| 1. |
- Dezfouli, Mahya, et al.
(författare)
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Newborn Screening for Presymptomatic Diagnosis of Complement and Phagocyte Deficiencies
- 2020
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Ingår i: Frontiers in Immunology. - : FRONTIERS MEDIA SA. - 1664-3224. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- The clinical outcomes of primary immunodeficiencies (PIDs) are greatly improved by accurate diagnosis early in life. However, it is not common to consider PIDs before the manifestation of severe clinical symptoms. Including PIDs in the nation-wide newborn screening programs will potentially improve survival and provide better disease management and preventive care in PID patients. This calls for the detection of disease biomarkers in blood and the use of dried blood spot samples, which is a part of routine newborn screening programs worldwide. Here, we developed a newborn screening method based on multiplex protein profiling for parallel diagnosis of 22 innate immunodeficiencies affecting the complement system and respiratory burst function in phagocytosis. The proposed method uses a small fraction of eluted blood from dried blood spots and is applicable for population-scale performance. The diagnosis method is validated through a retrospective screening of immunodeficient patient samples. This diagnostic approach can pave the way for an earlier, more comprehensive and accurate diagnosis of complement and phagocytic disorders, which ultimately lead to a healthy and active life for the PID patients.
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| 2. |
- Lim, Che Kang, et al.
(författare)
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Reversal of Immunoglobulin. A Deficiency in Children
- 2015
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Ingår i: Journal of Clinical Immunology. - : Springer Science and Business Media LLC. - 0271-9142 .- 1573-2592. ; 35:1, s. 87-91
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Tidskriftsartikel (refereegranskat)abstract
- Immunoglobulin A deficiency (IgAD) is the most common primary immunodeficiency in the general population. It is defined as a serum IgA level below or equal to 0.07 g/l with normal IgM and IgG levels in children over the age of 4. However, a few cases of reversal of IgAD at later ages have been observed previously, especially in pediatric patients. This study aimed at investigating the frequency of reversal in a large cohort of children and young adults in order to evaluate the present definition of IgAD. Clinical laboratory records from 654 pediatric IgA deficient patients, 4-13 years of age, were retrieved from five university hospitals in Sweden. Follow up in the children where IgA serum levels had been routinely measured was subsequently performed. In addition, follow up of the IgA-levels was also performed at 4, 8 and 16 years of age in children who were IgA deficient at the age of 4 years in a Swedish population-based birth cohort study in Stockholm (BAMSE). Nine out of 39 (23.1 %) children who were identified as IgAD at 4 years of age subsequently increased their serum IgA level above 0.07 g/L. The average age of reversal was 9.53 +/- 2.91 years. In addition, 30 out of the 131 (22.9 %) children with serum IgAD when sampled between 5 and 9.99 years of age reversed their serum IgA level with time. The BAMSE follow up study showed a reversal of IgAD noted at 4 years of age in 8 out of 14 IgAD children at 16 years of age (5 at 8 years of age) where 4 were normalized their serum IgA levels while 4 still showed low serum levels of IgA, yet above the level defining IgAD. The results indicate that using 4 years of age, as a cut off for a diagnosis of IgAD may not be appropriate. Our findings suggest that a diagnosis of IgAD should not be made before the early teens using 0.07 g/L of IgA in serum as a cut off.
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| 3. |
- Wang, Ning, et al.
(författare)
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Selective IgA deficiency in autoimmune diseases
- 2011
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Ingår i: Molecular Medicine. - Baltimore, Md. : Johns Hopkins University Press. - 1076-1551 .- 1528-3658. ; 17:11-12, s. 1383-
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Forskningsöversikt (refereegranskat)abstract
- Selective IgA deficiency (IgAD) is the most common primary immunodeficiency in Caucasians. It has previously been suggested to be associated with a variety of concomitant autoimmune diseases. In this review, we present data on the prevalence of IgAD in patients with Graves' disease (GD), systemic lupus erythematosus (SLE), type 1 diabetes (T1D), celiac disease (CD), myasthenia gravis (MG) and rheumatoid arthritis (RA) based both on our own, recent, large scale screening results and literature data. Genetic factors are important for the development of both IgAD and various autoimmune disorders, including GD, SLE, T1D, CD, MG and RA, and a strong association with the MHC region has been reported. In addition, non-MHC genes, such as IFIH1 and CLEC16A, are also associated with the development of IgAD and some of the above diseases. This indicates a possible common genetic background. In this review, we present suggestive evidence for a shared genetic predisposition between these disorders.
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| 4. |
- Wang, Ning, et al.
(författare)
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Serological Assessment for Celiac Disease in IgA Deficient Adults
- 2014
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Ingår i: PLOS ONE. - : Public Library of Science. - 1932-6203. ; 9:4, s. 0093180-
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: Selective immunoglobulin A deficiency is the most common primary immunodeficiency disorder that is strongly overrepresented among patients with celiac disease (CD). IgG antibodies against tissue transglutaminase (tTG) and deamidated gliadin peptides (DGP) serve as serological markers for CD in IgA deficient individuals, although the diagnostic value remains uncertain. The aim of this study was to investigate the prevalence of these markers in a large cohort of IgA deficient adults with confirmed or suspected CD and relate the findings to gluten free diet. Methods: Sera from 488,156 individuals were screened for CD in seven Swedish clinical immunology laboratories between 1998 and 2012. In total, 356 out of 1,414 identified IgA deficient adults agreed to participate in this study and were resampled. Forty-even IgA deficient blood donors served as controls. Analyses of IgG antibodies against tTG and DGP as well as HLA typing were performed and a questionnaire was used to investigate adherence to gluten free diet. Available biopsy results were collected. Results: Out of the 356 IgA deficient resampled adults, 67 (18.8%) were positive for IgG anti-tTG and 79 (22.2%) for IgG anti-DGP, 54 had biopsy confirmed CD. Among the 47 IgA deficient blood donors, 4 (9%) were positive for IgG anti-tTG and 8 (17%) for anti- DGP. Four were diagnosed with biopsy verified CD, however, 2 of the patients were negative for all markers. Sixty-eight of 69 individuals with positive IgG anti-tTG were HLA-DQ2/DQ8 positive whereas 7 (18.9%) of the 37 individuals positive for IgG anti-DGP alone were not. Conclusions: IgG anti- tTG seems to be a more reliable marker for CD in IgA deficient adults whereas the diagnostic specificity of anti-DGP appears to be lower. High levels of IgG antibodies against tTG and DGP were frequently found in IgA deficient adults despite adhering to gluten free diet.
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| 5. |
- Abelson, Anna-Karin, et al.
(författare)
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No evidence of association between genetic variants of the PDCD1 ligands and SLE
- 2007
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Ingår i: Genes and Immunity. - : Springer Science and Business Media LLC. - 1466-4879 .- 1476-5470. ; 8:1, s. 69-74
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Tidskriftsartikel (refereegranskat)abstract
- PDCD1, an immunoreceptor involved in peripheral tolerance has previously been shown to be genetically associated with systemic lupus erythematosus (SLE). PDCD1 has two ligands whose genes are located in close proximity on chromosome 9p24. Our attention was drawn to these ligands after finding suggestive linkage to a marker (gata62f03, Z=2.27) located close to their genes in a genome scan of Icelandic families multiplex for SLE. Here, we analyse Swedish trios (N=149) for 23 single nucleotide polymorphisms (SNPs) within the genes of the PDCD1 ligands. Initially, indication of association to eight SNPs was observed, and these SNPs were therefore also analysed in Mexican trios (N=90), as well as independent sets of patients and controls from Sweden (152 patients, 448 controls) and Argentina (288 patients, 288 controls). We do not find support for genetic association to SLE. This is the first genetic study of SLE and the PDCD1 ligands and the lack of association in several cohorts implies that these genes are not major risk factors for SLE.
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| 6. |
- Delgado-Vega, Angélica M., et al.
(författare)
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Fine mapping and conditional analysis identify a new mutation in the autoimmunity susceptibility gene BLK that leads to reduced half-life of the BLK protein
- 2012
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Ingår i: Annals of the Rheumatic Diseases. - : BMJ. - 0003-4967 .- 1468-2060. ; 71:7, s. 1219-1226
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Tidskriftsartikel (refereegranskat)abstract
- ObjectivesTo perform fine mapping of the autoimmunity susceptibility gene BLK and identify functional variants involved in systemic lupus erythematosus (SLE).MethodsGenotyping of 1163 European SLE patients and 1482 controls and imputation were performed covering the BLK gene with 158 single-nucleotide polymorphisms. Logistic regression analysis was done using PLINK and conditional analyses using GENABEL's test score. Transfections of BLK constructs on HEK293 cells containing the novel mutation or the wild type form were analysed for their effect on protein half-life using a protein stability assay, cycloheximide and western blot. CHiP-qPCR for detection of nuclear factor. B (NFkB) binding.ResultsFine mapping of BLK identified two independent genetic effects with functional consequences: one represented by two tightly linked associated haplotype blocks significantly enriched for NF kappa B-binding sites and numerous putative regulatory variants whose risk alleles correlated with low BLK mRNA levels. Binding of NFkBp50 and p65 to an associated 1.2 Kb haplotype segment was confirmed. A second independent genetic effect was represented by an Ala71Thr, low-frequency missense substitution with an OR = 2.31 (95% CI 1.38 to 3.86). The 71Thr decreased BLK protein half-life.ConclusionsThese results show that rare and common regulatory variants in BLK are involved in disease susceptibility and both, albeit independently, lead to reduced levels of BLK protein.
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| 7. |
- Grosso, Giorgia, et al.
(författare)
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The Complex Relationship between C4b-Binding Protein, Warfarin, and Antiphospholipid Antibodies
- 2021
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Ingår i: Thrombosis and Haemostasis. - : Georg Thieme Verlag KG. - 0340-6245 .- 2567-689X. ; 121:10, s. 1299-1309
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Tidskriftsartikel (refereegranskat)abstract
- Background Low levels of total C4b-binding protein (C4BPt), a circulating inhibitor of the classical/lectin complement pathways, were observed in patients with antiphospholipid antibodies (aPLs) and during warfarin treatment. Objectives To investigate the associations between aPL and C4BPt in patients with persistently positive (++) aPL, with/without clinical manifestations and systemic lupus erythematosus (SLE), and in controls. Furthermore, we explored the impact of anticoagulation on C4BPt and in relation to complement activation. Methods In a cross-sectional design we investigated defined subgroups: primary (p) antiphospholipid syndrome (APS, N =67), aPL++ individuals without clinical manifestations (aPL carriers, N =15), SLE-aPL++ ( N =118, among them, secondary [s] APS, N =56), aPL negative (-) SLE (SLE-aPL-, N =291), and 322 controls. Clinical characteristics, including treatment, were tabulated. C4BPt was determined with a magnetic bead method. Complement proteins (C1q, C2, C3, C4, C3a, C3dg, sC5b-9, factor I [FI]) were measured. A mediation analysis was performed to decompose the total effect of aPL++ on C4BPt into the direct and indirect effects of aPL++ through warfarin. Results Overall, C4BPt is 20% decreased in aPL++ patients, regardless of SLE, APS, clinical manifestations, and aPL profile. C4BPt levels associate positively with complement proteins C1q, C2, C3, and C4, and negatively with complement activation product C3dg. In the SLE group, warfarin treatment contributes to approximately half of the C4BPt reduction (9%) Conclusion Both aPLs and warfarin are associated with C4BPt reduction. Complement activation in aPL++ patients may partly be explained by impaired inhibition through depressed C4BPt levels. Further studies are needed to understand the clinical implications.
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| 8. |
- Hamsten, C., et al.
(författare)
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Heat differentiated complement factor profiling
- 2015
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Ingår i: Journal of Proteomics. - : Elsevier BV. - 1874-3919 .- 1876-7737. ; 126, s. 155-162
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Tidskriftsartikel (refereegranskat)abstract
- Complement components and their cascade of reactions are important defense mechanisms within both innate and adaptive immunity. Many complement deficient patients still remain undiagnosed because of a lack of high throughput screening tools. Aiming towards neonatal proteome screening for immunodeficiencies, we used a multiplex profiling approach with antibody bead arrays to measure 9 complement proteins in serum and dried blood spots. Several complement components have been described as heat sensitive, thus their heat-dependent detectability was investigated. Using sera from 16 patients with complement deficiencies and 23 controls, we confirmed that the proteins C1q, C2, C3, C6, C9 and factor H were positively affected by heating, thus the identification of deficient patients was improved when preheating samples. Measurements of C7, C8 and factor I were negatively affected by heating and non-heated samples should be used in analysis of these components. In addition, a proof of concept study demonstrated the feasibility of labeling eluates from dried blood spots to perform a subsequent correct classification of C2-deficiencies. Our study demonstrates the potential of using multiplexed single binder assays for screening of complement components that open possibilities to expand such analysis to other forms of deficiencies.
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| 9. |
- Idborg, Helena, et al.
(författare)
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STRATIFICATION OF SLE PATIENTS FOR IMPROVED DIAGNOSIS AND TREATMENT
- 2013
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Ingår i: Annals of the Rheumatic Diseases. - : BMJ. - 0003-4967 .- 1468-2060. ; 72, s. A80-A80
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Background. Systemic autoimmune diseases (SAIDs) affect about 2% of the population in Western countries. Sufficient diagnostic criteria are lacking due to the heterogeneity within diagnostic categories and apparent overlap regarding symptoms and patterns of autoantibodies between different diagnoses. Systemic lupus erythematosus (SLE) is regarded as a prototype for SAIDs and we hypothesise that subgroups of patients with SLE may have different pathogenesis and should consequently be subject to different treatment strategies.Objectives. Our goal is to find new biomarkers to be used for the identification of more homogenous patient populations for clinical trials and to identify sub-groups of patients with high risk of for example cardiovascular events.Methods. In this study we have utilised 320 SLE patients from the Karolinska lupus cohort and 320 age and gender matched controls. The SLE cohort was characterised based on clinical, genetic and serological data and combined by multivariate data analysis in a systems biology approach to study possible subgroups. A pilot study was designed to verify and investigate suggested subgroups of SLE. Two main subgroups were defined: One group was defined as having SSA and SSB antibodies and a negative lupus anticoagulant test (LAC), i.e., a “Sjögren-like” group. The other group was defined as being negative for SSA and SSB antibodies but positive in the LAC test.i.e. an “APS-like” group. EDTA-plasma from selected patients in these two groups and controls were analysed using a mass spectrometry (MS) based proteomic and metabolomic approach. Pathway analysis was then performed on the obtained data.Results. Our pilot study showed that differences in levels of proteins and metabolites could separate disease groups from population controls. The profile/pattern of involved factors in the complement system supported a division of SLE in two major subgroups, although each individual factor was not significantly different between subgroups. Complement factor 2 (C2) and membrane attack complex (MAC) were analysed in the entire cohort with complementary methods and C2 verifies our results while the levels of MAC did not differ between SLE subgroups. The generated metabolomics data clearly separated SLE patients from controls in both gas chromatography (GC)-MS and liquid chromatography (LC)-MS data. We found for example that tryptophan was lower in the SLE patients compared to controls.Conclusions. Our systems biology approach may lead to a better understanding of the disease and its pathogenesis, and assigning patients into subgroups will result in improved diagnosis and better outcome measures of SLE.
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| 10. |
- Idborg, Helena, et al.
(författare)
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Two subgroups in systemic lupus erythematosus with features of antiphospholipid or Sjogren's syndrome differ in molecular signatures and treatment perspectives
- 2019
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Ingår i: Arthritis Research & Therapy. - : BioMed Central. - 1478-6354 .- 1478-6362. ; 21
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundPrevious studies and own clinical observations of patients with systemic lupus erythematosus (SLE) suggest that SLE harbors distinct immunophenotypes. This heterogeneity might result in differences in response to treatment in different subgroups and obstruct clinical trials. Our aim was to understand how SLE subgroups may differ regarding underlying pathophysiology and characteristic biomarkers.MethodsIn a cross-sectional study, including 378 well-characterized SLE patients and 316 individually matched population controls, we defined subgroups based on the patients' autoantibody profile at inclusion. We selected a core of an antiphospholipid syndrome-like SLE (aPL+ group; positive in the lupus anticoagulant (LA) test and negative for all three of SSA (Ro52 and Ro60) and SSB antibodies) and a Sjogren's syndrome-like SLE (SSA/SSB+ group; positive for all three of SSA (Ro52 and Ro60) and SSB antibodies but negative in the LA test). We applied affinity-based proteomics, targeting 281 proteins, together with well-established clinical biomarkers and complementary immunoassays to explore the difference between the two predefined SLE subgroups.ResultsThe aPL+ group comprised 66 and the SSA/SSB+ group 63 patients. The protein with the highest prediction power (receiver operating characteristic (ROC) area under the curve=0.89) for separating the aPL+ and SSA/SSB+ SLE subgroups was integrin beta-1 (ITGB1), with higher levels present in the SSA/SSB+ subgroup. Proteins with the lowest p values comparing the two SLE subgroups were ITGB1, SLC13A3, and CERS5. These three proteins, rheumatoid factor, and immunoglobulin G (IgG) were all increased in the SSA/SSB+ subgroup. This subgroup was also characterized by a possible activation of the interferon system as measured by high KRT7, TYK2, and ETV7 in plasma. In the aPL+ subgroup, complement activation was more pronounced together with several biomarkers associated with systemic inflammation (fibrinogen, -1 antitrypsin, neutrophils, and triglycerides).ConclusionsOur observations indicate underlying pathogenic differences between the SSA/SSB+ and the aPL+ SLE subgroups, suggesting that the SSA/SSB+ subgroup may benefit from IFN-blocking therapies while the aPL+ subgroup is more likely to have an effect from drugs targeting the complement system. Stratifying SLE patients based on an autoantibody profile could be a way forward to understand underlying pathophysiology and to improve selection of patients for clinical trials of targeted treatments.
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