Management of Autoimmune Hemolytic Anemia

Introduction

Autoimmune hemolytic anemia (AIHA) is a condition where the immune system produces antibodies that attack and destroy the body's own red blood cells, as suggested by clinical guidelines and the Journal of Clinical Oncology 1

The American Society of Clinical Oncology recommends rituximab 375 mg/m² weekly for 4 weeks, which is particularly effective in cold agglutinin disease 1
Cyclophosphamide (1-2 mg/kg/day) is an alternative option for treating autoimmune hemolytic anemia, as suggested by clinical guidelines 1
Combination of rituximab and cyclophosphamide for at least 5 weeks is also an alternative option for treating autoimmune hemolytic anemia, according to the American College of Clinical Oncology 1
Initial treatment with prednisone 1-2 mg/kg/day orally and folic acid 1 mg daily supplementation is recommended for patients with immune-mediated hemolytic anemia, as suggested by clinical guidelines and the Journal of Clinical Oncology 1
Prednisone should be continued until hemoglobin stabilizes and hemolysis markers improve, then tapered gradually based on clinical response, according to standard treatment protocols and the American College of Clinical Oncology 1, 2

For patients with Grade 3-4 AIHA due to immune checkpoint inhibitors, the recommended treatment is to permanently discontinue the immune checkpoint inhibitor, admit to hospital, and consult hematology, with prednisone 1-2 mg/kg/day ± rituximab and/or cyclophosphamide, as suggested by clinical guidelines 1
If there is worsening or no improvement, cyclosporine or immunosuppression/immunoadsorption should be added to the treatment, according to the Journal of Clinical Oncology 1

A thorough diagnostic evaluation is essential to determine the specific type of hemolytic anemia, including laboratory testing such as:

Test	Indication
Complete blood count with peripheral smear	Initial diagnosis
Comprehensive hemolysis panel	Hemolysis evaluation
Direct and indirect antiglobulin testing	Immune hemolysis diagnosis
Reticulocyte count	Erythropoiesis evaluation
Osmotic fragility test, ektacytometry, and genetic testing	Hereditary spherocytosis (if spherocytes are present)
Hemoglobin electrophoresis and genetic testing	Hemoglobinopathies
Coagulation studies (PT, PTT, fibrinogen), platelet count, ADAMTS13 activity (TTP), and evaluation for DIC, HUS, and malignant hypertension	Microangiopathic hemolytic anemia (if schistocytes are present)

Bone marrow aspiration and biopsy with immunophenotyping is recommended for diagnosis, as suggested by the Annals of Oncology and the National Comprehensive Cancer Network 6, 4
Testing for MYD88 (L265P) mutation is recommended, particularly if Waldenström's macroglobulinemia is suspected, according to the National Comprehensive Cancer Network 4

Weekly monitoring of complete blood count, reticulocyte count, and hemolysis markers is recommended for patients with immune-mediated hemolytic anemia, as suggested by clinical guidelines and the Journal of Clinical Oncology 1
Regular monitoring of hemolysis markers (LDH, haptoglobin, bilirubin) is recommended to assess disease activity, according to the Journal of Clinical Oncology 1
Assessing response to therapy and adjusting treatment accordingly is crucial for effective management, as suggested by the Journal of Clinical Oncology 1
Blood transfusion should be done with caution, and discussion with the blood bank team is necessary prior to transfusions in patients with immune hemolysis, as recommended by clinical guidelines and the American Association of Blood Banks 1, 7
RBC transfusion to target Hgb 7-8 g/dL is recommended, with notification of the blood bank of immune hemolysis before transfusion, according to the Journal of Clinical Oncology and the American Association of Blood Banks 1, 7

Autoimmune disease workup should include antinuclear antibodies (ANA), anti-dsDNA, complement levels (C3, C4), and rheumatoid factor, as part of a comprehensive diagnostic evaluation 1
Infectious disease evaluation should include viral serologies (EBV, CMV, HIV, hepatitis) and Mycoplasma testing, to rule out underlying infections 1
Medication review is recommended to identify potential drug-induced hemolysis, according to the Journal of Clinical Oncology 1
Evaluation for underlying causes, such as infections, malignancies, and autoimmune disorders, should be conducted, as suggested by the American College of Physicians 1
CT scan of chest, abdomen, and pelvis with IV contrast or PET-CT is recommended to assess for lymphadenopathy, splenomegaly, and other extramedullary disease, as suggested by the National Comprehensive Cancer Network 4

Thromboprophylaxis with low-molecular-weight heparin (LMWH) is recommended for hospitalized patients with hemolysis, as suggested by the American Society of Hematology 8
Patients with hemolysis have increased thrombotic risk even when not on active treatment, and disseminated intravascular coagulation (DIC), chemotherapy-induced hemolysis, and severe anemia should be recognized and managed, as recommended by the American College of Physicians 8, 1