Determination Of IgG Antibodies Research Articles

The seroprevalence of COVID-19 among people living with HIV in Morocco

The association of COVID-19 and HIV infection would seem deadly in terms of prognosis and the possibilities of viral clearance given the immunodeficiency. However, a lower seroprevalence has been reported in some studies compared to that found in the non-HIV population. The objective of this study is to determine the seroprevalence of COVID-19 among people living with HIV (PLHIV) in Morocco. This is a prospective study carried out in the infectious diseases department of the Ibn Rochd University Hospital in Casablanca. We included PLHIV who consulted the Infectious Diseases Day-Hospital service between January 18, 2021 and March 10, 2021. After informed consent, patients completed a survey and had blood drawn for SARS-CoV-2 antibody testing. The determination of IgG antibodies against SARS-CoV-2 in blood was carried out using chemiluminescence microparticle immunoassay technology. We included 418 PLHIV in the study, most patients were male (50.24%), the average age was 40 years, 90.2% of patients were on antiretroviral treatment, 56.7% had a viral load <20 copies/ml, and 47.37% had a CD4 count greater than 500 cells/μL. The IgG test was positive in 53 patients, representing a seroprevalence of 12.68%. None of the patients had clinical signs. Seroprevalence was higher in female patients (58.49%), aged between 30 and 40 years (41.51%), in patients with a negative viral load (64.15%) and a CD4 count greater than 500 cells/mm3 (49.6%). Our study showed that the seroprevalence of COVID-19 was higher among PLHIV compared to people without HIV infection. All the patients had asymptomatic forms which pushes us to evoke a theory, to demonstrate, of the action of antiretrovirals against SARS-CoV-2.

Molecular Characteristics of Blood Serum After Covid-19 Vaccination in a Remote Period

COVID-19 is a dangerous disease with long-lasting consequences. Vaccination contributes to the accumulation of neutralizing anti-S IgG antibodies, reducing the incidence of COVID-19 and its complications. However, in some individuals, the inflammatory process can persist for an indefinite period and lead to a wide range of dysfunctions. The current task is to investigate molecular markers for their detection. The aim of this study is to examine the levels of anti-S IgG antibodies, lactate, glucose, lactate dehydrogenase, and C-reactive protein in the peripheral blood of individuals who have and have not been affected by COVID-19 after vaccination. The research subject is venous blood. Among 547 employees of the Neurosurgery Institute (481 vaccinated against COVID-19 and 66 unvaccinated individuals), levels of anti-S IgG antibodies were investigated, as well as levels of lactate, lactate dehydrogenase, glucose, and C-reactive protein. At the time of the study, among 372 individuals, 16 months had passed from the first vaccination, and 12 months had passed from the second vaccination; in 21 individuals, 12 months had passed after a single vaccination, and in 88 individuals, 16 months had passed from the first vaccination, 12 months from the second, and 6 months from the third vaccination. Methods. Quantitative determination of IgG antibodies to the S protein of the SARS-CoV-2 virus. Confirmation of COVID-19 using the RT-PCR method (Allplex 2019-nCoV kit, SeeGene, Korea). Levels of lactate, lactate dehydrogenase, glucose, and C-reactive protein were determined using reagents from BioSystems (Spain). Statistical analysis of the obtained data was performed using Jamovi software (USA) and the following criteria: χ2 ‒ Kruskal-Wallis, W ‒ Dwass-Steel-Critchlow-Fligner (DSCF), χ2 ‒ Pearson, t ‒ Student, rs ‒ Spearman, τb ‒ Kendall. A statistically significant difference was considered at p < 0.05. Results. The level of anti-S IgG antibodies to the SARS-CoV-2 virus was higher in vaccinated individuals compared to unvaccinated individuals (Kruskal-Wallis χ2=14.09; p < 0.001). A higher level of antibodies to the S protein of the virus was observed when using the Comirnaty vaccine compared to vaccination with Moderna, AstraZeneca, Pfizer, and CoronaVac (Dwass-Steel-Critchlow-Fligner (DSCF): W 4.26, p=0.002; W 4.62, p=0.010; W 4.84, p=0.006, respectively). Vaccination reduces the likelihood of contracting the disease by 1.84 times (Odds Ratio (OR) 1.84; 95% Confidence Interval (CI) 1.02‒3.30; χ2=4.129; p=0.043). However, no statistically significant dependence on the prevention of COVID-19 incidence based on the type of vaccines used was found (Kruskal-Wallis χ2=2.072; p=0.72). A statistically significant difference in C-reactive protein levels is observed between groups with early mild complications and early moderate-severity complications (DSCF: W=4.193, p=0.009). A statistically significant difference in LDH levels is noted between individuals without chronic diseases and those with chronic diseases at the time of the study (Kruskal-Wallis χ2=6.08, p=0.014). In individuals vaccinated against the SARS-CoV-2 virus, a positive correlation is found between the levels of C-reactive protein and lactate dehydrogenase (Kendall's τb 0.134, p < 0.001). The mean levels of lactate among individuals with mild, moderate, and severe forms of COVID-19 are higher than the reference mean; similarly, the mean levels of glucose in these same groups are higher than the reference mean. A positive correlation exists between the levels of lactate and glucose among individuals vaccinated against the SARS-CoV-2 virus (Kendall's τb 0.082, p < 0.01). Conclusions. Vaccination contributes to an increase in antibody levels. The level of antibodies after the third vaccination exceeded the levels after the first (Dwass-Steel-Critchlow-Fligner (DSCF): W 4.42, p=0.005) and second vaccinations (W 4.24, p=0.008). Vaccination reduces the likelihood of COVID-19 infection by 1.84 times (Odds Ratio ‒ 1.84; 95% Confidence Interval 1.02‒3.30; Pearson χ2=4.129; p=0.043). The frequency of COVID-19 incidence is not dependent on the type of vaccine used: AstraZeneca, Comirnaty, CoronaVac, Moderna, Pfizer (Kruskal-Wallis χ2=2.072; p=0.723), and the level of antibodies in the vaccinated individuals' serum. In the post-COVID-19 remote period, regardless of vaccination status, various complications are observed. However, among the vaccinated, the number of individuals without complications or with minimal complications is greater than in the unvaccinated group, while the number of individuals with early and severe complications is lower (Kruskal-Wallis χ2=6.127; p=0.047). A high level of C-reactive protein (DSCF: W=4.19, p=0.009), a tendency toward increased levels of lactate dehydrogenase (DSCF: W=3.27, p=0.054), elevated levels of lactate (2.17+1.23, t=3.34; p=0.002), and glucose (6.06+0.048, t=10.54; p < 0.001) indicate that after recovering from COVID-19, regardless the type of vaccines used, in individuals with distant symptoms there are metabolic changes that are signs of a chronic inflammatory process. Individuals with chronic diseasees show an increase in the level of lactate dehydrogenase (χ2=6.08; p=0.014) and a tendency toward increased levels of C-reactive protein (χ2=3.74; p=0.053). Molecular markers of inflammation such as increased levels of lactate, glucose, C-reactive protein, and lactate dehydrogenase are informative for identifying individuals with an inflammatory process in the post-COVID-19 remote period.

Interactions of humoral immune response indicators and parameters of systemic inflammatory response in patients with post-COVID-19 syndrome

Objective. To assess the state of the systemic inflammatory response and humoral immune response in middle-aged patients came through COVID-19 infection in mild and moderate severity. Materials and methods. A cohort single-center study involving 83 patients came through COVID-19 infection in mild and moderate severity (women - 69.9% (58 patients), men - 30.1% (25 patients); median age 53 years [49; 56] was conducted over the period 2022-2023. All patients underwent clinical examination, evaluation of humoral response with determination of IgG and IgM antibodies to SARS-CoV-2 virus, as well as concentration of interleukins: interleukin-1β, interleukin-4, interleukin-6, interleukin-8, interleukin-10, high-sensitivity C-reactive protein, tumour necrosis factor α, transforming growth factor β1 and procalcitonin concentrations. Patients were divided into three groups: 1-3 months; 3-6 months; and 6 months to 1 year after COVID-19 infection. Results. Within a year the percentage of IgM-positive patients in all patient groups was about a quarter (25 %, 21 % and 25 % respectively). While remaining within the reference values for the whole group, procalcitonin and interleukin-10 levels in the selected cohort exceeded those of the test-negative cohort (p = 0.0053 and p = 0.0044, respectively), which we considered as persistent chronic compensated inflammation. Conclusion. A quarter of patients who came through COVID-19 infection in mild and moderate severity have persistently positive IgM levels for a year, combined with proinflammatory status according to systemic inflammatory response parameters.

Sensitization to avian and fungal proteins in different work environments

IntroductionHypersensitivity pneumonitis (HP) is usually caused by the inhalation of avian and fungal proteins. The present study assesses a cohort of Urban Pest Surveillance and Control Service (UPSCS) workers with high exposure to avian and fungal antigens, in order to identify their degree of sensitization and the potential risk of developing HP.MethodsWorkers were divided according to their work activity into Nest pruners (Group 1) and Others (Group 2). All individuals underwent a medical interview, pulmonary function tests and the determination of specific IgG antibodies. Antigenic proteins of pigeon sera were analysed using two-dimensional immunoblotting. Proteins of interest were sequenced by liquid-chromatography–mass spectrometry (LC–MS).Results101 workers were recruited (76 men, average age: 42 yrs); (Group 1 = 41, Group 2 = 60). Up to 30% of the study population exhibited increased levels of IgGs to pigeon, small parrot and parrot, and up to 60% showed high levels of Aspergillus and Penicillium IgGs. In Group 1, specific parakeet and Mucor IgGs were higher (p = 0.044 and 0.003 respectively) while DLCO/VA% were lower (p = 0.008) than in Group 2. Two-dimensional immunoblotting showed protein bands of 20–30 KDa recognized by HP patients but not by workers. LC–MS analysis identified Ig Lambda chain and Apolipoprotein A-I as candidate proteins for distinguishing HP patients from exposed workers.ConclusionsTwo pigeon proteins were identified that may play a role in the development of pathological differences between HP patients and exposed workers. DLCO/VA may have a predictive value in the development of HP disease.

Rapid increase of SARS-CoV-2 seroprevalence during the second half of the COVID-19 pandemic year 2020 in the adult urban Albanian population

BackgroundThis study aims to assess the changes in COVID-19 seroprevalence among the adult urban population of Albania between July and December 2020, when the Wuhan strain of SARS-CoV-2 virus was still prevalent in the country. MethodsTwo independent, randomly selected samples of individuals aged 20–70 years residing in Metropolitan Tirana, Albania, were collected in June–July and December 2020. ELISA method was used for serological testing to determine IgG antibodies anti-S1-SARS-CoV-2. Results: The proportion of individuals classified as seropositive in early July was 7.5% (95% CI: 4.3%–10.7%), which increased 6.5 times in late December 2020, reaching 48.2% (95% CI: 44.8%–51.7%). The increasing seroprevalence rates in the study mirrored the trend of detected COVID-19 cases from June to December 2020 in Albania. However, they demonstrate a much higher cumulative incidence of the SARS-COV-2 infection in the community than the reported COVID-19 cases. Conclusion: The rapid increase in SARS-CoV-2 seroprevalence observed in Tirana City by the end of 2020 was likely a result of several factors, including the very low infection exposure between March–May 2020 when the entire city was in a lockdown, followed by the high susceptibility of the population due to naïve immunity. Despite the high observed seroprevalence at the end of December 2020, COVID-19 incidence continued to increase in Albania through 2021 and 2022 following the new virus variant surges.

Is Slovakia Almost a Hepatitis D Free Country?

It is assumed that the prevalence of hepatitis D in HBsAg-positive individuals reaches 4.5-13% in the world and on average about 3% in Europe. Data from several European countries, including Slovakia, are missing or are from an older period. We analyzed all available data on hepatitis D from Slovakia, including reports from the Slovak Public Health Authority and the results of one prospective study, and three smaller surveys. The determination of anti-HDV IgG and IgM antibodies and/or HDV RNA was used to detect hepatitis D. In the years 2005-2022, no confirmed case of acute or chronic HDV infection was reported in Slovakia. The presented survey includes a total of 343 patients, of which 126 were asymptomatic HBsAg carriers, 33 acute hepatitis B, and 184 chronic hepatitis B cases. In a recent prospective study of 206 HBsAg-positive patients who were completely serologically and virologically examined for hepatitis B and D, only 1 anti-HDV IgG-positive and no anti-HDV IgM or HDV RNA-positive cases were detected. In other smaller surveys, two anti-HDV IgG-positive patients were found without the possibility of HDV RNA confirmation. In total, only 3 of 329 HBsAg-positive patients (0.91%) tested positive for anti-HDV IgG antibodies, and none of 220 tested positive for HDV RNA. The available data show that Slovakia is one of the countries with a very low prevalence of HDV infection, reaching less than 1% in HBsAg-positive patients. Routine testing for hepatitis D is lacking in Slovakia, and therefore it is necessary to implement testing of all HBsAg-positive individuals according to international recommendations.

Поширеність антитіл до SARS-CoV-2 у дітей та підлітків: одноцентрове дослідження

Despite the fact that children with COVID-19 are usually asymptomatic or mild, infection with SARS-CoV-2 is more likely to lead to the development of an antibody response. Understanding humoral immunity to SARS-CoV-2, including in children, is critical for future public health and vaccination strategies. Children with chronic diseases deserve special attention. Purpose - to study the prevalence of positive antibodies to SARS-CoV-2 in children and adolescents who were in paediatric hospital without signs of viral disease to develop future healthcare strategies. Materials and methods. In 32 children aged 6-17 years (14 (43.8%) boys and 16 (56.2%) girls) quantitative determination of IgG antibodies to SARS-CoV-2 in blood serum was carried out by enzyme immunoassay using commercial SARS-CoV-2 S1\RBD IgG Ab ELISA (TECAN, IBL International GmbH, Germany). Results. The majority (n=27, 84.4%) of children had a positive level of class G antibodies to SARS-CoV-2. 7 (25.9%) children had a positive PCR test in their anamnesis, 6 (18.8%) persons provided information about the infection transmitted by family members. Clinical manifestations characteristic of SARS-CoV-19 were present in 2 (7.4%) children. Parents of 18 (66.7%) children claimed that their children had no symptoms of COVID-19, while family members of 6 (33.3%) children had cases of the disease. All children (n=6, 18.8%) who were vaccinated with two doses of Comirnaty® vaccine had positive IgG antibodies to SARS-CoV-2. Antibodies to SARS-CoV-2 were absent in 5 (15.4%) people, all of them were patients with type 1 diabetes. Conclusions. The study of the prevalence of antibodies to SARS-CoV-2 provides important information about circulating antibodies against SARS-CoV-2 in children and adolescents, in particular those with chronic diseases. The obtained results showed the predominant seropositivity of children, which is formed regardless of the clinical manifestations of the disease. A high level of antibodies under the conditions of revaccination confirms the benefit of revaccination of children to strengthen memory formation. The research was carried out in accordance with the principles of the Helsinki Declaration. The study protocol was approved by the Local Ethics Committee of the participating institution. The informed consent of the patient was obtained for conducting the studies. No conflict of interests was declared by the authors.

Evaluation of T and B cell immunophenotyping and antibody response post Covid-19 vaccination

PurposeTo evaluate T and B cell subsets and IgG antibodies in response to SARS-CoV-2 post COVID-19 vaccination. MethodsA total of 50 healthy adults (18–60 years) receiving anti-SARS-CoV-2 vaccination (COVISHIELD) were recruited for the study. Blood samples were collected from participants at 3 time points; just before vaccination (Visit 0, V0), just before booster dose (Visit 1, V1) and 6th month after 1st dose (Visit 2, V2). Peripheral blood mononuclear cell isolation was done and evaluated for T and B cell subsets by Flow cytometry. Quantitative determination of IgG antibodies to SARS-CoV-2 was done by Chemiluminescence immunoassay in all samples. Final data for all three visits was available for 37 participants who remained healthy.Ethics approval was obtained from Medanta Institution of Ethics Committee vide MICR No. 1290/2021 dated 24th May 2021. ResultsMean age of the participants was 34.6 ​± ​5.7 years (Range: 24–45 years). Highly significant improvement in SARS-CoV-2 IgG levels was observed after each visit {Mean IgG: (V0 v/s. V1: 133.8 ​± ​339.2AU/ml v/s. 434.5 ​± ​519.2AU/ml; p-value ​= ​0.003) and V0 v/s. V2: 133.8 ​± ​339.2AU/ml v/s. 420.9 ​± ​394.2AU/ml; p-value ​= ​0.002) Between visits 0 and 1, the mean value for CD4 Naïve T cells showed significant increase, while CD4 central memory (CM) T cells showed significant decrease. Between visits 0 and 2 the mean values for CD4 Naïve T cells, CD8 Naïve T cells and Pre germinal centre (Pre GC) B cells showed significant increase. During the same period the mean values for CD4CM, CD8 effector memory (EM) and CD8 CM T cells showed significant decrease. ConclusionIt is concluded that both, humoral and cellular immunity, play an important role in maintaining immunity against COVID-19 infection, following COVISHIELD vaccination. Moreover, in subjects with normalisation of antibody levels post vaccination, persistence of T cell subsets may still offer some immunity.

Mosquito bites and stage-specific antibody responses against Plasmodium falciparum in southern Ghana

BackgroundThe human host elicits specific immune responses after exposure to various life stages of the malaria parasite as well as components of mosquito saliva injected into the host during a mosquito bite. This study describes differences in IgG responses against antigens derived from the sporozoite (PfCSP), asexual stage parasite (PfEBA175) and the gametocyte (Pfs230), in addition to an Anopheles gambiae salivary gland antigen (gSG6-P1), in two communities in Ghana with similar blood stage malaria parasite prevalence.MethodsThis study used archived plasma samples collected from an earlier cross-sectional study that enrolled volunteers aged from 6 months to 70 years from Simiw, peri-urban community (N = 347) and Obom, rural community (N = 291). An archived thick and thin blood smear for microscopy was used for the estimation of Plasmodium parasite density and species and DNA extraction from blood spots and P. falciparum confirmation was performed using PCR. This study used the stored plasma samples to determine IgG antibody levels to P. falciparum and Anopheles salivary antigens using indirect ELISA.ResultsIndividuals from Simiw had significantly higher levels of IgG against mosquito gSG6-P1 [median (95%CI)] [2.590 (2.452–2.783) ng/mL] compared to those from Obom [2.119 (1.957–2.345) ng/mL], p < 0.0001. Both IgG responses against Pfs230proC (p = 0.0006), and PfCSP (p = 0.002) were significantly lower in volunteers from Simiw compared to the participants from Obom. The seroprevalence of PfEBA-175.5R (p = 0.8613), gSG6-P1 (p = 0.0704), PfCSP (p = 0.7798) IgG were all similar in Obom and Simiw. However, Pfs230 seroprevalence was significantly higher at Obom compared to Simiw (p = 0.0006). Spearman correlation analysis showed no significant association between IgG responses against gSG6-P1, PfCSP, Pfs230proC and PfEBA-175.5R and parasite density at both Obom and Simiw (p > 0.05).ConclusionIn conclusion, the study showed that participants from Simiw had higher concentrations of circulating gSG6-P1 IgG antibodies but lower concentrations of P. falciparum antibodies, PfCSP IgG and Pfs230proC IgG compared to participants from Obom.

355 Unraveling and targeting the innate immune response in Multisystem Inflammatory Syndrome in Children (MIS-C)

OBJECTIVES/GOALS: The innate immune responses to Multisystem Inflammatory Syndrome in Children (MIS-C) are not fully known. Using samples from MIS-C, we will assess the cellular responses and develop a novel Tri-Specific Killer Engager (TRiKE) that engages innate immune cells to improve those responses. METHODS/STUDY POPULATION: We collected blood samples from 60 pediatric patients from which we isolated plasma and peripheral blood mononuclear cells. We received blood samples from 13 MIS-C, 32 severe acute COVID, 5 COVID-19 asymptomatic, and 15 COVID-19 negative patients. Using plasma, we then performed ELISAs to determine IgG antibody levels against SARS-CoV-2 and plaque reduction neutralization tests to determine neutralizing antibody functions. We isolated DNA to look at Fc receptor genetics. We also utilized utilize flow cytometry assays determine the phagocytosis and killing abilities of the innate cells from these patients. This data will be correlated with clinical outcomes. Additionally, we have developed a novel SARS-CoV-2 TRiKE which directs natural killer (NK) cell killing specifically to of COVID-19 infected cells. RESULTS/ANTICIPATED RESULTS: MIS-C patients had higher IgG antibody titers against SARS-CoV-2 compared to children with symptomatic or asymptomatic COVID. MIS-C patients also neutralized SARS-CoV-2 more effectively than children with acute symptomatic or asymptomatic COVID-19. We found natural killer cells and monocytes are dysfunctional in MIS-C patients and do not kill SARS-CoV-2 infected cells as well. Specifically, NK cells do not kill COVID-19 infected cells as well. To combat this, we have successfully generated and are now testing a Tri-Specific Killer engager (TRiKE) which binds one ends to NK cells, one end to the Spike protein on COVID-19 infected cells and contains IL-15 to improve NK cell function. We anticipate that we can improve NK cell killing of COVID-19 infected cells with this TRiKE. DISCUSSION/SIGNIFICANCE: We found that MIS-C patients have antibodies that can neutralize SARS-CoV-2 but that that innate immune cells that engage antibodies are dysfunctional. We are have successfully developed and are targeting this response with a TRiKE to improve innate immune cell functional; this may serve as an adjunctive therapeutic if proven successful.

Dynamics of Anti-S IgG Antibodies Titers after the Second Dose of COVID-19 Vaccines in the Manual and Craft Worker Population of Qatar.

There is limited seroepidemiological evidence on the magnitude and long-term durability of antibody titers of mRNA and non-mRNA vaccines in the Qatari population. This study was conducted to generate evidence on long-term anti-S IgG antibody titers and their dynamics in individuals who have completed a primary COVID-19 vaccination schedule. A total of 300 male participants who received any of the following vaccines BNT162b2/Comirnaty, mRNA-1273, ChAdOx1-S/Covishield, COVID-19 Vaccine Janssen/Johnson, or BBIBP-CorV or Covaxin were enrolled in our study. All sera samples were tested by chemiluminescent microparticle immunoassay (CMIA) for the quantitative determination of IgG antibodies to SARS-CoV-2, receptor-binding domain (RBD) of the S1 subunit of the spike protein of SARS-CoV-2. Antibodies against SARS-CoV-2 nucleocapsid (SARS-CoV-2 N-protein IgG) were also determined. Kaplan-Meier survival curves were used to compare the time from the last dose of the primary vaccination schedule to the time by which anti-S IgG antibody titers fell into the lowest quartile (range of values collected) for the mRNA and non-mRNA vaccines. Participants vaccinated with mRNA vaccines had higher median anti-S IgG antibody titers. Participants vaccinated with the mRNA-1273 vaccine had the highest median anti-S-antibody level of 13,720.9 AU/mL (IQR 6426.5 to 30,185.6 AU/mL) followed by BNT162b2 (median, 7570.9 AU/mL; IQR, 3757.9 to 16,577.4 AU/mL); while the median anti-S antibody titer for non-mRNA vaccinated participants was 3759.7 AU/mL (IQR, 2059.7-5693.5 AU/mL). The median time to reach the lowest quartile was 3.53 months (IQR, 2.2-4.5 months) and 7.63 months (IQR, 6.3-8.4 months) for the non-mRNA vaccine recipients and Pfizer vaccine recipients, respectively. However, more than 50% of the Moderna vaccine recipients did not reach the lowest quartile by the end of the follow-up period. This evidence on anti-S IgG antibody titers should be considered for informing decisions on the durability of the neutralizing activity and thus protection against infection after the full course of primary vaccination in individuals receiving different type (mRNA verus non-mRNA) vaccines and those with natural infection.

Antibodies of the immunoglobulin a isotype to novel antigens in early axial spondyloarthritis.

There is an unmet need for biomarkers to identify patients with axial spondyloarthritis (axSpA). Increasing evidence suggest the presence of autoantibodies in a subset of axSpA patients. The aim of this study was to identify novel IgA antibodies in early axSpA patients and to determine their diagnostic potential in combination with previously determined IgG antibodies against UH (Hasselt University)-axSpA-IgG antigens. An axSpA cDNA phage display library constructed from axSpA hip synovium, was used to screen for novel IgA antibodies in plasma from early axSpA patients. The presence of these antibodies against novel UH-axSpA-IgA antigens was determined in two independent axSpA cohorts, in healthy controls and in patients with chronic low back pain. We identified antibodies to 7 novel UH-axSpA-IgA antigens, of which 6 correspond to non-physiological peptides and 1 to the human histone deacetylase 3 (HDAC3) protein. IgA antibodies against 2 of these 7 novel UH-axSpA-IgA antigens and IgG antibodies against 2 of the previously identified antigens were significantly more present in early axSpA patients from the UH cohort (18/70, 25.7%) and the (Bio)SPAR cohort (26/164, 15.9%), compared to controls with chronic low back pain (2/66, 3%). Antibodies to this panel of 4 antigens were present in 21.1% (30/142) of patients with early axSpA from the UH and (Bio)SPAR cohorts. The positive likelihood ratio for confirming early axSpA using antibodies to these 4 UH-axSpA antigens was 7.0. So far, no clinical correlation between the novel identified IgA antibodies and inflammatory bowel disease could be identified. In conclusion, screening an axSpA cDNA phage display library for IgA reactivity resulted in the identification of 7 novel UH-axSpA-IgA antigens, of which 2 show promising biomarker potential for the diagnosis of a subset of axSpA patients, in combination with previously identified UH-axSpA-IgG antigens.

Assessment of diagnostic value of HLA-DQ2/DQ8 typing and anti-tissue transglutaminase antibodies as an alternative to duodenal biopsy in pediatric celiac disease

Introduction/Objective. The objective of the paper is to assess the applicability of serum anti-tissue transglutaminase (tTG) antibodies IgA and IgG concentration and HLA-DQ2/DQ8 typing as a non-invasive alternative to duodenal biopsy in diagnosing celiac disease (CD) in pediatric population. Methods. A prospective cohort study included a total of 179 pediatric patients aged 1?18 years. Determination of tTG IgA and tTG IgG antibodies and human leukocyte antigen (HLA) DQ2/DQ8 typing was performed for all patients. Histology of duodenal biopsies was interpreted by the modified Marsh scoring system. Results. The diagnosis of CD was confirmed in 101 (56%) patients of the studied population. In cases of CD, HLA-DQ2/DQ8 was positive in 100 patients (99%). The tTG IgA antibodies in concentration higher than 100 U/ml were detected in 77 (76.2%) of the CD patients and in significantly smaller number for tTG IgG [29 (28.7%)] (p &lt; 0.001). Statistically highly significant association of duodenal lesions Marsh grade 3 with concentration of tTG IgA 10-fold higher than the upper level of normal (ULN) was established (p &lt; 0.001) Conclusion. Concentration of tTG IgA 10-fold higher than ULN is significantly positively correlated with Marsh grade 3 histopathology findings. Specific antibodies determination in combination with HLA-DQ2/ DQ8 typing proves to be sufficient for a diagnosis of CD, supporting the fact that duodenal biopsy may be avoided in a significant majority of patients ? 75%.

ТУБЕРКУЛЕЗ ОРГАНОВ ДЫХАНИЯ И COVID-19 У ДЕТЕЙ И ПОДРОСТКОВ: КЛИНИКА И ИММУНОЛОГИЧЕСКИЕ АСПЕКТЫ

Objective: to investigate T cell immune response to SARS-CoV-2 in children and adolescents with pulmonary TB with history of the novel coronavirus disease and/or exposure to the novel coronavirus infection. Materials and methods. We chose patients aged 12–17 years with pulmonary TB and different variants of interaction with the novel coronavirus infection. We studied 15 blood samples using the TigraTest® SARS-CoV-2 assay (after 5 months of the disease or exposure to COVID-19), and the qualitative determination of IgG antibodies (after 2, 4, and 6 months). We performed complex clinical, microbiological, and radiological studies to assess the dynamics of TB process. The course and severity of COVID-19 disease was assessed according to the methodological recommendations of the Russian Ministry of Health (as of 17.11.2021). Results. Positive results of TigraTest® SARS-CoV-2 were obtained in 9 out of 11 patients (after the disease or exposure to COVID-19), negative results were obtained in 2 patients without IgG antibodies to SARS-CoV-2. The patients had mild course of COVID-19; exacerbations were not observed. In 4 patients (without history of COVID-19 disease, exposure was not reliably established) negative T cell and humoral immune responses were observed. Conclusion. It is important to investigate T cell immune response to SARS-CoV-2 due to rapid disappearance of IgG antibodies (by the 4th month after the disease). The absence of IgG antibodies impedes the prognosis of nosocomial infection in a hospital.

Soroprevalência de anticorpos contra o vírus da cinomose canina, parvovírus e adenovírus em cães de um abrigo de animais brasileiro

ABSTRACT This study aimed to identify and compare the seroprevalence for canine distemper virus (CDV), canine parvovirus (CPV), and canine adenovirus (CAV) between newly admitted and already sheltered dogs. 122 dogs over six months of age and unvaccinated upon admission were sampled and divided into two groups: (A) newly admitted dogs and (B) dogs sheltered for at least two months. Sera were collected to determine IgG antibody titers against CDV, CPV, and CAV. We conducted a descriptive analysis of the samples and a chi-square test to investigate the relationship between potential elements associated with protective antibody titers. The results were: 56.5% of the dogs had protective levels of antibodies to all three pathogens. Dogs in group A had lower titers compared to those in group B for all three pathogens, with significant differences for CDV and CAV. We found no significant difference between the proportion of seropositive dogs and their age or reproductive status. The study suggests that the examined pathogens can circulate in the animal shelter and that dogs can be more exposed to these pathogens in the shelter than in the urban environment. Therefore, an effective immunization program should be carried out on all animals upon admission to shelters.

State of anti-rubella virus population immunity in the Republic of Belarus and Russian Federation

To confirm a progress towards the rubella elimination, immunization coverage indicators and the results of serological studies are used. At the same time, the most objective method of assessing collective immunity is a serological examination. The purpose of this work was to compare the results of assessing state of population immunity against rubella virus in the Republic of Belarus and the Russian Federation using various vaccines and different approaches to study organization and cohort selection screening and monitoring. 2019 laboratory studies to determine IgG antibodies against rubella virus were carried out by ELISA method of the unified enzyme immunoassay system Ecolab (Russia). The serum study results of 701 subjects aged 245 years from all the 7 regions of the Republic of Belarus (screening study) and 55 082 subjects aged 349 years (monitoring) from 85 regions of the Russian Federation were analyzed. The results were evaluated in three age groups children, adults, total cohort by using a threshold level of 8385% seropositive individuals sufficient to prevent virus transmission. The antigenic composition of the rubella component in the mono- and complex vaccines respectively used in the Russian Federation and the Republic of Belarus is identical, which allows to compare the state of population immunity against rubella virus therein without taking into account an influence of the vaccine strain. Studies have shown that while using varying vaccine preparations and approaches to organization of serological examination, both in the Republic of Belarus and the Russian Federation, rubella virus-specific IgG level was detected at rather high level in all age groups comprising more than 90%. The portion of rubella seropositive subjects in entire country was 95.44% in the Republic of Belarus and 97.14% in the Russian Federation. Moreover, the level of specific antibodies remains high, despite the low incidence rate and absence of booster effect in both countries. The mean group antibody concentration in seropositive patients in all age groups was quite high and exceeded the minimum protective concentration (11 IU/ml) by 10 or more times. The data obtained indicate the legitimacy of using a serological study of collective rubella immunity as a routine or seromonitoring as well as periodic or screening investigation.

The effect of endogenous cortisol on the course of H.pylori-associated gastroduodenal diseases in adolescents

Background. The clinical picture and course of Н.pylori-dependent gastroduodenal diseases in adolescents have some characteristics, which complicate the diagnosis and treatment. The purpose was to investigate the level of cortisol in the blood of adolescents with Н.pylori-dependent gastroduodenal diseases. Materials and methods. A group of 96 patients (15–18 years old) was formed and divided into subgroups depending on the nosology (chronic gastroduodenitis, chronic erosive gastroduodenitis, duodenal ulcer) and gender. A comparison group included children of the same age. Fibroesophagogastroduodenoscopy was used to determine the endoscopic criteria for Helicobacter pylori (HP) and to perform a shield biopsy of the gastric mucosa (antrum and body of the stomach) and duodenum. HP infection was confirmed by enzyme immunoassay with qualitative and quantitative determination of IgG antibodies to HP in blood serum (UBI MAYIWELL™, USA). Evaluating the level of cortisol in the blood was carried out using a standard test system (Immunotech, Czech Republic). Results. The total frequency of HP detection was 54.2 %. It is worth noting that only 33.3 % of adolescents with H.pylori-associated gastroduodenal diseases have toxic CagA strains, while among patients with H.pylori-associated chronic erosive gastroduodenitis, such strains were detected in 70.8 % of cases. Children with duodenal ulcer are characterized by the highest number of HP strains in biopsies of the mucous membrane — 83.3 %. The level of cortisol in the blood of adolescents with pathology of the upper gastrointestinal tract was significantly higher than that in the comparison group (906.33 ± 43.56 nmol/ml and 666.21 ± 33.42 nmol/ml, respectively; p &lt; 0.05). The highest cortisol content in the blood was registered in patients with duodenal ulcer, with a predominance of higher indicators among adolescent boys. Significantly higher blood levels of cortisol were found in the stage of exacerbation and with a high degree of activity of the inflammatory process. Conclusions. In adolescence, inflammatory and destructive changes in the duodenal mucosa are potentiated by a high level of cortisol in the blood, it is higher in adolescent boys, with a high degree of inflammatory activity and in association with Helicobacter pylori infection.

Antibody levels of measles, rubella and mumps viruses in healthy population in Shanghai from 2010 to 2020

Objective: To determine IgG antibody levels of measles, rubella, mumps in healthy population in Shanghai from 2010 to 2020 and analyze the trend of antibody changes in different age groups. Methods: 10 828 healthy people without measles, rubella and mumps in Shanghai were included in the study from 2010 to 2020. Serum samples were collected from 12 age groups, and the serum IgG antibody of measles, rubella and mumps were detected by ELISA. The difference of antibody positive rates and antibody levels were analyzed. Results: The median age M (Q1, Q3) of 10 828 objects were 8 years old (9 months old, 20 years old). Males accounted for 48.34% (5 234/10 828) and females accounted for 50.92% (5 514/10 828). Unknown gender information accounted for 0.74% (80/10 828), and 27.03% (2 927/10 828) of participants had unknown MMR immunization history. The total positive rates of measles, rubella and mumps IgG antibody were 76.78%, 64.46% and 64.29% and their GMCs were 541.45 mIU/ml, 31.76 IU/ml and 133.73 U/ml respectively. There were significant differences in serum IgG antibody GMC of measles, rubella and mumps in each year (Fmeasles=180.74, P<0.001; Frubella=189.95, P<0.001; Fmumps=122.40, P<0.001). The positive rate of measles antibody was higher than that of rubella and mumps, and the difference was statistically significant (χ²=518.09, P<0.001). Conclusion: The level of measles IgG antibody in healthy people in Shanghai is higher, while the level of rubella and mumps IgG antibody is slightly lower.

Immunogenicity and Safety of mRNA Anti-SARS-CoV-2 Vaccines in Patients with Systemic Lupus Erythematosus.

Vaccination is the most effective preventive measure to control the spread of COVID-19 and reduce associated complications. This study aims to evaluate the efficacy and safety of mRNA COVID-19 vaccines in patients with systemic lupus erythematosus (SLE). A total of 41 adult SLE patients receiving two doses of the SARS-CoV-2 mRNA Comirnaty-BioNTech/Pfizer vaccine were enrolled. The quantitative determination of anti-trimeric spike protein-specific IgG antibodies to SARS-CoV-2 was assessed before (T0), 21 days after the administration of the first dose of the vaccine (T1), and between 21 and 28 days after the second dose (T2). They were compared with the same determinations from a cohort of 29 patients with C1-esterase inhibitor deficiency hereditary angioedema (C1-INH-HAE) as controls. All the SLE patients and controls demonstrated a positive serological response after a single dose of the vaccine (T1), which significantly increased after the second dose (T2). No significant difference was found between SLE patients and controls at T1 [t(52.81) = −0.68; p = 0.49] and at T2 [t(67.74) = −0.22; p = 0.825]. Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) analysis showed that the vaccine did not influence SLE activity or caused disease flare in our cohort. In conclusion, COVID-19 vaccines produced a satisfactory response in SLE patients without variation in the disease activity.

Use of Tumor Necrosis Factor-α Antagonists Is Associated With Attenuated IgG Antibody Response Against SARS-CoV-2 in Vaccinated Patients With Inflammatory Bowel Disease.

IntroductionPatients with Inflammatory Bowel Disease (IBD) frequently receive immunomodulating treatment, which may render them at increased risk of an attenuated immune response upon vaccination. In this study, we assessed the effects of different types of commonly prescribed immunosuppressive medications on the serological response after vaccination against SARS-CoV-2 in patients with IBD.MethodsIn this prospective observational cohort study, IgG antibody titers against SARS-CoV-2 were measured 2-10 weeks after completion of standard vaccination regimens in patients with IBD. Clinical characteristics, previous history of SARS-CoV-2 infection, type of vaccine (mRNA- or vector-based) and medication use were recorded at the time of sampling. Subsequently, a chemiluminescent microparticle immunoassay was used for the quantitative determination of IgG antibodies against the receptor-binding domain (RBD) of the S1 subunit of the spike protein of SARS-CoV-2.ResultsThree hundred and twelve (312) patients with IBD were included (172 Crohn’s disease [CD] and 140 ulcerative colitis [UC]). Seroconversion (defined as titer of >50 AU/ml) was achieved in 98.3% of patients. Antibody concentrations were significantly lower in patients treated with TNF-α-antagonists vs. non-users of TNF-α-antagonists (geometric mean [95% confidence interval]: 2204 [1655-2935] vs. 5002 [4089-6116] AU/ml, P<0.001). In multivariable models, use of TNF-α-antagonists (P<0.001), vector vaccines (P<0.001), age (>50 years) (P<0.01) and CD (P<0.05) were independently associated with lower anti-SARS-CoV-2 antibody titers. In patients who received mRNA vaccines, users of thiopurines (either prescribed as monotherapy or in combination with biologicals) demonstrated significantly lower antibody titers compared to thiopurine non-users (P<0.05).ConclusionDespite reassuring findings that most patients with IBD have detectable antibodies after anti-SARS-CoV-2 vaccination, TNF-α-antagonists were found to be strongly associated with an attenuated IgG antibody response after vaccination against SARS-CoV-2, independent of vaccine type, the time elapsed after vaccination and blood sampling, prior SARS-CoV-2 infection and patient age. Patients treated with thiopurines and receiving mRNA-based vaccines demonstrated lower anti-SARS-CoV-2 antibody titers compared with non-users.