Aetiology

Erythrocytosis may occur secondary to:

• congenital caus
  • high oxygen-affinity haemoglobin
  • erythropoeitin receptor mediated
  • Chuvash erythrocytosis (VHL gene mutation) (1)
• acquired causes
  • hypoxia with decreased oxygen saturation:
    • decreased atmospheric oxygen e.g. high altitude
    • chronic heart disease:
      • congenital e.g. pulmonary stenosis, septal defect, patent ductus arteriosus
      • acquired e.g. chronic rheumatic mitral disease
    • arteriovenous fistula
  • impaired pulmonary ventilation:
    • alveolar-capillary block e.g. Hamman-Rich syndrome, sarcoidosis, lymphangitic cancer
    • alveolar hypoventilation e.g. bronchial asthma
    • restriction of pulmonary vascular bed e.g. primary pulmonary hypertension, mitral stenosis, emphysema
    • haemoglobins with abnormally high oxygen affinity
  • abnormal haemoglobin pigments e.g. methaemoglobinaemia
  • increased erythropoietin secretion:
    • renal disease:
      • hydronephrosis
      • renal cysts
      • benign tumours
      • occurs in up to 5% of renal cell carcinomas
      • 10-17% of kidney transplant recipients
    • other tumors - e.g. cerebellar haemangioblastoma, uterine fibromyomas
  • increased androgen:
    • phaeochromocytoma
    • Cushing's syndrome
    • masculinizing ovarian tumors e.g. arrhenoblastoma
    • androgen abuse by athletes

Reference:

• (1) McMullin MF et al. Guidelines for the diagnosis, investigation and management of polycythaemia/erythrocytosis. Br J Haematol. 2005;130(2):174-95