High interleukin-10 production in first-degree relatives of patients with generalized but not cutaneous lupus erythematosus

Background: Preclinical research suggests that interleukin-10 (IL-10) is as sociated with susceptibility to and severity of systemic lupus erythematosu s, Chronic cutaneous lupus erythematosus is thought to be immunogenetically different from systemic lupus erythematosus, We hypothesized that high inn ate production of IL-10 underlies systemic but not chronic cutaneous lupus erythematosus, Methods: IL-10 production was determined after endotoxin stimulation of who le-blood samples. In whole-blood samples, disease activity and medication i nfluence the IL-10 production in patients. Therefore, healthy first-degree relatives of patients were evaluated. One hundred sixty-six first-degree re latives of patients with systemic lupus, 50 first-degree relatives of patie nts with chronic cutaneous lupus, and 133 control persons were studied. Inn ate IL-10 production of the patient was estimated as the mean IL-10 product ion of tbe unaffected relatives. Polymorphisms located - 1082, -819, and -5 92 base pairs relative to the IL-10 gene were typed by allele-specific olig ohybridization of polymerase chain reaction-amplified DNA fragments, Results: IL-10 production was higher in the families of patients with syste mic lupus than in the control families (1517+/-94 vs 1180+/-59 pg/mL; P=0.0 03). IL-10 production in the families of patients with chronic cutaneous lu pus was similar to that in control families (1216+/-82 vs 1180+/-59 pg/ml; P=0.74). IL-10 production was also similar in families of patients with sev ere compared with nonsevere systemic lupus (P=1.0). The frequency of -1082/ -819/-592 haplotypes GCC, ACC, and ATA was similar among patients and compa red with the control persons (P=0.29). Conclusions: High innate IL-10 production underlies susceptibility for syst emic lupus erythematosus but not the severity of the disease. It is not rel ated to chronic cutaneous lupus erythematosus.