title: Assessment of Leydig and Sertoli cell functions in infants with nonmosaic Klinefelter syndrome: insulin-like peptide 3 levels are normal and positively correlated with LH levels.
abstract: BACKGROUND
  Klinefelter syndrome (KS) is the most common sex chromosome disorder and a major cause of male infertility. In adult patients, serum inhibin B and anti-Mullerian-hormone (AMH) are undetectable, testosterone secretion is often impaired, and the tubules are depleted of germ cells. Before puberty, inhibin B, AMH, and testosterone levels are within the normal range.
  
  
  OBJECTIVE
  Sertoli and Leydig cell secretions, including insulin-like peptide-3 (INSL3), were evaluated in infants with nonmosaic XXY karyotype to assess testicular function soon after birth.
  
  
  METHODS
  The study was conducted in four University Pediatric Departments from the United States and France.
  
  
  METHODS
  Sixty-eight prenatally diagnosed infants aged 2-750 d were enrolled.
  
  
  METHODS
  Serum FSH, LH, inhibin B, AMH, and INSL3 were measured by immunoassay, and testosterone was measured by tandem mass-spectrometry.
  
  
  RESULTS
  In infants with KS, INSL3 levels transiently increased at 2-3 months of age and were significantly correlated with testosterone (Spearman r = 0.57) and LH (Spearman r = 0.73) levels. They did not differ from controls. Testosterone levels were within the normal range, but most of them were below the median of controls. Inhibin B and AMH levels were also within normal range. Inhibin B was correlated with FSH (Spearman r = 0.49). AMH was not correlated with FSH or testosterone. FSH levels were above normal in 25% of patients, despite normal inhibin B levels.
  
  
  CONCLUSIONS
  In infants with KS, Leydig cells are normally sensitive to the LH proliferative effect. In contrast, the Sertoli cell sensitivity to FSH is questionable, which may be prophetic of the postpubertal Sertoli cell resistance to FSH.
authors.affiliation: Department of Pediatric Endocrinology, Hôpital Armand-Trousseau, Assistance Publique-Hôpitaux de Paris, Pierre and Marie Curie University, 75012 Paris, France.
authors.forename: Sylvie
authors.initials: S
authors.lastname: Cabrol
authors.forename: Judith L
authors.initials: JL
authors.lastname: Ross
authors.forename: Ilene
authors.initials: I
authors.lastname: Fennoy
authors.forename: Claire
authors.initials: C
authors.lastname: Bouvattier
authors.forename: Marc
authors.initials: M
authors.lastname: Roger
authors.forename: Najiba
authors.initials: N
authors.lastname: Lahlou
mesh_terms: D054304:Anti-Mullerian Hormone / Q000032:analysis / Q000097:blood; D002675:Child, Preschool; D015331:Cohort Studies; D003940:Diagnostic Techniques, Endocrine; D005640:Follicle Stimulating Hormone / Q000032:analysis / Q000097:blood; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007265:Inhibins / Q000032:analysis / Q000097:blood; D007328:Insulin / Q000032:analysis / Q000097:blood*; D007713:Klinefelter Syndrome / Q000097:blood* / Q000175:diagnosis / Q000235:genetics / Q000503:physiopathology*; D007985:Leydig Cells / Q000502:physiology*; D007986:Luteinizing Hormone / Q000032:analysis / Q000097:blood*; D008297:Male; D009030:Mosaicism; D011506:Proteins / Q000032:analysis; D012708:Sertoli Cells / Q000502:physiology*; D013739:Testosterone / Q000032:analysis / Q000097:blood
chemical_list: D007328:Insulin; C084797:Leydig insulin-like protein; D011506:Proteins; C422364:inhibin B; D013739:Testosterone; D007265:Inhibins; D054304:Anti-Mullerian Hormone; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone