Introduction: Rubella is a generally mild viral infection, but it carries the risk of potentially severe complications, especially during pregnancy. Immunity to rubella is determined using commercial chemiluminescent immunoassays, calibrated with international standards. Despite this, discrepancies have been observed in the results obtained by different methods.
Methods: This study evaluates the performance of two chemiluminescent immunoassays (CLIAs) (Alinity i® Rubella IgG and Atellica IM® Rubella IgG) in determining rubella immunity in patient sera with low levels of anti-rubella virus (RV) IgG, using immunoblot (IB) as the reference method.
Results: 101 sera were analyzed, with 72 (71.3%) classified by IB as positive and 28 (27.7%) as negative. Both assays showed 100% specificity, with sensitivity ranging from 15% for Alinity i® to 66% for Atellica IM®. The concordance between IB and CLIA Atellica was 75% when equivocal results were considered negative and 95% when considered positive, whereas for CLIA Alinity, it was 39% and 66%, respectively.
Conclusions: The evaluated CLIA showed discrepancies in determining rubella immunity, highlight inadequate standardisation in the quantification of specific IgG, which could lead to errors in patient management, incorrect classification of immune status, and unnecessary revaccinations in this patient population.
Keywords: Chemiluminescent immunoassay; Embarazo; Immunity; Inmunidad; Inmunoensayo quimioluminiscente; Pregnancy; Rubella; Rubella virus; Rubéola; Rubéola virus.
Published by Elsevier España, S.L.U.