[Pseudoleukocytosis in cryoglobulinemia type I]

Area of Science:

• Hematology
• Immunology
• Dermatology

Background:

• A 54-year-old man presented with persistent leukocytosis of unknown origin.
• He later developed painful, transient cyanosis in his fingers, suggesting an underlying condition.

Observation:

• Further symptoms included acral hemorrhages after cold exposure.
• Laboratory tests revealed monoclonal IgG-kappa immunoglobulin, a positive antinuclear antibody test, and high cryoglobulin levels (800 mg/dl).

Findings:

• The initial leukocytosis was identified as a pseudoleukocytosis artifact caused by cryoglobulinemia.
• Treatment with chlorambucil, prednisolone, and interferon alpha-2b successfully reduced cryoglobulin levels to 150 mg/dl.

Implications:

• This case highlights the importance of considering cryoglobulinemia in patients with unexplained leukocytosis and acral vascular events.
• Effective management of cryoglobulinemia can prevent recurrence of severe symptoms like cyanosis and hemorrhage.