Relapsed Babesia microti Infection Following Allogeneic Hematopoietic Cell Transplantation in a Patient With B-cell Acute Lymphoblastic Leukemia: Case Report and Review of the Literature

Abstract

A patient with relapsed/refractory B-cell acute lymphoblastic leukemia developed babesiosis prior to allogeneic hematopoietic cell transplantation while on atovaquone for Pneumocystis jirovecii pneumonia prophylaxis. Despite receiving a prolonged course of atovaquone and azithromycin until whole blood Babesia microti DNA was no longer detected by polymerase chain reaction, her post-transplant course was complicated by relapsed babesiosis. We investigate the potential host and parasite characteristics causing relapsing/persistent infection.

Babesia microti with multiple resistance mutations detected in an immunocompromised patient receiving atovaquone prophylaxis

“…We also identified a V141A substitution, which has been previously reported in a relapsing B. microti infection and has been suggested to confer resistance 7 . Two distinct nucleotide mutations led to the amino acid substitution M134I; at a lower allele frequency, one variant also produced M134T, which has been identified in another case 17 . These mutations underscore the importance of this position in atovaquone resistance.…”

Babesia microtiVariant With Multiple Resistance Mutations Detected in an Immunocompromised Patient Receiving Atovaquone Prophylaxis

“…We also identified a V141A substitution, which has been previously reported in a relapsing B. microti infection and has been suggested to confer resistance [ 7 ]. Two distinct nucleotide mutations led to the amino acid substitution M134I; at a lower allele frequency, 1 variant also produced M134T, which has been identified in another case [ 17 ]. These mutations underscore the importance of this position in atovaquone resistance.…”

Acute hemolytic anemia after hematopoietic stem cell transplantation: An unusual invader

“…The patient in this case confirmed a history of tick bites while he was taking many walks in heavily wooded areas known to be harboring ticks 5 weeks before his symptoms appeared. Rarely, babesiosis can complicate the course of HSCT recipients especially in asplenic patients or with patients who received B‐cells depletion with anti‐CD20 antibodies 3 . The most common hematological manifestations include thrombocytopenia, immune, and non‐immune hemolytic anemia, and lymphopenia 4 .…”

“…Rarely, babesiosis can complicate the course of HSCT recipients especially in asplenic patients or with patients who received B-cells depletion with anti-CD20 antibodies. 3 The most common hematological manifestations include thrombocytopenia, immune, and non-immune hemolytic anemia, and lymphopenia. 4 The diagnosis is usually established by the identification of the organisms on a thin blood smear.…”