Pancytopenia

 

• Background

  Definition

  Deficiency in all 3 major blood components:

  • Anaemia (↓RBC).
  • Leukopaenia (↓WBC), the most dangerous component of which is neutropenia (↓neutrophils). Neutropenia is classified as mild (<1.5 x 109/L), moderate (<1.0 x 109/L), or severe (<0.5 x 109/L).
  • Thrombocytopaenia (↓PLT).

  Causes

  • ↓Production: bone marrow failure. Commonest cause.
  • ↑Destruction: sepsis, autoimmune disease such as SLE, RA.
  • Sequestration due to hypersplenism: secondary to liver disease, myeloproliferative disease, or infection.

  Causes of bone marrow failure

  Malignant infiltration:

  • Haematological: acute leukaemia, myeloma, myelofibrosis, lymphoma, myelodysplastic syndrome.
  • Non-haematological: bone mets from breast, prostate, lung, renal cell, or thyroid.

  Aplastic anaemia:

  • Rare: 1/200,000 annual incidence.
  • Idiopathic in 60%. May be autoimmune.
  • Drug causes: chemotherapy, radiotherapy, benzene, gold, penicillamine, sulfonamides, chloramphenicol.
  • Congenital causes: Fanconi's anaemia.
  • Viral causes: parvovirus B19, EBV, CMV, HIV, HBV.

  Megaloblastic anaemia:

  • ↓B12/folate
  • BM failure is a very rare complication.

• Signs and symptoms

  • Anaemia: fatigue, SOB, pallor, angina, and ↑HR.
  • Neutropenia: rapid dissemination of systemic infection.
  • Thrombocytopenia: bruising, GI and intracranial bleed.

• Investigations

  Identify pancytopaenia:

  • FBC: ↓Hb, ↓WBC, ↓PLT. MCV is usually normal but can be ↑.
  • Blood film: leukoerythroblastic picture i.e. immature RBCs and WBCs.
  • ↓Reticulocytes

  Identify cause:

  • B12 and folate.
  • Viral serology: parvovirus B19, EBV, CMV, HIV, HBV.
  • Auto-Ab screen.
  • Immunoelectrophoresis for paraproteins.
  • Abdo US for hypersplenism.

  Other tests:

  • Blood culture in neutropenia.
  • Coag to assess bleeding risk.

  Bone marrow sampling, usually from the posterior iliac crests:

  • Aspirate (fluid): cytology, IHC, cytogenetics.
  • Trephine biopsy (tissue sample): hypercellular in malignant infiltration, hypocellular in aplastic anaemia.

• Management

  • Supportive care: treat infection, transfuse (RBCs, platelets), fluids.
  • Haematopoietic stem cell transplantation may be needed.