Objective: To determine the prognostic value of seminal plasma volume, pH, fructose, and alpha-glucosidase for the detection of cystic fibrosis transmembrane conductance regulator (CFTR) gene mutations.
Design: Retrospective data analysis.
Setting: University infertility clinic (referral center).
Patient(s): Fifty-nine men with obstructive azoospermia.
Intervention(s): Semen analysis including seminal plasma volume, pH, fructose, alpha-glucosidase, molecular genetic diagnosis of CFTR mutations and FSH measurement.
Main outcome measure(s): Sensitivity and specificity of seminal plasma markers for the detection of CFTR mutations.
Result(s): A CFTR mutation was detected in 26 of 59 patients with obstructive azoospermia. Patients carrying a mutation had significantly lower seminal plasma volume (mean +/- SEM: 1.5 +/- 1.4 mL vs. 2.8 +/- 2.2 mL), lower pH levels (25th percentile, median, 75th percentile: 6.5, 6.8, 7.5 vs. 7.7, 7. 9, 7.9) and lower fructose content (1.0, 1.1, 3.7 vs. 5.8, 20.0, 83. 0 micromol/ejaculate) than those without mutations. Diagnostic efficacy for detection of mutations was best (pH 81.4%, fructose 81. 8%) at a cutoff level for pH of 7.4 and fructose of 2 micromol/ejaculate.
Conclusion(s): Seminal plasma markers provide an effective, noninvasive method to predict CFTR mutations in men with obstructive azoospermia.