An improved acidified glycerol lysis test (AGLT) used to detect spherocytes in pregnancy.

The acidified glycerol lysis test (Zanella et al, 1980) had proved unreliable in our hands. We now report the test to be stable and reliable when conducted at 37 degrees C rather than at ambient laboratory temperature as used by earlier workers. With this modification, blood samples were tested from 167 pregnant subjects. Forty-eight were less than 26 weeks pregnant and gave normal AGLT values (T50 greater than 1800 s) while of 119 more than 26 weeks pregnant 57 (48%) gave shortened T50 values indicative of the presence of spherocytes.

Red-cell calcium in patients with renal failure.

The red-cell calcium concentration, measured by atomic absorption spectrophotometry, was found to be significantly higher in patients with end-stage renal failure than in healthy volunteers. This provides one possible explanation for some of the abnormalities of red-cell metabolism known to occur in uraemia.

Red-cell metabolism in patients with iron deficiency.

18 components of metabolism were determined in the red cells of iron-deficient patients and data were expressed per 10(12) red cells to avoid the complicating effects of hypochromia and microcytosis. Glucose consumption, AMP and ATP, glycolytic intermediates except 2,3-bisphosphoglycerate (2,3-DPG) and phosphoenolpyruvate (PEP), red-cell Na+ and the net passive leakage of Na+ and K+ at 4 degrees C were all normal. Creatine, 6-phospho-D-gluconate: NADP oxidoreductase (6PGD) activity and fresh red-cell K+ were raised, suggestive of a young cell population. However, ATP: D-fructose-6-phosphate 1-phosphotransferase (PFK) activity and ADP were low. An elevated 2,3-DPG level was attributable to the anaemia present but the somewhat raised PEP level is unexplained. It is concluded that red cells in iron deficiency show some characteristics of a young cell population; in other respects they appear normal, but in containing a low PFK activity they are abnormal.

Correction of anaemia following renal transplantation: serial changes in serum immunoreactive erythropoietin, absolute reticulocyte count and red-cell creatine levels.

Improvement of erythropoiesis following successful human renal transplantation in eight patients was monitored by sequential measurements of haemoglobin, red-cell creatine, absolute reticulocyte count and estimates of serum immunoreactive erythropoietin (siEp). SiEp increased in five patients after transplant, in three cases almost immediately after a return to normal of plasma creatinine. The increase in siEp was followed by a rise in the absolute reticulocyte count and red-cell creatine and finally by an increase in the haemoglobin level. As the haemoglobin approached normal levels a decline in the absolute reticulocyte count preceded a fall in siEp levels. Red-cell creatine also fell, though more gradually than the reticulocyte count. Acute graft rejection (in two patients) was associated with a fall in siEp. Chronic rejection (in one patient) was associated with persistent increases in siEp, reticulocyte count and red-cell creatine; this patient subsequently developed erythrocytosis.

Rapid correction of red-cell nucleotide abnormalities following successful renal transplantation.

Erythrocyte levels of 5' mono-, di- and triphosphates of adenosine, inosine and guanosine, together with NAD+ (H) and NADP+ (H) were measured before and serially after renal transplantation. The high levels of ATP and guanosine triphosphate (GTP) fell to normal within 3 d of achieving a normal plasma creatinine. The decline in ATP and GTP levels paralleled the fall in plasma creatinine. Acute graft rejection was accompanied by a rise in ATP and GTP, both of which returned rapidly to normal with resolution of the rejection episode. Radiolabelling of red cells confirmed that the metabolism of the existing red-cell population was corrected so that observed changes in nucleotide concentrations were not due to a new cohort of cells.

Viscosity and iron deficiency in treated polycythaemia.

An in vitro study of the effect of red-cell changes due to iron deficiency on whole-blood viscosity has been made on samples from patients with polycythaemia treated by venesection. When the PCV of the samples was adjusted to a standard value of 0.45, whole-blood viscosity was unrelated to decreasing MCH. In contrast, when samples were adjusted to a standard Hb concentration of 14 g/dl, whole-blood viscosity rose exponentially with decreasing MCH. This increase in whole-blood viscosity was shown to be a function of the increasing PCV that accompanies the falling MCH at this standard Hb value. It is suggested that in polycythaemia not due to hypoxia, hyperviscosity can be satisfactorily corrected by venesection controlled by monitoring the PCV alone. Other consideration may apply in hypoxic polycythaemia and these are discussed.

Leucocyte ATP and renal failure.

1. We have measured adenosine 5'-triphosphate (ATP) levels in isolated leucocyte suspensions from patients with renal failure. 2. Leucocyte ATP is reduced in these patients, unlike erythrocyte ATP which is known to be elevated in uraemia. 3. The relevance of reduced leucocyte ATP to the abnormalities of cation transport and cell function which occur in uraemia is discussed.

Defibrination of normal human blood in vitro: a method giving a high recovery of untraumatized cells.

A new automatic apparatus is described for the defibrination of blood in vitro at laboratory temperature which results in only small (less than 10%) losses of white cells. Freshly-drawn blood is mixed smoothly at high speed (greater than 1200 rpm) and fibrin is removed rapidly as formed. The apparatus is designed to produce minimum mechanical trauma to the blood. Subsequent in vitro incubation of red cells, granulocytes and lymphocytes demonostrated their viability to be comparable with cells obtained by other methods of defibrination.

Anaerobic glycolysis in normal human erythrocytes incubated in vitro with sodium salicylate.

1. Some effects of sodium salicylate upon anaerobic glycolysis have been studied in normal human erythrocytes incubated for up to 6 h at 37 degrees C in autologous sera. 2. Both glucose consumption and lactate production were stimulated by concentrations of salicylate up to 60 mmol/l but at the highest concentration used (90 mmol/l) an initial stimulus was followed by inhibition of glycolysis. 3. Losses occurred of adenosine 5'-triphosphate (ATP), adenosine 5'-diphosphate (ADP) and adenosine 5'-phosphate(AMP)at higher concentrations of salicylate and there was a concomitant increase of inorganic phosphate. 4. Other phosphate esters underwent concentration changes at higher concentrations of salicylate that reflected inadequate concentrations of ATP for glycolysis. 5. The rates of sodium efflux from, and potassium influx into, erythrocytes were unaffected by the presence of salicylate at concentrations sufficient to stimulate glycolysis.

The effect of o-salicylate upon pentose phosphate pathway activity in normal and G6PD-deficient red cells.

The effect of the major metabolite of aspirin, namely salicylic acid, upon the pentose phosphate pathway (PPP) of normal and G6PD-deficient red cells has been studied. Salicylic acid was shown to inhibit this pathway in proportion to the amount present. At any concentration of this substance there was greater inhibition of the PPP in G6PD-deficient than in normal red cells.