Investigations on red cell size distribution histograms in subjects treated by maintenance haemodialysis.

In forty-nine subjects on maintenance haemodialysis quantitative information with respect to changes in the erythron was derived from the red blood cell size distribution histogram. Increased values for the fraction of microcytes were observed in seventeen subjects, whereas in three subjects increased fractions of macrocytes were established. Both fractions were found to be increased simultaneously in only one subject. In the case of normal mean corpuscular volume (MCV) values, the fractions of microcytes were shown to be increased in four male and three female subjects. In contrast, MCV values were increased in four male subjects while the fractions of macrocytes did not exceed the reference range. Several causes which may give rise to abnormalities in red blood cell size distribution histograms in subjects treated by haemodialysis are discussed. From the interpretation of results for serum ferritin concentration, serum iron concentration, total iron binding capacity, and iron saturation percentage it is difficult to establish unequivocally whether the iron supply to the patient is appropriate.