Serum levels of innate immunity cytokines are elevated in dogs with metaphyseal osteopathy (hypertrophic osteodytrophy) during active disease and remission

Clinical findings, treatment and outcome of trapped neutrophil syndrome in Border Collies: 12 cases (2011-2022)

OBJECTIVES

This study aimed to evaluate clinical signs, diagnostic findings, treatment administered and short- (survival to 28 days) and long-term prognosis (survival >6 months) in dogs diagnosed with trapped neutrophil syndrome.

MATERIALS AND METHODS

Medical records of 12 dogs (10 Border Collies and two Border Collie Crossbreeds) homozygous for VPS13B gene mutation causing trapped neutrophil syndrome from seven veterinary institutions between January 2011 and June 2022 were evaluated retrospectively.

RESULTS

The most common clinical signs at the time of diagnosis were pyrexia, abnormal gait and gastrointestinal signs. Concurrent metaphyseal osteopathy and immune-mediated polyarthritis were common. Seven dogs had a segmented neutrophil count below, four dogs within and one dog above the analyser reference interval at presentation. Two dogs had a septic source identified and both were additionally identified to be homozygous mutant positive on DNA testing by polymerase chain reaction (PCR) for canine cyclic neutropenia. All dogs received at least one antimicrobial agent and 10 dogs received treatment with prednisone or prednisolone (median starting dose 1 mg/kg/day; range 0.5 to 2.5 mg/kg/day). Nine dogs were alive at 28 days and six dogs were alive at 6 months post-diagnosis.

CLINICAL SIGNIFICANCE

Trapped neutrophil syndrome should be suspected in young Border Collies with pyrexia, lameness and gastrointestinal signs. Neutropenia may not always be present and long-term survival is possible. A septic focus was not commonly identified in our population; however, our results suggest that if identified, testing for concurrent canine cyclic neutropenia should be considered.

Refractory shock, hypercoagulability, and multiorgan thrombosis associated with hypertrophic osteodystrophy in a dog

OBJECTIVE

To describe the clinical findings and case progression in a dog presenting with severe systemic inflammatory response, refractory shock, progressive metabolic acidosis, and respiratory failure that was ultimately diagnosed with hypertrophic osteodystrophy (HOD).

CASE SUMMARY

A 4-month-old male intact Mastiff presented with a 24-hour history of lethargy and generalized ostealgia. On examination, the dog was recumbent, febrile, and tachycardic with pain on palpation of the abdomen, right femur, and mandible. Appendicular joint radiographs showed changes consistent with osteochondrosis and ulnar-retained cartilaginous cores, with no overt evidence of HOD. Initial treatment included IV fluid therapy, multimodal analgesia, and broad-spectrum antimicrobials. Vasopressor therapy was initiated following hemodynamic decompensation. Synovial fluid cytological analysis and culture revealed nonseptic suppurative inflammation and no bacterial growth, respectively. Blood and urine cultures also yielded no growth. Viscoelastic testing was consistent with hypercoagulability. The dog initially had a metabolic acidosis with appropriate respiratory compensation that progressed to a mixed metabolic and respiratory acidosis despite aggressive therapies that included antimicrobials, vasopressors, positive inotropes, and corticosteroids. Humane euthanasia was elected approximately 32 hours after admission. Necropsy yielded a diagnosis of HOD.

NEW OR UNIQUE INFORMATION PROVIDED

This is the first report detailing the occurrence of refractory shock and hypercoagulability associated with HOD in a dog without evidence of another identified comorbidity. HOD should be considered in any young, large-breed dog with generalized ostealgia and signs of systemic illness, even in the absence of classic radiographic abnormalities. Further investigation of coagulation status in dogs with HOD and a secondary systemic inflammatory response is warranted.

Presenting signs and clinical outcome in dogs with metaphyseal osteopathy: 39 cases (2009-2018)

OBJECTIVE

To describe the presenting signs, concurrent conditions, treatment and outcome of dogs with metaphyseal osteopathy.

MATERIALS AND METHODS

Multi-centre retrospective review of medical records from January 2009 to September 2018 at four referral centres to identify dogs with a radiographic diagnosis of metaphyseal osteopathy.

RESULTS

Thirty-nine dogs were identified. The median age at onset was 14 weeks old (range, 8 to 32 weeks old). There was a higher proportion of male dogs (29 of 39 male entire, nine of 39 female entire, one of 39 female neutered and no male neutered dogs). Where information was available, median time from the most recent vaccination was 20 days (range, 2 to 144 days). The most commonly recorded clinical signs were pyrexia (34 of 39), lethargy (32 of 39), pain (30 of 39), and being non-ambulatory (17 of 39). Thirty-five dogs required hospitalisation for analgesia and supportive care, 19 of 39 were discharged on prednisolone (median dose 2.0 mg/kg/day; range, 0.9 to 2.6 mg/kg/day), 18 of 39 were discharged on non-steroidal anti-inflammatories, two of 39 did not receive NSAIDs or prednisolone at any time point. The median duration of hospitalisation for those admitted was 5 days (range, 1 to 21 days). Where follow-up was available, relapse occurred in eight of 25 cases before reaching skeletal maturity. At the time of metaphyseal osteopathy diagnosis, five of 39 cases had concurrent conditions. Where follow-up was available, four of 25 developed future immune-mediated conditions.

CLINICAL SIGNIFICANCE

Metaphyseal osteopathy should be considered in non-ambulatory painful young dogs. Some dogs developed future immune-mediated conditions, which may support the hypothesis that metaphyseal osteopathy is an autoinflammatory bone disorder. Further studies with a larger cohort are required to determine the clinical significance of this.

Hypertrophic osteodystrophy in dogs: diagnosis and treatment

Hypertrophic osteodystrophy is an uncommon orthopaedic disease that affects young, growing dogs. Aetiology is currently unknown; however, several unproven etiologies have been theorised in the literature including canine distemper virus, previous vaccination, hereditary causes and auto-immune disorders. Affected animals often present with varying degrees of lameness, lethargy, pyrexia and/or distal metaphyseal swelling of affected limbs. An index of suspicion is based on clinical signs. Confirmation is obtained with radiographs of the affected limb(s) by the presence of a "double physis," or a radiolucent line that is parallel to the physis. Treatment varies depending on degree affected, but generally consists of anti-inflammatory steroids, pain medications, gastrointestinal support, nutritional management and appropriate supportive care. Critically affected patients require intensive monitoring and more aggressive supportive care for prevention of life-threatening sequalae. Prognosis is very favourable with mildly and moderately affected patients, but good to guarded in severely affected patients.

Juvenile Disease Processes Affecting the Forelimb in Canines

Several juvenile diseases affect the canine forelimb. The most common are hypertrophic osteodystrophy, panosteitis, and retained cartilaginous core. Panosteitis and hypertrophic osteodystrophy tend to be self-limiting, with a good long-term prognosis, although severe cases can develop. These diseases may recur during growth. Severe cases of hypertrophic osteodystrophy can lead to angular limb deformities and may even be fatal. Retained cartilaginous cores can be benign with no evidence of clinical signs and be found incidentally on radiographs. However, if they disrupt the distal ulnar physis, angular limb deformities may persist requiring surgical intervention with a corrective osteotomy.

Majeed Syndrome: A Review of the Clinical, Genetic and Immunologic Features

Majeed syndrome is a multi-system inflammatory disorder affecting humans that presents with chronic multifocal osteomyelitis, congenital dyserythropoietic anemia, with or without a neutrophilic dermatosis. The disease is an autosomal recessive disorder caused by mutations in LPIN2, the gene encoding the phosphatidic acid phosphatase LIPIN2. It is exceedingly rare. There are only 24 individuals from 10 families with genetically confirmed Majeed syndrome reported in the literature. The early descriptions of Majeed syndrome reported severely affected children with recurrent fevers, severe multifocal osteomyelitis, failure to thrive, and marked elevations of blood inflammatory markers. As more affected families have been identified, it has become clear that there is significant phenotypic variability. Data supports that disruption of the phosphatidic acid phosphatase activity in LIPIN2 results in immune dysregulation due to aberrant activation of the NLRP3 inflammasome and overproduction of proinflammatory cytokines including IL-1β, however, these findings did not explain the bone phenotype. Recent studies demonstrate that LPIN2 deficiency drives pro-inflammatory M2-macrophages and enhances osteoclastogenesis which suggest a critical role of lipin-2 in controlling homeostasis at the growth plate in an inflammasome-independent manner. While there are no approved medications for Majeed syndrome, pharmacologic blockade of the interleukin-1 pathway has been associated with rapid clinical improvement.

A Pilot Study on the Safety of a Novel Antioxidant Nanoparticle Delivery System and Its Indirect Effects on Cytokine Levels in Four Dogs

Acute spinal cord injury consists of a primary, traumatic event followed by a cascade of secondary events resulting in ongoing cell damage and death. There is great interest in prevention of these secondary effects to reduce permanent long-term neurologic deficits. One such target includes reactive oxygen species released following injury, which can be enzymatically converted into less harmful molecules by superoxide dismutase and catalase. Canine intervertebral disc herniation has been suggested as a naturally occurring model for acute spinal cord injury and its secondary effects in people. The aims of this study were to test the safety of a novel antioxidant delivery system in four healthy dogs and to indirectly test effect of delivery via cytokine measurement. All dogs experienced adverse events to some degree, with two experiencing adverse events considered to be severe. The clinical signs, including combinations of bradycardia, hypotension, hypersalivation, pale gums, and involuntary urination, were consistent with complement activation-related pseudoallergy (CARPA). CARPA is a well-known phenomenon that has been reported to occur with nanoparticle-based drug delivery, among other documented causes. Two dogs also had mild to moderate changes in their blood cell count and chemistry, including elevated alanine transferase, and thrombocytopenia, which both returned to normal by day 7 post-administration. Cytokine levels trended downwards over the first 3 days, but many were elevated at measurement on day 7. Intradermal testing suggested catalase as a potential cause for reactions. No long-term clinical signs were observed, and necropsy results revealed no concerning pathology. Additional evaluation of this product, including further characterization of reactions to catalase containing components, dose-escalation, and desensitization should be performed before evaluation in clinically affected dogs.

Cutaneous wound healing: canine allogeneic ASC therapy

Background

Wound healing is a complex biological process comprised of a series of sequential events aiming to repair injured tissue. Adult mesenchymal stem cells (MSCs) have been used in cellular therapy in preclinical animal studies; a promising source of MSCs is adipose tissue (AT). In this paper, we evaluated the clinical value and safety of the application of cultured allogenic MSCs from AT for acute and chronic skin wound healing in a canine model.

Methods

Twenty-four dogs of different breeds between 1 and 10 years of age with acute and chronic wounds were studied. Morphology of the wounded skin was monitored for changes over time via serial photographs and histopathological studies.

Results

The percentage of the wounds that exhibited contraction and re-epithelialization were significantly different between wounds treated with adipose mesenchymal stem cells (ASCs) and control wounds; this effect was observed in both acute and chronic conditions. At 90 days, re-epithelization of acute and chronic wounds reached more than 97%. Histopathological study revealed a reduction in inflammatory infiltrate and the presence of multiple hair follicles on day 7 after treatment with ASCs, promoting epidermal and dermal regeneration. To guarantee the safety of our treatment, we determined the serum levels of cytokine markers in our patients. ASC treatment upregulated granulocyte-macrophage colony stimulating factor (GM-CSF) at the gene level, which may contribute to the recruitment of cells that participate in skin repair to the site of injury.

Conclusions

The development of an allogenic ASC therapy to improve wound healing in a canine model could have a clinical impact in human treatment.

Interleukin-1β promotes interleulin-6 expression via ERK1/2 signaling pathway in canine dermal fibroblasts

Interleukin-6 (IL-6) is a pleiotropic cytokine involved in the regulation of the immune response and inflammation. In this study, we investigated effect of the proinflammatory cytokine interleukin-1β (IL-1β) on IL-6 expression in canine dermal fibroblasts. IL-1β induced IL-6 mRNA expression and protein release in a time- and dose-dependent manner. When cells were treated with inhibitors of mitogen-activated protein kinases (MAPKs), the extracellular signal-regulated kinase (ERK) inhibitor FR180240 inhibited IL-1β-induced IL-6 mRNA expression, but not SP600125 or SKF86002, which are c-Jun N-terminal kinase (JNK) and p38 MAPK inhibitors, respectively. In cells treated with U0126, an inhibitor of MAPK/ERK kinase (MEK), which activates ERK, IL-1β-induced IL-6 mRNA expression was also inhibited. IL-1β stimulated ERK1/2 phosphorylation. In cells transfected with ERK1 and ERK2 isoform siRNAs, IL-1β-induced IL-6 mRNA expression was reduced. These observations suggest that IL-1β induces IL-6 expression via ERK1/2 signaling pathway in canine dermal fibroblasts.

Effect of interleukin-1β on occludin mRNA expression in the duodenal and colonic mucosa of dogs with inflammatory bowel disease

BACKGROUND

Mucosal imbalance of interleukin (IL)-1β and IL-1 receptor antagonist (Ra) has been reported in the duodenal mucosa of dogs with inflammatory bowel disease (IBD). However, the imbalance in the colonic mucosa and its role in duodenitis and colitis in IBD of dogs remain unclear.

OBJECTIVES

To measure the expression of IL-1β and IL-1Ra proteins in the colonic mucosa of dogs with IBD, and to determine the effect of IL-1β on expression of occludin (ocln) mRNA, a tight junction component, in the duodenal and colonic mucosa of dogs with IBD.

ANIMALS

Twelve dogs with IBD and 6 healthy dogs.

METHODS

IL-1β and IL-1 Ra proteins in the colonic mucosa were quantified by ELISA in 7 of the 12 dogs with IBD. Expression of ocln mRNA in the duodenal and colonic mucosa was examined in the 12 dogs by real-time PCR.

RESULTS

The ratio of IL-1β to IL-1Ra in the colonic mucosa was significantly higher in dogs with IBD than in healthy dogs. The ex vivo experiment determined that IL-1β suppressed expression of ocln mRNA in the colonic mucosa, but not in the duodenal mucosa, of healthy dogs. Expression of ocln mRNA in the colonic mucosa, but not in the duodenal mucosa, was significantly lower in dogs with IBD than in healthy dogs.

CONCLUSIONS AND CLINICAL IMPORTANCE

A relative increase in IL-1β may attenuate ocln expression, leading to intestinal barrier dysfunction and promotion of intestinal inflammation in the colonic mucosa, but not in the duodenal mucosa, of dogs with IBD.

Cytokine Concentrations Measured by Multiplex Assays in Canine Peripheral Blood Samples

Cytokines are known to play important roles in a wide range of pathologic conditions spanning all organ systems in every species studied. As our knowledge of the physiology of individual cytokines expands and our ability to measure multiple cytokines in smaller biological samples increases, we gain more insight into the significance and function of each cytokine and the importance of cytokine networks. Previous studies that reported measurements of cytokine concentrations from serum or plasma in dogs with infectious, autoimmune, metabolic, endocrine, and neoplastic diseases yield an appreciation for the complexity of cytokine control and potential applications for cytokine measurements in the diagnosis, prognosis, and therapy of a variety of disease conditions. In this review, we highlight the benefits of multiplex cytokine analysis, summarize clinical and experimental reports that have used this technology in dogs, and discuss the strengths and limitations of data analysis for the interpretation of results in these studies. We describe how differences in technical acuity, data reporting tactics, statistical analysis, study population selection criteria, and cross-sectional experimental design methods may affect interpretation of results from this technology. We also suggest methods for analysis in future studies, such as reporting median fluorescence intensity values, analyzing the proportion of patients above population medians, and performing longitudinal studies.