Clinical characteristics and outcome in dogs with small cell T-cell intestinal lymphoma.

Small cell intestinal lymphoma has not been well characterized in dogs. The objective of this study was to describe clinical characteristics and outcome in dogs with small cell intestinal lymphoma. We hypothesized that affected dogs would have prolonged survival compared with high-grade gastrointestinal (GI) lymphoma. Pathology records were searched for dogs with histologically confirmed small cell GI lymphoma. Seventeen dogs with confirmed small cell intestinal lymphoma were identified, and clinical and outcome data were retrospectively collected. Histopathology was reviewed by a board-certified pathologist, and tissue sections were subjected to immunophenotyping and molecular clonality assessment. All dogs had small cell, T-cell, lymphoma confirmed within various regions of small intestine, with 1 dog also having disease in abdominal lymph nodes. All dogs had clinical signs attributable to GI disease; diarrhoea (n = 13) was most common. Ultrasonographic abnormalities were present in 8 of 13 dogs with abnormal wall layering (n = 7) and hyperechoic mucosal striations (n = 7) representing the most common findings. In total, 14 dogs received some form of treatment. The median survival time (MST) for all dogs was 279 days and the MST for the 14 dogs that received any treatment was 628 days. Dogs with anaemia and weight loss at presentation had significantly shorter survival times and dogs that received a combination of steroids and an alkylating agent had significantly longer survival times. Small cell, T-cell, intestinal lymphoma is a distinct disease process in dogs, and those undergoing treatment may experience prolonged survival.

Autologous peripheral blood hematopoietic cell transplantation in dogs with T-cell lymphoma.

BACKGROUND: Peripheral blood hematopoietic cell transplantation (PBHCT) is a feasible treatment option for dogs with B-cell lymphoma. OBJECTIVE: To examine apheresis and PBHCT outcomes in dogs diagnosed with T-cell lymphoma (TCL). ANIMALS: Fifteen client-owned dogs diagnosed with high-grade TCL. METHODS: After high-dose cyclophosphamide and rhG-colony-stimulating (rhG-CSF) factor treatment, peripheral blood mononuclear cells were collected using cell separators. The harvested cells then were infused after varying doses of total body irradiation (TBI). Postirradiation adverse effects were managed symptomatically and dogs were discharged upon evidence of hematopoietic engraftment. RESULTS: More than 2 × 10(6) CD34+ cells/kg were harvested from 15/15 dogs. Thirteen of 15 (87%) dogs engrafted appropriately, whereas 2 (13%) of the dogs died in the hospital. One dog developed cutaneous B-cell lymphoma 120 days post-PBHCT. The median disease-free interval and overall survival (OS) of the 13 dogs transplanted in first remission from the time of PBHCT were 184 and 240 days, respectively. Stage and substage of disease at diagnosis had no effect on OS. Two of 13 (15%) dogs were alive 741 and 772 days post-PBHCT. CONCLUSIONS AND CLINICAL IMPORTANCE: PBHCT may be considered as a treatment option for dogs with TCL.

Autologous peripheral blood hematopoietic cell transplantation in dogs with B-cell lymphoma.

BACKGROUND: Peripheral blood CD34+ hematopoietic cell transplantation (PBHCT) is commonly used to treat human patients with relapsed non-Hodgkin diffuse, large B-cell lymphoma with cure rates approaching 50%. OBJECTIVE: To determine the safety and feasibility of performing PBHCT to treat canine B-cell lymphoma (LSA) patients in a clinical academic setting. ANIMALS: Twenty-four client-owned dogs diagnosed with B-cell LSA. METHODS: After high-dose cyclophosphamide and rhG-colony-stimulating factor treatment, peripheral blood mononuclear cells were collected using cell separator machines. The harvested cells then were infused after a 10 Gy dose of total body irradiation (TBI). Post-irradiation adverse effects were managed symptomatically and dogs were discharged upon evidence of engraftment. RESULTS: More than 2 × 10(6) CD34+ cells/kg were harvested in 23/24 dogs. Preapheresis peripheral blood monocyte count was correlated with the number of CD34+ cells/kg harvested. Twenty-one of 24 (87.5%) dogs engrafted appropriately, whereas 2 dogs (8.3%) died in the hospital. One (5%) dog exhibited delayed engraftment and died 45 days after PBHCT. One dog developed presumed TBI-induced pulmonary fibrosis approximately 8 months after PBHCT. The median disease-free interval and overall survival (OS) of all dogs from the time of PBHCT was 271 and 463 days, respectively. Five of 15 (33%) dogs transplanted before they relapsed remain in clinical remission for their disease at a median OS of 524 days (range, 361-665 days). CONCLUSIONS AND CLINICAL IMPORTANCE: In most cases, PBHCT led to complete hematologic reconstitution. Therefore, PBHCT may be considered as a treatment option for dogs with B-cell lymphoma.