Human Serum IgA Research Articles

CONCENTRATION OF SERUM-IMMUNOGLOBULINS IN HEALTHY YOUNG ADULT MALES ESTIMATED BY ASSAY AGAINST THE INTERNATIONAL REFERENCE PREPARATION

IgG, IgA, and IgM in sera from healthy young adult males from eleven different countries were assayed against a standard related to the international reference preparation for human serum immunoglobulins IgG, IgA, and IgM. The results, which are expressed in international units per ml., provide a basis for the establishment of ranges of normal values for these proteins and for comparisons of levels between different populations.

Manual Nephelometric Methods for Immunochemical Determination of Immunoglobulins IgG, IgA, and IgM in Human Serum

Abstract Manual procedures are presented for determining immunoglobulins IgG, IgA, and IgM in human serum. The three immunoglobulins are quantitated, after reaction with specific antisera, by measuring light scattering by the antigen-antibody complexes. The procedure is standardized by use of pooled human serum with known concentrations of IgG, IgA, and IgM. Results with the present system correlated excellently with results of either radial immunodiffusion or an automated immunochemical procedure. Precision of duplicate determinations for the IgG, IgA, and IgM methods is 5.37, 1.30, and 5.36% (CV), respectively.

The carbohydrate composition of J chain from human serum and secretory IgA

J chains prepared from human serum IgA and human secretory IgA both contained 7.6% total carbohydrate. The monosaccharide compositions were similar and on the basis of a molecular weight of 26 000 each J chain contained 1 mole fucose, 3 moles mannose, 2 moles galactose, 3–4 moles glucosamine and 1 mole of sialic acid.

Measurements of Concentrations of Human Serum Immunoglobulins

Abstract Concentrations of immunoglobulins in human serum are frequently measured for both clinical and research purposes, and the values have been expressed in terms such as milligrams/milliliter. However, there has been little confidence that concentrations, as estimated by different laboratories using different reference materials, are comparable. With the object of improving the uniformity of estimates by different laboratories, a freeze-dried preparation of human serum, coded 67/86, has been assessed for use as a standard for measurements of human serum immunoglobulins IgG, IgA and IgM by techniques of immunodiffusion (1). Part of this batch of material has been established by the World Health Organization1 as the International Reference Preparation of Human Immunoglobulins IgG, IgA and IgM, and international units have been assigned to it such that each ampule of the International Reference Preparation contains on average 100 IU of IgG, 100 IU of IgA and 100 IU of IgM.

Comparison of the Effect of Elastase on Human Secretory IgA and Serum IgA

Abstract During the last several years three papers were published on the effect of pancreatic elastase on immunoglobulins (1–3). De Vaux St. Cyr and Heremans (1) reported that digestion of human IgG with elastase yielded two fragments which they believed to be similar to the Fab and Fc produced by trypsin digestion of IgG, and Waller et al. (3) demonstrated that the two fragments resulting from elastase digestion of IgG gave a reaction of identity in gel diffusion studies with the Fab and Fc obtained by papain digestion. To date there has been no report on the effect of elastase digestion on serum IgA or secretory IgA. Recent studies (4–7) have suggested that human secretory IgA is less susceptible to proteolytic degradation than serum IgA. The following investigation was undertaken in order to compare the effect of elastase digestion on these two immunoglobulins. Materials and Methods. Secretory IgA was prepared from colostrum obtained 1 to 4 days postpartum.

Automated Immunochemical Procedures for Measurement of Immunoglobulins IgG, IgA, and IgM in Human Serum

Abstract Automated continuous-flow procedures have been developed for microdetermination of immunoglobulins IgG, IgA, and IgM in human serum. The three immunoglobulins are measured by reactions with specific commercial antiserum, and standardized by use of pooled human serum containing known concentrations of IgG, IgA, and IgM. Values determined for the immunoglobulins by the automated procedures correlate with values obtained by radial immunodiffusion. The precision of replicate determinations for the IgG, IgA, and IgM methods is 3.64, 5.11, and 6.00% (CV), respectively.

IgA and Other Immunoglobulins from the European Hedgehog

Abstract Hedgehog serum and exocrine secretions contain, besides IgM and two subclasses of IgG, a protein which cross-reacts with an antiserum against human IgA. Hedgehog serum IgA comprises a large proportion of molecules having a molecular size in the range of the 9 to 10S dimer of a 7S unit. The electronegative charge of hedgehog's serum IgA resembles that of human serum IgA as shown by its behavior upon DEAE-chromatography and electrophoresis. IgA was found to be the immunoglobulin having the highest secretion-to-serum concentration ratio in saliva and bile, and also to be the immunoglobulin produced by the majority of plasma cells in the lamina propria of the hedgehog's intestinal mucosa.

Electron microscopy of human and mouse myeloma serum IgA

The structure of a human serum myeloma IgA and a mouse myeloma IgA, MOPC 315, were examined by electron microscopy. The purified dimers, consisting of two 7 s subunits, appeared as a double “Y”. Polymers showed radial arrangement of the “Y” shaped 7 s subunits. The “Y”-shaped monomeric structures were assembled radially via Fc linkages to give the polymeric forms.

Secretory IgA in Human Serum

Abstract Secretory component (SC) was detected by the radioactive single radial diffusion technique in nearly all sera examined. The SC was shown to be associated with polymeric serum IgA. The mean level of secretory IgA (SIgA) in normal sera from India, Africa and Europe was about 0.03 to 0.04 mg/ml. The mean level was elevated in patients with a variety of disorders involving secretory surfaces (e.g., acute bacterial enterocolitis or respiratory tract carcinoma), but also in disorders with no known involvement of secretory surfaces. The highest levels were seen in lactating women, with a mean level five times higher than that in the general population. SIgA was also found at lower levels in cord serum, serum from breast-fed newborns and serum from children 3 to 10 years old.

The 11-S sow colostral immunoglobulin isolation and physicochemical properties

1. 1. An immunoglobulin that is not present in porcine serum has been isolated from sow colostrum by chromatography on Sephadex G-200 and DEAE-Sephadex A-50, followed by preparative ultracentrifugation in a 10–40% sucrose density gradient. 2. 2. Sedimentation velocity studies on this purified protein yield an s° 20, w value of 11.2 S which is similar to the s° 20, w of human secretory IgA. 3. 3. The sow colostral 11-S immunoglobulin does not have the resistance to reductive cleavage that is a characteristic of human 11-S secretory IgA. Treatment with 0.2 M β-mercaptoethanol results in almost complete dissociation of the 11.2-S molecule to subunits with an s 20, w of 6.5 S. 4. 4. The relationship of the isolated sow colostral 11-S immunoglobulin to human serum IgA is evidenced by its immunologic reaction with specific antiserum to human IgA and by its lack of immunologic reaction with specific antisera to human IgG and IgM.

Quantitative determination of serum immunoglobulin levels by single radial immunodiffusion

Single radial immunodiffusion according to Mancini was used for quantification of the immunoglobulins IgG, IgA, and IgM in human serum. The essential differences between the Mancini and the Fahey techniques are discussed, and several fundamental considerations on the principles underlying the method are given. According to the evidence presented, S0—the point at which the doseresponse line intersects the ordinate when extrapolated to antigen concentration zero—can vary between antisera used for the same test serum, just as it was already known to vary between immunoglobulins of the same class having different antigenic determinants. One case showing this last phenomenon is mentioned. The results of recovery experiments suggest that non-reacting proteins introduced into the antigen well together with the test antigen (as is done in practice for the determination of protein levels in serum) can, in the case of IgA, influence the quantitative results. The coefficient of variation of the immunoglobulin determinations in one batch of test serum repeatedly quantified in the course of ten months, was taken as the measure for the reproducibility of the method. This coefficient was 8.5% for IgG, 5.8% for IgA, and 4.4% for IgM. The immunoglobulin levels in this test serum lay in the middle range of the calibration lines. The accuracy of the method increases with the height of the calibration line. The results are given as percentage of the immunoglobulin levels of a pooled reference serum. This reference serum was calibrated for absolute immunoglobulin concentrations several times, but the results were not sufficientlyreproducible to permit their use as absolute values in place of the relative values.

Quantitative determination of serum immunoglobulin levels by single radial immunodiffusion

Single radial immunodiffusion according to Mancini was used for quantification of the immunoglobulins IgG, IgA, and IgM in human serum. The essential differences between the Mancini and the Fahey techniques are discussed, and several fundamental considerations on the principles underlying the method are given. According to the evidence presented, S0—the point at which the doseresponse line intersects the ordinate when extrapolated to antigen concentration zero—can vary between antisera used for the same test serum, just as it was already known to vary between immunoglobulins of the same class having different antigenic determinants. One case showing this last phenomenon is mentioned. The results of recovery experiments suggest that non-reacting proteins introduced into the antigen well together with the test antigen (as is done in practice for the determination of protein levels in serum) can, in the case of IgA, influence the quantitative results. The coefficient of variation of the immunoglobulin determinations in one batch of test serum repeatedly quantified in the course of ten months, was taken as the measure for the reproducibility of the method. This coefficient was 8.5% for IgG, 5.8% for IgA, and 4.4% for IgM. The immunoglobulin levels in this test serum lay in the middle range of the calibration lines. The accuracy of the method increases with the height of the calibration line. The results are given as percentage of the immunoglobulin levels of a pooled reference serum. This reference serum was calibrated for absolute immunoglobulin concentrations several times, but the results were not sufficientlyreproducible to permit their use as absolute values in place of the relative values.

Quantitative determination of serum immunoglobulin levels by single radial immunodiffusion

Single radial immunodiffusion according to Mancini was used for quantification of the immunoglobulins IgG, IgA, and IgM in human serum. The essential differences between the Mancini and the Fahey techniques are discussed, and several fundamental considerations on the principles underlying the method are given. According to the evidence presented, S0—the point at which the doseresponse line intersects the ordinate when extrapolated to antigen concentration zero—can vary between antisera used for the same test serum, just as it was already known to vary between immunoglobulins of the same class having different antigenic determinants. One case showing this last phenomenon is mentioned. The results of recovery experiments suggest that non-reacting proteins introduced into the antigen well together with the test antigen (as is done in practice for the determination of protein levels in serum) can, in the case of IgA, influence the quantitative results. The coefficient of variation of the immunoglobulin determinations in one batch of test serum repeatedly quantified in the course of ten months, was taken as the measure for the reproducibility of the method. This coefficient was 8.5% for IgG, 5.8% for IgA, and 4.4% for IgM. The immunoglobulin levels in this test serum lay in the middle range of the calibration lines. The accuracy of the method increases with the height of the calibration line. The results are given as percentage of the immunoglobulin levels of a pooled reference serum. This reference serum was calibrated for absolute immunoglobulin concentrations several times, but the results were not sufficientlyreproducible to permit their use as absolute values in place of the relative values.

The immunoglobulins of the dog—II. The immunoglobulins of canine secretions

IgA was found to be the predominant immunoglobulin in canine milk, saliva, tears, hepatic bile and intestinal fluid. The molecular size of canine serum IgA was larger than that of human serum IgA, whereas the molecular size of canine exocrine IgA was similar to or slightly larger than that of 11 S human milk IgA. Both exocrine and serum IgA from the dog were readily and completely reduced to subunits of the size of human IgG by treatment with 0·1 M mercaptoethanol.

IgA immunoglobulin from porcine serum

The isolation and immunologic characterisation of a porcine serum immunoglobulin is described. The isolated protein is shown to be distinct from IgG 1, IgG 2 and IgM but to share antigenic determinants with a colostral immunoglobulin, thought to be equivalent to human secretory IgA, which possesses additional determinants. It is suggested that the isolated serum immunoglobulin is equivalent to human serum IgA and that the pig possesses an IgA system analogous to that found in man.

Anaphylactic transfusion reactions associated with anti-IgA antibody.

A patient had anaphylactic transfusion reactions when transfused with small amounts (10 ml or less) of blood from four consecutive donors. Antibodies to erythrocytes or leukocytes could not be found, but a precipitating antibody reactive with IgA in donor and normal human serum was discovered in the patient's serum. This antibody, which was of the IgG class, fixed complement, and its concentration decreased and then increased after one of the reactions. We postulate that an antigen–antibodycomplement interaction releases kinins that mediate a characteristic anaphylactic reaction. This case illustrates that antibodies reactive with plasma protein antigens should be considered as a cause of transfusion reactions when antibodies to cellular constituents in blood cannot be demonstrated.