T-Cell immune activation in children with vertically transmitted hepatitis C virus infection.
Little is known concerning the clinical features, the histological outcome, and the effects on the maturation of immune system of children with vertically-transmitted hepatitis C virus (HCV) infection. Specifically, no data are available on the peripheral distribution of T-cell subsets. The frequency of naive and memory cells, activated T cells, and cytokine-producing T cells was analyzed in nine HCV-infected children born to HCV-positive mothers. In HCV-infected children, the distribution of naive and memory cells was not significantly altered in the CD4 subset whereas within the CD8 subset, an increase of memory and a decrease of naive cells was observed. The frequency of HLA-DR-positive and Fas-positive T cells was increased in HCV-infected children in both CD4 and CD8 subsets. The distribution of Fas-expressing T cells was directly related to that of HLA-DR cells and inversely related to the frequency of naive T cells. In regard with cytokine production we found increased levels of both CD4 and CD8 interferon-gamma (IFN-gamma)-producing cells whereas no difference in the percentage of interleukin-2 (IL-2)-producing T cells was observed. No meaningful correlation was observed between individual T cell subsets and ALT levels or HCV viral load. In conclusion, our results indicate an increased T-cell activation and a shift to a T(H)1 pattern of cytokine production in children with vertically transmitted HCV infection. The cause of this kind of immune response could reside in the persistent antigenic stimulation by chronic HCV infection.
Giovannetti
A
A
Department of Allergy and Clinical Immunology, University of Rome La Sapienza, Italy.
Mazzetta
F
F
Coviello
R
R
Casadei
A M
AM
Sartorerri
M R
MR
Marziali
M
M
Pierdominici
M
M
Kuonen
D
D
Pesce
A M
AM
Fiorilli
M
M
Aiuti
F
F
Quinti
I
I
D000293:Adolescent; D000367:Age Factors; D000410:Alanine Transaminase / Q000097:blood; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D016207:Cytokines / Q000096:biosynthesis; D005260:Female; D006684:HLA-DR Antigens / Q000032:analysis; D006526:Hepatitis C / Q000276:immunology* / Q000635:transmission; D006801:Humans; D018445:Infectious Disease Transmission, Vertical; D008213:Lymphocyte Activation; D008297:Male; D013601:T-Lymphocytes / Q000276:immunology*; D019014:fas Receptor / Q000032:analysis
D016207:Cytokines; D006684:HLA-DR Antigens; D019014:fas Receptor; D000410:Alanine Transaminase