Immunoregulatory defects in patients with systemic lupus erythematosus in clinical remission

Abstract

Little is known about the immune system of patients with systemic lupus erythematosus(SLE) during periods of silent disease. To address this issue we analysed lymphoid populations and cytokine productionof mononuclearcells obtained from SLE patients in remission.We studied 43 patients with inactive disease, 10 with active disease and 30 controls. Remission was defined as at least 1 year during which lack of clinical disease activity permitted withdrawal of all treatment. Remission length ranged from 1 to 30 years. Flow cytometry and ELISA were used to study lymphoid populations (CD4, CD8 and CD19) and cytokineproduction(IL-2, 4, 10, 12 and 18). Patientswith short remission periods (up to 15 years) exhibited an increased percentage of B cells; production of IL-2, IL-10 and IL-12 was decreased;productionof IL-18 was increased. Interestingly, patients from groups with long time of inactive disease had corrected most alterations, but had an impaired IL-18 expression. IL-12 production correlated strongly with the length of the remission period (r 0.7565). The immune system of patients with inactive lupus has partially corrected the disturbances present during disease activity.This is accomplishedgradually, sometimes until counter-regulatoryalterationsare developed. This may allow patients to remain without disease activity.