Lactate Dehydrogenase Isoenzymes in Thrombocytes in Various Diseases

Abstract

LDH isoenzymes in thrombocytes from 41 healthy subjects and 85 patients suffering from various diseases combined with changes in platelet function were studied. The isoenzymes were separated by disc acrylamide electrophoresis. In normal thrombocytes LDH 3 constituted around 41 per cent, LDH 2 around 32 per cent, LDH 1 around 12 per cent and LDH 4 around 14 per cent of the total amount, whereas only very little LDH 5 was found. The results have been evaluated statistically. No differences were found between younger and older healthy persons. In patients with hepatic cirrhosis and polycythaemia vera an increase in ratio between H and M units (increase in T‐values) was demonstrated. Significant lower T‐values were found in patients with cancer and acute phlebothrombosis. No relationship between isoenzyme parameters of thrombocytes and serum was found.

Lactate dehydrogenase is elevated in immune thrombocytopenia and inversely correlates with platelet count

“…In addition, LDH isozyme testing may be a useful diagnostic test for ITP. Platelets have a specific LDH isozyme signature (Hule, ; Knudsen & Gormsen, ; Schneider et al , ), so specific patterns may be detectable in ITP patient plasma. This is an ideal topic for further investigation.…”

LDH Activity and Isoenzymes in Platelets: Relation to Thrombopoietic Activity in Man and Rats

“…The previously demonstrated LDH (lactic acid dehydrogenase) ismmyme shifts in human platelets in various clinical states (Knudsen & Gormsen 1968) do not appear to take place during the lifetime of the platelets as assumed previously (Knudsen 1971 a), as extreme platelet populations presumably representing young and old platelets (McDonald et a1 1964, Karpatkin 1969a/b, Garg et al 1971, Karpatkin 1971 have identical isoenzyme parameters (Knudsen 1971 b). Therefore, the shifts demonstrated in the platelets must be assumed to take place at megakaryocyte or precursor level.…”

“…The previously demonstrated (Knudsen & Gormsen 1968, Knudsen 1971a) M shifts in a number of conditions, such as metastasizing cancer, acute phlebothrombosis, posthaemorrhage, and postoperatively, often accompanied by reactive thrombocytosis (Levin & Conley 1964, Breslow et al 1968, must be due to altered enzyme kinetics in the cytoplasm of the megakaryocytes or their precursors and should presumably be correlated to increased activity of the platelet-producing system. However, the M shift is not related merely to the thrombopoietic activity.…”

“…For preparation of platelet homogenate by differentiated centrifugation, freeze-thawing, and determination of log HIM and LDH/platelet, cf. below and/or Knudsen & Gormsen 1968. Rat experimenfs. 25 male Sprague-Dawley rats of the same strain (State Serum Institute, Copenhagen), weighing 300 _+ 25 g were used.…”

Subbands of Lactate Dehydrogenase Isoenzymes in Human Thrombocytes

“…Human platelets especially contain LDH 3 (HHMM) and LDH 2 (HHHM), less LDH 1 (HHHH) and LDH 4 (HMMM) and little LDH 5 (MMMM) (Hule 1966, Knudsen & Gormsen 1968, Schneider et al 1968). Platelets from patients suffering from various diseases might exhibit a shift in relative amounts of H and M subunits (Knudsen & Gormsen 1968).…”