Neutropenia and Normocytic Anaemia

NEUTROPENIA

Differential Diagnoses

• Acute Infections (viral: EBV, CMV, influenza, hepatitis)

  • Often self-limiting, mild neutropenia resolving once infection clears

• Autoimmune Conditions (SLE, RA)

  • Immune-mediated peripheral destruction or bone marrow suppression

• Bone Marrow Suppression

  • Malignancies (leukaemia, myelodysplastic syndromes), infiltration, aplastic anaemia

  • Chemotherapy or radiation-induced (common iatrogenic cause)

• Drug-Induced

  • Certain antibiotics (trimethoprim-sulfamethoxazole), antipsychotics, anticonvulsants can cause neutropenia

  • Monitor FBC if on long-term or high-risk medications

When to Refer

• WCC <1 × 10^9/L or severe neutropenia (ANC <0.5 × 10^9/L)

  • High risk of severe infections (bacterial/fungal)

• Persistent / Recurrent Infections suggesting inadequate immune defence

• Systemic Illness with unexplained cytopenias or suspicion of bone marrow failure

Key Points

• Febrile Neutropenia: Medical emergency → urgent hospital referral for broad-spectrum IV antibiotics

  • Sepsis risk is high, especially with ANC <0.5 × 10^9/L

• Severe / Prolonged Neutropenia

  • Consider G-CSF (granulocyte colony-stimulating factor) to stimulate neutrophil production if recurrent infections or post-chemotherapy

  • Evaluate marrow function (bone marrow biopsy if indicated)

• Common, Mild Neutropenia

  • Often benign, especially with mild viral infections in children or transient autoimmune neutropenia

  • Monitor FBC trend over weeks to ensure recovery

NORMOCYTIC ANAEMIA

Differential Diagnoses

• Anaemia of Chronic Disease (ACD) / Anaemia of Chronic Inflammation

  • Associated with RA, CKD, T2DM, HF, IBD, malignancies

  • Inflammatory cytokines reduce erythropoietin responsiveness and iron mobilisation

  • Ferritin often normal or elevated, low TIBC, normal/low serum iron

• Acute Blood Loss

  • Initially normocytic before iron deficiency develops if bleeding continues

• Early Iron Deficiency

  • MCV may remain normal initially, eventually becomes microcytic

• Haemolytic Anaemia

  • RBC destruction (hereditary spherocytosis, sickle cell disease, autoimmune haemolysis)

  • Reticulocytosis with elevated unconjugated bilirubin, LDH, low haptoglobin

Key Investigations

• Reticulocyte Count

  • Differentiates underproduction (low retic) vs increased RBC destruction or blood loss (high retic)

• Haemolysis Workup

  • LDH, bilirubin, haptoglobin, peripheral smear (schistocytes, spherocytes, sickle cells)

• Markers of Inflammation

  • CRP, ESR often elevated in chronic disease

• Renal and Endocrine Status

  • CKD or hypothyroidism may present with normocytic anaemia

• Bone Marrow Assessment

  • If unexplained cytopenias or suspicion of marrow pathology

Management

• Anaemia of Chronic Disease

  • Address underlying inflammatory condition (RA control, infection treatment, better CKD management)

  • IV iron supplementation may help if functional iron deficiency present (low transferrin saturation, normal/high ferritin)

  • Erythropoiesis-stimulating agents in selected CKD patients with severe anaemia

• Acute Blood Loss

  • Identify and treat source of bleeding (GI bleed, trauma)

  • RBC transfusion if haemodynamically unstable or Hb <70 g/L in most stable adults (target higher threshold in cardiac disease)

• Early Iron Deficiency

  • Oral iron therapy (100–200 mg elemental iron daily) or IV iron if malabsorption or intolerance

  • Reassess MCV and iron studies over 2–3 months

• Haemolytic Anaemia

  • Tailor therapy based on aetiology (e.g. steroids for autoimmune, hydroxycarbamide for sickle cell, splenectomy in certain conditions)

• Supportive Care

  • Regular follow-up, monitor CBC trends to ensure response to therapy

  • Treat comorbidities (CKD, hypothyroidism) contributing to anaemia

  • Check for B12/folate deficiency if RBC indices shift or if clinical suspicion

  
  

Notes:

• Neutropenia and normocytic anaemia may co-exist in marrow disorders (myelodysplasia) or systemic diseases (SLE, chronic infections)

• Febrile Neutropenia requires urgent IV antibiotics and possible G-CSF if severe/prolonged

• For normocytic anaemia, always check reticulocyte count to distinguish underproduction vs blood loss/haemolysis

• Anaemia of Chronic Disease is common in older adults with multiple comorbidities (HF, T2DM, CKD) – treat underlying cause, consider IV iron if functional deficiency

• Consider referral to haematology if complex aetiologies, persistent cytopenias, or uncertain diagnosis