Inhibitory effect of heat‐killed Lactobacillus strain on immunoglobulin E‐mediated degranulation and late‐phase immune reactions of mouse bone marrow‐derived mast cells

This study investigated the in vitro effect of Lactobacillus strains, a major group of probiotic lactic acid bacteria, on immunoglobulin E (IgE)‐ and antigen‐induced mast cell degranulation and subsequent gene expression. Bone marrow‐derived mast cells (BMMCs) from DBA/2 mice were cultured with heat‐killed Lactobacillus strains for 24 h. Some strains significantly inhibited IgE‐ and antigen‐induced β‐hexosaminidase release from BMMCs. Furthermore, Lactobacillus reuteri NBRC 15892, which exhibited the strongest inhibitory activity, significantly reduced the elevated interleukin (IL)‐4, IL‐13, tumor necrosis factor‐α, and cyclooxygenase‐2 expression levels that was induced by 1–2 h of stimulation with IgE and antigens. The suppressive effect of NBRC 15892 strain on BMMC degranulation was significantly reduced in the presence of a toll‐like receptor (TLR)2‐neutralizing antibody. In addition, downregulation of cell surface FcεRIα expression was observed after 6 h of NBRC 15892 treatment. These results suggest that some Lactobacillus strains inhibited IgE‐mediated mast cell degranulation and subsequent late‐phase reactions involving mast cells via a TLR2‐dependent mechanism with FcεRIα downregulation.     

FC‐54 Evaluation of IgE‐mediated late‐phase reactions in the skin of normal placebo‐ and prednisolone‐treated dogs: cellular,cytokine and chemokine responses

IgE‐mediated late‐phase reactions can be induced in the skin of normal and atopic dogs by intradermal injections of anti‐IgE antibody. The histology of these reactions is very similar to that of naturally occurring atopic dermatitis. To characterize the cellular, cytokine and chemokine responses in the skin of placebo‐ and prednisolone‐treated dogs, normal beagles received either placebo or 0.5 mg/kg prednisolone twice daily for three days prior to intradermal injection of polyclonal rabbit anti‐canine IgE. Eight‐millimetre punch biopsy skin samples were taken before injection and at the injection sites after 6, 24 and 48 h. Histological and immunohistochemical examination revealed a rapid cellular influx. Eosinophil and neutrophil numbers increased from <1 to 61.4 ± 14.1, and from 7 to 62.2 ± 10.8 cells/mm², respectively, within 6 h after injection, and remained moderately elevated 48 h later. The numbers of CD1c+, CD3+ and CD4+ mononuclear cells were also increased by 6 h. Taqman analysis demonstrated 2.5‐ to 72‐fold increases in mRNA expression for IL‐13, IL‐5, MCP (CCL2), RANTES (CCL5) and TARC (CCL17). Levels of mRNA for IL‐2, IL‐4, IL‐6, and IFNγ remained negligible. Prednisolone administration suppressed the influx of neutrophils and eosinophils, and the expression of IL‐13, CCL2, CCL5 and CCL17 (33, 97, 58, 86, 73 and 90%, respectively), as well as the influx of CD1c+ and CD3+ cells. These data document the cytokine and chemokine response to anti‐IgE injection and demonstrate the anti‐inflammatory effect of prednisolone. Funding: Schering‐Plough Animal Health.     

C‐reactive protein concentration in dogs with primary immune‐mediated hemolytic anemia

Background: Canine primary immune-mediated hemolytic anemia (IMHA) is associated with a high-mortality rate. C-reactive protein (CRP) is the most important acute-phase protein in dogs and may have value as a marker of prognosis or response to treatment in IMHA. Objective: The objectives of this study were to evaluate serum CRP concentration in dogs with primary IMHA at presentation and during treatment, to assess potential differences based on survival time, and to compare CRP with other laboratory parameters of inflammation and prognosis. Methods: Inclusion criteria for primary IMHA were anemia (PCV<0.30 L/L), a positive Coombs' test or persistent autoagglutination of erythrocytes, and the exclusion of underlying diseases by other diagnostic tests. Dogs were divided into 2 groups based on survival: dogs that were still alive 14 days after start of treatment (group 1) and dogs that died or were euthanized before day 14 (group 2). Serum CRP concentration, a CBC, and a biochemistry profile were performed on days 0, 3, 8, and 14. Serum CRP also was determined in 25 clinically healthy dogs. Results: CRP concentration in the 25 clinically healthy dogs ranged from 0–8.9 μg/mL (median 2.2 μg/mL). Thirty dogs were diagnosed with primary IMHA, 24 in group 1 and 6 in group 2. On day 0, CRP concentration in dogs in both groups (median 224 μg/mL) was increased above the reference interval. In group 1 dogs, median CRP concentration was 242 μg/mL on day 0, 69 μg/mL on day 3, 35 μg/mL on day 8, and 2 μg/mL on day 14. In group 2 dogs, median CRP concentration was 194 μg/mL on day 0, 119 μg/mL on day 3, and 41 μg/mL on day 8; only 1 dog in group 2 survived to day 8. There was a significant correlation between CRP and total WBC concentrations on days 0 and 3 (r=−.598, P=.003). Conclusions: Serum CRP concentration was markedly increased in dogs with primary IMHA. CRP concentration did not differ based on patient survival, but might be a marker for long-term monitoring of these patients.     

ACVIM consensus statement on the treatment of immune‐mediated hemolytic anemia in dogs

Immune‐mediated hemolytic anemia (IMHA) causes severe anemia in dogs and is associated with considerable morbidity and mortality. Treatment with various immunosuppressive and antithrombotic drugs has been described anecdotally and in previous studies, but little consensus exists among veterinarians as to the optimal regimen to employ and maintain after diagnosis of the disease. To address this inconsistency and provide evidence‐based guidelines for treatment of IMHA in dogs, we identified and extracted data from studies published in the veterinary literature. We developed a novel tool for evaluation of evidence quality, using it to assess study design, diagnostic criteria, explanation of treatment regimens, and validity of statistical methods. In combination with our clinical experience and comparable guidelines for humans afflicted with autoimmune hemolytic anemia, we used the conclusions of this process to make a set of clinical recommendations regarding treatment of IMHA in dogs, which we refined subsequently by conducting several iterations of Delphi review. Additionally, we considered emerging treatments for IMHA in dogs and highlighted areas deserving of future research. Comments were solicited from several professional bodies to maximize clinical applicability before the recommendations were submitted for publication. The resulting document is intended to provide clinical guidelines for management of IMHA in dogs. These guidelines should be implemented pragmatically, with consideration of animal, owner, and veterinary factors that may vary among cases.     

Mycophenolic acid in patients with immune‐mediated inflammatory diseases: From humans to dogs

Mycophenolic acid (MPA), a noncompetitive, selective and reversible inhibitor of inosine 5′‐monophosphate dehydrogenase (IMPDH), is an immunosuppressive agent that has a long history in medicine. Mechanistically, the inhibition of IMPDH leads to the selective and eventual arrest of T‐ and B‐lymphocyte proliferation. Mycophenolate mofetil (MMF), the first MPA‐based product to receive marketing approval over two decades ago, was originally indicated for the prophylaxis of organ rejection in human transplant patients. Given its broad immunosuppressive properties and ability to selectively inhibit lymphocyte division and effector functions, the clinical utility of MPA was subsequently explored in a host of autoimmune diseases. Human clinical studies have shown MPA to be safe and effective and support its off‐label administration for immune‐mediated diseases such as lupus, myasthenia gravis and atopic dermatitis. MMF became generically available in the United States in 2008, and its clinical utility is increasingly being explored as a treatment option for dogs with immune‐mediated diseases. This review summarizes the available literature for MPA pharmacokinetics and pharmacodynamics, and the current status of MPA as a treatment for client‐owned dogs diagnosed with immune‐mediated diseases.     

ACVIM consensus statement on the diagnosis of immune‐mediated hemolytic anemia in dogs and cats

Immune‐mediated hemolytic anemia (IMHA) is an important cause of morbidity and mortality in dogs. IMHA also occurs in cats, although less commonly. IMHA is considered secondary when it can be attributed to an underlying disease, and as primary (idiopathic) if no cause is found. Eliminating diseases that cause IMHA may attenuate or stop immune‐mediated erythrocyte destruction, and adverse consequences of long‐term immunosuppressive treatment can be avoided. Infections, cancer, drugs, vaccines, and inflammatory processes may be underlying causes of IMHA. Evidence for these comorbidities has not been systematically evaluated, rendering evidence‐based decisions difficult. We identified and extracted data from studies published in the veterinary literature and developed a novel tool for evaluation of evidence quality, using it to assess study design, diagnostic criteria for IMHA, comorbidities, and causality. Succinct evidence summary statements were written, along with screening recommendations. Statements were refined by conducting 3 iterations of Delphi review with panel and task force members. Commentary was solicited from several professional bodies to maximize clinical applicability before the recommendations were submitted. The resulting document is intended to provide clinical guidelines for diagnosis of, and underlying disease screening for, IMHA in dogs and cats. These should be implemented with consideration of animal, owner, and geographical factors.