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 patientswith CYP21 deficiency over long-term periods, whereas urinary pregnanetriol (PT) for 24 hhas been used as an index for short-term periods. We previously reported that the range of1.2–2.1 mg/m²/day of PT for 24 h (24-h PT) could be used as an index of optimalcontrol in patients with CYP21 deficiency. The purpose of this study was to analyze therange of PT in the first morning urine samples (morning PT) as an index of optimal controlin patients with CYP21 deficiency. First, the therapeutic periods of 15 participants (aged2 yr and 5 mo to 17 yr and 4 mo) were classified into excessive, good or poor controlperiods using auxological data and Cushing-like symptoms, and 24-h PT levels were analyzedin each period, retrospectively. The 95% confidence intervals for the means of 24-h PTlevels 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 PTlevels collected on the same day were analyzed for 14 participants (aged 9 mo to 29 yr and8 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, wasadjusted by the correlation, the ideal morning PT range became 2.15–3.34 mg/gCr. Inconclusion, a morning PT in the range of 2.2–3.3 mg/gCr can be used as an index of optimalcontrol in patients with CYP21 deficiency.