Babesia Infection Reduces Red Cell Deformability

The United States reports the highest number of Babesia infections globally. Babesia, a tick-borne pathogen related to the malaria parasite, also infects RBCs leading to hemolytic anemia and other symptoms. Because blood donor testing is not universally implemented in the U.S. and individuals with sickle cell disease (SCD) require frequent transfusions, these individuals are vulnerable to transfusion-transmission of Babesia and may also be more susceptible to parasite-induced RBC rheology and membrane modifications. To explore the impact of Babesia on wild type (AA), sickle cell trait (AS), and sickle (SS) RBCs, researchers used ektacytometry—a laser-assisted optical analyzer that can measure the elongation of RBCs—and compared uninfected cells to those infected with Babesia. Wild-type RBCs had a mild reduction in deformability when infected, those with sickle cell trait (AS) had an intermediate reduction, but sickle (SS) RBCs had the most dramatic change in deformability when infected with Babesia. In addition, Babesia infection in SS RBCs resulted in increased vesicle formation (hypervesiculation) and a higher percentage of sickled cells—14.6% in infected SS RBCs compared to 6.6% in uninfected SS RBCs. These findings suggest Babesiosis induces significant changes in RBCs and exacerbates the sickle cell disease phenotype. Further studies are needed to better understand the impact of Babesia infection, especially in patients with SCD and heterozygous sickle trait.

References:

1. Jajosky RP and , SR Stowell; Babesianot only is invasive but creates RBC inflexibility. Blood 2025; 145 (19): 2114–2115
2. Beri D, Rodriguez M, Singh M, McLaughlin D, et al. Babesiosis and sickle red blood cells: loss of deformability, altered osmotic fragility, and hypervesiculation. Blood2025; 145 (19): 2202–2213