Indirect Immunofluorescence Test Research Articles

Molecular and Serological Prevalence of Anaplasma phagocytophilum, A. platys, Ehrlichia canis, E. chaffeenses, E. ewingii, Borrelia burgdorferi, Babesia canis, B. gibsoni and B. vogeli among Clinically Healthy Outdoor Dogs in Serbia.

Data concerning combined molecular and serological prevalence of emerging canine tick-borne pathogens in Serbia are lacking. A large population of outdoor living dogs in Belgrade, Serbia's' capital, present an excellent population for epidemiology study. Blood samples were collected from 111 dogs, including 46 shelter, 31 free roaming, and 34 hunting dogs. Species-specific real-time polymerase chain reaction (PCR) (IDEXX Laboratories, Inc., Westbrook Maine, USA) was applied for the molecular detection of Anaplasma phagocytophilum, A. platys, Ehrlichia canis, Babesia canis, B. gibsoni and B. vogeli. A research based SNAP assay (SNAP® M-A, IDEXX Laboratories, Inc., Westbrook Maine, USA) that uses genus and species-specific peptides was used to asses Anaplasma spp., A. phagocytophilum, A. platys, Ehrlichia spp., E. canis, E. chaffeensis, E. ewingii and Borrelia burgdorferi antibody status. B. canis, B. gibsoni and B. vogeli antibody status was assessed with an indirect immunofluorescence test (MegaCor Diagnostic, Horbranz, Austria). Anaplasma spp. and Ehrlichia spp. DNA was not amplified. One quarter of the dogs were A. phagocytophilum, one dog was A. platys, one was E. ewingii and two dogs were B. burgdorferi seroreactive with the SNAP® M-A. Babesia canis or B. gibsoni DNA was amplified by PCR from 16.2% of dogs, whereas 67.6% were seroreactive to one or more Babesia spp. Babesia vogeli was not PCR amplified. We conclude that outdoor dogs in this territory are reservoirs for B. canis and B. gibsoni and are frequently co-exposed to combinations of Anaplasma and Babesia spp.

Performance analysis of automated evaluation of antinuclear antibody indirect immunofluorescent tests in a routine setting

PurposeIndirect immunofluorescence (IIF) on the human epithelial cell-line HEp-2 (or derivatives) serves as the gold standard in antinuclear antibody (ANA) screening. IIF, and its evaluation, is a labor-intensive method, making ANA testing a major challenge for present clinical laboratories. Nowadays, several automated ANA pattern recognition systems are on the market. In the current study, the EUROPattern Suite is evaluated for its use in daily practice in a routine setting.MethodsA total of 1033 consecutive routine samples was used to screen for ANA. Results (positive/negative ANA screening, pattern identification and titer) were compared between software-generated results (EUROPattern) and visual interpretation (observer) of automatically acquired digital images.ResultsConsidering the visual interpretation as reference, a relative sensitivity of 99.3% and a relative specificity of 88.9% were obtained for negative and positive discrimination by the software (EPa). A good agreement between visual and software-based interpretation was observed with respect to pattern recognition (mean kappa: for 7 patterns: 0.7). Interestingly, EPa software distinguished more patterns per positive sample than the observer (on average 1.5 and 1.2, respectively). Finally, a concordance of 99.3% was observed within the range of 1 titer step difference between EPa and observer.ConclusionsThe ANA IIF results reported by the EPa software are in very good agreement with the results reported by the observer with respect to being negative/positive, pattern recognition and titer, making automated ANA IIF evaluation an objective and time-efficient tool for routine testing.

Monoclonal antibody resistant mutant of Peste des petits ruminants vaccine virus.

The available vaccines for control of Peste des petits ruminants do not favour differentiation of infected and vaccinated animals (DIVA). Hence, the present study was aimed to isolate and characterize monoclonal antibody resistant mutant of an Indian strain of vaccine virus "PPRV-Sungri/96" under selection pressure of virus neutralizing monoclonal antibody '4B11' specific to haemagglutinin (H) protein. We successfully isolated five monoclonal antibody resistant (mAr) mutants (PPRV-RM5, PPRV-RM6, PPRV-RM7, PPRV- E6 and PPRV- E7). The mAr mutants did not react with the anti-H mAb 4B11 whereas reacted with control anti-nucleoprotein mAb 4G6, similar to the parent vaccine virus "PPRV-Sungri/96" in indirect ELISA, cell ELISA and indirect immunofluorescence test. Cytometry analysis of mAr mutants revealed loss of binding to mAb 4B11 while maintaining binding to mAb 4G6, more or less similar to "PPRV-Sungri/96". The sequence analysis of the H-protein gene of the mAr mutants resulted in identification of two nucleotide changes leading to amino acid substitutions at position 263 and 502 (L263P and R502P) of the H protein indicating that the epitope of mAb 4B11 could be conformational in nature. Though, mAr mutant grew to a similar titre as parent vaccine virus (PPRV-Sungri/96), the in vivo work in goats to study the mAr mutant as possible negative marker vaccine candidate could not be successfully proved with mAb 4B11 based competitive ELISA. However, one of the nucleotide change (T-C) at position 788, unique to mAr mutant virus resulted in abolition of a restriction enzyme recognition site (BglII). This could be used to differentiate mAr mutant vaccine virus from other available vaccine and field strains using restriction fragment length polymorphism. However, the mAr mutant PPRV-E6 cannot be used as a candidate strain for DIVA vaccine as immune response against it cannot be differentiated based on serology.

Occurrence of brucellosis, leptospirosis and neosporosis in cows with retained placenta in Southwest Paraná, Brazil

ABSTRACT: The aim of this study was to measure the occurrence of brucellosis, leptospirosis and neosporosis in cows from 25 family farms milk, with semi-intensive grazing system, located in the Southwest region of Paraná, Brazil. Eighty-four cows with retained placenta, between July 2013 to July 2014, diagnosed by the presence of fetal membranes in the uterus up to 12 hours after partum, decrease of appetite and of milk production, as well increase of rectal temperature were included into the study. The animals were submitted to blood collection for evaluating the seropositivity for brucellosis, leptospirosis and neosporosis. The blood was collected at 15 to 45 days postpartum, avoiding false negative results due to immune deficiency observed in the transition period. After collection, the blood was centrifuged, the serum was packed in three aliquots, identified and subsequently frozen. Serology was performed to diagnose brucellosis (technique of buffered acidified antigen), leptospirosis (through the microscopic agglutination test - MAT) and neosporosis (indirect immunofluorescence test). Animals were considered positive when presenting titer >1:100 (leptospirosis) and 1:200 (neosporosis). No animal with placenta retention presented Brucella abortus bacteria; 39% (33/84) were reactive to one or more Leptospira serovars, 15% (13/84) were positive to Neospora caninum, and 4% (4/84) had both diagnosis, being reactive for leptospirosis and neosporosis. In conclusion, data from this experiment inspires greater attention to leptospirosis and neosporosis in dairy cattle presenting placenta retention in southwest Paraná.

Clinical and Histological Features of Phospholipase A2 Receptor-Associated and Thrombospondin Type-I Domain-containing 7A-Associated Idiopathic Membranous Nephropathy: A Single Center Retrospective Study from China

BackgroundM-type phospholipase A2 receptor (PLA2R) was identified as the major target antigen in idiopathic membranous nephropathy (IMN). Another target antigen, namely thrombospondin type-1 domain-containing 7A (THSD7A), was recently detected in approximately 10% of non-PLA2R-associated IMN. In this single center retrospective study, clinical and histological features of PLA2R-associated and THSD7A-associated IMN patients were evaluated.Material/MethodsA total of 192 IMN patients, who were receiving no glucocorticoids or immunosuppressant before renal biopsy, were enrolled in this study and followed for a median duration of 25.5 months. IMN with enhanced glomerular PLA2R and THSD7A staining by immunohistochemistry (IHC) were designated as PLA2R-associated IMN and THSD7A-associated IMN respectively. Serum anti-PLA2R and anti-THSD7A antibodies levels were assessed by enzyme linked immunosorbent assay and indirect immunofluorescence testing in PLA2R-associated and THSD7A-associated IMN.ResultsOf 192 IMN patients, 164 patients (85.4%) had PLA2R-associated IMN and 3 patients (1.6%) had THSD7A-associated IMN. Compared with non-PLA2R-associated IMN patients, the 24-hour urinary protein levels were significantly higher (P=0.008), whereas, the proteinuria remission rates were significantly lower (P=0.03) in PLA2R-associated IMN patients. No pathological differences were found between PLA2R-associated IMN and non-PLA2R-associated IMN. Among 3 THSD7A-associated IMN patients, 1 patient had elevated serum anti-THSD7A antibody levels, which was below detectable levels after achieving partial proteinuria remission with combined glucocorticoid and cyclosporine treatment.ConclusionsCompared with non-PLA2R-associated IMN patients in our cohort, PLA2R-associated IMN patients presented with more severe proteinuria and lower remission rates after treatment, with no distinct histological differences. Glomerular expression of PLA2R could be a useful marker to indicate the severity, treatment response, and prognosis of IMN.

Expression profiling of Trypanosoma congolense genes during development in the tsetse fly vector Glossina morsitans morsitans

BackgroundThe tsetse transmitted parasitic flagellate Trypanosoma congolense causes animal African trypanosomosis (AAT) across sub-Saharan Africa. AAT negatively impacts agricultural, economic, nutritional and subsequently, health status of the affected populace. The molecular mechanisms that underlie T. congolense’s developmental program within tsetse are largely unknown due to considerable challenges with obtaining sufficient parasite cells to perform molecular studies.MethodsIn this study, we used RNA-seq to profile T. congolense gene expression during development in two distinct tsetse tissues, the cardia and proboscis. Indirect immunofluorescent antibody test (IFA) and confocal laser scanning microscope was used to localize the expression of a putative protein encoded by the hypothetical protein (TcIL3000_0_02370).ResultsConsistent with current knowledge, genes coding several variant surface glycoproteins (including metacyclic specific VSGs), and the surface coat protein, congolense epimastigote specific protein, were upregulated in parasites in the proboscis (PB-parasites). Additionally, our results indicate that parasites in tsetse’s cardia (C-parasites) and PB employ oxidative phosphorylation and amino acid metabolism for energy. Several genes upregulated in C-parasites encoded receptor-type adenylate cyclases, surface carboxylate transporter family proteins (or PADs), transport proteins, RNA-binding proteins and procyclin isoforms. Gene ontology analysis of products of genes upregulated in C-parasites showed enrichment of terms broadly associated with nucleotides, microtubules, cell membrane and its components, cell signaling, quorum sensing and several transport activities, suggesting that the parasites colonizing the cardia may monitor their environment and regulate their density and movement in this tissue. Additionally, cell surface protein (CSP) encoding genes associated with the Fam50 ‘GARP’, ‘iii’ and ‘i’ subfamilies were also significantly upregulated in C-parasites, suggesting that they are important for the long non-dividing trypomastigotes to colonize tsetse’s cardia. The putative products of genes that were upregulated in PB-parasites were linked to nucleosomes, cytoplasm and membrane-bound organelles, which suggest that parasites in this niche undergo cell division in line with prior findings. Most of the CSPs upregulated in PB-parasites were hypothetical, thus requiring further functional characterization. Expression of one such hypothetical protein (TcIL3000_0_02370) was analyzed using immunofluorescence and confocal laser scanning microscopy, which together revealed preferential expression of this protein on the entire surface coat of T. congolense parasite stages that colonize G. m. morsitans’ proboscis.ConclusionCollectively, our results provide insight into T. congolense gene expression profiles in distinct niches within the tsetse vector. Our results show that the hypothetical protein TcIL3000_0_02370, is expressed on the entire surface of the trypanosomes inhabiting tsetse’s proboscis. We discuss our results in terms of their relevance to disease transmission processes.

Immunoglobulin E and bullous pemphigoid.

Clinical features and histological findings in bullous pemphigoid (BP) suggest a Th2-oriented inflammatory reaction, especially in the early stages of the disease. Elevated total serum IgE levels, blood eosinophilia, and elevated serum levels of different soluble inflammatory Th2 response mediators have been described in large cohorts of patients with classic clear-cut BP manifestations. Direct immunofluorescence, indirect immunofluorescence, and anti-BP230 and anti-BP180 IgE ELISA testing show self-reactive IgE autoantibodies in a consistent number of BP patients. Both IgE autoantibodies and a Th2-oriented immune response may play a role in the initial phases of BP and atypical cases of BP, such as severe erythematous and urticarial forms of BP, as well as blister formation. Two recently reported experimental murine models employing IgE autoantibodies against BP180 have been reported and the successful treatment of bullous pemphigoid with the anti-IgE antibody, omalizumab, supports the roles played by IgE autoantibodies in BP pathogenesis.

Comparative study of direct and indirect immunofluorescence for diagnosis of canine pemphigus foliaceus

ABSTRACT Pemphigus foliaceus (PF) is the most common autoimmune skin disease in dogs. It is characterized by pustules, erosions, and crusts which occur due to the presence of autoantibodies that target intercellular adhesion. Histopathological examination is considered the gold standard pattern in the diagnosis, but may sometimes be inconclusive, especially when the characteristic findings are not identified. New diagnostic tests are continuously being developed and immunofluorescence assays, could be a valuable alternative diagnostic tool. This study aimed to evaluate the applicability of direct and indirect immunofluorescence (DIF and IIF) tests for the diagnosis of canine PF. Twenty eight dogs were divided into two groups: Group I with 14 dogs with PF and Group II (control) with 14 dogs with Superficial pyoderma (differential diagnoses of PF). All animals were submitted to skin biopsy to histopathological and DIF. Blood samples were collected to assess IIF. Comparing the DIF results against the histopathology test, there was an agreement of 75% (9/12) with a Kappa index of 0.77 (P<0.001). Considering IIF, the agreement was 100% (14/14), with a Kappa index of 1.0 (P<0.001). We conclude that DIF and IIF are highly effective and were useful and effective complementary examination tests for an improvement in the diagnosis of canine PF.

An Outbreak of Human Trichinellosis in the Village of Subotinac near the Town of Aleksinac

Abstract An outbreak of trichinellosis affecting 13 individuals, of whom 8 with severe form presented as myocarditis, occurred in the village of Subotinac near the town of Aleksinac in Serbia. The source of this epidemic was smoked pork from a domestic pig that had not undergone meat inspection procedures. The most striking clinical features among all the 13 patients were muscular pain (84.6%), malaise (69.2%), upper eyelid edema (61.5%), and difficulty in chewing (53.9%). These symptoms and signs were associated with significant elevations of creatine phosphokinase and lactate dehydrogenase levels. As high as 61.5% of the patients with trichinellosis were diagnosed with myocarditis (determined by means of electrocardiography, echocardiography, troponin I and creatine kinase-MB measurements). The patients had Trichinella-specific IgG antibodies in an enzyme-linked immunosorbent assay and positive indirect immunofluorescence test results. Patients seemed to respond well to treatment with mebendazole. Corticosteroid therapy was administered to patients with myocarditis. Since high percentage of our patients presented with myocarditis, an infectious diseases specialist should always keep in mind doing cardiac biomarkers analyses, echocardiography and electrocardiography.

New genetically engineered DFS70 knock-out HEp-2 cells enable rapid and specific recognition of anti-DFS70 antibodies

Background: The correct identification of anti-dense fine speckled-70 (DFS70) antibodies represents an important issue in the detection of anti-nuclear antibodies (ANAs) as performed by the indirect immunofluorescence (IIF) test on HEp-2 substrates. In this study, we have evaluated a new method for anti-DFS70 antibody detection employing HEp-2 cells knocked-out for the DFS70 antigen.Methods: We studied 148 sera with a DFS70-like pattern (91 positive and 57 negative when tested for anti-DFS70 antibodies by a specific chemoluminescence [CLIA] method); 116 sera with infectious disease; 100 healthy donors (HDs), 139 samples from patients with a defined diagnosis of autoimmune rheumatic disease (ARD), and 242 consecutive unselected samples screened for ANA during the routine work-up.Results: The HEp2 DFS70-Ko substrate recognized anti-DFS70 antibodies in 86/91 (94.5%) of the DFS70 CLIA-positive sera and in 9/57 (15.8%) of the DFS70 CLIA-negative samples. None of the 116 infectious diseases were positive for DFS70 using the engineered IIF substrate. Two samples (2%) were positive among HDs and were then confirmed by CLIA. The 139 ANA-positive sera from patients with ARD displaying a defined antibody specificity showed their expected patterns also on DFS70-Ko HEp-2 substrate. Five of the 242 (2.1%) consecutive samples tested in the routine ANA-screening were identified as DFS70-positive using the HEp2 Ko-substrate and were then confirmed by CLIA.Conclusions: The use of DFS70 HEp-2 Ko cells may offer the unique possibility of simultaneously identifying and confirming the presence of anti-DFS70 antibodies during the standard ANA evaluation, while keeping the expression of other autoantibody markers intact.

Automated Processing and Evaluation of Anti-Nuclear Antibody Indirect Immunofluorescence Testing

Indirect immunofluorescence (IIF) is considered by the American College of Rheumatology (ACR) and the international consensus on ANA patterns (ICAP) the gold standard for the screening of anti-nuclear antibodies (ANA). As conventional IIF is labor intensive, time-consuming, subjective, and poorly standardized, there have been ongoing efforts to improve the standardization of reagents and to develop automated platforms for assay incubation, microscopy, and evaluation. In this study, the workflow and performance characteristics of a fully automated ANA IIF system (Sprinter XL, EUROPattern Suite, IFA 40: HEp-20-10 cells) were compared to a manual approach using visual microscopy with a filter device for single-well titration and to technologist reading. The Sprinter/EUROPattern system enabled the processing of large daily workload cohorts in less than 8 h and the reduction of labor hands-on time by more than 4 h. Regarding the discrimination of positive from negative samples, the overall agreement of the EUROPattern software with technologist reading was higher (95.6%) than when compared to the current method (89.4%). Moreover, the software was consistent with technologist reading in 80.6–97.5% of patterns and 71.0–93.8% of titers. In conclusion, the Sprinter/EUROPattern system provides substantial labor savings and good concordance with technologist ANA IIF microscopy, thus increasing standardization, laboratory efficiency, and removing subjectivity.

Childhood Visceral Leishmaniasis: Distinctive Features and Diagnosis of a Re-emerging Disease. An 11-year Experience From a Tertiary Referral Center in Athens, Greece.

Visceral leishmaniasis (VL) remains a public health issue in Greece. The aim of this study was to describe the clinical and epidemiologic characteristics of pediatric VL in our region as well as to evaluate the laboratory findings and the diagnostic techniques that are applied. We retrospectively reviewed the medical records of all children diagnosed with VL in an 11-year period at a tertiary public hospital in the region of Athens. Demographic features, clinical information and laboratory findings were accessed. A total of 43 cases were recorded during 2005-2015. Median age of the patients was 3.7 years. Pallor (100%), fever (98%), hepatosplenomegaly (55.8%) and appetite loss (32.6%) were the most common presentations of the disease. The predominant laboratory abnormalities were anemia (100%), thrombocytopenia (90.7%), elevated inflammatory markers (86.1%) and decreased albumin/globulin (A/G) ratio (72.1%). Four patients developed secondary hemophagocytic lymphohistiocytosis syndrome, whereas in 3 others abdominal ultrasound showed splenic nodules. Bone marrow aspiration detected Leishmania parasites in 92.7% of cases and the rapid rK39 strip test indicated anti-Leishmania antibodies in 97.1% of children. In addition, all patients in whom indirect immunofluorescent antibody test was implemented had positive results. VL still affects children in our area. Fever, splenomegaly, anemia and appetite loss are the typical findings in children. Noninvasive techniques (immunofluorescent antibody test, rK39) in combination with bone marrow microscopy are useful in the diagnosis of pediatric VL.

Chikungunya virus infection in Aruba: Diagnosis, clinical features and predictors of post-chikungunya chronic polyarthralgia.

BackgroundChikungunya virus (CHIKV) emerged in Aruba for the first time in 2014. We studied the clinical presentation of acute CHIKV infection and the contribution of serologic and molecular assays to its diagnosis. In a cohort of confirmed CHIKV cases, we analysed the frequency, duration and predictors of post-chikungunya chronic polyarthralgia (pCHIK-CPA), defined as joint pains lasting longer than 6 weeks or longer than 1 year.MethodologyPatient sera obtained within 10 days of symptom onset were tested for CHIKV, using an indirect immunofluorescence test for the detection of CHIKV-specific Immunoglobulin M (IgM) and post-hoc, by reverse-transcription polymerase chain reaction (RT-PCR). CHIKV was isolated from selected samples and genotyped. For confirmed CHIKV cases, clinical data from chart review were complemented by a Telephone survey, conducted 18–24 months after diagnosis. When joint pain was reported, the duration, presence of inflammatory signs, type and number of joints affected, were recorded. Joint involvement was scored according to the 2010 ‘American College of Rheumatology/ European League Against Rheumatism’ criteria for seronegative rheumatoid arthritis (ACR-score). Risk factors for pCHIK-CPA were identified by logistic regression.Principal findingsAcute CHIKV infection was diagnosed in 269 of 498 sera, by detection of IgM (n = 105), by RT-PCR (n = 59), or by both methods (n = 105). Asian genotype was confirmed in 7 samples. Clinical data were complete for 171 of 248 (69.0%) patients, aged 15 years or older (median 49.4 [35.0–59.6]). The female-to-male ratio was 2.2. The main acute symptoms were arthralgia (94%), fever (85%), myalgia (85%), headache (73%) and rash (63%). In patients with arthralgia (n = 160), pCHIK-CPA longer than 6 weeks was reported by 44% and longer than 1 year by 26% of cases. Inflammatory signs, stiffness, edema and redness were frequent (71%, 39% and 21%, respectively). Joints involved were knees (66%), ankles (50%), fingers (52%), feet (46%), shoulders (36%), elbows (34%), wrists (35%), hips (31%), toes (28.1%) and spine (28.1%). Independent predictors of pCHIK-CPA longer than 1 year were female gender (OR 5.9, 95%-CI [2.1–19.6]); high ACR-score (7.4, [2.7–23.3]), and detection of CHIKV-RNA in serum beyond 7 days of symptom onset (6.4, [1.4–34.1].ConclusionsWe identified 269 CHIKV patients after the first outbreak of Asian genotype CHIKV in Aruba in 2014–2015. RT-PCR yielded 59 (28%) additional CHIKV diagnoses compared to IgM antibody detection alone. Arthralgia, fever and skin rash were the dominant acute phase symptoms. pCHIK-CPA longer than 1 year affected 26% of cases and was predicted by female gender, high ACR-score and CHIKV-RNA detection beyond 7 days of symptom onset.

SEROLOGICAL COMPARISON STUDY FOR DIAGNOSIS OF TORCH PROFILE AGENTS OF PREGNANT WOMEN IN IRAQ

This study reports the prevalence of Toxoplasma gondii (T.gondii), Rubella virus, Cytomegalovirus (CMV), and Herpes simplex virus (HSV), infections in 1500 serum samples from women with Bad Obstetric History (BOH) like abortion and dead fetuses from Mosul and Baghdad hospitals. These Samples taken as serum, to used it in ELISA (IgM ,IgG) , EUROLINE immunoblot (IgM, IgG) and the indirect immunofluorescence test for BIOCHIPs TORCH-Profile IgG to detect the presence of the TORCH agents, for two years. Three hundred positive samples demonstrating the presence of immunoglobulin IgM and IgG antibodies using ELISA test. IgM antibodies were positive in 44 patients (14.7%) T.gondii, 146 (48.7%) CMV, 37 (12.3%) Rubella, and 177 (59%) HSV II and IgG antibodies were positive in 75 patients (25%) T.gondii, 189 (63%) for CMV, 60 (20%) Rubella, and 232 (77.3%) HSV II. We were selected 30 samples from the 300 which had been shown the presence of IgM antibodies in ELISA kits, to used it in EUROLINE immunoblot. IgM antibodies were positive in 2 patients (6.7%) for CMV, Rubella & HSV I and Nil for T.gondii and HSV II. IgG antibodies were positive in 4 patients (13.3%) for T.gondii, 29 (96.7%) CMV and HSV I, 28 (93.3%) Rubella, 2 (6.7%) HSV II. Also 45 samples were selected from the 300 samples were used in the indirect immunofluorescence test for BIOCHIPs TORCH-Profile IgG positive in 21 patients (46.7%) T.gondii, 45 (100 %) CMV, 31(68.9%) Rubella and 44 (97.8%) HSV I and II.

PM 7/21 (2) Ralstonia solanacearum, R. pseudosolanacearum and R. syzygii (Ralstonia solanacearum species complex)

Specific scopeThis Standard describes a diagnostic protocol for Ralstonia solanacearum, Ralstonia pseudosolanacearum and Ralstonia syzygii, i.e. phylotype/sequevar strain in the Ralstonia solanacearum Species Complex (RSSC).It should be used in conjunction with PM 7/76 Use of EPPO diagnostic protocols.Specific approval and amendmentApproved in 2003‐09. First revised in 2018‐02.

New biochip immunofluorescence test for the serological diagnosis of pemphigus vulgaris and foliaceus: A review of the literature.

The immunoassays that are available for the serological diagnosis of the more common subtypes of autoimmune blistering diseases such as pemphigus vulgaris (PV) and pemphigus foliaceus (PF) include enzyme-linked immunosorbent assay (ELISA) testing to specific antigens desmoglein (Dsg)1 and Dsg3, direct immunofluorescence (DIF), indirect immunofluorescence (IIF), and immunoblotting. A review of the literature on the biochip assay was conducted. Six studies investigated the validity of a new biochip, mosaic-based, IIF test in patients with pemphigus and demonstrated its relatively high sensitivity and specificity (Dsg3: 97.62-100%, 99.6-100%; Dsg1: 90%, 100%) in comparison with ELISA (Dsg3: 81-100%, 94-100%; Dsg1: 69-100%, 61.1-100%), and/or IIF (PV: 75-100%, 91.8-100%; PF: 67-100%) using suitable substrates. So far, validation studies of the biochip have been conducted in four countries (Germany, Italy, Turkey, and Poland) but none in the southern hemisphere. Caucasian patients were recruited as normal controls for these studies; thus, the diagnostic value of the biochip remains uncertain in population groups of other ethnicities. A range of disease control patients were recruited including patients with linear immunoglobulin A dermatosis, psoriasis, discoid lupus erythematosus, lichen planus, and noninflammatory skin diseases (e.g., squamous cell carcinoma, basal cell carcinoma, and vascular leg ulcers). Prospective studies with control patients from a diverse range of ethnicities are needed to better validate the biochip.

Clinical and laboratory diagnosis of tick-borne rickettsioses in areas of low risk of infection Rickettsia sibirica.

For the first time, a comparative description of clinical and laboratory parameters in patients with clinical signs of tick-borne rickettsiosis in a natural focus with a low risk of infection with R. sibirica and circulation of R. raoultii is given, depending on the results of serological verification of the diagnosis. Established almost complete coincidence of clinical and laboratory parameters in patients with tick-borne rickettsiosis, regardless of the presence of antibodies to R. sibirica and / or R. raoultii. It was shown that even the complex use of complement fixation test, indirect immunofluorescent test and ELISA for the detection of antibodies to R. sibirica does not allow verification of the diagnosis in a third part of patients with pathognomonic signs of tickborne rickettsiosis. In seropostive patients, antibodies to R. sibirica prevailed, which makes it impossible to differentiate cases of tick-borne rickettsiosis of different species etiology. The possible reasons of the phenomenon of «seronegativeness» of patients with tick-borne rickettsiosis and approaches to its study are discussed. It is concluded that with the existing diversity and insufficient knowledge of rickettsiae circulating in natural foci, and the current state of laboratory diagnostics, the basis for the diagnosis of «Tick-borne rickettsiosis» should be the clinical and epidemiological signs of this infectious disease, which must be recorded in the established order even no serological verification. For such cases, ICD-10 has two encoding options: A 79.9 - Rickettsiosis, unspecified (infection caused by rickettsia, no other indication) and A 77.9 - Spotted fever, unspecified (tick-borne fever, no other indication) [mkb-10.com].

Celiac disease is uncommon in irritable bowel syndrome in the USA.

Routine serologic testing for celiac disease (CD) may be useful in irritable bowel syndrome (IBS) patients, but this is controversial. We aimed to compare the prevalence of unrecognized CD in a large cohort of patients with and without IBS. This is a family case-control IBS study conducted at a single US academic medical center. Stored serum and DNA were available. Tissue transglutaminase (TTg) immunoglobulin A was performed, followed by indirect immunofluorescence testing for endomysial antibodies with positive or weakly positive TTg results. Individuals were considered to have CD if both results were positive. χ and Fisher's exact tests were used to compare prevalence between the two groups. Serum samples were studied from 533 cases and 531 controls. In all, 80% of participants were female, with a median age of 50 years; 65% of cases and 0% controls met the Rome criteria for IBS. Previous serological testing for CD had occurred in 142 (27%) cases and 13 (2%) controls, but none had CD on subsequent testing. Six (1.1%) cases versus five (0.9%) controls had positive or weakly positive TTg test. Six cases (1.1%) versus three (0.6%) controls were confirmed to have CD by endomysial antibody (P=0.51). No difference in the prevalence of CD between patients with IBS and patients without IBS at a tertiary medical center was observed. Our findings do not support routine celiac serologic or genetic testing in patients with IBS in all US populations.

Borderline positive antineutrophil cytoplasmic antibodies (ANCA)-PR3/MPO detection in a large cohort tertiary center: lessons learnt from a real-life experience.

Enzyme-linked immunosorbent assay (ELISA) and indirect immunofluorescence (IIF) are the best strategies for antineutrophil cytoplasmic antibodies (ANCA) detection. In a minority of subjects, ELISA-based ANCA testing may result in a borderline positive titre. Therefore, we assessed the clinical significance of such a result. This is a retrospective study, which included all subjects screened for ANCA subtypes (myeloperoxidase (MPO) or proteinase-3 (PR3)) with subsequent identification of borderline positive results, as determined by ELISA and retested using IIF. The demographic, clinical and laboratory data of subjects with borderline positive ANCA test results were extracted from their medical records. A total of 14,555 PR3/MPO-ANCA tests were performed with ELISA during the study period (2006-2016). Of the 14,555 PR3-ANCA antibody tests that were performed, 94 were borderline positive (titre 0.9-1.1), and of 14,555 MPO-ANCA antibody tests, 43 were borderline positive (titre 0.9-1.1). The male-to-female ratio was 1:1.08 and the mean age was 50.95±21.79 years. Four MPO-ANCA (9.30%) and 11 PR3-ANCA (11.70%) antibody borderline samples resulted positive on IIF testing. Subjects with borderline positive MPO-ANCA were found to have a poorer outcome in terms of renal failure and the requirement of dialysis. Subjects with borderline positive MPO-ANCA and positive p-ANCA (IIF) seem to have a less favorable outcome. Physicians should be aware of these findings and possibly perform a closer follow-up and routine screening for these subjects.

Reliable Serological Testing for the Diagnosis of Emerging Infectious Diseases.

Climate change, increased urbanization and international travel have facilitated the spread of mosquito vectors and the viral species they carry. Zika virus (ZIKV) is currently spreading in the Americas, while dengue virus (DENV) and chikungunya virus (CHIKV) have already become firmly established in most tropical and also many non-tropical regions. ZIKV, DENV and CHIKV overlap in their endemic areas and cause similar clinical symptoms, especially in the initial stages of infection. Infections with each of these viruses can lead to severe complications, and co-infections have been reported. Therefore, laboratory analyses play an important role in differential diagnostics. A timely and accurate diagnosis is crucial for patient management, prevention of unnecessary therapies, rapid adoption of vector control measures, and collection of epidemiological data.There are two pillars to diagnosis: direct pathogen detection and the determination of specific antibodies. Serological tests provide a longer diagnostic window than direct methods, and are suitable for diagnosing acute and past infections, for disease surveillance and for vaccination monitoring. ELISA and indirect immunofluorescence test (IIFT) systems based on optimized antigens enable sensitive and specific detection of antibodies against ZIKV, DENV and CHIKV in patient serum or plasma. In recent years, Euroimmun (Lübeck, Germany) has developed numerous test systems for the serological diagnosis of (re-)emerging diseases, including a very sensitive and specific anti-ZIKV ELISA.