Differences in T cell subsets between men and women with idiopathic thrombocytopenic purpura

Idiopathic thrombocytopenic purpura (ITP) is an autoimmune disorder, occurring predominantly in women. We studied by flow cytofluorimetry the T cell subsets in men and women with ITP and compared them with healthy sex-matched volunteers. In healthy controls, women were found to have higher proportions of T helper/inducer (T(h/i)) and lower T suppressor/cytotoxic (T(s/c)) lymphocytes and consequently higher T(h/i):T(s/c) ratios than men. Accordingly, in clinical surveys, patients and controls should be matched for sex for proper comparisons. In patients with ITP in its active phase, an imbalance in T cell subsets was found in both sexes. The perturbation was more severe in women who had a marked decrease in number and proportion of T(h/i) lymphocytes and an increase in the proportion of T(s/c) lymphocytes, whereas in men only, the proportion of T(h/i) lymphocytes was decreased. When patients with active disease were compared to those with ITP in remission, the decrease in T(h/i) subsets still persisted in both sexes but the T(s/c) subset in women had returned to normal proportions. Therefore, the immune imbalance in ITP is more marked in women than men; imbalances in both T(h/i) and T(s/c) are present in women while T(s/c) appears not to be involved in men.