Hyperleukocytic effects on skin capillary circulation in patients with leukaemia

A decrease in capillary flow due to hyperleucocytosis may cause impairment of organ perfusion in patients with leukaemia. In order to evaluate the effects of different cell types of leukaemic cell origin on skin capillary circulation we have studied patients with (a) chronic lymphocytic leukaemia (CLL) (n = 6) and (b) acute non-lymphocytic leukaemia (ANLL) (n = 6) or chronic granulocytic leukaemia (CGL) (n = 5). Capillary blood cell velocity (CBV) in fingernail-fold capillaries was measured by videophotometric capillaroscopy. After a 1-min arterial occlusion at the finger base, the post-occlusive reactive hyperaemia was evaluated by measuring the peak (p) CBV and the time to pCBV. In patients with ANLL/GGL, both resting CBV and pCBV were lower than in healthy control subjects. In the CLL patients these values were not significantly different compared to controls. In a few patients the time to pCBV was markedly prolonged. Symptoms attributable to hyperviscosity were more common in patients with ANLL/CGL and low CBV values. It is suggested that the cell size of leucocytes may be an important factor in the development of hyperviscosity syndromes and organ malperfusion in leukaemic patients.