Hematological and biochemical profiles of canine CD45− T lymphomas are different from other immunophenotypes

Abstract

Background: Canine multicentric lymphomas are lymphoproliferative malignancies that have increased in recent decades. The patient’s treatment and prognosis are determined by the grade, histological type, and lymphoma immunophenotyping.

Aim: To investigate the paraclinical signs and survival time in canines with different lymphoma immunophenotypes.

Methods: Over 2 and a half years, 47 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⁻). The patients’ haematological values, calcemia, lactate dehydrogenase (LDH) levels, and plasmatic electrophoretic profiles were all determined immediately after that.

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 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. Only the TCD45⁺ group had hypercalcemia although both the LB and TCD45⁺ groups had elevations in LDH activity. 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 more prolonged survival. Serum LDH activity may provide additional prognostic information in high-grade T-cell lymphoma.