Analytical evaluation and bioclinical validation of new aldosterone and renin immunoassays

Clin Chem Lab Med. 2022 Sep 13;60(11):1763-1771. doi: 10.1515/cclm-2022-0576. Print 2022 Oct 26.

Abstract

Objectives: Aldosterone and renin determinations play an important role in the etiological diagnosis of secondary hypertension. The analytical performances of new aldosterone and renin immunoassays on the Lumipulse G600II® system (Fujierbio) were investigated and compared with those of the iSYS® system (IDS) on patients concerned by medical investigations in a context of suspected or proven Primary aldosteronism.

Methods: By using the Lumipulse® G Aldosterone and Renin assays we performed imprecision study, linearity and method comparison (n=107). Accuracy of this new renin assay was tested using the International Standard (WHO IS 68/356). We also assessed the equivalence of the different samples types (n=29).

Results: The imprecision evaluation showed all CVs <3% and <6% for Lumipulse® G Aldosterone and Renin assays respectively. The linearity was excellent over the clinical range and the comparison with the iSYS® assays (n=79) showed a strong correlation (R2=1) despite a slight tendency to underestimation (bias of -17.53 pg/mL or 48.56 pmol/L for aldosterone and -15.395 pg/mL for renin). Moreover, the contingency studies based on diagnostic criteria showed that Lumipulse® G results lead to the same clinical diagnosis that iSYS® results. A clear correlation was obtained between EDTA and heparin plasma as well as with the serum for all range of measures.

Conclusions: The Lumipulse® G Aldosterone and Renin assays present performances compatible with a routine use in medical laboratories. The precise quantification in the low range can be of interest in some clinical contexts especially standing/laying tests. However, the standardisation against the WHO International Standard Renin would be advisable.

Keywords: aldosterone; hypertension; immunoassay; primary aldosteronism; renin.

MeSH terms

  • Aldosterone
  • Edetic Acid
  • Heparin
  • Humans
  • Hyperaldosteronism* / diagnosis
  • Hypertension*
  • Immunoassay / methods
  • Renin

Substances

  • Aldosterone
  • Heparin
  • Edetic Acid
  • Renin