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Transient erythrophagocytosis in Diamond-Blackfan anemia
I Sekine1, T Masuda, Y Kawamura
1Department of Pediatrics, National Defense Medical College, Tokorozawa, Japan.
Insights
Diamond-Blackfan anemia (DBA) in an infant showed red cell aplasia. Erythrophagocytosis, or red blood cell destruction by immune cells, may cause DBA symptoms when steroid treatment is reduced.
Area of Science:
- Hematology
- Pediatric Hematology
- Genetics
Background:
- Diamond-Blackfan anemia (DBA) is a rare congenital disorder characterized by severe anemia.
- DBA typically presents with macrocytic pure red cell hypoplasia and reduced erythroid precursors.
Observation:
- A 4-month-old Japanese infant presented with DBA, exhibiting reticulocytopenia and increased fetal hemoglobin.
- The infant showed a poor response to conventional corticosteroid doses but improved with high-dose therapy.
Findings:
- Erythrophagocytosis was observed in bone marrow histiocytes during prednisone tapering when hemoglobin levels dropped.
- This phenomenon was absent before and during high-dose corticosteroid treatment, suggesting a link to red cell aplasia.
Implications:
- The findings suggest erythrophagocytosis may play a role in the pathogenesis of pure red cell aplasia and reticulocytopenia in DBA.
- This observation could inform future therapeutic strategies for managing DBA, particularly concerning corticosteroid dosage and potential immunomodulatory approaches.
Abstract:
We report on a 4-month-old Japanese infant girl with Diamond-Blackfan anemia (DBA) as shown by congenital macrocytic pure red cell hypoplasia with marked reduction of erythroid precursors in bone marrow, reticulocytopenia, increased fetal hemoglobin, and elevated adenosine deaminase activity in peripheral blood. She responded poorly to conventional doses of corticosteroids, however, with high-dose corticosteroids she responded with reticulocytosis and an elevation of hemoglobin level above 12 g/dL. Erythrophagocytosis was noted during the tapering period of prednisone when her hemoglobin level declined to 7.6 g/dL and reticulocyte level to 0.4%. At that time, the erythrophagocytosis was noted in about 60% of marrow histiocytes. These findings were not observed prior to or during the high dose prednisone therapy. We speculate that one of the causes of pure red cell aplasia and reticulocytopenia in DBA is mediated by erythrophagocytosis.