PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Desensitization, Immunologic”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed1991

Studies of desensitization and cross-desensitization to immunologic and nonimmunologic stimuli that evoke contraction and histamine release in superfused guinea pig trachea.

This study examined the possibility that there is cross-desensitization between immunologic and nonimmunologic stimuli that evoke contraction and histamine release (HR) in the isolated guinea pig trachea. Compound 48/80 and D-tubocurarine were found to cause homologous and heterologous desensitization for both contraction and HR from superfused trachea. Specific antigen challenge of trachea obtained from animals sensitized with either IgG1 (ovalbumin [OA]) or IgE (oxazalone-human serum albumin [OX-HSA]) also resulted in homologous desensitization for both contraction and HR. However, in experiments with animals sensitized with both IgG1 and IgE antibodies, prechallenge with OA resulted in cross-desensitization to OX-HSA, whereas the reverse sequence was ineffective in eliciting this phenomenon. This may be related to the type of desensitization produced by each antigen (specific versus nonspecific) or to heterogeneity of mast cells in the tissue. Prechallenge of the trachea with compound 48/80 or D-tubocurarine failed to alter subsequent effects of antigen after active sensitization with OA or passive sensitization with either IgG1 or IgE antibodies. Small but statistically significant decreases in tracheal responses to D-tubocurarine were observed after antigen prechallenge to active both IgG1 and IgE antibodies. This is the first study to demonstrate a cross-desensitization between compound 48/80 and D-tubocurarine and the first to examine cross-desensitization with IgG1 and IgE antibodies in the guinea pig trachea. The overall conclusion is that there is no major overlap in the desensitization mechanisms between immunologic and nonimmunologic stimuli in the guinea pig trachea.

Animals↗
PubMed1989

[Effects of desensitization and immunologic changes in patients with allergic asthma].

The allergic dermal tests were carried out in 122 patients who were treated from June 1987 to August 1988. The positive rates for mycomutacapitis, myco-root-black, dust mite and artemisia pollemo were 37.5%, 34.5%, 34.2% and 21.88% respectively in inhaled antigens used for skin test. The positive rates for sesame, peanut, allium and garlic were rather high in food antigens used for skin test. The serum IgE and the total IgE tested by BA-ELISA and human basophil degranulation test (HBDT) were observed in 68 patients with allergic asthma and 52 healthy persons. It was found that the positive rate of BA-ELISA (82.35%) and HBDT (84.70%) coincided well with the dermal test. There was significant changes in serum level of the specific IgE and the total IgE before and after desensitizing therapy with the dust mite dermotaphagoides for 6 months (P less than 0.001).

Allergens↗
PubMed1990

Selective desensitization to seminal plasma protein fractions after immunotherapy for postcoital anaphylaxis.

A 24-year-old white woman reported sexual intercourse-related pruritus, hives, wheezing, and dyspnea within 5 minutes after ejaculation. Systemic reactions (SRs) were prevented by use of condoms. Prick testing confirmed sensitization to five Sephadex G-100-separated fractions of her husband's seminal plasma. The intradermal end point threshold concentrations (ETC) were 10(-4) and 10(-1) micrograms of protein per milliliter to fractions 2 and 3, respectively. Leukocyte histamine release studies exhibited 100% release to fraction 2 and 37% release to fraction 3. A 2-day protocol of rapid immunotherapy (IT) was performed with subcutaneous incremental doses of human seminal plasma (HuSePl) fractions 2 and 3. The patient experienced an SR after receiving a cumulative dose of 38.55 micrograms of fraction 2 on day 1. On day 2, rapid IT with fraction 2 was administered until the patient experienced a mild SR after having received a cumulative dose of 102.8 micrograms. There was a one-log10 increase in the intradermal ETC to both fractions 2 and 3 at the end of day 2. IT was continued three times weekly for 4 months until the patient tolerated 100 micrograms doses of both fractions 2 and 3. At 4 months, coitus was resumed without SRs, and HuSePl IT was stopped. The intradermal ETC to fractions 1, 3, 4, and 5 was increased 6 months after cessation of HuSePl injections, but there was a one-log decrease in the ETC to fraction 2. Our experience demonstrated that systemic tolerance can be achieved by parenteral administration of selected HuSePl fractions. Partial immunologic desensitization of patients with anaphylactic sensitivity can be achieved.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1976

A prospective study on some immunological changes occurring in the first year of grass pollen desensitization.

Some immunological parameters were followed up during the first year of grass pollen desensitization in 15 patients. The skin reactions with grass pollen extract in a series of tenfold dilutions were diminished in all patients during treatment. In nearly all patients a distinct increase in blocking antibody titre was seen. Serum reagin titres as measured by RAST remained constant or decreased somewhat during desensitization. No significant correlations between all three parameters could be demonstrated.

Allergens↗
PubMed1989

Suppression of experimental allergic encephalomyelitis by COP1--relevance to multiple sclerosis.

The evidence in this presentation clearly indicates that in the case of the model disease EAE, desensitization procedures are effective in suppressing the symptoms of the disease and in providing protection against it. The antigens used in our studies are all synthetic materials immunologically relevant to the myelin encephalitogenic protein, but not encephalitogenic themselves. The most effective of these materials is a random basic copolymer of alanine, glutamic acid, lysine and tyrosine, denoted COP 1. The finding that the suppressive polymers show immunological cross-reactivity with the encephalitogenic protein provides a logical basis for the explanation of their suppressive activity in terms of an immunological desensitization mechanism. Our studies suggest that the effectiveness of COP 1 in preventing EAE results from the production of antigen-suppressor T cells, and/or from blocking MBP-specific effector T cells. The results of the clinical trial presented here show demonstrable improvement in the COP 1-treated patients as compared with the placebo subjects, particularly for those patients with less severe MS at the start of the treatment. Thus, although the evidence supporting the antigenic role of MBP in MS is not strong, COP 1, a synthetic polypeptide simulating some of the properties of MBP, appears to be effective in altering the course of MS and is of potential value as a modality for the treatment of this disease.

Animals↗
PubMedDate not supplied

Research on a new type of antiinsulin antibody in a diabetic female patient: the cytotoxic antibody. antiinsulin cytotoxic antibody.

A study was carried out on a diabetic patient showing allergy to insulin, with urticaria and Quincke's edema, apparently owing to sensitization with IgE antibodies. By means of a hyposensitizing treatment her allergy improved due to the building up of IgG protecting antibodies, but at the same time she showed resistance to insulin, probably owing to IgG antibodies as well. This suggest that caution should be exerted before applying hyposensitization with insulin on diabetic patients allergic to the hormone. We were able to describe on the same patient a type II sensitization caused by a cytotoxic antibody against insulin. It was shown that this antibody agglutinates leukocytes which had been previously incubated with insulin and damage occurred when complement was present. Those effects could be especifically inhibited when the antigen (insulin) was added to the medium. The antibody belongs to the IgG group and it acts both in vivo and in vitro. In the case under study, the cytotoxic antibody disappeared as soon as treatment with insulin was discontinued for a year, and reappeared when renewed. It does not seem to occur very frequently, for it was not found in 20 consecutive diabetic patients under insulin treatment.

Aged↗
PubMed1977

[New immunologic perspectives on specific desensitization].

The development of objective techniques for the quantitative evaluation of synthesis and production of IgE in man and experimental animals and the sensitivity of basophils in interaction with allergen has made it possible to initiate studies on desensitization on a scientific and objective basis. Several new mechanisms influencing the regulation of antibody formation, including the production of IgE, have recently been discovered, such as suppressor T lymphocytes and autoanti-idiotypic antibodies. Although present empirical methods used for desensitization therapy provide appreciable results, it is to be expected that the emerging immunological knowledge about regulation of IgE production will markedly influence therapeutic approaches in the foreseeable future.

Antibody Formation↗
PubMed1990

A double-blind study of hyposensitization with an alginate-conjugated extract of Dermatophagoides pteronyssinus (Conjuvac) in patients with perennial rhinitis. II. Immunological aspects.

In a 2-year double-blind placebo controlled study an immunological evaluation was carried out on 33 patients (15 males, 18 females, mean age 29.2 years) with mite-induced perennial rhinitis who were submitted to specific immunotherapy (IT) with an alginate-conjugated extract of D. pteronyssinus. The behaviour of IgE, IgG, IgG1 and IgG4 antibodies specific to D. pteronyssinus and its major allergen Der p1 was characterized by assessment of their changes in serum, and changes in IgG in nasal secretions during the treatment. The placebo-treated patients did not show any significant variation in the levels of specific antibodies, while in the actively treated patients we found: a statistically significant decrease (P less than 0.005) of specific IgE, a statistically significant increase of specific IgG (P less than 0.005), IgG1 (P less than 0.005) and IgG4 (P less than 0.005) in serum and a statistically significant increase (P less than 0.001) of specific IgG in nasal secretions. The IgG response showed an early relative predominance of the IgG1 subclass and a late absolute predominance of IgG4 subclass, that confirmed the model of IgG4 restriction in prolonged allergen stimulation. No correlation was found between immunological and clinical data.

Adjuvants, Immunologic↗
PubMed1989

A circulating suppressive factor of platelet cytotoxic functions after rush immunotherapy in Hymenoptera venom hypersensitivity.

A receptor for the Fc fragment of IgE has been described on human blood platelets. This receptor mediated the IgE-dependent stimulation of platelets by the specific allergen in Hymenoptera venom (HV) hypersensitivity. This platelet reactivity was abolished after rush desensitization. To understand the mechanism of such a down-regulation, we studied the effects of sera recovered from patients treated by HV rush desensitization on platelets of untreated HV sensitive patients. The present data describe the presence of a circulating factor able to suppress, in a dose-dependent manner, platelet stimulation by the specific allergen. This circulating factor was not allergen specific, not depleted by IgE or IgG antibody immunoadsorption, and was found at higher concentrations in the sera of patients receiving monthly high dosages of HV (200 micrograms maintenance dose). The physicochemical characterization showed that this circulating factor had a m.w. of 20,000 to 25,000, an isoelectric point of 4.2, was heat and acid stable, and sensitive to trypsin, but not to neuraminidase. These characteristics were similar to a newly described lymphokine, platelet activity suppressive lymphokine, suggesting the intervention of such a lymphokine in HV rush desensitization.

Bee Venoms↗