there is viral-induced myelosuppression. Once the clinical suspicion of autoimmune hemolytic anemia is made, direct antiglobulin test (DAT) or direct Coombs' test is the first line of investigation to confirm the presence of warm autoantibodies. Testing with polyspecific and IgG-specific antiglobulin agents is usually negative, and that with C3-specific agent may be positive. On excluding warm autoimmune hemolytic anemia (WAIHA), the cold agglutinin titer should be examined for cold agglutinin disease (CAD). The diagnosis of PCH is suspected when both WAIHA and CAD are excluded. The complement level is usually low. Donath-Landsteiner test is the confirmatory test for PCH. It involves the cooling of the patient's serum to 4°C to allow the absorption of anti-P autoantibodies to the red cells, followed by warming to 37°C to activate complement fixation and hemolysis. Indirect DL test with addition of ABO-compatible P antigen-positive blood can be performed in case the direct DL test is negative, since the complement in the original serum may be consumed and result in false negative. The hematopathological findings can reflect both the presence of intravascular hemolysis and the underlying immunological process. The complete blood count usually shows normocytic anemia. Reticulocytosis may be subtle in the acute phase. Peripheral blood smear may show corresponding polychromasia. Neutrophil erythrophagocytosis is suggestive of PCH, while the absence of red cell agglutination as in CAD or microspherocytosis in WAIHA should also be noted. Classification AIHA can be classified as warm autoimmune hemolytic anemia or cold autoimmune hemolytic anemia, which includes cold agglutinin disease and paroxysmal cold hemoglobinuria. These classifications are based on the characteristics of the autoantibodies involved in the pathogenesis of the disease. Each has a different underlying cause, management, and prognosis, making classification important when treating a patient with AIHA. Autoimmune hemolytic anemia Warm-antibody type Primary Secondary (lymphoproliferative disorders, autoimmune disorders) Cold-antibody type (anemia) Primary cold agglutinin disease Secondary cold agglutinin syndrome Associated with malignant disease Acute, transient, infection-associated (acute cold antibody mediated AIHA complicating Mycoplasma pneumoniae or viral infections) Chronic (lymphoproliferative disorders) Paroxysmal cold hemoglobinuria Idiopathic Secondary Acute, transient (Infections other than syphilis) Chronic (syphilis) Mixed cold- and warm-antibody type Idiopathic Secondary (lymphoproliferative disorders, autoimmune disorders) Drug-induced immune hemolytic anemia Autoimmune type Drug absorption type Neoantigen type Management Acute PCH is usually transient and self-limiting. Supportive treatment includes rest, normothermia and transfusion when indicated. Intensive care for the development of acute kidney injury should be offered. Plasmapheresis is proposed to