Evaluation of fibronectin 1 in one dried blood spot and in urine after rhGH treatment.

Since the appearance of recombinant human growth hormone (rhGH) in the 1980s, its expansion and acquisition through the black market has increased, so the detection of its abuse continues to be a challenge. New biomarkers that are more reliable and sensitive, allowing a larger detection window, are still needed. In this line, Fibronectin 1 (FN1) has been proposed as a potential genetic and protein biomarker of rhGH abuse in peripheral blood lymphocytes, serum, and plasma. However, logistic problems associated with current blood collection in sports drug testing point towards potential new alternative matrices that could be good candidates to be evaluated. Results obtained in this study showed high ELISA FN1 levels in one dried blood spot and in urine samples in ten healthy male volunteers treated with rhGH. Results showed that especially dried blood spots appear as a potential good matrix to detect rhGH abuse by means of FN1 biomarker.