Accuracy, precision, and consistency of methods for pathogen-specific cerebrospinal fluid/serum Q-value calculation.

Accuracy, precision, and consistency of methods for pathogen-specific cerebrospinal fluid/serum Q-value calculation. J Immunol Methods. 2019 Oct 31;:112691 Authors: Osterman A, Böhm S, Osterman P Abstract For a CSF/serum samples pair the specific Q-value is the ratio of antibody concentrations and proportional to the pathogen-specific antibody index. It is usually extracted from optical density (OD) measurements by applying appropriate evaluation methods. Six different methods for Q-value determination, partly using parameter variation, were assessed with respect to accuracy, precision, and the methods parameter consistency. The methods are based on the Four Parameters Logistic (4PL) equation or the α-method; one method is a polygonal line composed of calibration data. We tested on OD data of 51 CSF/serum sample pairs, measured with EUROIMMUN AG (Lübeck, Germany) ELISA tests for antibody determination in CSF, as part of INSTAND e.V. proficiency survey tests for the MRZH reaction (Measles, Rubella, Varicella zoster, Herpes simplex virus). Each method was tested with four ODs, standard curve methods additionally with only two ODs, identified by a selection rule. We found all methods to be of comparable accuracy and precision. With the standard curve methods, there were no differences between two ODs and four ODs evaluations. Consistency between method parameters and measured OD values is a key property of standard curve methods with...
Source: Journal of Immunological Methods - Category: Allergy & Immunology Authors: Tags: J Immunol Methods Source Type: research