DSDNA-REACTIVE, NUCLEOHISTONE-REACTIVE AND DNASE-I-REACTIVE T-LYMPHOCYTES IN PATIENTS AFFECTED BY SYSTEMIC LUPUS-ERYTHEMATOSUS - CORRELATION WITH CLINICAL-DISEASE ACTIVITY

Objective. To demonstrate the involvement of T lymphocytes reactive to autoantigens in the pathogenesis of autoimmune diseases and to analys e their clinical relevance. Methods. The frequency of T cell clones re active to double strand DNA (dsDNA), Nucleohistone (NH) complex and Dn ase I was calculated for the peripheral blood mononuclear cells (PBMC) of 15 SLE patients and 9 healthy subjects by proliferation assay. Res ults. DsDNA- and NH-specific T cell clones were found in the majority of the patients analysed (frequency ranging from 2 to 50 clones/10(7) PBMC), while their absence or very low frequency (2 clones/10(7) PBMC) was observed in the control PBMC. Their frequency significantly corre lated with decreased serum concentrations of C3 and C4 and with the sy stemic lupus erythematosus disease activity index (P = 0.03). A very l ow frequency of Dnase I-reactive T cell clones was observed in both SL E and healthy subjects. Conclusions. Our results suggest that dsDNA- a nd NH-reactive T lymphocytes may be involved in the pathogenesis of SL E and that their quantification in the peripheral blood of patients co uld be a useful tool to follow the clinical course of the disease.