Adenine nucleotide concentrations in patients with erythrocyte autoantibodies.

Erythrocyte adenine nucleotide concentrations were measured in 154 patients with erythrocyte autoantibodies and 811 normal subjects using a luciferin-luciferase bioluminescent assay. The patients were initially divided into haemolysing and non-haemolysing groups. Red cell adenosine triphosphate (ATP) concentrations were significantly raised in the 96 patients with active haemolysis compared with the normal subjects and with the 58 patients in the non-haemolysing group. Although the patients categorised as non-haemolysing had higher ATP values than the normal subjects, this was because several patients had the anaemia of chronic disorders, which is associated with a shortened red cell life. Measurement of red cell ATP was a useful indicator of mean erythrocyte age and a raised value in patients with erythrocyte autoantibodies reflected active haemolysis.