Specimen Type: Serum
Container: 1 Serum Separator Tube (SST)
Preferred Vol: 1.00 mL
Min Vol: 0.50 mL
Tuesday - Saturday
Due to diurnal variation, it is recommended that specimens be collected between 7:30 am and noon.
Erythropoietin is produced primarily by the kidney. Renal production of EPO is regulated by changes in oxygen availability. Under conditions of hypoxia, the level of EPO in the circulation increases and this leads to increased production of red blood cells. Primary polycythemias, or polycythemia vera, are caused by EPO-independent growth of erythrocytic progenitors from abnormal bone marrow stem cells and in most cases decreased levels of EPO are found in these patients. Conversely, various types of secondary polycythemias are associated with the production of elevated levels of EPO. The overproduction of EPO may be an adaptive response associated with conditions that produce tissue hypoxia, such as living at a high altitude, chronic obstructive pulmonary disease, cyanotic heart disease, sleep apnea, high oxygen affinity hemoglobinopathy, smoking, or localized renal hypoxia. In other instances, elevated EPO levels are the result of production by neoplastic cells. Cases of increased EPO have been reported in patients with renal carcinomas, polycystic kidney disease, Wilm's tumors, hepatomas, liver carcinomas, hemangioblastomas, adrenal gland tumors and leiomyomas.