Prognostic value of pretreatment plasma D-dimer level in dogs with intermediate to high-grade non-Hodgkin lymphoma.

Pretreatment D-dimer levels have been reported to predict survival in several types of malignancies in human patients. The objective of this study was to evaluate the prognostic value of pretreatment D-dimer level in dogs with intermediate to high-grade non-Hodgkin lymphoma (NHL). In a prospective, randomized, double-blind study of F14512 vs etoposide phosphate, we assessed the prognostic value of pretreatment plasma D-dimer level in 48 client-owned dogs diagnosed with intermediate to high-grade NHL. The correlation between pretreatment plasma D-dimer level and various clinical features, progression-free survival (PFS) and overall survival (OS) was analysed. The median value of pretreatment plasma D-dimer level was 0.4 µg/mL (range: 0.1-14.3 µg/mL). High pretreatment plasma D-dimer level (>0.5 µg/mL) was detected in 44% (21/48) of dogs. High D-dimer levels were not correlated with naive vs relapsed lymphoma, clinical stage, substage, immunophenotype or treatment group. D-dimer levels >0.5 µg/mL were significantly associated with inferior median PFS (54 vs 104 days, P = .011) and OS (93 vs 169 days, P = .003). In the multivariate analysis, high D-dimer levels remained an independent predictor for worse PFS (HR: 3.21, 95% CI: 1.57-6.56, P = .001) and OS (HR: 3.87, 95% CI: 1.88-7.98; P < .001). This study suggests that pretreatment plasma D-dimer level can serve as a predictor of prognosis in dogs with intermediate to high-grade NHL. Further studies are warranted to confirm these findings.

Randomized, double-blind trial of F14512, a polyamine-vectorized anticancer drug, compared with etoposide phosphate, in dogs with naturally occurring lymphoma.

Purpose: F14512 is an epipodophyllotoxin derivative from etoposide, combined with a spermine moiety introduced as a cell delivery vector. The objective of this study was to compare the safety and antitumor activity of F14512 and etoposide phosphate in dogs with spontaneous non-Hodgkin lymphoma (NHL) and to investigate the potential benefit of F14512 in P-glycoprotein (Pgp) overexpressing lymphomas. Experimental Design: Forty-eight client-owned dogs with intermediate to high-grade NHL were enrolled into a randomized, double-blind trial of F14512 versus etoposide phosphate. Endpoints included safety and therapeutic efficacy. Results: Twenty-five dogs were randomized to receive F14512 and 23 dogs to receive etoposide phosphate. All adverse events (AEs) were reversible, and no treatment-related death was reported. Hematologic AEs were more severe with F14512 and gastrointestinal AEs were more frequent with etoposide phosphate. F14512 exhibited similar response rate and progression-free survival (PFS) as etoposide phosphate in the global treated population. Subgroup analysis of dogs with Pgp-overexpressing NHL showed a significant improvement in PFS in dogs treated with F14512 compared with etoposide phosphate. Conclusion: F14512 showed strong therapeutic efficacy against spontaneous NHL and exhibited a clinical benefice in Pgp-overexpressing lymphoma superior to etoposide phosphate. The results clearly justify the evaluation of F14512 in human clinical trials.

Characterization of a novel canine T-cell line established from a spontaneously occurring aggressive T-cell lymphoma with large granular cell morphology.

Dogs with lymphoma are established as good model for human non-Hodgkin lymphoma studies. Canine cell lines derived from lymphomas may be valuable tools for testing new therapeutic drugs. In this context, we established a canine T-cell line, PER-VAS, from a primary aggressive T-cell lymphoma with large granular morphology. Flow cytometric analysis revealed a stable immunophenotype: PER-VAS cells were positively labelled for CD5, CD45, MHC II and TLR3, and were negative for CD3, CD4 and CD8 expression. Although unstable along the culture process, IL-17 and MMP12 proteins were detectable as late as at passages 280 and 325i.e. respectively 24 and 29 months post isolation. At passage 325, PER-VAS cells maintained the expression of IL-17, CD3, CD56, IFNγ and TNFα mRNAs as shown by RT-PCR analysis. Stable rearrangement of the TCRγ gene has been evidenced by PCR. PER-VAS cells have a high proliferation index with a doubling time of 16.5h and were tumorigenic in Nude mice. Compared to the canine cell lines already reported, PER-VAS cells display an original expression pattern, close to NKT cells, which makes them valuable tools for in vitro comparative research on lymphomas.

Canine bone marrow cytological examination, classification and reference values: A retrospective study of 295 cases.

Cytologic assessment of bone marrow with knowledge of the hemogram represents an effective method to investigate hemic tissue and its function. To determine the spectrum and prevalence of canine bone marrow disorders over a 2 year period in a diagnostic laboratory setting achieved through a standard approach to cytologic bone marrow assessment. A retrospective study of bone marrow fine needle aspirates sample preparations, blood smears, hemogram data and case records. Of the 295 bone marrow samples evaluated, 90 (30.5%) were nondiagnostic samples. Of the remaining samples, 25.1% were classified as hyperplasia of which most were granulocytic hyperplasia (58.1% of the total hyperplasia), 19.3% had no cytological abnormalities, 12.9% had malignant hemopathy and 7.8% had hypo-aplastic conditions. Only a small proportion of cases involved dysplasia (1.7%) and metastatic disease was detected in only one case (0.3%). Reference values of nucleated cells and the M/E ratio were calculated for normal and erythroid and granulocytic hyperplastic bone marrow. This study provides the spectrum and the prevalence of canine bone marrow disorders as well as a differential bone marrow cell counting and determination of reference intervals for diseases.

Mammary gland carcinoma in a dog with peripheral blood and bone marrow involvement associated with disseminated intravascular coagulation.

A 7-year-old female Leonberger dog was referred to the National Veterinary School of Lyon Teaching Hospital with a 2-day history of anorexia and bleeding. A mammary mass had been removed 7 months earlier, but histologic examination was not performed. On physical examination, the dog was depressed and had pale mucous membranes and numerous petechiae and hematomas. Significant laboratory findings were moderate thrombocytopenia, prolonged prothrombin, activated partial thromboplastin, and thrombin times, hypofibrinogenemia, and increased concentration of fibrin(ogen) degradation products. A peripheral blood smear, buffy coat preparation, and bone marrow aspirate contained low numbers of large atypical cells that had moderate nuclear:cytoplasmic ratios, oval nuclei with multiple prominent nuclei, and basophilic cytoplasm with villous projections. A small nodule was found in the left inguinal mammary gland, and a fine-needle aspirate contained cells similar to those in blood and bone marrow. In samples of blood, bone marrow, and the mammary mass, the neoplastic cells were immunoreactive for cytokeratin. The diagnosis was mammary carcinoma with secondary disseminated intravascular coagulation (DIC) and disseminated tumor cells in bone marrow and circulating tumor cells in blood; this diagnosis was not confirmed by histopathologic examination. Owing to clinical deterioration and the poor prognosis, the dog was euthanized and a necropsy was not performed. This is the first report of a canine mammary carcinoma with circulating tumor cells and secondary DIC.

Waldenström's macroglobulinemia in a dog with a bleeding diathesis.

An 11-year-old female spayed Whippet dog was referred to the Veterinary Hospital of the National Veterinary School of Lyon with a 3-month history of chronic bleeding, cutaneous masses suggestive of hematomas, and hemorrhagic diarrhea. Laboratory abnormalities included leukopenia with neutropenia and lymphopenia, rouleaux formation, marked hyperproteinemia with hyperglobulinemia and normoalbuminemia, hypercalcemia, markedly increased serum urea concentration, mildly increased creatinine concentration, and proteinuria. Hemostatic screening tests showed marked prolongation of thrombin time, increased concentrations of fibrin(ogen) degradation products and D-dimers, and slightly prolonged activated partial thromboplastin time. Serum and urine protein electrophoresis revealed a monoclonal peak identified as IgM by immunoelectrophoresis and an M-spike, respectively. Cytologic evaluation of bone marrow revealed a hypocellular sample with lymphoplasmacytic cells comprising approximately 50% of all nucleated cells. These findings were consistent with a diagnosis of Waldenström's macroglobulinemia with secondary bleeding diathesis. Treatment with prednisone and chlorambucil was initiated, and the dog had a good response.

Presumed primary muscular lymphoma in a dog.

A case of presumed primary muscular lymphoma in an 8-year-old, intact, male Newfoundland dog is reported. The dog was presented for evaluation of an infiltrating ventral cervical mass, respiratory distress, and anorexia of 1-month duration. Fine-needle aspiration of the mass revealed anaplastic large cell lymphoma. Despite chemotherapy, health status declined and the animal was euthanized a few weeks later. At necropsy, the mass infiltrated the cervical muscles and extended ventrally to the left forelimb and cranially to the tongue and laryngeal musculature. Other muscles were infiltrated by the same neoplasm (diaphragm and intercostal, abdominal, and gluteal muscles) indicating a probable multicentric origin. Histological examination confirmed the diagnosis of anaplastic large cell lymphoma, which showed a strong muscular tropism. Immunohistochemical staining revealed neoplastic cell reactivity for cluster of differentiation 3 (CD3) and Ki-67 antigens (70% and 90%, respectively). The neoplastic cells were negative for CD79a. The presumed histological diagnosis in this dog was primary muscular anaplastic large T-cell lymphoma.

Acute megakaryoblastic leukemia with erythrophagocytosis and thrombosis in a dog.

A 7-year-old, intact male Dachshund was presented to the Lyon veterinary school for lethargy and anorexia of several weeks duration. The main clinical signs were pale and icteric mucous membranes, hepatomegaly, splenomegaly, and lymphadenopathy. Results of a CBC and plasma biochemistry tests revealed severe nonregenerative anemia, thrombocytopenia, and increased alanine aminotransferase and alkaline phosphatase activities. Blood smear evaluation and cytologic examination of lymph node and bone marrow aspirate specimens revealed a large population of poorly differentiated blast cells with morphologic features suggesting megakaryocytic lineage. A low number of well-differentiated but dysplastic megakaryocytes also were observed in lymph node and bone marrow smears. A few blast cells were erythrophagocytic. Blast cells were positive for glycoprotein IIIa, factor VIII-related antigen, and factor XIII using immunocytochemistry. The dog was euthanized and necropsied. Histologic findings consisted of diffuse, massive infiltration of lymph nodes, liver, and spleen by megakaryoblasts and atypical megakaryocytes, with widespread thrombosis. This case confirms the usefulness of immunochemistry, including for factor XIII, in the diagnosis of megakaryoblastic leukemia, and demonstrates the unique features of tumor cell erythrophagocytosis and marked fibrinous thrombosis, which have not been reported previously in dogs.

Prognostic significance of morphological subtypes in canine malignant lymphomas during chemotherapy.

The aim of this study was to determine the response of different morphological subtypes of canine lymphoma to a standardized therapeutic protocol. Diagnosis of lymphoma was based on cytohistological analysis and immunophenotyping with antibodies against CD3 and CD79a of an enlarged lymph node or an extranodal mass. Fifty-seven cases were classified according to the updated Kiel classification adapted to the canine species, into 24 B-cell lymphomas (20 centroblastic polymorphic and four Burkitt-type subtypes), and 33 T-cell lymphomas (10 pleomorphic mixed, 10 lymphoblastic, eight unclassifiable high grade plasmacytoid, and five small clear-cell subtypes). All dogs were clinically staged at diagnosis. The protocol used l-asparaginase, vincristine, cyclophosphamide, doxorubicin, and prednisone. First remission duration and overall survival time were evaluated. Although the T-cell phenotype was associated, on the whole, with a poor prognosis, as previously reported in veterinary and human medicine, the study showed significant prognostic differences between the B- and the T-cell subtypes of canine lymphoma and suggests that clinico-morphological characterization of the disease is justified in dogs, as in humans.