Respiratory distress of hyperleukocytic granulocytic leukemias

The rapid appearance of acute respiratory distress during the course of 25 hyperleukocytic leukemias was associated with the rapid increase of the leukocytosis. The regression of the tachypnea was spectacular when treating hyperleukocytosis by exchange transfusion and chemotherapy. Blood gas studies, although blurred to some extent by in vitro blast consumption of oxygen, showed a hypoxemia with a hypo-or normocapnia. The symptoms seem to be related to the leukostasis by the mechanical obstruction of the pulmonary capillaries. This leukostasis was shown to be responsible for a septal and alveolar oedema. The high frequency of this syndrome during the course of AGL and of acute phase of CGL seems to be linked to the low deformability of the myeloblasts. In CGL at its chronic phase, CLL or even in ALL, the absence of this syndrome could be explained by the greater deformability of the circulating cells. The hyperleukocytic AGL patients which do not have this syndrome are all characterized by a stable or slowly increasing leukocytosis. Thus, this syndrome seems to characterized by hyperleukocytic granulocytic leukemias with a rapid blood leukocyte doubling rate. Treatment in such cases is an emergency.