Alere NT-proBNP for Alinity i Reagent Kit

The Alere NT-proBNP for Alinity i is a chemiluminescent microparticle immunoassay (CMIA) that quantitatively measures N-terminal pro B-type natriuretic peptide (NT-proBNP) in human serum and plasma. It is used in emergency departments as an aid in diagnosing heart failure in patients with clinical suspicion of new onset or worsening heart failure.

The subject device uses CMIA technology on the Alinity i system with an analytical measuring interval of 15.8 to 35,000 pg/mL and no hook effect up to 372,620 pg/mL. The predicate uses electrochemiluminescent microparticle immunoassay (ECLIA) technology with a measuring interval of 5 to 35,000 pg/mL and no hook effect up to 300,000 pg/mL. Both measure the same analyte using sandwich immunoassay principles with quantitative results from human serum and plasma.

The submission cites Clinical and Laboratory Standards Institute (CLSI) guidance documents: EP05-A3 (precision), EP06 (linearity), EP17-A2 (lower limits of measurement), EP07 (interference testing), EP28-A3c (reference intervals), and EP12 (qualitative/binary output performance).

Both devices measure identical NT-proBNP analyte using sandwich immunoassay principles from the same specimen types with chemiluminescent detection. Although the subject uses CMIA while the predicate uses ECLIA, both employ comparable two-step immunoassay architectures. Nonclinical performance (precision, linearity, specificity, and reference ranges) demonstrates acceptable analytical performance across the measurement interval. Clinical data from 2,127 emergency department subjects show the subject device achieves similar posttest probabilities and likelihood ratios for HF diagnosis across age groups, with positive and negative cutoffs aligned to clinical need, supporting functional equivalence for the intended use of aiding HF diagnosis in emergency settings.