The role of Bordetella pertussis in the development of multiple sclerosis.

BACKGROUND: Multiple sclerosis (MS) is one of the most common neurological disorders which main cause is not identified yet. Some studies mentioned the possible role of infectious agents such as chlamydia pneumonia, mycoplasma and also, B. pertussis via asymptomatic nasopharyngeal colonization. The current study aimed to investigate and compared the serum level of B. pertussis antibody and the rate of nasopharyngeal colonization by this pathogen in subjects with and without MS. METHODS: In this case-control study, 109 patients with MS and 114 subjects without MS referred to Sina Hospital in Hamadan in 2019 are studied and compared in terms of serum titer of B. pertussis antibody and nasopharyngeal colonization by this bacterium. Colonization was evaluated using culture and real-time PCR techniques. Data were analyzed using SPSS version 16 with a 95% confidence interval. RESULTS: The serum titer of B. pertussis antibody in case and control groups was 37.8 and 35.1%, respectively (P = 0.74). Culture and real-time PCR techniques revealed no case of nasopharyngeal colonization by B. pertussis. CONCLUSION: There was no difference between B. pertussis antibody titer and the rate of nasopharyngeal colonization between both MS patients and the healthy control group. Therefore, it seems that probably B. pertussis has not a role in MS development.

Serum and salivary tissue transglutaminase IGA (tTG-IGA) level in celiac patients.

BACKGROUND: Celiac disease (CD) is a genetically determined autoimmune disease triggered by gluten consumption. Patients with these conditions have intraepithelial lymphocytosis, crypt hyperplasia, and severe intestinal atrophy. Gluten elimination is the only way to reduce this chronic inflammation. The diagnosis of CD is usually made by analyzing anti-tTG, anti-DGP, or EMA serological tests, and it is confirmed by biopsy of the duodenum. In people with CD, xerostomia or dry mouth is a common complication. This condition causes the salivary glands to malfunction and, in turn, may result in oral plaque and periodontal disease. By comparing salivary and serum levels of tissue transglutaminase IgA (tTG-IgA), this study aims to suggest a non-invasive method for diagnosis of CD. Furthermore, the present study evaluates the severity of xerostomia symptoms in people with CD. METHODS: In this case-control study, participants were patients referred to the internal ward of Sayyad Shirazi hospital. The control group was selected from healthy people who attended Gorgan Dental College. In this study, an analysis of serum was performed following consent from patients. This was followed by a salivary test, and the results of both tests were compared. The Xerostomia Inventory questionnaire was also used to determine the severity of xerostomia. As part of this study, examination of factors such as total protein concentration of saliva, albumin concentration, amylase level, pH, sodium, calcium, potassium, phosphorus, and interleukin (6, 18, and 21) were conducted. RESULTS: A total of 78 people were studied (aged 15 to 68), 26 were male (33.3%) and 52 were female (66.7%). In comparisons of the serum and saliva of people with and without CD, the level of amylase was higher in the latter group. The average levels of IL-6، IL-18 ،IL-21, and salivary and serum tTG were higher in people with CD. Additionally, CD patients were more likely to develop xerostomia. CONCLUSION: Study findings showed that CD can reduce certain salivary enzymes and elements, as well as increase inflammatory cytokines, salivary, and serum tTG. The management of dry mouth should also be recommended for celiac disease patients in order to prevent its complications.

Durability of Viral Neutralization in Asymptomatic Coronavirus Disease 2019 for at Least 60 Days.

A cohort consisting of asymptomatic healthcare workers donated temporal serum samples after infection with severe acute respiratory syndrome coronavirus 2. Analysis shows that all asymptomatic healthcare workers had neutralizing antibodies, that these antibodies persist for ≥60 days, and that anti-spike receptor-binding domain immunoglobulin G levels were correspondingly durable over the same time period.

Engineered NS1 for Sensitive, Specific Zika Virus Diagnosis from Patient Serology.

Dengue virus (DENV) and Zika virus (ZIKV) belong to the Flaviviridae family of viruses spread by Aedes aegypti mosquitoes in tropical and subtropical areas. Accurate diagnostic tests to differentiate the 2 infections are necessary for patient management and disease control. Using characterized ZIKV and DENV patient plasma in a blind manner, we validated an ELISA and a rapid immunochromatographic test for ZIKV detection. We engineered the ZIKV nonstructural protein 1 (NS1) for sensitive serologic detection with low cross reactivity against dengue and developed monoclonal antibodies specific for the ZIKV NS1 antigen. As expected, the serologic assays performed better with convalescent than acute plasma samples; the sensitivity ranged from 71% to 88%, depending on the performance of individual tests (IgM/IgG/NS1). Although serologic tests were generally less sensitive with acute samples, our ZIKV NS1 antibodies were able to complement the serologic tests to achieve greater sensitivity for detecting early infections.

Clinical testing for COVID-19.

As the novel coronavirus severe acute respiratory syndrome coronavirus 2 caused coronavirus disease 2019 cases in the United States, the initial test was developed and performed at the Centers for Disease Control and Prevention. As the number of cases increased, the demand for tests multiplied, leading the Centers for Disease Control and Prevention to use the Emergency Utilization Authorization to allow clinical and commercial laboratories to develop tests to detect the presence of the virus. Many nucleic acid tests based on RT-PCR were developed, each with different techniques, specifications, and turnaround time. As the illnesses turned into a pandemic, testing became more crucial. The test supply became inadequate to meet the need and so it had to be prioritized according to guidance. For surveillance, the need for serologic tests emerged. Here, we review the timeline of test development, the turnaround times, and the various approved tests, and compare them as regards the genes they detect. We concentrate on the point-of-care tests and discuss the basis for new serologic tests. We discuss the testing guidance for prioritization and their application in a hospital setting.

Chronic Human Pegivirus 2 without Hepatitis C Virus Co-infection.

Most human pegivirus 2 (HPgV-2) infections are associated with past or current hepatitis C virus (HCV) infection. HPgV-2 is thought to be a bloodborne virus: higher prevalence of active infection has been found in populations with a history of parenteral exposure to viruses. We evaluated longitudinally collected blood samples obtained from injection drug users (IDUs) for active and resolved HPgV-2 infections using a combination of HPgV-2-specific molecular and serologic tests. We found evidence of HPgV-2 infection in 11.2% (22/197) of past or current HCV-infected IDUs, compared with 1.9% (4/205) of an HCV-negative IDU population. Testing of available longitudinal blood samples from HPgV-2-positive participants identified 5 with chronic infection (>6 months viremia in >3 timepoints); 2 were identified among the HCV-positive IDUs and 3 among the HCV-negative IDUs. Our findings indicate that HPgV-2 can establish chronic infection and replicate in the absence of HCV.

Dengue Virus IgM Serotyping by ELISA with Recombinant Mutant Envelope Proteins.

We developed an IgM-based ELISA that identifies the dengue virus serotype of recent infections. Dominant serotypes were detectable in 91.1% of samples from travelers and 86.5% of samples from residents of endemic regions; 97.1% corresponded to the serotype identified by PCR. This ELISA enables more accurate reporting of epidemiologic findings.

Use of Urea Wash ELISA to Distinguish Zika and Dengue Virus Infections.

Serologic testing remains crucial for Zika virus diagnosis. We found that urea wash in a Zika virus nonstructural protein 1 IgG ELISA distinguishes secondary dengue virus infection from Zika virus infection with previous dengue (sensitivity 87.5%, specificity 93.8%). This test will aid serodiagnosis, serosurveillance, and monitoring of Zika complications in dengue-endemic regions.

Utility of dominant epitopes derived from cell-wall protein LppZ for immunodiagnostic of pulmonary tuberculosis.

BACKGROUND: Serological antibodies tests for tuberculosis (TB) are widely used in developing countries. They appear to have some advantages- faster, simple and could be used for extrapulmonary TB. However, most of current commercial TB serological tests are failed to provide sufficient sensitivity and specificity. Improved serological biomarkers were essential. In this study, we present an approach using peptide array to discover new immunodiagnostic biomarkers based on immunodominant epitopes of TB antigens. RESULTS: The Probable conserved lipoprotein LppZ, which is difficult to express and purify in vivo was selected as the model antigen. We use two-step screening for dominant epitope selection. Based on peptide array data from 170 TB patients and 41 control samples, two dominant epitopes were identified to have diagnostic value for TB patients. Truncation assay was used to identify the core reactive sequence. Peptide- based ELISA was used to evaluate the diagnostic ability of pep-LppZ-1 and pep-LppZ-13. Pep-LppZ-1 has a sensitivity of 49.2% and a specificity of 83.3% in TB diagnose. Pep-LppZ-13 has a sensitivity of 43.3% and a specificity of 88.5% in TB diagnose. CONCLUSIONS: Our result demonstrated that peptide array screening would be an advantage strategy of screening TB diagnostic peptides.

Incidence and risk factors for the prozone phenomenon in serologic testing for syphilis in a large cohort.

BACKGROUND: The prozone phenomenon is known to be associated with high antibody titers; other associations, such as host factors, have not been elucidated. METHODS: A retrospective analysis was conducted to evaluate the incidence of the prozone phenomenon of the syphilis rapid plasma reagin (RPR) test among 46 856 clinical samples, between June 2010 and June 2013. Logistic regression was used to analyze the risk factors of the prozone phenomenon. RESULTS: Our results showed that the incidence of the prozone phenomenon was low (0.83%) and could occur during any clinical phase, particularly during primary and secondary syphilis. Pregnancy and neurosyphilis were associated with the prozone phenomenon; sex, age, and whether the patient had been treated were not. The results also revealed that the prozone phenomenon not only occurred in patients with a high titer but also could occur in patients with a moderate/low titer. In fact, almost 31% of the patients with the prozone phenomenon had titers ≤1:16. CONCLUSIONS: The prozone phenomenon in the RPR test was associated with the phase of syphilis, pregnancy, and neurosyphilis as well as a range of RPR titers between 1:8 and 1:512. This latter finding is in contrast to previous reports that the prozone phenomenon is associated with very high RPR titers.

PCR combined with serologic testing improves the yield and efficiency of SARS-CoV-2 infection hunting: A study in 40,689 consecutive overseas arrivals.

Background: The global epidemiological situation of COVID-19 remains serious. The rapid hunting of SARS-CoV-2 infection is the key means for preventing transmission. Methods: A total of 40,689 consecutive overseas arrivals were screened for SARS-CoV-2 infection based on PCR and serologic testing. The yield and efficiency of different screening algorithms were evaluated. Result: Among the 40,689 consecutive overseas arrivals, 56 (0.14%) subjects were confirmed to have SARS-CoV-2 infection. The asymptomatic rate was 76.8%. When the algorithm based on PCR alone was used, the identification yield of a single round of PCR (PCR1) was only 39.3% (95% CI: 26.1-52.5%). It took at least four rounds of PCR to achieve a yield of 92.9% (95% CI: 85.9-99.8%). Fortunately, an algorithm based on a single round of PCR combined with a single round of serologic testing (PCR1+ Ab1) greatly improved the screening yield to 98.2% (95% CI: 94.6-100.0%) and required 42,299 PCR and 40,689 serologic tests that cost 6,052,855 yuan. By achieving a similar yield, the cost of PCR1+ Ab1 was 39.2% of that of four rounds of PCR. For hunting one case in PCR1+ Ab1, 769 PCR and 740 serologic tests were required, costing 110,052 yuan, which was 63.0% of that of the PCR1 algorithm. Conclusion: Comparing an algorithm based on PCR alone, PCR combined with a serologic testing algorithm greatly improved the yield and efficiency of the identification of SARS-CoV-2 infection.

Advantages and limitations of current diagnostic laboratory approaches in syphilis and congenital syphilis.

INTRODUCTION: The reemergence of syphilis, especially congenital syphilis, presents a significant public health threat. Accurate diagnosis of syphilis depends on recognition of a constellation of symptoms, review of medical and sexual history, and multiple laboratory tests. While reliable, current tests for syphilis can be difficult to interpret, which can lead to delays in treatment. AREA COVERED: This review summarizes the major advantages and limitations of available diagnostic laboratory methods for syphilis, provides an update on recent advances in laboratory tools, and highlights the urgent need for coordinated efforts to create new tools to halt the resurgence of syphilis. EXPERT OPINION: In syphilis, the wide variety of short-lived signs and symptoms followed by periods of latency create diagnostic challenges. Currently available laboratory tests, when positive, require additional information to interpret (prior testing, treatment, and sexual history). Point-of-care tests that can rapidly and accurately detect both treponemal and non-treponemal antibodies would be a huge step toward reducing test turnaround time and time to treatment. Incorporating biological insights and technology innovations to advance the development of direct detection assays is urgently needed. A comprehensive coordinated effort is critical to stem the tide of rising syphilis in the United States and globally.

Syphilis-related Membranous Nephropathy in a 35-year-old Woman.

A 35-year-old woman was admitted for the examination of lower leg edema and proteinuria. A kidney biopsy showed membranous nephropathy (MN) with fine granular deposits of IgG along the glomerular capillary and poor spike formation, differing from primary MN in the presence of positive IgG3 and C1q. Lupus nephritis was excluded because serum complement and anti-dsDNA antibody, anti-Smith antibody, and anti-cardiolipin antibody tests were negative. The serological test for syphilis was positive, as was the Treponema pallidum hemagglutination test. The patient was diagnosed with syphilis, and the proteinuria disappeared with antibiotic treatment. In MN with positive IgG3 and C1q, syphilis nephropathy may be a differential diagnosis.

Antibody Response to SARS-CoV-2 in the First Batch of COVID-19 Patients in China by a Self-Developed Rapid IgM-IgG Test.

It has been over two years since the COVID-19 pandemic began and it is still an unprecedented global challenge. Here, we aim to characterize the antibody profile from a large batch of early COVID-19 cases in China, from January - March 2020. More than 1,000 serum samples from participants in Hubei and Zhejiang province were collected. A series of serum samples were also collected along the disease course from 70 patients in Shanghai and Chongqing for longitudinal analysis. The serologic assay (ALLtest) we developed was confirmed to have high sensitivity (92.58% - 97.55%) and high specificity (92.14% - 96.28%) for the detection of SARS-CoV-2 nucleocapsid-specific antibodies. Confirmed cases found in the Hubei Provincial Center for Disease Control and Prevention (HBCDC), showed a significantly (p = 0.0018) higher positive rate from the ALLtest than RNA test. Then, we further identified the disease course, age, sex, and symptoms that were correlating factors with our ALLtest results. In summary, we confirmed the high reliability of our ALLtest and its important role in COVID-19 diagnosis. The correlating factors we identified will require special attention during future clinical application.

Severe Acute Respiratory Syndrome Coronavirus 2 Diagnostic Tests for Border Screening During the Very Early Phase of Coronavirus Disease 2019 Pandemic: A Systematic Review and Meta-Analysis.

Diagnosis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) during border screening among returning residents and prioritized travelers during the early phase of a pandemic can reduce the risk of importation and transmission in the community. This study aimed to compare the accuracy of various SARS-CoV-2 diagnostics and assess their potential utility as border screening for infection and immunity. Systematic literature searches were conducted in six electronic databases for studies reporting SARS-CoV-2 diagnostics (up to April 30, 2020). Meta-analysis and methodological assessment were conducted for all included studies. The performance of the diagnostic tests was evaluated with pooled sensitivity, specificity, and their respective 95% confidence intervals. A total of 5,416 unique studies were identified and 95 studies (at least 29,785 patients/samples) were included. Nucleic acid amplification tests (NAAT) consistently outperformed all other diagnostic methods regardless of the selected viral genes with a pooled sensitivity of 98% and a pooled specificity of 99%. Point-of-care (POC) serology tests had moderately high pooled sensitivity (69%), albeit lower than laboratory-based serology tests (89%), but both had high pooled specificity (96-98%). Serology tests were more sensitive for sampling collected at ≥ 7 days than ≤ 7 days from the disease symptoms onset. POC NAAT and POC serology tests are suitable for detecting infection and immunity against the virus, respectively as border screening. Independent validation in each country is highly encouraged with the preferred choice of diagnostic tool/s.

Clinical Application of Serologic Testing for Coronavirus Disease 2019 in Contemporary Cardiovascular Practice.

In patients with cardiovascular disease, the use of antibody or serological testing is frequently encountered as the coronavirus disease 2019 pandemic continues to evolve. Antibody testing detects one form of the acquired immunological response to a pathogenic antigen. Once the immune system recognizes a viral antigen or a protein as foreign, a humoral immune response is initiated, which is generally detected by laboratory testing in 5 to 10 days after the initial exposure. While this information is critical from a public health perspective to implement surveillance systems and measures to limit infectivity and transmission rate, the misinterpretation of serologic testing in clinical practice has generated much confusion in the medical community because some attempted to apply these strategies to individual patient's treatment schemes. In this mini-review, we examine the different serologic-based testing strategies, how to interpret their results, and their public health impact at the population level, which are critical to contain the transmission of the virus in the community within a busy cardiovascular practice. Further, this review will also be particularly helpful as vaccination and immune therapy for coronavirus disease 2019 become available to the society as a whole.

Noninvasive measure of treatment response in non-alcoholic steatohepatitis: Insights from EMMINENCE and meta-analysis.

BACKGROUND AND AIM: Liver histology changes are the current gold standard for evaluating non-alcoholic steatohepatitis (NASH), but are limited by their invasiveness and variability for sampling and interpretation. We evaluated noninvasive biomarkers as an indication of histologic changes in NASH. METHODS: Associations between 12-month biomarker and NASH Clinical Research Network histologic score changes in 339 patients with NASH in the EMMINENCE trial was examined with multivariable models and partial canonical correlation. A meta-analysis of 17 NASH trials including 3717 patients examined associations between these same changes and histologic response within treatment groups, and treatment effects on biomarkers and on liver histology. Biopsy measures assessed were changes in ballooning, steatosis, inflammation, and fibrosis, NASH improvement without worsening of fibrosis, and fibrosis improvement without worsening of NASH. All analytic methods suggest that a combination of aspartate aminotransferase (AST), cytokeratin-18 (CK-18 [M30 or M65]), and hemoglobin A1C (HbA1c) changes best predicts overall liver biopsy changes in response to interventions. RESULTS: The weighted average of standardized mean changes (0.403 × AST, 0.314 × CK-18, 0.283 × HbA1c) facilitated comparisons of within-group responses and treatment effects among studies included in the meta-analysis. This composite in EMMINENCE discriminated between patients with and without NASH resolution without worsening fibrosis with area under the receiver-operator characteristic curve of 0.7880, and for fibrosis improvement without NASH worsening of 0.7553. CONCLUSION: A composite score based on changes in AST, HbA1c, and CK-18 could serve as a surrogate for liver histologic improvement and an effective objective, noninvasive tool for comparative assessment of treatment effects of novel interventions.

Factors for Negative Result in Serum Anti-Helicobacter pylori IgG Antibody Test in Adult Subjects With Nodular Gastritis: A Single-center Study.

AIM: Nodular gastritis has been demonstrated to be strongly associated with Helicobacter pylori infection. The present retrospective study was performed to elucidate factors related to a negative serum antibody test result in adults with nodular gastritis. MATERIALS AND METHODS: We investigated 116 H. pylori-positive subjects endoscopically diagnosed with nodular gastritis and subjected to a serum anti-H. pylori immunoglobulin G (IgG) antibody test. The degree of gastric mucosal atrophy and the presence of spotty redness in the gastric body and fornix were carefully determined by observations of endoscopic images. RESULTS: Of the 116 investigated subjects, 108 were positive and 8 negative in serum anti-H. pylori IgG antibody test results. The degree of gastric mucosal atrophy was mild in seven among eight seronegative cases. The levels of pepsinogen II in serum in patients with negative antibody test findings were significantly lower as compared to those found positive, while the pepsinogen I/II ratio tended to be higher in subjects shown negative by the test. Only 1 of 69 with spotty redness was negative in serum anti-H. pylori IgG antibody testing, while 7 of 47 without spotty redness were negative. Multiple logistic regression analysis of subjects with a negative test result revealed that the absence of spotty redness shown by endoscopy was a significant risk factor. CONCLUSION: The absence of spotty redness, which may reflect the degree of gastric body inflammation, is a significant factor indicating increased risk for a negative serum anti-H. pylori IgG antibody test result in subjects with nodular gastritis.

Review of Current COVID-19 Diagnostics and Opportunities for Further Development.

Diagnostic testing plays a critical role in addressing the coronavirus disease 2019 (COVID-19) pandemic, caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). Rapid and accurate diagnostic tests are imperative for identifying and managing infected individuals, contact tracing, epidemiologic characterization, and public health decision making. Laboratory testing may be performed based on symptomatic presentation or for screening of asymptomatic people. Confirmation of SARS-CoV-2 infection is typically by nucleic acid amplification tests (NAAT), which requires specialized equipment and training and may be particularly challenging in resource-limited settings. NAAT may give false-negative results due to timing of sample collection relative to infection, improper sampling of respiratory specimens, inadequate preservation of samples, and technical limitations; false-positives may occur due to technical errors, particularly contamination during the manual real-time polymerase chain reaction (RT-PCR) process. Thus, clinical presentation, contact history and contemporary phyloepidemiology must be considered when interpreting results. Several sample-to-answer platforms, including high-throughput systems and Point of Care (PoC) assays, have been developed to increase testing capacity and decrease technical errors. Alternatives to RT-PCR assay, such as other RNA detection methods and antigen tests may be appropriate for certain situations, such as resource-limited settings. While sequencing is important to monitor on-going evolution of the SARS-CoV-2 genome, antibody assays are useful for epidemiologic purposes. The ever-expanding assortment of tests, with varying clinical utility, performance requirements, and limitations, merits comparative evaluation. We herein provide a comprehensive review of currently available COVID-19 diagnostics, exploring their pros and cons as well as appropriate indications. Strategies to further optimize safety, speed, and ease of SARS-CoV-2 testing without compromising accuracy are suggested. Access to scalable diagnostic tools and continued technologic advances, including machine learning and smartphone integration, will facilitate control of the current pandemic as well as preparedness for the next one.

Diagnosis of COVID-19 in Patients with Negative Nasopharyngeal Swabs: Reliability of Radiological and Clinical Diagnosis and Accuracy Versus Serology.

BACKGROUND: The diagnosis of Coronavirus disease 2019 (COVID-19) relies on the positivity of nasopharyngeal swab. However, a significant percentage of symptomatic patients may test negative. We evaluated the reliability of COVID-19 diagnosis made by radiologists and clinicians and its accuracy versus serology in a sample of patients hospitalized for suspected COVID-19 with multiple negative swabs. METHODS: Admission chest CT-scans and clinical records of swab-negative patients, treated according to the COVID-19 protocol or deceased during hospitalization, were retrospectively evaluated by two radiologists and two clinicians, respectively. RESULTS: Of 254 patients, 169 swab-confirmed cases and one patient without chest CT-scan were excluded. A total of 84 patients were eligible for the reliability study. Of these, 21 patients died during hospitalization; the remaining 63 underwent serological testing and were eligible for the accuracy evaluation. Of the 63, 26 patients showed anti-Sars-Cov-2 antibodies, while 37 did not. The inter-rater agreement was "substantial" (kappa 0.683) between radiologists, "moderate" (kappa 0.454) between clinicians, and only "fair" (kappa 0.341) between radiologists and clinicians. Both radiologic and clinical evaluations showed good accuracy compared to serology. CONCLUSIONS: The radiologic and clinical diagnosis of COVID-19 for swab-negative patients proved to be sufficiently reliable and accurate to allow a diagnosis of COVID-19, which needs to be confirmed by serology and follow-up.