Association between tnf -308a and systemic lupus erythematosus in relation to hla-dr3 and six microsatellite markers on the short arm of chromosome vi

MW Van der Linden, A Van der Slik, E Pieterman, E Zanelli, MJ Giphart, FC Breedveld, RG Westendorp, TW HuizingaClinical Epidemiology Immunohaematology and Blood Transfusion Rheumatology General Internal Medicine, Leiden University Medical Centre, Leiden, NetherlandsBackground Allelic imbalance at polymorphic loci within the human HLA-DRB1 and TNF genes has been observed in association with increased susceptibility to systemic lupus erythematosus. Objectives We investigated whether the association of HLA-DRB1*0301 (HLA-DR3) and TNF-308A with SLE could be attributed to linkage to six polymorphic microsatellites between HLA-DRB1 and HLA-C. Methods Ninety-one consecutive Caucasian patients with SLE and 253 controls (organ donors) were typed for HLA-DRB1, D6S1014, D6S273, TNFa, MIB, C-1–2–5 and C-1–3–2 and for TNF promoter polymorphisms. Independent contribution of alleles to disease susceptibility was estimated by crosstabulation and multivariate regression. Results Carriership of TNF-308A was associated with susceptibility to SLE (odds ratio [95% confidence interval], 3.70 [2.24–6.11]). This remained present after stratification on carriership of HLA-DR3 (pooled odds ratio, 2.53 [1.37–4.70]). Stratification further revealed a possible association of carriership of C-1–2–5*192 with protection from SLE beyond the effects of HLA-DR3 and TNF-308A. Gene dose effect was observed for -308A only (homozygotes, 7.75 [3.01–20.0], heterozygotes, 3.15 [1.85–5.37]). In multivariate analysis, the association between HLA-DR3, TNF-308A, and C-1–2–5*192 remained independently associated with susceptibility to SLE (2.58 [1.29–5.18], 2.76 [1.43–5.31], and 0.26 [0.10–0.66], respectively). Conclusion An association of carriership of TNF-308A with susceptibility to SLE can not be attributed to linkage to HLA-DR3, nor to other polymorphic markers in the vicinity of the TNF gene. Further loci that are independently associated with SLE might be located in the vicinity of marker C-1–2–5. Citation: Ann Rheum Dis, volume 60, supplement 1, year 2001, page A43Session: Genomics, genetics basis of disease and HLA/T cell recognition