Pseudo-leukocytosis Associated with Cryoglobulinemia

Abstract

Pseudo-leukocytosis was found in a patient with essential cryoglobulinemia when leukocyte (WBC) counts were determined using a Model S Coulter Counter. The spurious leukocytosis was confirmed in additional patients with cryoglobulinemia and is thought to be due to particle formation between the cryoglobulin and fibrinogen. Markedly elevated leukocyte counts not confirmed by standard methods should alert the laboratory that a cryoglobulin may be present.