Diagnostic Significance of Heterogeneous Lactic Dehydrogenases in Malignant Effusions

Abstract

THERE is no laboratory test available for the differentiation of benign effusions from malignant exudates. Wroblewski and Wroblewski¹ reported in 1958 that, in malignancy, concentration of lactic dehydrogenase is frequently higher in effusions than in the corresponding sera. Nevertheless, the diagnostic value of these determinations is restricted since in about one-third of all cases investigated the amount of the lactic dehydrogenase in serum and effusion was the same¹. Recent work on lactic dehydrogenase of tissues² and serum^3–5 indicates that this enzyme occurs in a number of molecular species which can be distinguished on account of their kinetics, antigenicity, inhibition by diphosphopyridine nucleotide analogues and electrophoretic mobility. In serum, starch block^3,4 and agar gel⁵ electrophoresis and chromatography on diethylaminoethyl (DEAE) cellulose⁶ showed the presence of at least four dehydrogenases, which are best labelled according to their electrophoretic mobility, namely, α₁, α₂, β and γ-lactic dehydrogenase. A specific increase in particular fractions has been observed in the following diseases: at in myocardial infarction^3–6, α₁ + α₂ in muscular dystrophy⁴ and γ in liver disease^5,6.