Assay reproducibility and within-person variation of Müllerian inhibiting substance

ObjectivesTo assess reproducibility of a commercial müllerian inhibiting substance (MIS) assay and evaluate within-person variation in serum MIS levels.DesignAssay reproducibility was evaluated by measuring MIS in multiple serum aliquots from the same blood collection. Within-person variation was assessed by measuring MIS in serum collected twice from the same individuals.SettingCancer Prevention Biomarker and Genotyping Facility, fox Chase Cancer Center, Philadelphia, Pennsylvania.Patient(s)Assay reproducibility was evaluated using serum from five volunteers with regular menstrual cycles. Within-person variation was evaluated in serum from 20 premenopausal women who donated blood twice at least 1 year apart.Intervention(s)For both studies, samples were randomly ordered in batches and laboratory personnel were blinded to which aliquots were from the same subject.Main Outcome Measure(s)The MIS was measured by ELISA.Result(s)Within- and between-batch coefficients of variation (CVs) of the assay were 7.9% and 12.3%, respectively. After deleting one subject with extreme values, these CVs decreased to 7.6% and 7.7%, respectively. Within- and between-subject variance in MIS measurements were 2.19 and 0.31, respectively, and the intraclass correlation coefficient was 0.88 (95% confidence interval .77–.98).Conclusion(s)The MIS serum concentration is relatively stable over 1 year in premenopausal women and can be measured with good reproducibility using a commercial kit.