Detection of haemoglobins with abnormal oxygen affinity by single blood gas analysis and 2,3-diphosphoglycerate measurement.
The aim is to determine if a single measurement of blood 2,3-diphosphoglycerate combined with gas analysis (pH, PCO2, PO2 and saturation) can identify the cause of an altered blood-oxygen affinity: the presence of an abnormal haemoglobin or a red cell disorder. The population (n=94) was divided into healthy controls (A, n=14), carriers of red cell disorders (B, n=72) and carriers of high oxygen affinity haemoglobins (C, n=8). Those variables were measured both in samples equilibrated at selected PCO2 and PO2 and in venous blood. In the univariable approach applied to equilibrated samples, we correctly identified C subjects in 93.6% or 96.8% of the cases depending on the selected variable, the standard P50 (PO2 at which 50% of haemoglobin is oxygenated) or a composite variable calculated from the above measurements. After introducing the haemoglobin concentration as a further discriminating variable, the A and B subjects were correctly identified in 91.9% or 94.2% of the cases, respectively. These figures become 93.0% or 86.1%, and 93.7% or 94.9% of the cases when using direct readings from venous blood, thereby avoiding the blood equilibration step. This test is feasible also in blood samples stored at 4 degrees C for 48 h, or at room temperature for 8 h.
Guerrini
G
G
Servizio di Fisiopatologia Toracica, Villa D'Ognissanti, Ospedale di Careggi, Firenze, Italy.
Morabito
A
A
Samaja
M
M
D019794:2,3-Diphosphoglycerate / Q000097:blood*; D000328:Adult; D001784:Blood Gas Analysis; D005260:Female; D006454:Hemoglobins / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000378:metabolism*; D011485:Protein Binding
D006454:Hemoglobins; D019794:2,3-Diphosphoglycerate; D010100:Oxygen