Factors correlating with circulating T-zone-like cells of undetermined significance (TZUS) in dogs resident in Italy

T-zone-like cells of undetermined significance (TZUS) share the same phenotypic pattern (CD45-CD5+) with T-zone lymphoma cells and were first described a few years ago in the peripheral blood (PB) of healthy aged American Golden retrievers (GR). History of bladder and eye disease increased the odd of circulating TZUS in the American GR population. Since differences among dogs may exist according to the geographical region of origin, herein we screened 489 PB samples to assess potential factors predisposing to the presence of circulating TZUS in dogs living in Italy. Overall, TZUS were found in 174 (35.6%) samples. Among 83 clinical variables, significant associations emerged with sex, age, diagnosis of neoplasia, history of neoplasia, history of infectious or parasitic disease, history of osteoarticular disease, presence of traumatic lesions or foreign bodies, and lymphocytes count. Only age and history of neoplasia retained significance at multivariate analysis (p=0.019 and p=0.036, respectively). Thus, older age and history of neoplasia are the main factors associated with circulating TZUS in Italian dogs. Future studies should focus on elucidating the biological role of TZUS and determining reproducible criteria for their identification, distinguishing them from infiltrating TZL.

Can peri-surgical electroacupuncture relieve immunity suppression? A pilot study in dogs

General anesthesia and surgical stress can suppress the immunological response by acting both directly on the immune system and indirectly on the hypothalamic-pituitary-adrenal axis and the sympathetic nervous system. Disturbance of the immune system during the perioperative period can lead to complications such as wound-healing disorders and infections up to sepsis. Effectiveness of acupuncture in regulating the immune function by increasing leukocyte numbers and inhibiting inflammatory response has been proven. This study aimed to explore the impact of electroacupuncture (EAP) on the dynamic balance of the immune system and immune cell populations in dogs undergoing surgery. Twelve healthy bitches scheduled for elective ovariectomy were divided into two groups according to whether (EAP, n=6) or not (CTR, n=6) a peri-operative electroacupuncture treatment was performed. Levels of leukocytes (neutrophils, monocytes, T- and B-cells) and immunoglobulins M (IgM) and A (IgA) were measured in blood samples collected before (T0), 1hour (T1) and 2.5hours (T2) after anesthesia induction. Leukocytes count decreased from T0 to T1 in both groups and restored within 1.5hours in EAP group whereas remained significantly lower in CTR group (P<0.02). In particular, neutrophils and monocytes increased in dogs receiving EAP (P<0.01) while T-cells decreased in CTR group (P<0.04) at T2. B-cells and cytotoxic T-cells decreased in EAP dogs (P<0.04) at T2. No differences in helper T-cells, IgM and IgA levels were recorded between groups and over time. Our results suggest a modulatory effect of EAP on the immune system which is early expressed on neutrophils, monocytes and T-cells.

Content analysis of Reddit posts about coadministration of selective serotonin reuptake inhibitors and psilocybin mushrooms

RATIONALE

Treatments with the serotonergic psychedelic psilocybin are being investigated for multiple neuropsychiatric disorders. Because many patients with these disorders use selective serotonin reuptake inhibitors (SSRIs), understanding interactions between psilocybin and SSRIs is critical for evaluating the safety, efficacy, and scalability of psilocybin-based treatments. Current knowledge about these interactions is limited, as most clinical psilocybin research has prohibited concomittant SSRI use.

OBJECTIVES

We aimed to explore potential interactions between psilocybin and SSRIs by characterizing peoples' real-world experiences using psilocybin mushrooms and SSRIs together.

METHODS

We conducted a systematic search of Reddit for posts describing psilocybin mushroom and SSRI coadministration. We identified 443 eligible posts and applied qualitative content analysis to each.

RESULTS

8% of posts reported negative physical or psychological effects resulting from coadministration. These included 13 reports that may reflect serotonin toxicity, and 1 concerning for a psychotic/manic episode. 54% of posts described reduced intensity of the acute psilocybin experience, but 39% reported unchanged intensity with SSRI coadministration.

CONCLUSIONS

Psilocybin's interactions with SSRIs are likely complex and may depend on multiple factors. Prospective studies are needed to evaluate whether psilocybin treatments are reliably safe and effective in the setting of SSRI use.

Automated hematological cell count using sysmex XN-1000V in Testudo hermanni: Agreement with manual count

Mediterranean area represents the main habitat of Testudo hermanni. Clinical signs of disease of these tortoises are non-specific, making the hematology results crucial in revealing underlying pathological conditions. However, accurate automated identification of blood cell populations is hampered by the presence of nucleated erythrocytes (NRBC) and thrombocytes (Thr), necessitating manual methods such as counting chambers. The aim of the study was to assess the performance of the novel automated hematology analyzer Sysmex XN-1000 V, which includes a a specific channel (WNR) for counting NRBC, in accurately identify and quantify the different blood cell populations of Testudo hermanni. Additionally, its agreement with manual counts was evaluated. Fifty heparinized blood samples were initially counted using the Neubauer improved chamber and then analysed twice with Sysmex XN-1000 V. Thirteen out of 50 samples were instrumentally counted again after 48 h to assess the inter-assay precision. All WNR scattergrams were re-analysed using an ad hoc gate panel to differentiate two populations: NRBCs (weak fluorescence signal) and WBC + Thr (high fluorescence signal). Sysmex XN-1000 V demonstrated optimal intra- and inter-assay precision for NRBCs (CV 0.98% ± 1.96; 1.31% ± 2.98) and moderate precision for WBC + Thr (CV 9.24% ± 16.61; 12.69% ± 10.35). No proportional nor constant errors were observed between the methods for both the populations. The instrumental NRBC counts were consistently slightly lower, while WBC + Thr counts were slightly higher compared to manual counts. These findings suggest that Sysmex XN-1000 V can be used for analyzing cell populations in heparinized blood of Testudo hermanni. However, specific instrumental reference intervals are suggested.

Alcohol mixed with energy drinks and aggressive behaviors in adolescents and young adults: A systematic review

PURPOSE

Consuming alcohol mixed with energy drinks (AmED) is a high-risk drinking practice. This systematic review examines how AmED use contributes to aggression (physical and sexual), in what role(s) (perpetrator and/or victim), in adolescents and young adult drinkers (age 25 and younger).

METHODS

Computer assisted search identified 844 studies conducted prior to March 2023; of them 17 met inclusion criteria.

RESULTS

AmED use was significantly associated with aggressive behaviors. Between-subject studies suggests that AmED consumers have higher rates of perpetration (physical fights, bullying) and victimization compared to peers who only drink alcohol; however, within-subject studies of AmED users find no difference in physical aggression by drinking event (AmED vs. occasions where consumer drinks alcohol only). Similarly, AmED use was a risk factor for sexually aggressive behaviors (e.g., unwanted contact) and victimization.

CONCLUSIONS

AmED use is a significant risk factor both victimization and perpetration of violent acts. Differences in within- versus between-study findings suggests that risk is associated with use of AmED, and not event level differences in drinking occasions among AmED users. Findings highlight the relative paucity of studies examining victimization and sexual violence and the need for future studies to incorporate more diverse samples and methodologies to better understand patterns of AmED use, perpetration, and victimization.

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

An in-depth knowledge of non-neoplastic patterns is fundamental to diagnose neoplasia. In the present study, we described the flow cytometric (FC) cell size (FSC) and fluorescence intensity (MFI) of B- and T-lymphocytes in 42 canine reactive lymph nodes and 36 lymphomas. Proliferative activity (Ki67%) in reactive lymph nodes was also reported. Reactive lymph nodes were composed of a mixed population of small and large T (CD5+) and B (CD21+) cells. Small T-cells were larger in size than small B-cells, and large T-cells were larger than large B-cells. Small T-cells were composed of CD5+CD21- and CD5+CD21+dim subpopulations. Large B-cells were <20% in reactive lymph nodes and >20% in lymphomas and showed a higher FSC in lymphomas than in reactive lymph nodes. Large T-cells were <4% in reactive lymph nodes and >4% in lymphomas and showed a higher CD5 MFI in lymphomas (if expressed) compared to reactive lymph nodes. A subset of CD5+CD21+dim lymphocytes was recognized in addition to CD5+CD21- and CD5-CD21+ cells. In T-zone lymphomas, neoplastic cells had higher FSC and CD21 MFI values than small CD5+CD21+dim cells in reactive lymph nodes. Ki67% values were higher than those reported in normal lymph nodes, and largely overlapped with those reported in low-grade lymphomas and partially in high-grade lymphomas. Our results may contribute to making a less operator-dependent FC differential between lymphoma and reactive lymph nodes.

Waldenström's Macroglobulinemia in a Normoproteinemic Dog with Atypical Bimorphic Plasmacytoid Differentiation and Monoclonal Gammopathy

A 2-year-old neutered female Small Munsterlander dog was presented for an insect bite. Physical examination revealed a poor body condition, a peripheral lymphadenomegaly, and suspected splenomegaly. A complete blood count (Sysmex XN-V) revealed marked leukocytosis with lymphocytosis and abnormal dot plots. An abnormal monomorphic lymphoid population and marked rouleaux formation were noted on the blood smear. Lymph node aspirates contained an atypical bimorphic population of lymphocytes, either with a plasmacytoid or a blastic appearance. This double population was also found in the spleen, liver, bone marrow, tonsils, and other tissues. Peripheral blood and lymph node clonality assays revealed clonal BCR gene rearrangement. Flow cytometry revealed a mixed population of small-sized B-cells (CD79a+ CD21+ MHCII+) and medium-sized B-cells (CD79a+ CD21- MHCII-) in lymph nodes and a dominant population of small-sized mature B-cells (CD21+ MHCII+) in peripheral blood. Though normoproteinemic, serum protein electrophoresis revealed an increased α2-globulin fraction with an atypical restricted peak, identified as monoclonal IgM by immunofixation. Urine protein immunofixation revealed a Bence-Jones proteinuria. A diagnosis of Waldenström's macroglobulinemia was made. Chemotherapy was initiated, but the dog was euthanized 12 months after the initial presentation due to marked clinical degradation.

A method to test antibody cross-reactivity toward animal antigens for flow cytometry

The availability of cross-reacting antibodies and/or of antibodies working in flow cytometry is a major issue in the veterinary field. One of the main problems is the availability of certain positive controls. With this brief communication, we report an method to quickly screen a wide number of products without the need to look for positive biological samples. We propose this approach as a first step to select the best antibodies to test on biological specimens.

Gut Microbiota and Lymphocyte Subsets in Canine Leishmaniasis

Gut microbiota seems to interact with immune system. Canine leishmaniasis pathogenesis and severity of disease lean on the host immunity, but there is no information in literature about gut microbiota in infected animals. Thus, this study aims to compare the microbiota composition and leukocyte subset of healthy dogs with those of asymptomatic dogs exposed to Leishmania spp. and dogs with clinical leishmaniasis. Thirty-nine dogs were enrolled and grouped into three groups: healthy, exposed asymptomatic and infected symptomatic for Leishmania spp. Flow cytometry on whole blood evaluated the prevalence of CD4, CD5, CD8, CD11b, CD14, and CD21 positive cells. Gut microbiota was investigated using a next generation sequencing (NGS) technique. Firmicutes resulted significantly more abundant in the healthy dogs compared with the other two groups. Conversely, Proteobacteria were more abundant in symptomatic dogs. Even in rarest phyla comparison some significant differences were found, as well as in comparison at classes, order, family and genus levels. The symptomatic group had lower concentration of all the lymphocyte classes (CD5, CD21, CD4, CD8) compared to the other groups. A lower abundance of Firmicutes is reported in literature in diseased animals compared to the healthy ones and this is in agreement with the results of this study. Increased Proteobacteria in sick animals could suggest a dysbiosis status, even without distinct gastrointestinal signs. The leukocyte classes results indicate a decreased Th1 response in symptomatic dogs. Studies also investigating the cytokine response could deepen the knowledge on the pathogenesis of canine leishmaniasis.

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

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.

Performance of lymph node cytopathology in diagnosis and characterization of lymphoma in dogs

BACKGROUND

Cytopathology is a minimally invasive and convenient diagnostic procedure, often used as a substitute for histopathology to diagnose and characterize lymphoma in dogs.

OBJECTIVES

Assess the diagnostic performance of cytopathology in diagnosing lymphoma and its histopathological subtypes in dogs.

ANIMALS

One-hundred and sixty-one lymph node samples from 139 dogs with enlarged peripheral lymph nodes.

METHODS

Based only on cytopathology, 6 examiners independently provided the following interpretations on each sample: (a) lymphoma vs nonlymphoma; (b) grade and phenotype; and (c) World Health Organization (WHO) histopathological subtype. Histopathology and immunohistochemistry (IHC) findings were used as reference standards to evaluate diagnostic performance of cytopathology. Clinical, clinicopathologic, and imaging data also were considered in the definitive diagnosis.

RESULTS

Classification accuracy for lymphoma consistently was >80% for all examiners, whereas it was >60% for low grade T-cell lymphomas, >30% for high grade B-cell lymphomas, >20% for high grade T-cell lymphomas, and <40% for low grade B-cell lymphomas. Interobserver agreement evaluated by kappa scores was 0.55 and 0.32 for identification of lymphoma cases, and of grade plus immunophenotype, respectively.

CONCLUSIONS AND CLINICAL IMPORTANCE

Cytopathology may result in accurate diagnosis of lymphoma, but accuracy decreases when further characterization is needed. Cytopathology represents a fundamental aid in identifying lymphoma and can be used as a screening test to predict grade and phenotype. However, these results must be confirmed using other ancillary techniques, including flow cytometry, histopathology, and immunohistochemistry (IHC).

Prognostic Value of PD-L1, PD-1 and CD8A in Canine Diffuse Large B-Cell Lymphoma Detected by RNAscope

Immune checkpoints are a set of molecules dysregulated in several human and canine cancers and aberrations of the PD-1/PD-L1 axis are often correlated with a worse prognosis. To gain an insight into the role of immune checkpoints in canine diffuse large B-cell lymphoma (cDLBCL), we investigated PD-L1, PD-1 and CD8A expression by RNAscope. Results were correlated with several clinico-pathological features, including treatment, Ki67 index and outcome. A total of 33 dogs treated with chemotherapy (n = 12) or chemoimmunotherapy with APAVAC (n = 21) were included. PD-L1 signal was diffusely distributed among neoplastic cells, whereas PD-1 and CD8A were localized in tumor infiltrating lymphocytes. However, PD-1 mRNA was also retrieved in tumor cells. An association between PD-L1 and PD-1 scores was identified and a higher risk of relapse and lymphoma-related death was found in dogs treated with chemotherapy alone and dogs with higher PD-L1 and PD-1 scores. The correlation between PD-L1 and PD-1 is in line with the mechanism of immune checkpoints in cancers, where neoplastic cells overexpress PD-L1 that, in turn, binds PD-1 receptors in activated TIL. We also found that Ki67 index was significantly increased in dogs with the highest PD-L1 and PD-1 scores, indirectly suggesting a role in promoting tumor proliferation. Finally, even if the biological consequence of PD-1+ tumor cells is unknown, our findings suggest that PD-1 intrinsic expression in cDLBCL might contribute to tumor growth escaping adaptive immunity.

Tumor staging in a Beagle dog with concomitant large B-cell lymphoma and T-cell acute lymphoblastic leukemia

An 8-y-old spayed female Beagle dog was presented with peripheral lymphadenomegaly. Lymph node cytology and flow cytometry led to the diagnosis of large B-cell lymphoma (LBCL). We detected minimal percentages of LBCL cells in peripheral blood and bone marrow samples. However, a monomorphic population of neoplastic cells different from those found in the lymph node was found in the bone marrow. T-cell acute lymphoblastic leukemia was suspected based on flow cytometric immunophenotyping. PCR for antigen receptor rearrangement (PARR) revealed clonal rearrangement of both B-cell and T-cell receptors, and the presence of both neoplastic clones in the lymph node, peripheral blood, and bone marrow. The dog was treated with multi-agent chemotherapy but died 46 d following diagnosis. Tumor staging and patient classification are needed to accurately establish a prognosis and select the most appropriate therapeutic protocol.

Vr exposure in cbt is effective and efficacious treatment for simple phobia (flight phobia)

Introduction

The virtual environment with realistically rendered fear-inducing stimuli is enough to conduct VR exposure therapy (VRE), although the total control over the virtual environment also enables presentation of stimuli, contexts, and tasks not possible in in vivo exposure therapy (i.e. flight etc.)30 randomized controlled trials revealing high efficacy and effect sizes comparable of VRE-CBT to in vivo exposure therapy. Aerophobia is a very frequent limitation and affect 25% of the population and 30% of the subjects who fly make habitual use of anxiolytics.

Objectives

The aims of this study is to show that conducting VR exposure in CBT for simple phobia (flight phobia) is effective and is an efficacious treatment for fear and anxiety,Vs other treatments.

Methods

Participants (n = 39; age between 19 and 60 years) in the active arms received individual CBT VR exposure for six sessions and outcome was assessed with questionnaires: MSPS;Rathus Assertiveness Scale (RAS); HAM-A; QMAV; QSAV – (Flying fear); QoL INDEX and a behaviour avoidance test (really take the plane). Wilcoxon tests was using for the statistical analysis.

Results

36 subjects managed to take the plane at the end of treatment and the results obtained showed a significant difference between “before treatment (T0) and after (T1)” with the exception of the Rathus test. All the SF-36 scales show a significant difference between “before-after”. 3 subjects was dropped out

Conclusions

Using VR can be advantageous over standard CBT as a potential solution for treatment avoidance and as an efficient, cost-effective and practical medium of exposure.

Disclosure

No significant relationships.

Phenotypical Characterization and Clinical Outcome of Canine Burkitt-Like Lymphoma

In dogs, Burkitt-like lymphoma (B-LL) is rare tumor and it is classified as a high-grade B-cell malignancy. The diagnosis is challenging because of the similar histologic appearance with other histotypes, no defined phenotypical criteria and poorly described clinical aspects. The aim of the study was to provide a detailed description of clinical and morphological features, as well as immunophenotypical profile of B-LL in comparison with the human counterpart. Thirteen dogs with histologically proven B-LL, for which a complete staging and follow-up were available, were retrospectively selected. Immunohistochemical expression of CD20, PAX5, CD3, CD10, BCL2, BCL6, MYC, and caspase-3 was evaluated. Histologically, all B-LLs showed a diffuse architecture with medium to large-sized cells, high mitotic rate and diffuse starry sky appearance. B-phenotype of neoplastic cells was confirmed both by flow-cytometry and immunohistochemistry. Conversely, B-LLs were negative for BCL2 and MYC, whereas some cases co-expressed BCL6 and CD10, suggesting a germinal center B-cell origin. Disease stage was advanced in the majority of cases. All dogs received CHOP-based chemotherapy with or without immunotherapy. Despite treatment, prognosis was poor, with a median time to progression and survival of 130 and 228 days, respectively. Nevertheless, ~30% of dogs survived more than 1 year. An increased apoptotic index, a high turnover index and caspase-3 index correlated with shorter survival. In conclusion, canine B-LL shows phenotypical differences with the human counterpart along with features that might help to differentiate this entity from diffuse large B-cell lymphoma.

Cytology of Feline Nodal Lymphoma: Low Interobserver Agreement and Variable Accuracy in Immunophenotype Prediction

Nodal lymphomas are less common in cats than in dogs and, consequently, no specific studies have been published. Cytology is the first step in the diagnosis of nodal lymphoma but is highly subjective. Morphological features have been introduced for the cytological classification of canine lymphomas but not for cats. Therefore, the aim of this study was to evaluate interobserver agreement on various cytological features of feline nodal lymphomas and to investigate the accuracy in predicting B or T immunophenotypes. Four veterinary cytologists examined 25 feline nodal and mediastinal lymphoma cytological samples by adapting the criteria used for the evaluation of canine lymphomas and setting histopathology and immunohistochemistry as the gold standard. High interobserver variability was found in the evaluation of most features except for the presence or absence of cytoplasmic vacuoles, which were more common in B-cell lymphomas. Cytology training centre was the major factor influencing the extent of agreement among evaluators. Diagnostic accuracy in predicting lymphoma immunophenotype varied from 35% to 75% and did not appear to be correlated with the experience of the evaluators. We conclude that cytological criteria, commonly used to describe canine lymphomas, are not adaptable to the counterpart feline neoplasms. Cytology-based immunophenotyping of feline lymphomas from different laboratories, and different cytologists within the same laboratory, differ substantially and should not be considered reliable. Specific cytological criteria are needed to describe feline lymphoma.

Flow Cytometric Analysis of Mediastinal Masses in Cats: A Retrospective Study

Mediastinal masses occur in dogs and cats and are often investigated with cytology. However, discrimination between the two most common lesions (thymoma and lymphoma) may be challenging, especially when small/medium lymphocytes represent the prevalent population. The aim of the present study is to describe the flow cytometric aspects of mediastinal masses in cats and to assess the ability of flow cytometry (FC) to differentiate lymphoma from non-lymphomatous lesions. We retrospectively describe FC features of fine needle aspiration cytology from cats with mediastinal masses. Cases were grouped in lymphoma and non-lymphoma based on results of cytology, histopathology, PCR for antigen receptor rearrangement (PARR), clinical presentation, and follow-up. Scatter properties, positivities to CD5, CD4, CD8, CD21, CD18, and their co-expressions were recorded using a multicolour approach. Twenty cats were included, 12 lymphomas and eight non-lymphomatous cases. Forward scatter (FSC) of lymphoid cells was higher in the lymphoma group. Double positive CD4+CD8+ T-cells were the dominant population in eight out of 12 lymphomas, whereas non-lymphomatous lesions showed no dominant lymphoid population in five out of eight cases. Unlike dogs, the high prevalence of CD4+CD8+ lymphomas in cats it makes difficult to differentiate lymphoma from non-lymphomatous lesions using FC alone. FC may add interesting information to refine diagnosis in some cases, but PARR and histopathology remain mandatory to solve differential in case of expansion of small–medium sized double positive lymphoid cells.

Flow cytometry expression pattern of CD44 and CD18 markers on feline leukocytes

The paucity of specific feline antibodies for flow cytometry (FC) is an ongoing challenge. Flow cytometrists must extrapolate information from relatively few markers. We evaluated the expression pattern of the panleukocyte markers CD18 and CD44 on leukocyte (white blood cell, WBC) subclasses in the peripheral blood (PB) of 14 healthy cats. The degree of expression of CD18 and CD44 was calculated as the ratio between the median fluorescence intensity (MFI) value of antibody-stained cells and autofluorescence. All samples were acquired with the same cytometer with constant photomultiplier setting and compensation matrices. Both molecules were expressed at higher levels on monocytes, intermediate levels on polymorphonuclear cells (PMNs), and lower levels on lymphocytes. CD18-MFI discriminated well among the 3 populations, whereas CD44-MFI mostly overlapped between monocytes and PMNs. However, CD44-MFI had a lower intra-population variability. Evaluation of CD18 and CD44, together with morphologic parameters, was useful for discriminating among WBC subclasses in healthy cats. This information may be helpful for future studies given that an increase in CD18-MFI may indicate reactive changes, whereas fluctuations in CD44-MFI may suggest neoplasia.

Immune-complex glomerulonephritis in cats: a retrospective study based on clinico-pathological data, histopathology and ultrastructural features

Background

Chronic kidney disease (CKD) has typically a non-immune mediated origin in cats and immune-complex glomerulonephritis (ICGN) is scarcely described. Aims of this study were to characterize ICGN by light and electron microscopy and identify associations with clinico-pathological findings. In addition, comparisons between cats with ICGN and non immune-complex glomerulonephritis (non-ICGN) were performed.

Renal samples examined between 2010 and 2019 were considered if both light and electron microscopy were performed. Signalment, feline immunodeficiency virus (FIV) and leukemia virus (FeLV) status, serum creatinine concentration, urine protein-to-creatinine (UPC) ratio, systolic blood pressure (SBP) and International Renal Interest Society (IRIS) stage were retrieved and used for comparisons.

Results

Sixty-eight client-owned cats were included. Thirty-seven cats (54.4%) had ICGN and 31 (45.6%) non-ICGN. Eighteen (48.6%) with ICGN had membranous glomerulonephropathy (MGN), 14 (37.8%) membranoproliferative glomerulonephritis (MPGN), and 5 (13.5%) mesangioproliferative glomerulonephritis (MeGN). Clinico-pathological data were not associated with any type of ICGN. Among cats with non-ICGN, 11 (35.5%) had end-stage CKD, 9 (29%) focal segmental glomerulosclerosis, 6 (19.4%) global and multifocal mesangiosclerosis, 2 (6.5%) glomerular atrophy, 2 (6.5%) renal dysplasia and 1 (3.1%) amyloidosis. Eight (25.8%) cats with non-ICGN had chronic interstitial nephritis (CIN) grade 1, 13 (41.9%) grade 2 and 10 (32.3%) grade 3; creatinine and UPC ratio increased with CIN grades (p = 0.001, p < 0.001). Cats with ICGN were more frequently FIV or FeLV-infected (OR:11.4; 95%CI:1.4–94.4; p = 0.024), had higher UPC ratio (OR:6.8; 95%CI:2.5–18.2; p < 0.001) and were younger (OR:0.9; 95%CI:0.7–1.0; p = 0.042) than cats with non-ICGN.

Conclusions

MGN and MPGN were the most common morphological diagnoses of ICGN in cats. Unfortunately, none of the investigated findings differentiated ICGN morphological diagnoses. Serum creatinine concentration and UPC ratio were directly associated with grades of CIN (p = 0.001 and p < 0.001, respectively), confirming previous literature. More ICGN than non-ICGN was observed in cats with retroviral infections, younger cats and higher UPC ratio.

Prognostic role of non-neoplastic lymphocytes in lymph node aspirates from dogs with diffuse large B-cell lymphoma treated with chemo-immunotherapy

Dogs with Diffuse Large B-Cell Lymphoma (DLBCL) benefit from the addition of active immunotherapy to traditional chemotherapy. We hypothesized that immune cells within neoplastic lymph nodes (LNs) may play a role in the tumor pathobiology and treatment response. The present study describes the composition and prognostic role of non-neoplastic lymphocytes in LNs of 59 dogs with treatment-naive DLBCL receiving chemo-immunotherapy. The percentage of small non-neoplastic cells and of CD5+, CD21+, CD4+ and CD8+ small cells was recorded via flow cytometry. CD4+/CD8+ and CD5+/large CD21+ cell ratios were calculated. The likelihood of progression significantly diminished with increasing percentage of small cells, CD5+ and CD8+ small cells, and CD5+/large CD21+ cell ratio, with decreasing CD4+/CD8+ ratio and in non-anemic dogs. Active immunotherapy is more effective in dogs with higher percentage of non-neoplastic lymphocytes at diagnosis. We lay the ground for future studies assessing the role of the immune system in the pathobiology of canine DLBCL.

Opportunities and challenges of active immunotherapy in dogs with B-cell lymphoma: a 5-year experience in two veterinary oncology centers

BACKGROUND

Pet dogs spontaneously develop lymphoma. An anthracycline-based multidrug chemotherapy regimen represents the treatment cornerstone; however, cure is rarely achieved. We have been treating dogs with B-cell lymphoma with an autologous vaccine (APAVAC®) and CHOP-based chemotherapy since 2011.

METHODS

To better characterize the safety and efficacy of APAVAC®, and to find the best candidates for immunotherapy, we designed a retrospective study on all dogs treated with chemo-immunotherapy to date and compared them with those dogs treated with chemotherapy only. All dogs were completely staged and re-staged at the end of treatment. The primary endpoint was the effectiveness of chemo-immunotherapy, measured as time to progression (TTP), lymphoma-specific survival (LSS), and 1-, 2-, and 3-year survival rates. The secondary objective was safety.

RESULTS

Three hundred dogs were included: 148 (49.3%) received chemotherapy and 152 (50.7%) chemo-immunotherapy. Overall, the latter survived significantly longer (median LSS, 401 vs 220; P <  0.001). Among dogs with diffuse large B-cell lymphoma, the 1-, 2- and 3-year survival rates were 20, 13 and 8% for chemotherapy, and 51, 19 and 10% for chemo-immunotherapy. The benefit of chemo-immunotherapy was particularly relevant in dogs with concurrent high serum LDH, stage V, substage a disease and not previously treated with steroids (median LSS, 480 vs 85 days; P <  0.001). Among dogs with nodal marginal zone lymphoma, those having at least 3 of the aforementioned characteristics significantly benefited from chemo-immunotherapy (median LSS, 680 vs 160 days, P <  0.001). The 1-, 2- and 3-year survival rates were 30, 16 and 10% for chemotherapy, and 55, 28 and 10% for chemo-immunotherapy. Among dogs with follicular lymphoma, lack of immunotherapy administration was the only variable significantly associated with increased risk of tumor-related death. Chemo-immunotherapy was remarkably well tolerated, with no local or systemic adverse events.

CONCLUSIONS

Overall, the addition of immunotherapy to a traditional CHOP protocol is associated with improved outcome in dogs with B-cell lymphoma, regardless of histotype and evaluated prognostic factors. Moreover, the identikit of the best candidate for immune-therapy was delineated for the most common histotypes. The study also confirms the excellent tolerability of the vaccine.

Blood lymphocyte subpopulations in healthy water buffaloes (Bubalus bubalis, Mediterranean lineage): Reference intervals and influence of age and reproductive history

There is an increasing interest toward infectious diseases and mechanisms of immune response of water buffaloes, mainly because of the growing economic impact of this species and of its high-quality milk. However, little is known about the immune system of these animals in physiological conditions. Recently, a wide number of antibodies cross reacting with buffalo antigens has been validated for use in flow cytometry (FC), allowing detailed characterization of the lymphocytic population in this species. The aim of the present study was to describe the lymphocyte subpopulations in a large number of healthy water buffaloes, providing reference intervals (RIs), and to assess whether the composition of blood lymphocyte population significantly varied with age and reproductive history. Our final aim was to lay the ground for future studies evaluating the role of host immune response in water buffaloes. One-hundred-twelve healthy buffaloes from four different herds in the South of Italy were included in the study. All animals had been vaccinated for Infectious Bovine Rhinotracheitis (IBR), Salmonellosis, Colibacillosis and Clostridiosis, and all herds were certified Brucellosis- and Tuberculosis-free. Venous blood collected into EDTA tubes was processed for FC, and the percentage of cells staining positive for the following antibodies was recorded: CD3, CD4, CD8, CD21, TCR-δ-N24, WC1-N2, WC1-N3 and WC1-N4. Absolute concentration of each lymphoid subclass was then calculated, based on automated White Blood Cell (WBC) Count. Reference Intervals were calculated according to official guidelines and are listed in the manuscript. The composition of the lymphocyte population varied with age and reproductive history, with animals <2-years-old and heifers having higher concentration of most of the subclasses. The present study provides RIs for the main lymphocytic subclasses in healthy water buffaloes, highlighting gross differences between young and old animals. Establishment of age-specific RIs is recommended in water buffaloes. The data we present may be useful as a basis for further studies concerning mechanisms of immune response toward infectious agents in water buffaloes.

Prognostic significance of peripheral blood and bone marrow infiltration in newly-diagnosed canine nodal marginal zone lymphoma

Canine nodal marginal zone lymphoma (nMZL) is infrequent and is typically diagnosed at an advanced disease stage. However, it is currently unknown whether different levels of peripheral blood (PB) and bone marrow (BM) infiltration may provide prognostic stratification in dogs with nMZL. The aims of the present prospective study were to assess the influence of PB and BM infiltration detected by flow cytometry (FC) on time to progression (TTP) and lymphoma-specific survival (LSS) in dogs with newly-diagnosed multicentric nMZL, and to establish a cut-off value of prognostic significance. Forty-five completely staged and treatment-naïf dogs with histologically-confirmed nMZL were enrolled. After staging, dogs received chemo-immunotherapy or chemotherapy. PB infiltration was significantly associated with TTP (p=0.001): dogs with PB infiltration <30% had a median TTP of 186 days, whereas dogs with PB infiltration ≥30% had a median TTP of 43 days. Additionally, vaccinated dogs had a significantly (p=0.012) longer TTP (399 days) compared with dogs receiving chemotherapy only (211 days). BM infiltration was significantly associated with LSS (p<0.001): dogs with BM infiltration <1% had a median LSS of 1403 days, those with BM infiltration 1-20% of 337 days, and those with BM infiltration ≥20% of 188 days. Normal LDH levels and the administration of chemo-immunotherapy also significantly improved LSS (560 vs 211 days, and 399 vs 211 days, respectively; p<0.001). PB and BM flow cytometric evaluation is an integral part of staging work-up in dogs with nMZL and has prognostic relevance.

A retrospective study of flow cytometric characterization of suspected extranodal lymphomas in dogs

Flow cytometry (FC) is widely applied to characterize and stage nodal lymphomas in dogs because it has a short turnaround time, requires minimally invasive sampling, and allows contemporary evaluation of neoplastic cells in the primary lesion and of blood and marrow involvement. We investigated advantages and limitations of FC in suspected extranodal lymphomas in dogs. The likelihood of obtaining a suitable FC sample was significantly lower for aspirates of extranodal lesions than for lymph node aspirates. However, we noted no differences among different extranodal lesion sites. We also describe FC results for 39 samples compatible with extranodal lymphoma. A dominant population of large cells was easily identified on morphologic FC scattergrams in many cases. Phenotypic aberrancies were frequently present, mainly in T-cell lymphomas. Lymphoma cells were distinguishable from normal residual lymphocytes in >85% of cases, facilitating the quantification of putative blood and marrow involvement by FC. Despite the high percentage of non-diagnostic samples (32 of 73, >40%), we support the inclusion of FC in the diagnostic workup of suspected extranodal lymphomas in dogs, in conjunction with histopathology. Histopathology is the gold standard for diagnosing lymphoma, provides relevant information, including tissue invasion and epitheliotropism, but has a longer turnaround time.

Flow Cytometric Characterization of S-phase Fraction and Ploidy in Lymph Node Aspirates from Dogs with Lymphoma

Canine lymphoma is a multifaceted disease encompassing numerous entities with different prognosis. Objective assessment of the proliferation rate is of importance from the pathological and clinical perspectives. Different methods have been described in the literature to assess proliferation rate, including evaluation of Ki67 expression in fresh lymph node (LN) aspirates measured by flow cytometry (FC). This test has a high accuracy in discriminating between low- and high-grade lymphomas, and provides prognostic information among high-grade B-cell lymphomas. DNA content analysis is less expensive and suitable for well-preserved samples. We describe DNA-content analysis using LN aspirates from 112 dogs with lymphoma. S-phase fraction (SPF) accurately discriminated between low- and high-grade lymphomas, with 3.15% being the best discriminating cut-off value. SPF values strongly correlated with Ki67 expression as assessed by FC. Survival analyses were restricted to 33 dogs with high-grade B-cell lymphoma receiving standardized multi-agent chemotherapy, but no significant result was obtained for SPF. We also describe a subset of aneuploid cases and their respective follow-up. We conclude that DNA content analysis may be combined with morphological examination of LN aspirates to improve the objectivity in lymphoma subtype classification in dogs. Further studies are needed to assess the possible prognostic role of SPF and ploidy status within specific lymphoma subtypes in dogs.

Canine nodal marginal zone lymphoma: Descriptive insight into the biological behaviour

Canine nodal marginal zone lymphoma (nMZL) is classified as an indolent lymphoma. Such lymphomas are typified by low mitotic rate and slow clinical progression. While the clinical behaviour of canine splenic MZL has been described, characterized by an indolent course and a good prognosis following splenectomy, there are no studies specifically describing nMZL. The aim of this study was to describe the clinical features of and outcome for canine nMZL. Dogs with histologically confirmed nMZL undergoing a complete staging work-up (including blood analysis, flow cytometry [FC] on lymph node [LN], peripheral blood and bone marrow, imaging, histology and immunohistochemistry on a surgically removed peripheral LN) were retrospectively enrolled. Treatment consisted of chemotherapy or chemo-immunotherapy. Endpoints were response rate (RR), time to progression (TTP) and lymphoma-specific survival (LSS). A total of 35 cases were enrolled. At diagnosis, all dogs showed generalized lymphadenopathy. One-third was systemically unwell. All dogs had stage V disease; one-third also had extranodal involvement. The LN population was mainly composed of medium-sized CD21+ cells with scant resident normal lymphocytes. Histology revealed diffuse LN involvement, referring to "late-stage" MZL. Median TTP and LSS were 149 and 259 days, respectively. Increased LDH activity and substage b were significantly associated with a shorter LSS. Dogs with nMZL may show generalized lymphadenopathy and an advanced disease stage. Overall, the outcome is poor, despite the "indolent" designation. The best treatment option still needs to be defined.

European Veterinary Renal Pathology Service: A Survey Over a 7-Year Period (2008-2015)

Background

The European Veterinary Renal Pathology Service (EVRPS) is the first Web‐based registry for canine renal biopsy specimens in Europe.

Hypothesis/Objectives

The aim was to verify whether differences exist between the clinical and laboratory presentation of dogs with nephropathy according to renal pathological findings, as defined by light and electron microscopy of renal biopsy specimens submitted to EVRPS.

Animals

Renal biopsy specimens of dogs were collected from the archive of the service (n = 254). Cases were included if both light and electron microscopy were available (n = 162).

Methods

Renal biopsy specimens were classified based on the morphological diagnoses. Thereafter, they were grouped into 3 disease categories, including immune‐complex‐mediated glomerulonephritis (ICGN), non‐immune‐complex‐mediated GN (non‐ICGN), and renal lesions not otherwise specified (RL‐NOS). Differences among morphological diagnoses and among disease categories were investigated for clinical and laboratory variables.

Results

Serum albumin concentration was lower in dogs with ICGN than in those with non‐ICGN (P = 0.006) or RL‐NOS (P = 0.000), and the urine protein‐to‐creatinine ratio (UPC) was significantly higher in ICGN than in the other 2 disease categories. Regarding morphological diagnoses, albumin was significantly lower in amyloidosis (AMY) and membranous (MGN), membranoproliferative (MPGN) or mixed glomerulonephritis (MixGN) than in minimal change disease, primary (FSGS I) or secondary (FSGS II) focal and segmental glomerulosclerosis and juvenile nephropathies (JN). The UPC was higher in MPGN than in FSGS I and FSGS II.

Conclusions and clinical importance

Dogs with ICGN, in particular MPGN, had higher protein loss than those with non‐ICGN or RL‐NOS, leading to more severe hypoalbuminemia. Clinical and laboratory differentiation among dogs with the different morphological diagnoses and among dogs with different disease categories was difficult due to overlapping results.

Flow cytometry for feline lymphoma: a retrospective study regarding pre-analytical factors possibly affecting the quality of samples

Objectives

Flow cytometry (FC) is becoming increasingly popular among veterinary oncologists for the diagnosis of lymphoma or leukaemia. It is accurate, fast and minimally invasive. Several studies of FC have been carried out in canine oncology and applied with great results, whereas there is limited knowledge and use of this technique in feline patients. This is mainly owing to the high prevalence of intra-abdominal lymphomas in this species and the difficulty associated with the diagnostic procedures needed to collect the sample. The purpose of the present study is to investigate whether any pre-analytical factor might affect the quality of suspected feline lymphoma samples for FC analysis.

Methods

Ninety-seven consecutive samples of suspected feline lymphoma were retrospectively selected from the authors’ institution’s FC database. The referring veterinarians were contacted and interviewed about several different variables, including signalment, appearance of the lesion, features of the sampling procedure and the experience of veterinarians performing the sampling. Statistical analyses were performed to assess the possible influence of these variables on the cellularity of the samples and the likelihood of it being finally processed for FC.

Results

Sample cellularity is a major factor in the likelihood of the sample being processed. Moreover, sample cellularity was significantly influenced by the needle size, with 21 G needles providing the highest cellularity. Notably, the sample cellularity and the likelihood of being processed did not vary between peripheral and intra-abdominal lesions. Approximately half of the cats required pharmacological restraint. Side effects were reported in one case only (transient swelling after peripheral lymph node sampling).

Conclusions and relevance

FC can be safely applied to cases of suspected feline lymphomas, including intra-abdominal lesions. A 21 G needle should be preferred for sampling. This study provides the basis for the increased use of this minimally invasive, fast and cost-effective technique in feline medicine.

Strategies to exclude subjects who conceal and fabricate information when enrolling in clinical trials

Clinical trials within the US face an increasing challenge with the recruitment of quality candidates. One readily available group of subjects that have high rates of participation in clinical research are subjects who enroll in multiple trials for the purpose of generating income through study payments. Aside from issues of safety and generalizability, evidence suggests that these subjects employ methods of deception to qualify for the strict entrance criteria of some studies, including concealing information and fabricating information. Including these subjects in research poses a significant risk to the integrity of data quality and study designs. Strategies to limit enrollment of subjects whose motivation is generating income have not been systematically addressed in the literature. The present paper is intended to provide investigators with a range of strategies for developing and implementing a study protocol with protections to minimize the enrollment of subjects whose primary motivation for enrolling is to generate income. This multifaceted approach includes recommendations for advertising strategies, payment strategies, telephone screening strategies, and baseline screening strategies. The approach also includes recommendations for attending to inconsistent study data and subject motivation. Implementing these strategies may be more or less important depending upon the vulnerability of the study design to subject deception. Although these strategies may help researchers exclude subjects with a higher rate of deceptive practices, widespread adoption of subject registries would go a long way to decrease the chances of subjects enrolling in multiple studies or more than once in the same study.

DNA methylation and targeted sequencing of methyltransferases family genes in canine acute myeloid leukaemia, modelling human myeloid leukaemia

Tumours shows aberrant DNA methylation patterns, being hypermethylated or hypomethylated compared with normal tissues. In human acute myeloid leukaemia (hAML) mutations in DNA methyltransferase (DNMT3A) are associated to a more aggressive tumour behaviour. As AML is lethal in dogs, we defined global DNA methylation content, and screened the C-terminal domain of DNMT3 family of genes for sequence variants in 39 canine acute myeloid leukaemia (cAML) cases. A heterogeneous pattern of DNA methylation was found among cAML samples, with subsets of cases being hypermethylated or hypomethylated compared with healthy controls; four recurrent single nucleotide variations (SNVs) were found in DNMT3L gene. Although SNVs were not directly correlated to whole genome DNA methylation levels, all hypomethylated cAML cases were homozygous for the deleterious mutation at p.Arg222Trp. This study contributes to understand genetic modifications of cAML, leading up to studies that will elucidate the role of methylome alterations in the pathogenesis of AML in dogs.

Identification of a suitable internal control for fluorescence analysis on canine peripheral blood samples

Reliable detection of fluorescence intensity (FI) by flow cytometry (FC) is fundamental. FI depends on instrument settings and sample processing procedures: thus, measurements should be done using internal controls with known FI. Commercially available beads-based standards are expensive, thus reducing their usability in the veterinary practice. Cell subsets with stable mean FI (MFI) within the population have been proposed as acceptable surrogates in human medicine. In veterinary medicine, no data exist about stability of antigen expression among different subjects or upon sample storage. The aim of the present study was to evaluate MFI variability of main lymphocytes antigens among the lymphoid cells within each subject, among different subjects, and upon 24-h storage, in order to identify the antigen most suitable as stable internal control in MFI analyses. Peripheral blood samples from 18 healthy dogs were analysed by FC within 3h from sampling to assess the expression of CD3, CD5, CD4, CD8, CD21 and cyCD79b using conjugated monoclonal antibodies. Analyses were restricted to the lymphoid population. Fluorescent microbeads were added to each tube, and antigen MFI was calculated as Relative Fluorescence Intensity RFI (CD/beads). Fluorescence histogram CV (fhCV) for each CD was regarded as an index of the variability of expression among lymphocytes within each subject (cell-to-cell variability); whereas the CV of RFI was regarded as an index of inter-subjects variability (dog-to-dog variability). In 11 cases, FC analyses were repeated after 24h storage at 4°C and RFI and CVs of fresh and stored samples were compared to assess variability linked to storage. CD4 was identified as the best antigen to be used as an internal control for MFI analyses in canine peripheral blood samples because of low cell-to-cell and dog-to-dog variability, and optimal stability upon 24-h storage. Blood samples from a second group of 21 healthy dogs were labelled only with CD4, in order to assess the influence of breed, sex and age on the expression of CD4 in a larger case series. Based on univariate GLMs, none of these variables influenced CD4 RFI. Normalizing fluorescence data using lymphoid CD4 MFI as a reference would improve the comparison of results obtained by different laboratories, patients or times in diagnostic and research analyses of FI. Further studies are needed to confirm our results with different FC approaches.

Analytical and diagnostic validation of a flow cytometric strategy to quantify blood and marrow infiltration in dogs with large B-cell lymphoma

BACKGROUND

Lymph node (LN), peripheral blood (PB), and bone marrow (BM) samples are commonly analyzed by flow cytometry (FC) for the immunophenotyping and staging of canine lymphomas. A prognostic value for FC BM infiltration in dogs with large B-cell lymphoma (LBCL) was demonstrated. Aim of this study was to define the analytical performances of this technique, and to establish a cutoff suitable to safely discriminate between infiltrated and noninfiltrated PB and BM samples.

METHODS

Large B-cells were added to control PB and BM samples, to achieve twelve different large B-cells concentrations, ranging from 0 to 50%. The percentage of large B-cells was recorded for each dilution, using a BD Accuri C6 FC. Accuracy was evaluated by Passing-Bablok regression analysis. Intra-assay precision was assessed at 0%, 1, 3, and 10% dilutions evaluating the CVs of 10 repeated acquisitions. ROC curves were drawn to identify the cutoffs most suitable to discriminate between 25 infiltrated (PARR-positive) and 25 noninfiltrated (PARR-negative) PB and BM samples, respectively.

RESULTS

Optimal analytical accuracy and precision were achieved. Almost all CVs were <10%. Negative controls had up to 0.5% large B-cells, with 50 and 22% CV in PB and BM samples, respectively, 0.56 and 2.45% cutoffs were selected based on the ROC curves for PB and BM samples, respectively.

CONCLUSIONS

Quantification of large B-cells in PB and BM samples by FC is reliable and analytical performances met the acceptance criteria. Assessment of performances of different instruments and protocols is warranted. © 2016 International Clinical Cytometry Society.

Prognostic significance of Ki67 evaluated by flow cytometry in dogs with high-grade B-cell lymphoma

Ki67 can discriminate between high- and low-grade canine lymphomas, but its prognostic role in specific subtypes of the neoplasm is unknown. We assessed the prognostic significance of Ki67% (percentage of Ki67-positive cells), evaluated by flow cytometry, in 40 dogs with high-grade B-cell lymphoma, treated with a modified Wisconsin-Madison protocol (UW-25). The following variables were investigated for association with lymphoma specific survival (LSS) and relapse free interval (RFI): Ki67%, breed, sex, age, stage, substage, complete remission (CR). By multivariate analysis, Ki67% (P = 0.009) and achievement of CR (P = 0.001) were independent prognostic factors for LSS. Dogs with intermediate Ki67% (20.1-40%) presented longer LSS and RFI (median = 866 and 428 days, respectively) than dogs with low (median = 42 days, P < 0.001; median = 159 days, P = 0.014) or high (median = 173 days, P = 0.038; median = 100 days, P = 0.126) values. Determination of Ki67 is a prognostic tool that improves the clinical usefulness of flow cytometric analysis in canine high-grade B-cell lymphoma.

Lymphocyte subpopulations and Treg cells in dogs with atopic dermatitis receiving ciclosporin therapy: a prospective study

BACKGROUND

Canine atopic dermatitis (CAD) is a chronic dermatological disease partly due to dysregulation of the immune system. Inappropriate activation of CD4(+) lymphocytes could favour and promote the allergic response. An inadequate activation system of regulatory T cells (Tregs) is suspected to be a key immunological feature of the allergic response in atopic dogs.

HYPOTHESIS/OBJECTIVES

To evaluate the difference in the CD4/CD8 lymphocyte ratio and the percentage of Tregs in healthy dogs, in a breed predisposed to CAD, and in dogs affected by CAD before and during therapy with ciclosporin (CsA). Additionally to assess the improvement in pruritus and skin lesions during therapy with CsA, and to compare this with CD4/CD8/Treg values.

ANIMALS

Ten atopic dogs of different breed, sex and age, ten healthy dogs and ten English bulldogs were included.

METHODS

Peripheral blood from all dogs was tested using flow cytometry to assess the CD4/CD8 ratio and percentage of Tregs. For atopic dogs, sampling was repeated after 30 and 90 days of therapy with CsA.

RESULTS

The CD4/CD8 ratio was not significantly different between the three groups. The Treg percentage was higher, but not statistically significant, in atopic dogs compared with controls. Therapy with CsA led to clinical improvement; it was not associated with statistically significant differences in haematological variables.

CONCLUSION AND CLINICAL IMPORTANCE

This study suggests that Tregs may be involved in the pathogenesis of CAD and that ciclosporin therapy does not affect the circulating lymphocyte subpopulations.