OR37-2 The Diagnostic Value of First-Voided Urinary LH compared with GnRH-stimulated gonadotropins in Differentiating Slowly-Progressive From Rapidly Progressive-Precocious Puberty in girls

Program: Abstracts - Orals, Featured Poster Presentations, and Posters
Session: OR37-Pediatric Endocrinology: HPG Axis Disorders
Clinical
Monday, June 17, 2013: 11:15 AM-12:45 PM
Presentation Start Time: 11:30 AM
Room 102 (Moscone Center)
Amnon Zung*, Ella Burundukov, Mira Ulman, Tamar Glaser, Moshe Rosenberg, Malka Chen and Zvi Zadik
Kaplan Medical Center, Rehovot, Israel
Context Characterization of pubertal progression is required to prevent unnecessary intervention in unsustained or slowly-progressive (SP) precocious puberty (PP), while delivering hormonal suppression in rapidly-progressive (RP) PP. GnRH stimulation is considered the gold-standard test for diagnosing PP, whereas first-voided urinary LH (ULH) was suggested as a non-invasive methods, assuming that it reflects the nocturnal arousal of LH peaks at the onset of puberty.

Objective We aimed to assess the diagnostic value of ULH compared with GnRH-stimulated gonadotropins in differentiating SP- from RP-PP.

Design, setting and participants 62 girls with PP underwent both GnRH stimulation and ULH assay. Fifteen girls with peak LH>10 IU/L (i.e. advanced puberty) started treatment immediately whereas other 47 girls were evaluated after 6 months for pubertal advancement, height acceleration and bone-age maturation. Based on these criteria, the participants were assigned to 5 subgroups: pubertal regression, no progression or progression by one, two or three criteria. The first three subgroups were defined as SP-PP (n=29) while the other subgroups (including advanced puberty) were defined as RP-PP (n=33). Additional 23 prepubertal girls were evaluated for ULH.

Methods Both serum gonadotropins and ULH were measured by the same immunochemiluminescence assay. A preliminary study was peformed to validate this assay for ULH. Spiking recoveries of ULH ranged from 93% to 115%, functional sensitivity was 0.76 IU/L and intra- and inter-assay variability ranged from 5.2 to 19.5 IU/L and from 4.7 to 9.7 IU/L respectivrly, for a wide range of ULH values.   

Results First voided ULH but not serum gonadotropins could distinguish girls with two and three criteria from less progressive subgroups. By comparison to SP-PP, those with RP-PP had higher basal (0.81±1.43 vs. 0.12±0.05 IU/L; p=0.003) and peak LH (10.90±10.09 vs. 2.78±1.78 IU/L; p<0.001), basal FSH (2.60±2.07 vs. 1.17±0.89), peak LH/FSH ratio (0.98±0.76 vs. 0.22±0.12; p<0.001) and ULH (2.68±1.83 vs. 1.05±0.26 IU/L; p<0.001). Based on ROC analysis, a ULH cutoff of 1.15 IU/L had a better sensitivity (91%) and negative predictive value (88%) than other parameters, with a specificity and positive predictive value of 72% and 79%, respectively. The area under the ROC curve was the largest in ULH curve (0.901).

Conclusion ULH assay is a non-invasive, reliable method that can assist in the distinction between SP- and RP-PP.

Nothing to Disclose: AZ, EB, MU, TG, MR, MC, ZZ

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