Paediatric Reference Values for the Peripheral T cell Compartment

Abstract

Immunophenotyping of blood lymphocyte subpopulations is an important tool in the diagnosis of immunological and haematological diseases. Paediatric age‐matched reference values have been determined for the major lymphocyte populations, but reliable reference values for the more recently described T lymphocyte subpopulations, like different types of memory T lymphocytes, recent thymic emigrants, regulatory T cells and CXCR5+ helper T lymphocytes, are not sufficiently available yet. We determined reference values for the absolute and relative sizes of T lymphocyte subpopulations in healthy children using the lysed whole blood method, which is most often used in diagnostic procedures. When the absolute numbers of some or all T lymphocyte subpopulations fall outside these reference ranges, this may indicate disease. The reference values show the course of T lymphocyte development in healthy children. Absolute T lymphocyte numbers increase 1.4‐fold during the first months of life, and after 9–15 months, they decrease threefold to adult values; this is mainly caused by the expansion of recent thymic emigrants and naive cells. Helper and cytotoxic T lymphocytes show the same pattern. Regulatory T cells increase in the first 5 months of life and then gradually decrease to adult values, although the absolute numbers remain small. The relative number of CXCR5+ cells within the CD4+CD45RO+ T lymphocytes increases during the first 6 months of life and then remains more or less stable around 20%.

Impact of thymoglobulin prior to pediatric unrelated umbilical cord blood transplantation on immune reconstitution and clinical outcome

“…34 Potentially, various patient/donor-dependent variables such as weight, lymphocyte count prior to UCBT, and age influence ATG PK and pharmacodynamics (PD). 35 Further improving outcome after UCBT may therefore require a more individualized approach to ATG timing and dose adapted to indication, immunologic status, and infectious comorbidities of the patient. This can possibly be achieved by implementing PK/PD modeling techniques for antibody agents such as ATG.…”

Age‐ and sex‐related reference intervals of lymphocyte subsets in healthy ethnic Han Chinese children

“…Lymphocyte subset distributions by age are reported in Table 1 (percentages) and Table 2 (absolute counts 310 9 /L), which also list WBC and lymphocyte values. We tabulated the 10th and 90th percentiles, in addition to 11 (6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18) 11 (6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20) 11 (7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22) …”

“…Changes in antibody production are the hallmark of various human B-cell deficiencies, known as primary antibody deficiencies (PADs); these conditions are the most common primary immunodeficiencies (PIDs) (5). Some studies (1,2,(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19) have demonstrated that age, sex, race, geographic area, and nutritional status can influence variation in Department of Clinical Laboratory, The Third Affiliated Hospital of Zhengzhou University, Zhengzhou, China lymphocyte subsets, and undernutrition due to insufficient intake of energy and macronutrients and/or due to deficiencies in specific micronutrients can impair the immune system, such as suppressing immune functions that are fundamental to host protection (20), which could in turn influence the distribution of different lymphocyte subsets. Normally, the immune system is functionally immature at birth, and it undergoes sequential development that is genetically determined and additionally stimulated by antigen exposure (21).…”

Lymphocyte Subsets and Cytokines in Blood and Cerebrospinal Fluid in Children With Viral and Bacterial Meningitis

“…По данным литературы, у здоровых детей в возрастном интервале от 1 года до 16 лет со-отношение основных субпопуляций среди Т-лимфоцитов крови изменяется незначи-тельно и практически соответствует показате-лям у взрослых здоровых доноров [11,25]. Эти сведения дают возможность сопоставить от-носительное содержание субпопуляций лим-фоцитов у детей в возрасте от 1 года до 16 лет, переносящих вирусные или бактериальные менингиты (табл.…”