Cryocrystalglobulinemia in hairy cell leukemia

Area of Science:

• Hematology
• Immunology
• Clinical Pathology

Background:

• Hairy cell leukemia (leukemic reticuloendotheliosis) is a rare B-cell malignancy.
• Cryoglobulinemia can cause pseudoleukocytosis, interfering with automated blood counts.
• Accurate white blood cell counts are crucial for monitoring leukemia treatment.

Observation:

• A patient diagnosed with hairy cell leukemia presented with an unexpectedly high white blood cell count.
• This spurious leukocytosis was attributed to a cryoglobulin that spontaneously crystallized.
• The cryoprotein was identified as IgG lambda, consistent with intracytoplasmic immunoglobulin in the patient's hairy cells.

Findings:

• The cryoglobulin, identified as IgG lambda, was responsible for the falsely elevated leukocyte count.
• The cryoprotein spontaneously disappeared within a four-day period.
• Prewarming blood samples to 37°C enabled reliable automated white blood cell counts using the Coulter Model S analyzer.

Implications:

• This case highlights the importance of recognizing cryoglobulinemia as a cause of pseudoleukocytosis in hematologic malignancies.
• Understanding the interaction between cryoproteins and automated cell counters is essential for accurate patient assessment.
• Proper sample handling, such as prewarming, can overcome analytical interference from cryoglobulins, ensuring reliable diagnostic and monitoring data.