A 38-year-old woman from rural Maharashtra presents with a 3-month history of progressive fatigue, dyspnea on exertion, and recurrent oral ulcers. On examination, she has mild hepatosplenomegaly and generalized lymphadenopathy. Laboratory investigations reveal: Hemoglobin 7.2 g/dL, WBC 2,800/μL, platelets 65,000/μL. Peripheral blood smear shows normocytic RBCs with occasional schistocytes. Bone marrow aspiration and biopsy show hypercellular marrow with increased erythroid and myeloid precursors, but no dysplasia or infiltration. Reticulocyte count is 8.2%. What is the most likely diagnosis?

Explanation

## Clinical Diagnosis: Evans Syndrome with Secondary Immune Neutropenia ### Key Clinical Features **Key Point:** Evans syndrome is characterized by simultaneous or sequential development of autoimmune hemolytic anemia (AIHA) and immune thrombocytopenia (ITP), with immune neutropenia occurring in approximately 5–10% of cases (Harrison's Principles of Internal Medicine, 21e, Ch. 175). ### Diagnostic Reasoning | Feature | Finding | Significance | |---------|---------|---------------| | **Hemoglobin** | 7.2 g/dL | Moderate anemia (hemolytic) | | **WBC** | 2,800/μL | Mild leukopenia — immune-mediated neutrophil destruction | | **Platelets** | 65,000/μL | Moderate thrombocytopenia (immune-mediated) | | **Schistocytes on smear** | Occasional | Reflect fragmentation during intravascular/splenic hemolysis in AIHA, NOT microangiopathy | | **Reticulocyte count** | 8.2% | Elevated — appropriate compensatory marrow response | | **Bone marrow** | Hypercellular, no dysplasia | Rules out primary marrow failure; confirms peripheral destruction | | **Hepatosplenomegaly + lymphadenopathy** | Present | Extramedullary hematopoiesis, splenic sequestration, immune activation | ### Clarification on Schistocytes in Evans Syndrome Schistocytes are classically associated with microangiopathic hemolytic anemia (MAHA) as seen in TTP/HUS. However, **occasional schistocytes can also appear in AIHA** due to mechanical fragmentation of antibody-coated RBCs during splenic passage and intravascular turbulence. The key distinguishing point here is: - **Quantity**: TTP produces *numerous* schistocytes (>1% of RBCs); Evans syndrome may show only *occasional* schistocytes. - **Clinical context**: This patient lacks the TTP pentad (no neurological symptoms, no renal dysfunction, no fever). - **Bone marrow**: Hypercellular marrow is inconsistent with TTP (which does not affect marrow cellularity in this way). ### Pathophysiology of Evans Syndrome 1. **Immune hemolysis**: IgG autoantibodies bind RBC surface antigens → complement-mediated lysis and/or splenic sequestration. 2. **Immune thrombocytopenia**: Antiplatelet IgG antibodies → platelet destruction in the spleen. 3. **Immune neutropenia**: Antineutrophil antibodies → neutrophil destruction (WBC 2,800/μL reflects this); present in ~5–10% of Evans cases, distinguishing it from simple AIHA+ITP (Option A). 4. **Hypercellular marrow**: Compensatory erythroid and myeloid hyperplasia — confirms peripheral destruction, not marrow failure. **High-Yield:** The triad of **immune hemolytic anemia + immune thrombocytopenia + immune neutropenia** with a **hypercellular marrow and elevated reticulocyte count** is the hallmark of Evans syndrome with secondary immune neutropenia. ### Why Not the Other Options? - **Option A (AIHA + ITP without neutropenia)**: Does not account for the leukopenia (WBC 2,800/μL). Evans syndrome specifically includes the neutropenic component, making Option B more complete and accurate. - **Option C (TTP)**: TTP requires the pentad — MAHA, thrombocytopenia, neurological symptoms, renal dysfunction, and fever. This patient has none of the neurological or renal features. Additionally, TTP does not produce a hypercellular marrow response. - **Option D (SLE with pancytopenia)**: SLE can cause pancytopenia, but the clinical picture here (hypercellular marrow, elevated reticulocytes, schistocytes) points specifically to peripheral immune destruction rather than the multisystem autoimmune picture of SLE. No mention of malar rash, serositis, or renal involvement. ### Diagnostic Confirmation - **Direct Antiglobulin Test (DAT/Coombs)**: Positive (IgG ± complement on RBCs) - **Platelet-associated IgG (PAIgG)**: Elevated - **Antineutrophil antibodies**: May be positive - **Hemolysis markers**: Elevated LDH, elevated indirect bilirubin, low haptoglobin **Clinical Pearl:** In Evans syndrome, the **hypercellular marrow with elevated reticulocytes** confirms that cytopenias result from **peripheral immune destruction**, not marrow failure. The WBC of 2,800/μL (immune neutropenia) is the key feature that elevates this diagnosis from simple AIHA+ITP (Option A) to full Evans syndrome (Option B). **Mnemonic:** **EVANS** = **E**rythrocyte destruction + **V**alues (cytopenias) + **A**utoimmune + **N**eutropenia + **S**plenomegaly [cite: Harrison 21e Ch 175; Williams Hematology 9e Ch 53]