Antibodies, Viral/immunology* ; COVID-19/immunology* ; Humans ; Immunoglobulin G/immunology* ; Immunoglobulin M/immunology* ; SARS-CoV-2/immunology*

AIMTo explore the role of humoral immunity in the pathophysiological process of freezing injury and the possible immune interference in the preventation and treatment of frostbite.

METHODSSevere experimental freezing injury model was made in Wistar rats( n = 20). The concentration of three types of immunoglobulin (IgG, IgA and IgM), two types of complement components (C3 and C4), and circulating immune complex (CIC) were measured respectively before and at 4h, 1d, 3d, and 5d after frostbite. At the same time, the tissue immune complex (TIC) in skeletal muscle and the contents of the red blood cell immune complex (RBC-IC) were also observed and then was the red blood cell immune adherence activity (RCIA).

RESULTSSerum IgG concentration decreased rapidly to the lowest level at 4 h after frostbite IgA concentration dropped to the nadir on 1 day after freezing. Decreases of both immunoglobulins were maintained during the 5 days after frostbite. The fate of both C3 and C4 were the same as those immunoglobulins. Freezing had rather less effect on IgM level. CIC concentration in serum, expressed as the percent of prefreezing increased rapidly and to the zenith on the 3 days post-freezing. By immunofluorescence microscopy, thin continuous linear pattern (IgG) was demonstrated along the SM on the first day post-freezing. Granular and nodular deposits (IgG) appeared along the SM as the time proceeded after frostbite. RBC-IC contents, expressed as the erythrocyte IC rosette rate, increased significantly and to the zenith on the 3 d post-freezing, while RCIA depressed to the nadir at the same time.

CONCLUSIONThe freezing frostbite is an immune complex related disease which have not been reported by others before.

Animals ; Antigen-Antibody Complex ; analysis ; immunology ; Frostbite ; blood ; immunology ; Immunoglobulin A ; immunology ; Immunoglobulin G ; immunology ; Immunoglobulin M ; immunology ; Immunoglobulins ; immunology ; Male ; Rats ; Rats, Wistar

OBJECTIVETo evaluate two commercial anti-hepatitis E virus (HEV) IgM kits used for differential diagnosis of acute enteric viral hepatitis.

METHODSThe kit for IgM capture assay, was produced with a recombinant HEV structural protein protecting primates against experimental infection by different HEV genotypes, while the other kit for indirect ELISA was produced with recombinant structural proteins from different HEV genotypes. The serum specimens were taken from 241 cases with a confirmed or presumptive diagnosis of hepatitis A and 74 cases with a confirmed or presumptive diagnosis of hepatitis E.

RESULTSThe sensitivity and specificity of the IgM capture assay kit were 97% and 100%, respectively, and the corresponding values for the other kit were 70% and 78%, respectively.

CONCLUSIONThe IgM capture assay kit has higher sensitivity and specificity in diagnosing acute enteric viral hepatitis E.

Diagnosis, Differential ; Hepatitis E ; diagnosis ; immunology ; Humans ; Immunoglobulin M ; blood ; immunology ; Reagent Kits, Diagnostic ; Sensitivity and Specificity

Acetaldehyde ; metabolism ; Alcoholics ; Alcoholism ; blood ; immunology ; Antibodies, Anti-Idiotypic ; Humans ; Immunoglobulin A ; immunology ; Immunoglobulin G ; immunology ; Immunoglobulin M ; immunology ; Protein Processing, Post-Translational

The changes in serum levels of immunoglobulins G, M and A of dairy and beef calves of well-managed herds were monitored from birth to 14 days post partum using single radial immunodiffusion. Serum levels of all three immunoglobulin classes reached its peak at 24 hours in both groups of calves after birth, at which time there were very high levels of each immunoglobulin present. The mean IgM and IgA levels of the two groups became same at 6 days and 8 days of age, respectively but the mean IgG level of beef calves was approximately twice that of dairy calves throughout the experiment.
Animals ; Animals, Newborn ; Cattle/*immunology ; Female ; Immunodiffusion/veterinary ; Immunoglobulin A/blood ; Immunoglobulin G/blood ; Immunoglobulin M/blood ; Immunoglobulins/*blood ; Male ; Pregnancy

OBJECTIVETo study the possible role of human β-defensins 1 (Hbd-1) and immunoglobulins A, G and M (IgA, IgG and IgM) in the development of recurrent pneumonia by measuring serum concentrations of the above indexes in infants with recurrent pneumonia and healthy infants.

METHODSSerum samples were obtained from 35 healthy children and 35 children aged from 2 to 24 months with recurrent pneumonia. Serum Hbd-1 concentration was measured using ELISA. Serum IgA, IgG and IgM concentrations were measured by immunonephelometry. The correlation of hBD-1 with IgA, IgG and IgM was evaluated.

RESULTSThe serum concentration of hBD-1 in infants with recurrent pneumonia (14±11 μg/mL) was significantly lower than in controls (18±11 μg/mL) (P<0.05), as was the serum concentration of IgA in infants with recurrent pneumonia (1.3±0.6 g/L vs 1.5±0.8 g/L; P<0.05). The serum concentration of IgG in infants with recurrent pneumonia was also significantly lower than in controls (9±3 g/L vs 13±5 g/L; P<0.05). There were no linear relationships between serum Hbd-1 and IgA, IgG and IgM (P>0.05).

CONCLUSIONSThe serum levels of hBD-1, IgA and IgG decrease in infants with recurrent pneumonia, suggesting disorders in the immune defensive function of the respiratory tract, and this may be one of the immunity related reasons for recurrent pneumonia in infants. It is of great clinical value to measure serum levels of Hbd-1, IgA, IgG and IgM in infants with recurrent pneumonia.

Female ; Humans ; Immunoglobulin A ; blood ; Immunoglobulin G ; blood ; Immunoglobulin M ; blood ; Immunoglobulins ; blood ; Infant ; Male ; Pneumonia ; immunology ; Recurrence ; beta-Defensins ; blood

Aged ; Humans ; Immunoglobulin M ; Liver Failure, Acute ; etiology ; Male ; Multiple Myeloma ; complications ; immunology

OBJECTIVETo establish the method of enzyme-linked immunosorbent assay (ELISA) for measuring human IgM autoantibody to folate receptor.

METHODSFolate receptor was extracted and purified from the healthy woman placenta. The protein was coated on 96-well plates with a concentration of 5 ng/Μl. Goat monoclonal antibody was used for detecting antibody. Pooled plasma from healthy donors was used to plot the standard curve and the IgM concentration of pooled plasma was defined as 1. We set up an ELISA procedure to measure human IgM autoantibody to folate receptor. The sensitivity, precision, and stability of the method were evaluated. Further, the folate receptor and bovine folate-binding protein were used as the antigen, respectively, to determine the autoantibody levels in 24 healthy individuals and 20 individuals once gave birth to baby with neural tube defects.

RESULTSThe measuring range of the method was from 6.25 × 10⁻⁴ to 8.00 × 10⁻². The lowest IgM level that can be detected was 3.12 × 10⁻⁴. The inter-assay coefficients of variations for samples with high, medium, and low IgM levels were 6.61%,3.50%, and 5.12%, respectively. The intra-assay coefficients of variations were 4.54%, 5.49%, and 5.44%, respectively. The stability test results were considered within acceptable limits. The data from folate receptor-ELISA was significantly higher than that from bovine folate binding protein-ELISA, both in the healthy group (t=-11.9, P<0.001) and in the neural tube defect group (t = 7.35, P<0.001).

CONCLUSIONSThe folate receptor-ELISA method for measuring human IgM autoantibody to folate receptor was successfully established. The method is sensitive, repeatable, and stable.

Autoantibodies ; blood ; Enzyme-Linked Immunosorbent Assay ; methods ; Folate Receptor 2 ; immunology ; Humans ; Immunoglobulin M ; blood

OBJECTIVES: To investigate the change in the distribution of memory B cell subsets in children with frequently relapsing nephrotic syndrome (FRNS) during the course of the disease. METHODS: A total of 35 children with primary nephrotic syndrome (PNS) who attended the Department of Pediatrics of the Affiliated Hospital of Xuzhou Medical University from October 2020 to October 2021 were enrolled as subjects in this prospective study. According to the response to glucocorticoid (GC) therapy and frequency of recurrence, the children were divided into two groups: FRNS (n=20) and non-FRNS (NFRNS; n=15). Fifteen children who underwent physical examination were enrolled as the control group. The change in memory B cells after GC therapy was compared between groups, and its correlation with clinical indicators was analyzed. RESULTS: Before treatment, the FRNS and NFRNS groups had significantly increased percentages of total B cells, total memory B cells, IgD⁺ memory B cells, and IgE⁺ memory B cells compared with the control group, and the FRNS group had significantly greater increases than the NFRNS group (P<0.05); the FRNS group had a significantly lower percentage of class-switched memory B cells than the NFRNS and control groups (P<0.05). After treatment, the FRNS and NFRNS groups had significant reductions in the percentages of total B cells, total memory B cells, IgM⁺IgD⁺ memory B cells, IgM⁺ memory B cells, IgE⁺ memory B cells, IgD⁺ memory B cells, and IgG⁺ memory B cells (P<0.05) and a significant increase in the percentage of class-switched memory B cells (P<0.05). The FRNS group had a significantly higher urinary protein quantification than the NFRNS and control groups (P<0.05) and a significantly lower level of albumin than the control group (P<0.05). In the FRNS group, urinary protein quantification was negatively correlated with the percentage of class-switched memory B cells and was positively correlated with the percentage of IgE⁺ memory B cells (P<0.05). CONCLUSIONS Abnormal distribution of memory B cell subsets may be observed in children with FRNS, and the percentages of IgE⁺ memory B cells and class-switched memory B cells can be used as positive and negative correlation factors for predicting recurrence after GC therapy in these children.
Child ; Humans ; B-Lymphocyte Subsets/metabolism* ; Immunoglobulin E ; Immunoglobulin M ; Nephrotic Syndrome/immunology* ; Prospective Studies ; Glucocorticoids/therapeutic use*

The emerging of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) caused COVID-19 pandemic. The first case of COVID-19 was reported at early December in 2019 in Wuhan City, China. To examine specific antibodies against SARS-CoV-2 in biological samples before December 2019 would give clues when the epidemic of SARS-CoV-2 might start to circulate in populations. We obtained all 88,517 plasmas from 76,844 blood donors in Wuhan between 1 September and 31 December 2019. We first evaluated the pan-immunoglobin (pan-Ig) against SARS-CoV-2 in 43,850 samples from 32,484 blood donors with suitable sample quality and enough volume. Two hundred and sixty-four samples from 213 donors were pan-Ig reactive, then further tested IgG and IgM, and validated by neutralizing antibodies against SARS-CoV-2. Two hundred and thirteen samples (from 175 donors) were only pan-Ig reactive, 8 (from 4 donors) were pan-Ig and IgG reactive, and 43 (from 34 donors) were pan-Ig and IgM reactive. Microneutralization assay showed all negative results. In addition, 213 screened reactive donors were analyzed and did not show obviously temporal or regional tendency, but the distribution of age showed a difference compared with all tested donors. Then we reviewed SARS-CoV-2 antibody results from these donors who donated several times from September 2019 to June 2020, partly tested in a previous published study, no one was found a significant increase in S/CO of antibodies against SARS-CoV-2. Our findings showed no SARS-CoV-2-specific antibodies existing among blood donors in Wuhan, China before 2020, indicating no evidence of transmission of COVID-19 before December 2019 in Wuhan, China.
Humans ; Antibodies, Viral ; Blood Donors ; China/epidemiology* ; COVID-19/immunology* ; Immunoglobulin G ; Immunoglobulin M ; Pandemics ; SARS-CoV-2