Alarcón GS et al. (2006) Time to renal disease and end-stage renal disease in PROFILE: a multiethnic lupus cohort. PLoS Med 3: e396

One of the most serious manifestations of systemic lupus erythematosus (SLE) is renal involvement, which can progress to end-stage renal disease (ESRD). To identify factors that increase the risk of renal involvement and its progression to ESRD in SLE, Alarcón et al. examined socioeconomic–demographic, clinical and genetic variables in a multiethnic SLE cohort of 1,008 patients from five US institutions.

The researchers found that, overall, Texan Hispanics and African Americans were more likely to develop renal complications of SLE, and to develop these complications more rapidly, than white Americans or Puerto Rican Hispanics. Youth, hypertension, and fulfillment of increased numbers of (nonrenal) American College of Rheumatology criteria for SLE were also associated with a reduced time to onset of renal involvement. Variables associated with progression of renal involvement to ESRD included young age, increased accrual of nonrenal damage caused by SLE and a short duration of SLE at study entry. Progression to ESRD was more likely to occur in Texan Hispanics than in other ethnic groups, and in these individuals the time to ESRD was shorter. Young age and, notably, homozygosity for the valine allele of FcγRIIIa, were independently associated with a rapid deterioration of renal involvement, toward ESRD. The investigators found no differences in the distribution of this allele across ethnic groups; hence, the ethnic disparity in the risk of progressive renal involvement in SLE patients remains to be addressed.