Immunoprocedures for detecting human chorionic gonadotropin: clinical aspects and doping control

Area of Science:

• Endocrinology
• Biochemistry
• Sports Science

Background:

• Human chorionic gonadotropin (hCG), a key pregnancy hormone, is detectable at low levels in men and non-pregnant women.
• hCG exists in multiple molecular forms, including intact heterodimers, cleaved forms, free subunits, and fragments, particularly prevalent in urine.

Purpose of the Study:

• To investigate the molecular forms of hCG present in biological samples.
• To assess the implications of hCG molecular heterogeneity for immunoassay standardization and interpretation.
• To evaluate the detection period and challenges of hCG use in doping control.

Main Methods:

• Analysis of hCG immunoreactivity in plasma and urine.
• Characterization of different hCG molecular forms.
• Assessment of hCG detection following exogenous administration.

Main Results:

• Proteolytic fragments significantly contribute to hCG immunoreactivity in urine.
• Various hCG forms exhibit differential cross-reactivity in immunoassays, complicating standardization.
• Exogenous hCG administration results in detectable levels in serum and urine for 7-11 days.

Conclusions:

• The heterogeneity of hCG molecular forms presents a significant challenge for accurate and standardized quantitative determinations, especially in urine.
• Careful consideration is required when using immunoassays for hCG urine analysis, particularly in the context of doping control.
• Further validation of assays for urine sample analysis is necessary to ensure reliable doping control results.