[A case of hookworm infestation with dissociation values between FDP-E and FDP-D dimer]

Area of Science:

• Hematology
• Parasitology
• Biochemistry

Background:

• Hookworm (Necator Americanus) infestation can cause bleeding disorders.
• Platelet abnormalities, including morphological and functional changes, have been observed in parasitic infections.
• Fibrinogenolysis and fibrinolysis are crucial components of the coagulation cascade, and their dysregulation can lead to bleeding.

Observation:

• A five-year-old girl presented with bleeding tendency and transient platelet abnormalities.
• The patient exhibited significantly accelerated fibrinogenolysis and/or fibrinolysis, evidenced by a marked discrepancy between FDP-E and D-dimer assay results.
• D-dimer values were substantially lower than expected based on FDP-E levels during hospitalization.

Findings:

• Accelerated fibrinogenolysis/fibrinolysis was likely induced by circulating protease(-like) agents produced by the hookworm.
• Limited involvement of plasmin and granulocyte elastase was suggested by enzyme-inhibitor complex analysis.
• Other causes, such as blast- or tumor-associated proteases, were ruled out based on clinical presentation.

Implications:

• This case highlights a rare complication of hookworm infestation, emphasizing the need for thorough parasitic evaluation in bleeding disorders.
• The findings suggest a unique mechanism of coagulation system dysregulation by parasitic factors.
• Further research into the specific parasitic agents and their mechanisms is warranted to understand the pathogenesis of bleeding and platelet abnormalities.