Abstract
Leucine aminopeptidase (LAP) activity was quantitated using leucine amide as the substrate (LA activity) and its isozyme pattern was studied in sera, peripheral leukocytes and lymph node tissue extracts from normal individuals and patients with various hematological and lymphogenous disorders. Serum LA activities in patients in transitional and blastic phases of chronic myelogenous leukemia (CML) were elevated and higher than those in chronic phase of CML. LA activities were elevated in serum from patients with T cell lymphoma and all types of malignant lymphoma except for a patient with B cell lymphocytic lymphoma in advanced stages (IVB and leukemic). Serum LA activities were also elevated in patients with benign lymphadenitis which affected exclusively the paracortical area of the lymph node. LA activities in granulocytes from patients with CML were lower than those in normal granulocytes. Blastic cells from patients with acute myeloblastic and lymphoblastic leukemias showed lower activities than any other leukocytes. In leukemic monocytes from patients with acute monocytic leukemia, the mature monocytes showed higher LA activities than the immature monocytes. Lymph node tissue extracts from patients with T cell lymphoma differed from those with B cell lymphoma in having higher LA activities. The isozyme pattern of serum with elevated LA activity always showed a higher activity in the β fraction and zymograms of leukocytes and lymph node tissue extracts from all patients except for a few patients with CML showed most of these LA activities were electrophoreticaly demonstrated in the β fraction.
Serum LA activity appeared to well reflect the progress and recovery of some hematological and lymphogenous disorders, and to provide a useful parameter for the evaluation of patients with these disorders.
