Introduction Of Serological Tests Research Articles

Serological determinants of COVID-19

BackgroundSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection spreaded rapidly worldwide, as far as it has become a global pandemic. Therefore, the introduction of serological tests for determination of IgM and IgG antibodies has become the main diagnostic tool, useful for tracking the spread of the virus and for consequently allowing its containment. In our study we compared point of care test (POCT) lateral flow immunoassay (FIA) vs automated chemiluminescent immunoassay (CLIA), in order to assess their specificity and sensibility for COVID-19 antibodies detection.ResultsWe find that different specificities and sensitivities for IgM and IgG tests. Notably IgM POCT FIA method vs CLIA method (gold standard) has a low sensitivity (0.526), while IgG POCT FIA method vs CLIA method (gold standard) test has a much higher sensitivity (0.937); further, with respect of IgG, FIA and CLIA could arguably provide equivalent information.ConclusionsFIA method could be helpful in assessing in short time, the possible contagiousness of subjects that for work reasons cannot guarantee “social distancing”.

PTH-091 Is the diagnosis of coeliac disease associated with socio-economic status? A population-based study: Abstract PTH-091

Introduction The rate of diagnosis of coeliac disease in developed countries has increased dramatically since the introduction of serological tests without an obvious environmental precipitant. Little is known about the socio-economic distribution of coeliac disease; there is some evidence that it is less common in more deprived social groups.1 We quantified the incidence of new diagnoses of coeliac disease by socio-economic status in a large, contemporary and population-based cohort. Methods The postcode of residence at diagnosis in consecutive incident adult cases of coeliac disease (n = 837) between January 2000 and December 2006 at Nottingham University Hospital and Royal Hallamshire Hospital was used to determine the Index of Multiple Deprivation 2007 (IMD07) score.2 Incidence rates were calculated using the total adult population for Sheffield and Nottingham derived from UK 2001 National Census categorised into corresponding IMD07 quintiles and Poisson models were fitted. Results There was a strong, independent graded association between the incidence rate of new diagnoses of coeliac disease and socio-economic status. The incidence rate of coeliac disease was twice as high for the least deprived quintile (age- and sex-adjusted IRR* 1.93, 95% CI 1.61 to 2.44) compared with the most deprived quintile. Socio-economic status in incident coeliac disease was not associated with more severe coeliac disease (OR for quintile V to quintile I for presence of malabsorption 1.04, 95% CI 0.47 to 2.28; and for Marsh 3b, 3c histological change OR 0.87, 95% CI 0.56 to 1.34) (Abstract 091). Conclusion The rate of new diagnoses of coeliac disease was twice as high in people from affluent areas compared with that in people living in poorer areas. This striking difference could be due to variation in environmental exposures such as breastfeeding practices3 or could be accounted for by differences in uptake and utilisation of health services.

Wegener’S Granulomatosis: A Review of 5 Cases

Wegener granulomatosis is a systemic disease with a wide spectrum of clinical manifestations. This is illustrated by 5 case reports. The diagnostic value of clinical, radiological, histological and serological signs are discussed and compared with the literature. Diagnosis has been facilitated by the introduction of serological tests: (anti-cytoplasmic antibody (ACPA) titer). High remission rates can be obtained with combined cyclophosphamide and prednisolone treatment. In case of a rapidly progressive glomerulonephritis, plasmapheresis presents a possible therapeutic advantage.

10. AN OUTBREAK OF BELLS'S PALSY CAUSED BY BORRELIA BURGDORFERI IN HUNGARY

The first LGB patients in Hungary were diagnosed in 1984, and a few more in 1985. But only following the introduction of serological tests (indirect immunofluorescence) in 1986 that interest in the illness was aroused. During the last two years more than 2000 sera and CSF samples from 1400 patients have been tested for Borrelia burgdorferi antibody. 92 of 1400 patients suffered from peripheral facial palsy. 35/92 were found to be serologically positive. 19 of them were seen during the summer and fall of 1987. In this year twice as many Dell's palsy patients were seen in our hospitals than in previous years. Of the 35 clinically and serologically proven cases: 14 showed ECM; 10 had other neurological manifestations (Bannwarth's syndrome); 1 had frank arthritis; 1 had carditis. 18/33 seropositlve Bell's palsy patients were children. The clinical picture, epidemiology, serology and CSF findings of these cases will be discussed. Almost all of the seropositive patients became free of symptoms. The longest period of recovery was 100 days. Residual symptom was found only in those patients that remained seronegative during a minimum of 45 days serological follow-up period or did not receive adequate parenteral antibiotic therapy. Half of the seropositlve patients had lymphocytlc meningitis. Only one seronegative case had pleocytosis in the CSF.

Identification and Characterization of Antigenic Components of Sheep Hydatid Fluid by Immunoelectrophoresis

Sheep hydatid fluid was analyzed by immunoelectrophoretic methods. Nineteen antigenic components were detected. Tests with homologous and heterologous antisera showed that ten of the bands were of parasite origin. The characteristic features and staining reactions of each band were determined. In a group of diagnostic sera, eight of the ten parasite bands were identified. The host components which produce cross-reactions in diagnostic sera and with antinormal human serum were identified. The role of host components as a cause of nonspecific reactions and the importance of using antigenic fractions free of host components are discussed. The contents of human or animal hydatid cysts have served as antigen since the introduction of serological tests for hydatidosis. Cyst materials have been obtained from naturally infected man, sheep, pig, cow, and horse. Grafia (1946) and Norman et al. (1957) obtained reproducible results with cysts from one animal source for a particular test, but Bensted and Atkinson (1953) and Garabedian et al. (1957) did not find consistent differences attributable to the source of the antigen. In the Parasitology Unit of the Communicable Disease Center, studies of echinococcus antigens and their sensitivity in immunodiagnostic tests have been under investigation for several years (Kagan and Norman, 1963a, b; Kagan, 1963). In recent research an analysis of sheep hydatid fluid (SHF) was reported with emphasis on characterization of host and parasite antigens by double diffusion methods (Norman et al., 1964). The usefulness of immunoelectrophoresis for the analysis of the antigenic mosaic of parasites has been reported by various workers (Biguet et al., 1962a, b; Received for publication 30 April 1964. * Present address: Department of Microbiology, University of Navarra School of Medicine, Pamplona, Spain. This study was made during the tenure of a fellowship from the Juan March Foundation, Madrid, Spain. Chordi et al., 1964; Norman et al., 1964). In this paper studies of SHF analyzed by immunoelectrophoretic methods are reported. The number of antigen-antibody systems in SHF visualized by this method was determined and antigenic components of parasite and host origin were identified. Attempts were also made to determine which antigenic components were active in detecting antibody in the sera of humans infected with hydatid disease. To isolate parasite from host components, hydatid fluid was absorbed with host serum. The immunoelectrophoretic bands which were missing on subsequent immunoelectrophoresis were listed as host components. The electrophoretic mobility of the hydatid fluid components was determined and the specific stainng characteristics of some antigenic bands were investigated. Such information is of value for the preparation of more specific antigenic fractions for use in diagnostic serology. MATERIAL AND METHODS One liter of pooled sheep hydatid fluid (SHF) was dialyzed 24 hr in running tap water and concentrated approximately tenfold by pervaporation. The cyst fluid contained 0.333 mg N/ml after concentration. The same lot of material was used for all experiments. The antigen was stored at -20 C with merthiolate added as a preservative (1: 10,000). A normal sheep serum (NSS) and a normal human serum (NHS) were collected and preserved with 1: 10,000 merthiolate.