Relationship of red-cell 2,3-diphosphoglycerate with anaemia, hypoxaemia and acid-base status in patients with cirrhosis of the liver.
The red-cell 2,3-diphosphoglycerate (DPG) concentration is determined in 60 patients with hepatic cirrhosis, in 33 with iron deficiency anaemia and in 86 healthy subjects. In all cases, the erythrocyte volume fraction and the haemoglobin concentration are simultaneously measured, while the cirrhotic patients undergo, at the same time, analyses of the arterial pH, pO2 and pCO2 and of the levels of inorganic phosphate, bicarbonate and lactate in their venous blood. In the 60 cirrhotic patients the red-cell DPG concentration (7.40 +/- 1.23 mmol/l) is significantly higher (P less than 0.001) than in the 86 control subjects (4.58 +/- 0.59 mmol/l) and the 33 patients with iron deficiency anaemia (5.86 +/- 1.06 mmol/l), although the level of anaemia in the latter is greater (P less than 0.001) than in the patients with liver cirrhosis. The DPG concentration found in the cirrhotic patients was far higher (P less than 0.001) than the theoretical value attributable to them by virtue of their grade of anaemia (5.21 +/- 0.95 mmol/l), which value is deduced mathematically from the equation of the regression line between haemoglobin and DPG normal in patients with iron deficiency anaemia. Anaemia, hypoxaemia and acid-base disturbances are disorders frequently associated with cirrhosis of the liver. In the present study we deduce that alkalosis, and therefore the plasma pH level, is the most important factor causing the increased DPG concentration in patients with liver cirrhosis for any level of haemoglobin, with respect to other subjects with anaemia.