[Analytical performances of SPAPLUS® turbidimeter for the dosage of immunoglobulins and beta-2 microglobulin in serum].

We evaluated the analytical performances of the SPAPLUS(®) immunoturbidimeter assays manufactured by The Binding Site(®) for the quantification of thirteen immunological parameters in serum: IgG, IgA, IgM and IgD immunoglobulins, IgG subclasses (1 to 4), IgA subclasses (1 and 2), beta-2 microglobulin, free light chains kappa and lambda. The within-day precision (repeatability) and the between-day precision (reproducibility) were obtained for two or three concentration levels depending of the parameter and were below the recommendations of the manufacturer, except for the repeatability of IgG1 (at a level of concentration of 6.7 g/L). An agreement above 90% (with Bland and Altman analysis) was observed between the results obtained with SPAPLUS(®) and those obtained with the nephelometer IMMAGE(®) 800 or radial immunodiffusion. The evaluation confirmed the linearity of the assays and the absence of contamination for all the parameters tested. We also assessed the practicability of the SPAPLUS(®) in terms of maintenance, frequency of calibration and cadence tests. The SPAPLUS(®) immunoturbidimeter displays good analytical performances for the immunological parameters evaluated in the present work.