Treatment of cell-mediated immunodeficiency with calf thymic hormone (T.P.I.).

Eight children, four with combined immunodeficiencies and four with isolated T cell defects were treated with TPI, a crude calf thymic extract. Assessment of response was made on clinical grounds and by monitoring of immune function (T and B cell numbers, immunoglobulin levels, PHA response and delayed cutaneous reaction to Candida antigen). One child with severe combined immunodeficiency showed marked clinical improvement together with reconstitution of T cell numbers and, surprisingly, B cell numbers and immunoglobulin production. Two further children, one with a form of combined immunodeficiency and the other with a T cell defect and extensive cutaneous herpes simplex infection, showed benefit from therapy though in the latter we could not demonstrate that this was important in clearing the virus infection. None of the other children showed any consistent improvement either clinically or on testing. We found no evidence of toxicity, allergy or other adverse effects of therapy.