Cytochemistry: an aid to the diagnosis and classification of the acute leukemias

Intracytoplasmic Lysozyme in Malignant Hematologic Disorders: An Immunoperoxidase Study

Intracytoplasmic lysozynie was studied by the peroxidase antiperoxidase (PAP) and protein A-peroxidase methods in 130 cases of various myeloproliferative and lymphoproliferative disorders and 21 lymph nodes and bone marrow metastases from solid primary tumors. This marker, which can be identified in formalin or Zenker-fixed tissues, as well as in peripheral blood and bone marrow smears, proved useful to distinguish malignant myeloid and histiocytic tumors from malignant lymphoid and undifferentiated epithelial metastases. The diagnostic application of these findings are discussed.

Multienzymatic analyses of human malignant lymphomas. Correlation of enzymatic data with pathologic and ultrastructural findings in Burkitt's and lymphoblastic lymphomas

Enzyme activity measurements are of great relevance to the classification and biochemical characterization of the various types of leukemias, but they have been much less studied in solid lymphoid tumors. The authors report investigations in human lymphomas. The levels of the following enzymes were determined: terminal deoxynucleotidyl transferase (TdT), deoxyribonucleic acid polymerase alpha (DP alpha), adenosine deaminase (ADA), purine nucleoside phosphorylase (PNP), thymidine and uridine kinases (TK and UK, respectively), and thymidine phosphorylase (ThPh). Moreover, cytochemical investigations were done in the group of Burkitt's lymphoma (BL) and lymphoblastic lymphoma (LL), and ultrastructural studies were performed in seven of the nine LL of this series. These results were obtained: (1) TdT (90 cases) was highly specific for LL; eight of nine LL were positive, and all other histologic types were negative; the only TdT-, acid esterase (AcE) positive, nonconvoluted LL was probably related to TdT- normal medullary thymocytes, and had an unfavorable clinical course with resistance to a vincristine-and-prednisone-including treatment; (2) ADA (61 cases) could distinguish clearly between the high levels of LL and the low levels found in any other group of lymphomas; among LL, the highest values were found in T-cell-derived neoplasias, and the lowest value in a periodic acid-Schiff (PAS) positive, acid phosphatase negative case that showed the presence of large nucleoli at the ultrastructural analysis, a finding that is unusual for LL and possibly related to a more immature differentiation stage; (3) PNP (39 cases) values alone were not clinically relevant, but together with ADA levels, a subset of T-LL with high ADA:PNP ratio could be selected among LL; (4) DP alpha (61 cases), and TK and UK (37 cases) were found in concentrations reflecting the malignancy of the non-Hodgkin's lymphoma, and were more elevated in the high-grade malignant lymphomas; (5) ThPh (34 cases) was always elevated in Hodgkin's disease, but low in Burkitt's lymphoma and LL; thus, they had a high TK:ThPh ratio that could be useful in predicting clinical response to thymidine treatment. The authors think that taken together, multiple enzyme determinations could be useful in the characterization of human lymphomas.

Natural killing and antibody-dependent cytotoxicity by T leukaemic blasts from acute lymphoblastic leukaemia

Bone marrow T leukaemic blasts from four patients with T-cell acute lymphoblastic leukaemia (ALL) were examined as effectors in natural killing (NK) and antibody-dependent cytotoxicity (ADCC). T leukaemic blasts demonstrated both Nk (against K-562 cells as targets) and ADCC (against chicken erythrocytes (CRBC) and cells of SB cell line as targets). NK activity and ADCC (against SB cells) were comparable to NK and ADCC (against SB cells) of peripheral blood T cells from healthy controls. ADCC against CRBC by leukaemic blasts was lower than that of peripheral T cells from normal controls. Of leukaemic blasts 20-42% possessed IgG Fc receptors. This study demonstrates that T leukaemic blasts are effectors in NK and ADCC assays.