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- 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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| 2. |
- Prokunina, Ludmila, et al.
(författare)
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A regulatory polymorphism in PDCD1 is associated with susceptibility to systemic lupus erythematosus in humans
- 2002
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Ingår i: Nature Genetics. - : Springer Science and Business Media LLC. - 1061-4036 .- 1546-1718. ; 32:4, s. 666-669
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Recension (övrigt vetenskapligt/konstnärligt)abstract
- Systemic lupus erythematosus (SLE, OMIM 152700) is a complex autoimmune disease that affects 0.05% of the Western population, predominantly women. A number of susceptibility loci for SLE have been suggested in different populations, but the nature of the susceptibility genes and mutations is yet to be identified. We previously reported a susceptibility locus (SLEB2) for Nordic multi-case families. Within this locus, the programmed cell death 1 gene (PDCD1, also called PD-1) was considered the strongest candidate for association with the disease. Here, we analyzed 2,510 individuals, including members of five independent sets of families as well as unrelated individuals affected with SLE, for single-nucleotide polymorphisms (SNPs) that we identified in PDCD1. We show that one intronic SNP in PDCD1 is associated with development of SLE in Europeans (found in 12% of affected individuals versus 5% of controls; P = 0.00001, r.r. (relative risk) = 2.6) and Mexicans (found in 7% of affected individuals versus 2% of controls; P = 0.0009, r.r. = 3.5). The associated allele of this SNP alters a binding site for the runt-related transcription factor 1 (RUNX1, also called AML1) located in an intronic enhancer, suggesting a mechanism through which it can contribute to the development of SLE in humans.
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