The Range of 2.2–3.3 mg/gCr of Pregnanetriol in the First Morning Urine Sample as an Index of Optimal Control in CYP21 Deficiency

Auxological data are the gold standard indexes of the therapeutic conditions in patients with CYP21 deficiency over long-term periods, whereas urinary pregnanetriol (PT) for 24 h has been used as an index for short-term periods. We previously reported that the range of 1.2-2.1 mg/m(2)/day of PT for 24 h (24-h PT) could be used as an index of optimal control in patients with CYP21 deficiency. The purpose of this study was to analyze the range of PT in the first morning urine samples (morning PT) as an index of optimal control in patients with CYP21 deficiency. First, the therapeutic periods of 15 participants (aged 2 yr and 5 mo to 17 yr and 4 mo) were classified into excessive, good or poor control periods using auxological data and Cushing-like symptoms, and 24-h PT levels were analyzed in each period, retrospectively. The 95% confidence intervals for the means of 24-h PT levels in the excessive, good and poor control periods were 0.24-2.24 (n=25), 2.88-4.92 (n=114) and 13.26-21.28 (n=72) mg/gCr, respectively. Subsequently, 24-h PT and morning PT levels collected on the same day were analyzed for 14 participants (aged 9 mo to 29 yr and 8 mo). There was a significant correlation between the above two PT levels (n=25, p<0.0001). When the 24-h PT range of the good control period, 2.88-4.92 mg/gCr, was adjusted by the correlation, the ideal morning PT range became 2.15-3.34 mg/gCr. In conclusion, a morning PT in the range of 2.2-3.3 mg/gCr can be used as an index of optimal control in patients with CYP21 deficiency.