Application of the assay of urine FSH β-subunit in patients with pubertal disorders

Objective: To evaluate the diagnostic predictive value in the identification of puberty disorders by means of ELISA of β-FSH subunit levels in successively collected urine samples compared to RIA of intact FSH in serum obtained from the normal control subjects and patients with puberty disorders, respectively.Subjects and Methods: Five male and four female volunteers were recruited as controls. Four patients with the hypogonadotropic hypogonadism, five patients with hypergonadotropic hypogonadism, four patients with the central precocious puberty and one patient with isosexual peripheral precocious puberty collected successively their early-morning urine samples for 30 to 32 days.The urine β-FSH subunit was assayed with the method of ELISA, then adjusted by creatinine (Cr) concentration.Results:Comparing with their cotemporary groups, patients with the hypogonadotropic hypogonadism had lower levels of urine β-FSH, and patients with idiopathic hypergonadism had higher levels with irregular fluctuation. Meanwhile, patients with the central precocious puberty had much higher levels of urine β-FSH with irregular peaks, and patients with isosexual peripheral precocious puberty had almost normal levels. The patterns were coincident with the clinical characteristics and serum FSH levels.Conclusion: The ELISA of urine β-FSH subunit possesses a number of advantages over the RIA of serum FSH level, such as low cost, simplicity and reliability in the clinical practice. It can be used for the diagnoses of puberty disorders. In addition, it is possible and much easier, comparing with blood samples, to collect successively urine samples for research of pathophysiological dynamics of FSH secretion in puberty disorders and other reproductive dysfunction.