An unusual factor-X inhibitor in leprosy

Area of Science:

• Hematology
• Immunology
• Infectious Diseases

Background:

• Hansen disease, also known as leprosy, is a chronic infectious disease caused by Mycobacterium leprae.
• Autoimmune phenomena, including inhibitors of coagulation factors, can occur in infectious diseases.
• Coagulation factor X plays a critical role in the blood coagulation cascade.

Observation:

• Two patients with Hansen disease presented with a lupus-like anticoagulant.
• This inhibitor was specifically directed against the activation of coagulation factor X.
• Factor X activity was markedly depressed in one specific assay system.

Findings:

• Despite significant depression in one assay, factor X activity measured by three alternative assay systems yielded normal results.
• This discrepancy suggests assay-dependent sensitivity to the inhibitor.
• The inhibitor's presence indicates a complex interplay between infection and the coagulation system.

Implications:

• These findings highlight the potential for diagnostic discrepancies in coagulation factor assays when specific inhibitors are present.
• Understanding such inhibitors is crucial for accurate diagnosis and management of bleeding or thrombotic risks in patients with Hansen disease.
• Further research is needed to characterize the inhibitor and its precise mechanism of action.