The Establishment Of Reference Intervals Of Lymphocyte Subsets And Clinical Application In Henan Healthy Children Younger Than 7 Years Of Age

Lymphocyte subsets was an important component in human immune function,especially in antiinfection immune of children, is the most effective weapon defense pathogen invasion. Lymphocyte subsets include total T-cells(CD3+), Th(T helper, CD3+CD4+) and Tc(cytotoxic T cells, CD3+CD8+), B-cells(CD3-CD19+) and NK-cells(CD3-CD16+CD56+), according to biological function and surface antigen of lymphocyte. Lymphocyte subsets analysis is to determine the cellular immunity and humoral immunity levels as important indicators, it can reflect the body’s immune status, function and balance.Reference intervals is also called reference ranges, is the main basis for clinicians make accurate judgment based on inspection results of patients or healthy check-up. There are few researchs about lymphocyte subsets of healthy children in China, and literatures have demonstrated that not only age but also ecological environment and social economy can influence lymphocyte subsets variation. Data on the reference intervals of lymphocyte subsets for healthy children in China have been scarce, especially for children younger than 7 years old. Reference intervals of lymphocyte subsets for American adults, provided by reagent manufacturer specifications, are already being utilized for clinical decisions. Therefore, in order to improve the level of clinical laboratory in diagnosis, we should establish age- and sex- related reference intervals of lymphocyte subset for Chinese children.ObjectiveThis study regarded healthy Han children younger than 7 years as the research objects, according to the WS/T402-2012 “clinical laboratory testing project reference range” specification requirements, to determine the age- and sex-related reference intervals of lymphocyte subsets of children younger than 7 years old in Henan.Applying the established reference interval to determine the lymphocyte subsets in respiratory tract infectious disease’s, analyse the changes in the level of immunity.Methods1. The sampling of children was divided into 7 age strata: 0 to 1 years old; 1 to 2years old; 2 to 3 years old; 3 to 4 years old; 4 to 5 years old; 5 to 6 years old and 6 to7 years old. And retrospective selection younger than 3 years bronchitis(111),bronchopneumonia(418), and bronchiolitis(83) were research objects, analysis of the changes in the level of immunity.2. Describing the percentages and absolute counts of lymphocyte subsets by flow cytometry and blood cell counter.Results1. The effect of age was evaluated among age groups, T-cells, Th, Tc, CD4/CD8 ratio, B-cells and NK-cells with differed significantly(P=0.001,0.001,0.001,0.001,0.001,0.001), except for the TC cells percentages of girls and NK cells absolute counts of boys.2. The effect of sex was evaluated among few age group, with differed significantly(P < 0.05).3. The percentages of T-cells,Tc and NK-cells were increased with age, and Th,B-cells and the CD4/CD8 ratio were decreased with age, the absolute counts of lymphocyte subsets peaked during first year and then decreased steadily with age.4. Self-built children lymphocyte subsets reference intervals compared with Hong Kong, the United States, Cameroon and Italy published research, it show that the percentages and absolute counts of lymphocyte subsets distribution wereobviously different.5. Self-built reference range used in children with lower respiratory tract infectious disease, the children existed different levels of cellular immune low or disorder, and humoral immune function.ConclusionsAccording to the “clinical laboratory testing project reference range”specification requirements, age- and sex- related reference intervals of lymphocyte subsets of children has been established. Self-built reference range were suitable for local children and helpful to the diagnosis of the disease.