Distinct alkaline phosphatase in serum of patients with lymphatic leukemia and infectious mononucleosis.

A distinct alkaline phosphatase (phosphatase N) was demonstrated in the serum of patients with acute lymphatic leukemia, chronic lymphatic leukemia, and infectious mononucleosis. This enzyme closely resembles that extracted from the thymus of mice with lymphoma or lymphatic leukemia, both in its electro-phoretic mobility and its substrate specificity. The phosphatase N activity was related to the clinical state of patients with lymphatic leukemia and disappeared with recovery from infectious mnononucleosis.