Effect of storage temperatures simulating transport conditions of nasopharyngeal swabs on the results of a chemiluminescence immunoassay (CLIA) to detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antigen.

PURPOSE: Chemiluminescence Immunoassay (CLIA) is high throughput, rapid diagnostic test which has recently come up for the detection of SARS-CoV-2 antigen. The present study evaluated performance of CLIA antigen test in nasopharyngeal swab samples stored at different temperatures for 7 days to simulate the transport conditions and transit time across the country from remote peripheral laboratories to central facilities. MATERIALS AND METHODS: Limit of detection (LOD), sensitivity and specificity of VITROS® SARS-CoV-2 antigen assay was determined using Real-time reverse transcriptase PCR (rRT-PCR) confirmed SARS-CoV-2 positive and negative samples. To detect the effect of storage temperatures on VITROS ®SARS-CoV-2 antigen results, samples were stored at 4 â€‹°C, 25 â€‹°C & 37 â€‹°C for 7 days followed by detection of SARS-CoV-2 nucleocapsid antigen and compared with N-gene rRT-PCR. RESULTS: The VITROS® SARS-CoV-2 antigen test was found to have a sensitivity and specificity of 78.9% and 100% respectively with high sensitivity of 88.1% for samples with Ct â€‹< â€‹30. The LOD of VITROS assay was equivalent to 3800 copies of RNA per reactions as compared to 72 copies per reaction for rRT-PCR. We observed that more than 80% of samples with <30 Ct values could be detected by VITROS SARS-CoV-2 antigen assay at day 7 even when stored at 37 â€‹°C. For samples with Ct values between 26 and 30, on day 7 the positivity rate of N-antigen at 4 â€‹°C was 90.9% and 37 â€‹°C was 63.6%. CONCLUSIONS: CLIA testing can be carried out for the detection of SARS-CoV-2 N-protein in NP-swab samples transported in cold chain even with 7 days transit time, particularly for Ct â€‹< â€‹30 samples which represents cases with higher transmissibility. As drop in positivity for VITROS assay was lower as compared to rRT-PCR on day 7 in cold chain-maintained samples, the assay can be useful to screen samples received from remote peripheral areas before performing rRT-PCR.

Differential expression of circulating microRNAs in serum: Potential biomarkers to track Japanese encephalitis virus infection.

Japanese encephalitis is one of the serious vector-borne viral encephalitis diseases found worldwide and poses a major threat to public health. Most Japanese encephalitis virus (JEV) infections are subclinical; only 1: 250 to 1:1000 infected persons develop clinical presentations. Delay in proper diagnosis of JE affects the timeliness of treatment initiation and increases the mortality rate in patients. Therefore, there is an extreme need to develop potential biomarkers, which might improve the diagnosis and can become the basis for development of new therapeutics. The microRNAs (miRNAs/or miRs) are small noncoding RNAs of 17-24 nucleotides that are known to regulate about 60% of human genes. Although miRNAs have been found to regulate various aspects of innate and adaptive immune responses, less information on circulating miRNAs in JE is known. The study of JEV infected human serum miRNAs will provide novel information for the diagnosis of JE as well as for the improvement of disease outcome. Total RNA, including miRNA, was extracted from serum followed by the complementary DNA (cDNA) synthesis by using sequence-specific primers. cDNA was amplified using target-specific TaqMan MicroRNA Assay. Real-time polymerase chain reaction data was normalized using both exogenous (cel-miR-39) and endogenous (hsa-miR-93) controls. We have found significantly altered expression of miR-155 and miR-21 in serum of JEV infected patients as compared to healthy controls, revealing their role as a a noninvasive biomarker in JE. A significant correlation between miRNAs and JE was observed that offers the basis for miRNAs to serve as a new component to develop possible therapeutic strategies for JE in near future.

Association of interleukin-6 (174 G/C) and interleukin-12B (1188 A/C) gene polymorphism with expression and risk of Japanese encephalitis disease in North Indian population.

BACKGROUND: Japanese encephalitis is an acute inflammatory disease caused by Japanese encephalitis virus (JEV). In this study we aim to determine the association of IL-6 (174) and IL-12B (1188A/C) gene polymorphisms with JEV susceptibility, disease severity and outcomes in north Indian population. METHODS: This study was performed an equal number of cases and control individuals (125). Gene polymorphism has been analyzed by PCR-RFLP and expression by ELISA. RESULTS: Homozygous(C/C) genotypes of IL-12B were significantly associated with protection in JE infection (p = 0.008, OR = 0.368) whereas IL-6 was not associated with JEV infection (p = 0.269, OR = 1.245). The C allele of IL-6 was associated with protection in JE disease and G/C genotype was associated with outcomes with recovered individuals. CONCLUSION: IL-12B gene polymorphism leads to increase level of IL-12B in JE patients, which can contribute to JE susceptibility and disease severity. IL-6 polymorphism has not been associated with susceptibility of JE. Overall, this is the first information from northern India shows association of IL-6 and IL-12B polymorphisms with JE disease.

Increased serum microRNA-29b expression and bad recovery in Japanese encephalitis virus infected patients; A new component to improve the disease recovery.

BACKGROUND: Japanese encephalitis virus (JEV) is a neurotropic mosquito-borne Flavivirus, mainly prevalent in Asia. It is the most important causative agent of acute viral encephalitis in humans. Recently, micro RNAs are discovered as a key regulator of inflammatory and immune responses in various diseases including neurological and viral infections. Thus, this study was proposed to check whether changes in cellular miRNA expression due to JE virus infection, can be detected in circulation which would be helpful in diagnosis and treatment. METHODS: miRNAs (miR-29b and miR-146a) were analyzed in the serum of JEV infected patients using quantitative reverse transcription polymerase chain reaction (RT-qPCR). RESULTS: miR-146a was found significantly decreased (p = 0.0008) in JEV infected patients as compared to healthy controls whereas miR-29b was significantly increased (p = 0.001) in JEV patients recovered with neurological sequelae when compared to those recovered without sequelae. CONCLUSION: In conclusion, miRNA can be measured in serum. Studying microRNAs will provide novel information and help us to identify the components that can serve as biomarkers and can lead to new discovery in controlling disease recovery.

Association of ICAM-1 (K469E) and MCP-1-2518 A > G polymorphism with risk of Japanese encephalitis in North Indian population.

BACKGROUND: Japanese encephalitis virus (JEV) is most important cause of viral encephalitis worldwide. The pathogenesis of this is probably attributed to the host genetic makeup. Intercellular adhesion molecule-1 (ICAM-1) and monocytes chemoattractant protein-1 (MCP-1) play a vital role in host defense mechanism against flavivirus causing encephalitis. We assessed the possible genetic association between ICAM-1 (K469E) and MCP-1-2518 A > G polymorphisms and Japanese Encephalitis in North Indian population. METHODS: We studied ICAM-1(K469E) and MCP-1-2518 A > G polymorphisms with the help of polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis. Expression of ICAM-1 and MCP-1 were determined at mRNA and protein levels in JE patients and healthy controls by real-time polymerase chain reaction and enzyme-linked immunosorbent assay (ELISA). RESULTS: Homozygous (E/E) genotype of ICAM-1 was associated with clinical severity (p = 0.015) and outcome (p = 0.04) of JE, whereas, heterozygous (A/G) genotype of MCP-1-2518 A > G was associated with outcome in JE patients (p = 0.01). Among severe cases of JE, a higher level of ICAM-1 was observed in patients with E allele (E/K + E/E) of ICAM-1 (K469E) than non-E allele (K/K). The level of MCP-1 was found significantly increased in JE patients with homozygous (G/G) genotype when compared to wild (A/A) genotype of MCP-1-2518 A > G (p = 0.03). CONCLUSION: ICAM-1 (K469E) and MCP-1-2518 A > G polymorphisms lead to increased level of ICAM-1 and MCP-1 in Japanese Encephalitis which may be associated with severity as well as an adverse outcome of the disease. ICAM-1 (K469E) polymorphism may affect host susceptibility to Japanese encephalitis in North Indian population.

Cytomegalovirus infection in pregnant women and its association with bad obstetric outcomes in Northern India.

BACKGROUND: Cytomegalovirus (CMV) infection during pregnancy is far more complex than other infections, due to ability of the virus to be frequently reactivated during the child bearing age and may vertically transmitted to the developing fetus in spite of maternal immunity. Therefore, in the current study we determined the prevalence of CMV infection in pregnant women and tried to identify the role of maternal CMV infection in adverse pregnancy outcomes in Northern India. In this case-control study, 517 pregnant women, out of them 200 in case group and 317 in the control group. The overall 31.72% (164/517) cases were found with active CMV infection. CMV positivity (p=0.026) was significantly associated with bad obstetric history (75/200, 37.50%) compared to normal pregnancy (89/317, 28.07%). CMV infection was predominantly observed in age group 21-25 years. CMV positivity have been found to be significantly higher in women from rural area as compare to those from urban area (p=0.028). However, no significant difference has been observed in case of occupation, income, and haemoglobin level.

Detection of long term cellular immune response to Japanese encephalitis vaccination using IFN-γ ELIspot assay.

Vaccine is the most effective preventive measure against Japanese Encephalitis infection. Role of IFN-γ expressing T cells for JE virus clearance has been described as a part of cellular immunity. Vaccine induced immunity also involve the cellular immune response, therefore the study was aimed to observe induction and persistence of IFN-γ expressing T cells by IFN-γ ELISpot assay. The cell count increased significantly after 28 (P < 0.0001) days post vaccination, and remained higher at all time points (day 28, day 180, day 360) when compared with prevaccination. This study will be helpful for designing future vaccination strategy and improving vaccine efficacy.

An outbreak of encephalitis associated with echovirus 19 in Uttar Pradesh, India, in 2011.

A sequence-independent single-primer amplification method and a modified enterovirus VP1 gene typing primer were used for identification of echovirus 19 and enterovirus 101, which remained undiagnosed by standard enterovirus molecular typing methods. Six different serotypes were identified during this study, with the predominance of ECV 19 (n = 20) followed by echovirus 21 (n = 3), EV 69 and EV 101 (n = 2 each), coxsackievirus B5 and ECV 27 (n = 1 each). To our knowledge, this is the first report of enteroviruses 69 and 101 in encephalitis cases in India.