Preliminary comparative evaluation of an immunofluorescence point-of-care system and central laboratory platforms for
Michela Salvatici1, Francesca Carreras1, Monica Gaimarri1
1UOC Laboratory of Clinical Medicine with Specialized Areas, IRCCS MultiMedica, 20138, Milan, Italy.
Background:
Point-of-care testing (POCT) can accelerate clinical decision-making, but its analytical performance must be verified against central laboratory platforms before implementation. This study compared an immunofluorescence-based POCT system (STANDARD™ F Analyzer, SD Biosensor) with central laboratory analyzers used in the Clinical Laboratory of IRCCS MultiMedica (Siemens Atellica IM and CS-5100) for cardiac Troponin I (cTnI), creatine kinase-MB (CK-MB), N-terminal pro-brain natriuretic peptide (NT-proBNP), D-dimer and high-sensitivity C-Reactive Protein (hs-CRP).
Methods:
Serum and citrate samples were tested in parallel on both systems. Analytical precision was assessed using a CLSI EP15-A3 5 × 3 design. Method comparison included Passing-Bablok regression, Bland-Altman analysis and categorical agreement assessed by Cohen's κ at clinically relevant decision thresholds.
Results:
A total of 217 samples were analyzed. The POCT system met predefined precision acceptance criteria for most biomarkers. Significant inter-method differences were particularly evident for CK-MB and D-dimer, whereas NT-proBNP showed smaller analytical discrepancies. hs-CRP showed acceptable categorical agreement despite limited precision performance at one control level. For cTnI, quantitative comparison at very low concentrations was limited by the higher limit of quantification of the POCT assay. Overall, categorical agreement at clinical decision thresholds ranged from moderate to high across biomarkers.
Conclusion:
The STANDARD™ F Analyzer showed variable analytical performance, with limited analytical comparability to reference methods, particularly for hs-CRP and at low cTnI concentrations. Categorical agreement was moderate overall, but clinically relevant misclassifications were observed. Therefore, the POCT platform may serve as a complementary tool in settings without immediate access to a core laboratory, provided that its analytical limitations are recognized and results are interpreted using assay-specific thresholds.
