Thymic function in adults: evidence derived from immune recovery patterns following myeloablative chemotherapy and stem cell infusion.
We studied 45 patients aged 14-66 years who had undergone stem cell transplantation for a variety of malignant conditions at least 12 months previously. Compared to normal controls, they had significantly reduced absolute numbers of CD4+, CD4+ CD45RA+ and CD4+ CD45RO+ T cells and a reduced CD4+ CD45RA+:CD4+ CD45RO+ ratio. In all subsets T-cell numbers were significantly greater 24 months, compared to 12-24 months, after transplantation and there was a nonsignificant trend towards lower T-cell numbers with increasing age. We conclude that the thymus, or putative thymic-equivalent tissue, remains functional in older adults.
Cavenagh
J D
JD
Department of Haematology, The Royal London Hospital, Whitechapel, London.
Milne
T M
TM
Macey
M G
MG
Newland
A C
AC
D000293:Adolescent; D000328:Adult; D000368:Aged; D015703:Antigens, CD / Q000276:immunology; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D019337:Hematologic Neoplasms / Q000503:physiopathology / Q000628:therapy*; D018380:Hematopoietic Stem Cell Transplantation; D006801:Humans; D008206:Lymphatic Diseases / Q000503:physiopathology; D018655:Lymphocyte Count; D008231:Lymphopenia / Q000276:immunology; D008875:Middle Aged; D013601:T-Lymphocytes / Q000276:immunology; D013950:Thymus Gland / Q000503:physiopathology*; D019172:Transplantation Conditioning; D014181:Transplantation Immunology
D015703:Antigens, CD; D000970:Antineoplastic Agents