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@#Objective To develop and verify an indirect ELISA method for determination of specific IgG antibody of rhesus monkey serum against SARS-CoV-2 variant strain. Methods An indirect ELISA method for the determination of specific IgG antibody was developed using inactivated SARS-CoV-2 Beta variant strain inactivated vaccine as coating antigen,and optimized for the coating antigen concentration(1,2 and 4 μg/mL),dilution of serum(1∶800～1∶12 800),blocking solution(PBST containing 1% BSA,2% BSA,1% skim milk,2% skim milk and 1% BSA + 1% skim milk),blocking time(30,60 and 90 min),dilution of secondary antibody(1∶5 000,1∶10 000,1∶15 000 and 1∶20 000),incubation time of serum and secondary antibody(30,60 and 90 min),and TMB reaction time(5,10,15,20,25 and 30 min). 60 negative serum samples of rhesus monkeys were detected by the developed method,and the negative and positive critical values were determined. The sensitivity and precision of the methodology were verified. In addition,the specific IgG antibody and neutralizing antibody against SARS-CoV-2 Beta variant strain in 44 serum samples of rhesus monkey were detected by the developed method and microneutralization method,and the correlation and consistency between the two methods were compared. Results The optimum detection conditions were determined:the coating antigen concentration was 1 μg/mL;the blocking solution was PBST containing 1% skim milk,and the blocking time was 30 min;the serum samples to be tested were diluted to 1∶1 600 and incubated for 90 min,and the secondary antibody was diluted to 1∶10 000 and incubated for 30 min;the color development time of substrate was 25 min. The positive critical value and negative critical value of the method was 0. 093 and 0. 084 respectively,and the detection values between them were judged as suspicious. The dilution of5 positive serum samples that showed positive results was 1∶51 200;the coefficients of variation(CVs)of precision were all less than 15%. There was a strong correlation between IgG antibody titer and neutralizing antibody level in the 44 rhesus monkey serum samples(r = 0. 858 0,P < 0. 000 1);the total coincidence rate of the two methods was 90. 9%,the positive coincidence rate was 93. 6%,and the negative coincidence rate was 84. 6%;the consistency test Kappa value was 0. 783 8(95% CI:0. 586 5～0. 981 0). Conclusion The developed indirect ELISA method for eletermination of specific IgG antibody against SARS-CoV-2 Beta variant strain in rhesus monkey serum has good sensitivity and precision,and has strong consistency with microneutralization method,which can be used for the determination of IgG antibody in rhesus monkey serum.
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Objective:To investigate the correlation between food-specific IgG (sIgG) antibodies and phenotypes of chronic spontaneous urticaria (CSU) .Methods:Serum samples were collected from outpatients with active CSU, symptomatic dermographism (SD) , or acute urticaria (AU) , and healthy controls from 5 third-grade class-A hospitals such as the First Hospital of China Medical University between April 2014 and March 2015. Enzyme-linked immunosorbent assay was conducted to detect serum levels of 90 food-sIgG antibodies and total IgE, Western blot analysis to detect levels of 20 allergen-specific IgE antibodies, and chemiluminescent microparticle immunoassay to detect levels of anti-thyroid peroxidase IgG antibodies and anti-thyroglobulin IgG antibodies. Comparisons of normally distributed quantitative data between two groups and among several groups were performed by t test and one-way analysis of variance, respectively; comparisons of non-normally distributed quantitative data between two groups were performed by Mann-Whitney U test; for comparisons of proportions, chi-square test and Fisher′s exact test were used. Results:A total of 248 patients with CSU, 22 with SD, 15 with AU and 13 healthy controls were recruited. The cut-off level for sIgG positivity was 100 U/ml (at least 2+) , and the positive rate of food-sIgG antibodies was slightly higher in the patients with CSU (176/248, 70.97%) , SD (15/22, 68.18%) and AU (11/15) than in the healthy controls (7/13; χ2 = 1.80, P = 0.615) . Among the 248 CSU patients, the proportion of patients with family history of allergic diseases was significantly higher in the sIgG-positive group (71/176, 40.34%) than in the sIgG-negative group (19/72, 26.39%; χ2 = 4.30, P = 0.042) , while no significant difference was observed in the 1-day urticaria activity score (UASday) between the two groups ( Z = 0.18, P = 0.859) . Totally, 177 CSU patients completed 12- to 40-week treatment; their condition could be completely controlled by second-generation H1-antihistamines, and there was no significant difference in the required dosage of second-generation H1-antihistamines between the sIgG-positive group (128 cases) and sIgG-negative group (49 cases; Z = -1.06, P = 0.298) . Conclusions:The prevalence of family history of allergic diseases was relatively high in food-sIgG-positive patients with CSU. However, food-sIgG could not be used as an indicator to reflect the disease activity of CSU and treatment response.
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Objective To observe the food intolerance of irritable bowel syndrome with diarrhoea(IBS-D) patients and healthy physical examinees and the clinical effect of the treatment of IBS-D food rejectingtrend.Methods Sixty-eight cases IBS-D patients meeting the diagnostic criteria of RomeⅢ were selected and 40 cases of healthy as control group,tested 14 kinds of food specific IgG antibody by enzyme-linked immunosorbent assay,treated the IBS-D patients with food intolerance for 12 weeks by the application of food rejectingtrend and observed the change of main symptoms.Results Among the 68 cases of IBS-D patients,55 cases had at least one of food intolerance,the positive rate was 80.88%;the control group had 13 cases of food intolerance,the positive rate was 32.50%,the difference between the two groups was statistically significant(χ2=25.28,P<0.01).The food with the highest positive rates of two groups were both wheat,egg white/egg yolk,milk and soybean.After 12 weeks of diet treatment,the total score of the symptoms of IBS-D patients decreased from (8.25±2.97) points to (3.13±3.52) points(t=11.107,P<0.01),self scores of the degree 0and frequency of abdominal pain,frequency of diarrhea,degree of abdominal distension,stool shape and general feelings of distress were significantly improved compared with that before treatment(t=12.429,11.016,5.685,5.558,7.681,11.065,P<0.01).Among 54 cases IBS-D patients(1 patient lost to follow-up),61.11%(33/54) significantly improved,24.07%(13/54) improved,14.81%(8/54) invalid,the total effective rate was 85.19%(46/54).Conclusion There is correlation between food intolerance and IBS-D.According to the Results of the detection of food specific IgG antibody,food rejectingtrend treatment can effectively improve the symptoms of IBS-D.
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Objective To analyse distribution of age and gender characteristics of specific IgG(sIgG)antibodies and specific IgE (sIgE)antibodies of 13 types of food allergens in patients with food anaphylaxis,and to explore the relationship between sIgG and sIgE in food anaphylaxis.Methods 314 cases of patients from 2009 to 2012 were selected as subjects,and divided into underage group(1 63 cases)and adult group(1 5 1 cases).Serum sIgG of 13 types of food allergens were detected by using enzyme linked immu-nosorbent assay,serum sIgE of these food allergens were detected by using immune capture.Results 80.25% of the patients were sIgG-positive,and no obvious gender differences were found;while the positive rates of sIgG in the underage group(94.48%)were higher than that in the adult group(64.90%),there were statistically significant differences(P < 0.05 ).34.39% of the patients were sIgE-positive.The positive rates of sIgE in male patients(40.68%)were higher than that in female patients(26.28%),and that in the underage group(55.21%)were also higher than that in the adults group(1 1.92%),there were statistically significant differences(P <0.05).Conclusion The total positive rates and its distribution characteristics of sIgG and sIgE of same food aller-gens were obviously different.Food anaphylaxis might be associated with age,gender,food types and individual diversity.
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PURPOSE: Our previous study indicated that the presence of wheat-specific IgG1 and IgG4 antibodies was associated with work-related symptoms in workers exposed to wheat flour. We performed this study to investigate the genetic polymorphisms of beta2-adrenergic receptors and wheat-specific antibodies in association with the clinical parameters of baker's asthma. MATERIALS AND METHODS: In total, 379 subjects working in a single industrial bakery were enrolled in this study. The skin prick test was performed with common inhalant allergens and wheat flour extract. The presence of serum- specific IgE, IgG1, and IgG4 antibodies to wheat flour were determined by ELISA. Whole blood samples were obtained for genotype analysis. Subjects were genotyped with regard to five candidate single nucleotide polymorphisms (SNPs) of the beta2-adrenergic receptor gene (ADRB2; -47 T>C, 46 A>G, 79 C>G, 252 G>A, and 523 C>A) using a single-base extension method. RESULTS: No significant associations were observed between the genotype/allele frequencies of any of the SNPs tested and any clinical parameters. The haplotype of ADRB2 (GAA composed of 46 A>G, 252 G>A, and 523 C>A) was significantly associated with work-related symptoms (pG and haplotype [GAA] of ADRB2, the prevalence rates of wheat-specific IgG1 antibodies and lower respiratory symptoms increased significantly with exposure intensity (both p<0.05). CONCLUSION: The findings of the present study suggest that ADRB2 genetic polymorphism may contribute to the development of work-related symptoms in workers exposed to wheat flour, which can lead to baker's asthma.
Subject(s)
Adult , Female , Humans , Male , Allergens/immunology , Asthma/genetics , Enzyme-Linked Immunosorbent Assay , Flour , Haplotypes , Immunoglobulin G/immunology , Inhalation Exposure/analysis , Occupational Exposure/analysis , Polymorphism, Genetic , Polymorphism, Single Nucleotide , Receptors, Adrenergic, beta-2/genetics , Skin Tests , Triticum/immunologyABSTRACT
A study was performed to investigate the effects of exercise and <I>Spirulina platensis</I> (SPL) intake on the hapten specific immune response of growing mice.<BR>Male BALB/C mice aged five weeks were divided into 6 groups : Group A was a control group given a normal diet ; group B, sedentary with a normal diet ; group C, exercise with a normal diet ; group D, control with SPL diet ; group E, sedentary with a SPL diet ; group F, exercise with a SPL diet. The mice in groups C and F were trained by swimming for about 30 min 4 times a week for 5 weeks. The SPL diet was a mixture of SPL (20%) and the normal diet (80%) . At 4 weeks after the experiment, the mice belonging to groups B, C, E and F were sensitized with 1% toluene-2, 4-diisocyanate (TDI) . Five days after sensitization, TDI was painted on the ears of the mice, and delayed type hypersensitivity (DTH) was evaluated by measuring the ear thickness at 24 h later as an index. After this evaluation, the body weights of the mice, the weights of the thymus and spleen, and serum TDI-specific IgG antibody levels as an index of humoral immunity, were measured.<BR>In the mormal diet groups, the highest DTH reaction was shown in the exercise group, followed by the sedentary group. On the other hand, the DTH reactions in the SPL diet groups were significantly suppressed in both the sedentary and exercise groups. However, a slightly higher DTH reaction was shown in the exercise group than in the sedentary group. Body weights of mice in the exercise groups receiving both the normal and SPL diets were suppressed in comparison with the control and sedentary groups. Although increased spleen weights were shown in all the sensitized groups, thymus weights in the 6 groups were not changed. TDI-specific IgG antibody levels were also not changed in any of the TDI sensitized groups.<BR>From these results, the SPL diet seemed to effectively suppress the DTH reaction, and might be effective for treatment of various types of contact hypersensitivity which are currently the focus of clinical attention.
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A study was performed to investigate the effects of exercise and <I>Spirulina platensis</I> (SPL) intake on the hapten specific immune response of growing mice.<BR>Male BALB/C mice aged five weeks were divided into 6 groups : Group A was a control group given a normal diet ; group B, sedentary with a normal diet ; group C, exercise with a normal diet ; group D, control with SPL diet ; group E, sedentary with a SPL diet ; group F, exercise with a SPL diet. The mice in groups C and F were trained by swimming for about 30 min 4 times a week for 5 weeks. The SPL diet was a mixture of SPL (20%) and the normal diet (80%) . At 4 weeks after the experiment, the mice belonging to groups B, C, E and F were sensitized with 1% toluene-2, 4-diisocyanate (TDI) . Five days after sensitization, TDI was painted on the ears of the mice, and delayed type hypersensitivity (DTH) was evaluated by measuring the ear thickness at 24 h later as an index. After this evaluation, the body weights of the mice, the weights of the thymus and spleen, and serum TDI-specific IgG antibody levels as an index of humoral immunity, were measured.<BR>In the mormal diet groups, the highest DTH reaction was shown in the exercise group, followed by the sedentary group. On the other hand, the DTH reactions in the SPL diet groups were significantly suppressed in both the sedentary and exercise groups. However, a slightly higher DTH reaction was shown in the exercise group than in the sedentary group. Body weights of mice in the exercise groups receiving both the normal and SPL diets were suppressed in comparison with the control and sedentary groups. Although increased spleen weights were shown in all the sensitized groups, thymus weights in the 6 groups were not changed. TDI-specific IgG antibody levels were also not changed in any of the TDI sensitized groups.<BR>From these results, the SPL diet seemed to effectively suppress the DTH reaction, and might be effective for treatment of various types of contact hypersensitivity which are currently the focus of clinical attention.