Rheological properties of red cells in haemoglobin Köln disease.

The rheological properties of erythrocytes of four patients with haemoglobin Köln (Hb Köln) disease were studied. Filtration of erythrocytes through polycarbonate sieves with a pore diameter of 5 mum and viscosity measurements of erythrocytes suspensions with a PCV of 80% were carried out. The rheological properties of erythrocytes of two of the patients were severely altered. In both patients an increased haemoglobin attachment to erythrocyte membranes resulting in a decreased filtration rate of erythrocytes was found. One of these cases had been splenectomized some years before. About half of the erythrocytes of this patient contained large Heinz bodies. Erythrocytes of this patient showed a decreased filtration rate and an increased viscosity. Moreover, erythrocytes of healthy adults containing Heinz bodies after incubation with acetylphenylhydrazine showed a decreased filtration rate as well as an increased viscosity. Membranes of erythrocytes of the other patients contained haemoglobin in an amount within the normal range of haemoglobin content of membranes of healthy adults. Erythrocytes of these patients showed normal rheological properties. The haemolytic process in these patients was only mild. We suggest that the amount of total haemoglobin attached to the erythrocyte membrane corresponds to the percentage of the unstable Hb Köln present in the erythrocytes of the particular patient.