Recombinant erythropoietin improves cognitive function in patients maintained on chronic ambulatory peritoneal...

Psychometric performance was studied in 17 patients maintained on CAPD. Nine patients treated with rHuEpo performed a battery of psychometric tests before treatment (haemoglobin mean (SD) 6.8 (0.8) g/dl) and after partial correction of anaemia (haemoglobin 9.0 (1.0) g/dl). The same battery of psychometric tests was administered to eight patients (haemoglobin 7.7 (0.7) g/dl), matched with the treatment group for age, duration of dialysis and social class, who did not receive rHuEpo. The National Adult Reading Test was used in all patients to estimate the premorbid IQ (the peak cognitive level attained before any cognitive deterioration). In the rHuEpo-treated group current IQ, measured by a short form of the Wechsler Adult Intelligence Scale--Revised, improved by a mean of 7.2 points (P < 0.01) and approached estimated premorbid levels, while in the control group an improvement by 0.3 points was not significant. Concentration and speed of information processing were assessed by the Paced Auditory Serial Addition Task and also improved in the treatment group (P < 0.05). Memory, assessed by the Rey Auditory Verbal Learning Test, tended to improve in the treatment group with amelioration of anaemia, although only the improvement in delayed recall was significant. No overall change was seen in either group in the time taken to complete the Trail Making Test (part A). These results are consistent with our earlier findings in haemodialysis patients, indicating that anaemia makes a reversible contribution to uraemic cognitive dysfunction.