Persistent spontaneous heparinaemia in systemic mastocytosis

Area of Science:

• Hematology
• Oncology
• Biochemistry

Background:

• Systemic mastocytosis (SM) is a rare disorder characterized by abnormal mast cell proliferation.
• SM can involve multiple organ systems, including the lymphatic, digestive, nervous, and skeletal systems.
• Heparinemia, the presence of heparin in the blood, is an unusual complication of SM.

Observation:

• A patient with systemic mastocytosis presented with persistent heparinemia.
• The circulating anticoagulant was investigated using both conventional and specific assays.
• The anticoagulant exhibited properties consistent with heparin.

Findings:

• The anticoagulant was confirmed to be heparin through titrimetric assays with protamine sulfate.
• A specific amidolytic assay demonstrated the heparin's Xa-inhibiting properties.
• The identified human circulating heparin showed low specific activity relative to its weight.

Implications:

• This case highlights an uncommon manifestation of systemic mastocytosis.
• Understanding the characteristics of heparin produced in SM is crucial for patient management.
• Further research may elucidate the mechanisms linking SM and heparin production.