HOME MONITORING OF 17-ALPHA-HYDROXYPROGESTERONE LEVELS BY FILTER-PAPER BLOOD SPOTS IN PATIENTS WITH 21-HYDROXYLASE DEFICIENCY

21-Hydroxylase (21-OH) deficiency is characterized by an excess of and rogen in both sexes and premature skeletal maturation resulting in sho rt adult stature and male infertility. To achieve optimal height in ch ildren and fertility in adults, the replacement treatment of 21-OH def iciency with glucocorticoids should be regulated in order to adequatel y reduce the excess of androgens while minimizing the dose of glucocor ticoids required. Neonatal screening for 21-OH deficiency is based on the measurement of the 17 alpha-hydroxyprogesterone (17-OHP) level fro m blood spotted on filter paper. The aim of this study was to examine whether repeated daily blood sampling on filter paper can assist in im proving the monitoring of, and compliance to, 21-OH deficiency treatme nt. Methods: During a 5-year period (1989-1994) we instructed 8 patien ts with 21-OH deficiency (2 males with salt losing, 2 males and 1 fema le simple virilizing, and 1 male and 2 females with nonclassical 21-OH deficiency) aged 1.3-36 years to sample blood on filter papers 1-4 ti mes a day and send the papers to our neonatal screening laboratory by mail. On 62 occasions we measured both serum and filter paper 17-OHP l evels in order to assess the degree of correlation between the two met hods. Results: Comparison between the filter paper and serum 17-OHP le vels showed a correlation coefficient of r = 0.87. The filter paper le vels were almost always higher than the serum levels. The serum 17-OHP levels were <1 ng/ml whenever the filter paper levels were <3 ng/ml. On long-term follow-up of 17-OHP filter paper levels we observed major diurnal and day-to-day fluctuations which might not have been noticed on routine follow-up clinic visits. Conclusions: Filter paper follow- up of 17-OHP levels can assist in optimizing the replacement treatment in patients with 21-OH deficiency while reinforcing compliance and de creasing the need for frequent clinic visits and hospitalizations. By adjusting the glucocorticoid type, dose, and time of administration to each patient we should be able to achieve optimal growth without bone age acceleration in children, to avoid overtreatment, and to improve fertility in adults.