The phenotype of SLE associated with complete deficiency of complement isotype C4A.

Abstract

Complete deficiency of the complement C4A isotype is a known genetic risk factor for systemic lupus erythematosus (SLE). The disease phenotype of C4A-deficient patients has never been defined. Among 200 patients with SLE from five centers, 18 (9%) with C4A deficiency were identified. These individuals were compared to those who were C4A replete with regard to a series of clinical and serologic features. The only significant differences between the two groups were in the presence of renal disease (C4A deficient, 11%; C4A replete, 46%; P < 0.006) and a decrease in the serum concentrations of C3 (C4A deficient, 11%; C4A replete, 35%; P < 0.04). There was also a trend for the C4A-deficient individuals to have milder disease. In light of the tendency for C4A-deficient individuals to have lower serum concentrations of C4, it is important that such patients not be subjected to overly aggressive efforts to "normalize" their C4 levels.

• Authors: T R Welch, C Brickman, N Bishof, S Maringhini, M Rutkowski, M Frenzke, N Kantor
• Journal: Journal of clinical immunology (J Clin Immunol) Vol. 18 Issue 1 Pg. 48-51 (Jan 1998) ISSN: 0271-9142 [Print] Netherlands
• PMID: 9475353 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Complement C3
• Complement C4a

Topics

• Adult
• Alleles
• Black People (genetics)
• Complement C3 (analysis)
• Complement C4a (analysis, deficiency)
• Female
• Humans
• Lupus Erythematosus, Systemic (blood, genetics)
• Male
• Middle Aged
• Multicenter Studies as Topic
• Phenotype
• Severity of Illness Index
• White People (genetics)