Pediatric Immunology Glossary
100 terms total — 24 showing — Last updated 15 Sep 2026
opsonization
The process of coating pathogens with antibodies or complement proteins to enhance phagocytosis by immune cells.
Purine Nucleoside Phosphorylase Deficiency
A rare autosomal recessive metabolic immunodeficiency caused by absent purine nucleoside phosphorylase enzyme activity,...
RAG Deficiency
An immunodeficiency caused by mutations in the recombination-activating genes RAG1 or RAG2, impairing V(D)J recombinatio...
regulatory T-cell deficiency
Reduced numbers or impaired function of immune regulatory cells, leading to autoimmunity and inflammation in children.
Reticular Dysgenesis
The most severe form of SCID, caused by mutations in the adenylate kinase 2 (AK2) gene, characterised by absent lymphocy...
SCID
Severe Combined Immunodeficiency, a group of rare genetic disorders causing profound immune system dysfunction in infant...
Selective IgA Deficiency
The most common primary antibody deficiency, defined by a serum IgA level below 0.07 g/L in individuals aged four years...
Specific Antibody Deficiency
A condition in which serum immunoglobulin levels are normal but the patient fails to mount adequate antibody responses t...
subcutaneous immunoglobulin
Immunoglobulin preparation administered via subcutaneous injection as an alternative to intravenous delivery.
superantigen
Microbial toxins that cause massive T-cell activation and cytokine release, implicated in pediatric toxic shock syndrome...
syndromic immunodeficiency
A primary immunodeficiency that occurs as part of a broader genetic syndrome affecting multiple organ systems.
T-cell enumeration
Laboratory test measuring the number and types of T-lymphocytes, crucial for diagnosing immunodeficiency disorders.
T-cell proliferation assay
A functional test measuring T-cell activation and division in response to various stimuli.
T-cell receptor excision circle
Circular DNA fragments generated during T-cell receptor gene rearrangement, used as markers of recent thymic T-cell prod...
thymic aplasia
Complete absence or severe underdevelopment of the thymus gland, resulting in severe T-cell immunodeficiency.
thymic hypoplasia
Underdevelopment or reduced size of the thymus gland, often associated with T-cell immunodeficiency.
thymic involution
Age-related shrinkage of the thymus gland that begins in childhood, affecting T-cell production and immune competence.
thymic output
The production rate of naive T-cells by the thymus, often assessed in pediatric patients to evaluate immune system devel...
thymic shadow
Radiographic appearance of the thymus gland on chest X-ray, used to assess thymic presence and size in immunodeficiency...
transient hypogammaglobulinemia of infancy
A temporary delay in immunoglobulin production that typically resolves by 18-24 months of age.
TREC
Circular DNA byproducts of T-cell receptor gene rearrangement, used as biomarkers for thymic function and T-cell product...
TRECs
T-cell receptor excision circles, circular DNA byproducts used as biomarkers of thymic output in newborn screening.
trough level
The lowest concentration of immunoglobulin in the blood, typically measured just before the next scheduled dose.
vaccine nonresponder
An individual who fails to develop protective immunity following standard vaccination, often indicating underlying immun...
vaccine response assessment
Laboratory evaluation of antibody production following vaccination to determine immune system function.