DYSREGULATION OF INTERLEUKIN-10 PRODUCTION IN RELATIVES OF PATIENTS WITH SYSTEMIC LUPUS-ERYTHEMATOSUS

Objective. To evaluate interleukin-10 (IL-10) production in relatives of patients with systemic lupus erythematosus (SLE). Methods. Producti on of IL-10 was evaluated in 13 families in which several members had SLE, The constitutive IL-10 production in SLE patients (n = 16) was co mpared with that in healthy members of these multiplex families (n = 7 0), in 30 SLE patients who had no relatives with SLE, and in 46 health y unrelated controls. Results. The level of IL-10 production did not d iffer between SLE patients who were members and those who were not mem bers of multiplex families (mean +/- SEM 4,384 +/- 908 pg/ml and 4,709 +/- 560 pg/ml, respectively), but was higher in both groups than in h ealthy unrelated controls (515 +/- 88 pg/ml). The healthy members of t he multiplex families constitutively produced large amounts of IL-10 ( 3,080 +/- 311 pg/ml; P < 0.001 compared with healthy unrelated control s). This high IL-10 production was independent of age and sex, and was similar in first- and second-degree relatives of SLE patients, The IL -10 was produced both by monocytes and by a subpopulation of B lymphoc ytes in SLE patients and in their relatives. Conclusion. The dysregula tion of IL-10 production previously identified in SLE patients is also present in healthy members of families with several cases of SLE, and it may contribute to the immunologic abnormalities affecting relative s of SLE patients.