Monitoring plasma nucleosome concentrations to measure disease response and progression in dogs with hematopoietic malignancies.

BACKGROUND: Hematopoietic malignancies are extremely common in pet dogs and represent nearly 30% of the malignancies diagnosed in this population each year. Clinicians commonly use existing tools such as physical exam findings, radiographs, ultrasound and baseline blood work to monitor these patients for treatment response and remission. Circulating biomarkers, such as prostate specific antigen or carcinoembryonic antigen, can be useful tools for monitoring treatment response and remission status in human cancer patients. To date, there has a been a lack of useful circulating biomarkers available to veterinary oncology patients. METHODS: Circulating plasma nucleosome concentrations were evaluated at diagnosis, throughout treatment and during remission monitoring for 40 dogs with lymphoma, acute myelogenous leukemia and multiple myeloma. Additionally, C-reactive protein and thymidine kinase-1 levels were recorded. RESULTS: Plasma nucleosome concentrations were significantly higher at diagnosis and progressive disease than they were when dogs were in remission. All but two dogs had plasma nucleosome concentrations that returned to the low range during treatment. These two dogs had the shortest progression free and overall survival times. Dogs with the highest plasma nucleosome concentrations had a significantly shorter first progression free survival than dogs with lower plasma nucleosome concentrations at diagnosis. Plasma nucleosome concentrations correlated better with disease response and progression than either thymidine kinase or C reactive protein. CONCLUSIONS: Plasma nucleosome concentrations can be a useful tool for treatment monitoring and disease progression in dogs with hematopoietic malignancies.

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.

Plasma Cytokeratin 18 and fecal Alpha-1 Antitrypsin concentrations in dogs with osteosarcoma receiving carboplatin chemotherapy.

Gastrointestinal (GI) toxicosis is a common side effect of cytotoxic chemotherapy treatment in humans and dogs. Measurement of cytokeratin 18 (CK18), an intracellular structural protein released during epithelial apoptosis, and Alpha1-Antitrypsin (A1AT) in faeces provides a mechanism for evaluating damage to the intestinal mucosa secondary to cytotoxic chemotherapy. Our goal was to evaluate the clinical utility of plasma CK18 and faecal A1-AT levels as non-invasive biomarkers of cytotoxic chemotherapy induced GI toxicity. We conducted a prospective cohort study in dogs (N = 10) with osteosarcoma undergoing amputation followed by carboplatin chemotherapy. We hypothesized that plasma CK18 and faecal A1-AT levels would increase following carboplatin administration due to drug-induced GI epithelial damage/apoptosis, and that plasma CK18 and faecal A1-AT levels would correlate with severity of GI toxicity. Mean baseline plasma CK18 concentration was variable amongst patients; however, CK18 concentration prior to carboplatin chemotherapy treatment was not significantly different from CK18 levels after treatment. There was significant intra and inter-patient variability in mean faecal A1-AT levels at baseline. Mean A1-AT concentration did not change significantly from day 0 to day 21. Gastrointestinal toxicity was minimal; therefore, we were unable to determine the association of plasma CK18 and faecal A1-AT concentrations with development of GI toxicosis. In this study population, plasma CK18 and faecal A1-AT concentration were not clinically useful biomarkers for the detection of GI toxicosis secondary to carboplatin administration. Further prospective evaluation of CK18 and A1-AT as biomarkers of drug-induced GI toxicity is warranted in a larger cohort of dogs receiving cytotoxic chemotherapy. AVMA clinical trial registration number: AAHSD004827.

Differentiation of lymphocytic-plasmacytic enteropathy and small cell lymphoma in cats using histology-guided mass spectrometry.

BACKGROUND: Differentiation of lymphocytic-plasmacytic enteropathy (LPE) from small cell lymphoma (SCL) in cats can be challenging. HYPOTHESIS/OBJECTIVE: Histology-guided mass spectrometry (HGMS) is a suitable method for the differentiation of LPE from SCL in cats. ANIMALS: Forty-one cats with LPE and 52 cats with SCL. METHODS: This is a retrospective clinicopathologic study. Duodenal tissue samples of 17 cats with LPE and 22 cats with SCL were subjected to HGMS, and the acquired data were used to develop a linear discriminate analysis (LDA) machine learning algorithm. The algorithm was subsequently validated using a separate set of 24 cats with LPE and 30 cats with SCL. Cases were classified as LPE or SCL based on a consensus by an expert panel consisting of 5-7 board-certified veterinary specialists. Histopathology, immunohistochemistry, and clonality testing were available for all cats. The panel consensus classification served as a reference for the calculation of test performance parameters. RESULTS: Relative sensitivity, specificity, and accuracy of HGMS were 86.7% (95% confidence interval [CI]: 74.5%-98.8%), 91.7% (95% CI: 80.6%-100%), and 88.9% (95% CI: 80.5%-97.3%), respectively. Comparatively, the clonality testing had a sensitivity, specificity, and accuracy of 85.7% (95% CI: 72.8%-98.7%), 33.3% (95% CI: 14.5%-52.2%), and 61.5% (95% CI: 48.3%-74.8%) relative to the panel decision. CONCLUSIONS AND CLINICAL IMPORTANCE: Histology-guided mass spectrometry was a reliable technique for the differentiation of LPE from SCL in duodenal formalin-fixed paraffin-embedded samples of cats and might have advantages over tests currently considered state of the art.

Plasma cytokeratin-18 concentrations as noninvasive biomarker of early gastrointestinal toxicosis in dogs receiving toceranib.

BACKGROUND: No biomarkers for the early detection of gastrointestinal (GI) toxicosis secondary to antineoplastic treatment are recognized in veterinary medicine. Toceranib causes GI toxicosis in dogs. HYPOTHESIS/OBJECTIVE: To assess if changes in plasma cytokeratin 18 (CK18) concentration, measured in dogs being treated with toceranib phosphate, can predict the onset of GI toxicosis. We hypothesize that an increase in CK18 concentrations will be detected before the development of GI toxicosis in dogs treated with toceranib phosphate. ANIMALS: Twenty healthy client-owned dogs and 25 client-owned dogs with surgically excised mast cell tumor (MCT). METHODS: Prospective cohort study. Dogs were treated with toceranib (2.75 mg/kg PO q48h). Plasma was collected weekly for 4 weeks. Plasma CK18 concentration was measured on days 0, 7, 14, 21, and 28. vascular endothelial growth factor was measured on days 0 and 28. RESULTS: Mean plasma CK18 concentration on day 0 in dogs with MCT was not significantly different than healthy controls (313.5 ± 592.8 pg/mL, 119.7 ± 76.9 pg/mL, mean ± SD P = 0.27). Mean plasma CK18 concentration decreased by 98.69 pg/mL from day 0 to day 28 (P < 0.001). Plasma CK18 concentration was not a significant predictor of the development of signs of GI toxicosis. CONCLUSIONS AND CLINICAL IMPORTANCE: Plasma CK18 concentration was not a clinically useful biomarker for the early detection of GI toxicosis secondary to toceranib administration in dogs with MCTs.

Canine urinary bladder transitional cell carcinoma tumor volume is dependent on imaging modality and measurement technique.

Transitional cell carcinoma is the most common cancer of the canine urinary tract. The inconsistent appearance of transitional cell carcinoma in patients introduces error if applying mathematic models for extrapolating total tumor volume from linear measurements. Reliable techniques to assess tumor size are important for monitoring treatment response. A method comparison study was performed comparing four techniques for calculating tumor volume were compared: (1 and 2) contoured tracing of tumor margins using serial computed tomography (CT) images using pre-(1) and postintravenous (2) contrast medium studies, (3) longest three linear dimensions using CT, and (4) longest three linear dimensions on abdominal ultrasound. Volumes of the transitional cell carcinoma tumor calculated by CT tracing techniques were significantly smaller than volumes calculated with an ellipsoid mathematic model using the linear measurements (P < 0.01). Intravenous contrast medium did not significantly change the volumes calculated from tracing tumor margins on CT for observer B; however, volumes differed for observer A. The volumes extrapolated from linear measurements using CT and ultrasound did not differ significantly. The interobserver reliability was highest for the precontrast CT contoured technique and was lowest using the ultrasound linear technique. Tumor volumes differed significantly between techniques of contoured tracing of the tumor margins on serial CT images compared to calculation of tumor volume from linear dimensions. The calculated volume of a transitional cell carcinoma depends upon the technique used. Characterizing the response of urinary bladder transitional cell carcinoma tumor size to therapy differs based on the method and modality used.

Comparison of platelet function and viscoelastic test results between healthy dogs and dogs with naturally occurring chronic kidney disease.

OBJECTIVE To compare platelet function and viscoelastic test results between healthy dogs and dogs with chronic kidney disease (CKD) to assess whether dogs with CKD have platelet dysfunction and altered blood coagulation. ANIMALS 10 healthy control dogs and 11 dogs with naturally occurring CKD. PROCEDURES Blood and urine were collected once from each dog for a CBC, serum biochemical analysis, urinalysis, and determination of the urine protein-to-creatinine ratio, prothrombin time, activated partial thromboplastin time, plasma fibrinogen concentration, and antithrombin activity. Closure time was determined by use of a platelet function analyzer and a collagen-ADP platelet agonist. Thromboelastography (TEG) variables (reaction time, clotting time, α angle, maximum amplitude, and global clot strength [G value]) were determined by use of recalcified nonactivated TEG. Platelet expression of glycoprotein Ib (GPIb; receptor for von Willebrand factor), integrin αIIbß3 (αIIbß3; receptor for fibrinogen), and P-selectin (marker for platelet activation) was assessed by flow cytometry. RESULTS Compared with healthy control dogs, the median closure time was prolonged, the median maximum amplitude and G value were increased, and the median clotting time was decreased for dogs with CKD. Platelet expression of both αIIbß3 and P-selectin was also significantly increased for dogs with CKD, compared with that for control dogs. Platelet expression of GPIb, αIIbß3, and P-selectin was not correlated with closure time or any TEG variable. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that dogs with CKD frequently had evidence of platelet dysfunction and hypercoagulability that were not totally attributable to alterations in platelet surface expression of GPIb, αIIbß3, and P-selectin.

SPINAL MAST CELL TUMORS IN DOGS: IMAGING FEATURES AND CLINICAL OUTCOME OF FOUR CASES.

Published information regarding canine vertebral column mast cell tumors (MCTs) is limited. The objectives of this study were to report clinical and advanced imaging findings for a group of dogs with confirmed spinal MCT. Inclusion criteria for this retrospective case series were dogs with spinal magnetic resonance imaging (MRI) or computed tomography (CT) scans and a histological diagnosis of spinal MCT. Clinical, imaging, treatment, and outcome data were recorded. Four dogs met inclusion criteria. One dog had primary spinal MCT and three dogs had metastatic spinal MCT. All four dogs presented for paraspinal hyperesthesia and subacute progressive or acute myelopathy. All CT and MRI lesions were extradural. Two cases exhibited distinct masses in the epidural space. In one case, an epidural tumor invaded from the paravertebral musculature. One case exhibited polyostotic lesions indistinguishable from multiple myeloma by MRI. One dog with a primary epidural low-grade MCT remains clinically normal 4 years postoperatively, following adjunctive lomustine. An epidural high-grade MCT, metastatic from a cutaneous tumor, recurred within 2 months of surgery despite adjunctive vinblastine. Two high-grade cases with concurrent visceral involvement were euthanized immediately after imaging. In dogs, MCT should be considered as a differential diagnosis for a progressive painful myelopathy and CT or MRI evidence of an extradural spinal lesion (epidural, paravertebral, or polyostotic). While more often associated with cutaneous or disseminated disease, MCT may also occur as a primary tumor of the epidural space in dogs.

A pilot study of toceranib/vinblastine therapy for canine transitional cell carcinoma.

BACKGROUND: Effective therapies for transitional cell carcinoma (TCC) are limited, with objective response rates to most chemotherapeutic regimens below 20%. The purpose of this study was to investigate the biologic activity of combined toceranib phosphate and vinblastine chemotherapy for treatment of TCC. A secondary objective was to compare the utility of Computed Tomography (CT) and abdominal ultrasound (AUS) in tumor response assessments. RESULTS: Dogs with TCC received vinblastine at 1.6 mg/m2 every 2 weeks and toceranib at 2.5-2.75 mg/kg on Monday/Wednesday/Friday. Tumor monitoring was achieved through CT and AUS. Five patients completed the 16-week study. Based on AUS assessments, 3 dogs experienced biologic response to therapy including partial responses (PR, n = 2) and stable disease (SD, n = 1). Based on CT, 5 dogs experienced a biologic response (n = 2 PR, n = 3 SD). Both imaging modalities (ultrasound and CT) were found to provide repeatable measurements between operators, however agreement between operator measurements was greater when CT images were used to assess tumor size. CONCLUSIONS: The combination of toceranib and vinblastine did not result in improved response rates. While agreement in tumor volume assessments between both AUS and CT were excellent between operators, this did not extend to assessment of tumor response. The higher rate of concordance between operators when assessing response to treatment with CT suggests that CT should be considered for future clinical trials involving canine bladder TCC to improve the accuracy and repeatability of tumor measurement. The data suggest that response to therapy as assessed by AUS or CT do not predict duration of clinical response.

Disease distribution in canine patients with acanthocytosis: 123 cases.

BACKGROUND: An acanthocyte is an abnormally shaped erythrocyte. In veterinary medicine, acanthocytes have historically been associated with canine hemangiosarcoma. In human medicine, acanthocytes are rarely observed with neoplastic disease and are more commonly associated with a variety of hereditary and acquired diseases. OBJECTIVES: The purpose of the study was to determine what disease processes are associated with the presence of acanthocytes in the peripheral blood of dogs. METHODS: Medical records for dogs presented to the Veterinary Teaching Hospital of Colorado State University during January 2004 through June 2008 with acanthocytes documented in their CBCs were retrospectively reviewed. RESULTS: A total of 123 dogs were included, 66 of which were diagnosed with neoplastic disease, most commonly hemangiosarcoma (n = 12), osteosarcoma (n = 11), and lymphoma (n = 11). The remaining 57 dogs had nonneoplastic disease, most commonly observed were gastrointestinal (n = 13), musculoskeletal (n = 8), renal (n = 8), and immune-mediated diseases (n = 7). No statistically significant difference was detected between percent acanthocytes present in dogs with neoplastic and nonneoplastic diseases. CONCLUSION: Acanthocytosis was observed with a variety of neoplastic and nonneoplastic diseases. While clearly commonly associated, the presence of acanthocytes in a blood smear should not be considered pathognomonic for hemangiosarcoma in dogs.