Coombs test is necessary when autoimmunity to red blood cells is a consideration in the differential diagnosis, including warm and cold hemolytic anemia. Following are some indications where testing becomes useful:

Autoimmune hemolytic anemia

Drug-induced immune hemolytic anemia

Alloantibodies-mediated hemolytic transfusion reactions

Hemolytic disease of the newborn

Systemic lupus erythematosus (without hemolytic anemia)

• Theis SR, Hashmi MF. Coombs Test. [Updated 2022 Sep 12]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK547707/