Evaluation of automated sex hormone binding globulin immunoassays

BACKGROUND: Sex hormone binding globulin (SHBG) is an important regulator of testosterone and estradiol. STUDY DESIGN: We validated the Diagnostic Products Corporation (DPC) and Roche Diagnostic SHBG immunoassays on the DPC Immulite 2000 and Roche Modular E170 analyzers. RESULTS: The coefficient of variation for SHBG kits from both manufacturers was in the range of 3.9-7.7% (between-run) and 0.95-5.0% (within-run), free of interference from hemoglobin, bilirubin, lipid, and rheumatoid factor, and linear up to at least 170 nM SHBG. The results of the two methods, however, were biased by up to 29% depending on the SHBG concentration. CONCLUSION: The SHBG assays perform well but standardization is needed.