ABNORMALITIES OF LYMPHOCYTE-T SUBSETS IN SYSTEMIC-SCLEROSIS DEMONSTRATED WITH ANTI-CD45RA AND ANTI-CD29 MONOCLONAL-ANTIBODIES

T cell subpopulations were assessed by two colour flow cytometry with phycoerythrin conjugated anti-CD45RA and anti-CD29 and fluorescein conjugated anti-CD4 and anti-CD8 monoclonal antibodies, on peripheral blood lymphocytes from 12 patients with systemic sclerosis and from nine control subjects. The percentage of CD4+CD29+ cells was significantly higher in patients with systemic sclerosis than in controls (mean (SEM) 68.8 (3.1) upsilon 47.9 (4.1) respectively). CD4+CD45RA+ cells were not significantly different in patients and controls. CD8+CD29+ and CD8+CD45RA+ subpopulations were significantly higher in patients with systemic sclerosis than in controls (83.0 (3.2) upsilon 58.7 (6.8) and 80.2 (3.0) upsilon 66.9 (3.2) respectively). The increase in the percentage of CD29+ cells suggests an activation of memory cells in patients with systemic sclerosis, which may play an important part in the pathogenesis of the disease.