IgM Antibodies Research Articles

Protective effects of oyster polypeptide on cyclophosphamide-induced immunosuppressed rats.

Oyster polypeptide (OP) is a mixture of oligopeptides extracted from oysters through enzyme lysis, separation, and purification. It is associated with immunomodulatory effects, but the underlying mechanisms are not known. This study therefore combined proton nuclear magnetic resonance (1H-NMR) urinary metabolomics and 16S rRNA gene sequencing of the gut microbiome to determine the immunoprotective mechanisms of OP in rats subjected to cyclophosphamide-induced immunosuppression. Oyster polypeptide restored the body weight and the structure of spleen and thymus in rats with cyclophosphamide-induced immunosuppression. It upregulated the levels of white blood cells (WBCs), hemoglobin (HGB), platelets (PLT), red blood cells (RBCs), immunoglobulin G (IgG), immunoglobulin M (IgM), cytokines such as interleukin‑6 (IL-6) and tumor necrosis factor-α (TNF-α), and increased the numbers of CD3+ and CD4+ T cells in the immunosuppressed rats. The 1H-NMR metabolomics results showed that OP significantly reversed the levels of ten metabolites in urine, including 2-oxoglutarate, citrate, dimethylamine, taurine, N-phenylacetylglycine, alanine, betaine, creatinine, uracil, and benzoate. The 16S rRNA gene sequencing results showed that OP restored the gut microbiome homeostasis by increasing the abundance of beneficial bacteria and reducing the abundance of pathogenic bacteria. Finally, a combination of metabolomics and microbiomics found that the metabolism of taurine and hypotaurine, and the metabolism of alanine, aspartate, and glutamate were disturbed, but these metabolic pathways were restored by OP. This study demonstrated that OP had immunoprotective effects in rats with cyclophosphamide-induced immunosuppression by restoring key metabolic pathways and the gut microbiome homeostasis. Our findings provide a framework for further research into the immunoregulatory mechanisms of OP and its potential use in drugs and nutritional supplements. © 2024 Society of Chemical Industry.

Dengue Hemorrhagic Fever Presenting with Acute Abdomen in a Non- Government Tertiary Care Hospital in Bangladesh

A 60-year-old diabetic and hypertensive post-menopausal lady, presented at a tertiary care Hospital in Dhaka, Bangladesh with severe abdominal pain in the right middle and lower abdomen, associated with oliguria for 1 day. She also gave history of having high grade fever and headache for 3 days, which subsided 2 days ago. On examination, she was afebrile, mildly dehydrated, tachycardic (PR- 110/min), hypotensive (BP- 90/60 mm Hg), Tourniquet Test was positive. Her abdomen was tense and diffusely tender, especially in the right middle and lower parts, bowel sound was present, no organomegaly or lump was found. S. Lipase was normal, Anti-dengue Antibody IgM and IgG were positive, CBC revealed Hemoglobin – 8.6 gm/dL, Hematocrit was raised- 52%, Platelet count was 16000/ microliter, Stool for OBT was negative, RBS- 16 mmol/L and Urine RME and ketone bodies was negative. A provisional diagnosis of Dengue Hemorrhagic fever with suspected intra- abdominal bleeding was made and she was shifted to ICU.

Significance of Serological Markers in Diagnosis of Acute Dengue Infection: 2021 Outbreak

Objective: To highlight the significance of Dengue anti-IgM and Dengue NS1 antigen in diagnosing Acute Dengue infection. Study Design: Cross-sectional study. Place and Duration of Study: Virology Department, Armed Forces Institute of Pathology, Rawalpindi Pakistan, from Sep to Nov 2021. Methodology: One hundred and fifty Dengue NS1-positive patients of either gender with age≥5 years were included. ELISA tested patients for detection of Dengue anti-IgM antibody. A questionnaire was used to collect demographic and personal data of each patient. Results: Out of 150 dengue NS1 positive samples, 26(17%) were positive for dengue anti-IgM. In collected samples, Dengue serological markers (NS1 and anti-IgM) positivity was observed based on ‘the day of onset of symptoms. On days 1 and 2, 54 and 44 NS1 positive samples were collected, respectively, but no one was found positive for anti-IgM. Anti-IgM was detected on day-3 and onwards. 27% Dengue anti-IgM positivity was found on day-3, which increased gradually as the time of infection increased. On day four, it was 53%; on day 5, it was 55%; on day-6, it was 60%; on day 7, it was 75%; and on day 8, it was 100%. Conclusions: The findings of present study suggested that anti-Dengue IgM antibodies are less significant than the Dengue NS1 antigen in diagnosing acute dengue infection.

Prominent early adulthood hyperferritinemia in scrub typhus

Background: Scrub typhus is an acute infectious disease, caused by Orientia tsutsugamushi. It is endemic to a geographically distinct region of Japan, Taiwan, China, and South Korea, known as the tsutsugamushi triangle, as well as in Nepal, Pakistan, and Papua New Guinea. In India, the incidence of this disease varies from 4-46% with high morbidity and mortality. Methods: In this cross-sectional study at a tertiary care hospital in Kolkata, India we analysed ferritin blood levels along with different demographic and laboratory test parameters of 60 suspected scrub typhus patients who were also scrub typhus IgM antibody positive during a one-year study period. Results: It was found that serum ferritin levels were unusually high in 21-40 years age group patients along with mildly increased urea and creatinine levels. Other important findings were below 40 years of age males were mostly affected, but above 40 years of age, females were generally affected. Haemoglobin and platelet levels were normal in all age groups. Although WBC count and neutrophils were normal in the 21-40 years age group, in other age groups increased levels were observed. CRP, SGPT, and SGOT levels were uniformly high above 20 years of age. Electrolytes were mildly decreased. Conclusions: It appears that oxidative stress-induced acute kidney injury may be an important reason for the rising ferritin levels in the 21-40 years age group. These important findings may be helpful to clinicians in management of these patients.

A case of Schnitzler syndrome with unusual immunoglobulin Agammopathy exacerbated by COVID-19 infection.

Schnitzler syndrome (SchS) is a rare autoinflammatory disease characterized by chronic urticarial rash and monoclonal immunoglobulin M (IgM) or IgG gammopathy. Viruses, including COVID-19, activate the innate immune system, therefore SchS, in which the innate immune system is improperly activated, is hypothesized to be exacerbated by viral infection. However, there were no reported SchS cases exacerbated by any viral infection. Here, we report a SchS case with an unusual IgA gammopathy manifested and exacerbated by COVID-19 infection. This report advocates the need for recognizing unusual cases of SchS with monoclonal IgA, and following up on paraprotein like IgA even when it is initially undetectable in cases with SchS symptoms. We also hypothesize that existing autoinflammatory diseases may be exacerbated by COVID-19 infection in the case of a combination of these diseases.

A study of the immunomodulatory effects of coconut oil extract in broilers experimentally infected with velogenic Newcastle disease virus.

This study aims to evaluate the immunomodulatory effects of coconut oil extract (COE) in broilers experimentally infected with velogenic Newcastle disease virus (vNDV). A total of 150 broiler birds (day-old) were equally divided into five study groups i.e., negative control, positive control, COE-1, COE-2, and COE-3. On day 10, broilers of groups COE-1, COE-2, and COE-3 were supplemented with 1, 2, and 3 mL of COE respectively per liter of drinking water for 15 days. On day 13, 0.1 mL/bird (10-5.25 ELD50) of vNDV was inoculated in broilers of positive control, COE-1, COE-2, and COE-3 groups intramuscularly. During this study, growth performance, morbidity, and mortality rates of each study group were recorded. The antibody titer against NDV was determined on days 7, 14, 21, 28, and 35. The levels of immunoglobulins (IgY and IgM) were also determined on the 7th, 14th, and 21st days post-sheep red blood cells (SRBCs) inoculation. On day 33, avian tuberculin was injected between the 1st and 2nd toes of the left side (intradermally) to measure lymphoproliferative responses. On day 35, the phagocytic activity in the blood was assessed through a carbon clearance assay by injecting carbon black ink into the right-wing vein. The visceral organs having gross lesions were also collected for histopathology. The COE significantly improved the growth performance, and lowered the morbidity and mortality rates of broilers. There was a significant rise in antibody titers against NDV and levels of IgY and IgM antibodies against SRBC in COE-supplemented broilers. The lymphoproliferative response and phagocytic activity were also enhanced. Among COEsupplemented groups, the broilers of the COE-3 group showed a significant increase in growth performance and boosted immune defense. Coconut oil extract has the potential to boost the growth performance and immune status of broilers. It can be used effectively as a feed additive and alternative to antibiotics to prevent the spread of infectious poultry pathogens.

ADAPTOGENIC EFFECTS OF PANAX GINSENG PLANT EXTRACT ON IMMUNE MODULATION IN LAYERS AGAINST SALMONELLA ENTERITIDIS

Panax ginseng, a traditional medicinal herb known for its adaptogenic properties, has garnered significant attention for its potential role in immune modulation and disease prevention. In this study, we investigate the adaptogenic effects of Panax ginseng on immune modulation in layers against Salmonella Enteritidis. This randomized control trial was conducted at Zarrar Shaheed Road, Lahore Cantt from January 2023 to October 2023. A total of 450 laying hens were included in this study. The laying hens were randomly assigned to different experimental groups to ensure unbiased representation and minimize confounding variables. The laying hens were separated into several experimental groups, including a benchmark group and one or more treatment groups receiving Panax ginseng supplementation. A total of 450 laying hens were included in the study, divided into five experimental groups: a control group (n = 90) and four treatment groups receiving varying doses of Panax ginseng supplementation (n = 90 each). Compared to the control group, hens receiving low, medium, and high portions of ginseng displayed elevated degrees of IgG and IgM antibodies. Specifically, the high-portion ginseng group demonstrated the most noteworthy mean values for both IgG (75 ± 18) and IgM (50 ± 12), indicating a vigorous invulnerable reaction. It is concluded that supplementation with Panax ginseng holds promise as a natural intervention for enhancing immune modulation and reducing pathogen load in laying hens challenged with Salmonella Enteritidis. Ginseng may serve as a valuable adjunct therapy in poultry production to mitigate infectious diseases and improve overall health outcomes.

Previous hepatitis E virus infection is associated with increased liver stiffness in patients with autoimmune hepatitis.

Autoimmune hepatitis (AIH) is a chronic, progressive liver disease that, in most cases, may require lifelong immunosuppression. Hepatitis E virus (HEV) is a leading cause of acute, typically self‑limited hepatitis worldwide, although immunocompromised patients may develop chronic hepatitis. We aimed to evaluate the impact of HEV seropositivity on the clinical course of AIH. The study involved a group of 374 adult patients with AIH (68% women; median [interquartile range] age, 34 [18-83] years; 38% with liver cirrhosis). Serum HEV immunoglobulin (Ig) G and IgM antibodies were measured by enzyme‑linked immunosorbent assay, liver fibrosis was assessed by liver stiffness measurement (LSM), and liver cirrhosis was confirmed with liver histology or LSM. Fifty‑five patients (15%) with AIH were HEV IgG‑positive. These patients were older (P <0.001), had higher body mass index, and higher value of LSM (both P <0.05). In a multivariable model including the levels of alanine aminotransferase and IgG, the HEV seropositive status was associated with an increased risk of advanced liver fibrosis with odds ratio of 3.69 (95% CI, 1.26-10.77; P = 0.02), as reflected by liver stiffness equal to or above 10.5 kPa. HEV IgG seropositivity was, however, not linked with the type of treatment or worse AIH outcome. Seroprevalence of HEV in the patients with AIH was lower than in the general population of Polish blood donors (43%). Patients with AIH and HEV IgG‑positive status seem to be at risk of more advanced liver fibrosis. However, the overall seroprevalence of HEV IgG is lower in patients with AIH than in blood donors in Poland.

Association between Pityriasis Rosea (PR) and HHV-6/HHV-7 Infection: Importance of Sample Selection and Diagnostic Techniques.

Recent studies have focused on the role of human herpesvirus 6 (HHV-6) and human herpesvirus 7 (HHV-7) in PR etiology with varying results. In our study, with the approach that the discrepancy between the results may be related to the different samples and techniques used, we aimed to clarify the etiology by examining tissue and plasma samples using molecular methods and evaluating the results together with serological parameters. Skin biopsies and plasma samples of twenty-five PR patients were tested to detect HHV-6 and HHV-7 DNA using calibrated quantitative real-time polymerase chain reaction (CQ RT-PCR). IgG and IgM antibodies against HHV-6 and HHV-7 were tested by enzyme-linked immunosorbent assay and indirect immunofluorescence. Of the patient group, 64% were positive for HHV-6 IgG without IgM positivity. HHV-6 DNA was present in seven tissue and ten plasma samples. HHV-7 positivity was 100% and 12% for IgG and IgM antibodies, respectively. HHV-7 DNA was detected in four tissue samples and one plasma sample. Patients with HHV-7 DNA-positive plasma and tissue samples had also HHV-7 IgM antibodies. In conclusion, our results seem to support the role of HHV-6/HHV-7 in the etiology of PR. To clarify the etiology of PR and avoid confusion, the collection of different biological materials simultaneously and the usage of CQ RT-PCR as a diagnostic technique are recommended.

Multiple trait comparison and global intestine transcriptional provide new insights into bases of heterosis in hybrid tilapia (Oreochromis niloticus × Oreochromis aureus)

Heterosis has been utilized in aquaculture for many years, yet its molecular basis remains elusive. Therefore, a comprehensive analysis of heterosis was conducted by comparing growth, digestion and biochemistry indices, as well as the intestinal gene expression profiles of Nile tilapia, blue tilapia and their hybrids. The results revealed that hybrid tilapia demonstrated an enhanced growth traits and elevated digestive enzyme activity compared to Nile and blue tilapia. Additionally, the hybrid tilapia displayed superior antioxidants and non-specific immune levels, with increased levels of catalase (CAT), alkaline phosphatase (AKP), acid phosphatase (ACP), glutathione (GSH), superoxide dismutase (SOD), total antioxidant capacity (TAOC), lysozyme, and immunoglobulin M (IgM) relative to Nile and blue tilapia. Moreover, 3392, 2470 and 1261 differentially expressed genes (DEGs) were identified in the intestinal tissues when comparing Nile tilapia to blue tilapia, hybrid tilapia to blue tilapia, and hybrid tilapia to Nile tilapia. Upon classifying the differentially expressed genes (DEGs), non-additively expressed DEGs accounted for 68.1 % of the total DEGs, with dominant and over-dominant expressed DEGs comprising 63.7 % and 4.4 % in the intestines, respectively. These non-additively expressed DEGs were primarily associated with metabolic, digestive, growth, and developmental pathways. This enrichment enhances our comprehension of the molecular underpinnings of growth heterosis in aquatic species.

Seromolecular study on the prevalence and risk factors of Toxoplasma gondii infection in pregnant women referred to a gynecology hospital in Urmia, northwest part of Iran in 2022

Toxoplasmosis is a frequent infection among the human population. The infection can cause devastating complications for the fetus during pregnancy. The present study aimed to determine the serological and molecular prevalence of the infection and molecular characterization of Toxoplasma gondii isolates among pregnant women referred to Kowsar Hospital, Urmia, Iran. In a cross-sectional study, 340 blood samples were collected from pregnant women referred to Kowsar Hospital, Urmia, Iran from May to July 2022. Anti-T. gondii IgG and IgM seropositivity were determined by enzyme-linked immunosorbent assay. PCR was carried out by targeting the GRA6 gene of the parasite on all patients’ buffy coats. Anti-T. gondii IgG and IgM antibodies were positive in two (0.6%) women, and 101 (29.7%) women had anti-T. gondii IgG and 70.3% were seronegative. PCR was positive in two IgM-positive women, and both isolates belonged to T. gondii carrying the GRA6 allele of lineage I. The risk of infection was significantly higher in women who had constant contact with cats and soil, and who were residents of rural areas. The two IgM-positive women were asymptomatic regarding acute toxoplasmosis. According to the results of the present study, the prevalence of toxoplasmosis in pregnant women in Urmia is similar to its prevalence in other areas in northwestern Iran, and despite the low prevalence of acute infection, it should not be ignored.

IgM anti-GM2 antibodies in patients with multifocal motor neuropathy target Schwann cells and are associated with early onset.

Multifocal motor neuropathy (MMN) is a rare, chronic immune-mediated polyneuropathy characterized by asymmetric distal limb weakness. An important feature of MMN is the presence of IgM antibodies against gangliosides, in particular GM1 and less often GM2. Antibodies against GM1 bind to motor neurons (MNs) and cause damage through complement activation. The involvement of Schwann cells (SCs), expressing GM1 and GM2, in the pathogenesis of MMN is unknown. Combining the data of our 2007 and 2015 combined cross-sectional and follow-up studies in Dutch patients with MMN, we evaluated the presence of IgM antibodies against GM1 and GM2 in serum from 124 patients with MMN and investigated their binding to SCs and complement-activating properties. We also assessed the relation of IgM binding and complement deposition with clinical characteristics. Thirteen out of 124 patients (10%) had a positive ELISA titer for IgM anti-GM2. Age at onset of symptoms was significantly lower in MMN patients with anti-GM2 IgM. IgM binding to SCs correlated with IgM anti-GM2 titers. We found no correlation between IgM anti-GM2 titers and MN binding or with IgM anti-GM1 titers. IgM binding to SCs decreased upon pre-incubation of serum with soluble GM2, but not with soluble GM1. IgM anti-GM2 binding to SCs correlated with complement activation, as reflected by increased C3 fixation on SCs and C5a formation in the supernatant. Circulating IgM anti-GM2 antibodies define a subgroup of patients with MMN that has an earlier onset of disease. These antibodies probably target SCs specifically and activate complement, similarly as IgM anti-GM1 on MNs. Our data indicate that complement activation by IgM antibodies bound to SCs and MNs underlies MMN pathology.

Evaluation of the efficacy of MONTANIDE™ GR01, a new adjuvant for feed-based vaccines, on the immune response and protection against Streptococcus agalactiae in oral vaccinated Nile tilapia (Oreochromis niloticus) under laboratory and on-farm conditions

Streptococcosis, an emerging infectious disease caused by Streptococcus agalactiae, has had adverse effects on farmed tilapia. Several vaccines have been developed to prevent this disease and induce a specific immune response against S. agalactiae infection. In this study the use of MONTANIDE™ GR01, a new adjuvant for oral vaccination, was optimized for use in tilapia under laboratory and field studies. In the laboratory trial the immune response and protective efficacy of two doses of MONTANIDE™ GR01, 20 % (w/w) and 2 % (w/w), included into the feed-based adjuvanted vaccines were assessed comparatively. Following immunization, the innate immune parameters studied in serum, including lysozyme, myeloperoxidase, catalase and glutathione peroxidase activity, were all increased significantly. Furthermore, specific IgM antibodies against S. agalactiae were induced significantly in serum post-vaccination, with higher levels observed in both groups that received the feed-based adjuvanted vaccine. Under both injection and immersion challenge conditions, the relative percent survival for the feed-based adjuvanted vaccine groups ranged from 78 % to 84 %. Following use of the low dose concentration of MONTANIDE™ GR01 for oral vaccination of tilapia in cage culture systems, several innate immune parameters were effectively enhanced in the immunized fish. Similarly, the levels of specific IgM antibodies in the serum of feed-based vaccinated fish were significantly enhanced, reaching their highest levels 2–5 months post-vaccination. Cytokines associated with innate and adaptive immunity were also examined, and the expression levels of several genes showed significant up-regulation. This indicates that both cellular and humoral immune responses were induced by the feed-based adjuvanted vaccine. The economic impact of a feed-based adjuvanted vaccine was examined following vaccination, considering the growth performance and feed utilization of the fish. It was found that the Economic Performance Index and Economic Conversion Ratio were unaffected by vaccination, further demonstrating that there are no negative impacts associated with administering a feed-based vaccine to fish. In conclusion, the data from this study indicate that MONTANIDE™ GR01 is a highly valuable adjuvant for oral vaccination, as demonstrated by its ability to induce a strong immune response and effectively prevent streptococcal disease in Nile tilapia.

Prognostic value of serum immunoglobulin M levels in patients with acute coronary syndrome

Background and aimsThe immuno-inflammatory response is a crucial early step in the development of acute coronary syndrome (ACS). In this study, we investigated whether immunoglobulin M (IgM) in the body's initial immune response can predict the prognosis of patients with ACS. MethodsThis prospective cohort study enrolled 1556 ACS patients at Beijing Hospital between March 2017 and October 2020. All patients underwent coronary angiography (CAG). The serum IgM concentration and biochemical indicators were evaluated prior to CAG. The primary endpoint was the composite endpoint of major adverse cardiovascular and cerebrovascular events (MACCEs). Multivariate Cox proportional hazards models was used to explore the association between IgM levels and the endpoint. ResultsThe average serum IgM levels of the population was 61.3 (42.6–88.4) mg/dL. During the median follow-up period of 55 months, 150 MACCEs occurred. Kaplan-Meier analysis showed that low serum IgM levels were associated with occurrence of MACCEs (log-rank p = 0.009). Univariate Cox proportional hazards models showed that low serum IgM (≤78.05 mg/dL) was associated with MACCEs (hazard ratio (HR) 1.648, 95 % confidence interval (CI): 1.129–2.406, p = 0.010). In patients with IgM ≤78.05 mg/dL, the HR for partially adjusted MACCEs events was 1.576 (95 % CI: 1.075–2.310) and 1.930 (95 % CI: 1.080–3.449) after adjusting for multiple covariates. The subgroup analysis showed that for patients in ≤24 BMI, never smoking and non-dyslipidemia subgroup, the lower serum IgM levels was significantly associated with the risk of MACCEs (pinteraction < 0.001, pinteraction = 0.037, pinteraction = 0.024, respectively). ConclusionsLow serum IgM levels was independently associated with MACCEs in ACS patients, especially for patients without obesity, smoking and dyslipidemia.

Asparaginase-specific basophil recognition and activation predict Asparaginase hypersensitivity in mice.

Asparaginase (ASNase) is a crucial part of acute leukemia treatment, but immune responses to the agent can reduce its effectiveness and increase the risk of relapse. Currently, no reliable and validated biomarker predicts ASNase-induced hypersensitivity reactions during therapy. We aimed to identify predictive biomarkers and determine immune cells responsible for anaphylaxis using a murine model of ASNase hypersensitivity. Our preclinical study uses a murine model to investigate predictive biomarkers of ASNase anaphylaxis, including anti-ASNase antibody responses, immune complex (IC) levels, ASNase-specific binding to leukocytes or basophils, and basophil activation. Our results indicate that mice immunized to ASNase exhibited dynamic IgM, IgG, and IgE antibody responses. The severity of ASNase-induced anaphylaxis was found to be correlated with levels of IgG and IgE, but not IgM. Basophils from immunized mice were able to recognize and activate in response to ASNase ex vivo, and the extent of recognition and activation also correlated with the severity of anaphylaxis observed. Using a multivariable model that included all biomarkers significantly associated with anaphylaxis, independent predictors of ASNase-induced hypersensitivity reactions were found to be ASNase IC levels and ASNase-specific binding to leukocytes or basophils. Consistent with our multivariable analysis, we found that basophil depletion significantly protected mice from ASNase-induced hypersensitivity reactions, supporting that basophils are essential and can be used as a predictive marker of ASNase-induced anaphylaxis. Our study demonstrates the need for using tools that can detect both IC- and IgE-mediated hypersensitivity reactions to mitigate the risk of ASNase-induced hypersensitivity reactions during treatment.

Changes in the avids of IgG antibodies to the S protein of SARS-CoV-2 after coronavirus infection in medical workers of a temporary infections hospital

BACKGROUND: The effector capabilities of humoral immunity are determined not only by the amount of specific antibodies produced in response to an antigenic effect, but also by their qualitative characteristics, which include avidity ― the total strength of binding to the antigen, which determines the duration and effectiveness of post-infectious immunity to SARS-CoV-2.&#x0D; AIM: Is a selective study of the quantity and avidity of IgG antibodies to SARS-CoV-2 over time among medical workers of a temporary infectious diseases hospital in Kazan ― convalescents of COVID-19, during the period from July 2020 to July 2021.&#x0D; MATERIALS AND METHODS: Determination of IgG to the S antigen of SARS-CoV-2 by ELISA was carried out using the test system SARS-CoV-2-IgG quantitative-ELISA-BEST (Vector-Best, Russia) and expressed in BAU/ml (binding antibody units). Antibody avidity was determined using a 4.0 M urea solution and expressed as avidity indices. 1, 4 and 7 months after COVID-19 asymptomatic (n=34); mild severity (n=42); moderate severity (n=29); reinfected (n=34). When statistically processing the data, descriptive statistics methods and the Wilcoxon matched data test were used. Differences were considered significant at p 0.05.&#x0D; RESULTS: IgG avidity to SARS-CoV-2 depended on the severity of COVID-19. The highest rates of avidity indices were found in the group of those who had a moderate form of COVID-19. If in mild and asymptomatic forms there was a parallel decrease in avidity indices and IgG titer, then in moderate forms an increase in antibody titer was accompanied by a decrease in their avidity 4 months after the infection. 7 months after seroconversion, the IgG level decreased almost twofold, both in mild, asymptomatic and moderate forms. In the group of medical workers who had COVID-19 repeatedly, the initially low levels of avidity indices and antibody titers increased in parallel, while avidity indices after 7 months did not decrease, but remained high. Differences in avidity indices determined the subsequent formation of different trends in the development of the humoral immune response, which were mainly characterized by an uneven decrease in IgG and persistence of IgM antibodies for more than 1 month.&#x0D; CONCLUSIONS: The research results expand the understanding of the mechanisms of formation of the humoral immune response and the avidity of IgG antibodies against SARS-CoV-2 in the risk group ― medical workers. The level of humoral immunity decreases in the first six months and varies depending on the severity of COVID-19. The data obtained can be used to identify categories of increased risk of SARS-CoV-2 infection among healthcare workers, make decisions about immunorehabilitation and revaccination against COVID-19.

Epidemiology of Mycoplasma pneumoniae in children with acute respiratory infections in Hangzhou during January 2021 to June 2023

Abstract Objectives Mycoplasma pneumoniae (MP) is known to be a common pathogen causing human respiratory infections. On December 7, 2022, the Chinese government announced 10 new measures of Prevention and Control of COVID-19, marking the onset of the post-COVID-19 era. This study aimed to investigate the epidemiological characteristics of MP infections among children from January 2021 to June 2023. Methods Children with respiratory tract infection were enrolled in the study with fever and one or more respiratory symptoms. A serological diagnosis was confirmed with MP IgM antibodies. Results A total of 18,763 patients were enrolled, of whom 4,867 cases were MP-positive, resulting in a positivity rate of 25.9 %. The MP positivity rate increased annually, with 18.6 , 26.7, and 33.2 % in 2021, 2022, and 2023, respectively. The main disease type of MP infection was Mycoplasma pneumoniae pneumonia (MPP), with 74.0 , 87.8, and 86.4 % in 2021, 2022, and 2023, respectively. Higher positivity rates were concentrated in children aged 6 years and older, and the positivity rate in children under 1 year of age in 2023 is the largest increase among all age groups. Conclusions The positivity rate of MP increased significantly after the adjustment of COVID-19 prevention and control in China, and the most significant increase was seen in the infant group. Effective prevention and control measures should be implemented to reduce the prevalence of MP infection among children aged 6 years older and the infant group (&lt;1 year).

Comparison of estimated blood loss during living kidney transplantation according to the number of double-filtration plasmapheresis

BackgroundPlasmapheresis is an important preoperative desensitization treatment for ABO-incompatible living kidney transplantation. However, in cases with plasma exchange therapy (PET), it is necessary to consider the risks of perioperative bleeding and healthcare economic costs. This study investigated the association between intraoperative blood loss and the frequency of preoperative double-filtration plasmapheresis (DFPP) and explored the correlation between DFPP frequency and coagulation factors. Furthermore, the study examined the incidence of perioperative bleeding complications.MethodsWe enrolled 294 patients (205 men and 89 women) who underwent living kidney transplantation at our institution between January 2020 and March 2023, without PET or with only DFPP performed as PET. A single dose of rituximab (200 mg) was administered to ABO-incompatible living kidney transplant patients within 7 days before transplantation. In these patients, PET was performed until anti-blood group IgG and IgM antibody titers were reduced to 32 times or less.ResultsThe intraoperative blood loss increased in accordance with the DFPP sessions. The amount of bleeding significantly increased when DFPP was performed ≥ 2 sessions. Considering this, we initiated serum fibrinogen level measurements from the middle of the study and observed that serum fibrinogen levels decreased in correlation with the number of DFPP sessions. Fibrinogen levels dropped to critical levels (< 100 mg/dL) after three sessions of DFPP. Within the entire cohort, four patients (1.4%) underwent post-transplantation hematoma removal surgery, and among them, three had received DFPP before transplantation.ConclusionsThe number of DFPP procedures was associated with the amount of bleeding and serum fibrinogen levels during living kidney transplantation.

A declining trend of hepatitis A and hepatitis E at tertiary care hospital in South Gujarat

Objectives: Hepatitis A virus (HAV) and Hepatitis E virus (HEV) both are spread through the fecal-oral route and cause acute viral hepatitis (AVH) and pose a major public health problem in India. This study was done to find out the proportion of positivity of HAV and HEV in patients with AVH and its seasonal trend. Materials and Methods: A retrospective study was carried out at Surat Municipal Institute of Medical Education and Research Medical College, Department of Microbiology, Surat, Gujarat. Result of 3615 blood samples of suspected AVH patients of the past 5 years (January 2018–December 2022) were taken from hospital data records. The enzyme-linked immunosorbent assay method was used to test serum samples for immunoglobulin M (IgM) HAV and IgM HEV antibodies for HAV and HEV, respectively. All samples were evaluated for liver function as well. Results: The positivity of HAV and HEV was 15.13% and 10.26%, respectively. The coinfection rate was 2.07%. HAV and HEV both affected males more than females. Among pregnant females, HEV infection had more positivity (6.77%) than HAV, which had 1.08% positivity. HAV and HEV infections had a seasonal trend, with the highest infection rate in the monsoon. Conclusion: The declining trend of cases of HAV and HEV was found in Surat city of south Gujarat which indicates increased awareness about hepatitis among people and better public health management by the civic authorities.

Comparison of Mycoplasma pneumoniae infection in children admitted with community acquired pneumonia before and during the COVID-19 pandemic: a retrospective study at a tertiary hospital of southwest China.

The COVID-19 pandemic has notably altered the infection dynamics of various pathogens. This study aimed to evaluate the pandemic's impact on the infection spectrum of Mycoplasma pneumoniae (M. pneumoniae) among children with community acquired pneumonia (CAP). We enrolled pediatric CAP patients admitted to a tertiary hospital in southwest China to compare the prevalence and characteristics of M. pneumoniae infections before (2018-2019) and during (2020-2022) the COVID-19 pandemic. Detection of M. pneumoniae IgM antibodies in serum were conducted using either indirect immunofluorescence or passive agglutination methods. The study included 1505 M. pneumoniae-positive and 3160 M. pneumoniae-negative CAP patients. Notable findings were the higher age and frequency of pneumonia-associated symptoms in M. pneumoniae-positive patients, alongside a lower male proportion and fewer respiratory co-infections. The year 2019 saw a notable increase in M. pneumoniae infections compared to 2018, followed by a decline from 2020 to 2022. The COVID-19 pandemic period witnessed significant alterations in age distribution, male proportion, and co-infections with specific pathogens in both M. pneumoniae-positive and negative patients. The M. pneumoniae infections were predominantly seasonal, peaking in autumn and winter during 2018 and 2019. Although there was a sharp drop in February 2020, the infection still peaked in cold months of 2020 and 2021. However, the typical seasonal pattern was nearly absent in 2022. The COVID-19 pandemic has markedly changed the infection landscape of M. pneumoniae in pediatric CAP patients, with shifts observed in infection rates, demographic profiles, co-infections, and seasonal patterns.