Severe combined immunodeficiency with T lymphocytes retaining functional activity.

Two cases of severe combined immunodeficiency (SCID) with normal numbers of T cells are reported. Studies of T-cell subsets showed an absence of TQ1+ lymphocytes and a very low percentage of CD4+ cells in Patient 2. Functional studies of T cells from this patient showed a normal suppressor activity. Patient 1 had normal percentages of T-cell subsets and his lymphocytes showed helper and suppressor activities but to a lesser degree than normal controls. Both cases stressed the heterogeneity of SCID in which T cells could be present and retain some of their functional activities.