Clinical and Clinical Pathological Presentation of 310 Dogs Affected by Lymphoma with Aberrant Antigen Expression Identified via Flow Cytometry

Abstract

Phenotypic aberrancies have been reported occasionally in canine lymphomas. Here, we retrospectively collected 310 canine lymphomas with an aberrant phenotype detected via flow cytometry and describe their clinical and clinical pathological features at diagnosis. There were 152 T-cell lymphomas not otherwise specified (T-NOS), 101 T-zone lymphomas (TZL), 54 B-cell lymphomas, and 3 cases with two suspected concurrent neoplastic populations. The most represented aberrancies were: CD5-, CD4-CD8-, and CD3- in T-NOS lymphomas, CD21+, CD4-CD8-, and CD3- in TZLs, and CD34+, CD44-, and CD5+ in B-cell lymphomas. Among T-cell lymphomas, the aberrant expression of CD21 was significantly more frequent in TZL and the loss of CD5 and CD44 in T-NOS. More than 75% of dogs were purebred; males outnumbered females; the mean age at diagnosis was 8–10 years, depending on lymphoma subtype. A few dogs were symptomatic at the time of diagnosis, and 30% had peripheral blood abnormalities, in line with what is already reported for the general population of dogs with lymphoma. Further studies are needed to assess the pathogenetic mechanisms underlying each specific antigen aberrancy, as well as the diagnostic and prognostic role.

Whole Genome 3D Blood Biopsy Profiling of Canine Cancers: Development and Validation of EpiSwitch Multi-Choice Array-Based Diagnostic Test

“…The protein network for canine TZL, for example, shows a key group of modulated proteins, such as ESR1, GATA4, CD44, CRBP1, ACTA1 (Figure 6), all consistent with the human T-cell NHL cases [79][80][81] .…”

Comparative analysis of the aberrant immunophenotype and clinical characteristics in dogs with lymphoma: a study of 27 cases

“…The possibility of TZL originating from the tongue is also high in this dog, considering a previous case of TZL in the tongue ( 32 ). However, in another study, 5.3% of T-cell not otherwise specified dogs were identified as CD45- ( 20 ). Although this study did not find any aggressive lymphoma with CD45-, it is expected that the frequency of this aberrant type will increase as the population size increases.…”

“…Previous studies have reported a slight difference in the incidence of aberrant phenotypes depending on the definition used. Specifically, Celant et al found that 12% (310/2,612) of dogs had specific antigen aberrancies ( 20 ), while Wilkerson et al reported an incidence of 22% ( 5 ). The incidence of loss of MHCII expression or low expression, which was the most frequently identified aberrancy in our study, has been reported to be approximately 14–72% in previous studies ( 2 , 11 ).…”

“…The incidence of loss of MHCII expression or low expression, which was the most frequently identified aberrancy in our study, has been reported to be approximately 14–72% in previous studies ( 2 , 11 ). Additionally, the co-expression of CD3 and CD21 has been reported to range from as low as 0.7% ( 20 ), to as high as 31–50% ( 5 , 19 ), while one study reported no cases of CD3/CD21 co-expression ( 26 ).…”

Flow Cytometric Features of B- and T-Lmphocytes in Reactive Lymph Nodes Compared to Their Neoplastic Counterparts in Dogs

“…They appear to be CD45+ T-cells because of the concomitant expression of CD3 ( Figure S2 ) and warrant further consideration. First, the co-expression of these two markers should not always be considered aberrant and thus diagnostic for neoplasia, as was the case in the past [ 20 , 21 ]. Second, the nMFI of both CD5 and CD21 was different from those of the remaining small cells, further supporting the distinct nature of CD5+CD21+ cells.…”