[Pseudoleukocytosis in cryoglobulinemia type I].

During routine clinical and laboratory examinations of a symptom-free 54-year-old man a leukocytosis was repeatedly noted, but no cause found. 11 months later a painful spontaneously disappearing cyanosis occurred in two fingers of his right hand. Serum analysis demonstrated monoclonal type IgG-kappa immunoglobulin and an antinuclear antibody titre of 1:160. Skin biopsy suggested scleroderma. 4 months later, after exposure to cold, extensive acral haemorrhages occurred. Serum cryoglobulin concentration in serum was found to be 800 mg/dl. Comparative manual and electronic counts on warm and cooled blood identified the previously diagnosed leukocytosis as a typical artefact associated with cryoglobulinaemia. Treatment with chlorambucil (10-20 mg/d) and prednisolone (25 mg/d), for 14 days every 4 weeks, and finally interferon alpha-2b (5 mill. IU/d) reduced the cryoglobulin concentration to 150 mg/dl. Acral cyanosis and haemorrhages have not recurred since then. No cause of the cryoglobulinaemia has been found.