE Disease Activity Index 2000 (SLEDAI-2K) and the SLICC/ACR damage index (SDI), respectively. Results. Compared to controls, baseline OPN was raised 4-fold in SLE cases (p < 0.0001). After relevant adjustments in a binary logistic regression model, OPN levels failed to significantly predict global damage accrual defined as SDI ≥ 1 at 5 years. However, baseline OPN correlated with SLEDAI-2K at enrollment into the cohort (r = 0.27, p < 0.0001), and patients with high disease activity (SLEDAI-2K ≥ 5) had raised serum OPN (p < 0.0001). In addition, higher OPN levels were found in patients with persistent disease activity (p = 0.0006), in cases with renal involvement (p < 0.0001) and impaired estimated glomerular filtration rate (p = 0.01). Conclusion. The performance of OPN to predict development of organ damage was not impressive. However, OPN associated significantly with lupus nephritis and with raised disease activity at enrollment, as well as over time.
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| 2. |
- Ambrosi, Aurelie, et al.
(författare)
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Development of heart block in children of SSA/SSB-autoantibody-positive women is associated with maternal age and displays a season-of-birth pattern
- 2012
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Ingår i: Annals of the Rheumatic Diseases. - London : BMJ Publishing Group. - 0003-4967 .- 1468-2060. ; 71:3, s. 334-340
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Tidskriftsartikel (refereegranskat)abstract
- Objective Congenital heart block may develop in the fetuses of Ro/SSA-positive and La/SSB-positive mothers. Recurrence rates of only 10-20% despite persisting maternal antibodies indicate that additional factors are critical for the establishment of heart block. The authors investigated the influence of other maternal and fetal factors on heart block development in a Swedish population-based cohort. less thanbrgreater than less thanbrgreater thanMethods The influence of fetal gender, maternal age, parity and time of birth on heart block development was analysed in 145 families, including Ro/La-positive (n=190) and Ro/La-negative (n=165) pregnancies. less thanbrgreater than less thanbrgreater thanResults There was a recurrence rate of 12.1% in Ro/La-positive women, and no recurrence in Ro/La-negative women. Fetal gender and parity did not influence the development of heart block in either group. Maternal age in Ro/La-positive pregnancies with a child affected by heart block was, however, significantly higher than in pregnancies resulting in babies without heart block (pandlt;0.05). Seasonal timing of pregnancy influenced the outcome. Gestational susceptibility weeks 18-24 occurring during January-March correlated with a higher proportion of children with heart block and lower vitamin D levels during the same period in a representative sample of Swedish women and a corresponding higher proportion of children with heart block born in the summer (pandlt;0.02). Maternal age or seasonal timing of pregnancy did not affect the outcome in Ro/La-negative pregnancies. less thanbrgreater than less thanbrgreater thanConclusion This study identifies maternal age and seasonal timing of pregnancy as novel risk factors for heart block development in children of Ro/La-positive women. These observations may be useful for counselling when pregnancy is considered.
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| 3. |
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| 4. |
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| 5. |
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| 6. |
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| 7. |
- Arnander, Claes, et al.
(författare)
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Three-Dimensional Technology and Bone Morphogenetic Protein in Frontal Bone Reconstruction
- 2006
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Ingår i: Journal of Craniofacial Surgery. ; 17:2, s. 275-279
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Tidskriftsartikel (refereegranskat)abstract
- Osteoinductive bone morphogenetic proteins (BMPs) may be used in humans to facilitate healing of bony defects. The effect of different BMPs is, as with many other growth factors, highly dependent on the delivery vehicle. Bovine type I collagen is currently used in the clinical setting as a carrier and has been approved in several countries for human use. Here, we report the reconstruction of a frontal bone defect using heparin together with bovine type I collagen, hyaluronic acid, and fibrin as vehicles for BMP-2. A bony structure was created on the back of the patient by treating the latissimus dorsi muscle with the growth factor. A polyamide mold was used as a template to achieve the desired shape. The bone structure was transplanted into the defect site via microsurgical techniques. Although the prefabricated bone was not large enough tocover the entire frontal defect, the reconstruction was completed by using an additional cranial implant.
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| 8. |
- Berglin, Ewa, 1955-
(författare)
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Predictors of disease onset and progression in early rheumatoid arthritis : A clinical, laboratory and radiological study
- 2006
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- To diagnose rheumatoid arthritis (RA) during the early stages of the disease is often difficult. The disease course shows great inter-individual variation from mild, self-limiting to very severe destruc-tive disease with extra-articular manifestations. Early aggressive treatment with potentially toxic drugs has been shown to improve the long-term outcome. Thus, it is desirable to make an early reliable di-agnosis and to identify those patients who would benefit from being treated most aggressively. The aim of this thesis was to evaluate laboratory and clinically markers of inflammation as predic-tors of disease course, to compare dual-energy X-ray absorptiometry (DXA) and conventional radiog-raphy (CR) as measures of joint destruction and to investigate the significance of antibodies against cyclic citrullinated peptide (anti-CCP antibodies), rheumatoid factors (RFs) and HLA shared epitope (SE) alleles for the relative risk of future development of RA and as predictors of disease severity in patients with early RA. Patients with RA of recent onset are included in the early RA programme at the Department of Rheumatology, University Hospital, Umeå and are followed longitudinally. The prediction of markers of inflammation for bone loss and radiological outcome was analyzed in the first 43 patients recruited. Radiographs of hands and feet (Larsen score) and bone mineral density (BMD) in hands (DXA), were assessed at baseline, after 1 and 2 years. The disease activity was evaluated clinically and by labora-tory tests. Radiological damage increased significantly during the study and was particularly corre-lated with Larsen score at baseline. BMD in hands decreased significantly in postmenopausal women and the decrease was greater than in healthy matched controls. Radiological progression and bone loss in hands was retarded by an early response to therapy. In a case-control study within the Medical Biobank and the Maternity cohort of Northern Sweden, patients from the early RA programme were identified among blood donors from whom samples had been collected years before onset of symptoms. The prevalence of anti-CCP antibodies and RFs (IgA-RF, IgG-RF and IgM-RF) was investigated in samples from 83 individuals (pre-patients) and com-pared with matched controls. SE alleles were assessed in a sub-group of 59 individuals. Anti-CCP antibodies and RFs preceded onset of RA by several years and increased in prevalence closer to dis-ease onset. Anti-CCP antibodies and IgA-RF significantly predicted the onset of RA. The combination of anti-CCP antibodies and SE alleles was associated with a high relative risk for future development of RA. In a later co-analysis between the register of patients in the early RA programme (n=138) and the Medical Biobank and the Maternity cohort, 93 pre-patient samples were identified. The significance of SE alleles and of the presence of anti-CCP antibodies and RFs before and at disease onset for disease activity and severity was studied. Radiographs of hands and feet were assessed at baseline and after 2 years (Larsen score). The presence of anti-CCP antibodies in pre-patient samples and at baseline was associated with radiological damage, as was presence of all RFs at baseline. A higher titre of anti-CCP antibodies was associated with greater radiological progression. The titre was lowered by a therapeutic response. In multiple logistic regression analyses anti-CCP antibodies, IgA-RF, ESR and swollen joint count predicted greater radiological progression, whilst a therapeutic response predicted a lesser pro-gression. In conclusion, anti-CCP antibodies and IgA-RF are predictors for future onset of RA and for radio-logical destruction and progression. The combination of anti-CCP antibodies and SE alleles is associ-ated with a high relative risk for future RA. Therapeutic response decreases the radiological progres-sion and the bone loss in hands and lowers the titre of anti-CCP antibodies. Conventional radiography is a better measure of joint destruction than DXA.
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| 9. |
- Björk, Mathilda, 1977-
(författare)
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Aspects of Disability in Rheumatoid Arthritis : a five-year follow-up in the Swedish TIRA project
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Rheumatoid arthritis (RA) is a progressive disease, often leading to disability. Because the disease course develops rapidly during the first years after diagnosis, more knowledge is needed about the early disease course to minimize later disability. This thesis describes the course of disability in early RA such as hand function, pain intensity, activity limitation and sick leave. In addition, this thesis compares disability between women and men and compares disability between RA patients and referents.This thesis is primarily based on data from the 320 patients that were included in the multi-centre project in Sweden called ‘Early interventions in rheumatoid arthritis’ (TIRA). A wide range of outcome variables was registered between 1996 and 2006 during regular follow-ups from time for diagnosis through the eight-year follow-up. Outcome regarding disease activity and disability of RA patients still remaining in TIRA at the three and five year follow-up respectively are used in this thesis. Data concerning sick leave were obtained for the patients during six years (1993-2001) – three years before and three years after diagnosis. Referents were included in two of the studies. Data regarding disability in referents were obtained according to hand function and activity limitation using the Health Assessment Questionnaire (HAQ). Data for sick leave were obtained for six years in referents, for the same period as the RA patients.For most variables, disability in RA was most pronounced at time of diagnosis but before intervention started. Disability was then reduced already at the 3-month follow-up and thereafter affected but stable during the following five years. The exception was participation, reflected by sick leave, a variable that was stable from inclusion to three years from diagnosis. Activity limitation, pain intensity and sick leave in RA that represents different aspects of disability were explained by other aspects of disability and contextual factors rather than by disease activity. RA affects women and men differently in some aspects. Women had more severe course of activity limitations than men according to HAQ. Men were more affected than women in range of motion, although the differences were small in a clinical perspective. However, pain intensity and frequency of sick leave did not differ between women and men. Patients with RA have pronounced disability in relation to referents although several variables improve soon after diagnosis. This discrepancy refers to hand function as well as activity limitations and sick leave. The frequency of sick leave increased during the year before diagnosis in relation to referents and was thereafter high compared to sick leave in referents.
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| 10. |
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| 11. |
- Björk, Mathilda, et al.
(författare)
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Hand Function and Activity Limitation According to Health Assessment Questionnaire in Patients with Rheumatoid Arthritis and Healthy Referents : 5-Year Followup of Predictors of Activity Limitation (The Swedish TIRA Project)
- 2007
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Ingår i: Journal of Rheumatology. - Toronto, Ontario, Canada : Journal of Rheumatology Publishing Co. Ltd.. - 0315-162X .- 1499-2752. ; 34:2, s. 296-302
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Tidskriftsartikel (refereegranskat)abstract
- Objective: This study identifies baseline predictors of future activity limitation in rheumatoid arthritis (RA). To reinforce the utility of instruments assessing functional ability/activity limitation, we used reference data from healthy referents. Methods: This study includes 189 patients (69% women) with recent-onset RA (onset of joint swelling not more than 12 months at diagnosis) in a prospective cohort ("the Swedish TIRA project") during 27 months from 1996 through 1998. Regular followups were done for a period of 5 years, and 123 healthy persons (50% women) were recruited as referents. Hand function was assessed by the "grip ability test (GAT)" and "signals of functional impairment" (SOFI). Grip force was measured with the electronic device GrippitTM. Activity limitation was assessed with the Swedish version of the Health Assessment Questionnaire (HAQ). Results: Throughout the study and for both sexes, GAT, grip force, SOFI-hand, and HAQ were significantly different for the patients compared to healthy referents. In the healthy referents, HAQ was mainly related to age and GAT, whereas in RA HAQ was most obviously linked to grip force. Five years after diagnosis only 8% of HAQ outcome was explained by the baseline measures: HAQ, grip force, SOFI-lower limb, sex, walking speed, and GAT. Conclusion: Our study provides valuable reference data for several functional ability and activity limitation measures. The HAQ score was explained by different variables in healthy referents compared to patients with RA. Five years after diagnosis only 8% of HAQ outcome was explained by the variables assessed at inclusion.
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| 12. |
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| 13. |
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| 14. |
- Björk, Mathilda, et al.
(författare)
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Hand function in women and men with early rheumatoid arthritis : A prospective study over three years (the Swedish TIRA project)
- 2006
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Ingår i: Scandinavian Journal of Rheumatology. - : Informa Healthcare. - 0300-9742 .- 1502-7732. ; 35:1, s. 15-19
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To describe the course of hand function in women and men during the first 3 years after diagnosis of recent-onset rheumatoid arthritis (RA), to investigate sex differences in hand function, and to study correlations between and within hand function assessments. Methods: A total of 276 patients (69% women) with RA of a maximal duration of 12 months were recruited to the study. Hand function was assessed by the Grip Ability Test (GAT) and Signals of Functional Impairment (SOFI). Peak and average grip force over 10 s in the right and left hand was measured by an electronic device.Results: Hand function was affected at diagnosis, but had improved significantly at the 3-months' follow-up and then remained stable (but still affected) in both women and men. As assessed by SOFI, hand function was worse in men than in women, whereas women had significantly lower grip force. GAT, grip force, and SOFI correlated weakly. The average and peak values of grip force correlated strongly, as did the grip force in the right and the left hand. Conclusion: Hand function was profoundly affected at diagnosis of RA, but improved significantly within 3 months and remained stable (but still affected) over 3 years. As expected, women on average had significantly lower grip force than men.
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| 15. |
- Carlsson, Alexandra Dimitrijevic, et al.
(författare)
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Orofacial pain in juvenile idiopathic arthritis is associated with stress as well as psychosocial and functional limitations
- 2019
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Ingår i: Pediatric Rheumatology. - : BioMed Central (BMC). - 1546-0096. ; 17:1
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Tidskriftsartikel (refereegranskat)abstract
- Background The aim of this study was to investigate relations between psychosocial factors, signs and symptoms of orofacial pain and jaw dysfunction in patients with juvenile idiopathic arthritis (JIA). Methods Forty-five patients with JIA (median age 12 years) and 16 healthy matched controls (median age 13 years) were examined according to the diagnostic criteria for temporomandibular disorders (DC/TMD). The subjects answered the DC/TMD questionnaires regarding psychosocial factors (pain intensity, pain-related disability, depression, stress, catastrophizing, pain locations and jaw function). Results JIA patients with orofacial pain had higher degree of stress, depression, catastrophizing and jaw dysfunction compared to subjects without. In turn, these factors were associated with orofacial pain intensity. Also, patients with orofacial pain had higher systemic inflammatory activity. Conclusions Orofacial pain in patients with JIA is associated with stress, psychological distress, jaw dysfunction and loss of daily living activities. Pain intensity seems to be the major pain aspect related to these factors. In addition, systemic inflammatory activity appears to be an important factor contributing to orofacial pain in JIA.
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| 16. |
- Cedergren, Jan, et al.
(författare)
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Inducible nitric oxide synthase is expressed in synovial fluid granulocytes
- 2002
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Ingår i: Clinical Experimental Immunology. - : Oxford University Press (OUP). - 0009-9104 .- 1365-2249. ; 130, s. 150-155
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Tidskriftsartikel (refereegranskat)abstract
- The objective of the study was to evaluate the NO-producing potential of synovial fluid (SF) cells. SF from 15 patients with arthritis was compared with blood from the same individuals and with blood from 10 healthy controls. Cellular expression of inducible nitric oxide synthase (iNOS) was analysed by flow cytometry. High-performance liquid chromatography was used to measure L-arginine and L-citrulline. Nitrite and nitrate were measured colourimetrically utilizing the Griess' reaction. Compared to whole blood granulocytes in patients with chronic arthritis, a prominent iNOS expression was observed in SF granulocytes (P < 0.001). A slight, but statistically significant, increase in iNOS expression was also recorded in lymphocytes and monocytes from SF. L-arginine was elevated in SF compared to serum (257 ± 78 versus 176 ± 65 µmol/l, P = 0.008), whereas a slight increase in L-citrulline (33 ± 11 versus 26 ± 9 µmol/l), did not reach statistical significance. Great variations but no significant differences were observed comparing serum and SF levels of nitrite and nitrate, respectively, although the sum of nitrite and nitrate tended to be elevated in SF (19.2 ± 20.7 versus 8,6 ± 6.5 µmol/l,P = 0.054). Synovial fluid leucocytes, in particular granulocytes, express iNOS and may thus contribute to intra-articular NO production in arthritis.
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| 17. |
- Cedergren, Jan, et al.
(författare)
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Inducible nitric oxide synthase (NOS II) is constitutive in human neutrophils
- 2003
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Ingår i: APMIS. - : Wiley. - 0903-4641 .- 1600-0463. ; 111:10, s. 963-968
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Tidskriftsartikel (refereegranskat)abstract
- The objective was to study the expression of inducible nitric oxide synthase (NOS II) in and NO production by human blood neutrophils and in in vivo exudated neutrophils. Cellular expression of NOS II was evaluated by flow cytometry in whole blood, in isolated blood neutrophils, and in neutrophils obtained by exudation in vivo into skin chambers. Neutrophil NOS II was also demonstrated by Western blotting. Uptake of 3H-labelled L-arginine was studied in vitro and NOS activity measured in a whole cell assay by the conversion of 3H-arginine to 3H-citrulline. In contrast to unseparated blood cells, NOS II was demonstrable both in isolated blood neutrophils and exudated cells. The failure to detect NOS II by flow cytometry in whole blood cells thus proved to be due to the quenching effect of hemoglobin. Western blotting revealed a 130 kD band corresponding to NOS II in isolated blood neutrophils, but detection was dependent on diisopropylfluorophosphate for proteinase inhibition. L-arginine was taken up by neutrophils, but enzymatic activity could not be demonstrated. We conclude that human neutrophils constitutively express NOS II, but that its demonstration by FITC-labelling is inhibited by hemoglobin-mediated quenching in whole blood samples.
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| 18. |
- Cedergren, Jan, et al.
(författare)
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Intracellular oxidative activation in synovial fluid neutrophils from patients with rheumatoid arthritis but not from other arthritis patients
- 2007
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Ingår i: Journal of Rheumatology. - 0315-162X .- 1499-2752. ; 34:11, s. 2162-2170
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To compare total and intracellular oxidative activation of blood and synovial fluid (SF) neutrophils from patients with rheumatoid arthritis (RA) and other arthritides with blood donor neutrophils. Methods: Peripheral blood and SF samples were obtained from 26 gonarthritis patients (13 RA, 13 non-RA) attending the rheumatology unit for therapeutic joint aspiration. Isolated neutrophils were stimulated by a formylated tripeptide (fMLF) or by microbeads coated with collagen-I. Formation of superoxide-anion-derived reactive oxygen species (ROS) was studied by luminol-enhanced chemiluminescence. Paired samples of blood and SF neutrophils from patients with active arthritis were compared with blood neutrophils from patients in remission and from 47 healthy blood donors. Results: SF neutrophils from patients with RA, but not from non-RA patients, showed high baseline intracellular ROS production. Blood neutrophils from arthritis patients in remission existed in a primed state as revealed by more rapid oxidative response after collagen-bead challenge and a more pronounced response after fMLF stimulation compared to healthy blood donors. Blood neutrophils from RA patients with ongoing gonarthritis, however, did not differ from healthy blood donors concerning oxidative activation, whereas blood neutrophils from non-RA patients with gonarthritis showed a significantly lower peak ROS production. Conclusions: A novel finding with pathogenetic implications in our study is that SF neutrophils from patients with RA, but not other arthritides, are activated and produce ROS intracellularly. This implies that synovial neutrophils in RA are engaged in the processing of endocytosed material.
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| 19. |
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| 20. |
- Cedergren, Jan, 1965-
(författare)
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Radical aspects on arthritis : the role of neutrophil generation of nitric oxide and superoxide in inflammatory conditions
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The polymorphonuclear neutrophil granulocytes (neutrophils) are gaining renewed interest regarding their involvement in chronic inflammatory disorders, including rheumatoid arthritis (RA). Besides phagocytic and destructive capabilities, neutrophils have regulatory roles, e.g. by influencing responses from dendritic cells and lymphocytes. Several animal models have revealed that neutrophils are crucial for the initiation and maintenance of chronic inflammatory diseases. Neutrophil function is highly dependent on their ability to produce superoxide, an oxygen radical which can be further metabolized to other free radicals. Whether or not neutrophils are capable of producing the oxygen radical nitric oxide (NO˙) has been a matter of debate.In this thesis it was shown that freshly isolated neutrophils from the joint cavity of patients with RA, but not from other arthritis patients, had ongoing intracellular production of superoxide, indicating the processing of ingested material.The finding that joint neutrophils, but seemingly not circulating cells, expressed the NO-inducing enzyme iNOS, led to a series of experiments aimed to elucidate where in the exudative process this enzyme could first be detected. We could finally, for the first time, present evidence that human neutrophils actually express iNOS constitutively. Our data also suggest that neutrophil iNOS may be membrane associated, thus differing from the cytosolic location in other cell types. Since NOS activity was not demonstrated in isolated cells, the notion that neutrophil iNOS is regulated primarily at the transcriptional level must be questioned. NO production from iNOS requires the presence of its substrate, L-arginine. To test the hypothesis that neutrophil arginase prevents neutrophil NO-production, we investigated whether arginase inhibition affects neutrophil NO-dependent oxidative function. Initial data revealed a difference in the effect of arginase inhibition comparing neutrophil stimulus with a soluble formylated tri-peptide (fMLF) and integrin-mediated stimulation with particle-bound collagen type-1. This led to the hypothesis that integrin-ligation on neutrophils induces extracellular liberation of arginase, which was confirmed both by measuring arginase and its enzyme activity. The findings in this thesis may be important not only regarding the role of neutrophils in chronic joint inflammation, but also as a link in the accelerated atherosclerosis observed in chronic inflammatory disorders, e.g. RA.
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| 21. |
- Chalise, Jaya Prakash
(författare)
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Immune tolerance by interferon-alpha in experimental arthritis
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Type I Interferons (mainly IFN-α & IFN-β) belong to a family of cytokines that possess strong antiviral and immunomodulatory properties. Pro- and/or anti-inflammatory effects of type I IFN have been observed in infectious diseases and several autoimmune diseases including SLE, MS, RA and experimental models thereof, but what defines either outcome is largely obscure. The main aim of this thesis is to understand how IFN-α may act anti-inflammatory in a model of antigen-induced arthritis (AIA). In this model, mice are sensitised with methylated-BSA (mBSA) emulsified in Freund’s adjuvant at day 1 and 7 followed by intra-articular injection of mBSA in the knee joint at day 21, which induces arthritis within 1 week.Administration of IFN-α at the time of mBSA sensitisations (day 1 and day 7) but not at induction of arthritis (day 21) clearly protected against arthritis in a type I IFN receptor dependent manner. Humoral immunity might not be involved in this protection as the levels of antigen-specific IgG (total, IgG1, IgG2a and IgG2b), IgA, IgE in serum were not altered in IFN-α treated mice. However, IFN-α-protection was accompanied by delayed and decreased antigen-specific proliferative responses in spleen and lymph node cells ex vivo, including impaired proliferative recall responses after intra-articular antigenic challenge.In the course of AIA, IFN-α inhibited the increase of circulatory IL-6, IL-10, IL-12, and TNF in the sensitisation phase (day 0-21) and also the re-call response of IL-1β, IL-10, IL-12, TNF, IFN-γ, and IL-17 induced by intra-articular mBSA challenge in arthritis phase (day 21-28). This IFN-α-inhibition of cytokines was also apparent in mBSA-re-stimulated spleen and lymph node cell cultures ex vivo, including inhibited cytokine production in CD4+ T helper cells and macrophages. In contrast to the inhibition of pro-inflammatory cytokines, the levels of immunomodulatory TGF-β was clearly enhanced in IFN-α-treated mice, both in serum and in re-stimulated leucocytes cultures including both macrophages, especially in the sensitisation phase, and in CD4+ T cells in the arthritis phase. By inhibiting TGF-β signalling in vivo, the protective effect of IFN-α was shown to be dependent on TGF-β signalling in the sensitisation phase.The cytokine TGF-β is an activator of the indoleamine 2,3 dioxygnese (IDO1), a potent immuneregulatory component that acts via enzymatic production of kynurenine (Kyn) and signalling activity. The IFN-α-protective effect in AIA was associated with both increased expression and enzymatic activity of IDO1 and the IFN-α-protection was totally ablated in mice lacking IDO1 expression (IDO1 KO mice) and in mice treated with the inhibitor of the enzymatic activity of IDO1 (1-Methyl Tryptophan; 1-MT). Interestingly, administration of the IDO-metabolite Kyn protected mice from AIA in an IFNARindependent manner. These observations show that the IDO1 enzymatic activity is important for the protective effect of IFN-α. Using 1-MT, it was further shown that the enzymatic activity of IDO1 was, like TGF-β, crucial only at the sensitisation but not in the arthritis phase of AIA for IFN-α to protect against arthritis. Instead, IDO1’s non-enzymatic signalling activity, characterized by sustained expression of IDO1 and non-canonical NF-κB activation in pDCs, was observed in the arthritis phase in spleen cells from mice treated with IFN-α.Regulatory T cells (Treg cells) were also found to be important for IFN-α-protection in AIA. Transient depletion of Treg cells by diphtheria toxin in DEREG mice in the arthritis phase, but not during the sensitisation phase abolished IFN-α-protection. Treatment with IFN-α enhanced the numbers of Treg cells in the course of AIA and their function; compared to untreated mice, Treg cells isolated at day 10 and 20 of AIA from IFN-α- treated mice exhibited higher suppressive activity against mBSA-stimulated proliferation of responder T cells. The enhancing effect of IFN-α on Treg cell numbers was observed in blood, spleen, LNs and also in ex-vivo cultures of leucocytes re-stimulated with mBSA and IFN-α. Although IFN-α clearly increased the suppressive activity of Treg cells, adoptive transfer of Treg cells from mBSA immunized mice, regardless of IFN-α treatment, prevented the development of arthritis.ConclusionIn the presence of IFN-α during antigen sensitisation, a state of tolerance is established, which is able to prevent joint inflammation induced by antigenic re-challenge. This immunological tolerance is created in the sensitisation phase of AIA and is characterized by inhibition of pro-inflammatory cytokines, increased TGF-β production and activity of the IDO1 enzyme, the latter two being indispensable for IFN-α-induced protection. Administration of Kyn, the metabolite of the enzymatic activity of IDO1, in the sensitisation phase also protected against AIA downstream of type I IFN signalling. In the arthritis phase regulatory T cells, whose numbers and suppressive capacity was clearly enhanced by IFN-α, mediate the actual prevention of arthritis development in IFN-α-treated animals. We have thus identified molecular and cellular components of the anti-inflammatory program elicited by IFN-α including Kyn that may not have the pro-inflammatory effects associated with IFN.
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| 22. |
- Dahle, Charlotte, 1956-, et al.
(författare)
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Methods of choice for diagnostic antinuclear antibody (ANA) screening : Benefit of adding antigen-specific assays to immunofluorescence microscopy
- 2004
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Ingår i: Journal of Autoimmunity. - : Elsevier BV. - 0896-8411 .- 1095-9157. ; 22:3, s. 241-248
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Tidskriftsartikel (refereegranskat)abstract
- Objectives. To evaluate and compare the performances of three enzyme-immunoassays (EIAs) and a double radial immunodiffusion (DRID) test in addition to immunofluorescence (IF) microscopy for routine laboratory screening of patient sera sent for antinuclear antibody (ANA) analysis. Methods. 3079 consecutive patient sera sent for routine testing of ANA were analysed by IF microscopy on HEp-2 cells (IF-ANA), three different ANA-EIAs, and a DRID test for antibodies against extractable nuclear antigens. The IF-ANA and DRID tests were regarded as reference methods. Results. By IF-ANA and/or DRID, 375 sera (12%) turned out ANA-positive. A further 171 sera (6%) were positive by EIA, but could not be confirmed either by IF microscopy or DRID. 32 of the 375 ANA-positive (9%) sera were negative by IF microscopy, but had precipitating antibodies against Ro/SS-A (52 and/or 60 kD). Conclusions. Different assays for ANA analysis give overlapping results to a certain extent, but are by no means interchangeable. Thus, different ANA tests reflect different aspects of these autoantibodies. The diagnostic utility of ANA testing still mainly refers to IF-microscopy and precipitin tests. IF-ANA should not be abandoned as the golden standard in clinical routine, until diagnostic and classification criteria for systemic lupus erythematosus and other systemic inflammatory autoimmune diseases have been revised. However, in addition we strongly advocate that a specific test for anti-Ro/SS-A antibodies is always included.
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| 23. |
- Dahlström, Örjan, et al.
(författare)
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A simple method for heuristic modeling of expert knowledge in chronic disease : identification of prognostic subgroups in rheumatology
- 2008
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Ingår i: eHealth Beyond the Horizon – Get IT There. - : IOS Press. - 9781586038649 - 9781607503330 ; , s. 157-162
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Konferensbidrag (refereegranskat)abstract
- Identification of prognostic subgroups is of key clinical interest at the early stages of chronic disease. The aim of this study is to examine whether representation of physicians' expert knowledge in a simple heuristic model can improve data mining methods in prognostic assessments of patients with rheumatoid arthritis (RA). Five rheumatology consultants' experiences of clinical data patterns among RA patients, as distinguished from healthy reference populations, were formally represented in a simple heuristic model. The model was used in K-mean-clustering to determine prognostic subgroups. Cross-sectional validation using physician's global assessment scores indicated that the simple heuristic model performed better than crude data made in identification of prognostic subgroups of RA patients. A simple heuristic model of experts' knowledge was found useful for semi-automatic data mining in the chronic disease setting. Further studies using categorical baseline data and prospective outcome variables are warranted and will be examined in the Swedish TIRA-program.
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| 24. |
- Dahlström, Örjan, et al.
(författare)
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Designing a decision support system for existing clinical organizational structures : Considerations from a rheumatology clinic
- 2006
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Ingår i: Journal of medical systems. - : Springer Science and Business Media LLC. - 0148-5598 .- 1573-689X. ; 30:5, s. 325-331
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to identify the social and organizational requirements for a decision support system (DSS) to be implemented in a clinical rheumatology setting, utilizing data-mining techniques. Field observations and focus group interviews were used for data collection. The decision-making was found to be situated, patient-focused, and long-term in nature. At the same time, the main part of peer-to-peer communication was informal. Patient records were involved in almost every decision. The conclusion is that the main challenges, when introducing a DSS at a rheumatology unit, are adapting the system to informal communication structures and integrating it with patient records. Considering incentive structures, understanding workflow and incorporating awareness are relevant issues when addressing these issues in future studies.
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- Dahlström, Örjan, 1973-, et al.
(författare)
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Prognostic components and predictive modelling of prognosis in early RA
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Introduction: There is a need for tools that are easy to use in clinical practice supporting decision making upon treatment in early rheumatoid arthritis (RA). Aim: The aim was to identify components of prognosticators in early RA and to identify individual patients with a poor prognosis as early as possible. Methods: Two cohorts from the Swedish TIRA project including 320+408 patients with recent onset RA were included in the study. Disease activity was measured by C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and the 28-joint count disease activity score (DAS-28), and by the physicians’ global assessment of disease activity (PGA). Disability was assessed as activity limitation by the Swedish version of the Health Assessment Questionnaire (HAQ) and impairment was reported by pain on a visual analogue scale of 0–100 mm. Serological markers were rheumatoid factor (RF) and anti-CCP. RF was measured at the time for diagnosis, and anti-CCP at the time of diagnosis or at one or some of the follow-ups. If at least one anti-CCP test was positive, the patient was judged to be anti-CCP-positive. Assuming different clinical practice in the different cohorts, two different treatment strategies were assumed based on clinical practice in real-world settings. Principal Component Analysis and Multiple Linear Regression Analysis were used to identify prognosticators. Prediction rules were identified by data-driven approach, controlling for different treatment strategies. Results: Progression of disease and disability measures and inflammation measures the first three months after inclusion predicted a considerable part of DAS-28 at the 1-year follow-up. Serological markers had a larger explanatory power for men than for women. Anti-CCP was a significant predictor for men, but not for women. Two versions of rules, one for women and one for men, predicting good or poor prognosis at one year after inclusion were produced by using measures of disability (Health Assessment Questionnaire), DAS-28, relative change in DAS-28 during first three months, sex, and test of anti-CCP. The rules demanded high prognostic specificity but the prognostic sensitivity was moderate. Conclusion: A considerable part of DAS-28 at one year after inclusion could be explained by the first 3 months’ progression of disease, disability and inflammation. Anti-CCP was predictive for men but not for women, and needs further investigation. A decision tree predicting poor prognosis among individual early RA-patients showed high specificity and moderate sensitivity on a validationcohort. The medical informatics approach used, controlling for different treatment strategies, yields promising results and further studies will control for more specific differences in treatment strategies, e.g. different DMARDs initiated.
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