Abstract
Leukopenia is common among lung transplant (LT) recipients and medications are the most common offending agents, including valganciclovir (VG), mycophenolate mofetil (MMF), and trimethoprim-sulfamethoxazole (TMS). If leukopenia persists despite stopping culprit medications, patients are typically referred for a bone marrow biopsy (BMB) and parvovirus B19 (B19) testing. In immunocompromised hosts, persistent B19 infection most commonly manifests as pure red cell aplasia and chronic anemia. We report unusual cases of refractory leukopenia in 2 LTR who were found to have B19 on BMB.
A 68-year-old woman had bilateral LT (BLT) in February 2020 for idiopathic pulmonary fibrosis (IPF). She had basiliximab induction and our standard immunosuppressive and prophylactic regimen: MMF, VG, and TMS. Four months after BLT she became neutropenic, but not lymphopenic, anemic, or thrombocytopenic. MMF, VG, and TMS were stopped, but she continued to require recurrent filgrastim as her absolute neutrophil count was <500 cells/µL. BMB revealed a hypocellular-for-age bone marrow with diminished, but maturing trilineage hematopoiesis, and PCR detected B19. She was prescribed IVIG, but it was held due to rapidly progressive renal dysfunction. To date, she remains off MMF, VG, and TMS, with letermovir, acyclovir, and pentamidine replacing the latter 2 medications. She is still leukopenic and now also mildly anemic. A 62-year-old man had BLT in August 2020 for IPF. He had basiliximab induction and our standard immunosuppressive and prophylactic regimen: MMF, VG, and TMS. Two months after BLT he became leukopenic and mildly anemic, but not thrombocytopenic. MMF, VG, and TMS were stopped, but he continued to require recurrent filgrastim. BMB revealed a hypocellular-for-age bone marrow (10-15%), and PCR detected B19. He was prescribed IVIG, but IVIG infusions are yet to begin. To date, he remains off of MMF, VG, and TMS, with letermovir, acyclovir, and atovaquone replacing the latter 2 medications. He remains leukopenic, but not anemic or thrombocytopenic.
We report unusual cases of refractory leukopenia, without significant anemia, in 2 LT recipients with B19 identified on BMB. We suspect that B19 is the culprit as stopping offending medications has been ineffective and hematologic workup has been unrevealing.