Immunological evaluation of 22 patients with acute lymphoblastic leukemia off-therapy. A longitudinal follow-up.

In 22 patients with ALL in first complete remission, who discontinued therapy after 3 years, longitudinal follow-up of immunological reconstitution was investigated by assessing serum immunoglobulin levels, number and mitogen responsiveness of B and T lymphocytes. Major modifications have been demonstrated for T cells both in terms of number and functionality, while B cells and serum immunoglobulins did not change significantly. Examining the behaviour of the patients one by one, it has been observed that recovery is often characterized by a remarkable rebound occurring from the 15th to the 18th month. Immunosuppression induced by antileukemic treatment appeared to be a transitory phenomenon, mainly limited to the first three months. Reconstitution was achieved, in almost all cases, within one year after treatment was stopped.