Non-organ specific thermostable tissue antigens

Thermostable ethanol insoluble antigens (BE antigens) were identified that occur in all human tissues and human dispersed cells, but which are absent from normal human serum. In contradistinction to previously described organ-specific BE antigens, these antigens were referred to as non-organ-specific tissue antigens (NOST). Antisera obtained by immunization of rabbits with BE preparations of human organs had been selected for being devoid of any organ specificity and had been absorbed by BE preparations of pooled human serum. Such antisera could be used as reagents for detection of NOST BE antigens in pathological human sera. Inhibition of enzyme immunoassay proved to be a convenient procedure for these studies. Inhibition of 35% or more was only exceptionally noted in studying sera of normal subjects 20-40 years old, but inhibition exceeding 35% (positive results) was noted in 48% of sera from subjects at the age of 70 years or more. A high incidence of positive results was also encountered in sera of patients with end-stage renal disease (30%), renal graft recipients (18%), and in patients with lymphoma or leukemia (44%), but interestingly enough, no positive tests were noted in patients with lepromatous leprosy.

A competitive ELISA technique for the measurement of von Willebrand factor antigen (vWF:Ag) using staphylococcal protein A peroxidase

A competitive ELISA technique for measurement of von Willebrand factor antigen (vWF:Ag) using Staphylococcal Protein A peroxidase is described. The standard used in this assay is partially purified Factor VIII:C/vWF which has been standardized against a conventional method (electroimmunoassay). The results show a close correlation (correlation coefficient 0.956) as compared to the standard Laurell electroimmunoassay technique. Inter-assay and intra-assay coefficients of variation were less than 5%. The technique is simple to perform and results may be obtained within three hours of specimen collection.

Standardization of house dust mite extracts. Liberation of allergenic and antigenic components in relation to extraction conditions

The spontaneous release of house dust mite components from cultures of Dermatophagoides pteronyssinus into slightly buffered water was studied against time, using both continuous and discontinuous extraction procedures. It was shown that proteins, carbohydrates, IgE binding components and precipitating antigenic components were rapidly released from the house dust mite cultures, reaching a maximal liberation within 1 h of extraction. Repeated extractions of house dust mite cultures (discontinuous extraction) showed an additional release of IgE components but the IgE binding potency declined after successive extractions, while showing increasing release of immunological inactive components. IgE binding to antigens immobilized to polystyrene surfaces (IgE-ELISA) appeared to be less sensitive compared with cyanogen-bromide activated discs (IgE-RAST). It was concluded that extraction procedures of house dust mite cultures with short incubation time of 1 h or less are to be preferred.

Successful immunotherapy for Triatoma protracta-induced anaphylaxis

A successful program of immunotherapy for Triatoma protracta-induced anaphylaxis was developed. This program included a new passive extract-antigen preparation standardized by RAST inhibition. This antigen facilitated the development of a reliable skin test protocol for in vivo diagnosis of Triatoma protracta allergy. Five patients with T. protracta-induced anaphylaxis underwent a rapidly increasing dosage schedule of immunotherapy. The IgE- and IgG-antibody responses during immunotherapy were followed with solid-phase RIA. Protection against anaphylaxis was confirmed in all patients with a "bite challenge" by T. protracta. This is the first report of completely successful T. protracta immunotherapy.

Multitest CMI for standardized measurement of delayed cutaneous hypersensitivity and cell-mediated immunity. Normal values and proposed scoring system for healthy adults in the U.S.A

The Multitest CMI system, a disposable device that simultaneously applies seven standardized preloaded antigens and diluent control, is a major advance for measurement of delayed type hypersensitivity (DTH) in assessment of cell-mediated immunity (CMI). The system was tested in 402 healthy adults, aged 17 to 92 years, to determine normal values for incidence and size of DTH responses. Incidence of positive responses to individual antigens varied from 85% to 46%, with great variability related to age and sex. To better assess CMI, a two-part score based on 48-hour readings was employed. The mean number of positive antigens ranged between four and five, and the mean sum of their mm induration ranged between 18 and 25, with both scores increasing with advancing age. A statistical zone of reduced DTH scores (hypoergy) was identified. The Multitest CMI system appears to be a practical means of reproducibly assessing CMI in subjects with immunologic, metabolic, infectious, or neoplastic disorders. The scores in our population may serve as reference values to which results from any tested adult can be compared.

Quantitation of a highly immunogenic leukocyte antigen (L1) by radioimmunoassay: methodological evaluation

This paper describes a radioimmunoassay (RIA) for the quantitation of a major protein antigen (L1) released from human granulocytes. A protein A-carrying strain of Staphylococcus aureus was used as a solid phase IgG-binding reagent for the separation of antigen-antibody complexes from free antigen in the assay. A two-step version of the RIA may be completed in 2.5 h and has a detection limit of about 5 ng/ml. The sensitivity may be increased by minor modifications. A single step version takes 1.5 h and has adequate sensitivity to cover clinically important plasma levels. Selection and optimal use of reagents for the two-step procedure is described and their storage discussed. The simplicity of the procedure combined with high sensitivity and satisfactory accuracy, precision and reproducibility makes this assay suitable for quantitation of L1 in various body fluids.

IgE responses in human filariasis. II. Qualitative characterization of filaria-specific IgE

Crossed radioimmunoelectrophoresis (CRIE) was used to characterize human IgE antibody responses to filarial parasites by using antigens derived from Brugia malayi (Bm) adult worms. A reference pool of patient sera was initially used to determine the sensitivity and specificity of CRIE. Because IgG-blocking antibodies interfered with IgE binding in certain sera, all sera were preabsorbed with protein A-Sepharose. As little as 50 ng of specific IgE antibody (determined by quantitative radioallergosorbent test [RAST]) in the reference pool bound to 20 of the 35 antigen precipitates in crossed immunoelectrophoresis. Increasing IgE antibody concentration did not increase the number of IgE-binding precipitates. Six patients from each of the three major clinical groups in lymphatic filariasis (i.e., tropical pulmonary eosinophilia [TE], chronic lymphatic pathology [CP], or circulating microfilaremia [MF]) were studied by CRIE with the use of a constant amount of IgE antibody (50 ng IgE anti-BmA). Distinct patterns of allergen recognition were observed among the groups. Individuals with TE recognized both anodic and cathodic antigens as allergens, whereas the other two groups recognized predominantly anodic antigens. The greatest number of allergens was recognized by patients with TE; this number ranged from nine to 18, whereas patients with CP or circulating MF recognized from six to 11 allergens. Although potentiated IgE responses at a quantitative level in parasitic helminth infections is a well-established phenomenon, our studies showing the diversity of antigens recognized as allergens indicate for the first time potentiated IgE responses at a qualitative level as well.

The effect of storage of whole blood on the association of factor VIII-related antigen and factor VIII-coagulant antigen

To evaluate the extent of denaturation of factor VIII-coagulant activity (VIII: C) during production of factor VIII concentrates, the factor VIII-coagulant antigen (VIII: CAg)/VIII: C ratio was measured in plasma, cryoprecipitate and cryosupernatant from fresh and stored blood. This ratio was close to unity for both cryoprecipitate and other concentrates, suggesting that VIII: CAg is lost concurrently with VIII: C during cryoprecipitation and further fractionation. Storage of blood (18 h, 22 degrees C) before processing resulted in a 30% loss of VIII: C from the separated plasma; however, VIII: CAg was not affected. In cryoprecipitate prepared from this plasma, VIII: C and VIII: CAg both were 30% lower than when prepared from fresh plasma. In the corresponding cryosupernatant, however, more VIII: CAg but less VIII: C was present compared with fresh material. Gel chromatography revealed that the rise of VIII: CAg in cryosupernatant prepared from stored blood, was due to an increased amount of VIII: CAg of low molecular weight, not being associated with factor VIII-related antigen. Such an increase in dissociated VIII: CAg was not detected in the plasma prior to cryoprecipitation. It is concluded that during storage of blood, molecular changes are induced in the factor VIII-VWF complex, possibly by limited proteolysis, which make the complex more liable to dissociation during subsequent cryoprecipitation.

Antigenic and allergenic changes during storage of a pollen extract

The changes that occur in the antigens and allergens of a timothy grass pollen extract during storage were measured by radioallergosorbent test (RAST) inhibition, isoelectric focusing, (IEF), crossed immunoelectrophoresis (CIE) and crossed radioimmunoelectrophoresis (CRIE) and a dye-binding protein assay. Storage intervals varied from 7 to 92 days at temperatures of 4 degrees, 22 degrees, and 35 degrees C and the freeze-dried extract was rehydrated and stored in either phosphate-buffered saline with 50% glycerol (PBSG) or Coca's solution (CS). For extracts stored in CS at 35 degrees C, allergenic activity as measured by RAST inhibition dropped by almost one half at 7 days and certain of the IEF, CIE, ad CRIE bands were no longer visible, showing that these properties correlated with allergenic activity. After 65 dys, no IEF bands were visible but three CIE bands could be visualized. At 22 degrees the changes were slower and at 4 degrees C no changes were observed for the 92-day storage time. Extracts stored in PBSG showed some of the same changes but were much more stable at all temperatures. During storage, the protein content as measured by dye binding was also reduced, showing tha proteins were fragmenting. Because some of the allergenic proteins disappeared more rapidly than others, there was not only a loss in total allergenic activity but also a change in specificity. This raises serious questions concerning the use of such extracts, especially for diagnosis.

Further studies on the safety of polymerized antigens for immunotherapy

Six patients receiving immunotherapy with standard aqueous extracts for the treatment of atopic disease were selected from the patient population of Northwestern University Allergy Clinics for continued immunotherapy with polymerized antigens. These six patients could not tolerate quantities of conventional aqueous extracts considered maintenance doses because of immediate-type local or systemic allergic reactions or both to immunotherapy. These six patients were treated with separate preparations of polymerized ragweed (PRW) and polymerized grass (PG), and each of the six patients was rapidly advanced to previously unobtainable maintenance doses of PRW and PG without local or systemic reactions. Treatment with other aeroallergen standard extracts was continued to maintenance dosage without further systemic reactions. In patients highly sensitive to ragweed and grass aqueous extracts, the substitution of these extracts with PRW and PG allows these patients to receive therapeutic immunotherapy injections with decreased risk of immediate-type local and systemic reactions.

Study of guinea pig and human antibodies to toluene diisocyanate

Antibodies to toluene diisocyanate (TDI) have previously been reported in both sensitized guinea pigs and industrial workers. Detection of antibodies to TDI is difficult because the ability of TDI to self-polymerize and cross-link carrier proteins causes problems in preparing satisfactory hapten-protein conjugate antigens. Use of monoisocyanate analogues of TDI for antigen preparation eliminates the problem. This study compared 3 tolyl monoisocyanate isomers with TDI for haptenic ability to detect antibodies to TDI in sensitized guinea pigs and humans. Using the gel-diffusion technique, antibodies from guinea pigs reacted with ortho-, meta- and para-tolyl monoisocyanate haptens and with a TDI hapten. In the guinea pigs, reactions appeared to be strongest with the TDI hapten and weakest with meta-tolyl isocyanate hapten. On the other hand, antibodies in TDI-sensitized workers, as determined by radioallergosorbent testing, reacted comparably with each of the haptens.

Standardization of Factor VIII. II. A British Standard for Factor VIII related antigen

A collaborative study on factor VIII related antigen (VIII R:Ag) has been carried out, involving 11 laboratories in the U.K. Samples of two different freeze-dried plasmas were assayed against participants' own local standards by the Laurell electroimmunoassay method. There was reasonably good agreement on the relative potencies of the two freeze-dried plasmas, but there were considerable differences in the VIII R:Ag content of the plasma pools used as local standards, with values ranging from 83% to 129% of the mean. All participants agreed on the need for a standard for VIII R:Ag, and that the unit be defined by the mean of the local standards. Accordingly, freeze-dried plasma 66/355 was established as the 1st British Standard for factor VIII related antigen, with an assigned potency of 1.05 units per ampoule.

Studies on the deterioration of antigen E in extracts of Ambrosia elatior

Five per cent (w/v) extracts of defatted Ambrosia elatior pollen were prepared in bicarbonate-buffered saline (Coca's extract) and Coca's extract with 50% glycerol (Gly-Coca's extract). Sterile extracts were stored in untreated glassware and glassware coated with silicone. Stock extracts were diluted in phosphate-buffered saline (PBS) and stored at 5 +/- 3 degrees C. Extracts 1:20, 1:40, and 1:400 were assayed at approximately 6-wk intervals for antigen E. Quantitative determinations were made by modified double diffusion in agarose gels using known standards of antigen E for comparison. Results from the first year of this 3-yr study show no significant reduction in 1:20 Gly-Coca's extracts and a highly significant reduction of antigen E in 1:20 Coca's extracts. Further analysis of variance indicates significant reduction in all 1:40 and 1:400 extracts. Differences in the initial extracting solvents did not significantly affect these more dilute extracts. No significant differences were observed in the untreated and silicone-coated glassware. In terms of per cent antigen E reduction, 1:20 Gly-Coca's showed negligible reduction and Coco's at 1:20 declined nearly 50% in antigen E content. Extracts stored at 1:40 retained only 40% of the original antigen E content, while diluted extracts stored at 1:400 retained only 35% of the initial antigen E after 1 yr of storage at 5 +/- 3 degrees C.

[Effect of the conditions of coupling in testosterone-albumine conjugates on the quality of the antibodies produced in the rabbit]

In order to produce antibodies against small molecules as steroid hormones a necessary step in the preparation of the antigen includes a covalent linkage of the hapten to a "carrier" protein. Two coupling procedures (mixed anhydrid method and carbodiimide method) have been utilized in the preparation of testosterone conjugate linked in the C3 position. The same batches of testosterone (o-carboxy methyl) oxime and crystallized bovine serum albumine have been used. In the 2 different antigens the steroid/BSA molar ratio was identical (30). Antibodies have been raised in female New-Zealand rabbits. It is concluded that experimental conditions of covalent linkage influenced the antigenic potency of the conjugate used. Antibodies of considerably higher titer, capacity and affinity were obtained when the mixed anhydrid method was used. However the specificity of these antibodies did not appear to be influenced by the type of antigen used.

Radioimmunoassay for rhesus monkey gonadotropins

Heterologous double-antibody radioimmunoassay methods are described for the measurement of circulating levels of rhesus monkey (Macaca mulatta) FSH and LH; the latter assay is also applicable to rhesus chorionic gonadotropin (CG) estimations. The FSH assay utilizes purified rat FSH for trace, either of two anti-human FSH antisera and a semipurified rhesus pituitary standard. The LH assay utilizes purified ovine LH for trace, an anti-human CG antiserum and the same rhesus pituitary standard. The use of these systems obviates the necessity of purifying rhesus gonadotropins which are required for the development of homologous radioimmunoassay systems.

Determination of plasma and tissue levels of tyramine by radioimmunoassay

Antibodies were prepared against tyramine. The antigen was prepared as follows: p-Aminohippuric acid was coupled to mBSA using a carbodiimide reagent. The amino group was diazotized an attached to the aromatif ring of TYR. The immunogen in Freund's complete adjuvant was injected into rabbits. The specificity of the resulting antibody was determined by radioimmunoassay. Using random-labeled TYR-3H, TYR, its metabolites, phenethylamine analogs, catecholamines, and certain amino acids were evaluated by a competitive binding assay method. With this technique 4 ng of TYR inhibited the binding of TYR-3H by 50%. The radioimmunoassay of TYR was used to measure the plasma, urine, and tissue levels of TYR in rabbits. The plasma disappearance curve of TYR revealed a biphasic pattern with t1/2 of 2 min and 54 min. The highest concentration of TYR was found in adrenals and spleen. The factthat the major metabolites of TYR and a series of pharmacologically important sympathomimetics and catecholamines did not interfere, makes the radioimmunoassay of TYR a useful, simple, sensitive, and spedific method for the direct analysis of TYR in biological meterials.

Divergent results in radial immunodiffusion with antisera differing in precipitation properties with respect to individual immunoglobulin subclass. I. The antigen factor

Two bovine IgG subclasses were used as reference antigens to study subclass influence on radial immunodiffusion results with total bovine IgG. In combination with some of eight anti-bovine IgG sera tested the use of the same antiserum with one subclass furnished values which were about twice as high as values obtained with the other subclass. It is concluded that immunoglobulin determinations by radial immunodiffusion are influenced by the chosen reference antigen and by subclass ratios in the samples tested. The composition of immunoglobulin subclass mixtures for testing antisera used in radial immunodiffusion is discussed.

[Preparation of a standardized antigenic extract from several strains of African trypansomes]

The preparation of a soluble antigen from african trypanosomes is described below. It is important to observe the following steps: --minimal dose of the phytohemagglutinin must be placed in rapid contact with the trypanosomes; --the standard speed of the different centrifugations must be strictly observed; --a thorough washing of the trypanosomes must be carried out to eliminate the hetero-antigens, but caution should be excercised, as over washing is harmful to the Trypanosomes.

Color-coded antigen for the automated reagin test for syphilis

A low-cost, color-coded antigen was developed for the Automated Reagin Test. A comparative study with 3,000 sera showed a sensitivity somewhat greater than the Rapid Plasma Reagin Card antigen. Samples could be traced back by using a specific color-coded antigen on a given autoanalyzer.

Radial immunodiffusion of chicken serum proteins. I. Standardization of optimal test procedures

Optimal conditions were determined for the quantitaion of chicken serum albumin, conalbumin, IgG and IgM by the radial immunodiffusion test. The best diluent was 0.15 M phosphate buffered saline, pH 7.2. The optimal concentration of the rabbit antiserum in the agar plate was inversely related to the molecular weight of the protein under study. The incubation time required for maximum ring formation was directly related to the molecular weight of the proteins under study. The reproducibility of the tests was evaluated using stored and fresh antiserum-agar plates.