High-dose hook effect in 17-hydroxyprogesterone assay in a patient with 21-hydroxylase deficiency


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Parlak M., Ellidağ H. Y., Türkkahraman D.

JCRPE Journal of Clinical Research in Pediatric Endocrinology, cilt.7, sa.4, ss.329-332, 2015 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 7 Sayı: 4
  • Basım Tarihi: 2015
  • Doi Numarası: 10.4274/jcrpe.2180
  • Dergi Adı: JCRPE Journal of Clinical Research in Pediatric Endocrinology
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, TR DİZİN (ULAKBİM)
  • Sayfa Sayıları: ss.329-332
  • Anahtar Kelimeler: 17-hydroxyprogesterone, Congenital adrenal hyperplasia, High-dose hook effect, Immunoassay
  • Akdeniz Üniversitesi Adresli: Evet

Özet

© Journal of Clinical Research in Pediatric Endocrinology, Publishedby Galenos Publishing.Congenital adrenal hyperplasia (CAH) describes a group of disorders characterized by enzyme defects in adrenal steroidogenesis. 21-hydroxylase deficiency (21-OHD) is the most commonly encountered form. The analysis of steroids in pediatric cases requires high-sensitivity assays. A 14-yearold Syrian girl was referred for evaluation of short stature, amenorrhea, and hirsutism. On physical examination, breast development was Tanner stage 1. She had a phallic clitoris with a single urogenital orifice. Laboratory findings revealed primary adrenal deficiency with high androgen levels and low levels of 17-hydroxyprogesterone (17-OHP), (<0.05 ng/mL) and estrogen. This unexpected result led to suspicion of a high-dose hook effect. The measurement was repeated after 1/10 dilution of serum, and a high level of 17-OHP (115.4 ng/mL) was detected with the same testenzyme-linked immunosorbent assay (ELISA). Simple virilizing form of CAH (21-OHD) was suspected and confirmed with genetic analysis. After initiation of glucocorticoid therapy, breast development was noted along with a decrease in testosterone level and an increase in estrogen level. To our knowledge, this is the first case report of hook effect for 17-OHP immunoassay in a patient with 21-OHD. High-dose hook effect should be suspected in patients with CAH when the test results are incompatible with one another. Additionally, this case demonstrates that a high testosterone level can block aromatase activity and consequently also estrogen production and breast development.