Absence of neutral protease and alkaline phosphatase in neutrophils of a case of hairy cell leukemia.

Enzymaticaly homogeneous fractions of lymphocytes, monocytes, and neutrophils were isolated by zonal centrifugation from peripheral blood of a patient with hairy cell leukemia, or leukemic reticuloendotheliosis, LRE,(with leukopenia, neutropenia, lymphocytosis, and massive splenomegaly). To detect enzymatic deficiencies, the cells were analyzed quantitatively for six leukocytic enzymes on three occasions: 1) before splenectomy, 2) 5 days after splenectomy, and 3) 6 weeks after splenectomy. Before splenectomy, the patient's cells showed moderate deficiency of beta-glucuronidase in lymphocytes and monocytes; server to modorate deficiency of lysozyme and myeloperoxidase in monocytes and granulocytes; and complete absence of neutral protease and alkaline phosphates in neutrophils. Full restoration of neutral protease and a three-fold rise in alkaline phosphatase activities occurred in the patient's neutrophils 5 days after splenectomy. Lysozyme and myeloperoxidase returned to normal in both monocytes and neutrophils of the patient. Six weeks following splenectomy, the alkaline phosphatase activity again disappeared from patient's neutrophils, although neutral protease remained normal. The patient's lymphocytes were unresponsive to PHA and PW mitogen before splenectomy but became responsive 6 weeks postoperatively. Monocytic transfomation into macrophges was supressed before and after splenectomy. The findings indicate that developmenally, in lymphocytic leukemia, a biochemical defect involves the patient's monocytes and neutrophils much more severely than it affects the leukemic lymphocytes. Functionally, the results partly explain the susceptibility of LRE patients to microbial infections.