Case Presentation: A 27 y.o. male with a history of pre-B cell ALL in complete remission on maintenance therapy with vincristine, 6-mercaptopurine, methotrexate, and receiving intrathecal methotrexate for CNS prophylaxis presented with a 2 week history of fevers, productive cough, night sweats, and fatigue. He had no recent exposure to children or sick contacts. Physical exam was notable for tachycardia, fever of 103oF, and pallor, with otherwise unremarkable pulmonary exam. On admission, labs were notable for WBC was 0.9×103 with an absolute neutrophil count of 738, Hb 6 g/dL, and platelets 169×103 (baseline: WBC 3.5-4 x103, Hg 14 g/dL, and platelets 225 x103). Reticulocyte index was 0.02. A chest CT revealed diffuse ground-glass opacities. A bone marrow biopsy revealed a hypocellular marrow with widespread, enlarged erythroblasts with intranuclear ground glass inclusions and chromatin margination in a background of erythroid hypoplasia characteristic for PB19. There was no evidence of leukemia. Infectious evaluation for respiratory viruses, endemic and opportunistic fungi, including diagnostic bronchoscopy with bacterial, viral, fungal and pneumocystis testing, was otherwise negative. Following return of characteristic bone marrow biopsy findings and progressive hypoxia on hospital day 6, 2 g/kg over 5 days IVIG therapy was initiated. He was further supported with RBC transfusions, folic acid, and cyanocobalamin. His fevers quickly abated and pulmonary symptoms improved. A serum parvovirus DNA PCR obtained on admission subsequently returned as positive.
Discussion: Parvovirus B19 (PB19) presentation and severity varies depending on the immune and hematologic status of the host, ranging from erythema infectiosum or transient polyarthropathy in immunocompetent patients to transient aplastic crisis in individuals with hemaglobinopathies. In immunosuppressed patients, PB19 can present with a pure red-cell aplasia, chronic anemia, with rare involvement of other cell lines. Pulmonary manifestations are exceedingly rare, with only several case reports published. The case presented was unique, being an adult with acute lymphoblastic leukemia (ALL) who presented with PB19 manifested by fevers, agranulocytosis, anemia, and pneumonia responsive to intravenous immunoglobulin (IVIG) therapy.
Conclusions: PB19 has been reported as a cause of unexplained cytopenias in children undergoing treatment for ALL. However, its frequency in similar adult populations is not described. Additionally, this patient had unique manifestations with pneumonia and atypical cytopenias. This case highlights the variability in clinical presentation and importance of considering B19 in immunosuppressed patients presenting with fevers and unexplained cytopenias. Treatment with IVIG resulted in marked clinical improvement. Improvement in reticulocytopenia may herald recovery and may have utility in monitoring recovery.