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- Bergman, Daniel, et al.
(author)
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Characterization of canine anti-mouse antibodies highlights that multiple strategies are needed to combat immunoassay interference
- 2019
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In: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 9
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Journal article (peer-reviewed)abstract
- Immunoassays are widely used for detection and quantification of analytes in biological samples, but are vulnerable to analytical errors caused by interfering sample substances. Of particular interest are endogenous anti-animal antibodies that may bind to the immunoassay antibodies and cause erroneous test results. This phenomenon is a hazard to patient safety in both human and veterinary medicine. Here, we demonstrate that anti-mouse antibodies in dogs bind selectively to different regions of the murine IgG molecule, cross-react with IgG from different species, and consist of all major antibody classes present in canine serum (IgA, IgG and IgM). The antibody characteristics varied among individuals and their prevalence differed between two dog breeds. The selective binding to different IgG regions suggests that the antibodies might not originate from immunization through exposure to mice or other species. These findings show that canine anti-mouse antibodies are highly heterogeneous in nature and therefore require a combination of strategies to be counteracted.
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- Bergman, Daniel, et al.
(author)
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Investigation of interference from canine anti-mouse antibodies in hormone immunoassays
- 2019
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In: Veterinary clinical pathology. - : Wiley. - 0275-6382 .- 1939-165X. ; 48:S1, s. 59-69
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Journal article (peer-reviewed)abstract
- BACKGROUND: Canine anti-mouse antibodies are a potential source of immunoassay interference, but erroneous immunoassay results are not always easily identifiable. Anti-Müllerian hormone (AMH) is a marker for the presence of gonads in dogs, but elevated AMH concentrations in neutered dogs could also be caused by antibody interference. For other assays, a discrepant result obtained after antibody precipitation might indicate antibody interference.OBJECTIVES: We aimed to evaluate if canine anti-mouse antibodies are a source of erroneous results in the AMH assay and if antibody precipitation with polyethylene glycol (PEG) is a useful tool for detecting antibody interference in a variety of immunoassays used in the veterinary clinical laboratory.METHODS: Twenty-nine positive and 25 negative samples for anti-mouse antibodies were analyzed for AMH, canine total thyroxine (TT4), canine thyroid-stimulating hormone (TSH) and progesterone before and after treatment with PEG. Results that differed by more than four SDs from the intra-assay coefficients of variation were considered discrepant. Elevated AMH concentrations in neutered dogs with anti-mouse antibodies and no visible gonads present were considered evidence of interference.RESULTS: Evidence of antibody interference was found in two samples analyzed for AMH. The presence of anti-mouse antibodies did not lead to a higher proportion of discrepant results after PEG treatment for any of the immunoassays. The overall incidence of discrepant results for healthy controls was very high (73%).CONCLUSIONS: Canine anti-mouse antibodies are a source of erroneous AMH results. Antibody precipitation with PEG is not a useful tool for detecting interference caused by such antibodies.
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- Bergman, Daniel, et al.
(author)
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Prevalence of interfering antibodies in dogs and cats evaluated using a species-independent assay.
- 2018
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In: Veterinary clinical pathology. - : Wiley. - 0275-6382 .- 1939-165X. ; 47:2, s. 205-212
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Journal article (peer-reviewed)abstract
- BACKGROUND: Interfering antibodies in human serum and plasma are known to react with mammalian antibodies in immunoassays and cause false-positive test results. Although this phenomenon was recently shown in companion animals, knowledge regarding immunoassay interference in veterinary medicine is very limited.OBJECTIVES: The aims of this study were to set up a species-independent immunoassay procedure to detect interference in serum samples, to screen for interference in a cross-section of canine and feline patient samples from an animal hospital, and to determine if the detected interference could be neutralized using an immunoassay based on nonmammalian reagents.METHODS: A 2-site sandwich-type interference assay was set up using commercially available mouse reagents. A total of 369 serum samples from 320 dogs and 263 samples from 218 cats were analyzed using the interference assay. Multiple samples were submitted from 36 dogs and 39 cats. Nineteen samples identified as interference-positive were analyzed in an assay using chicken antibodies.RESULTS: Interference was detected in samples from 28 dogs (9%) and 10 cats (5%) screened with the interference assay. Except for 1 cat, consistent results were obtained for all 75 dogs and cats that submitted more than 1 sample. The interference was eliminated when analyzed in the chicken-based assay (P < .001).CONCLUSIONS: Substances with reactivity toward mouse IgG can be detected in serum samples from dog and cat patients using a 2-site interference assay. The detected substances are most likely interfering antibodies, possibly originating from immunization with other mammalian species.
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- Bremer, Hanna, et al.
(author)
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Disease patterns and incidence of immune-mediated disease in insured Swedish Nova Scotia Duck Tolling Retrievers
- 2015
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In: Veterinary Record. - : Wiley. - 0042-4900 .- 2042-7670. ; 177
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Journal article (peer-reviewed)abstract
- In this study, morbidity in insured Nova Scotia Duck Tolling Retriever (NSDTR) dogs from Sweden was investigated and compared with all other breeds and other retriever breeds. In addition to describing common morbidities in NSDTRs, the hypotheses that NSDTRs are predisposed to lymphoma, immune-mediated rheumatic disease (IMRD) and steroid-responsive meningitis-arteritis (SRMA) were tested. Included in the study were 445,336 dogs; of which, 2890 were NSDTRs that had been covered by veterinary insurance from the Agria Insurance Company (Stockholm, Sweden) at some point during the years 1995-2006. Incidences of various health problems were calculated using the number of veterinary visits as the numerator and the exact time at risk as the denominator. Overall, morbidity was higher in NSDTRs compared with all other breeds, but similar compared with other retriever breeds. The most common causes of veterinary visits in NSDTRs were injuries, gastrointestinal disease and locomotor disorders, with NSDTRs at increased risk of these compared with all other breeds. The incidences for IMRD, SRMA and lymphoma were significantly higher in NSDTRs than in all other dog breeds and all other retriever breeds. The study describes morbidity in NSDTRs, and identifies several disorders to which the breed is predisposed.
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- Bremer, Hanna, et al.
(author)
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Identification of specific antinuclear antibodies in dogs using a line immunoassay and enzyme-linked immunosorbent assay
- 2015
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In: Veterinary Immunology and Immunopathology. - : Elsevier BV. - 0165-2427 .- 1873-2534. ; 168:3-4, s. 233-241
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Journal article (peer-reviewed)abstract
- Circulating antinuclear antibodies (ANA) are commonly present in the systemic autoimmune disease Systemic Lupus Erythematosus (SLE) and in other systemic rheumatic diseases, in humans as well as in dogs. The indirect immunofluorescence (IIF)-ANA test is the standard method for detecting ANA. Further testing for specific ANA with immunoblot techniques or ELISAs is routinely performed in humans to aid in the diagnosis and monitoring of disease. Several specific ANA identified in humans have been identified also in suspected canine SLE but, in contrast to humans, investigation of autoantibodies in canine SLE is mainly restricted to the IIF-ANA test. Our aim was to identify both known and novel specific ANA in dogs and to investigate if different IIF-ANA patterns are associated with different specific ANA in dogs. Sera from 240 dogs with suspicion of autoimmune disease (210 IIF-ANA positive (ANA(pos)) and 30 IIF-ANA negative (ANA(neg))) as well as sera from 27 healthy controls were included. The samples were analysed with a line immunoassay, LIA (Euroline ANA Profile 5, Euroimmun, Lubeck, Germany) and four different ELISAs (Euroimmun). The ANA(pos) dogs were divided in two groups depending on the type of IIF-ANA pattern. Of the 210 ANA(pos) samples 68 were classified as ANA homogenous (ANA(H)) and 141 as ANA speckled (ANA(S)), one sample was not possible to classify. Dogs in the ANA(H) group had, compared to the other groups, most frequently high levels of anti-double stranded deoxyribonucleic acid (dsDNA) and anti-nucleosome ANA. Anti-dsDNA antibodies were confirmed in some dogs with the Crithidia luciliae indirect immunofluorescence test (CLIFT).The frequency of ANA(H) dogs with values above those observed in the healthy group was significantly higher compared to ANA(S) dogs for anti-dsDNA, anti-nucleosome, and anti-histone reactivity. Dogs in the ANA(S) group had, compared to the other groups, most frequently high levels of anti-ribonucleoproteins (RNP) and/or anti-Smith (Sm) antibodies. Reactivity against Sjogren's syndrome related antigens (SS)-A (including the Ro-60 and Ro-52 subcomponents), SS-B, histidyl tRNA synthetase (Jo-1), topoisomerase I antigen (Scl-70), polymyositis-scleroderma antigen (PM-Scl) and proliferating cell nuclear antigen (PCNA) was also noted in individual dogs. In conclusion, by using a commercial LIA and different ELISAs originally developed for detection of human ANA, we identified several specific ANA in serum samples from dogs sampled for IIF-ANA testing. Further, we found that the types of IIF-ANA pattern were associated with reactivity against some particular nuclear antigens.
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- Bremer, Hanna, et al.
(author)
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ILF2 and ILF3 are autoantigens in canine systemic autoimmune disease
- 2018
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In: Scientific Reports. - : NATURE PUBLISHING GROUP. - 2045-2322. ; 8
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Journal article (peer-reviewed)abstract
- Dogs can spontaneously develop complex systemic autoimmune disorders, with similarities to human autoimmune disease. Autoantibodies directed at self-antigens are a key feature of these autoimmune diseases. Here we report the identification of interleukin enhancer-binding factors 2 and 3 (ILF2 and ILF3) as autoantigens in canine immune-mediated rheumatic disease. The ILF2 autoantibodies were discovered in a small, selected canine cohort through the use of human protein arrays; a method not previously described in dogs. Subsequently, ILF3 autoantibodies were also identified in the same cohort. The results were validated with an independent method in a larger cohort of dogs. ILF2 and ILF3 autoantibodies were found exclusively, and at a high frequency, in dogs that showed a speckled pattern of antinuclear antibodies on immunofluorescence. ILF2 and ILF3 autoantibodies were also found at low frequency in human patients with SLE and Sjogren's syndrome. These autoantibodies have the potential to be used as diagnostic biomarkers for canine, and possibly also human, autoimmune disease.
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- Bremer, Hanna, et al.
(author)
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Serum C-reactive protein concentrations in Nova Scotia Duck Tolling Retrievers with immune-mediated rheumatic disease
- 2017
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In: Acta Veterinaria Scandinavica. - : Springer Science and Business Media LLC. - 0044-605X .- 1751-0147. ; 59
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Journal article (peer-reviewed)abstract
- Nova Scotia Duck Tolling Retrievers (NSDTRs) are a dog breed often affected by immune-mediated rheumatic disease (IMRD), a disorder characterised by chronic stiffness and joint pain. Most, but not all, dogs with IMRD, have antinuclear antibodies (ANA), which are also commonly present in the autoimmune disease systemic lupus erythematosus (SLE). The clinical and diagnostic findings of IMRD indicate that it is an SLE-related disorder. C-reactive protein (CRP), an acute phase protein, is a quantitative marker of inflammation for many diseases and is used for diagnosing and monitoring systemic inflammation in both humans and dogs. However, in human SLE, CRP concentrations are often elevated but correlate poorly with disease activity; they can be low in individual patients with active disease. The aim of the study was to investigate CRP in a group of NSDTRs with the SLE-related disorder IMRD. The hypothesis was that CRP concentrations would be increased in dogs with IMRD compared to healthy dogs, but that the increase would be mild. Serum CRP concentrations were measured in 18 IMRD-affected NSDTRs and 19 healthy control NSDTRs using two different canine-specific CRP assays. Dogs with IMRD and ANA had higher CRP concentrations than the control dogs, but the concentrations were below the clinical decision limit for systemic inflammation for most of the IMRD dogs. These results indicate that CRP concentrations were increased in dogs with IMRD and ANA, but the increase was mild, similar to what has been observed in human SLE.
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- Farias, Fabiana H. G., et al.
(author)
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A rare regulatory variant in the MEF2D gene affects gene regulation and splicing and is associated with a SLE sub-phenotype in Swedish cohorts
- 2019
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In: European Journal of Human Genetics. - : Springer Science and Business Media LLC. - 1018-4813 .- 1476-5438. ; 27, s. 432-441
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Journal article (peer-reviewed)abstract
- Systemic lupus erythematosus (SLE) is an autoimmune disorder with heterogeneous clinical presentation and complex etiology involving the interplay between genetic, epigenetic, environmental and hormonal factors. Many common SNPs identified by genome wide-association studies (GWAS) explain only a small part of the disease heritability suggesting the contribution from rare genetic variants, undetectable in GWAS, and complex epistatic interactions. Using targeted re-sequencing of coding and conserved regulatory regions within and around 215 candidate genes selected on the basis of their known role in autoimmunity and genes associated with canine immune-mediated diseases, we identified a rare regulatory variant rs200395694:G > T located in intron 4 of the MEF2D gene encoding the myocyte-specific enhancer factor 2D transcription factor and associated with SLE in Swedish cohorts (504 SLE patients and 839 healthy controls, p = 0.014, CI = 1.1-10). Fisher's exact test revealed an association between the genetic variant and a triad of disease manifestations including Raynaud, anti-U1-ribonucleoprotein (anti-RNP), and anti-Smith (anti-Sm) antibodies (p = 0.00037) among the patients. The DNA-binding activity of the allele was further studied by EMSA, reporter assays, and minigenes. The region has properties of an active cell-specific enhancer, differentially affected by the alleles of rs200395694:G > T. In addition, the risk allele exerts an inhibitory effect on the splicing of the alternative tissue-specific isoform, and thus may modify the target gene set regulated by this isoform. These findings emphasize the potential of dissecting traits of complex diseases and correlating them with rare risk alleles with strong biological effects.
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- Wilbe, Maria, et al.
(author)
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Multiple Changes of Gene Expression and Function Reveal Genomic and Phenotypic Complexity in SLE-like Disease
- 2015
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In: PLOS Genetics. - : Public Library of Science (PLoS). - 1553-7390 .- 1553-7404. ; 11:6
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Journal article (peer-reviewed)abstract
- The complexity of clinical manifestations commonly observed in autoimmune disorders poses a major challenge to genetic studies of such diseases. Systemic lupus erythematosus (SLE) affects humans as well as other mammals, and is characterized by the presence of antinuclear antibodies (ANA) in patients' sera and multiple disparate clinical features. Here we present evidence that particular sub-phenotypes of canine SLE-related disease, based on homogenous (ANA(H)) and speckled ANA (ANA(S)) staining pattern, and also steroid-responsive meningitis-arteritis (SRMA) are associated with different but overlapping sets of genes. In addition to association to certain MHC alleles and haplotypes, we identified 11 genes (WFDC3, HOMER2, VRK1, PTPN3, WHAMM, BANK1, AP3B2, DAPP1, LAM-TOR3, DDIT4L and PPP3CA) located on five chromosomes that contain multiple risk haplotypes correlated with gene expression and disease sub-phenotypes in an intricate manner. Intriguingly, the association of BANK1 with both human and canine SLE appears to lead to similar changes in gene expression levels in both species. Our results suggest that molecular definition may help unravel the mechanisms of different clinical features common between and specific to various autoimmune disease phenotypes in dogs and humans.
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- Öhlund, Malin, et al.
(author)
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Environmental Risk Factors for Diabetes Mellitus in Cats
- 2017
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In: Journal of Veterinary Internal Medicine. - : WILEY. - 0891-6640 .- 1939-1676. ; 31:1, s. 29-35
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Journal article (peer-reviewed)abstract
- BackgroundDiabetes in cats resembles type 2 diabetes in people. The etiology is not fully understood, but both genetic and environmental factors are believed to contribute. ObjectivesTo assess the associations of environmental risk factors with diabetes in cats. AnimalsCats with a diagnosis of diabetes (n = 396) insured by a Swedish insurance company during years 2009-2013, and a control group (n = 1,670) matched on birth year. MethodsA web-based questionnaire was used in a case-control study. An invitation to participate was sent to owners of 1,369 diabetic cats and 5,363 control cats. The survey contained questions related to the cat's breed, age, sex, neutering status, body condition, housing, access to the outdoors, activity level, diet, eating behavior, feeding routine, general health, stressful events, other pets in the household, medications, and vaccination status. Data were analyzed by multiple logistic regression. ResultsResponse rate was 35% for the diabetic group and 32% for the control group. Indoor confinement, being a greedy eater, and being overweight were associated with an increased risk of diabetes. In cats assessed by owners as being normal weight, there was an association between eating predominantly dry food and an increased risk of diabetes (Odds ratio 3.8; 95% confidence intervals 1.3-11.2). Conclusions and Clinical ImportanceDry food is commonly fed to cats worldwide. The association found between dry food and an increased risk of diabetes in cats assessed as normal weight by owners warrants further attention.
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- Öhlund, Malin, et al.
(author)
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Incidence of Diabetes Mellitus in Insured Swedish Cats in Relation to Age, Breed and Sex
- 2015
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In: Journal of Veterinary Internal Medicine. - : Wiley. - 0891-6640 .- 1939-1676. ; 29:5, s. 1342-1347
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Journal article (peer-reviewed)abstract
- Background: Diabetes mellitus ( DM) is a common endocrinopathy in cats. Most affected cats suffer from a type of diabetes similar to type 2 diabetes in humans. An increasing prevalence has been described in cats, as in humans, related to obesity and other lifestyle factors. Objectives: To describe the incidence of DM in insured Swedish cats and the association of DM with demographic risk factors, such as age, breed and sex. Animals: A cohort of 504,688 individual cats accounting for 1,229,699 cat- years at risk ( CYAR) insured by a Swedish insurance company from 2009 to 2013. Methods: We used reimbursed insurance claims for the diagnosis of DM. Overall incidence rates and incidence rates stratified on year, age, breed, and sex were estimated. Results: The overall incidence rate of DM in the cohort was 11.6 cases ( 95% confidence interval [ CI], 11.0- 12.2) per 10,000 CYAR. Male cats had twice as high incidence rate ( 15.4; 95% CI, 14.4- 16.4) as females ( 7.6; 95% CI, 6.9- 8.3). Domestic cats were at higher risk compared to purebred cats. A significant association with breed was seen, with the Burmese, Russian Blue, Norwegian Forest cat, and Abyssinian breeds at a higher risk compared to other cats. No sex predisposition was found among Burmese cats. Several breeds with a lower risk of DM were identified. Conclusions and clinical importance: Our results verify that the Burmese breed is at increased risk of developing DM. We also identified several previously unreported breeds with increased or decreased risk of DM.
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