Abstract
Abstract
Background: Canine multicentric lymphomas are lymphoproliferative malignancies that have increased in recent decades. Treatment and life expectancy of the patient depend on the grade, histological type, and the lymphoma immunophenotyping.
Aim: To investigate the paraclinical signs and survival time in canines with different lymphoma immunophenotypes.
Methods: Over two and a half years, forty-seven untreated dogs were diagnosed with multicentric lymphoma at the Veterinary School Hospital of Uruguay. The disease was clinically and cytologically diagnosed, and immunophenotyping was determined by flow cytometry. After the immunophenotyping, most of the patients were grouped into the following: B (LB), T aggressive (LTCD45+), or T-zone lymphoma (LTCD45-). Immediately after, the patients' hematological values, Calcemia, LDH levels, and plasmatic electrophoretic profiles were determined.
Results: Of all canine lymphomas, 55.3% were B, 31.9% were LTCD45+, and 10.6% were TCD45-. Only 2.2% were classified as nonB/nonT, and survival time differed between groups. Patients with LTCD45- lymphomas had a mean life span of 641 days after diagnosis, followed by LB (166 days) and LTCD45+ (62 days). Red blood cell count, hematocrit, and hemoglobin levels did not differ between groups. However, the LTCD45- group had significantly higher lymphocyte levels than the LTCD45+ and LB groups (P=0.01 and P=0.006, respectively). Levels of albumin, alpha-1 and alpha-2 globulins did not differ between groups. On the other hand, gamma globulins levels in the LTCD45- were higher than in the other lymphoma groups. The presence of hypercalcemia and high plasma LDH levels were associated with patient severity. Hypercalcemia was only observed in the TCD45+ group, whereas increases in LDH activity were observed in the LB and TCD45+ groups. Interestingly, there was a direct relationship between high LDH values (greater than 500 IU/L) and lower survival in TCD45+ lymphomas.
Conclusion: Survival time, and hematological and biochemical patterns differed among canine lymphomas immunophenotypes. Patients of LTCD45- phenotype showed higher lymphocyte counts and gamma globulin levels and longer survival. Serum LDH activity may provide additional prognostic information in high grade T cell lymphoma.

Key words: dogs, immunophenotype, multicentric lymphoma, paraneoplastic syndromes, survival times.