Apheresis in three dogs weighing <14 kg

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.

Evaluation of the Safety and Feasibility of Apheresis in Dogs: For Application in Metastatic Cancer Research

In patients with solid tumors, circulating tumor cells (CTCs) spread in their blood and function as a seed for metastases. However, the study of CTCs has been limited by their rarity, low frequency, and heterogeneity. The efficient collection of CTCs will contribute to further research of metastatic cancers. Apheresis is a process in which the whole blood of an individual is passed through a machine that isolates a particular constituent and returns the remainder to the circulation. In the present study, we investigated the safety and feasibility of apheresis to separate peripheral blood monocytes (PBMCs), whose density is closely similar to that of CTCs, and to capture intravenously administered human breast cancer cells, MCF7s, from the dogs. No life-threatening events were observed in dogs during the apheresis process. The changes in the hemogram were transient and recovered gradually within a few days after apheresis. During apheresis, 50 mL of PBMCs could be collected from each dog. Notably, a thrombus was formed along the circuit wall during apheresis, which decreased the blood collection pressure. MCF7 cells were successfully captured by the apheresis machine. The captured cells were regrown in vitro and characterized compared with the original cells. In conclusion, apheresis could be safely performed in dogs to isolate CTCs with precautions to maintain hemodynamic stability.

Association of Veterinary Hematology and Transfusion Medicine (AVHTM) Transfusion Reaction Small Animal Consensus Statement (TRACS) Part 2: Prevention and monitoring

OBJECTIVE

To systematically review available evidence to develop guidelines for the prevention of transfusion reactions and monitoring of transfusion administration in dogs and cats.

DESIGN

Evidence evaluation of the literature (identified through Medline searches through Pubmed and Google Scholar searches) was carried out for identified transfusion reaction types in dogs and cats. Evidence was evaluated using PICO (Population, Intervention, Comparison, Outcome) questions generated for each reaction type. Evidence was categorized by level of evidence (LOE) and quality (Good, Fair, or Poor). Guidelines for prevention and monitoring were generated based on the synthesis of the evidence. Consensus on the final recommendations and a proposed transfusion administration monitoring form was achieved through Delphi-style surveys. Draft recommendations and the monitoring form were made available through veterinary specialty listservs and comments were incorporated.

RESULTS

Twenty-nine guidelines and a transfusion administration monitoring form were formulated from the evidence review with a high degree of consensus CONCLUSIONS: This systematic evidence evaluation process yielded recommended prevention and monitoring guidelines and a proposed transfusion administration form. However, significant knowledge gaps were identified, demonstrating the need for additional research in veterinary transfusion medicine.

Extracorporeal Therapies in the Emergency Room and Intensive Care Unit

Extracorporeal treatments create opportunity for removing disease causing solutes within blood. Intoxications, renal failure, and immune-mediated diseases may be managed with these treatments, often providing new hope for patients with severe or refractory disease. Understanding solute pharmacokinetics and the limitations of each type of extracorporeal technique can allow for the selection of the optimal treatment modality.

Platelet-Derived Products in Veterinary Medicine: A New Trend or an Effective Therapy?

Platelet-derived products (PDPs) have gained popularity, mainly due to their high concentrations of bioactive molecules such as growth factors and cytokines, which play important roles in tissue healing and regeneration. PDPs are obtained through minimally invasive procedures and their therapeutic effect has been widely recognized. In veterinary medicine, however, the lack of standard protocols to generate PDPs is a major hurdle for assessing the clinical relevance of PDP-based therapies and for their widespread usage. The aim of this review is to analyze the technical and scientific specificities of PDPs in terms of preparation methodologies, classification categorization, nomenclature, and biological proprieties to advance their future biotechnological potential in veterinary contexts.

Autologous cancer cell vaccination, adoptive T-cell transfer, and interleukin-2 administration results in long-term survival for companion dogs with osteosarcoma

Background

Osteosarcoma (OSA) in dogs is an aggressive bone tumor with frequent chemotherapy failure and translational relevance for human health.

Hypothesis/Objectives

We hypothesized that dogs with OSA could be treated safely by ex vivo activated T‐cells that were generated by autologous cancer vaccination and supported by interleukin‐2 (IL‐2) treatment with survival more than twice that reported for amputation alone.

Animals

Osteosarcoma‐bearing dogs (n = 14) were enrolled in a single‐arm prospective trial after complete staging before amputation. Four healthy dogs also were treated in a safety study.

Methods

Autologous cancer cell vaccinations were administered intradermally and dogs underwent leukapheresis. Mononuclear cell products were stimulated ex vivo with a T‐cell‐activating agent. Activated product was transfused and 5 SC IL‐2 injections were administered q48h. Dogs were monitored for metastasis by thoracic radiography every 3 months.

Results

Autologous cancer cell vaccine and activated cellular therapy (ACT) products were successfully generated. Toxicity was minimal after premedicants were instituted before ACT. With premedication, all toxicities were grade I/II. Median disease‐free interval for all dogs was 213 days. One dog developed cutaneous metastasis but then experienced spontaneous complete remission. Median survival time for all dogs was 415 days. Five dogs survived >730 days.

Conclusions and Clinical Importance

This immunotherapy protocol without cytotoxic chemotherapy is safe and tolerable. Compared to historical amputation reports, survival was notably prolonged in this group of patients. Additional prospective studies are warranted to elucidate active immunologic mechanisms and further improve disease response and survival.

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.

Treatment of carprofen overdose with therapeutic plasma exchange in a dog

OBJECTIVE

To report the use of therapeutic plasma exchange (TPE) in a dog with carprofen toxicosis.

SUMMARY

A 6-year-old female neutered Bichon Frise weighing 6.9 kg was examined after it had ingested 72 mg/kg carprofen. Mild dehydration without azotemia and with a urine specific gravity of 1.050 was noted at presentation. Treatment consisted of induction of emesis, symptomatic medical therapy, and TPE. The TPE achieved 1.5 plasma volume exchanges over 3 hours. Blood samples and effluent samples were collected every 30 minutes during TPE and additional blood samples were collected 11 and 35 hours after treatment. Carprofen concentrations in these samples were determined by high-pressure liquid chromatography. A 51% reduction in serum carprofen concentration was achieved following TPE.

NEW OR UNIQUE INFORMATION PROVIDED

This report describes the successful reduction of plasma carprofen concentration in a dog using TPE. Although recent studies suggest that this particular dog may not have received a toxic dose, a 51% reduction of plasma carprofen concentration was achieved over 180 minutes, and TPE may be beneficial for treatment of dogs that have ingested higher doses.

Regional Citrate Anticoagulation for Intermittent Hemodialysis in Dogs

Background

The traditional systemic heparinization used for anticoagulation in extracorporeal therapies may cause fatal complications in animals at risk of bleeding.

Hypothesis/Objectives

To develop and validate a protocol of regional citrate anticoagulation (RCA) for intermittent hemodialysis in dogs.

Animals

A total of 172 dogs treated with hemodialysis for acute kidney injury.

Methods

In vitro titration was performed, adding trisodium citrate and calcium chloride to heparinized canine blood. A tentative protocol was used first in 66 treatments with additional heparinization and subsequently in 518 heparin‐free treatments. Safety and adequacy of RCA were assessed based on clinical and laboratory monitoring, dialyzer pressure gradient, treatment completion, and visual scoring of the extracorporeal circuit.

Results

Addition of 1 mmol/L citrate to heparinized blood decreased the ionized calcium concentration by 0.23 mmol/L (95% confidence interval [CI], 0.16–0.30) and 1 mmol/L calcium increased it by 0.62 mmol/L (95% CI, 0.45–0.79). Heparin‐free treatments were initiated with infusion of trisodium citrate (102 mmol/L) at 2.55 mmol/L blood and calcium chloride (340 mmol/L) at 0.85 mmol/L. Citrate and calcium administrations were adjusted in 27 and 34% of the treatments, respectively. Overall, anticoagulation was satisfactory in 92% of the treatments, with expected azotemia reduction in 95% (urea) and 86% (creatinine), stable dialyzer pressure gradient in 82%, and clean extracorporeal circuits in 92% of the treatments. Eighteen treatments (3.5%) were discontinued prematurely, 9 because of clotting and 9 for reasons unrelated to the RCA procedure.

Conclusions and Clinical Importance

Regional citrate anticoagulation allows safe and efficient heparin‐free hemodialysis in dogs at risk of bleeding.

Renal adenocarcinoma-associated erythrocytosis in a cat: clinicopathological features and immunohistochemical results

This report documents a case of secondary inappropriate erythrocytosis in a cat with renal cell adenocarcinoma, its stabilization through manual erythrocytapheresis, and the EPO-immunostaining on the affected kidney. An 11-year-old cat was presented with lethargy, weight loss and polyuria/polydipsia. An abdominal mass was detected upon physical examination. Clinicopathological work-up revealed marked erythrocytosis (HCT value 64.8%), renal azotemia and decreased urine specific gravity (USG). An abdominal ultrasound was performed, localizing the mass in the right kidney. Serum erythropoietin (EPO) was above the reference interval (RI), and the cytology of the mass was indicative of renal carcinoma. Manual erythrocytapheresis was performed in order to stabilize the patient before surgery, improving the cat’s clinical and clinicopathological condition. After nephrectomy, EPO and creatinine concentrations returned within the RI, while the USG markedly increased. Histopathology confirmed the diagnosis of renal adenocarcinoma. Immunohistochemistry with anti-EPO antibody revealed diffuse and strong cytoplasmatic positivity in tumor cells.

Platelet lysate obtained via plateletpheresis performed in standing and awake equine donors

BACKGROUND

Platelet preparations containing growth factors, attachment factors, and enzymes are appealing to enhance healing of injured tissues and as an alternative to xenogenic serum in cell culture media. Plateletpheresis is commonly used to collect platelets in human medicine but has not been validated in horses.

STUDY DESIGN AND METHODS

Plateletpheresis to collect platelet concentrate was performed on six female, mixed breed, chemically restrained horses using commercially available apheresis equipment. Before and immediately after plateletpheresis, we performed physical examinations and collected blood for chemistry and coagulation panels and then again at 8, 16, 24, and 48 hours after the procedure. To produce platelet lysate, the platelet concentrate underwent two freeze-thaw cycles followed by centrifugation and filtration processing. The platelet lysate was then analyzed for cellular debris, fibrinogen, and growth factors.

RESULTS

The collected platelet concentration contained a mean platelet yield of 390 × 10³ /μL. Donor platelet count decreased from a mean of 193 × 10³ /μL to 138 × 10³ /μL after plateletpheresis, but no individual was at risk for hemorrhage. Pooled platelet lysate had minimal cellular residue and contained growth factor concentrations at 6.1 ng/mL for transforming growth factor-β1, at 3.5 ng/mL for platelet-derived growth factor-BB, and at 13.8 ng/mL for vascular endothelial growth factor-A.

CONCLUSION

Plateletpheresis using commercially available apheresis equipment is a feasible option for collecting platelet concentrate from equine donors. The lysate generated from the apheresis product contains growth factors and has potential to be used as a fetal bovine serum substitute for cell culture.

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 × 10⁶ 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.