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Biomedical subjects

L Perelmutter

Publications and source records attributed to L Perelmutter.

At least 19 recordsLinked to original sources

In vitro IgM and IgM rheumatoid factor production in response to Staphylococcus aureus Cowan I: evidence for the role of Leu-2-positive T suppressor cells and radiosensitive T helper cells.

Staphylococcus aureus Cowan I (SAC) is a potent stimulus of B cell proliferation and differentiation, the latter being T cell-dependent. It has been suggested that immunoglobulin and IgM rheumatoid factor (RF) production in response to SAC involves radiosensitive T helper cells. We studied normal peripheral blood mononuclear cell (PBMC) cultures to assess the roles of radiosensitive T cells and Leu-2 positive suppressor cells in the cellular control of SAC-stimulated IgM and IgM RF responses. Depletion of Leu-2 positive T cells from reconstituted autologous PBMC cultures resulted in an increase in SAC-stimulated IgM production in the majority of individuals, implying the involvement of Leu-2 positive suppressor T cells in this system. Suppression by Leu-2 positive cells is less evident in the SAC-induced IgM RF response, suggesting qualitative differences between IgM and IgM RF SAC-stimulated responses in PBMC cultures from the same normal individuals. Irradiation (1000 rads) of the T cell-enriched subpopulation, either with or without Leu-2 positive cell depletion, resulted in statistically significant decreases in IgM and IgM RF production in response to SAC in reconstituted autologous cultures, providing further evidence of a Leu-2 negative radiosensitive sheep-cell rosetting cell active in in vitro SAC responses. In contrast, PWM-stimulated PBMC cultures showed almost exclusively increases in total IgM and IgM RF production when T cells were irradiated (1000 rads) before culture, consistent with the radiosensitive T suppressor cell involved in the in vitro immunoglobulin responses to PWM. The same five out of nine individuals produced IgM RF, under different culture conditions, in response to PWM and SAC, suggesting that the ability of an individual to produce IgM RF lies intrinsically within the B cell.

Adult

Development of a reverse enzymoallergosorbent test (REAST) to detect timothy-specific IgE antibodies. Comparison with RAST.

Radioallergosorbent test (RAST) for the measurement of IgE antibodies has been introduced more than 15 years ago and a number of technical modifications have since improved its sensitivity and reproducibility. The test has been applied to the diagnosis of allergy and to determine changes in the levels of IgE antibodies following immunotherapy. However, specific IgG antibodies are raised during such a therapy and can interfere with the RAST. We have developed a reverse enzymoallergosorbent test (REAST) where microtiter plates are first coated with a purified polyclonal anti-IgE antibody, then with the serum to test and finally with peroxidase-labeled antigen. This assay is antigen specific as shown by the significant inhibition of binding of the labeled antigen in presence of unlabeled specific antigen (greater than 95%) and the absence of inhibition in presence of irrelevant antigens. The values found in atopic patients (85 subjects) were significantly higher than in the non-atopic donors (35 subjects) (1.14 U +/- 1.20 vs. 0.01 U +/- 0.02, P less than 0.0005) and there was a good correlation with the Pharmacia RAST (P less than 0.0005). The levels of specific IgE by both REAST and RAST correlated well with the clinical symptomatology.

Allergens

IgE-mediated allergy to peanut, cow's milk, and egg in children with special reference to maternal diet.

Nineteen children with IgE-mediated allergy associated with strongly positive prick skin tests and RASTs to peanut or cow's milk and/or egg were studied. Seventeen of the children had been breast fed, ten had been exclusively breast fed for a minimum of 5 months. Reactions to these foods occurred on first exposure to the food in all but one instance, suggesting that in 18 instances sensitization had occurred antenatally or via the breast. A retrospective inquiry indicated that most of the mothers had had a generous intake of the food(s) to which their children were sensitized, but mothers of sensitized children did not consume more of these foods than the mothers of non-sensitized children; moreover, avoidance of the foods (peanut in two instances and egg in one) did not ensure freedom from sensitization to peanut and/or egg. Breast feeding by itself cannot be guaranteed to protect against the development of food allergy.

Anaphylaxis

Effect of antigen stimulation on antigen-specific IgE-plaque-forming cells from peripheral-blood lymphocytes of atopics.

In the present study, it was shown that allergen challenge in vitro produced an increase in the number of antigen-specific IgE-plaque-forming cells of peripheral-blood lymphocytes from grass- or ragweed-allergic patients. Thus, the blood lymphocytes of all twelve (four rye grass I and eight AgE) sensitive donors responded whereas the blood lymphocytes of five non-atopic controls were unresponsive to antigen challenge. Allergen challenge doses of 10(-10)-10(-12) g/ml were found to give the greatest number of plaque-forming cells whereas the number of plaque-forming cells at challenging doses between 10(-9) and 10(-7) g/ml were either the same or less than those obtained with unchallenged cells. The results are discussed as to whether this in vitro model system represents in vivo response to allergen of the allergic patient.

Antibody-Producing Cells

Detection of antigen-specific IgE-plaque-forming cells from peripheral-blood lymphocytes of ragweed- and grass-allergic patients.

The reverse haemolytic plaque assay was developed to measure antigen (AgE or rye grass I)-specific IgE-plaque-forming cells from the peripheral-blood lymphocytes of ragweed- and grass-allergic patients. The anti-IgE-developing antisera was shown to be isotype-specific, and the response of the assay was inhibited by 52% by the addition of 10 pg of antigen. In addition, the assay was shown to have a reproducibility (s.d.) of 15%. The blood lymphocytes from all fifteen atopic (grass and ragweed) patients were shown to form antigen-specific IgE-plaque-forming cells during the pollen season (mean value 115 cells) and up to 6 months after the season (mean value 56 cells). Cycloheximide appears to block the formation of the plaque-forming cells. This method appears to be sensitive and reproducible enough to study in vitro IgE antibody synthesis of peripheral-blood lymphocytes from atopics.

Antibody Specificity

A study on IgE antibody-producing cells from the peripheral blood lymphocytes of atopic patients.

In the present study, the peripheral blood lymphocytes (PBL) of six rye-grass and 22 ragweed atopic patients demonstrated secretion of IgE antibody from 7-day cultures as measured by a sensitive ultra-low RAST. The RAST binding ranged from 1.5% to 21% whereas the cell supernatants from the PBL of eight non-atopic individuals showed little or no response (1.2%). The addition of antigens (rye grass 1 or AgE) or interleukin (IL-2) to the cultures on day 0 failed to cause an increase in response. But examination of PBL from four of these patients by a reverse hemolytic plaque assay showed that challenge of these cells by antigen or IL-2 caused an increase in the number of antigen-specific IgE plaque forming cells. The bulk of the IgE antibody secreting cells were located in a sheep red blood cell rosetted fraction (cell fraction 2) whereas most of IgE antibody PFC were found in the non-rosetting fraction (cell fraction 1). It appears that the reverse hemolytic plaque assay detects IgE antibody-producing cells which can still undergo immune regulation and may represent an earlier stage of B cell differentiation whereas the ultra-low RAST appears to measure spontaneous plasmablast cell IgE antibody response.

Antibody-Producing Cells

Immunoglobulin E response during viral infections.

One hundred and three patients (90 nonatopics and 13 atopics) with respiratory infections to various viral agents were studied retrospectively with respect to IgE immunoglobulin levels during acute (1 to 7 days) and convalescent (8 to 30 days) phases of infection. It was found that 59% of patients had a decrease of 20% or more in IgE level, 27% remained the same, and only 14% showed a rise 20% or more from the acute to the convalescent phases of infection. IgE levels decreased up to 3 to 4 wk after symptoms and the degree of decrease was more apparent for the nonatopics who had higher IgE levels in their acute phase of infection. Less dramatic decrease in IgE was observed for the 13 atopics studied. The changes in IgE levels during the viral infectious period are discussed in terms of possible cellular mechanisms that may control IgE immunoglobulin.

Acute Disease

Possible role of IgG4 in discordant correlations between intracutaneous skin tests and RAST.

Comparison of intracutaneous skin tests and RAST in 2 groups of patients, one consisting of 16 individuals having multiple allergies to pollen, mold and animal dander and the other of 10 patients allergic to mold only, revealed that skin tests were more sensitive than RAST. Skin reactions of 3+ to 4+ were frequently associated with negative RAST results. This was observed more so in mold-allergic patients. In a few cases (6%) RAST showed 2+ reactions while the skin tests were negative. Leukocytes from allergic individuals who had positive skin tests and negative RAST released a significant amount of histamine upon challenge with specific allergen as well as antihuman IgG4, suggesting that this immunoglobulin is a functional component of some immediate hypersensitivity reactions.

Adult

A study on the IgE levels of military recruits and association with HLA antigens.

To identify antigen marker(s) on lymphocytes for the immunoregulation of IgE immunoglobulin. For this purpose, IgE determinations were performed on 58 recruits who were arbitrarily selected for HLA typing. Thirty-three recruits with IgE values ranging from 24 to 142 U/ml (71 U/ml (71 U/ml average) showed a slight increase in incidence for HLA-A23, -A33 and BW-15 when compared to a group of 25 recruits whose IgE values ranged from 153 to 2128 U/ml (615 U/ml average). Examination for C-loci specificity indicated that CW-1, CW-3 and CW-4 similar for both groups; however, the "low" IgE group had a frequency of 55.5% of recruits possessing CW-2 antigen compared with only 15% for the "high" group. The value for the "high" IgE appears to be similar to that of the normal population (10% incidence) and only slightly elevated when compared to 7% (2/29) found when the identical CW-2 antisera were tested with laboratory personnel. Thus the associations of HLA-CW2 with the recruits within the "low" IgE group suggests that this HLA marker may be an expression for a suppressed response for IgE immunoglobulin. Viral and bacterial infections, found frequently in these recruits, are discussed as a possible cause of this suppression.

HLA Antigens

Viral infections and IgE levels.

Six non-atopic patients with respiratory infections to a variety of viruses demonstrated a consistent drop in IgE levels (35% to 87%) in the convalescent phase compared to the acute phase of infection, suggesting that the viral agent affects T lymphocytes to suppress and hence B lymphocytes to secrete IgE immunoglobulin.

Asthma

Allergy testing.

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Animals

Inhibition of reagin-mediated PCA reactions in monkeys and histamine release from human leukocytes by human IgG4 subclass.

Human myeloma proteins of IgG4 subclass in contrast to myeloma proteins IgG1, IgG2 and IgG3, were capable of blocking PCA reactions in monkeys mediated by human reaginic antibodies of IgE class. In addition to IgE, IgG4 myeloma protein was also capable of sensitizing leukocytes from normal individuals and gave histamine release (HR) upon challenge with anti-human IgG4. Leukocytes from 11 allergic individuals and from 9 normal subjects sensitized with the serum of allergic patients, were capable of releasing histamine with anti-human IgG4, anti-human IgE, and the specific allergen. No response was obtained with anti-human IgG1 and IgG3 sera. Leukocytes from the normal individuals released histamine from 3 to 20% with anti-human IgG4 and from 6 to 30% with anti-human IgE. Moreover, normal leukocytes sensitized with IgG4 myeloma protein or a serum of an allergic patient heated at 56 degrees C for 2 h, released a significant amount of histamine on challenge with anti-human IgG4 whereas no response was obtained with anti-human IgE. The biological role of human IgG4 in immediate hypersensitivity reactions is discussed in relation to human IgE.

Animals

An electron microscope study of receptor site on rat mast cells for human immunoglobulin E.

Previous studies using immunofluorescence and autoradiography demonstrated the presence of specific immunoglobulin E (IgE) receptors on rat mast cells (RMC). This finding was confirmed by the use of transmission electron microscopy (TEM) combined with X-ray microanalysis (XMA) employing ferritin labelled antisera XMA was used to detect ferritin as Fe in the target cells. On examination by TEM and XMA, 25 per cent of RMC showed a dense area of Fe deposits on the surface of the cells. No Fe could be detected on neutrophils or eosinophils or in the control cell preparations without human IgE. The Fe was concentrated in well-defined areas of the treated mast cells and this distinct concentration of receptor sites was similar to that observed by other investigators who have termed this phenomenon, "cap" formation.

Animals