Post-natal ontogenesis of the T-cell receptor CD4 and CD8 Vbeta repertoire and immune function in children with DiGeorge syndrome.
DiGeorge syndrome (DGS) is a congenital disorder characterized by typical facial features, hypoparatyroidism, conotruncal cardiac defects and thymic hypoplasia. Although there are some reports addressing lymphocytes counts and function in DGS children over time, few data have been reported on the T-cell receptor V beta (TCRBV) repertoire in relation to disease progression. The aim of this study was to evaluate the degree and nature of immunodeficiency and to investigate a possible correlation to clinical findings. We used third complementary region (CDR3) size spectratyping as a tool for monitoring T-cell repertoire diversity in 7 DGS's children. The rate of thymic output, the phenotype and function of peripheral T-cells and the humoral immunity were also investigated. At baseline a profound alteration of the TCR repertoire was noted, mainly in the CD8+ T-cells, in DGS patients when compared to a control group. Furthermore, analysis of thymic output showed a significant decrease in TCR rearrangement excision circles (TRECs) levels in the patient group. Immunoglobulin abnormalities were also detected. The observed TCR repertoire alterations, although not statistically significant, may suggest an increased susceptibility to infections. A parallel increase in the TCR repertoire diversity and clinical improvement occurred during the follow-up. Our results confirm that the extent of immunodeficiency is highly variable and could improve through childhood, and indicate that TCR repertoire may be a useful marker to clinically monitor thymic function in this primary immunodeficiency.
Department of Public Health, University of Tor Vergata, Rome, Italy.
Caterina
C
Cancrini
Maria Luisa
ML
Romiti
Andrea
A
Finocchi
Silvia
S
Di Cesare
Patrizia
P
Ciaffi
Claudia
C
Capponi
Savita
S
Pahwa
Paolo
P
Rossi
D000917:Antibody Formation; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D002648:Child; D002675:Child, Preschool; D022801:Complementarity Determining Regions; D004062:DiGeorge Syndrome / Q000276:immunology*; D005260:Female; D015321:Gene Rearrangement; D005803:Genes, Immunoglobulin; D006801:Humans; D007223:Infant; D008297:Male; D010641:Phenotype; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000235:genetics*; D013950:Thymus Gland / Q000502:physiology
D022801:Complementarity Determining Regions; D016693:Receptors, Antigen, T-Cell, alpha-beta