Basophilia

Basophilia is not a frequent finding in peripheral blood. This condition most commonly manifests as a reactive mechanism associated with eosinophilia and an absolute basophil count exceeding 200 cells/µL.

Increased basophils (> 0.1 x 10⁹/l) seen in:

• viral infections
• urticaria
• post-splenectomy
• myxoedema
• ulcerative colitis
• systemic mastocytosis
• malignancy
• myeloproliferative disorders:
  • chronic myeloid leukaemia
  • myelofibrosis
  • polycythaemia rubra vera
• haemolysis

Basophilia does not characteristically occur in secondary polycythaemia.

Note that excessive basophilia in chronic myeloid leukaemia may indicate the transformation into an accelerated or 'blastic' phase.

Transient basophilia is a reactive response, especially to an acute viral illness. Persistent basophilia on serial blood counts for longer than 8 weeks suggests an underlying malignancy or myeloproliferative disease.

Reference

1. Çehreli C. Diagnostic Problems in Chronic Basophilic Leukemia. Turk J Haematol. 2018 Nov 13;35(4):283-289