NEW DECISION LIMITS AND QUALITY-CONTROL MATERIAL FOR DETECTING HUMAN CHORIONIC-GONADOTROPIN MISUSE IN SPORTS

Male athletes may administer human chorionic gonadotropin (hCG) to enh ance performance. Despite imposing a ban on hCG doping, the Internatio nal Olympic Committee has no recommended procedure to confirm the pres ence of hCG. Our aim was to establish a limit for hCG in urine above w hich a sample may be considered positive. We measured hCG concentratio ns in urine samples from 1400 men with the Serono MAIAclone IRMA. Stat istical evaluation of the results gave a ''far outside'' value [75th p ercentile + (3 x interquartile range)] of 5.0 IU/L; greater values are extremely unusual. Immunoreactive material in urine samples from a re ference group of 120 noncompeting individuals was concentrated about s evenfold by centrifugal ultrafiltration; all these concentrated sample s gave assay values <5.0 IU/L. To ensure with the greatest possible de gree of certainty that no false-positive result is reported, we propos e a decision limit of 10 IU/L in nonconcentrated ultrafiltered samples . We also prepared quality-control material to contain hCG at 10 IU/L. This material provides a decision limit above which, after confirmato ry procedures, a sample should be considered positive. This should hel p establish comparability of results among laboratories testing for sp orts drugs.