Ordering of antibodies, that react with cardiac muscle fiber and interstitial connective tissue antigens, in different immunoglobulin classes

Sera of patients suffering from rheumatic diseases and myocarditis were examined on the sections of human and bovine myocardial tissue by indirect immunofluorescence with the use of pure IgG antibodies or monospecific sera against IgG, IgA and IgM. It was shown that antibodies reacting with different myofibers and interstitial connective tissue of the heart belong to the main immunoglobulin classes (IgG, IgA and IgM). There was a significant predominance of IgG antibodies as shown by the frequency of their detection and by the titer height. The predominance of antibodies to certain classes of immunoglobulins did not correlate with a specific disease entity. The frequency of detecting antibodies to a certain immunoglobulin class was in good agreement with the time of the disease onset. Moreover, the frequency of positive reactions due to IgG, IgA, and IgM antibodies correlated with the level of the appropriate immunoglobulins in the test sera.     

Diagnostic value of dengue virus-specific IgA and IgM serum antibody detection

The diagnostic value of dengue virus (DV)-specific immunoglobulin A (IgA) serum antibody detection, by an indirect immunofluorescence assay (IFA) was evaluated. For this study, the kinetics of DV-specific IgA serum antibodies was analysed in two experimentally immunised macaques, paired samples from 35 patients suspected of a primary or secondary DV infection, paired sera from patients with high levels of IgA specific antibodies against influenza virus (n = 15), sera from patients with other viral infections (n = 40) and healthy blood donors (n = 10), which served as controls. The presence of DV-specific IgA serum antibodies in humans and in monkeys was compared with that of DV-specific IgM demonstrated in a capture enzyme-linked immunosorbent assay (ELISA). The development of DV-specific IgA and IgM antibodies in macaques proved to be similar to that observed in humans with a DV infection. In sera obtained from suspected primary DV patients during the acute phase and convalescent phase, DV-specific IgA was detected in 1/6 (17%) and 6/6 (100%), whereas IgM was detected in 4/6 (67%) and 5/6 (83%), respectively. In sera from suspected secondary DV patients during the acute phase and convalescent phase, DV-specific IgA was detected in 18/29 (62%) and 28/29 (97%), whereas IgM was detected in 20/29 (69%) and 28/29 (97%), respectively. The control group consisted of five paired serum samples from yellow fever vaccinated individuals and a patient with acute tick-borne encephalitis, 15 paired serum samples from patients with high levels of IgA antibodies specific for influenza virus and 40 serum samples from patients with specific IgM antibodies against other viruses. Ten serum samples from healthy blood donors were included. Among the control serum samples, in one patient, both DV-specific IgA and IgM antibodies were present, and in three sera DV-specific IgM antibodies could be demonstrated. These data suggest that detection of DV-specific IgA serum antibodies by IFA may have additional value for the diagnosis of DV infection.     

Normal human sera contain antibodies directed at Fab of IgA

Serum samples from 26 normal volunteers were evaluated by isotype-specific ELISA for the presence of IgG and IgM antibodies directed at IgA. Although there were wide variations in antibody levels, anti-IgA antibodies of both isotypes were found in all individuals tested. The anti-IgA activity was detected against a variety of polymeric and monomeric IgA1 and IgA2 myeloma proteins containing both kappa and lambda light chains. By using Fab and Fc fragments generated by incubation of an IgA1 myeloma protein with IgA1 protease, it was shown that the anti-IgA activity was specific for the Fab portion of the IgA molecule. It was also demonstrated that the serum of two individuals contained both IgG and IgM activity directed at autologous affinity-purified IgA. IgM antibody levels against both whole IgA and Fab of IgA were significantly higher than IgG antibody levels. Cells producing anti-IgA antibodies of both isotypes were detected in lipopolysaccharide-stimulated human spleen.     

Natural and immune human antibodies reactive with antigens of virulent Neisseria gonorrhoeae: immunoglobulins G, M, And A

Natural and immune human antibodies reactive with heat-labile and heat-stable antigens of virulent Neisseria gonorrhoeae were studied by use of an indirect fluorescent-antibody (IFA) procedure. The immunoglobulin class of the reactive antibodies was identified by using fluorescein-conjugated antisera specific for human IgG, IgA, or IgM in the IFA procedure. The effects of heat and mercaptoethanol on IFA reactivities were also studied. It appeared that antibodies of the IgG, IgM, and IgA classes present in the sera of both infected persons (immune antibodies) and normal persons with no history of gonococcal infection (natural antibodies) react with heat-stable somatic antigens. Immune IgG antibodies, however, were distinguishable from natural IgG antibodies by their ability to recognize heat-labile surface antigens. The distinction between natural and immune IgM antibodies was less obvious. IgM antibodies from both infected and normal persons appeared to react with heat-labile antigens. Some, but not all, infected persons had immune IgA antibodies to heat-labile as well as to heat-stable antigens. Treatment of sera with mercaptoethanol had no effect on IgG antibodies. The IFA activity of IgM antibodies was decreased, but not abolished. The effects of mercaptoethanol on IgA antibodies were variable. Some sera showed a decrease in IgA titer, and others showed an increase in IgA activity to certain antigens. Immune IgG antibodies were more resistant to heating than were natural IgG antibodies. Natural and immune IgM antibodies appeared equally sensitive to heating. IgA activity, on the other hand, was increased by heating sera at 60 C, but was decreased at higher temperatures. Thus, it appears that natural and immune human IgG antibodies to N. gonorrhoeae may be distinguished by their interactions with heat-labile antigens and by their resistance to heating.     

Composition of immunoglobulins in brucellosis patients using DEAE-cellulose column chromatography.

The composition of immunoglobulins in patients with brucellosis was studied. The method of ion-exchange chromatography on DEAE-cellulose columns was used to define more precisely the physico-chemical character of cysteine-resistant antibodies. The study of IgM, IgA and IgG fractions obtained from the patients sera showed the IgG fraction to possess the greatest serological activity in the agglutination reaction, in the passive haemagglutination reaction and in Coomb's test. Specific antibodies in the remaining 2 fractions (IgA and IgM) were found only in single patients in low titres, mainly in Coomb's test (incomplete antibodies). The study of IgM, IgA and IgG serum fractions before and after cysteine treatment revealed cysteine-resistant antibodies to be usually IgG globulins. The presence of specific IgG antibodies in the sera of patients was found to correlate with active clinical manifestations of brucellosis.     

Specific antibodies and their role in the formation of antidiphtheria immunity

In human sera, studied with the use of the enzyme immunoassay, antidiphtheria postvaccinal antitoxic IgG and naturally acquired antibacterial IgG, IgM and IgA were detected. In the blood of children and adults aged up to 50 years antitoxic IgG were present at normal and high concentrations. In 50% of children antibacterial IgA were absent, while specific antibacterial IgM could be found at high concentrations. Changes in the content of antibacterial antibodies of different classes in sera were observed with age. More than 90% of adults had antibacterial IgA and IgG at normal and hig concentrations, while the level of IgM decreased. Under the influence of ecological, social, anthropogenic and other environmental factors the optimum levels of specific antibodies were replaced by anomalous ones, which led to an increased number of persons susceptible to diphtheria infection and in the intensity of the circulation of the infective agent. The deficiency of antidiphtheria antibacterial antibodies in the blood determined the necessity of correcting immunity by means of not only toxoid, but also bacterial antigens.     

The determination in saliva of IgA antibodies to Shigella ribosomes for the diagnosis of dysentery

The levels of antiribosomal antibodies to Shigella ribosomes in serum and saliva samples from 38 dysentery patients (15 S. sonnei cases and 23 S. flexneri cases), 14 patients with salmonellosis and 136 healthy adults were determined in ELISA with ribosomes from S. sonnei R-mutant used as solid-phase antigen. High levels of "normal" antiribosomal IgA, IgG and IgM antibodies were revealed in the sera of healthy persons while the level of salivary IgA antibodies was very low. In dysentery infection no increase in the levels of serum IgG and IgM antibodies and only a slight increase in the level of IgA antibodies were revealed. Local immune response was manifested by the early (on days 2-4 from the onset of infection) and significant augmentation (12- to 16-fold) of salivary antiribosomal IgA antibodies. An increase in the level of these antibodies was registered in 95-100% of dysentery patients but not in patients with salmonellosis, which made it possible to recommend the method for diagnosing shigellosis. Immune response to Shigella ribosomal antigens, in contrast to the response induced by Shigella O-antigen, is almost exclusively local.     

The rabbit antibody response to immunization with Haemophilus ducreyi A comparative study for immunoglobulin detection using diffusion-in-gel enzyme-linked immunosorbent assay, countercurrent immunoelectrophoresis, and double-diffusion-in-gel

Abstract Haemophilus ducreyi was used for immunization of rabbits. The serum level of specific IgG, IgM, and IgA antibodies to the same agent was determined by diffusion-in-gel enzyme-linked immunosorbent assay (DIG-ELISA) and precipitating antibodies were detected with countercurrent immunoelectrophoresis (CIE) and double-diffusion-in-gel (DD) techniques. Antibodies to H. ducreyi could be detected in all rabbits within two weeks with all three techniques used.     

Amplification of the secretory IgA response to Toxoplasma gondii using cholera toxin

Our study demonstrates that cholera toxin (CT) markedly enhances the intestinal anti-T. gondii antibody response following oral immunisation of mice with a T. gondii sonicate (TSo) and CT. The antibodies induced were mostly IgA and secretory IgA but a small quantity of IgG was also produced. In contrast, no intestinal anti-T. gondii IgM antibodies were detected. Anti-CT IgA antibodies were also present in intestinal secretions but in much lower quantities than the T. gondii-specific IgA. No anti-CT IgG nor IgM antibodies were detected. Western blot analysis showed that CT induced not only an increase of the intensity of the intestinal IgA antibody response to the 30-kDa band but also induced intestinal IgA antibodies against other major T. gondii proteins (p22, and the 28-kDa antigen) as recognised by specific monoclonal antibodies. The amplification of the anti-T. gondii secretory IgA response by means of an appropriate adjuvant may be one major step leading towards an orally induced immune protection against toxoplasmosis.     

Serodiagnostics of chlamydial infections--significance of positivity in IgA and/or IgM antibody classes only

There was followed the development of serological findings in patients with proved positivity only in classes IgA and/or IgM of chlamydial antibodies (without IgG), which can be suspected of showing "false" positivity. 184 patients were repeatedly examined for chlamydial antibodies in their sera (interval between collections up to three months) using a genus specific rELISA. Sera were also tested for the evidence of IgM antibodies against capside antigen of Epstein-Barr virus (EBV) and against cytomegalovirus (CMV) using ELISA methods. In 75 (40.8%) of patients, IgA/IgM individual positivities were demonstrated even during the following sample test(s). In 28 (15.2%) of them, IgG evidence preceded and in 29 (15.7%) other patients positive seroconversion followed in this class. In 13 (7.1%) patients, IgG antibodies disappeared and subsequently reappeared. Only in 39 (21.2%) of these probands, antibodies IgA/IgM were not demonstrated at another examination. Active EBV, resp. CMV infection was proved in 24 (13.0%), resp. in 18 (9.8%) of patients. It is concluded that the evidence of positivities only in classes IgA and/or IgM mostly signal the onset of a primary infection (reinfection) or an active infection in patients with IgG production failures respectively. In these cases, a "false" positivity can be supposed to occur only in a minor extent.     

Humoral response to selected antigens of Yersinia enterocolitica and Yersinia pseudotuberculosis in the course of yersiniosis in humans. I. Occurrence of antibodies to enterobacterial common antigen (ECA)

The antibodies against the Enterobacterial Common Antigen (ECA) were detected using the ELISA in 293 serum samples collected from 185 persons suspected for yersiniosis, as well as 115 serum samples from healthy individuals (blood donors). The presence of IgA antibody in diagnostically significant titres for ECA were detected by ELISA in 3.5%, IgG in 13.0%, and IgM in 5.2% of blood donors. Statistical analysis showed that the frequency of detecting antibodies for ECA among the patients with yersiniosis was significantly higher (p < 0.05) in relation to the blood donors. Most frequently the elevated antibody levels were detected among patients with reactive arthritis (IgA 29.2%, IgG 35.4%, IgM 16.7%) while the most infrequent among patients with abdominal pain in acute phase of yersiniosis (IgA 14.9%, IgG 25.3%, IgM 19.5%). The level of antibodies for ECA, together with age increased reaching its peak, on the average, among individuals aged 41 - 60 years. In majority of the individuals studied antibodies of the IgG class reached the level much higher in relation to those of the IgA and IgM classes. The obtained results showed that the detection of antibodies to ECA may be useful in serodiagnosis of Yersinia infections.     

Generation of monoclonal antibodies to Macaca mulatta (rhesus) IgA

One IgG1 and five IgM murine monoclonal antibodies (mAb) specific for rhesus (Rh) IgA were generated. These mAbs bound to Rh IgA but not IgG or IgM when tested by enzyme-linked immunosorbent assay. Immunoblotting revealed that the mAbs reacted with the alpha heavy chain of Rh but not human IgA. The IgG1 anti-Rh IgA mAb detected IgA-producing cells in sections of monkey gut examined by immunofluorescent staining. These mAbs should be useful for characterizing IgA responses in the Rh monkey.     

Immunoglobulins and antibodies of various classes in children immunized with live oral Shigella sonnei vaccine from the spontaneous mutant]

The authors determined the immunoglobulin and specific antibodies level in the blood serum of 17 children aged from 7 to 10 years during the immunization with live dysentery Some vaccine. Mancini's test demonstrated the absence of any differences in the amount of IgA and IgG in children of the given age group and in adults before the immunization; in comparison with adults, IgM was increased in children. 14 to 20 days after the immunization in children there was a significant elevation of the IgG only, whereas in adults the immunoglobulin level of all the 3 classes increased significantly. The titres of specific antibodies of the IgA-, IgG-classes and of hemagglutinins before the immunization detected by Coombs' test failed to differ in children from the titres of antibodies of these classes in adults; the level of IgM antibodies was much greater in children than in adults. The changes and accumulation of antibodies of various classes in children and adults during the enteral immunization with live dysentery vaccine differed significantly: in children the vaccine stimulated the IgA- and the IgM-antibody synthesis, whereas adults responded to the immunization by increased production of all the 3 antibody classes. On the basis of the noted immunological shifts a conclusions was drawn on a marked local immunization activity of the live enteral Sonne dysentery vaccine from the spontaneous mutant in children.     

ELISA间接法检测呼吸道合胞病毒和副流感病毒血清IgM和IgA抗体

建立了检测呼吸道合胞病毒(RSV)和副流感病毒(PFV)血清特异性IgM和IgA抗体的间接ELISA方法。在方法统一的基础上比较了检测IgG、IgM和IgA抗体的结果,证明检测血清IgM和IgA可以作为RSV和PFV感染的早期诊断指标。检测了120份临床急性下呼吸道感染患儿的血清,RSV-IgM检出率为33.3％,RSV-IgA为36.7％;PFV-IgM为27.5％,PFV-IgA为31.6％。提出了对RSV和PFV感染以检测特异性IgA替代IgM或两者互补的设想。     

Anaphylactic properties of mouse monoclonal IgG2a antibodies

Mouse monoclonal antibodies (10 hybridoma antibodies specific for soluble antigens, 8 hybridoma antibodies specific for H-2 $\text{K}\text{D}$ antigens, and 9 myeloma immunoglobulins, among which 5 had a known specificity) of the IgG1, IgG2a, IgG2b, IgG3, IgA, and IgM isotypes were studied for their ability to induce mouse mast cell degranulation in vitro, in the presence of specific antigen or after heat aggregation. Monoclonal IgG1 antibodies, as well as IgG2b, IgG3, IgA, and IgM behaved as polyclonal antibodies of corresponding classes: all IgG1 induced mast cell degranulation with typical characteristics of IgG-mediated anaphylactic reactions, whereas IgG2b, IgG3, IgA, and IgM did not. By contrast, 2 hybridoma IgG2a and 3 myeloma IgG2a induced intense mast cell degranulation that could not be explained by a contamination with IgG1 or IgG1-IgG2a hybrid molecules. IgG2a-mediated reactions were observed in four different situations: soluble antigen-hybridoma IgG2a complexes, specific H-2 antigen-bearing mast cells challenged with hybridoma IgG2a anti-H-2, heat-aggregated myeloma IgG2a, and soluble antigen-myeloma IgG2a complexes. The conclusion was reached that mouse mast cells could be activated by mouse monoclonal IgG2a antibodies through a noncytotoxic, complement-independent mechanism involving mast cell Fcγ receptors.     

The production of specific immunoenzyme conjugates to human immunoglobulins by the glutaraldehyde method]

The results of studies aimed at obtaining class-specific conjugates to human immunoglobulins to be used in the enzyme immunoassay (EIA) are presented. At the first stage of the studies purified IgA, IgM and IgG preparations were obtained. These preparations were used for obtaining immunologically active immunosorbents on the basis of bromocyanic Sepharose. Specific antibodies to human IgA, IgM and IgG were isolated from animal sera by the method of affinity chromatography. These antibodies were conjugated with peroxidase by the glutaraldehyde method. The specific activity of the conjugates were determined in EIA. The results thus obtained revealed that all preparations exhibited high specific activity and gave no cross reactions with immunoglobulins of other classes.     

Characteristics of IgA Anti-HIV Antibodies in Plasma from Patients with HIV Infection

The concentration of total IgA and the specificity and molecular size of IgA anti-human immunodeficiency virus (HIV) type-1 antibodies in plasma obtained from individuals at different stages of HIV infection were analyzed. The concentration of total IgA in the plasma was not decreased even in the late stage of HIV infection, in contrast with those of total IgG and IgM. The IgA anti-HIV antibodies differed to the IgG anti-HIV antibodies in their specificity as determined by Western blotting. The IgA antibodies mainly bind to Env glycoproteins. The IgA anti-HIV antibodies in plasma were detected between IgG and IgM by gel filtration, suggesting the presence of polymeric IgA anti-HIV antibodies. These results indicate that the production of non-specific IgA in plasma is enhanced by unknown mechanisms in every stages of HIV infection, and suggest that IgA anti-HIV antibodies in plasma which are possibly polymeric and have unique specificity may play an important role in HIV infection.     

Frequency of specific anti-Toxoplasma gondii IgM, IgA and IgE in colombian patients with acute and chronic ocular toxoplasmosis

We studied the frequency of specific anti-Toxoplasma IgM, IgA and IgE antibodies in serum of 28 immunocompetent Colombian patients, selected by ophthalmologists and with lesions that were compatible with ocular toxoplasmosis. Patients were classified in three groups: (i) group 1 consisted of ten patients with a first episode; (ii) group 2, with seven patients with a recurrence and (iii) group 3, consisted of eleven patients with chronic chorioretinal lesion without uveitis. We found that 10/28 (35%) of Colombian patients with ocular toxoplasmosis possessed at least one serological marker for Toxoplasma infection different from IgG. In group 1 (first episode), we found simultaneous presence of specific IgM plus IgA plus IgE in 1/10 (10%). In group 2 (recurrences) in 1/7 (14%) we found IgM and IgA test positives and in 1/7 (14%) we found IgM and IgE tests positives. In group 3 (toxoplasmic chorioretinal scar) the IgA serological test was positive in 2/11 (18%). These results show that serum IgM or IgA or IgE can be present during recurrences.     

Natural antibodies and immune antibodies of human ABO blood group system

Sera of normal and isoimmunized persons genotype OO and A₁O were fractionated to separate the three main immunoglobulin components IgG, IgM and IgA from each other. The anti-B activity was measured in every fraction and individual serum. The results indicate that the natural anti-B antibodies are of IgM molecular type, contrasting with the immune anti-B antibodies which are IgM, IgG and eventually IgA. The restriction to the IgM class and other data previously reported are discussed in relation to the origin of the natural antibodies of the human ABO blood group system.     

Serological studies of a case of fatal craniofacial mucormycosis

Counter-immunoelectrophoresis and indirect immunofluorescence tests were used in a fatal case of craniofacial mucormycosis. The indirect immunofluorescent test was rapid and more sensitive than counter-immunoelectrophoresis and provided estimation of serum antifungal antibodies (IgA, IgG and IgM). The high serum IgA titer (comparable to IgM) found in this case of acute infection suggests a role of IgA antibodies which needs further investigation.