A 42-year-old woman with a 3-year history of jaundice, splenomegaly, and recurrent hemolytic episodes presents with acute hemolysis (hemoglobin 7.8 g/dL, reticulocyte count 16%, elevated indirect bilirubin, elevated LDH). Direct antiglobulin test (DAT/Coombs) is strongly positive with IgG and C3 coating. What is the drug of choice for acute hemolytic episodes in warm autoimmune hemolytic anemia?

Explanation

## Clinical Diagnosis The presentation is diagnostic of **Warm Autoimmune Hemolytic Anemia (AIHA)**: - **Positive DAT with IgG and C3** — IgG antibodies coat RBCs; complement is activated - Elevated reticulocyte count, indirect bilirubin, and LDH - Chronic hemolysis with splenomegaly - Acute exacerbation ## Drug of Choice: Corticosteroids **Key Point:** **Corticosteroids are first-line therapy** for warm AIHA. They suppress antibody production and reduce splenic macrophage-mediated RBC destruction. **High-Yield:** Warm AIHA is an **extravascular hemolytic anemia** caused by IgG autoantibodies. Corticosteroids: 1. Inhibit B-cell antibody production 2. Reduce splenic macrophage Fc receptor expression 3. Suppress complement activation 4. Achieve complete remission in ~70–80% of patients **Clinical Pearl:** Typical dosing: Prednisolone 1 mg/kg/day (or methylprednisolone 500 mg IV daily for severe cases), then taper over weeks to months based on response. ## Pathophysiology and Treatment Hierarchy ```mermaid flowchart TD A[Autoimmune attack on RBCs<br/>IgG antibody coating]:::outcome --> B[Complement activation<br/>C3 deposition] B --> C[Splenic macrophages recognize<br/>IgG-coated RBCs via Fc receptors] C --> D[Extravascular hemolysis<br/>in spleen]:::urgent E[Corticosteroids]:::action --> F[Suppress antibody production] F --> G[Reduce Fc receptor expression] G --> H[Hemolysis resolves]:::outcome I[Refractory cases]:::decision --> J[Rituximab or splenectomy] ``` ## Treatment Algorithm for Warm AIHA | Stage | Intervention | Indication | Success Rate | |-------|-------------|-----------|---------------| | **First-line** | **Corticosteroids** | **All symptomatic patients** | **70–80%** | | **Second-line** | Rituximab or splenectomy | Steroid-refractory or steroid-dependent | 50–70% | | **Third-line** | Immunosuppressants (azathioprine, mycophenolate) | Refractory to above | Variable | | **Supportive** | Transfusion, folic acid | Severe anemia, chronic hemolysis | Adjunctive | **Mnemonic:** **WARM AIHA = Corticosteroids First** - **W**arm = IgG antibodies (vs. cold = IgM) - **A**utoimmune = antibody-mediated - **I**mmune = suppress with steroids - **H**emolytic = extravascular in spleen - **A**nemia = treat with **corticosteroids** **Warning:** Do NOT start rituximab or splenectomy before adequate trial of corticosteroids (4–6 weeks). Reserve these for steroid-refractory cases.