[Clinical significance of the determination of lactate dehydrogenase in acute leukemia and non-Hodgkin's lymphoma].

The serum concentration of LDH increases in various cancers and its increase can represent a prognostic marker of the disease and a good indicator of the tumoral mass's degree of growth. In patients with acute leukaemia, LDH can show a moderate increase only in some cases of acute non-lymphoblastic leukaemia with FAB M4 and M5 cytotype, whereas in acute lymphoblastic leukaemia LDH almost always increases, an event related to the number of white cells during remission or a relapse of the disease. In non-Hodgkin lymphomas, measurement of total LDH is not on its own a useful aid for monitoring the therapeutic response and the course of the disease. In such cases it is right to also evaluate LDH isoenzymes because they pinpoint the persistence of residual lymphomatous foci which do not affect the level of total LDH and have not clinical evidence.