1992 Volume 21 Issue 2 Pages 138-142
Screening for congenital adrenal hyperplasia due to 21-hydroxylase deficincy in newborns is commonly accomplished in Japan by measuring 17 a-hydroxyprogesterone (17-OH-Δ4P) levels in blood impregnated on filter paper with enzymelinked immunosorbent assay (ELISA).
We found that some of the screening tests for 17-OH-Δ4P used have been influenced by the temperature at which the immuno-reaction of ELISA is performed. When filter paper blood specimens obtained from neonates were tested at lower immuno-reaction temperatures. significantly increased mean 17-OH-Δ4P values were obtained. This phenomenon was observed for screening tests using two commercially available kits and also for an assay system in which antiserum raised in a rabbit against 17-OH-Δ4P -bovine serum albumin (BSA) was used.
17 α-hydroxypregnenolone-3-sulfate (17-OH-Δ5P-S) is known to be abundant in the blood of newborns, and the antisera employed in the ELISAs noted above have weak affinity for this steroid. Therefore, cross-reactivity of 17-OH-Δ5P-S was determined at various immuno-reaction temperatures using 17-OH-5P-S standard filter paper specimens prepared from steroid-free blood.
The correlation between 17-OH-Δ4Plevels obtained by ELISAs for neonates specimens and immuno-reaction temperatures used may be attributable to variation in cross-reactivity of the 17-OH-Δ5P-S contained in the blood of neonates to antibodies used in the ELISAs.
