According to investigators at the University of Western Ontario, London, Ontario, Canada, erythropoietin (EPO) levels are generally elevated in elderly individuals with anemia of unknown etiology (AUE), but remain inappropriately low when compared to anemia of other etiologies, suggesting either a relative EPO deficiency, an abnormal EPO response, or an abnormal erythroid cell response to EPO. The researchers presented their poster at ASH, held in December in New Orleans.
They conducted a systematic review of observational studies. For inclusion into the final review, studies needed to report data on EPO levels in elderly individuals diagnosed with anemia of unknown etiology. The investigators identified 4277 potentially relevant citations, of which 31 studies they reviewed in full and seven cohort studies (two retrospective, five prospective) they included in the final review. The studies involved 2534 participants and, in general, found lower EPO levels in AUE compared with iron deficiency anemia and other forms of anemia; a lack of correlation between EPO levels and the severity of anemia; and EPO levels in AUE that are in general higher than in non-anemic patients.