Cytokine storm syndrome after anti-thymoglobulin infusion in a cynomolgus monkey with systemic lymphadenopathy caused by follicular hyperplasia: A case report

Nonhuman primates are widely used in transplantation research as preclinical xeno- or allo-transplantation models. Rabbit anti-thymoglobulin (ATG) is often used for T-cell depletion as an immunosuppressant. T-cell depletion can cause a secondary cytokine storm syndrome that can be minimized/prevented by a prophylactic administration of systemic corticosteroids and antihistamines. We report a case of death due to CSS in a cynomolgus monkey with follicular hyperplasia-induced systemic lymphadenopathy after ATG administration. A 6-year-old female cynomolgus monkey was rendered diabetic and then transplanted with a genetically modified porcine pancreatic islets (PPI) (50 000 IEQ/kg) through the portal vein 22 days later without immunosuppressant. Because graft function was not comparable, we planned re-transplantation of PPI. For re-transplantation of the PPI, we performed an intravenous (IV) ATG infusion for inductive immunosuppression. The monkey died 3 h and 30 min after ATG administration despite cardiopulmonary resuscitation. Systemic lymphadenopathy was observed on submandibular, axillary, inguinal, foregut, colic, and hilar lymph nodes, and splenomegaly was also observed on necropsy. Histopathologic examination of the lymph node revealed follicular hyperplasia. The IL-6 level was higher after ATG infusion compared to before ATG infusion (before vs. after ATG infusion; 14.9 vs. >5000 pg/mL). The death of the cynomolgus monkey was caused by severe CSS because of apoptosis of B cells in the systemic lymph nodes caused by the ATG administration. A thorough physical examination of palpable lymph nodes and pre-ATG sonographic or computed tomographic screening could have identified lymphadenopathy, potentially preventing its infusion and reducing mortality risk.

Retrospective study evaluating the efficacy of stereotactic body radiation therapy for the treatment of confirmed or suspected primary pulmonary carcinomas in dogs

Canine primary pulmonary carcinomas (PCCs) are commonly treated with surgery with overall median survival times (MST) around a year; however, due to extent of disease, prognosis, or client preference, alternative treatments have been considered. Stereotactic body radiation therapy (SBRT) has been utilized in human cancer patients for local control of lung tumours as a surgical alternative. Twenty-one PCCs in 19 dogs that received SBRT for local control were retrospectively evaluated. Dogs were staged according to the canine lung carcinoma stage classification (CLCSC) system with three as Stage 1, five as Stage 2, three as Stage 3, and eight as Stage 4. Overall MST was 343 days with 38% of patients alive at 1 year. Stage did not significantly impact survival time (p = .72). Five (26%) dogs had lymphadenopathy and MST was not significantly different from dogs without lymphadenopathy (343 vs. 353 days; p = .54). Five out of 18 evaluable dogs (28%) experienced acute lung VRTOG effects and 2 of 12 dogs (17%) experienced late lung VRTOG effects. Median lung dose, V5, V20, and D30 to the lung did not correlate significantly with the development of adverse radiation events. Twelve dogs had follow-up imaging and the best response included a complete response (17%), partial response (42%), and stable disease (42%). Progressive disease was noted in seven dogs a median of 229 days after SBRT. SBRT was documented to be a safe and effective alternative to surgery and may have survival advantages for Stage 3 or 4 dogs according to the CLCSC.

Temporal tracheobronchial lymphadenopathy resolution is affected by initial severity and poorly correlated to serologic antibody testing in dogs with pulmonary coccidioidomycosis

OBJECTIVE

To determine associations between antibody serologic tests and tracheobronchial lymphadenopathy (TBL) in dogs with pulmonary coccidioidomycosis and identify variables associated with time to resolution of TBL.

ANIMALS

32 client owned dogs with newly diagnosed pulmonary coccidioidomycosis from October 2020 to February 2021.

METHODS

Prospective cohort study. Thoracic radiographs and anti-Coccidioides spp antibody serology were performed at baseline and once every 3 months until remission or for a maximum of 12 months. Radiographic tracheobronchial lymph node height, length, and area were measured and recorded as ratios via comparison with the length of the T4 vertebral body (LT4) and length of the manubrium. Severity of TBL was also subjectively categorized as mild, moderate, or severe.

RESULTS

Tracheobronchial lymphadenopathy was identified in 81% (26/32; 95% CI, 64% to 93%) of dogs. There was no relevant association between TBL presence or severity and antibody serology results. Tracheobronchial lymphadenopathy resolved in 72% (n = 18) of dogs at the 3-month evaluation. The median time to resolution of TBL after initiation of fluconazole was 96 days (range, 72 to 386 days). Univariate analysis identified increasing TBL severity (hazard ratio, 0.40; 95% CI, 0.19 to 0.84; P = .02) and length:LT4 ratio (hazard ratio, 0.41; 95% CI, 0.20 to 0.82; P = .01) as variables associated with reduced probability of resolution of TBL.

CLINICAL RELEVANCE

Antibody serologic test results are not clinically useful to predict TBL presence or severity in dogs with pulmonary coccidioidomycosis, and larger tracheobronchial lymph nodes are more likely to take longer to resolve. Resolution of TBL occurs in most dogs within 3 to 6 months after fluconazole administration.

Significant increase in MIC-A and MIC-B and soluble MIC-A and MIC-B in canine lymphomas

Non-Hodkin's lymphoma (NHL) is the most frequent hematologic malignancy in humans and dogs. NKG2D is one of the most critical receptors on NK cells, recognizing their natural ligands on malignant cells such as A and B major histocompatibility complex-related proteins (MIC-A and MIC-B). Soluble molecules (sMIC-A and sMIC-B) can interfere with immune synapsis between NK cells and tumor cells, impeding NK cytotoxicity. The main objectives of this study were to analyze, in dogs with diffuse large B cell lymphoma, NK cell lymphoma, and reactive lymphadenopathies, the role of NK cells, their activating receptors NKG2D and NKp46, and their ligands MIC-A and MIC-B, as well as soluble molecules sMIC-A and sMIC-B. Thirty-six dogs with a possible diagnosis of NHL and eight healthy dogs were studied. NHL was diagnosed in 28 (78 %) dogs; in the other 8 (22 %), reactive lymphadenopathies were present. Most of the lymphomas corresponded to B cell NHL (82 %). The most predominant subtype was diffuse large B cell lymphoma (21, 71.5 %), followed by five cases (18 %) that were Non-B Non-T lymphomas (presumably NK cell lymphomas) and other B cell lymphomas (3, 10.5%). There were no cases of T cell NHL. MIC-A was positive in 7 of 27 (26 %) cases of NHL, and MIC-B in 20 of 27 (74 %) NHL. In non-malignant lymphadenopathies, three (37.5 %) dogs were positive for MIC-A, and five (62.5 %) expressed MIC-B. Dogs with lymphoma had higher numbers of NK cells than eight healthy dogs. In 15 dogs (12 cases with NHL and three cases with reactive adenopathies) and eight controls, there were no differences in the number of NK cells expressing NKP46 and NKG2D. NHL dogs had higher values of sMIC-A and sMIC-B. B-cell and NK cell lymphomas correspond to 86 % and 14 % of all canine lymphomas. MIC-A, MIC-B, and sMIC-A and sMIC-B were increased in canine lymphomas.

Histopathological and molecular methods as complementary diagnostic in case of lymphadenopathies suggestive of bovine tuberculosis

Bovine tuberculosis (TB) is a chronically evolving zoonotic infectious disease caused by Mycobacterium bovis. Anatomopathological examination during post mortem inspection in bovines is the main resource engaged in sanitary slaughter; however, it is very troublesome since many granulomatous inflammatory processes have similar morphological characteristics. Thus, this study aims to use complementary diagnosis methods (histopathological and polymerase chain reaction - PCR assays) to confirm the macroscopic assessment of lymphadenopathies indicative of tuberculosis in bovines slaughtered in a refrigerated slaughterhouse in Tailândia city, PA, Brazil. Fifty‑one samples were collected from lesions indicative of tuberculosis in pre‑scapular and pre‑pectoral lymph nodes (or different lymphadenitis) in condemned carcasses. Histological processing employed routine techniques carried out at the Laboratory of Animal Pathology of the Federal Rural University of the Amazon, while the PCR assay was performed at the Bacteriology Laboratory of the Evandro Chagas Institute. Results showed that 1.96% of the histopathology samples corresponded to inflammatory processes typical of TB and that, in PCR, 4.25% of the samples had the amplification profile of the M. bovis species. These results indicate the importance of adding complementary methods to assist the sanitary inspection line and make inspection more efficient in its decisions.

Preliminary study of CT features of intermediate- and high-grade alimentary lymphoma and adenocarcinoma in cats

CASE SERIES SUMMARY

The ultrasonographic findings of many feline intestinal tumours are similar. This study evaluated the CT features of intermediate- and high-grade alimentary lymphoma and adenocarcinoma in cats. CT was performed on six cats with adenocarcinoma and 14 cats with lymphoma. Comparisons between tumour types were conducted, focusing on CT features, including obstruction (present or absent), growth patterns of lesions (symmetry or asymmetry), layering enhancement (present or absent), location of the lesion, number of lesions (solitary or multiple), lymphadenopathy (present or absent), location of lymphadenopathy, pulmonary metastasis (present or absent) and maximum thickness (mm) of the lesion. The cats with adenocarcinoma (n = 5/6 [83%]) experienced intestinal obstruction significantly more often than cats with lymphoma (n = 0/14 [0%]; P = 0.0004). Layering enhancement was observed significantly more often in cats with adenocarcinoma (n = 6/6 [100%]) than in cats with lymphoma (n = 1/14 [7%]; P = 0.0002). Lymphadenopathy was detected significantly more often in cats with lymphoma (n = 14/14 [100%]) than in cats with adenocarcinoma (n = 2/6 [33%]) (P = 0.003). In cats with lymphoma, the intestine (12.1 ± 3.9 mm) was significantly thicker than that in cats with adenocarcinoma (6.4 ± 2.3 mm; P = 0.005).

RELEVANCE AND NOVEL INFORMATION

To the best of our knowledge, no reports have described the characteristics of feline intestinal tumours using CT. Layering enhancement was observed in cats with intestinal adenocarcinomas. No layering enhancement was observed in alimentary lymphoma in cats, but enlarged regional nodes were noted. Lesions with lymphoma were thicker than those with adenocarcinoma. These findings may help differentiate between adenocarcinomas and lymphomas.

Retrospective study of canine peripheral lymphadenopathy in a Mediterranean region: 130 cases

Lymphadenopathy is a common clinical concern in dogs. Causes of lymphadenopathy include neoplasia, infection, and immune-mediated diseases. Seasonal infectious diseases should be considered as a potential cause of lymphadenopathy in endemic regions, such as the Mediterranean region. Therefore, the purpose of this study was to evaluate the causes of peripheral lymph node enlargement in dogs in a Mediterranean region (north‑eastern Spain). In addition, we aimed to assess the relationship between peripheral lymphadenopathy and other clinical data. Medical records of dogs admitted to two referral hospitals in Barcelona (Spain) with peripheral lymphadenopathy and cytological evaluation of lymph nodes, during a 4-year period (2015 to 2019) were included. One hundred and thirty dogs met the inclusion criteria. The most common final clinical diagnoses were lymphoproliferative neoplasia (36%) and dermatological disease (18.4%), followed by vector borne infectious disease (VBID; 16.5%). In the VBID group, 19 dogs were positive for Leishmania infantum and two dogs were positive for heartworm antigen. The presence of lymphadenopathy as the only clinical sign, generalized peripheral lymphadenopathy and internal lymphadenopathy was more frequent in dogs with lymphoma. The patients with metastatic neoplasms had significantly more localized lymphadenopathy compared to the other diagnosis groups. Twenty percent of the dogs had fever and this was more frequent in the immunemediated disease group. Our findings suggest that lymphoma is the most likely cause of lymphadenopathy in dogs. Clinicians should consider lymphoproliferative neoplasia in dogs with general peripheral lymphadenopathy concurrent with internal (abdominal or thoracic) lymphadenopathy and without other clinical signs. A higher incidence of immune-mediated disease was found in the population of febrile dogs included in this study.

Evaluation of radiographs for the detection of sublumbar lymphadenopathy in dogs

The purpose of this study was to evaluate radiographs for the detection of sublumbar lymph node (SLN) enlargement. Ultrasound was used to determine SLN size. Twenty-two dogs with anal gland adenocarcinoma or lymphoma were prospectively included, with 16/22 having SLN enlargement on ultrasound. Twenty-one dogs without enlargement were retrospectively included as controls. Three blinded observers evaluated 43 right lateral abdominal radiographs for the presence of SLN enlargement. Sensitivity and specificity of radiographs for the detection of SLN enlargement were 81%/70%, 94%/81%, and 75%/100% for a general practitioner, imaging resident, and radiologist, respectively. Ventral displacement of the colon, a soft tissue opacity in the caudal retroperitoneal space and loss of conspicuity of the ventral margin of the iliopsoas muscle were radiographic findings significantly associated with identification (P-values < 0.05). Markedly enlarged SLNs (> 21.5 mm) were consistently detected radiographically by observers with specialist imaging training. Key clinical message: Radiographic visualization should raise suspicion of neoplastic infiltration of SLN but lack of visualization does not exclude mild to moderate enlargement. Additional imaging such as ultrasound or computed tomography remains important to confirm or exclude sublumbar lymphadenopathy.

Contrast-enhanced computed tomography findings of canine primary renal tumors including renal cell carcinoma, lymphoma, and hemangiosarcoma

In veterinary medicine, abdominal ultrasonography is used to rank the differential diagnosis of renal lesions. However, a conventional sonographic examination may show nonspecific findings. The purpose of this study was to assess the computed tomography (CT) findings of canine renal tumors, including renal cell carcinoma (RCC), lymphoma, and hemangiosarcoma (HSA). In this retrospective study, the following CT parameters were recorded for each dog: 1) extent of renal involvement of tumors, 2) enhancement pattern, 3) number of renal tumors, 4) renal tumor vessel enhancement in the corticomedullary phase, 5) presence of lymphadenopathy and lung metastasis, and 6) attenuation values of the renal tumors on the pre- and post-contrast corticomedullary, nephrographic, and excretory phase images. Fifteen dogs met the inclusion criteria, of which nine had RCCs, four had lymphomas, and two had HSAs. RCCs tended to show heterogeneous enhancement and unilateral renal involvement, and vessel enhancement was detected in the corticomedullary phase in dogs with RCC. Conversely, renal lymphomas showed homogeneous enhancement, bilateral renal involvement, and multiple masses; in these dogs, no vessel enhancement was detected in the corticomedullary phase, and the incidence of lymphadenopathy was low. However, in dogs with lymphadenopathy, the renal lymphoma was associated with regionally severe lymphadenopathy. Finally, renal HSAs tended to show heterogeneous enhancement with a non-enhanced area and unilateral renal involvement; in these dogs, vessel enhancement was detected in the nephrographic phase, with the enhancement expanding around the vessel. These findings had no significant differences. Further studies with a larger sample size are required to examine the association between CT and histopathological findings.

Presumptive Spontaneous Lysosomal Storage-Like Disease in a Crl:CD1(ICR) Mouse

A clinically unremarkable 4.5-mo-old female Crl:CD1(ICR) VAF/Elite mouse was euthanized for scheduled sentinel processing. Gross necropsy findings included significant hepatosplenomegaly and visceral lymphadenomegaly, resulting in a preliminary gross diagnosis of lymphoma. Histology revealed florid accumulations of large, 'foamy' macrophages present in the bone marrow, small intestines, and viscera including liver, spleen, lymph nodes, thymus, uterus, and ovaries. The cytoplasm of these cells was abundant, stained pale blue with Wright-Giemsa and was periodic acid-Schiff positive. Given these characteristic gross and histologic findings, a spontaneous lysosomal storage-like disease was diagnosed in this mouse. Cholesterol ester storage disease is likely, because of the visceral involvement with sparing of the CNS, but could not be diagnosed definitively. To our knowledge, this report is the first to describe a case of spontaneous lysosomal storage disease in an outbred mouse of the CD1(ICR) background.