🩸 Pancytopenia is defined as a simultaneous reduction in all three major blood cell lines: red blood cells (anaemia), white blood cells (leukopenia), and platelets (thrombocytopenia). It is a clinical finding, not a diagnosis, and always warrants investigation for an underlying cause. 👉 Causes range from bone marrow failure and infiltration to nutritional deficiencies, infections, and autoimmune disorders. The clinical consequences depend on which cell line predominates (e.g. anaemia → fatigue, leukopenia → infection risk, thrombocytopenia → bleeding).

📖 Definition

🧬 Cell Type	📌 Definition	⚠️ Effects of Pancytopenia
Red Blood Cells (RBCs)	Carry oxygen throughout the body.	➡️ Anaemia → Fatigue, pallor, SOB, weakness due to reduced oxygen delivery.
White Blood Cells (WBCs)	Defend the body against infections.	➡️ Leukopenia → Recurrent infections, impaired immunity.
Platelets	Essential for clotting and prevention of bleeding.	➡️ Thrombocytopenia → Easy bruising, petechiae, risk of haemorrhage.

🧾 Causes of Pancytopenia

🦴 Bone Marrow Failure: Aplastic anaemia, myelodysplastic syndrome, leukaemia, myelofibrosis.
🦠 Bone Marrow Infiltration: Metastatic cancer, lymphoma, multiple myeloma.
💊 Bone Marrow Suppression: Chemotherapy, radiotherapy, cytotoxic drugs.
🥦 Nutritional Deficiencies: Vitamin B12 or folate deficiency.
🧬 Infections: HIV, hepatitis, TB, sepsis.
🦋 Autoimmune Diseases: SLE, rheumatoid arthritis.
🫀 Hypersplenism: Cirrhosis, portal hypertension → splenic sequestration.
👶 Congenital Conditions: Fanconi anaemia, Shwachman-Diamond syndrome.
☠️ Toxins: Alcohol, benzene, drugs.

🧩 Clinical Features

🔴 Anaemia: Fatigue, pallor, SOB.
🟡 Thrombocytopenia: Petechiae, bruising, gum/nose bleeds, menorrhagia.
⚪ Leukopenia: Recurrent infections, fever.
🌡️ Systemic: Fever, weight loss, night sweats (malignancy/infection).
🫁 Splenomegaly: Hypersplenism or haematological disorders.

🔎 Diagnosis

🩸 Full Blood Count (FBC): Confirms ↓ RBC, WBC, platelets.
🔬 Peripheral Blood Smear: Morphology of blood cells.
🦴 Bone Marrow Biopsy: Determines cause (failure vs infiltration vs suppression).
🥦 Serum Levels: Vitamin B12, folate.
🦠 Infection Screening: HIV, hepatitis, TB.
🩻 Imaging: CT/US for splenomegaly or malignancy.
🧪 Autoimmune Screening: ANA, rheumatoid factor.

📊 Common Causes and Management

Cause	🧩 Features	🔎 Diagnosis	💊 Management
Aplastic Anaemia	Fatigue, recurrent infections, bleeding	Hypocellular marrow, normal morphology	Immunosuppressants, bone marrow transplant, transfusions
Leukaemia	Fatigue, fever, weight loss, bruising, splenomegaly	Hypercellular marrow, blasts on smear, flow cytometry	Chemotherapy, transplant, supportive transfusions
Myelodysplastic Syndrome	Fatigue, infections, bruising	Dysplastic marrow, cytogenetic abnormalities	Azacitidine, G-CSF, transplant in young
Vitamin B12 / Folate Deficiency	Anaemia, glossitis, neuropathy (B12)	Low B12/folate, macrocytosis, megaloblastic marrow	Supplement replacement + treat cause
Infections (HIV, Hepatitis, TB)	Fever, weight loss, hepatosplenomegaly	Positive serology, marrow infiltration	Treat infection, supportive care
Autoimmune (SLE, RA)	Fatigue, joint pain, bruising	Pancytopenia, ANA/anti-dsDNA	Steroids, immunosuppressants, transfusions
Hypersplenism	Splenomegaly, anaemia, infections, bruising	Exam + US/CT confirms	Treat cause, splenectomy if severe

💊 Management Principles

🎯 Treat underlying cause (e.g. antivirals, chemo, steroids, nutritional supplements).
🩸 Supportive care: blood/platelet transfusions, G-CSF if neutropenic.
🦴 Bone marrow/stem cell transplant in severe or malignant cases.
🫁 Splenectomy in refractory hypersplenism.
🛡️ Prevent infections: vaccination, prophylactic antibiotics if high-risk.

💡 Tips & Pearls

🔑 Pancytopenia is a syndrome, not a diagnosis — always ask “what is causing this?”
⏱️ Early bone marrow biopsy is key when no clear cause is found.
👵 New-onset pancytopenia in older adults → think MDS or leukaemia.
🥦 Macrocytosis + pancytopenia → suspect B12/folate deficiency before bone marrow failure.
🫀 Splenomegaly + pancytopenia → consider hypersplenism or lymphoma.
⚠️ Neutropenic sepsis is a medical emergency → broad-spectrum antibiotics within 1 hour.
📉 Alcohol and drugs (e.g. methotrexate) are common iatrogenic causes → always review medications.

💡 Teaching Pearl: Pancytopenia is a syndrome, not a diagnosis. Always look for the underlying cause. In the UK, urgent haematology referral and bone marrow biopsy are recommended if unexplained or persistent.

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Pancytopenia