Impact of a change to a novel chemiluminescent immunoassay for measuring plasma aldosterone on the diagnosis of primary aldosteronism

Endocr J. 2023 Feb 16. doi: 10.1507/endocrj.EJ22-0585. Online ahead of print.ABSTRACTIn Japan, the standard method for measuring plasma aldosterone concentration (PAC) for primary aldosteronism (PA) diagnosis was changed from radioimmunoassay (RIA) to a novel chemiluminescent enzyme immunoassay (CLEIA). The purpose of this study is to simulate the possible impact of the change on PA diagnosis. This retrospective study assessed 2,289 PA patients. PACs measured by conventional RIA were transformed to estimated PACs (CLEIA) as follows: RIA (pg/mL) = 1.174 × CLEIA (pg/mL) + 42.3. We applied the estimated PAC (CLEIA) to the conventional cut-off of aldosterone-to-renin activity ratio ≥200 for screening and captopril challenge test (CCT) and PAC ≥60 pg/mL for saline infusion test (SIT). Application of the estimated PAC to screening and confirmatory tests decreased the number of PA diagnoses by 36% (743/2,065) on CCT and 52% (578/1,104) on SIT (discrepant cases). Among the discrepant cases, 87% (548/628) of CCT and 87% (452/522) of SIT were bilateral on adrenal venous sampling (AVS). Surgically treatable aldosterone-producing adenomas (APAs) were observed in 6% (36/579) and 5% (23/472) of discrepant cases on CCT and SIT, respectively; most were characterized by hypokalemia and/or adrenal nodule on CT imaging. Application of the PAC measured by the novel CLEIA to conventional cut-offs decreases the number of PA diagnoses. Although most discrepant cases were bilateral on AVS, ther...

Source: Endocrine Journal - February 15, 2023 Category: Endocrinology Authors: Hiroki Kobayashi Yoshihiro Nakamura Masanori Abe Akiyo Tanabe Masakatsu Sone Takuyuki Katabami Isao Kurihara Takamasa Ichijo Mika Tsuiki Shoichiro Izawa Norio Wada Takashi Yoneda Katsutoshi Takahashi Kouichi Tamura Yoshihiro Ogawa Nobuya Inagaki Koichi Ya Source Type: research