TABLE 1

Causes of erythrocytosis

Primary erythrocytosis
Increased sensitivity of erythroid progenitors to erythropoietin
 Polycythemia vera
 Primary familial congenital polycythemia
 Activating mutations of the erythropoietin receptor
Rare; due to altered hypoxia sensing
 von Hippel-Lindau mutations, eg, homozygous R200W mutation (Chuvash polycythemia)
EGLN1 mutations (proline hydroxylase domain protein 2)
EPAS1 mutations (hypoxia-inducible factor 2 alpha)
Secondary erythrocytosis
Physiologically appropriate with increased erythropoietin
 High-altitude erythrocytosis
 Cardiac and pulmonary disease characterized by hypoxia
 Hypoventilation syndromes
 Chronic carbon monoxide poisoning
 Congenital methemoglobinemia
 Secondary familial congenital polycythemia
HBA1, HBA2, HBB mutations (high-oxygen-affinity hemoglobin)
 Mutations of the BPGM (bisphosphoglycerate) gene
Physiologically inappropriate with increased erythropoietin
 Androgen abuse
 Erythropoietin abuse
 Postrenal transplant erythrocytosis
 Ectopic secretion of erythropoietin by neoplasms such as renal cell carcinoma, hepatocellular carcinoma, hemangioblastoma, pheochromocytoma, uterine leiomyomata