Post-Babesiosis Warm Autoimmune Hemolytic Anemia

Abstract

Background Babesiosis, a tickborne zoonotic disease caused by intraerythrocytic protozoa of the genus babesia, is characterized by nonimmune hemolytic anemia that resolves with antimicrobial treatment and clearance of parasitemia. The development of warm-antibody autoimmune hemolytic anemia (also known as warm autoimmune hemolytic anemia [WAHA]) in patients with babesiosis has not previously been well described. Methods After the observation of sporadic cases of WAHA that occurred after treatment of patients for babesiosis, we conducted a retrospective cohort study of all the patients with babesiosis who were cared for at our center from January 2009 through June 2016. Data on covariates of interest were extracted from the medical records, including any hematologic complications that occurred within 3 months after the diagnosis and treatment of babesiosis. Results A total of 86 patients received a diagnosis of babesiosis during the 7.5-year study period; 18 of these patients were asplenic. WAHA developed in 6 patients 2 to 4 weeks after the diagnosis of babesiosis, by which time all the patients had had clinical and laboratory responses to antimicrobial treatment of babesiosis, including clearance of Babesia microti parasitemia. All 6 patients were asplenic (P<0.001) and had positive direct antiglobulin tests for IgG and complement component 3; warm autoantibodies were identified in all these patients. No alternative explanation for clinical hemolysis was found. WAHA required immunosuppressive treatment in 4 of the 6 patients. Conclusions We documented post-babesiosis WAHA in patients who did not have a history of autoimmunity; asplenic patients appeared to be particularly at risk.

Babesiosis: Appreciating the Pathophysiology and Diverse Sequela of the Infection

“…In addition, this review discovered the following less commonly reported sequela or associated conditions: acute lung injury, pulmonary edema, warm autoimmune hemolytic anemia (WAHA) [11], thrombocytopenia [12], reactive hemophagocytosis or hemophagocytic lymphohistiocytosis (HLH) [13], hepatitis [14][15][16], hepatomegaly [14], splenomegaly [14], pancytopenia [17], septic shock [18], multiorgan failure, and even death [12][13][14][15][16][17][18].…”

Autoimmune hemolytic anemia associated with the use of immune checkpoint inhibitors for cancer: 68 cases from the Food and Drug Administration database and review

“…20 It has been suggested that an imbalance of regulatory T cells and an overactivity of B and T cells cause AIHA. 21,22 AIHA is more frequent in patients with lymphoproliferative disorders especially chronic lymphocytic leukemia, and seen in a variety of other conditions including viral infections, babesiosis, 23 and after allogeneic stem cell transplantation. 24 In most cases, no underlying cause 20,21 can be found.…”

Autoimmune hemolytic anemia associated with babesiosis

“…It is important to consider blood parasite infections as a probable cause of hemoglobinuria and warm AIHA [15, 16]. AIHA was recently reported in 7% of all patients with babesia infection in a series, but close to 30% in asplenic patients [35]. The mechanism for post-babesiosis AIHA (PB-AIHA) was proposed to be related to antibody-mediated and immune-complex- mediated hypersensitivity.…”