IgM Antibodies In Serum Samples Research Articles

Seroprevalence of SARS-Cov-2 Virus Infection In Kermanshah, Iran: A Population-based Cross-Sectional Study

Background: The aim of this study was to estimate the seroprevalence of SARS-CoV-2 infection in a general population from Kermanshah province, Iran. Methods: The present study was a population-based cross-sectional design conducted in Kermanshah province in 2020. Sampling was performed in a multi-stage process, and 1967 participants were considered, and also 174 interviewers were assigned to collect data online. Then, 5 mL of blood sample was taken from every participant. The blood samples were centrifuged with the ELISA method to detect SARS-CoV-2-specific IgG and IgM antibodies in serum samples. Seropositive prevalence was adjusted by means of survey analysis. Case fatality rate (CFR) and infection fatality rate (IFR) were estimated. Results: A total of 1967 people from 14 cities of the province participated in the study. The mean age of participants was 35.7±16.9, and 50.4% were female. The lowest and highest seroprevalence was found in the cities of Paveh (2.3% [0.3- 4.2]) and Harsin (61.6% [54.7–68.5]), respectively. The CFR and IFR in men and women were 3.4 vs. 3.3 and 0.1 vs. 0.3. The aged 60 years or older had the highest CFR and IFR with 11.2 and 3.7%, respectively. Conclusion: The prevalence of SARS-CoV-2 infection and IFR among the general population of Kermanshah province was 18.3 and 0.3%, respectively. The results of this study can assist the policymaker in assessing risk factors, and transmission dynamics of SARS-CoV-2 in a population and implementing preventive and control interventions.

Seroprevalence of SARS-Cov-2 Virus Infection In Kermanshah, Iran: A Population-based Cross-Sectional Study

Background: The aim of this study was to estimate the seroprevalence of SARS-CoV-2 infection in a general population from Kermanshah province, Iran. Methods: The present study was a population-based cross-sectional design conducted in Kermanshah province in 2020. Sampling was performed in a multi-stage process, and 1967 participants were considered, and also 174 interviewers were assigned to collect data online. Then, 5 mL of blood sample was taken from every participant. The blood samples were centrifuged with the ELISA method to detect SARS-CoV-2-specific IgG and IgM antibodies in serum samples. Seropositive prevalence was adjusted by means of survey analysis. Case fatality rate (CFR) and infection fatality rate (IFR) were estimated. Results: A total of 1967 people from 14 cities of the province participated in the study. The mean age of participants was 35.7±16.9, and 50.4% were female. The lowest and highest seroprevalence was found in the cities of Paveh (2.3% [0.3- 4.2]) and Harsin (61.6% [54.7–68.5]), respectively. The CFR and IFR in men and women were 3.4 vs. 3.3 and 0.1 vs. 0.3. The aged 60 years or older had the highest CFR and IFR with 11.2 and 3.7%, respectively. Conclusion: The prevalence of SARS-CoV-2 infection and IFR among the general population of Kermanshah province was 18.3 and 0.3%, respectively. The results of this study can assist the policymaker in assessing risk factors, and transmission dynamics of SARS-CoV-2 in a population and implementing preventive and control interventions.

The Association of Cytomegalovirus IgM and Allostatic Load.

Background: Cytomegalovirus (CMV) is a deoxyribonucleic acid virus that affects a significant proportion of the worldwide population; after primary infection, it goes into a latent state and can be reactivated, primarily after a reduction in host immune defenses. Methods: This study evaluated the association of acute cytomegalovirus infection (CMV IgM) and Allostatic Load (AL) by sociodemographic factors using data from the National Health and Nutrition Examination Survey (NHANES) 2001–2004 among participants (aged 20–49 years). CMV infection was determined by the level of CMV IgM antibody in serum samples. AL was assessed as a combination of 10 biomarkers from the cardiovascular, inflammatory, and metabolic systems. The evaluation of the association between CMV infection and AL included descriptive statistics and logistic regression models, which were adjusted for demographic and behavioral covariates. Results: AL was more elevated among those who were older, male, those with lower education, those performing limited physical activity, and smokers. CMV was more elevated in females than males among those who consumed alcohol and cigarette smokers. In Pearson’s correlation analysis, there was a slight positive correlation between CMV IgM and AL, with triglycerides and Body Mass Index (BMI) the most strongly correlated with AL. Binary logistic regression showed no significant relationship between high AL and positive CMV IgM but did show a significant relationship between high AL and age (OR = 1.0592, 95% CI 1.0215–1.0983, p = 0.00715). The findings of this study provide insight into the relationship between CMV and AL and provide awareness of factors that affect their relationship.

Detection of Epithelial Giant Cells in Nasal Aspirate Cytological Smears Using Deep Learning and Computer Vision Techniques: an Approach for Early Diagnosis of Measles Disease

Measles disease is usually diagnosed through an RT-PCR test, which detects the measles-specific IgM antibody in serum samples. However, this approach is highly expensive and requires a lot of sample preprocessing making it a laborious task. Another approach for measles identification could be a cytological smear test – which is a low-cost, quick, and accurate method for the early detection of measles disease. Due to the lack of experience in interpreting smears, its usage in clinical practice is currently limited. We have designed a MesoSpot, an automatic segmentation method for the first time that can precisely define the region of giant cells in nasal aspirate cytological smears and assist medical experts in the speedy diagnosis of measles disease. MesoSpot was developed by training 500 cytological smear images collected from various web sources. We have used 50 cytological smear images to validate the model and evaluated its performance using various metrics. The main purpose of the proposed study is to detect multinucleated giant cells and estimate their size and number, which aids in assessing the disease's severity. To annotate the giant cells in each cytological smear, we have applied a semantic segmentation approach using APEER software. UNET architecture was used to train the model, and image processing techniques were used to spot giant cells and predict their size. Various performance metrics were employed to assess the model's efficiency. The model's output was also compared to the ground truth image and statistically confirmed.

Toxoplasma gondii and Neospora caninum Infections in Stray Cats and Dogs in the Qinghai-Tibetan Plateau Area, China.

Simple SummaryDiseases caused by parasites have introduced serious threats to human health and the development of animal husbandry in the Qinghai–Tibetan Plateau Area (QTPA), such as toxoplasmosis caused by Toxoplasma gondii and neosporosis caused by Neospora caninum. However, information on the epidemiology of toxoplasmosis and neosporosis in stray cats and dogs which are the definitive hosts of T. gondii and N. caninum in the QTPA is limited. The aim of this study was to establish a detailed record of the seroprevalence of T. gondii and N. caninum-specific IgG and IgM antibodies in serum samples and the molecular epidemiology in feces from stray cats and dogs in the plateau area. The results revealed that stray cats and dogs in the QTPA, China present both T. gondii and N. caninum infection through the antibodies and antigen detection of the indirect ELISA tests and qPCRs. The present study suggests the prevalence of acute neosporosis and chronic re-emergence of toxoplasmosis in stray cats and dogs in the testing area. To the best of our knowledge, this is the first report of T. gondii and N. caninum infection in cats and dogs in the QTPA, and the first determination of N. caninum infection in cats in China. In conclusion, stray cats and dogs play key roles in the transmission and prevalence of T. gondii and N. caninum in the plateau area.Toxoplasma gondii and Neospora caninum belong to the Apicomplexan protozoa which is an obligate intracellular parasite, causing toxoplasmosis and neosporosis throughout the world. Cats and dogs are the definitive hosts of these two parasites. However, information on the epidemiology of toxoplasmosis and neosporosis in stray cats and dogs in the Qinghai–Tibetan Plateau Area (QTPA) is limited, and little is known about the diversity of the diseases. Therefore, the aim of this study was to perform indirect ELISA tests based on recombinant TgSAG1, TgGRA1, NcSAG1 and NcGRA7 proteins to establish a detailed record of the seroprevalence of T. gondii and N. caninum-specific IgG and IgM antibodies in serum samples and to develop qPCR amplification based on TgB1 and NcNc5 genes to conduct molecular epidemiology in feces from stray cats and dogs in the QTPA. In the current study, a total of 128 cat serum samples were analyzed through serological tests in which 53 (41.4%) and 57 (44.5%) samples were found positive for T. gondii specific-IgG and IgM antibodies, and 2 (1.6%) and 74 (57.8%) samples were confirmed positive for N. caninum specific-IgG and IgM antibodies, respectively. Out of 224 stray dog sera, 59.8% and 58.9% were recorded as positive against anti-Toxoplasma IgG and IgM antibodies, 17.9% and 64.7% were detected positive against Neospora IgG and IgM. On the other hand, 1 of 18 cat fecal samples was successfully amplified within the Ct value of 10 to 30 while no cat was positive for neosporosis. Moreover, a higher prevalence of toxoplasmosis in stray dogs (14.5%, 16/110) than of neosporosis (5.5%, 6/110) with different parasite numbers were found. Further analysis showed that no significant sex differences were found nor between the overall infection rates of T. gondii and N. caninum in this study. This study suggests that stray cats and dogs play key roles in the transmission and prevalence of T. gondii and N. caninum in the plateau area.

Detection of Anti-Leptospira IgM Antibody in Serum Samples of Suspected Patients Visiting National Public Health Laboratory, Teku, Kathmandu.

Leptospirosis is a globally distributed zoonosis with varied clinical outcomes and multiorgan involvement in humans. In this study conducted from July 2011 to December 2011, 178 serum samples from patients suspected of leptospirosis were tested by Panbio IgM ELISA at National Public Health Laboratory, Kathmandu, out of which 51 (28.65%) were positive for anti-Leptospira IgM antibody. Leptospirosis was more common in people in their 2nd and 3rd decades of their life which together comprised 56.86% of the total positive cases. Most of those tested positive were farmers followed by students and housewives. Both animal contact and water contact seemed to play significant roles in disease transmission. Symptoms were vague with the most common being fever, headache, myalgia, abdominal pain, vomiting, jaundice, and diarrhoea. Life style heavily dominated by agronomical and farming activities in Nepal is conducive to leptospirosis transmission. Leptospirosis seems to be a significant public health problem in Nepal but is underestimated. In resource poor countries like Nepal where laboratories performing MAT or maintaining cultures are rarely available, serological test like ELISA could well depict the scenario of the disease prevalence.

Outbreak of chickenpox in a Union Territory of North India

Purpose: Primary infection with a varicella-zoster virus (VZV) leads to chickenpox. Though the incidence of the disease has decreased in many developed countries due to the introduction of the varicella vaccine, outbreaks continue to occur in developing countries. Materials and Methods: The present study reports an outbreak of varicella in an urbanised village in the vicinity of Chandigarh City in North India in November 2013. The outbreak was confirmed by the detection of VZV IgM antibodies in serum samples of clinically suspected patients. Vesicular fluid samples were collected from 8 patients with active lesions and tested for VZV DNA by polymerase chain reaction. Blood samples were also collected from 17 healthy controls residing in the same locality and tested for the presence of VZV IgM and IgG antibodies. Results: A total of 18 cases occurred, and the majority of them (67%) were <15 years of age. Of 17 samples collected from patients with the clinically suspected disease, 13 (76.5%) showed the presence of VZV IgM antibodies. Of the healthy controls, 6 were VZV IgM positive and 4 of them developed symptomatic disease on follow-up. VZV DNA was positive in 5/8 (62.5%) of the patients. In one patient, VZV DNA was detected in the absence of an IgM antibody response. Conclusion: The introduction of varicella vaccine in the universal immunisation programme of India may help to prevent these outbreaks; however, the cost-benefit analysis needs to be carried out before making such policies.

ANTI- ANNEXIN 1 ANTIBODIES CORRELATION BETWEEN ANTIBODIES LEVEL AND DISEASE ACTIVITY IN SOME AUTOIMMUNE CONNECTIVE TISSUE DISEASES

Annexin 1 is an anti-inflammatory protein, exerts a regulatory effect in both innate and adaptive immune responses. Autoantibodies against annexin 1 have been recognized in some patients with autoimmune connective tissue diseases. Aim: to detect presence of anti-annexin 1 antibodies in patients with rheumatoid arthritis, scleroderma, systemic and discoid lupus erythematosus and to evaluate whether there is a correlation between the antibodies levels and disease activity. Methods: determining the levels of IgM antibodies in serum samples by ELISA and correlating them with the disease activity, which is evaluated using specific activity index for each disease. Results: levels of anti- annexin 1 antibodies were found to be significantly higher in diseased groups when compared to normal healthy controls. When correlating antibodies levels with disease activity, rheumatoid arthritis and discoid lupus patients showed no significant correlation, however systemic lupus and scleroderma patients showed significant correlation between antibodies levels and disease activity. Conclusion: anti- annexin 1 antibodies might be a promising aid in diagnosis of these diseases and could have a prognostic capacity in some autoimmune connective tissue diseases. Key words: Annexin 1- autoantibodies- autoimmune connective tissue diseases.

Expression of enterovirus 71 capsid protein VP1 in Escherichia coli and its clinical application

The VPl gene of enterovirus 71 (EV71) was synthesized, construct a recombinant plasmid pET15b/VP1 and expressed in E. coli BL21. The recombinant VP1 protein could specifically react with EV71-infected patient sera without the cross-reaction with serum antibodies of coxsackievirus A16 (CA16), A4, A5, B3 and B5 as well as echovirus 6. In acute and convalescent phases, IgM and IgG antibodies of 182 serum samples were detected by ELISA with recombinant VP1 protein as a coated antigen. The results showed that the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of IgM antibodies in serum samples for the diagnosis of EV71 infection were 90.1, 98.4, 98.8 and 88.7%, respectively; similarly, those of IgG antibodies in serum samples were 82.4, 89.1, 91.5 and 78.1%, respectively. Five of 80 samples (6.25%) from CA16-infected patients were detected positive by ELISA with recombinant VP1 protein in which indicated the cross reactions and 0 of 5 samples from patients infected with other enteroviruses including CA4, CA5, CB3, CB5 and echovirus 6. Therefore, the recombinant VP1 protein of EV7l may provide a theoretical reference for establishing an effective antibody screening of IgM for EV71-infected patients with clinically suspected hand, foot, and mouth disease (HFMD).

Evaluation of Leptospiral Recombinant Antigens MPL17 and MPL21 for Serological Diagnosis of Leptospirosis by Enzyme-Linked Immunosorbent Assays

Leptospirosis is a zoonosis of multisystem involvement caused by pathogenic strains of the genus Leptospira. In the last few years, intensive studies aimed at the development of a vaccine have provided important knowledge about the nature of the immunological mechanisms of the host. The purpose of this study was to analyze the immune responses to two recombinant proteins, MPL17 and MPL21 (encoded by the genes LIC10765 and LIC13131, respectively) of Leptospira interrogans serovar Copenhageni in individuals during infection. The recombinant proteins were expressed in Escherichia coli as six-His tag fusion proteins and were purified from the soluble bacterial fraction by affinity chromatography with Ni(2+)-charged resin. The recombinant proteins were used to evaluate their ability to bind to immunoglobulin G (IgG) (and IgG subclass) or IgM antibodies in serum samples from patients in the early and convalescent phases of leptospirosis (n = 52) by enzyme-linked immunosorbent assays. The prevalences of total IgG antibodies against MPL17 and MPL21 were 38.5% and 21.2%, respectively. The titers achieved with MPL17 were statistically significantly higher than those obtained by the reference microscopic agglutination test. The specificity of the assay was estimated to be 95.5% for MPL17 and 80.6% for MPL21 when serum samples from individuals with unrelated febrile diseases and control healthy donors were tested. The proteins are conserved among Leptospira strains that cause human and animal diseases. MPL17 and MPL21 are most likely new surface proteins of leptospires, as revealed by liquid-phase immunofluorescence assays with living organisms. Our results demonstrate that these recombinant proteins are highly immunogenic and, when they are used together, might be useful as a means of diagnosing leptospirosis.

The schizophrenia and Toxoplasma gondii connection: Infectious, immune or both?

Recent research has suggested a possible link between toxoplasmic agents and schizophrenia. We aimed to assess this by measuring Toxoplasma gondii-associated antibodies in schizophrenia patients and controls We used a commercially available enzyme-linked immunosorbent assay (ELISA) kit to measure the level of immunoglobulin G (IgG) and IgM antibodies in serum samples from schizophrenia patients (n=40) and from a group of non-schizophrenic control subjects (n=37) Among schizophrenic patients, 16 (40%) showed IgG seropositivity and two (5%) showed IgM seropositivity. Among the control group, five (13.5%) were found have IgG seropositivity and one (2.7%) showed IgM seropositivity. In our study we found that IgG T gondii antibodies were significantly higher in schizophrenia patients compared with controls This study supports the theory that toxoplasmic agents may have a role in the aetiology of schizophrenia.

Diagnostic Value of Specific Local Antibody Production and Nucleic Acid Amplification Technique-Nested Polymerase Chain Reaction (nPCR) in Clinically Suspected Ocular Toxoplasmosis

Objective: The study was to evaluate the diagnostic efficacy of nested polymerase chain reaction (nPCR) using primers targeting B1 gene of Toxoplasma gondii (T. gondii) with Witmer Desmonts coefficient (WDC) technique in intraocular fluids of clinically suspected toxoplasma retino choroiditis (TRC) patients. Materials and Methods: Two hundred and seventy eight specimens from 189 patients (25 TRC patients and 164 controls) consisting of 189 serum samples and 89 intraocular fluids were included in the study. The clinical specimens were categorized into TRC patients (typical TRC lesion-group I & atypical TRC lesion-group II) and controls (voluntary blood donors-group III, patients undergoing uncomplicated cataract surgery-group IV, ocular inflammation of nontoxoplasma origin-group V). Detection of anti T. gondii IgG and IgM antibodies in serum samples and intraocular fluids were performed and WDC was calculated by the standard method. The standardized nPCR was applied on the 89 intraocular fluids. Results: Clinical diagnosis of TRC based on fundus examination was considered to be the “gold standard.” Anti T. gondii IgG/IgM antibodies were detected in serum by ELISA in 95.6% of 25 clinically suspected TRC patients (gp I and II), 28% of gp III, 40.4% of gp IV, and in 58.3% of gpV. Witmer Desmont's coefficient was positive in 72.7% (16/22) and nPCR in 59.1% (13/22) of TRC patients (gp I and II). Both WDC and nPCR were negative in all the controls. The difference in sensitivity of WDC and nPCR was not statistically significant (p = 0.5247). Conclusions: Though both WDC and nPCR were reliable diagnostic techniques for ocular toxoplasmosis, nPCR is more acceptable because of the amount of specimen(s) required, rapidity, cost effectiveness, and direct evidence of T. gondii DNA in the intraocular fluids.

Vertical transmission of Schistosoma japonicum in the rabbit.

The aim of the present study was to confirm observations on the vertical transmission of Schistosoma japonicum in the rabbit. S. japonicum-infected pregnant rabbits were used in this study. Perfusion of mother rabbits was done 9 weeks after infection in order to obtain worm burdens in relation to their initial cercarial dose. Anti-schistosoma specific IgM antibodies in serum samples collected from rabbit kittens were detected by ELISA. Our results showed that gestation period lasted the normal 29-31 days. All the exposed mother rabbits became infected with S. japonicum. Positive IgM antibody OD values were detected in 12 out of the 60 kittens examined (20.0%). In group C and A, 40.0% and 17.9% of the kitten were congenitally infected, respectively. 18.1% of the kittens born to mothers infected with a single dose of 200 cercariae per rabbit were positives; this is not significantly different from that obtained for the 600 dose group (22.2%). Three randomly selected IgM+ kittens harbored between one and two adult worms. The livers of these kittens displayed granulomatous lesions. It is concluded that congenital S. japonicum infection does occur in the rabbit and is affected by the mother stage of pregnancy and to a lesser extent by its infection load.

Increased frequency of Chlamydia pneumoniae antibodies in patients with asthma.

The worldwide increase in asthma incidences and the impact of the disease on public health care have led to new investigations of the cause of the disease. Besides well-defined environmental causes, accumulating evidence suggests that respiratory tract infections play an important role in the pathogenesis of asthma. Among these microorganisms Chlamydia pneumoniae is an intracellular pathogen causing persistent infection. Chlamydia pneumoniae infection has been discussed as possibly inducing the development of asthma. This study was designed to investigate the presence of C. pneumoniae-specific IgG, IgA, and IgM antibodies in serum samples of 33 adults with a clinical history of asthma, positive methacholine test, and reduced FEV(1). Patients with asthma were compared with age-, sex-, and locality-matched control subjects (n = 33). We observed no acute infection either in patients with asthma or in control subjects, but 63% of all investigated individuals had signs of past infection. Chlamydia pneumoniae-specific IgA was detected in 52% of the patients with asthma and in 15% of the healthy control subjects (p < 0.01). Serological evidence of chronic infection with C. pneumoniae (high IgG [> pr = 1:512] and high IgA [> or = 1:40]) was more frequent in patients with asthma (18.2%) compared with control subjects (3.0%) (p < 0.01). Our results provide further evidence that chronic infection with C. pneumoniae is linked to asthma.

Use of IgG- and IgM-specific ELISAs for the assessment of exposure status of chickens to Eimeria species

Simple and reliable methods for the determination of the exposure status of chickens to Eimeia species are required. For this purpose an enzyme-linked immunosorbent assay (ELISA) detecting specific IgG and IgM antibodies in serum samples was evaluated. Sera from chickens hyperimmunised by intramuscular injection of a saline extract of Eimeria tenella sporozoites were used to determine optimal reaction conditions in the ELISA which were found to be at a serum dilution of 1 : 100 and an antigen concentration of 0.2 μg per reaction well. Saline extracts of sporulated oocysts and purified sporozoites of E. tenella were also potent antigens but most studies were carried out with sporozoite antigen. In a trial with 80 chickens, concentrations of serum IgM directed against sporozoite antigen increased significantly 9 days after primary infection with 10 000 oocysts of E. tenella per animal. IgM levels subsequently decreased rapidly reaching a plateau level only slightly higher than uninfected controls by about 15 days post-infection. In chickens challenged with 10 000 oocysts 21 days after primary infection significant increases of IgM levels were observed 2, 6 and 12 days later. In contrast IgG levels increased only slightly after primary infection but significant increases occurred after challenge infection so that by Day 12 after challenge sporozoite-specific IgG levels were much higher than in control chickens. Thus, it may be possible to discriminate between chickens actually infected with Eimeria (as indicated by high levels of antiparasite IgM), chickens which have been repeatedly exposed to Eimeria (as indicated by high levels of antiparasite IgG) and unexposed birds. The applicability of this ELISA, using sporozoite antigen of E. tenella to practical situations was subtantially confirmed, since sampling of over 1000 sera from commercially reared broilers and laying hens indicated that broilers, maintained on medicated food, had low levels of IgM and IgG whereas 84–97% of the laying hens, receiving drug-free feed, had relatively high IgG concentrations. These results reflect low and rare exposure to Eimeria infections in broilers and repeated exposure of the hens.

Peripheral facial palsy and coincidental cytomegalovirus infection or reactivation.

Following the fortuitous demonstration of anti-cytomegalovirus (CMV) IgM antibodies in serum samples from 2 patients with acute peripheral facial palsy (APFP), a systematic study was initiated which provided serological evidence of a coincidental CMV multiplication in 72% of 65 consecutive cases with APFP. Transmission electron microscopy has revealed Herpetoviridae-like virus particles in 56% of urine samples studied. A reactivation of latent CMV at the time of palsy onset is considered the most probable explanation of these findings.