F cells, fetal hemoglobin levels, lymphocyte subsets, and frequency of crises in sickle-cell disease in Kuwait.

Abstract

In vitro, fetal hemoglobin (Hb F) inhibits the aggregation of Hb S, and this may be clinically significant. Alterations in B and T lymphocytes seen in sickle-cell disease may be important in the immune deficit in these patients. We examined 16 patients with repeated crises (6 females and 10 males, age 9.3 +/- 3.4 years) and 15 patients with infrequent crises (9 females and 6 males, age 7.1 +/- 3.8 years) to determine the relationship between F cells, Hb F levels, lymphocyte subsets, and the frequency of crises. The proportion of CD2 and CD3 lymphocytes was significantly lower (P=0.015 and <0.0001, respectively) in both groups of patients than controls. CD4 lymphocytes were significantly lower (P = 0.018) and CD19 significantly higher (P = 0.007) than controls. CD45RO levels in both groups of patients were comparable with matched controls but significantly lower (P = 0.002) than adult values. Hb F levels in patients with and without frequent crises were comparable (P = 0.067). However, F cells in patients with infrequent crises were significantly higher than in patients with frequent crises (P<0.01). Alteration in the lymphocyte subsets did not correlate with the frequency of crisis in these patients.