Original Research ARTICLE
Focusing on good responders to pneumococcal polysaccharide vaccination in general hospital patients suspected for immunodeficiency. A decision tree based on the 23-valent Pneumococcal IgG assay
- 1Tranzo, Tilburg School of Social and Behavioral Sciences, Tilburg University, Netherlands
- 2Amalia Children's Hospital, Department of Pediatrics, Radboud University Nijmegen Medical Centre, Netherlands
- 3Laboratory for Medical Microbiology and Immunology, Elisabeth Tweesteden Hospital (ETZ), Netherlands
- 4Laboratory of Medical Microbiology, Jeroen Bosch Ziekenhuis, Netherlands
- 5Science Department, University College Roosevelt, Netherlands
Background & Aim: Recently, the 23-valent IgG-assay was suggested as screening assay to identify poor responders to pneumococcal polysaccharide (PnPS)-vaccination with the serotype-specific assay as a second-line test. However, in a low pre-test probability general hospital setting predicting good responders could be more valuable to reduce the number of samples needing serotyping.
Methods: Serotype-specific PnPS antibody-assays were performed for suspected immunodeficiency in two Dutch general hospitals (Jeroen Bosch Hospital, ‘s-Hertogenbosch; Elisabeth Tweesteden Hospital, Tilburg). 23-valent PnPS antibody-assays were subsequently performed in archived material. Data were analysed using receiver operating characteristic curves (AUC) and agreement indices (ICC).
Results: Sera of 284 patients (348 samples) were included; 23-valent IgG-titres and the corresponding sum of PnPS-serotype specific antibodies showed moderate correlation (ICC=0.63). In 232 conjugated-pneumococcal-vaccine-naïve patients (270 samples), a random 23-valent IgG-titre could discriminate between samples with and without 7/11, ≥7/13 or 6/9 pneumococcal serotypes when both cut-off values 0.35 and 1.0 g/ml were used (AUC 0.86 and 0.92, respectively). All patients with a pre-immunisation-titre 38.2 g/ml and/or post-immunisation-titre 96.1 g/ml and none with a post-immunisation-titre 38.5 g/ml exhibited a good response to PnPS vaccination. Using these breakpoints as screening test to predict good responders, only 24% of patients would require further serotyping, as opposed to 68% if breakpoints to predict poor responders would have been used.
Conclusion: In a low pre-test probability setting, the 23-valent IgG-assay proved to be a reliable screening test for good responders in conjugated-pneumococcal-vaccine-naïve patients, reducing the overall number of patient samples needing further serotyping, thus reducing overall costs of pneumococcal vaccination response assessment.
Keywords: Primary immunodeficiency, Humoral immunodeficiency, pneumococcal polysaccharide response, serotype-specific assay, polysaccharide response, pneumococcal vaccination response, 23-valent IgG assay, VaccZymeTM
Received: 11 Jun 2019;
Accepted: 07 Oct 2019.
Copyright: © 2019 Janssen, Heron, Murk, Leenders, Rijkers and De Vries. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Prof. Esther De Vries, Tilburg School of Social and Behavioral Sciences, Tilburg University, Tranzo, Tilburg, 5037 AB Tilburg, Netherlands, email@example.com