| 1. |
- Kristjánsdóttir, Helga, 1966-, et al.
(författare)
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Association of three systemic lupus erythematosus susceptibility factors, PD-1.3A, C4AQ0, and low levels of mannan-binding lectin, with autoimmune manifestations in Icelandic multicase systemic lupus erythematosus families
- 2008
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Ingår i: Arthritis and Rheumatism. - : Wiley. - 0004-3591 .- 1529-0131. ; 58:12, s. 3865-3872
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To study autoimmune diseases and autoantibodies in Icelandic multicase systemic lupus erythematosus (SLE) families and to determine the association of 3 SLE susceptibility factors, PD-1.3A, C4AQ0, and low levels of mannan-binding lectin (MBL), with autoimmune disease in this population. Methods: Eight SLE multicase families were studied, comprising a total of 124 family members (23 patients with SLE and 101 relatives). The diagnosis of an autoimmune disease was established and autoantibodies were measured in each family. In addition, PD-1.3A alleles were genotyped, and C4AQ0 allotypes were established by electrophoresis and haplotype analysis. Low levels of MBL were determined using enzyme-linked immunosorbent assay and variant-allele genotyping. Results: In the SLE multicase families there was a high frequency of other autoimmune diseases (32.2%) and a high frequency of autoantibodies (53.2%). Of all family members, 59.7% were determined to have SLE, other autoimmune diseases, antinuclear antibodies, and/or other autoantibodies. The families showed genetic heterogeneity for PD-1.3A, C4AQ0, and low MBL levels; the frequency of each factor ranged from 0% to 85%. The frequencies of PD-1.3A and C4AQ0 were significantly increased in patients with SLE, relatives with other autoimmune diseases, and non-autoimmune disease relatives compared with controls. In the 7 families whose members had low levels of MBL, this factor was significantly associated with SLE, but the frequency of low MBL was decreased in relatives with other autoimmune diseases as compared with non-autoimmune disease relatives and controls. There were indications of an additive effect, and 91% of patients with SLE, 78% of relatives with other autoimmune diseases, and 75% of non-autoimmune disease relatives carried at least 1 of the 3 factors. Conclusion: These results demonstrate a high frequency of autoimmune diseases and autoantibodies in SLE multicase families. PD-1.3A and C4AQ0 are part of a predisposing genetic background. Other genetic and/or environmental factors are necessary for disease expression, demonstrated by a high frequency of PD-1.3A and C4AQ0 in non-autoimmune disease relatives. Low MBL levels may be one such contributing factor. The results of this study provide an example of epistatic genetic effects and overlapping genetics in autoimmune diseases.
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| 2. |
- 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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| 3. |
- Kristjánsdóttir, Helga, 1966-
(författare)
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The PD-1 pathway and the complement system in systemic lupus erythematosus
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Autoimmune diseases occur in up to 3-5% of the general population and represent a diverse collection of diseases with regards to clinical manifestations. The unifying factor of autoimmune diseases is tissue and organ damage as a result of an immune response mounted against self-antigens. Systemic lupus erythematosus (SLE) is considered a prototype of human systemic autoimmune diseases. The etiology of SLE is as yet largely unknown, but both epidemiological and genetic data suggest an interplay between numerous and varying genetic and environmental factors. There is compelling evidence for a strong genetic component in SLE. The disease has a high λsibs value and familial clustering is apparent. Multiple susceptibility loci have been identified, some of which are syntenic between humans and mice and some of which overlap with other autoimmune diseases. This thesis is based on analysis of Icelandic multicase SLE families and Swedish SLE patients. Paper I is a study of the association of C4A protein deficiency (C4AQ0) with SLE in the multicase families and shows a significantly increased frequency of C4AQ0 in the families. The genetic basis for C4AQ0 varies and C4AQ0 is found on different MHC haplotypes, pointing to C4AQ0 as an independent risk factor for SLE. Paper II describes the association of low MBL serum levels with SLE in the families and identifies low MBL as risk factor for SLE in families that carry the defect. Low MBL was furthermore found to mediate an additive risk when found in combination with C4AQ0. In paper III cellular expression the PD-1 co-inhibitory receptor on T cells was studied. A polymorphism in the PDCD1 gene, PD-1.3A was previously associated with SLE in the multicase families. The polymorphism is thought to disrupt expression of the gene and may lead to decreased expression of the PD-1 receptor. The study demonstrates lower PD-1 expression in SLE patients and relatives in correlation to the PD-1.3A genotype. Paper IV is a compiled analysis of the SLE families, including PD-1.3A, C4AQ0, low MBL, autoimmune diseases and autoantibody profiles. The study demonstrates clustering of different autoimmune diseases and autoantibodies in families that are heterogenic with regards to the genetic susceptibility factors, PD-1.3A, C4AQ0 and low MBL.
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| 4. |
- Petri, Michelle, et al.
(författare)
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Systemic lupus international collaborating clinics renal activity/response exercise - Development of a renal activity score and renal response index
- 2008
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Ingår i: Arthritis and Rheumatism. - : Wiley. - 1529-0131 .- 0004-3591. ; 58:6, s. 1784-1788
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Tidskriftsartikel (refereegranskat)abstract
- Objective. To develop a measure of renal activity in systemic lupus erythematosus and use it to develop a renal response index. Methods. Abstracted data from the medical records of 215 patients with lupus nephritis were sent to 8 nephrologists and 29 rheumatologists for rating. Seven nephrologists and 22 rheumatologists completed the ratings. Each physician rated each patient visit with respect to renal disease activity (none, mild, moderate, or severe). Using the most commonly selected rating for each patient as the gold standard, stepwise regression modeling was performed to identify the variables most related to renal disease activity, and these variables were then used to create an activity score. This activity score could then be applied to 2 consecutive visits to define a renal response index. Results. The renal activity score was computed as follows: proteinuria 0.5-1 gm/day (3 points), proteinuria >1-3 gm/day (5 points), proteinuria >3 gm/day (11 points), urine red blood cell count > 10/high-power field (3 points), and urine white blood cell count >10/high-power field (I point). The chance-adjusted agreement between the renal response index derived from the activity score applied to the paired visits and the plurality physician response rating was 0.69 (95% confidence interval 0.59-0.79). Conclusion. Ratings derived from this index for rating of renal response showed reasonable agreement with physician ratings in a pilot study. The index will require further refinement, testing, and validation. A data-driven approach to create renal activity and renal response indices will be useful in both clinical care and research settings.
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