| 1. |
- Cardell, Kristina, et al.
(författare)
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Excellent response rate to a double dose of the combined hepatitis A and B vaccine in previous nonresponders to hepatitis B vaccine
- 2008
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Ingår i: Journal of Infectious Diseases. - : Oxford University Press (OUP). - 0022-1899 .- 1537-6613. ; 198:3, s. 299-304
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Hepatitis B vaccine has been shown to be highly efficient in preventing hepatitis B. However, 5%-10% of individuals fail to develop protective levels (>or=10 mIU/mL) of antibodies to hepatitis B surface antigen (anti-HBs) and are considered to be nonresponders. METHODS: A total of 48 nonresponders and 20 subjects naive to the HBV vaccine received a double dose of combined hepatitis A and B vaccine (Twinrix) at 0, 1, and 6 months. The levels of anti-HBs and antibodies to hepatitis A virus (anti-HAV) were determined before vaccination and 1 month after each dose. RESULTS: Among 44 nonresponders, protective anti-HBs levels were found in 26 (59%) after the first dose and in 42 (95%) after the third dose. Among the control subjects, the corresponding figures were 10% and 100%, respectively. All subjects seroconverted to anti-HAV. The titers of both anti-HBs and anti-HAV were lower in the previously nonresponsive subjects (P< .01). CONCLUSION: Revaccination of nonresponders to the standard hepatitis B vaccine regimen with a double dose of the combined hepatitis A and B vaccine was highly effective. This is most likely explained by the increased dose, a positive bystander effect conferred by the hepatitis A vaccine, or both.
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| 2. |
- Cardell, Kristina, 1964-, et al.
(författare)
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Hepatitis B vaccination in relatives to known non-responders : A family study
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Hepatitis B can be prevented by hepatitis B vaccine in most individuals. However about 5 –10% of all individuals fail to produce a protective antibody level to hepatitis B surface antigen(anti-HBs), after standard vaccination procedure with three vaccine doses. The mechanismsfor non-response are multi-factorial and not clearly understood. Non-response in this studywas defined as anti-HBs < 10 mIU/ml after at least 4 doses of intradermal hepatitis B vaccine.In this study we vaccinated relatives to known non-responders to hepatitis B vaccine. Thestudy subjects were chosen among relatives to non-responders with known HLA class IIhaplotypes. Recombinant hepatitis B vaccine was administered intradermally at 0, 1 and 6months. For those with anti-HBs <10 mIU/ml after three doses an additional dose was givenfollowed by new anti-HBs measurement. A total of 8 probands and 26 relatives wereincluded. Of the 26 relatives 15/26 (58%) responded to the vaccination schedule compared tothe expected 90-95%. This data therefore support the theory that genetic factors play animportant role in the antibody response to hepatitis B vaccine. The study population wasthough too small to conclude the role of specific genetic factors related to response and nonresponse.
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| 3. |
- Cardell, Kristina, 1964-, et al.
(författare)
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Intradermal hepatitis B vaccination in health care workers. Response rate and experiences from vaccination in clinical practise
- 1999
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Ingår i: Scandinavian Journal of Infectious Diseases. - : Informa UK Limited. - 0036-5548 .- 1651-1980. ; 31:2, s. 197-200
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Tidskriftsartikel (refereegranskat)abstract
- Health care workers at risk for hepatitis B virus infection are recommended for vaccination. Low-dose intradermal (i.d.) administration of vaccine has been suggested as a less expensive alternative to intramuscular (i.m.) inoculation. To evaluate the i.d. vaccination route, health care workers were included in a prospective study. The subjects were vaccinated with 0.1 ml (= 2 microg) recombinant vaccine (Engerix B, SmithKline Beecham) i.d. at 0, 1 and 6 months. Two months after the third vaccination, measurement of the anti-HBs level was conducted. An anti-HBs level > or =10 IU/l was considered protective. Those with an anti-HBs level <10 IU/l were given a fourth dose with new serological control after another 2 months. The results are based on the 1406 subjects that it was possible to evaluate. The seroconversion rate to protective anti-HBs level after 3 doses was 68% and after 3 or 4 doses 89%. Factors associated with a lower response rate were increasing age (p<0.05) and smoking (p<0.001). Sex or body mass index had no influence on the results. Vaccination technique seems to be of utmost importance when the i.d. route is used. Well instructed and experienced nurses are required and quality control with follow-up of overall seroconversion rate within each centre is needed.
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| 4. |
- Cardell, Kristina, 1964-, et al.
(författare)
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Nosocomial hepatitis C in a thoracic surgery unit; retrospective findings generating a prospective study
- 2008
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Ingår i: Journal of Hospital Infection. - : Elsevier BV. - 0195-6701 .- 1532-2939. ; 68:4, s. 322-328
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Tidskriftsartikel (refereegranskat)abstract
- We describe the transmission of hepatitis C virus (HCV) to two patients from a thoracic surgeon who was unaware of his hepatitis C infection. By partial sequencing of the non-structural 5B gene and phylogenetic analysis, the viruses from both patients were found to be closely related to genotype la strain from the surgeon. Two further hepatitis C cases were found in relation to the thoracic clinic. Their HCV sequences were related to each other but were of genotype 2b and the source of infection was never revealed. To elucidate the magnitude of the problem, we conducted a prospective study for a period of 17 months in which patients who were about to undergo thoracic surgery were asked to participate. Blood samples were drawn prior to surgery and at least four months later. The postoperative samples were then screened for anti-HCV and, if positive, the initial sample was also analysed. The only two patients (0.4%) identified were confirmed anti-HCV positive before surgery, and none out of 456 evaluable cases seroconverted to anti-HCV during the observation period. Despite the retrospectively identified cases, nosocomial hepatitis C is rare in our thoracic unit. The study points out the risk of transmission of hepatitis C from infected personnel and reiterates the need for universal precautions.
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| 5. |
- Cardell, Kristina, 1964-
(författare)
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Studies on Hepatitis B Vaccination and Factors Associated with the Vaccine Response
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Hepatitis B virus causes liver disease and up to 2 billion people have been in contact with the virus world wide. It can cause both acute and chronic disease. The routes for transmission are through blood, mother to infant at time of delivery and sexually. Chronic hepatitis B infection is a risk factor for development of liver cirrhosis and hepatocellular carcinoma. Prevention of hepatitis B virus infection is highly desirable. Since the early1980s hepatitis B vaccine has been available. It can effectively prevent the disease and has been found to be safe. The World Health Organisation, WHO, has recommended all countries to implement the vaccine in their children’s vaccination programmes and many countries have followed this recommendation. In Sweden so far the recommendation is vaccination of identified risk groups for hepatitis B. Health care workers who are at risk of having blood contact in their work is one such risk group.In a large study on health care workers who were intradermally vaccinated with the hepatitis B vaccine, 960/1406 (68.3%) developed protective levels of antibodies to HBsAg (anti-HBs; defined as >10 mIU/mL) after three doses. After administering of an additional fourth dose to non-responders the response rate was 1187/1335 (88.9%). Risk factors for non-response were smoking and age above 40 years. Also, the vaccine response rates improved during the study and a risk of giving a too small dose with intradermal administration was also identified. This suggests that intradermal administration is dependent on well trained personnel.A genetic factor which has been proposed to be associated with a non-responder status to HBV vaccination is the HLA haplotype of the host. In a study in on 69 responders and 53 non-responders the haplotypes were therefore determined. It was found that [DQB1*0602; DQA1*0102; DR15] and [DQB1*0603; DQA1*0103; DRB1*1301] were more likely to be found in responders (p<0.025 and p<0.05 respectively). In non-responders the haplotype [DQB1*0604; DQA1*0102; DRB1*1302] was found more frequently (p<0.005). This study supports that the HLA class II of the host is involved in the ability to respond to the HBV vaccination.To further test the genetic link between the HLA of the host and a non-responder status, relatives to known intradermal non-responders with known haplotypes for DQA1, DQB1 and DRB1 were vaccinated in the same way, intradermally. The response rate in the relatives was 15/26 (58%) which is lower than expected suggesting a genetic influence on the vaccine response. In this study 5/6 with the haplotype [DQB1*0604; DQA1*0102; DRB1*1302] were non-responders which is in line with the previous data that this haplotype is correlated to hepatitis B vaccine non-response.Finally, to test a strategy by which we could induce an effective anti-HBs seroconversion in non-responders we revaccinated these with the combined hepatitis A and B vaccine intramuscularly at a double dose. Already after the first revaccination dose 26/44 (60%) responded with protective antibodies compared to 2/20 (10%) in a vaccine naïve reference group, suggesting an anamnestic response. After three doses 42/44 (95%) responded in the non-responder group and 20/20 (100%) in the reference group. All participants in the study responded to the hepatitis A antigen.In conclusion these studies show that intradermal vaccine administration can be used and is effective, and that the ability to respond is influenced by several, including genetic, factors. Importantly a non-responder status to hepatitis B vaccination is not absolute, a double dose of the combined HAV and HBV vaccine effectively overcomes this non-response in most individuals.
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| 6. |
- Hedenstierna, M, et al.
(författare)
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Long-term follow-up of successful hepatitis C virus therapy : waning immune responses and disappearance of liver disease are consistent with cure.
- 2015
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Ingår i: Alimentary Pharmacology and Therapeutics. - : Wiley. - 0269-2813 .- 1365-2036. ; 41:6, s. 532-543
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: A sustained viral response (SVR) after interferon-based therapy of chronic hepatitis C virus (HCV) infection is regarded to represent a cure. Previous studies have used different markers to clarify whether an SVR truly represents a cure, but no study has combined a clinical work-up with highly sensitive HCV RNA detection, and the determination of immune responses.AIM: To determine clinical, histological, virological and immunological markers 5-20 years after SVR.METHODS: In 54 patients, liver biochemistry, histology and elastography were evaluated. Liver biopsies, plasma and peripheral blood mononuclear cells (PBMCs) were tested for minute amounts of HCV RNA. HCV-specific T-cell responses were monitored by ELISpot and pentamer staining, and humoral responses by measuring HCV nonstructural (NS)3-specific antibodies and virus neutralisation.RESULTS: Liver disease regressed significantly in all patients, and 51 were HCV RNA-negative in all tissues tested. There was an inverse association between liver disease, HCV-specific T-cell responses and HCV antibody levels with time from SVR, supporting that the virus had been cleared. The three patients, who all lacked signs of liver disease, had HCV RNA in PBMCs 5-9 years after SVR. All three had HCV-specific T cells and NS3 antibodies, but no cross-neutralising antibodies.CONCLUSIONS: Our combined data confirm that a SVR corresponds to a long-term clinical cure. The waning immune responses support the disappearance of the antigenic stimulus. Transient HCV RNA traces may be detected in some patients up to 9 years after SVR, but no marker associates this with an increased risk for liver disease.
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| 7. |
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| 8. |
- Langö-Warensjö, Anna, et al.
(författare)
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Haplotypes comprising subtypes of the DQB1*06 allele direct the antibody response after immunisation with hepatitis B surface antigen
- 1998
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Ingår i: Tissue Antigens. - : Wiley. - 0001-2815 .- 1399-0039. ; 52:4, s. 374-380
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Tidskriftsartikel (refereegranskat)abstract
- Two HLA class II haplotypes, HLA-[DQB1*0602; DQA1*0102; DR15] and HLA-[DQB1*0603; DQA1*0103; DRB1*1301] were found to be less common in 52 nonresponders compared with 68 responders, P<0.025 and P<0.05 respectively, after vaccination with hepatitis B surface antigen (HBsAg). Another haplotype, HLA-[DQB1*0604; DQA1*0102; DRB1*1302], had a significantly higher frequency in the nonresponders (P<0.005). The nonresponders and responders were nonsmoking, healthy individuals with an antibody concentration of <10 IU/l and >100 IU/l respectively. The three haplotypes comprise either of three different DQB1*06 subtypes. Two of the seven amino acids that differ between the two responder alleles DQB1*0602 and *0603 and the nonresponder allele *0604 are located in the peptide-binding groove of the DQB1 molecule. In addition to this finding, amino acid 86 in the DRB1 molecule seems to determine the response against HBsAg. DRB1*1301 and DR15 in the responder haplotypes have a Val at this position while the nonresponder haplotype has a Gly. These results suggest a role for both the DQB1*06 alleles and the DRB1 alleles *1301, *1302 and DR15 to direct either a response or a nonresponse against HBsAg. Sixteen HLA class II genotypes were found to be shared by 25 nonresponders and 32 responders. This finding of HLA-identical nonresponders and responders indicates an influence of other genetic factors in addition to the HLA system in the response to HBsAg.
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| 9. |
- Nopp, A, et al.
(författare)
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Basophil allergen threshold sensitivity : A useful approach to anti-IgE treatment efficacy evaluation
- 2006
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Ingår i: Allergy. European Journal of Allergy and Clinical Immunology. - : Wiley. - 0105-4538 .- 1398-9995. ; 61:3, s. 298-302
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Tidskriftsartikel (refereegranskat)abstract
- Background: Monitoring of the allergen sensitivity of a patient is most important for optimal patient care and a basic prerequisite for immunomodulating treatment. The objective of this study was to investigate how basophil allergen sensitivity can be applied in the monitoring of anti-immunoglobulin E (IgE) treatment. Methods: Basophils from timothy grass pollen allergic patients were, by flow cytometry, analysed for allergen threshold sensitivity (CD-sens) by measuring CD63 up-regulation on CD203c-identified basophils. The results were compared with maximal percentage CD63 up-regulation at one allergen dose (CD-max), skin prick test end-point allergen titration, (SPT-sens), nasal provocation titration tests (nasal provocation titre) and serum IgE and IgE antibody concentrations. Results: There was a significant correlation (r = 0.50, P = 0.01) between CD-sens and SPT-sens, CD-sens and the IgE antibody concentration in percentage of 'total IgE' (relative IgE antibody concentration) (r = 0.72, P < 0.001) as well as between CD-sens and nasal provocation titre (r = 0.54, P < 0.05) but, in contrast, CD-max did not correlate with any of the sensitization parameters, i.e. SPT-sens, nasal provocation titre, absolute and relative IgE antibody concentration or CD-sens. CD-sens could be used to monitor omalizumab treatment efficacy while, based on CD-max, four of seven symptom-free patients on omalizumab would have been classified as having ongoing allergy. Conclusions: CD-sens seems to be very useful for the determination of a patient's allergen sensitivity and should be evaluated for the measurement and monitoring of anti-IgE treatment efficacy. CD-max, the conventional approach to basophil allergen challenge, which mirrors cell reactivity, gives incorrect information. Copyright © Blackwell Munksgaard 2006.
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| 10. |
- Nyström, Jessica, et al.
(författare)
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Improved cell mediated immune responses after successful re-vaccination of non-responders to the hepatitis B virus surface antigen (HBsAg) vaccine using the combined hepatitis A and B vaccine
- 2008
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Ingår i: Vaccine. - : Elsevier BV. - 0264-410X .- 1873-2518. ; 26:47, s. 5967-5972
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Tidskriftsartikel (refereegranskat)abstract
- We Successfully re-vaccinated hepatitis B Virus (HBV) vaccine non-responders Using a double dose of the combined hepatitis A virus (HAV) and HBV vaccine. The hope was to improve priming of hepatitis B surface antigen (HBsAg)-specific cell mediated immune response (CMI) by an increased antigen dose and a theoretical adjuvant-effect from the local presence of a HAV-specific CMI. A few non-responders had a detectable HBsAg-specific CMI before re-vaccination. An in vitro detectable HBsAg-specific CMI was primed equally effective in non-responders (58%) as in first time vaccine recipients (68%). After the third dose a weak, albeit significant, association was observed between the magnitude of HBsAg-specific proliferation and anti-HBs levels. This regimen improves the priming of HBsAg-specific CMIs and antibodies.
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| 11. |
- Rondahl, E., et al.
(författare)
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The risk of HCV RNA contamination in serology screening instruments with a fixed needle for sample transfer
- 2014
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Ingår i: Journal of Clinical Virology. - : Elsevier BV. - 1386-6532 .- 1873-5967. ; 60:2, s. 172-173
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Tidskriftsartikel (refereegranskat)abstract
- Background: Hepatitis C diagnostics involve antibody screening and confirmation of current infection by detection of HCV RNA positivity. In screening instruments with fixed pipetting needle, there is a risk of sample carry-over contamination. Objectives: The aim of this study was to evaluate the risk of such contamination in a proposed clinical setting. Study design: In the present study, known HCV RNA positive (n= 149) and negative (n= 149) samples were analysed by anti-HCV Abbott in an Architect instrument in an alternating fashion in order to test for contamination. Results: In subsequent retesting of the previously HCV RNA-negative samples, six samples (4%) were positive by the Cobas Taqman assay with a maximum level of 33. IU/mL. The results show that there is a risk for transfer of HCV in the Architect instrument but they also show that the levels of HCV RNA observed are low. Conclusions: We conclude that complementary HCV RNA testing on samples identified as anti-HCV positive by screening can be recommended because the complementary results are reliable in the majority of cases when either HCV RNA is negative or HCV RNA is positive with a level >1000. IU/mL. In a minority of cases, with low HCV RNA after anti-HCV antibody screening, cross-contamination should be suspected and a new sample requested for HCV RNA testing. This strategy would reduce the need for obtaining a new sample from the vast majority of patients with a newly discovered HCV antibody positivity. © 2014 The Authors.
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| 12. |
- Sjöwall, Christoffer, et al.
(författare)
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High prevalence of autoantibodies to C-reactive protein in patients with chronic hepatitis C infection: association with liver fibrosis and portal inflammation
- 2012
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Ingår i: Human Immunology. - : Elsevier. - 0198-8859 .- 1879-1166. ; 73:4, s. 382-388
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Tidskriftsartikel (refereegranskat)abstract
- The presence of autoantibodies against C-reactive protein (anti-CRP) has been reported in association with autoimmunity and histopathology in chronic hepatitis C virus (HCV) infection. Resistin could play a role in the pathogenesis of hepatitis, although results on HCV infection are ambiguous. Here we retrospectively analyzed anti-CRP and resistin levels in the sera of 38 untreated and well-characterized HCV patients at the time of their first liver biopsy. HCV activity and general health were assessed by a physician at least yearly until follow-up ended. Anti-CRP and resistin were also measured in patients with autoimmune hepatitis (AIH) and nonalcoholic fatty liver disease (NAFLD). Anti-CRP antibodies were registered in all HCV patients, whereas only a few AIH (11%) and NAFLD (12%) sera were positive. Anti-CRP levels were related to histopathological severity and were highest in patients with cirrhosis at baseline. Resistin levels were similar in HCV, AIH, and NAFLD patients, but high levels of resistin were associated with early mortality in HCV patients. Neither anti-CRP nor resistin predicted a response to interferon-based therapy or cirrhosis development or was associated with liver-related mortality. We conclude that anti-CRP antibodies are frequently observed in chronic HCV infection and could be a useful marker of advanced fibrosis and portal inflammation.
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| 13. |
- Sjöwall, Christopher, et al.
(författare)
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Soluble urokinase plasminogen activator receptor levels are associated with severity of fibrosis in nonalcoholic fatty liver disease
- 2015
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Ingår i: Translational Research. - : Elsevier. - 1931-5244 .- 1878-1810. ; 165:6, s. 658-666
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Tidskriftsartikel (refereegranskat)abstract
- The identification of individuals with severe liver fibrosis among patients with chronic liver disease is of major importance when evaluating prognosis, potential risk for complications, and when deciding treatment strategies. Although percutaneous liver biopsy is still considered a "gold standard" for staging of liver fibrosis, attempts to find reliable noninvasive markers of liver fibrosis are frequent. Inflammation is essential for the progression of fibrosis. The urokinase plasminogen activator and its receptor have been associated with hepatic inflammation and fibrosis in mice. High serum concentrations of soluble urokinase plasminogen activator receptor (suPAR) are suggested to be involved in inflammation, tissue remodeling, and cancer metastasis. Here, we evaluated serum suPAR as a noninvasive test to detect liver fibrosis in 82 well-characterized patients with nonalcoholic fatty liver disease (NAFLD), and in 38 untreated patients with chronic hepatitis C virus (HCV) infection at the time of their first liver biopsy. suPAR levels were increased in chronic liver disease compared with blood donors (P < 0.001). Patients with HCV had higher suPAR concentrations than patients with NAFLD (P < 0.002). suPAR levels were associated with the severity of fibrosis, particularly in NAFLD, but did not correlate with inflammation. Regarding the performance in predicting severity of fibrosis, suPAR was essentially as good as other commonly used noninvasive fibrosis scoring systems. The results in HCV confirm previous observations. However, this is the first study to investigate suPAR as a biomarker in NAFLD, and the results indicate that suPAR may constitute a severity marker related to fibrosis and prognosis rather than reflecting inflammation.
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| 14. |
- Sundström, Mia, 1980-
(författare)
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B cell deviations and type 1 diabetes in the NOD mouse
- 2012
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Type 1 diabetes (T1D) is a chronic autoimmune disease in which the insulin producing β-cells in the pancreatic islets of Langerhans are selectively attacked by the immune system. The β-cells are destroyed resulting in a reduced or eliminated insulin production, which in turn lead to a high blood glucose level. The non-obese diabetic (NOD) mouse is the most commonly used animal model for human T1D. NOD mice develop diabetes spontaneously through a process that closely resembles the human pathogenesis. In both humans and the NOD mouse, disease is caused by a combination of genetic and environmental factors. In the NOD mouse, more than 30 insulin-dependent diabetes (Idd) loci on 15 chromosomes have been linked to disease susceptibility, however, most of the Idd-regions lack identification of a disease associated gene. B cells are required for T1D development, although the underlying mechanisms are not fully revealed. The aim of this thesis was to dissect B cell-related immune deviations in the NOD mouse, including the underlying genetics of these traits. The TACI receptor binds two ligands, i.e. the cytokines BAFF and APRIL.TACI ligation by APRIL mediates class switch, drives plasma cell differentiation and increases immunoglobulin production. In Paper I, a novel NOD-specific B cell-related trait was identified, i.e. the increased percentage of TACIhigh-expressing splenic B cells, by comparing NOD mice with non-autoimmune disease prone C57BL/6 mice. To investigate if the described TACI trait was controlled by genes linked to any Idd-region, an Idd-focused linkage analysis was performed. The TACI-trait mapped to regions on chromosome 1 and 8, more specifically to the vicinity of the Idd5.4 and Idd22. Interestingly, the linkage to Idd22 was explained by mice ≥61 days of age, suggesting a temporal genetic regulation of TACI expression possibly influenced by the ongoing autoimmune process. In Paper II, the linkage of the TACI trait to chromosome 1 and 8 was confirmed by analyzing the percentage of TACIhigh-expressing B cells in congenic NOD.C1/Idd22 mice. Moreover, the functional consequence of TACI upregulation was investigated, with the focus on plasma cell development and immunoglobulin production. NOD splenic B cells stimulated with APRIL displayed increased numbers of plasma cells and produced higher amounts of IgG and IgA compared to B cells from C57BL/6 mice. Thus, the TACI upregulation on NOD B cells possibly contribute to a B cell compartment which is more disposed to plasma cell differentiation and isotype switch. NOD mice display enhanced and prolonged immune response towards several antigens, including non-self immunoglobulins. In Paper III, the genetic factor(s) controlling the altered immune response against a BALB/c derived monoclonal antibody were dissected. Significant linkage to the Idd1/Idd24, Idd12, and Idd18.1 regions as well as to a proximal region on chromosome 2 (33.5 Mb) was detected. The linkage to Idd1/24 was verified by analyzing a set of H2-congenic NOD and C57BL/6 mice, and the linked region was narrowed down to ~8 Mb. Candidate gene analysis revealed a significant difference in the transcription of the H2-O/DO molecule. This suggests that multiple mechanisms contribute to the loss of immune response control, including an altered MHC class II peptide loading on NOD B cells. In Paper IV, a novel B cell intrinsic receptor for IgM and IgG was revealed. The receptor appeared to be more abundant in NOD mice compared to C57BL/6 mice, as the level of extramembranous IgG monomers and IgM pentamers on peripheral blood B cells from NOD mice was significantly higher compared to C57BL/6 mice. In addition, analysis of immune complex binding using IgG- or IgM-opsonized bacterial particles revealed a higher degree of binding in NOD mice compared with C57BL/6 mice. The enhanced capture of immunoglobulins and immune complexes could thus contribute to the development of T1D by altering normal B cell functions such as activation and immune complex transportation.
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| 15. |
- Thyagarajan, Radha, 1986-
(författare)
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Anomalies in humoral immunity in the NOD mouse : contribution to the progression of type 1 diabetes
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The non-obese diabetic (NOD) mouse is widely used model Type 1 diabetes (T1D), a chronic inflammatory disease characterized by destruction of the insulin producing β cells in the islets of Langerhans by immune cells. The classical symptoms include increased glucose levels in urine and blood, frequent urination and enhanced thirst. The disease has a strong genetic component and is also influenced by the environment. NOD mice develop T1D spontaneously. The disease occurs in two phases; insulitis - the infiltration of immune cells in the islets of Langerhans and overt diabetes caused by the destruction of insulin producing β cells. Several disease associated gene regions or loci [termed insulin dependent diabetes (Idd) loci] have been associated with T1D development. Although, T1D is recognized as a T cell mediated disease in both mouse and man, many studies have shown the importance of B cells in the pathogenesis of the disease. Autoantibodies appear prior to islet infiltration and several molecular and cellular events precede this beta-cell autoimmunity. Although the pathogenesis of T1D is well characterized, less is known about the environmental and immunological factors that trigger the disease.In this thesis, we studied the contribution of B cell anomalies to the skewed immune response observed in the NOD mouse. In our studies covered in the thesis we observed that NOD mice display enhanced IgE in the serum already at one week of age. In addition, upon treatment of pre-diabetic NOD mice with anti-IgE antibodies, diabetes incidence was delayed. We hypothesize that the presence of IgE in the system may be explained due to enhanced class switching. Antibody feedback however, is an essential component of the immune response and can lead to either enhanced or dampened responses. Thus, increased IgE may provide positive feedback that might sustain an immune response. We also aimed to analyze the biological consequence of this feature. In vitro stimulation of B cells by the TACI ligand APRIL resulted in enhanced plasma cell differentiation accompanied with increased class switching and IgG production. In addition, TACI+ cells were observed in NOD germinal centers facilitating increased BAFF uptake and subsequent escape of low affinity antibody producing clones. NOD mice elicited an enhanced and prolonged immune response towards T-dependent antigens such as hen-egg lysozyme (HEL). Serum HEL-specific IgG level was significantly increased and was predominantly of the IgG1 isotype. Immunofluorescence analysis of NOD spleen revealed the presence of spontaneous germinal centers which others have perceived to provide a ready niche for the entry of naïve B cells that encountered novel antigen. Adoptive transfer experiments of purified B and T cells from NOD into NOD.Rag2-/- (NOD-RAG) mice illustrated the importance of B cell intrinsic defects in the reproduction of the original phenotype as observed in NOD.
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| 16. |
- Ydreborg, Magdalena, 1974, et al.
(författare)
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Impact of IL28B-Related Single Nucleotide Polymorphisms on Liver Transient Elastography in Chronic Hepatitis C Infection
- 2013
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Ingår i: Plos One. - : Public Library of Science (PLoS). - 1932-6203. ; 8:11
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Tidskriftsartikel (refereegranskat)abstract
- Background and Aims: Recently, several genome-wide association studies have revealed that single nucleotide polymorphisms (SNPs) in proximity to IL28B predict spontaneous clearance of hepatitis C virus (HCV) infection as well as outcome following pegylated interferon and ribavirin therapy among genotype 1 infected patients. Additionally the presence of the otherwise favorable IL28B genetic variants in the context of HCV genotype 3 infection reportedly entail more pronounced liver fibrosis and steatosis. The present study aimed to evaluate the impact of IL28B SNP variability on liver stiffness as accessed by transient elastography. Methods: Seven hundred and seventy-one Swedish HCV infected patients sequentially undergoing liver stiffness measurement by means of Fibroscan (R) in the context of a real-life trial had samples available for IL28B genotyping (rs12979860) and HCV genotyping. Results: CCrs12979860 was more common among HCV genotype 2 or 3 infected treatment-naive patients than among those infected with genotype 1 (P<0.0001). Additionally CCrs12979860 among HCV genotype 3 infected patients was associated with higher liver stiffness values (P = 0.004), and higher AST to platelet ratio index (APRI; p = 0.02) as compared to carriers of the T allele. Among HCV genotype 1 infected patients, CCrs12979860 was significantly associated with higher viral load (P = 0.001), with a similar non-significant trend noted among HCV genotype 3 infected patients. Conclusion: This study confirms previous reports that the CCrs12979860 SNP is associated with more pronounced liver pathology in patients chronically infected with HCV genotype 3 as compared to genotype 1, suggesting that IL28B genetic variants differently regulates the course of HCV infection across HCV genotypes.
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