Abstracts (complete list) - Wissenschaft Online

Ulrich Salzer, Jennifer Birmelin, Chiara Bacchelli, Torsten Witte, Ulrike Buchegger-
Podbielski, Rita Rzepka, H Bobby Gaspar, Reinhold E Schmidt, Inga Melchers§, Bodo
Grimbacher§
Sequence analysis of TNFRSF13b/TACI in patients with
Systemic Lupus Erythematosus
Background: BAFF and APRIL and their receptors BAFFR, BCMA and TACI are involved in
the regulation of B cell homeostasis and differentiation. BAFF overexpression leads to
systemic lupus erythematosus (SLE) like symptoms 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.
Methods/Results: Based on our recent finding that TACI is mutated in patients with
common variable immunodeficiency, of whom more than 30% suffer from autoimmune
conditions, we analyzed TACI by heteroduplex analysis and subsequent sequencing in
humans with SLE.
Sequence analysis of TNFRSF13b/TACI in 119 unrelated SLE patients revealed four
variants: R20C in exon 1, R72H in exon3, the silent variation c.327 G>A in exon 3, and
A181E in exon 4.
Conclusions: No significant association with any of these variants was found, when
compared to the frequencies of the variants in a healthy control cohort. Furthermore the
mutated alleles R20C and R72H did not segregate with the SLE phenotype in familial
cases of SLE. Thus, our evaluation of the coding region of TNFRSF13b/TACI did not
reveal any deleterious or disease associated mutations.
Supported by EU SP23-CT-2005-006411; NIH/NIAID: USIDnet grant # NO1-A1-30070
(B. G.), BMBF KN Rheuma C2.12 (T.W. and R.E.S), the BMBF KN Rheumatism 01 GI
9949/C2.13 (I. M.).
§contributed equally