Recurrent respiratory tract infections in children - analysis of immunological examinations

Abstract

Background: Paediatric respiratory tract infections are among the most common reasons for preschool and school absences and visits to physicians. The disease mainly involves the upper respiratory tract and is associated with fever, cough, sore throat, and running nose. Children with recurrent respiratory infections (RRI), which are defined as more than six serious diseases a year, are a difficult diagnostic challenge. The aim of this study was to assess immunological deviations in laboratory tests performed in children with RRI.

Material and methods: In the retrospective study 25 children suffering from recurrent respiratory tract infection, aged 4.1 ±2.3 years, 13 boys and 12 girls, were involved. For all children chemiluminescence of granulocytes and immunophenotyping of lymphocytes from peripheral blood were examined. An immunophenotype of peripheral blood lymphocytes involved evaluation of T cell, B cells, and NK cells, examined with flow cytometry.

Results: Eleven of the studied children had decreased chemiluminescent response to stimulants, normal response was found for nine children, and five children had an increased result of the test. Five of the 25 children had decreased B cells number, and five had decreased number of T cells including decrease of CD4, as well as CD8 positive cells. Children with decreased chemiluminescence had more frequent neutropaenia than children with normal or increased chemiluminescent response, p < 0.05 (exact Fisher test).

Conclusions: Recurrent respiratory tract infection could be associated with improper neutrophils response to pathogens, and immunological examination should be performed to find the reason for the increased number of infections in a year.

Keywords: chemiluminescence; immunological disturbances; immunophenotyping; recurrent respiratory tract infection.

Fig. 1

Kinetics of neutrophil chemiluminescence measured by luminol fluorescence evaluations after stimulation with fMLP A) and PMA B). Reaction time – 120 minutes, maximal fluorescence was used to describe chemiluminescent reactivity of neutrophils

Fig. 2

Immunophenotyping of peripheral blood lymphocyte subpopulations. A) SS versus Cd45log. B) Dot-plot of CD19 versus CD2. C) Dot plot of CD5 versus CD20. D) Dot plot of CD 16/56 versus CD3. E) Dot plot CD 4 versus CD8. F) Dot plot CD4 versus HLA-DR