Growth hormone in T-lymphocyte thymic and postthymic development: a study in HIV-infected children.
OBJECTIVE
Growth hormone (GH) plays a role in thymic function, and recombinant GH may stimulate thymopoiesis in HIV-infected individuals. We performed immunologic analyses in 26 antiretroviral-treated children matched for age, pubertal status, clinical parameters, and antiretroviral exposure who did or did not show an impaired response to GH-release stimulation tests with arginine + GH-releasing hormone.


RESULTS
The following abnormalities were found in GH-deficient compared with GH-nondeficient children after >4 years of therapy: CD4 count ( P = .02) and percentage ( P = .03), CD4 as percentage of normal cells for age ( P = .003), serum interleukin-7 concentration ( P = .02), and thymic volume ( P = .01). Naive CD4 (4+62+RA+ and 4+CCR7+RA+) and CD8 (8+CCR7+RA+) lymphocytes were lower in GH-deficient children ( P = .003; P = .007; and P = .02, respectively). Postthymic pathways were also impaired in GH-deficient children. Thus, central memory (4+CCR7+RA-) CD4+ cells were reduced ( P = .006), whereas effector memory (4+CCR7-RA-) CD4+ cells ( P = .002) and late effector CD8+ lymphocytes (8+CCR7-RA+ and 8+27-28-) ( P = .009 and P = .002, respectively) were increased in these children.


CONCLUSIONS
Growth hormone plays a role in thymic and postthymic pathways, and defective GH production may be associated with incomplete immunoreconstitution. Immunomodulant agents (including GH) could be useful in patients with defective GH production.
Pediatrics and Immunology, Milano University, Milan, Italy.
Alessandra
A
Vigano
Marina
M
Saresella
Daria
D
Trabattoni
Vania
V
Giacomet
Berardo
B
di Natale
Marzia
M
Merlo
Annunziata
A
Venuto
Maria Luisa
ML
Villa
Stefano
S
Vanzulli
Pasquale
P
Ferrante
Mario
M
Clerici
D000293:Adolescent; D019380:Anti-HIV Agents / Q000008:administration & dosage*; D023241:Antiretroviral Therapy, Highly Active; D002648:Child; D005260:Female; D015658:HIV Infections / Q000097:blood / Q000188:drug therapy / Q000276:immunology*; D019382:Human Growth Hormone / Q000097:blood* / Q000172:deficiency; D006801:Humans; D018970:Insulin-Like Growth Factor Binding Protein 1 / Q000097:blood*; D015851:Interleukin-7 / Q000097:blood; D018655:Lymphocyte Count; D008297:Male; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology*; D013950:Thymus Gland / Q000187:drug effects / Q000276:immunology*
D019380:Anti-HIV Agents; D018970:Insulin-Like Growth Factor Binding Protein 1; D015851:Interleukin-7; D019382:Human Growth Hormone