title: Prospective validation of an automated chemiluminescence-based assay of renin and aldosterone for the work-up of arterial hypertension.
abstract: BACKGROUND
  The availability of simple and accurate assays of plasma active renin (DRC) and aldosterone concentration (PAC) can improve the detection of secondary forms of arterial hypertension. Thus, we investigated the performance of an automated chemiluminescent assay for DRC and PAC in referred hypertensive patients.
  
  
  METHODS
  We prospectively recruited 260 consecutive hypertensive patients referred to an ESH Center for Hypertension. After exclusion of six protocol violations, 254 patients were analyzed: 67.3% had primary hypertension, 17.3% an aldosterone producing adenoma (APA), 11.4% idiopathic hyperaldosteronism (IHA), 2.4% renovascular hypertension (RVH), 0.8% familial hyperaldosteronism type 1 (FH-1), 0.4% apparent mineralocorticoid excess (AME), 0.4% a renin-producing tumor, and 3.9% were adrenalectomized APA patients. Bland-Altman plots and Deming regression were used to analyze results. The diagnostic accuracy (area under the curve, AUC of the ROC) of the DRC-based aldosterone-renin ratio (ARRCL) was compared with that of the PRA-based ARR (ARRRIA) using as reference the conclusive diagnosis of APA.
  
  
  RESULTS
  At Bland-Altman plot, the DRC and PAC assay showed no bias as compared to the PRA and PAC assay. A tight relation was found between the DRC and the PRA values (concordance correlation coefficient=0.92, p<0.0001) and the PAC values measured with radioimmunoassay and chemiluminescence (concordance correlation coefficient=0.93, p<0.001). For APA identification the AUC of the ARRCL was higher than that of the ARRRIA [0.974 (95% CI 0.940-0.991) vs. 0.894 (95% CI 0.841-0.933), p=0.02].
  
  
  CONCLUSIONS
  This rapid automated chemiluminescent DRC/PAC assay performed better than validated PRA/PAC radioimmunoassays for the identification of APA in referred hypertensive patients.
authors.forename: Gian Paolo
authors.initials: GP
authors.lastname: Rossi
authors.forename: Giulio
authors.initials: G
authors.lastname: Ceolotto
authors.forename: Giacomo
authors.initials: G
authors.lastname: Rossitto
authors.forename: Teresa Maria
authors.initials: TM
authors.lastname: Seccia
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Maiolino
authors.forename: Chiara
authors.initials: C
authors.lastname: Berton
authors.forename: Daniela
authors.initials: D
authors.lastname: Basso
authors.forename: Mario
authors.identifier: http://orcid.org/0000-0002-0270-1711
authors.initials: M
authors.lastname: Plebani
mesh_terms: D000328:Adult; D000450:Aldosterone / Q000097:blood*; D001331:Automation; D005260:Female; D006801:Humans; D006973:Hypertension / Q000097:blood* / Q000175:diagnosis; D049449:Luminescence; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012083:Renin / Q000097:blood*
chemical_list: D000450:Aldosterone; D012083:Renin