OBJECTIVETo study the regulation of Fc receptor expression by immune complexes (ICs) on neutrophils and U937 cells.

METHODSIgA ICs, IgG1 ICs, IgG2 ICs, IgG3 ICs, IgG4 ICs, and IgM ICs were incubated with neutrophils or U937 cells for 1 h. Then their surface Fc receptors were stained by anti-Fc gammaR I, anti-Fc gammaR II , anti-Fc gammaR III, and anti-Fc alphaR I monoclonal antibodies and analyzed by fluorescent activated cell sorting (FACS).

RESULTSIgG1 ICs and IgG3 ICs up-regulated Fc gammaR II and Fc gammaR III on U937 cells, Fc gammaR I and Fc alphaR I on neutrophils. Almost all ICs down-regulated Fc gammaR II on neutrophils.

CONCLUSIONSICs can regulate Fc receptor expression on neutrophils and U937 cells, among which IgG1 ICs and IgG3 ICs are most effective.

Antibodies, Anti-Idiotypic ; immunology ; Antibodies, Monoclonal ; pharmacology ; Antigen-Antibody Complex ; immunology ; metabolism ; Antigens, CD ; immunology ; Humans ; Immunoglobulin A ; classification ; immunology ; Immunoglobulin G ; chemistry ; classification ; immunology ; metabolism ; Neutrophils ; metabolism ; Receptors, Fc ; biosynthesis ; genetics ; Receptors, IgG ; immunology ; U937 Cells ; immunology

OBJECTIVETo explore the relationship between the major allergens of 6 common allergic foods and IgA nephropathy.

METHODSA sensitive sandwich enzyme-linked immunosorbent assay (ELISA) was used to detect the serum levels of food-specific IgA1, IgG and IgE in 31 patients with IgA nephropathy and 80 healthy volunteers. All the patients were examined for a history of food allergy using a questionnaire.

RESULTSSerum levels of IgA1 and IgG against the major allergens of the 6 common allergic foods were significantly higher in patients with IgA nephropathy than in healthy volunteers (P<0.05). There was no detectable food-specific IgE antibodies in the two groups. No patients had a clear history of food allergy. All the patients with increased IgG levels specific to 4 or more foods simultaneously had proteinuria.

CONCLUSIONSSome foods especially the highly allergic ones may participate in the pathogenesis and progression of IgA nephropathy.

Adult ; Antibody Specificity ; Case-Control Studies ; Female ; Food Hypersensitivity ; classification ; immunology ; Glomerulonephritis, IGA ; blood ; immunology ; Humans ; Immunoglobulin A ; blood ; Immunoglobulin E ; blood ; Immunoglobulin G ; blood ; Male ; Young Adult

We evaluated tetanus specific IgG, IgM, IgG subclasses after DPT vaccination in infants and children. Tetanus toxoid specific IgG, IgM IgG subclasses were measured to characterize the isotope profile of antibody against tetanus toxoid. The values of the tetanus specific IgG in the positive group were significantly increased compared to those of the control group, and were significantly increased after two inoculation. Tetanus specific IgG was very low in adults and neonates. In our tetanus specific IgG subclasses study, forty-five of 56 cases (80%) showed predominantly IgG1 antibody responses to tetanus toxoid, while twenty-five of 56 cases (45%) showed IgG4 responses. Both IgG1 and IgG4 responses were demonstrated in 17 cases (30%). So we suggest that IgG was mainly involved in humoral immune response after DPT vaccination, and IgG1 may play an important role among IgG subclasses. IgG4, alone or together with IgG1, can also play a role in immune response to tetanus toxoid.
Antibodies, Bacterial/*biosynthesis ; Antibody Specificity ; Child ; Clostridium tetani/immunology ; Diphtheria-Tetanus-Pertussis Vaccine/*immunology ; Human ; Immunoglobulin G/biosynthesis/classification ; Immunoglobulin M/biosynthesis ; Infant

OBJECTIVE: To explore the role of IL-21 in the pathogenesis of myasthenia gravis (MG) and its influence on the the class switch of anti-AChR antibodies. METHODS: Blood was taken from 26 patients and 18 healthy controls, and the expression of IL-21R mRNA in peripheral blood mononuclear cells (PBMCs) was detected by RT-PCR. The expression of IL-21R on B lymphocytes was measured by flow cytometry, while the concentrations of serum IL-21 and the levels of anti-AChR-IgG and its isotype IgG(1), IgG(2), and IgG(3) were tested by ELISA. RESULTS: The serum concentration of IL-21 in the MG group was higher than that in the control group (31.686±8.499 pg/mL, 15.147±6.366 pg/mL) and the difference was significant (P<0.01). IL-21R mRNA expressed on PBMCs in the MG group was higher than that in the control group (0.139±0.052, 0.101±0.022), and the difference was significant (P<0.05). There was no difference between ocular MG and generalized MG subgroup (P>0.05). Compared with the control group, the expression of IL-21R on B lymphocytes also increased in the MG group (P<0.05). In the anti-AChR-Ab positive MG group, the serum concentration of IL-21 showed positive correlation with anti-AChR-IgG(P<0.05),but no correlation with its isotype IgG(1), IgG(2), and IgG(3), respectively(P>0.05). Expression of IL-21R mRNA in the PBMCs showed no correlation with the level of serum anti-AChR-IgG and its isotype IgG(1), IgG(2), and IgG(3), respectively(P>0.05); however the expression of IL-21R in B lymphocytes showed positive correlation with anti-AChR-IgG and it's isotype IgG(1) and IgG(3) (P<0.05,P<0.01,P<0.05), but no correlation with IgG(2) (P>0.05). CONCLUSION IL-21 might induce the class switch of anti-AChR antibodies to IgG(1) and IgG(3) isotype through IL-21R on B lymphocytes which promotes the pathogenesis of the MG.
Adolescent ; Adult ; Autoantibodies ; classification ; immunology ; Female ; Humans ; Immunoglobulin Class Switching ; immunology ; Immunoglobulin G ; classification ; Interleukins ; blood ; genetics ; Male ; Middle Aged ; Myasthenia Gravis ; blood ; immunology ; RNA, Messenger ; blood ; genetics ; Receptors, Cholinergic ; immunology ; Receptors, Interleukin-21 ; blood ; genetics ; Young Adult

PURPOSE: A possible involvement of autoimmune mechanism in the pathogenesis of bronchial asthma has been proposed. Recently, alpha-enolase protein was identified as a major autoantigen recognized by circulating IgG autoantibodies in patients with severe asthma. To evaluate a possible pathogenetic significance of these autoantibodies in severe asthma, isotype (IgG, IgA, IgM, and IgE) and IgG subclass (IgG1, IgG2, IgG3, and IgG4) distributions of autoantibodies to recombinant human alpha-enolase protein were analyzed. PATIENTS AND METHODS: We examined serum samples from 10 patients with severe asthma and 7 patients with mild-to-moderate asthma, and 5 healthy controls by immunoblot analysis. Severe asthma was defined as patients having at least 1 severe asthmatic exacerbation requiring an emergency department visit or admission in the last year despite continuous typical therapies. RESULTS: IgG1 was the predominant IgG subclass antibody response to alpha-enolase protein in patients with severe asthma. IgG1 autoantibody to alpha-enolase protein was detected in 7 of 10 patients with severe asthma (70%), 1 of 7 patients with mild-to-moderate asthma (14.3%), and none of 5 healthy controls (0%) (chi-square test; p < 0.05). IgA, IgM, and IgE autoantibodies to alpha-enolase protein could not be detected in patients with severe asthma. CONCLUSION: IgG1 subclass was the predominant type of autoantibody response to alpha-enolase protein in patients with severe asthma, suggests a possibility of IgG1 autoantibody- mediated complement activation in the pathogenesis of severe asthma.
Adult ; Aged ; Asthma/*enzymology/*immunology ; Autoantibodies/*blood/classification ; Autoantigens ; Case-Control Studies ; Complement Activation ; Female ; Humans ; Immunoglobulin G/blood/classification ; Immunoglobulin Isotypes/blood ; Male ; Middle Aged ; Phosphopyruvate Hydratase/*immunology ; Recombinant Proteins/immunology ; Young Adult

OBJECTIVESTo explore the category, quantity and clinical significance of autoantibodies on bone marrow hematopoietic cells in patients with immunorelated cytopenia and evaluate the sensitivity of direct antiglobulin reaction (Coombs test ) of bone marrow mononuclear cells (BMMNC).

METHODSThe category and the positive rate of autoantibodies on bone marrow hematopoietic stem cells, nucleated erythrocytes, granulocytes in 32 patients with uncertain immunorelated cytopenia were investigated by using BMMNC-Coombs test and double immunofluorescence flow cytometry.

RESULTSThe positive rate of autoantibodies on bone marrow hematopoietic cells tested by flow cytometry was 90.63% which was higher than that by BMMNC-Coombs test (50.0%) (p < 0.05). In 29 positive cases, IgG autoantibody accounted for 6.90%, IgM13.8%, IgG+IgA 3.4%, IgG+IgM 31.0%, and IgG+IgM+IgA 44.8%. Of the 29 Patients, 25 (86.2%) with IgG autoantibody, 26 (89.7%) with IgM and 14 (48.3%) with IgA. The patients with IgG autoantibody alone had the lowest hemoglobin levels, and those with IgM autoantibody might have intravascular hemolytic findings. The response time of patients with IgG and IgG+IgM was shorter than that of the other patients. 91.3% of the patients had autoantibodies on bone marrow hematopoietic stem cells and showed pancytopenia, and 50% of the patients had autoantibodies on nucleated erythrocytes and granulocytes. Eleven of 13 patients with negative BMMNC-Coombs tests had autoantibodies on bone marrow hematopoietic stem cells detected by FACS. There was no significant difference of the quantities of the three categories of autoantibodies of nucleated erythrocytes and stem cells. The quantities of IgA on granulocytes were lower than that of IgG and IgM. There was no significant difference between IgG and IgM on granulocytes. The quantity of IgA on hematopoietic stem cells was significantly higher than that on nucleated erythrocytes or granulocytes.

CONCLUSIONSThe sensitivity of double immunofluorescence flow cytometry assay was higher than that of BMMNC-Coombs test for detecting autoantibodies. In immunorelated cytopenia patients, the predominant autoantibody was IgM which could cause intravascular hemolysis, and the second one was IgG which could cause severe anemia. Most immunorelated cytopenia patients had autoantibodies on hematopoietic stem cells and showed pancytopenia. IgA was more easily seen on the hematopoietic stem cells.

Adolescent ; Adult ; Aged ; Autoantibodies ; classification ; metabolism ; Autoimmune Diseases ; immunology ; Bone Marrow Cells ; immunology ; Child ; Coombs Test ; Female ; Flow Cytometry ; Humans ; Immunoglobulin A ; metabolism ; Immunoglobulin G ; metabolism ; Immunoglobulin M ; metabolism ; Male ; Middle Aged ; Pancytopenia ; immunology

Hypersensitivity to the stings of the Hymenoptera has been described since antiquity. The hypersensitive reactions to insect stings vary from minor skin reactions to severe and sometimes fatal anaphylaxis. Concerns about sting hypersensitivity have been increasing because of many incidents of allergic reactions of patients to the fire ant in the southern area of the United States as well as the harvester ant in some areas. We experienced one unique case with severe allergic reactions by ant of the Ectomomyrmex spp. of the subfamily Ponerinae, which is not a harvester ant. For three years the patient had been suffering from generalized allergic reactions such as anaphylaxis after the ant stings four-five attacks in a year. We determined that her reactions were due to specific IgE mediated type I hypersensitivity by the detection of a high level of specific IgE to the ant venom in her serum. The high level of specific IgG4 to the ant venom was also noted in her serum, however, the role of ant venom IgG4 was not clearly determined.
Adult ; Anaphylaxis/*etiology ; Ant Venoms/*immunology ; Case Report ; Enzyme-Linked Immunosorbent Assay ; Female ; Human ; Immunoglobulin E/*analysis ; Immunoglobulin G/*classification ; Support, Non-U.S. Gov't

Mast cells, which are major effector cells in allergic reactions, are found in the perivascular spaces of most tissues and contain pro-inflammatory and vasoactive mediators. These mediators are released after IgE receptor cross-linking induced by allergens or other stimuli, including anaphylatoxins (C3a and C5a), aggregated IgG, certain drugs, venoms, and physical stimuli (pressure and temperature changes), as well as cytokines and neuropeptides. The excess release of these mediators can cause variable allergic symptoms and signs, such as bronchospasm, itching, flushing, nausea, vomiting, diarrhea, abdominal pain, vascular instability, and anaphylaxis. Furthermore, mast cell disorders may involve either excessive proliferation of mast cells or abnormal mast cell reactivity. Mast cell disorders can be broadly divided into 3 types: primary, secondary, and idiopathic. All of these disorders present with signs and symptoms of mast cell activation and differ in severity and involvement of various organ systems. The best characterized primary disorder is mastocytosis. Systemic and cutaneous forms of the disease are well described. Secondary disorders include typical allergic diseases and some types of urticarial diseases. In this article, the biochemical characteristics of mast cells and the role of mast cells in allergic inflammation, as well as the classification, diagnosis, and management of mast cell-related disorders, will be reviewed.
Abdominal Pain ; Allergens ; Allergy and Immunology ; Anaphylatoxins ; Anaphylaxis ; Bronchial Spasm ; Classification ; Cytokines ; Diagnosis ; Diarrhea ; Flushing ; Hypersensitivity ; Immunoglobulin E ; Immunoglobulin G ; Inflammation* ; Mast Cells* ; Mastocytosis ; Nausea ; Neuropeptides ; Pruritus ; Venoms ; Vomiting

This study was performed to characterize the humoral immune responses with isotype profiles in Mycobacterium tuberculosis infection. PPD-Specific IgG and IgG subclasses were measured using ELISA in 212 patients with pulmonary tuberculosis. The values of PPD-specific IgG were significantly higher in pulmonary tuberculosis patients than those in the control group, and were correlated to the severity of illness (P < 0.01). The specificity and sensitivity of ELISA for IgG antibodies were 1.0 and 0.81, respectively as determined in 212 sera from tuberculosis patients and 44 from healthy controls. The positive predictive value was 1.0 (171/171), while negative predictive value was 0.52 (44/85). The values of PPD-specific IgG were significantly decreased after 2-4 months of treatment. Among the moderately and far advanced pulmonary tuberculosis patients, the values of PPD-specific IgG were significantly decreased in responders after 6 months of treatment. However, PPD-specific IgG in nonresponders was increased (P < 0.01). PPD-specific IgG subclass responses were evident to all four IgG subclasses. No changes of isotype response according to the severity of the disease were observed.
Adolescent ; Adult ; Aged ; Child ; Child, Preschool ; Enzyme-Linked Immunosorbent Assay ; Female ; Humans ; Immunoglobulin G/*blood/classification ; Infant ; Infant, Newborn ; Male ; Middle Aged ; Tuberculin/*immunology ; Tuberculosis, Pulmonary/*immunology

To establish a sensitive, rapid and simple gold immunochromatography assay (GICA) for detecting Asia1 type of foot-and-mouth disease virus (FMDV) from the field samples. The purified anti-FMDV type Asia1 monoclonal antibody labeled with colloidal gold and the goat anti-Guinea pig IgG were wrapped onto nitrocellulose membrane as the test line (T line) and the control line (C line), respectively. The strip was then further optimized. A total of 87 field samples were detected. The results indicated a correct rate of 98.8% for detecting FMDV Asia1 type. No cross reaction was found with swine vesicular disease (SVD) and FMDV O, A and C type antigen. The sensitivity of the strip can reach to 10(-4) (TCID50 6.25). It had the same results for positive and negative specimens tested in three times. This strip could be stored at 4 degrees C for three months. In this study, the established gold immunochromatographic strip test kit is simple, rapid, sensitive and specific for detecting FMDV type Asial, and is potentially useful for the for pen-side diagnosis.
Animals ; Antibodies, Monoclonal ; Chromatography ; methods ; Foot-and-Mouth Disease ; diagnosis ; Foot-and-Mouth Disease Virus ; classification ; immunology ; isolation & purification ; Gold Colloid ; Immunoassay ; methods ; Immunoglobulin G ; immunology ; Reagent Strips ; Sensitivity and Specificity