Allogeneic peripheral blood haematopoietic stem cell transplantation for the treatment of dogs with high-grade B-cell lymphoma.

Autologous peripheral blood haematopoietic stem cell transplantation (HCT) cures 33%-40% of dogs with high-grade B-cell lymphoma. We hypothesized, based on human allogeneic bone marrow transplantation literature, that transplanting dogs using canine donor leukocyte-matched CD34+ cells would lead to fewer relapses and increased cure rates. We retrospectively reviewed medical records of dogs diagnosed with high-grade B-cell lymphoma who received an identical allogeneic HCT. A total of 15 dogs transplanted at four facilities were identified. Five of fifteen dogs relapsed before transplant. The mean number of donor CD34+ cells/kg harvested and infused into recipient dogs was 8.0 × 106 /kg (range: 2.08 × 106 /kg-2.9 × 107 /kg). The median disease-free interval and overall survival of all dogs was 1095 days (range: 9-2920 days) and 1115 days (range: 9-2920 days), respectively. Two of five dogs, not in remission at transplant, died in the hospital. The median disease-free interval and overall survival of the remaining three dogs was 25 days (range: 15-250 days) and 1100 days (range: 66-1902 days), respectively. The median disease-free interval and overall survival of the 10 dogs who had not relapsed was 1235 days (range: 19-2920 days) and 1235 days (range: 19-2920 days), respectively. One dog died soon after discharge of presumed gastric-dilatation-volvulus. Eight of nine remaining dogs lived >4 yrs post-alloHCT, leading to a cure rate of 89%. Acute graft versus host disease was seen in three dogs. These results suggest that allogeneic HCT can cure ~50% more dogs than those treated with autologous HCT.

Centrifugal therapeutic plasma exchange in dogs with immune-mediated hemolytic anemia (2016-2018): 7 cases.

OBJECTIVE: To describe the technique of centrifugal therapeutic plasma exchange (cTPE) in dogs diagnosed with immune-mediated hemolytic anemia (IMHA) and summarize the outcome of the procedure. DESIGN: Retrospective review of cTPE performed at North Carolina State University from 2016 to 2018, through a search of the institutional database for cTPE and IMHA. SETTING: University teaching hospital. ANIMALS: Seven dogs with confirmed IMHA were presented to a university teaching hospital ICU for cTPE. Six dogs were not responsive to standard medical management with immunosuppressive agents, while 1 dog presented before immunosuppressive agents were begun. INTERVENTIONS: All dogs underwent multiple cTPE procedures using 1 of 2 commercially available apheresis systems. MEASUREMENTS AND MAIN RESULTS: At presentation, the median HCT was 0.15 L/L (15.7%) (range, 0.10-0.19 L/L [10.3%-19%]) and the median total serum bilirubin was 32.5 mmol/L (1.9 mg/dl) (range, 15.4-597 mmol/L [0.9-34.9 mg/dl]). The median number of transfusions before cTPE was 1 (range, 1-4), with a median total of infused RBCs of 12.9 ml/kg (range, 8.8-37 ml/kg). cTPE with an exchange of ≥4 times total plasma volumes was used to decrease the level of circulating autoreactive antibodies. The median total plasma volumes exchanged was 4.5 times (range, 2.5-6.5 times) over 2-4 procedures. Anticoagulation was performed using a combination of systemic heparinization and regional citrate in all dogs. Six of 7 dogs (85.7%) were discharged from the hospital and were alive 90 days after discharge. One dog (14%) did not respond to cTPE (∼6.5 times total plasma volume exchanged) and was euthanized. CONCLUSIONS: cTPE is a feasible and relatively safe bridging treatment option for the management of canine IMHA.

A Retrospective Analysis: Autologous Peripheral Blood Hematopoietic Stem Cell Transplant Combined With Adoptive T-Cell Therapy for the Treatment of High-Grade B-Cell Lymphoma in Ten Dogs.

In humans, a type of cellular immunotherapy, called adoptive T cell transfer (ACT), can elicit curative responses against hematological malignancies and melanoma. ACT using ex vivo expanded peripheral blood T-cells after multiagent chemotherapy enhances tumor-free survival of dogs with B-cell lymphoma (LSA). Since 2008, our group has been performing autologous peripheral blood hematopoietic stem cell transplants (autoPBHSCT) for the treatment of canine high-grade B-cell LSA, although relapse of residual disease is a common cause of reduced survival in ~70% of treated dogs. We reasoned that a more aggressive treatment protocol combining CHOP (cyclophosphamide, doxorubicin, vincristine, prednisone) chemotherapy, autoPBHSCT, and ACT to treat 10 dogs with B-cell LSA could lead to better outcomes when compared to dogs treated with CHOP chemotherapy and autoPBHSCT alone. Using this protocol, once dogs achieved complete hematologic reconstitution post-autoPBHSCT, CD3+ CD8+ and CD3+CD4+ T-cells were expanded from the peripheral blood at a commercial laboratory. Two to four ACT infusions were given to each dog, with a total of 23 infusions given. Infusions were administered with no complications or adverse events. The median cell dose for all infusions was 5.62 x 106 cells/kg (range: 2.59 x 106-8.55 x 106 cells/kg). 4/10 (40%) of dogs were cured of their disease (defined as disease-free for ≥2 years post-autoPBHSCT). Our results confirm that the autoPBHSCT protocol did not hinder the in vitro expansion of autologous peripheral blood T-cells and that the final product could be administered safely, with no adverse events recorded. Finally, since only ten dogs were treated, our results can only suggest that the administration of ACT to dogs after multiagent chemotherapy and autoPHSCT did not lead to a statistically significant increase in median disease-free interval and overall survival when compared to dogs who received CHOP chemotherapy and autoPHSCT alone.

Clinical Application of Apheresis in Very Small Dogs Weighing <8 kg to Pediatric Patients.

Apheresis in low body weight children and adolescents is challenging due to a variety of technical and clinical issues including vascular access, low total blood volume, and hypotension. Although dogs have been a valuable preclinical model for apheresis, the procedure can be challenging since many pure-bred dogs are extremely small. Therefore, apheresis in these very small breeds presents very similar challenges as seen when performing the procedure in very low body weight people. We describe apheresis of four very small dogs, weighing from 4.6 to 7.6 kg, using either a COBESpectra and Spectra Optia apheresis system (Terumo BCT, Lakewood, CO, USA). Two dogs underwent large volume leukapheresis to collect mononuclear cells in preparation for hematopoietic stem cell transplantation and two dogs underwent therapeutic plasma exchange to treat an immune-mediated disease. In all cases, a dual-lumen hemodialysis catheter placed in the jugular vein provided adequate machine inlet and return flow rates. Machine priming was necessary to maintain hemodynamic stability during the beginning of the procedure, and rinseback was avoided for the same reason. Anticoagulant citrate dextrose solution, solution A was used for the large volume leukapheresis procedures and a combination of anticoagulant citrate dextrose solution, solution A and heparin was used for the therapeutic plasma exchange procedures. As such, serum iCa levels were regularly monitored and 10% calcium gluconate constant rate infusions were used to prevent citrate toxicity. All dogs completed the aphereses with no life-threatening adverse events. We conclude that aphereses in very small dogs is feasible if close attention is paid to hemodynamic stability and citrate toxicity.

MiR-34a chemosensitizes bladder cancer cells to cisplatin treatment regardless of p53-Rb pathway status.

MiR-34a is a downstream effector of p53 that has been shown to target several molecules associated with cell cycle and cell survival pathways. As alterations in these pathways are frequent in muscle invasive transitional cell carcinoma of the bladder (MI-TCC), for example mutation or loss of p53 and Rb, the goal of this study was to determine whether manipulation of miR-34a expression levels could abrogate the effect of these alterations and sensitize bladder cancer cells to chemotherapy. We demonstrate that transfection of T24, TCCSUP and 5637 with pre-miR-34a followed by cisplatin treatment results in a dramatic reduction in clonogenic potential and induction of senescence compared to treatment with cisplatin alone. Molecular analyses identified Cdk6 and sirtuin (SIRT)-1 as being targeted by miR-34a in MI-TCC cells, however, inhibition of Cdk6 and SIRT-1 was not as effective as pre-miR-34a in mediating chemosensitization. Analysis of 27 preneoadjuvant chemotherapy patient samples revealed many of the patients who subsequently did not respond to treatment (based on surgical resection postchemotherapy and 5-year survival data) express lower levels of miR-34a, however, a statistically significant difference between the responder and nonresponder groups was not observed (p = 0.1174). Analysis of eight sets of pre- and postneoadjuvant chemotherapy patient samples determined miR-34a expression increased postchemotherapy in only two of the eight patients. The combined data indicate that elevation of miR-34a expression levels before chemotherapy would be of benefit to MI-TCC patients, particularly in a setting of low miR-34a expression.