Urinary beta-luteinizing hormone and beta-follicle stimulating hormone immunoenzymometric assays for population research

Objective: We developed assays for measurement of urinary beta LH and beta FSH under collection and storage conditions typical of non-clinical research settings. Design and methods: IEMAs for free beta LH and total beta FSH were validated by standard methods. Stability of urinary beta LH and beta FSH was tested across freeze-thaws and stored long term at 4 degrees C or -20 degrees C, or short term at room temperature, and with heating to dissociate the subunits. Results: The IEMAs exhibited acceptable parallelism, specificity, recovery (averaging 100% for beta LH, 97% for beta FSH), imprecision (maximum within-run and between run CVs, respectively, 4.8% and 25.7% for OLH, 5.6% and 17.0% for beta FSH), and minimum detectable dose (2.5 pmol/L for beta LH, 6.8 pmol/L for beta FSH). Urine and serum measures were highly correlated (r=0.95 for LH, 0.86 for FSH). There was no consistent decline with any storage type. Dissociation of subunits by heating was needed for beta LH, but not beta SH. Conclusion: These IEMAs measure free beta LH and total beta FSH, overcoming inter-individual variability in, and collection and storage effects oil, subunit dissociation, without the need for urine preservatives. (c) 2006 The Canadian Society of Clinical Chemists. All rights reserved.