CD4 cytopenia and occasional expansion of CD4+CD8+lymphocytes in Sjögren's syndrome.

To define whether Sjögren's syndrome (SS) patients have lymphocytopenia compared to healthy controls, and to assess which lymphocyte subset might be involved. The presence of any concurrent infection was recorded.A cohort of ten consecutive patients with SS was studied, and the results were compared with ten sex- and age-matched controls (C).In SS, a significant cytopenia of CD4+ (679 +/- 339 vs 1110 +/- 222 cells/mm3, p < 0.005) and an even more impressive decrease in the CD4+CD45 RA+ (242 +/- 154 vs 491 +/- 190 cells/mm3, p < 0.005) subset was observed. An absolute CD4 lymphocytopenia (CD4+ < 300 cells/mm3) was seen in two patients. In one patient an unusual finding was the expansion of a double positive population of CD4+CD8+ lymphocytes. No striking relationship with any particular infection was shown. A retrospective review of the absolute CD4+ cytopenia in 54 consecutive SS cases revealed a prevalence of 5.5%.Some SS patients have T lymphocytopenia which mainly affects the CD4+CD45 RA+ subset. Occasional cases with absolute CD4 lymphocytopenia may also be observed. These patients show some evidence of mild recurrent or chronic, but never severe, opportunistic infections.