Homozygous C2 deficiency, lupus erythematosus, and ANTI-Ro (SSA) antibodies

✍ Scribed by Thomas T. Provost; Frank C. Arnett; Morris Reichlin

• Publisher: John Wiley and Sons
• Year: 1983
• Tongue: English
• Weight: 290 KB
• Volume: 26
• Category: Article
• ISSN: 0004-3591
• DOI: 10.1002/art.1780261017

✦ Synopsis

C2 deficiency (C2d) is the most common hereditary human complement component defect (1). The prevalence of homozygous C2d has been estimated from 1 in 10,000 to 1 in 40,000 people, while heterozygous C2d is found in 1-2% (2,3). The gene(s) coding for the synthesis of this protein are within the major histocompatibility complex, and C2d usually segregates in families bearing the HLA-A25, B18, Dw2 haplotype (4-6). In addition, there are many reports strongly suggesting increased prevalence of various connective tissue diseases, especially systemic lupus erythematosus (SLE), among heterozygous and homozygous C2d subjects (1-6). Approximately one-third of the reported homozygous C2d patients have discoid (cutaneous) and/or a systemic lupus erythematosuslike (SLE-like) disease (1,7).

Cutaneous lesions are prominent among the homozygous C2d SLE-like patients (1,8). Some of these patients have demonstrated widespread annular photosensitive lesions reminiscent of those in the recently described subacute cutaneous lupus erythe-