ILF2 and ILF3 are autoantigens in canine systemic autoimmune disease.

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 Sjögren's syndrome. These autoantibodies have the potential to be used as diagnostic biomarkers for canine, and possibly also human, autoimmune disease.

Hepatitis E Virus Infection in Dromedaries, North and East Africa, United Arab Emirates, and Pakistan, 1983-2015.

A new hepatitis E virus (HEV-7) was recently found in dromedaries and 1 human from the United Arab Emirates. We screened 2,438 dromedary samples from Pakistan, the United Arab Emirates, and 4 African countries. HEV-7 is long established, diversified and geographically widespread. Dromedaries may constitute a neglected source of zoonotic HEV infections.

Presence of antibodies but no evidence for circulation of MERS-CoV in dromedaries on the Canary Islands, 2015.

In 2012, a new betacoronavirus, Middle East respiratory syndrome coronavirus (MERS-CoV), was identified in humans. Several studies confirmed dromedary camels to be a potential reservoir and a source for human infection. Camels located on the Canary Islands were included in those studies and ca 10% of them were positive for MERS-CoV-specific antibodies. However, these findings could not be correctly interpreted because epidemiological information was not provided. Thus, further investigations were necessary to clarify these results. A total of 170 camels were investigated in this survey, of which seven (4.1%) were seropositive by ELISA. Epidemiological information revealed that all seropositive camels had been imported from Africa 20 or more years prior. We conclude that seropositive camels had contact with MERS-CoV in Africa and that there is no shedding of the virus among camels or people around the farms on the Canary Islands. However, the presence of antibodies in the camel herds should be monitored.

Identification of specific antinuclear antibodies in dogs using a line immunoassay and enzyme-linked immunosorbent assay.

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, Lübeck, 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 Sjögren'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.

Development and laboratory evaluation of a lateral flow device (LFD) for the serodiagnosis of Theileria annulata infection.

Several DNA-based and serological tests have been established for the detection of Theileria annulata infection, including polymerase chain reaction, reverse line blot and loop-mediated isothermal amplification, indirect enzyme-linked immunosorbent assay (ELISA), and competitive ELISA. In this study, we have applied knowledge from the development and application of a recombinant protein-based indirect ELISA and competitive ELISA to establish a rapid test for point-of-care diagnosis of T. annulata infection in the field to be used by the veterinarian. For the development of a lateral flow test, the recombinantly expressed T. annulata surface protein (TaSP) was applied as the test antigen and anti-TaSP antiserum as the control line. TaSP antigen conjugated to colloidal gold particles was used as the detection system for visualization at the test line for the binding of anti-TaSP antibody present in the serum of infected animals. The developed test specifically detected antibodies in the serum of animals experimentally infected with T. annulata and showed no cross-reactivity with serum from animals infected with other tested bovine pathogens (Trypanosoma brucei, Anaplasma marginale, Babesia bigemina, Babesia bovis, and Theileria parva). Testing of field samples was compared to results obtained by other serological tests, resulting in a sensitivity and specificity of 96.3% and 87.5% compared to indirect fluorescence antibody test, 98.7% and 81.8% compared to indirect ELISA, and 100% and 47.6% compared to competitive ELISA. In conclusion, a rapid test for the detection of T. annulata infection (T. annulata lateral flow device, Ta-LFD) has been developed, which is easy to perform, delivers results to be read by the naked eye within 10 min, and is suitable for the detection of infection in field samples.

Field validation of a competitive ELISA for detection of Theileria annulata infection.

In previous studies, Theileria annulata surface protein (TaSP) was identified as an immunodominant antigen and successfully used to develop a recombinant-protein-based indirect enzyme-linked immunosorbent assay (ELISA) for the detection of circulating antibodies in serum of T. annulata-infected animals. To increase the specificity, a competitive ELISA (cELISA) was developed using recombinant TaSP antigen and a monoclonal antibody (1C7) specifically binding to TaSP. Since the cELISA accurately differentiated T. annulata-infected from uninfected animals, a study was performed to analyse the suitability of the cELISA in the field. For this, 230 sera with unknown status from different governorates in the north of Iraq were analysed using both the indirect and competitive ELISA and were compared. There was a significant (p < 0.5 x 10(-19)) correlation (r = 0.556) between the tests, whereby the cELISA detected more sera as negative (44/230) compared to the indirect ELISA (21/270). Accordingly, less sera were determined to be positive in the competitive (186/230) than in the indirect ELISA (209/230). Sensitivity and specificity of the cELISA taking the indirect ELISA as a reference were 84.2% and 52.4%, respectively. Accordingly, the calculated prevalence of T. annulata infection was 90.9%, and the positive predictive value was determined to be 94.6%. Taken together, the cELISA proved its suitability for field application and was found qualified for use in serological surveys to monitor the prevalence of T. annulata infection and to identify carrier animals.