Effects of chemotherapy on immune responses in dogs with cancer.
Chemotherapy is assumed to be immunosuppressive; yet to the authors' knowledge, the effects of common chemotherapy protocols on adaptive immune responses in dogs with cancer have not been fully evaluated. Therefore, a study was conducted to evaluate the effects of 2 common chemotherapy protocols on T- and B-cell numbers and humoral immune responses to de novo vaccination in dogs with cancer. Twenty-one dogs with cancer (12 with lymphoma, 9 with osteosarcoma) were enrolled in a prospective study to assess effects of doxorubicin versus multi-drug chemotherapy on adaptive immunity. Numbers of circulating T and B cells were assessed by flow cytometry, and antibody responses to de novo vaccination were assessed before, during, and after chemotherapy. The T- and B-cell numbers before treatment also were compared with those of healthy, age-matched, control dogs. Prior to treatment, dogs with cancer had significantly fewer (P < .05) CD4+ T cells and CD8+ T cells than did healthy dogs. Doxorubicin treatment did not cause a significant decrease in T- or B-cell numbers, whereas treatment with combination chemotherapy caused a significant and persistent decrease in B-cell numbers. Antibody titers after vaccination were not significantly different between control and chemotherapy-treated dogs. These findings suggest that chemotherapy may have less impact on T-cell numbers and ability to mount antibody responses in dogs with cancer than was previously anticipated, though dogs with lymphoma or osteosarcoma appear to be relatively T-cell deficient before initiation of chemotherapy.
Walter
Claudia U
CU
Animal Cancer Center, Department of Clinical Sciences, Colorado State University, Fort Collins 80523, USA.
Biller
Barbara J
BJ
Lana
Susan E
SE
Bachand
Annette M
AM
Dow
Steven W
SW
D000818:Animals; D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use*; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D001402:B-Lymphocytes / Q000187:drug effects / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000187:drug effects / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000187:drug effects / Q000276:immunology; D003520:Cyclophosphamide / Q000627:therapeutic use; D004283:Dog Diseases / Q000188:drug therapy* / Q000276:immunology*; D004285:Dogs; D004317:Doxorubicin / Q000627:therapeutic use; D004334:Drug Administration Schedule; D018655:Lymphocyte Count / Q000662:veterinary*; D009369:Neoplasms / Q000188:drug therapy / Q000276:immunology / Q000662:veterinary*; D011241:Prednisone / Q000627:therapeutic use; D014750:Vincristine / Q000627:therapeutic use
D000970:Antineoplastic Agents; D014750:Vincristine; D004317:Doxorubicin; D003520:Cyclophosphamide; D011241:Prednisone