Haematological aspects of splenectomy

Haematological aspects of splenectomy

Haematological Aspects of Splenectomy

Functions of the spleen 

  • Clearance of opsonized cells by splenic macrophages.
  • Trapping of abnormal RBCs by the reticular meshwork.
  • Antigen presentation – in the periarteriolar lymphatic sheaths and in the marginal zones of the lymphatic follicles (the T cell zones).
  • Antibody production – in the mantle zone of the lymphatic follicle (the B cell zone).
  • Haematopoiesis – in utero, during haemolysis, after stem-cell transplantation, etc.
  • Reservoir function – especially of granulocytes and platelets in the red pulp.
  • Haemostasis – production of factor VIII and von Willebrand factor by endothelial cells.

Causes of splenomegalyInfections

  • Viral – EBV, CMV, etc.
  • Bacterial – typhoid, brucellosis, bacterial endocarditis, etc.
  • Fungal – e.g. histoplasma
  • Protozoal – e.g. malaria, leishmania

 Haematological malignancies

  • Chronic leukaemias – CML* and CLL*
  • Acute leukaemias – AML and ALL
  • Other myeloproliferative disorders – e.g. myelofibrosis*, polycythemia, etc.
  • Other lymphoproliferative disorders – e.g. NHL, HD, hairy cell leukaemia*, etc.
  • Miscellaneous – malignant histiocytosis, etc.

 Haemolytic anaemias

  • Disorders of haemoglobin – sickling disorders and the thalassaemias*
  • Disorders of the RBC membrane – hereditary spherocytosis*, hereditary elliptocytosis*, etc.
  • Disorders of RBC enzymes – e.g. pyruvate kinase deficiency (rare) 

Other non-malignant haematological diseases

  • Autoimmune haemolytic anaemias*
  • Thrombocytopenias – ITP*, TTP*
  • Chronic neutropenias – e.g. Felty’s syndrome*
  •  Portal hypertension*
  • Autoimmune diseases – e.g. SLE
  • Chronic granulomatous conditions – e.g. sarcoidosis
  • Storage diseases – e.g. Gaucher’s and Niemann-Pick’s
  • Primary splenic problems – tumors, cysts, amyloid, etc.
  • Metastatic tumors to the spleen (very rare)

* may be indications for splenectomy 

Any thing that causes splenomegaly may be a cause of hypersplenism. Hypersplenism is defined as splenomegaly with any combination of clinically significant leukopenia, thrombocytopenia or anaemia.

Indications for splenectomy

  • Hypersplenism
  • Massive splenomegaly causing severe local symptoms
  • Splenic trauma
  • Splenic tumors
  • Staging of lymphoproliferative disorders such as Hodgkin’s disease

Hyposplenism – causes

  • Haematolgical – sickling disorders, NHL and HD, Fanconi’s anaemia
  • Immunological – SLE, rheumatoid arthritis, mixed connective tissue disease, Sjogren’s syndrome, chr. active hepatitis, ulcerative colitis, Crohn’s disease, graft versus host disease
  • Anatomic – congenital asplenia or hyposplenia, splenic vein occlusion, irradiation, tumors, amyloidosis, etc.

Complications of splenectomy

  • Post-splenectomy sepsis (splenectomy must be avoided in children less than 5 years and infection control measures need to be taken before and after splenectomy – see below)
  • Post-operative atelectasis
  • Splenic rupture and bleeding
  • Sub-phrenic abscess
  • Thrombocytosis – causing thromboembolism
  • Slightly increased risk of ischaemic heart disease

Post-splenectomy changes in the blood

  • Red cell changes – target cells, acanthocytes, erythroblasts, Howell-Jolly bodies, Heinz bodies, Pappenheimer bodies, slight reticulocytosis
  • Platelet changes – thrombocytosis, which may be persistent but which usually does not exceed 1000 x 109 / litre
  • White cell changes – initial neutrophilia, which then regresses. Lymphocytosis and monocytosis may persist.

Post-splenectomy sepsis

  • General – more frequent in younger patients but can also happen in adults; may occur years after splenectomy but most common in the first few months; usually abrupt onset, rapid course and cardiovascular collapse (due to adrenal haemorrhage – Waterhouse-Friderichsen syndrome) are features especially if due to N. meningitidis.
  • Pathophysiology – lack of splenic macrophages to clear opsonized microorganisms; lack of type-specific antibodies
  • Causative organisms – Bacteria such as Str. pneumoniae, H. influenza (types band f), N. meningitidis, Ps. aeruginosa, E. coli and other encapsulated organisms; Protozoa such as Plasmodium and Babesia.
  • Prevention – Avoid splenectomy if possible or delay till patient is older than 5 years; immunize with polyvalent pneumococcal, meningococcal and conjugated Haemophilus vaccines – preferably 2 weeks or at least 72 hours before splenectomy; prophylactic antibiotics such as Penicillin V 250mg (or Erythromycin if Penicillin sensitive) b.d. for 1 year post-splenectomy or till the patient is 18 years old; patient education; medical alert or other warning signs to be carried by the patient on his person.
  • Treatment  after a quick examination, take blood and other appropriate cultures and start on oral or iv antibiotics, e.g. a 3rd generation cephalosporin.

K.G. Badami MD, MRCPath, 
Consultant Haematologist 
Email : [email protected]