Association of the X-chromosomal genes TIMP1 and IL9R with rheumatoid arthritis.

Objective: Rheumatoid arthritis (RA) is an inflammatory joint disease with features of an autoimmune disease with female predominance. Candidate genes located on the X-chromosome were selected for a family trio-based association study.

Methods: A total of 1452 individuals belonging to 3 different sample sets were genotyped for 16 single-nucleotide polymorphisms (SNP) in 7 genes.

Sequence analysis of TNFRSF13b, encoding TACI, in patients with systemic lupus erythematosus.

B cell activating factor belonging to the TNF family (BAFF) and a proliferation inducing ligand (APRIL), and their receptors BAFF receptor (BAFFR), B cell maturation antigen (BCMA), and transmembrane activator and CAML interactor (TACI) are involved in the regulation of B cell homeostasis and differentiation. BAFF overexpression leads to systemic lupus erythematosus (SLE) in mice and elevated BAFF levels have been observed in human SLE and mouse models for SLE. Furthermore, genetic inactivation of TACI in mice results in a SLE-like phenotype.