A single blood sample for stimulated LH assayed by ICMA is useful for monitoring the treatment efficacy of triptorelin depot in girls.

BACKGROUND

There is still no consensus on the optimal monitoring method to evaluate the hypothalamic-pituitary-gonadal axis (HPGA) inhibition.

METHODS

There were 124 girls treated with triptorelin depot due to puberty disorders, including 77 central precocious puberty and 47 early puberty. After treatment, triptorelin stimulation tests were performed, and blood samples were collected at 0, 20, 40 and 60 min. Luteinizing hormone (LH) and follicle-stimulating hormone (FSH) were measured by immunochemiluminometric assay (ICMA).

RESULTS

Peak LH (PLH), peak FSH and estradiol in 124 girls were significantly decreased after treatment, while 2 cases had inadequate treatment efficacy. Areas under the receiver operating characteristic curves (AUC) of PLH and peak FSH after stimulation for the diagnosis of HPGA suppression were 0.984 and 0.121. When the cut-off value of PLH was ≤ 2.25 IU/L, the sensitivity was 96.7% and specificity was 100.0%. There was no difference in AUC between PLH and a single LH at 20, 40, or 60 min (p > 0.05). When LH were ≤ 2.34 IU/L, ≤ 2.21 IU/L and ≤ 2.00 IU/L at 20, 40 and 60 min, respectively, the sensitivity were 99.1%, 96.7% and 98.4%, and the specificity were all 100.0%. The correlation coefficients between PLH and LH at 20, 40 or 60 min were 0.947, 0.975 and 0.961.

CONCLUSION

A single blood sample for stimulated LH at 20 min, 40 min, or 60 min assayed by ICMA during triptorelin stimulation test is useful for monitoring the treatment efficacy of triptorelin depot in girls with puberty disorders.