IgG Immunoglobulin Classes Research Articles

IgA immunoglobulin isotype of rheumatoid factor in primary Sj\xf6gren\u2019s syndrome

Primary Sjögren’s syndrome (pSS) is an autoimmune disease with autoantibodies overproduction, including rheumatoid factors (RF). RF-IgA, IgG immunoglobulin classes are suggested as potential biomarkers of pSS. We studied 76 patients with pSS (ACR/Eular 2017); laboratory tests included ESR, C-reactive protein, concentrations of gamma globulins, RF, Anti-SS-A/Ro, and anti-SS-B/La. Eye dryness and keratoconjunctivitis sicca were confirmed with Schirmer’s test, the ocular staining score (OSS) using lissamine green, fluorescein staining and biopsy of minor salivary gland with the histopathological evaluation. Differences between groups were analyzed with U Mann–Whitney test. Correlations between quantitative variables were assessed with the Spearman correlation coefficient.. The best diagnostic values of immunoglobulin concentration for discriminating pSS patients and healthy individuals are for RF-IgA. With cut-off of 21.5 EU/mL, the sensitivity is 72% and specificity is 100%. Very high specificity (100%) is also obtained for RF-IgM concentration of 74.1 EU/mL. Sensitivity is, however, smaller than that for RF-IgA and amounted to 61%. The RF-IgG is the poorest indicator of pSS with 51% of sensitivity and 95% of specificity. To summarize RF-IgA strongly associate with anti-SS-A and anti-SS-B autoantibodies. Both RF-IgA and RF-IgM may be used as diagnostic tools for pSS. Conclusions: among the three studied rheumatoid factor subtypes, RF-IgA showed the best diagnostic accuracy for pSS. RF-IgA correlated with anti-SS-A/Ro and anti-SS-B antibodies even more closely than RF-IgM. The assessment of the RF-IgA serum concentration may be helpful in the process of establishing pSS diagnosis.

Frequency and specificity of alloantibodies to HNA system antigens in donors of blood and blood components

Aim. To study the rate of human neutrophil antigens (HNA) alloimmunization in donors of blood and blood components.
 Methods. The study included blood samples of 1,127 donors who donated blood and its components in the Russian Scientific and Research Institute of Hematology and Transfusiology, Saint Petersburg, 635 male and 492 female. 36.18% of female donors were aged between 18 and 30 (n=178) and 63.82% were aged between 30 and 60 (n=314). The medical histories of all donors did not contain the records about the transfusion of blood components. Screening and identification of HNA alloantibodies were performed using the flow cytometric granulocyte immunofluorescence test with monoclonal antibodies CD16-PE, CD45-PC7, CD19-APC, Goat F(ab')2 Anti-Human IgG-FITC and the panel of donor neutrophils with detected HNA genotypes.
 Results. The frequency of HNA alloantibodies in blood donors was 0.35% (n=4). No HNA alloantibodies were found in the male donors. Alloantibodies were detected only in female blood donors aged between 30 and 60. HNA antibody frequency in female donors was 0.81%. It were detected anti-HNA-1a, anti-HNA-3b and anti-HNA-4b antibodies of the IgG immunoglobulin class. In one donor, the specificity of antibodies could not be established. To establish whether detected antibodies in immunized donors were alloantibodies, HNA genotypes were determined.
 Сonclusion. HNA alloantibodies occur with low frequency and are determined in 0.35% of blood donors. Alloantibodies were detected only in female donors and were directed against HNA-1a, HNA-3b and HNA-4b. The frequency of HNA antibodies in female donors was 0.81%. HNA genotyping confirmed that detected antibodies were alloantibodies.

Development of Anti-e after Platelet Concentrate Transfusion

Platelet concentrates (PC) is prepared from donated whole blood units by centrifugation and subsequent pooling of 4-6 units Advancing Transfusion and Cellular Therapies Worldwide Advancing Transfusion and Cellular Therapies Worldwide. Thus, PC may contain a small amount of donor RBC. We report a case of a 60 year-old male patient with past medical history of coronary artery disease, who presented to our emergency department with shortness of breath. Previous medical history indicated a recent admission, one month prior, to another local hospital for shock and respiratory failure. Type and screen (T/S) done at that time reveal an O+ blood type with negative antibody screen. During that admission, the patient received only 5 doses of PC (2-group O+, 2-group O-, and 1-group A-). He denied any other recent blood product transfusions at any other facility. Our current T/S, and before any transfusions, showed a positive antibody screen. A panel for antibody identification was performed. The antibody reacted with 9 out of 10 reagent cells. The reactivity was predominately at room temperature and 37°C phases indicating an IgM class antibody. Some reactivity was also seen at AHG (anti-human globulin) phase indicating an IgG class antibody. The auto control was negative. Testing additional cells revealed an anti-e specificity. Patient’s “e” antigen typing was performed and found to be negative indicating that this is a true allo-antibody. Since anti-e antibody predominantly exists as an IgG immunoglobulin class antibody, the presence of IgM class reactivity suggests that this may be a newly developed antibody. This case illustrates that antibodies to RBC antigens can develop after platelet transfusion.

Etiology of sperm immunity in women

Sperm immunity in females can reduce the likelihood of natural conception, and sperm antibodies from female sera have been shown to inhibit IVF in humans and in several animal models. The etiology of sperm immunity in human females is unknown, but several possible mechanisms have been proposed, including cross-reactivity with microbial antigens and interferon gamma-mediated potentiation of the antisperm immune response in women whose male partners have sperm autoantibodies in their semen. This article reviews these ideas and postulates a novel hypothesis based on the potential for the generation of anti-idiotype antibodies in women whose partners have sperm antibodies in their semen.

Cold antibody autoimmune hemolytic anemias

The cold antibody autoimmune hemolytic anemias (AIHAs) are primarily comprised of cold agglutinin syndrome (CAS) and paroxysmal cold hemoglobinuria (PCH) but, in addition, there are unusual instances in which patients satisfy the serologic criteria of both warm antibody AIHA and CAS ("mixed AIHA"). CAS characteristically occurs in middle-aged or elderly persons, often with signs and symptoms exacerbated by cold. The responsible antibody is of the IgM immunoglobulin class, is maximally reactive in the cold but with reactivity up to at least 30 degrees C. Therapy is often ineffective, but newer agents such as rituximab have been beneficial in some patients. PCH occurs primarily in children, often after an upper respiratory infection. The causative antibody is of the IgG immunoglobulin class and is a biphasic hemolysin that is demonstrated by incubation in the cold followed by incubation at 37 degrees C in the presence of complement. Acute attacks are frequently severe but the illness characteristically resolves spontaneously within a few days to several weeks after onset and rarely recurs. Treatment consists of supportive care, with transfusions frequently being needed.

The Immunoglobulin Class, the Subclass and the Ratio of k:λ Light Chain of Autoantibodies to human Insulin in Insulin Autoimmune Syndrome

The immunoglobulin class, subclass and the k:lambda light chain ratio of insulin autoantibodies were determined in the sera of twenty-four patients with insulin autoimmune syndrome. All sera proved to be of the IgG immunoglobulin class but exhibited various IgG1:IgG2:IgG3:IgG4 ratios. The ratio of k:lambda light chain ranged from 1:0.13 to 1:0.75 with the exceptions of two sera that were characterized as IgG1(k) and IgG1(lambda).

Simple radioimmunobinding assay for quantitation of sperm antibodies of IgG immunoglobulin class.

The immunobead test (IBT) is an excellent test for initial sperm antibody screening and evaluation but is impractical when used to quantitate antibody levels using a twofold dilution series. The aim of this study, therefore, was to develop a relatively simple radioimmunobinding assay that would allow quantitation of sperm antibodies of IgG immunoglobulin class, which predominate in male sera. [125I]-Protein G was chosen as the radioligand because it binds to all IgG subclasses, but not to IgA or IgM. The results of the investigation indicate that the [125I]-protein G assay (PGA) allows efficient quantitation of sperm antibodies, as evidenced by a highly significant (P less than .0001) correlation (Spearman's, Rs = 0.94) between the PGA results and IgG-IBT titres.

Anti asialo GM1 antibody detected in the patients' sera from systemic lupus erythematosus and Behçet's diseases with neurological manifestations.

A high incidence of antibody to asialo GM1 was observed in the sera from the patients with Systemic Lupus Erythematosus (SLE) and Behçet's disease with neurological manifestations, using Enzyme Linked Immunosorbent Assay (ELISA), and Thin-layer Chromatography (TLC) immunostaining. The sera from 60 out of 102 cases of SLE with neurological disorders and 6 out of 10 patients with neuro Behçet's disease showed antibody activity against asialo GM1 but not against the asialo GM2, GM1 and galactocerebroside. In 7 out of 123 cases SLE having a history without neurological manifestations and 1 out of 19 Behçet's patients without neurological disorders, antiasialo GM1 antibody could be detectable. However, sera from the patients with other autoimmune diseases, such as RA (60 cases) and P S S (32 cases) or from normal subjects did not show any antibody activity against asialo GM1. Antiasialo GM1 antibody activity presents in both IgM and IgG immunoglobulin classes by class specific ELISA and TLC immunostaining. These studies suggest that detection of antiasialo GM1 antibody may be useful in clinical diagnosis and these autoantibody plays a important role in the pathogenesis of neurological manifestations accompanying SLE and Neuro-Behçet's disease.

こう原病患者に対する血しょう交換療法

Plasma exchange was performed in a total 18 patients of 11 rheumatoid arthritis (RA), 3 progressive systemic sclerosis (PSS), 1 polymyositis (PM), 1 dermatomyositis (DM) and 2 mixed connective tissue disease (MCTD) . Serum levels of immunoglobulins and complement and also numbers of lymphocyte subsets and its function were measure before and after treatment. Plasma separator AP-05-H (ASAHI Medical Co.) with menbrane filters was used as substitute for the exchanged plasma of 2, 000 to 3, 000ml in each trial.The treatment seemed to be effective in 9 of 11 RA patients and two of which showed a disappearance of their subcutaneous nodules. The Skin ulcers in the legs found in 2 PSS patients decreased in their size and sclerosis of the skin found in one PSS patient relieved. Respiratory disorder found in one PM patient improved. Muscle weakness and histologic finding of myositis found in one DM patient improved. Severe myalgia and muscle weakness in one MCTD patient improved.In laboratory data, serum levels of total protein, γ-globulin, immunoglobulin class of IgG, IgA and IgM, C3 and C4 decreased significantly. Decrease of numbers of OKT-8 positive cells and increase of the ratio of OKT-4/OKT-8 positive cell were significant.

Preferential reactivity of certain human and rabbit IgM and IgG rheumatoid factors with mildly reduced and amidomethylated IgG.

Two broadly defined populations were identified in affinity column-enriched rabbit and human rheumatoid factor (RF) preparations: one population reacted preferentially with mildly reduced and alkylated (MRA) homologous (with regard to species) IgG, and the other reacted preferentially with native, intact IgG. Each of these reactivities was identified by preferential association of RF with either intact or MRA IgG-Sepharose 4B conjugates and existed in both the IgM and IgG immunoglobulin classes. Use of soluble IgG inhibitor preparations in RF- dependent hemolytic and hemagglutination inhibition in RF-dependent hemolytic and hemagglutination inhibition assays showed that the preferred form of IgG inhibitor paralleled the preference of a particular RF preparation for a particular IgG affinity matrix. In addition, preferential reactivity was observed toward either intact or MRA Fc gamma inhibitors. On a molar basis RF reactivity with Fc gamma was significantly less than that observed in the presence of whole IgG. In contrast, neither IgG Fab nor F(ab')2 fragments were reactive with either of the 2 specificity populations of RF. The distribution of immunoglobulin class relative to specificity suggested that preferential reactivity with MRA IgG was usually associated with IgM RF, and reactivity with intact IgG was usually associated with IgG RF. These data suggest that in vivo perturbation of IgG structure may lead to an RF response identifiable by reactivity with an altered monomeric form of IgG.

Serum immunoglobulin and complement levels in tropical pulmonary eosinophilia, and their correlation with primary and their relapsing stages of the illness.

Serum concentrations of IgA, IgG, IgM, IgE, C3 and C4 complement components were estimated in 19 patients with tropical pulmonary eosinophilia (TPE). Thirteen of the patients presented during their first episode of TPE and 6 of them during a relapse of the disease. We found a remarkable elevation of serum IgE level in TPE, which is consistent with earlier reports. In contrast, there was a modest increase in IgM levels and unchanged or even lower levels in IgA and IgG immunoglobulin classes. There seemed to be a direct relationship between IgE level and degree of peripheral blood eosinophilia in TPE. The outstanding finding, however, was a nearly threefold higher mean serum IgE level in patients with relapsing disease as compared to that observed in patients during the primary attack. This is the first reported study of circulating complement components in TPE. A significant rise of serum C3 level was found in these patients; there was no similar elevation of serum C4 component.

Identification and subcellular localization of a sarcoma-associated antigen(s) in a human cell line.

The present investigation was designed to demonstrate and identify the subcellular localization of sarcoma-associated antigen(s) (TAA) in an established human neurogenic sarcoma line (T cell line). Indirect immunofluorescence was used to screen sera from patients with sarcoma, nonsarcoma neoplasias, and from presumably normal blood bank donors. The positive sera were submitted to a series of absorptions to remove possible nonspecific cross-reacting antibodies. The target cells were then studied with electron microscopy, utilizing the indirect immunoperoxidase technique to determine the subcellular localization of the sarcoma-associated antigen(s). Findings indicate that sarcoma-bearing patients have circulating antisarcoma antibodies directed to antigen(s) localized at the surface membrane of T cells. These antibodies pertain to the IgM or IgG immunoglobulin class. The exact nature of the sarcoma-associated antigen(s) identified in this study is not known at the present time. However, the results obtained strongly suggest that these substances may represent a new type of tumor-associated antigen(s).

IgG cold agglutinins and first trimester abortion.

Abstract. Two patients with first trimester abortion and idiopathic cold agglutinin syndrome due to cold auto‐antibodies of the IgM and IgG immunoglobulin classes are reported.Sucrose gradient ultracentrifugation and 2‐mercapto‐ethanol treatment indicated the presence of IgM as well as IgG cold agglutinins.The possible relationship between the abortions and these cold agglutinins is discussed.

Circulating antibodies to cow's milk proteins in ulcerative colitis

Sera from patients with ulcerative colitis (51), Crohn's disease (30), hypolactasia (13), untreated adult coeliac disease (11), irritable colon syndrome (24), and sera from 38 healthy control subjects were tested for antibodies to the principal cow's milk proteins-casein, alpha-lactalbumin, and beta-lactoglobulin. The red-cell-linked antigen-antiglobulin reaction was used to determine the titres of direct agglutinating antibodies and IgA and IgG incomplete antibodies. Apart from patients with coeliac disease, direct agglutinating antibodies were found infrequently and then in low titres. Approximately 50% of subjects had low titres of IgA and IgG antibodies. However, the titres found in sera from patients with ulcerative colitis did not differ from those found in the control subjects or in patients with Crohn's disease, hypolactasia, or irritable colon syndrome. Patients with untreated coeliac disease frequently had high antibody titres to the milk proteins. In all subjects tested, incomplete antibodies of IgA or IgG immunoglobulin class occurred with equal frequency. The frequent occurrence in adults of low titres of antibodies to the milk proteins may be due to continued absorption of minute amounts of protein. Absorption of allergens may be facilitated by mucosal damage, such as that of coeliac disease, with stimulation of antibody production. At the present time, however, there is little evidence to suggest that milk allergy is a factor in the aetiology of ulcerative colitis.

Conversion of Non-Immune Rabbit Spleen Cells by Ribonucleic Acid of Lymphoid Cells from an Immunized Rabbit to Produce IgG Antibody of Foreign Light Chain Allotype

Abstract Spleen cells (SpC) from non-immunized rabbits were converted to antibody “indirect” plaque-forming cells (PFC) by incubating them with ribonucleic acid (RNA) extracts of lymph node cells (LNC) obtained from rabbits 18 to 24 days after they were immunized with several intravenous injections of 4 × 108 sheep red blood cells (SRBC). The RNA extract was inactivated by ribonuclease (RNAse) but not by deoxyribonuclease (DNAse) or trypsin, indicating that the conversion required intact RNA. “Indirect” PFC were developed with optimal amounts of goat anti-IgG-Fc fragment and these were not inhibited by 2-mercaptoethanol (2-ME) or goat anti-IgM but were inhibited by excess anti-IgG-Fc fragment. This indicated that the antibodies produced by the PFC are of the IgG immunoglobulin class. The conversion was specific for the SRBC antigen injected. The light chain allotype of the IgG antibody produced by the PFC was identified by use of anti-b4 and anti-b5 to develop the “indirect” PFC, to visualize the PFC by radioautography and to inhibit plaque formation. Most of the “indirect” PFC of the converted SpC (64% to 84%) possessed IgG antibody with the allotype characteristic of the donor of the RNA extract; some of the “indirect” PFC (4% to 32%) possessed IgG antibody with the allotype characteristic of the donor of SpC. When the “RNA-converted” SpC were lysed by freezing and thawing, the anti-SRBC titer of the lysate, measured by the localized hemolysis in gel technique, was 4096 compared to 4 for lysates from the same number of lysed, nonimmune SpC alone. Moreover, anti-SRBC antibody could not be detected in the RNA extracts. These results indicate that a component of the RNA extract, presumably RNA itself, is providing information for the synthesis of at least part of the IgG antibody molecule.

Genetic and Cellular Factors in the Immune Response

Abstract The antibody response to poly Glu52Lys32Tyr15 was studied in two inbred strains of rats, the highly responding ACI strain and the poorly responding F344 strain. The amounts of antibody formed by the parental strains, the F1 and F2 generations and the backcrosses into the parental strains were assayed by a quantitative immunoadsorbent micro-method. Radio-immunoelectrophoretic studies showed that the antibody response was distributed among the IgM, γ1 and IgG immunoglobulin classes in both males and females. There was no correlation between the quantity of antibody made and the immunoglobulin class. The results of the experiments are consistent with a model in which the genetic control of the antibody response is exercised by at least two independently segregating genes—one for recognition of antigen (R-gene) and one for quantitative control of the amount of antibody formed (Q-gene). In addition, there is a sex influence, which is most clearly seen in the highly responding ACI parental strain and in backcrosses to that strain; it is progressively diminished by increased cross-breeding. The functioning of the sex factor is associated with a higher and more heterogeneous antibody response in females. The effect of antigen dose was studied systematically over a range of 104. The ACI strain made more antibody as the dose of antigen was increased, and the response reached a plateau following immunization with 1.5 mg of antigen. On the other hand, the response in the F344 strain was low and erratic up to a dose of 1.5 mg of antigen; thereafter, the antibody response slowly increased, and all animals made antibody. At very low doses of antigen, the ACI strain made predominantly IgM antibody, and, as the antigen dose increased, all classes of immunoglobulin contained antibody. In contrast, the F344 strain always formed predominantly IgG antibody and very little, if any, IgM antibody. Aggregation of the antigen with methylated bovine serum albumin had different effects on the antibody response in the two strains of rats. The amount of antibody formed by the highly responding ACI strain was decreased or unchanged. The amount of antibody formed by the poorly responding F344 strain was either increased or unaltered. The antibody formed by the F344 strain was almost exclusively in the IgG class, whereas the ACI strain formed antibody in all immunoglobulin classes. The various hybrids of the ACI and F344 strains responded predominantly in the IgG class, in contrast to the findings following immunization with the unaggregated antigen, in which case the antibody response was distributed among all of the immunoglobulin classes. These findings suggest that an inability to make IgM antibody to poly Glu52Lys33Tyr15 may be a factor in the poor response of the F344 strain to immunization with that antigen. The heterogeneity in the magnitude of the antibody response in the ACI strain was greatly restricted, and all animals in the F344 strain responded. Finally, the sex difference in the antibody response was unaltered or enhanced.

Storage stability of different antibody species against arbovirus and rickettsial antigens in blood dried on filter paper discs.

Citrated human bloods containing yellow fever virus hemagglutination-inhi biting (HI) antibodies predominantly in the IgA, IgM or IgG immunoglobulin classes, epidemic typhus agglutinating (MA) antibodies distributed between IgG and either IgA or IgM immunoglobulins and typhus complement fixing (CF) antibodies in the IgG immunoglobulin class were dried on filter paper discs. After sealing in moisture-proof bags, groups of discs were stored at –20, +4, +26 and +37 C. EJuates prepared from the discs at intervals after drying were tested for the recovery of specific antibody activity. Antibody activity attributable to IgM immunoglobulin declined rapidly upon storage, regardless of temperature. Thus, yellow fever HI antibodies belonging to the IgM immunoglobulin class were not detectable in eluates which had been stored for 1 month, even at —20 C. In contrast, antibody activity residing in the IgG immunoglobulin class appeared to be relatively stable on filter paper discs over a 4 month period, especially when stored at lower temperatures. Stability of IgA antibodies requires further study. Interpretation of serologic data obtained from studies employing the filter paper disc technique must take into account differences in storage stability of the various classes of immunogbbulins.

Heterogeneity of Rabbit Anti-Ovalbumin Antibodies Sensitizing Human, Guinea Pig and Rabbit Skin

Summary Three groups of rabbits were injected with five-times recrystallized ovalbumin. One group received soluble ovalbumin, the second alumprecipitated ovalbumin, and the third ovalbumin in complete Freund's adjuvant. The developmental courses of human, guinea pig and rabbit skin-sensitizing antibodies were followed, and representative sera were fractionated by electrophoresis and by Sephadex G 200. The effect of heating at 56°C for 4 hr was also studied. Rabbit anti-ovalbumin antisera are capable of sensitizing human, guinea pig and rabbit skin. A different antibody sensitizes the skin of each of the three species. Human SSA was best stimulated by antigen in Freund's adjuvant, was first detectable at 3 to 4 weeks and peaked at 10 to 12 weeks. It is only alightly affected by heat, is fast-moving electrophoretically and elutes with the ascending 7 S peak from Sephadex G 200. Guinea pig PCA antibody was produced effectively by each immunization technique used, appeared early and continued at high titer for several months. It is heat stable, is slow-moving electrophoretically and coincides with the 7 S peak from Sephadex G 200. Rabbit homologous PCA antibody was best stimulated by alum-precipitated ovalbumin, was demonstrable at 2 weeks and was usually sustained for several months. This antibody is affected but not destroyed by heat, is fast-moving electrophoretically, and elutes with the ascending 7 S peak from Sephadex G 200. The GPPCA appears to coincide with the IgG immunoglobulin class, confirming the results of others (12, 13). The immunoglobulin class or classes of HSSA and RaPCA antibodies have not been identified in these studies, but are fast-moving electrophoretically and are perhaps slightly larger in size than IgG immunoglobulins. In this system, the P-K reaction is not comparable to PCA in the guinea pig.