Antihelper T cell autoantibody in acquired agammaglobulinemia

A patient with acquired agammaglobulinemia had an antihelper T cell factor that was identified as an immunoglobulin of the IgG class. The factor specifically bound to the TH₂^-T cell subset and, in the presence of complement, abolished the helper effect of normal T cells. The antihelper T cell antibody preceded by several years the appearance of suppressor TH₂⁺Ia⁺ T cells, at which time the clinical course rapidly deteriorated. Plasmapheresis resulted in lymphocytosis and reappearance of a functionally intact helper T cell population. It did not affect the suppressor cell. Conversely, total thymectomy resulted in a temporary disappearance of the TH₂⁺Ia⁺ suppressor cells, but did not decrease the levels of the autoantibody to helper T cells. Neither of these treatments reversed the state of agammaglobulinemia.