scholarly journals Immunoassay standardization for the detection of immunoglobulin A (IgA) against Porphyromonas gingivalis antigens in saliva of individuals with and without leprosy

AMB Express ◽  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mariana Costa Calheira ◽  
Soraya Castro Trindade ◽  
Michelle Miranda Lopes Falcão ◽  
Luciana Sales Conceição Barbosa ◽  
Gislene Regina Batista Carvalho ◽  
...  

AbstractLeprosy reactions are immune processes that cause neural damage in individuals with leprosy. As periodontitis is an infectious disease related to its development, specific antibodies to periodontal pathogens must be evaluated to better understand the humoral mechanisms underlying this relationship. Therefore, the objective of this study was to standardize an immunoassay to measure IgA specific to P. gingivalis antigens in the saliva of individuals with leprosy. An ELISA checkerboard titration was performed. A validation test involving 53 individuals with leprosy, 24 with and 19 without periodontitis, was conducted and a ROC curve constructed to calculate sensitivity and specificity. The coefficient of the optical densities was 2.21 and 2.66 for P. gingivalis crude extract and the recombinant protein HmuY, respectively. Sensitivity and specificity for the P. gingivalis crude extract were 66.7% and 73.7%, respectively, and for HmuY, were 62.5% and 52.6%, respectively. Specific recognition of P. gingivalis occurred predominantly in individuals with periodontitis, which validates the use of this test for studying periodontitis in individuals with leprosy.Trial registration CAEE 64476117.3.0000.0049, 21/07/2017, retrospectively registered

2021 ◽  
pp. 109352662199148
Author(s):  
M. Cristina Pacheco ◽  
Nicole Green ◽  
Jane Dickerson ◽  
Dale Lee

Objectives The goal of our study was to determine whether visual assessment of the esophagus and stomach could predict abnormal histology and determine the frequency of interventions based on biopsies in patients undergoing endoscopy for elevated tissue transglutaminase immunoglobulin A antibody (TTG). Methods Pathology records were searched for patients with biopsy performed for elevated TTG. Pathology report, endoscopy report, and follow-up were obtained and slides from the duodenum reviewed. Pathology was considered gold standard for sensitivity and specificity calculations. Results 240 patients were included. 215 patients had esophageal biopsies performed. Esophageal endoscopic visual assessment had sensitivity of 47% and specificity of 93% for abnormal histology. 16(7%) patients had therapy or referral related to results and, of these, 6(38%) had visually normal endoscopy. 237 biopsies were performed of stomach. Gastric endoscopic visual assessment had a sensitivity and specificity of 20% and 87%. 24(10%) patients had therapy based on findings and, of these, 12 (50%) had visually normal endoscopy. Conclusions Endoscopic assessment of esophagus and stomach has low sensitivity and high specificity for pathologic abnormalities when indication for endoscopy is elevated TTG. When endoscopy is visually normal clinical interventions based on biopsy are rare, and foregoing biopsy may be considered.


1994 ◽  
Vol 112 (2) ◽  
pp. 359-365 ◽  
Author(s):  
I. Nachamkin ◽  
S. H. Fischer ◽  
X.-H. Yang ◽  
O. Benitez ◽  
A. Cravioto

SUMMAYWe studied the relationship between IgA anti–campylobacter flagellin antibodies in breast milk samples and protection of breastfed infants living in a rural Mexican village from campylobacter infection. There were fewer episodes of campylobacter infection (symptomatic and asymptomatic combined) in infants breastfed with milk containing specific anti-flagellin antibodies (1.2/child/year, 95% CI 0.6–1.8) versus non–breastfed children (3.3/child/year, 95% CI 1.8–4.8; P < 0.01). Infants breastfed with milk that was antiflagellin antibody negative by ELISA also had fewer episodes of infection compared with non-breastfed children, but the difference did not reach statistical significance (1.8/child/year, 95% CI 0.7–3.0 versus 3.3/child/year, 95% CI 1.8–4.8, P > 0.05). Breastfeeding has a protective effect against campylobacter infection and is associated with the presence of specific antibodies directed against campylobacter flagellin.


2004 ◽  
Vol 38 (5) ◽  
pp. 723-728 ◽  
Author(s):  
Veruska de João Malheiros ◽  
Mario Julio Avila-Campos

OBJECTIVE: To comparatively detect A. actinomycetemcomitans and F. nucleatum from periodontal and healthy sites. METHODS: Subgingival clinical samples from 50 periodontitis adult patients and 50 healthy subjects were analyzed. Both organisms were isolated using a trypticase soy agar-bacitracin-vancomycin (TSBV) medium and detected by PCR. Conventional biochemical tests were used for bacteria identification. RESULTS: A. actinomycetemcomitans and F. nucleatum were isolated in 18% and 20% of the patients, respectively, and in 2% and 24% of healthy subjects. Among A. actinomycetemcomitans isolates, biotype II was the most prevalent. Primer pair AA was 100% sensitive in the detection of A. actinomycetemcomitans from both subject groups. Primers ASH and FU were also 100% sensitive to detect this organism in healthy subject samples. Primer pair FN5047 was more sensitive to detect F. nucleatum in patients or in healthy samples than primer 5059S. Primers ASH and 5059S were more specific in the detection of A. actinomycetemcomitans and F. nucleatum, respectively, in patients and in healthy subject samples. CONCLUSIONS: PCR is an effective tool for detecting periodontal pathogens in subgingival samples, providing a faster and safer diagnostic tool of periodontal diseases. The method's sensitivity and specificity is conditioned by the choice of the set of primers used.


2020 ◽  
Vol 99 ◽  
pp. 578-586 ◽  
Author(s):  
Rosemary Thwaite ◽  
Concepción Berbel ◽  
Manuel Aparicio ◽  
Debora Torrealba ◽  
Mireia Pesarrodona ◽  
...  

Author(s):  
Sarah Hicks ◽  
Kai Pohl ◽  
Teresa Neeman ◽  
Hayley McNamara ◽  
Kate Parsons ◽  
...  

Estimates of seroprevalence of SARS-CoV-2 antibodies have been hampered by inadequate assay sensitivity and specificity. Using an ELISA-based approach to that combines data about IgG responses to both the Nucleocapsid and Spike-receptor binding domain antigens, we show that near-optimal sensitivity and specificity can be achieved. We used this assay to assess the frequency of virus-specific antibodies in a cohort of elective surgery patients in Australia and estimated seroprevalence in Australia to be 0.28% (0 to 0.72%). These data confirm the low level of transmission of SARS-CoV-2 in Australia before July 2020 and validate the specificity of our assay.


2009 ◽  
Vol 63 (1-2) ◽  
pp. 37-44
Author(s):  
Nenad Milic ◽  
Jakov Nisavic ◽  
Marina Radojicic ◽  
Marina Sekler ◽  
Kazimir Matovic ◽  
...  

Comparative investigations of the sensitivity and specificity of the indirect immunoenzyme probe - iELISA and the hemagglutination inhibition test (HI test) in serological diagnostics of the Newcastle disease in poultry were carried out using samples of blood serum taken from non-vaccinated and vaccinated poultry. A total of 14 samples of blood serum from non-vaccinated poultry were examined using the immunoenzyme probe - iELISA, and nine of these were found to be positive to the presence of specific antigen against the Newcastle disease virus, while two samples were suspect, and no presence of specific antibodies was established in three samples. Examinations of 82 samples of blood serum from vaccinated poultry for the presence of specific antibodies against the Newcastle disease virus established their presence in 80 serum samples, while one sample was suspect and one sample was negative. The values of the titer of specific antibodies in blood serum samples of vaccinated and non-vaccinated poultry established using the hemagglutination inhibition test (HI test) ranged from 1:2 to 1:32.


Pteridines ◽  
1995 ◽  
Vol 6 (2) ◽  
pp. 58-62
Author(s):  
Young Shik Park ◽  
Nacksung Kim ◽  
Hajeong Kim ◽  
Dongkook Park ◽  
Jeongbin Yim

Summary 6-Pyruvoyl tetrahydropterin synthase is involved in the synthesis of pteridine eye pigments in Drosophila. The purple gene which was known to be one of the target loci of the suppressor mutation su(sj2 has been identified to encode the enzyme, and its cDNA has been cloned recently. The cDNA encoding the 19.3 kDa subunit of the 6-pyruvoyl tetrahydropterin synthase was expressed as fusion proteins in E. coli. The recombinant protein was shown to be active and purified from the E. coli crude extract by metal-chelation chromatography. The fused metal-chelating oilgopeptide was removed by thrombin for further characterization. Apparent Km for the substrate dihydroneopterin triphosphate was determined to be 590 IlM, which was slightly higher than the value of the native enzyme. The isoelectric point of 6.4 was also different from the known value of 4.3 determined by the native enzyme. Heat stability and the stimulatory effect of reducing agents were similar to the native enzyme. The modification of cysteine residues in the recombinant enzyme, one of which is known to be conserved in human and rat enzymes, by iodoacetamide inhibited its activity by up to 80%.


2016 ◽  
Vol 3 (1) ◽  
Author(s):  
Teresa Lambe ◽  
Tommy Rampling ◽  
Dhan Samuel ◽  
Georgina Bowyer ◽  
Katie J. Ewer ◽  
...  

Abstract Blood sampling to assess production of antigen-specific antibodies after immunization is commonly performed, but it presents logistical difficulties for trials carried out during an infectious disease outbreak. In this study, we show that antibodies may be reliably detected in oral fluid collected in a minimally invasive manner without use of sharps. Clinical Trials Registration. NCT02240875.


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