Parvovirus B19-induced aplastic anemia following mechanical valve replacement

Area of Science:

• Hematology
• Virology
• Cardiology

Background:

• Human parvovirus B19 infection typically causes mild symptoms in immunocompetent adults.
• Severe aplastic anemia is a rare complication, usually transient.
• Postoperative pancytopenia after mechanical valve replacement poses diagnostic challenges.

Purpose of the Study:

• To report a unique case of recurrent severe aplastic anemia caused by human parvovirus B19 in a postcardiotomy patient.
• To highlight the importance of considering viral etiologies in postoperative cytopenias.
• To emphasize multimodal laboratory correlation for accurate diagnosis.

Main Methods:

• Comprehensive laboratory evaluation including lactate dehydrogenase, haptoglobin, and reticulocyte production index.
• Human parvovirus B19 DNA testing.
• Serial echocardiograms to assess prosthetic valve function.
• Peripheral blood smear analysis.

Main Results:

• Patient presented with progressive pancytopenia despite a functioning prosthetic valve.
• Elevated LDH and undetectable haptoglobin initially suggested mechanical hemolysis.
• Suppressed reticulocyte production index and positive parvovirus B19 DNA confirmed viral marrow suppression.
• Absence of schistocytes and stable hemoglobinuria ruled out prosthetic valve-related hemolysis.

Conclusions:

• Human parvovirus B19 should be considered in the differential diagnosis of postoperative pancytopenia, irrespective of immune status.
• Disproportionate reticulocytopenia with normal hemolysis markers may indicate viral marrow infiltration.
• Echocardiography alone may not exclude subclinical hemolysis, necessitating integrated laboratory assessment.