Growth Hormone Abuse and Biological Passport: Is Mannan-Binding Lectin a Complementary Candidate?

Abstract

In the detection of human growth hormone (GH) abuse, the approach based on altered GH-related biomarkers is also being considered with respect to its application within the context of a biological passport. As a potential biomarker, mannan-binding lectin (MBL), which is reported to respond to recombinant GH (rGH) administration, is evaluated here. Randomized and single blind and approved by the Ethical Committee (Comité Ético de Investigación Clínica-Instituto Municipal de Asistencia Sanitaria). One group of 12 male subjects (24.2 ± 2.2 years; 76.1 ± 6.1 kg) was studied. Mannan-binding lectin concentration was measured in 12 healthy individuals after subcutaneous daily doses of 6 IU of rGH administration. Mannan-binding lectin serum concentration increased after rGH administration. Mannan-binding lectin concentration increases were observed 48 hours after the first administration and remained elevated for several days after the final dose. Mannan-binding lectin concentration increase and elapsed time to recover initial MBL values after the last rGH administration. Absolute values displayed high interindividual variability, and 1 individual did not show any MBL increase (potential MBL deficiency). Mannan-binding lectin protein showed a clear concentration increase after continued rGH administration, despite the high heterogeneity found between individuals. The use of MBL as a complementary GH-related biomarker could be of interest, taking advantage of the high increases (up to 700%) and the relatively slow recovery time.