Partial C4A deficiency is associated with susceptibility to systemic lupus erythematosus in black americans

✍ Scribed by Wendell A. Wilson; Myriam C. Perez; Patricia E. Armatis

• Publisher: John Wiley and Sons
• Year: 1988
• Tongue: English
• Weight: 487 KB
• Volume: 31
• Category: Article
• ISSN: 0004-3591
• DOI: 10.1002/art.1780310913

✦ Synopsis

In a study of 59 black American patients with systemic lupus erythematosus (SLE), we found that partial C4A deficiency occurred twice as frequently as in 59 control subjects (32.3% versus 15.3%; P = 0.02).

Complete C4A deficiency, however, occurred in only 1 patient and in no controls. Partial C4A deficiency is a risk factor for SLE in black, as well as in white, SLE populations studied to date. In contrast with white patients, complete C4A deficiency occurs relatively infrequently in black patients with SLE.

The fourth component of the complement system appears to have important roles in the maintenance of normal immune responses and in the pathogenesis of systemic lupus erythematosus (SLE) (14). The association of susceptibility to SLE with the presence of genetic deficiencies of C4 was first suggested by reports on persons in whom C4 was genetically absent from serum. Thirteen of the 17 subjects with this deficiency developed SLE or lupus-like disease (5). Whereas total C4 deficiency is rare, partial genetic deficiency of C4 occurs in 3040% of the general population and has also been associated with susceptibility to SLE ( 2 4 ) .

Recent studies have shown that C4 is composed

From the Department of Medicine, Louisiana State Univer-