Filterability in children

The filterability of total blood and erythrocytes has been investigated in 36 children from 2 to 14 years old by the filtration method developed by Reid. Red blood cells being obtained by centrifugation, were washed three times and resuspended in saline. Filterability was recorded as the filtration time of 1 ml of total blood or red cells suspension. The filtration time of total blood was: 49.10 ± 14.5 s/ml; that of resuspended cells was: 18.19 ± 6.16 s/ml. These results have been correlated with age, fibrinogen, white blood cells, glycaemia, haematocrit, and compared with the results obtained in 42 adults whose filtration times were: 33.04 ± 7.40; and red cells' time: 13.99 ± 2.95. Statistical analysis shows that the difference is very significant and not correlated with the investigated factors. Erythrocyte filterability may be influenced by still unknown factor.