Does variant luteinizing hormone (V-LH) predispose to improper testicular position in late pregnancy?
Undescended testes are a common urogenital malformation affecting 2-9% of newborn boys. The etiology of cryptorchidism is probably heterogeneous, but insufficient androgen effect has been recognized as one cause of the condition. A common genetic variant (V) form of LH occurs in apparently healthy individuals universally. Compared with wild-type (WT) LH, the V-LH molecule has increased bioactivity in vitro but shorter half-life in vivo. In the present study, we screened 93 cryptorchid (59 uni- and 34 bilateral) and 211 healthy boys for the occurrence of V-LH to evaluate whether it is related to testicular descent. Two immunofluorometric assays with different combinations of MAb, one detecting WT-LH, the other detecting both WT- and V-LH, were used to measure LH concentrations. The ratio of two LH measurements was used to assess the V-LH status. The prevalence of V-LH was similar in the control and cryptorchid groups, and the total prevalence of V-LH corresponded well to the prevalence of V-LH in general Finnish population. Among cryptorchid boys, the prevalence of V-LH was dependent on gestational age: 6.7% at GA <37, 20.9% at GA 37-39, and 42.9% at GA of 40-42 wk. In contrast, the percentage of V-LH status was similar at different gestational ages in all control groups. We conclude that V-LH is not critical for normal testicular descent but the increased prevalence of V-LH among cryptorchid boys with GA >40, suggests that the lower hormonal efficacy of V-LH predisposes for improper testicular descent in late pregnancy.
Kaleva
Marko
M
Department of Physiology, University of Turku, Finland. marko.kaleva@utu.fi
Virtanen
Helena
H
Haavisto
Anne-Maarit
AM
Main
Katharina
K
Skakkebaek
Niels E
NE
Huhtaniemi
Ilpo
I
Irjala
Kerttu
K
Toppari
Jorma
J
D003456:Cryptorchidism / Q000503:physiopathology*; D005260:Female; D005455:Fluorescent Antibody Technique; D006801:Humans; D007986:Luteinizing Hormone / Q000502:physiology*; D008297:Male; D011247:Pregnancy / Q000502:physiology*; D013737:Testis / Q000033:anatomy & histology*
D007986:Luteinizing Hormone