A 38-year-old woman from rural Maharashtra presents with progressive fatigue, dyspnea on exertion, and jaundice for 3 weeks. She has a history of recurrent episodes of similar symptoms over the past 2 years. Physical examination reveals splenomegaly and mild hepatomegaly. Laboratory investigations show hemoglobin 7.2 g/dL, reticulocyte count 8%, indirect bilirubin 3.2 mg/dL, and haptoglobin <10 mg/dL. Peripheral blood smear shows spherocytes, polychromasia, and occasional nucleated red blood cells. What is the most likely diagnosis?

Explanation

## Clinical Presentation and Laboratory Findings This patient presents with classic features of hemolytic anemia: jaundice, splenomegaly, elevated reticulocyte count (8%), elevated indirect bilirubin, and low haptoglobin. The **recurrent episodes** over 2 years and **female gender** are key clues pointing away from hereditary conditions. ## Peripheral Blood Smear Interpretation | Finding | Autoimmune HA | Hereditary Spherocytosis | G6PD Deficiency | Thalassemia Major | |---------|---------------|-------------------------|-----------------|-------------------| | **Spherocytes** | Present (immune coating) | Present (intrinsic RBC defect) | Absent | Absent | | **Polychromasia** | Marked | Marked | Present (during crisis) | Marked | | **Nucleated RBCs** | Common | Rare | Rare | Common | | **Target cells** | Absent | Absent | Absent | Present | | **Osmotic fragility** | Normal | Increased | Normal | Normal | | **Direct Coombs test** | **Positive** | Negative | Negative | Negative | **Key Point:** While both AIHA and hereditary spherocytosis show spherocytes on smear, the **positive direct antiglobulin test (Coombs)** is diagnostic of AIHA. The recurrent nature and female predominance (warm AIHA is more common in women) further support AIHA. ## Why Spherocytes Appear in Both Conditions 1. **AIHA:** IgG antibodies coat RBCs → complement activation → membrane loss → spherocyte formation 2. **Hereditary spherocytosis:** Spectrin/ankyrin deficiency → membrane instability → spherocyte formation (intrinsic defect) **Clinical Pearl:** Spherocytes in AIHA are **immune-coated** (positive DAT), whereas in hereditary spherocytosis they result from a **membrane protein defect** (negative DAT). This distinction is critical for diagnosis. **High-Yield:** The combination of **spherocytes + positive DAT + elevated reticulocyte count + elevated indirect bilirubin + low haptoglobin** is pathognomonic for AIHA. **Mnemonic — AIHA Red Flags:** **WARM** — Woman, Antibody-coated, Recurrent episodes, Membrane loss (spherocytes) ## Management Implications AIHA is treated with **corticosteroids** (first-line), whereas hereditary spherocytosis is managed with **folic acid supplementation** and **splenectomy** if needed. The recurrent nature and response to immunosuppression (if treated) would confirm AIHA.