P-363: Automated measurement of active renin on the Nichols Advantage®Chemiluminescence System

• Published in: American journal of hypertension 2001-04, Vol.14 (S1), p.152A-152A
• Main Authors: Hall, Shelby J., Gonzalez, Elizabeth, Mokhtari, Azita, Desai, Vijay, Sundaram, Subramaniam
• Format: Article
• Language: English
• Subjects: Active Renin; Automated; Chemiluminescence
• ISSN: 0895-7061; 1941-7225; 1879-1905
• DOI: 10.1016/S0895-7061(01)01959-8

We have developed an automated chemiluminescent immunoassay for quantitating renin in plasma specimens, to be performed on the Nichols Advantage® Specialty System. This assay measures renin directly, is easier to standardize against the WHO reference material (from kidney), and is less labor-intensive than the classical enzyme kinetic PRA and PRC assays. Since the non-proteolytic activation of prorenin is time and temperature dependent, we attempted to minimize this activation by shortening the incubation time (30 min) and raising the incubation temperature to 37°C. Blood samples from normal subjects were obtained during standardized upright and supine positions, and the samples were processed at room temperature to avoid cryoactivation. Results indicate that the renin levels were significantly lower in supine than upright condition. This assay measures renin from 2 to 500 μU/mL with an analytical sensitivity of 1 μU/mL. The assay has no high dose hook for specimens with renin concentrations up to 100,000 μU/mL. Recovery values obtained by serial dilution of EDTA plasma samples were between 87 - 100% across PRA concentrations of 5 - 57 ng/mL/hr. Intra-assay variation of >3 μU/mL is 5%, and inter-assay variation at >3 μU/mL is