Erythrocyte and leucocyte enzymes in a case of paroxysmal nocturnal haemoglobinuria.

In a patient with paroxysmal nocturnal haemoglobinuria (PNH) enzymatic activities of erythrocytes and leucocytes were studied. Studies of autohaemolysis were also performed. The following erythrocytary enzymes were measured: Glucose-6-phosphate dehydrogenase (G-6-PD), pyruvate kinase (PK), glutathione reductase (GR), and acetylcholinesterase (AcChE). The following enzymes were measured in leucocytes: Adenosine deaminase, purine nucleoside phosphorylase, adenine phosphoribosyltransferase, hypoxanthine phosphoribosyltransferase and adenosine kinase. Normal activity of G-6-PD, GR and PK in erythrocytes was found. In leucocytes and lymphocytes activity of purine nucleoside phosphorylase was reduced. Auto-haemolysis in vitro was increased, which could not be compensated by addition of glucose or ATP.