PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Hypersensitivity, Delayed”

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 91 records · Page 5Linked to original sources
PubMed1977

The value of an assessment of erythema and increase in thickness of the skin reaction for a full appreciation of the nature of delayed hypersensitivity in the guinea pig.

Delayed type skin reactions in guinea pigs have been assessed by measuring three parameters: increase in skin thickness, diameter of erythema and intensity of erythema. Some groups of animals were immunized with different protein antigens in Freund's complete adjuvant with or without cyclophosphamide (CY) pretreatment; others received a single high dose of antigen intravenously at the time of immunization. The results emphasize the importance of measuring all three parameters for several days after skin testing. The intensity or erythema was found to be an especially useful parameter for assessing CY-induced modification of delayed hypersensitivity (DH) reactions. The increase in skin thickness, which can be measured objectively, was also valuable as both immediate and DH reactions are characterized by induration. The diameter of erythema could only be measured accurately for a short time after skin testing. Furthermore, the effects of intravenous antigen and CY pretreatment were not reflected by that parameter.

Animals↗
PubMed1983

The influence of age on the induction of delayed hypersensitivity to human gamma globulin.

Delayed hypersensitivity (DH) reactions by chickens to human gamma globulin (HGG) were influenced by age. Chickens 6 to 12 weeks of age exhibited a significantly greater DH reaction than 3-week-old chickens. The injection of HGG 1, 2, or 3 weeks after sensitization did not significantly influence the DH reactions. Our data allow us to reject the hypothesis that there is no significant age difference in the DH response of chickens.

Age Factors↗
PubMed1977

Delayed hypersensitivity and febrile acne conglobata.

Delayed hypersensitivity reactions were investigated in 5 patients with febrile acne conglobata. Each of them had febrile periods, large abscesses and leukocytosis. They reacted negatively to tuberculin 10 TU/ml, to Schick toxin, to oidiomycin, to trichophytin as well as to 25 common contact allergens. DNCB did not induce sensitization in those 4 patients in whom it was carried out. However, the transforamtion of lymphocytes by phytohaemagglutinin (PHA) was normal. Five of 7 control patients with cystic or ordinary acne had positive tuberculin test reactions and 3 of them were sensitized to DNCB.

Acne Vulgaris↗
PubMedDate not supplied

Immediate and delayed hypersensitivity to mite antigens in atopic dermatitis.

Atopic dermatitis (AD) is a common disorder and appears to be on the increase, especially among children. It was thought at first to be a manifestation of immediate hypersensitivity, but it is now known that delayed hypersensitivity also plays an important role. Sensitivity to mite antigens is found in 20% to 60% of patients when immediate hypersensitivity is evaluated by the detection of specific IgE antibodies and prick tests, and in 30% to 50% of patients when delayed hypersensitivity is studied by patch testing. A prospective randomized study was carried out in the pediatric dermatology clinic on a sample of 51 children under 15 years of age. A prevalence of immediate and delayed hypersensitivity to mites, like that described for other populations, was found. It was further found that there was a positive association, not described in the literature, between the younger age groups and delayed hypersensitivity to mite antigens, while the opposite was true for immediate hypersensitivity. We believe that patch tests with airborne allergens, specifically mites, should be part of the protocol for assessing children with AD, particularly in the younger age groups.

Age of Onset↗
PubMed1986

Participation of neutrophils and delayed hypersensitivity in the clearance of experimental cutaneous candidiasis in mice.

Involvement of neutrophils and delayed hypersensitivity in the clearance of Candida albicans infections was investigated with the use of a model of the disease in inbred mice. Experimental infections were produced by rubbing C albicans onto the shaved skin of the flank without the use of occlusive dressings. After a single infection, delayed hypersensitivity to Candida developed in C57BL/6 mice, and the infection cleared more rapidly than in C3H/He mice, in which delayed hypersensitivity did not develop. In both strains, the organisms were associated with neutrophilic microabscesses in the upper epidermis within 1 day of inoculation; by 3 days, the organisms and microabscesses had become relocated to a site just above the skin surface. At this time, the epidermis was intact under the microabscesses and significantly thickened, which indicated that epidermal proliferation had occurred. Delayed hypersensitivity reactions accelerated clearance of the infection, apparently by increasing the rate of removal of the microabscesses and associated organisms from the skin surface. However, delayed hypersensitivity was not an absolute requirement for clearance, because in animals of the C3H/He strain, in which delayed hypersensitivity did not develop during the first infection, the infection was eventually cleared. It is postulated that in these infections an important defense mechanism may be the enhancement, perhaps by the neutrophilic infiltrate, of epidermal proliferation early in the infection such that the infecting organisms are moved to a location above the skin surface from which they can be more easily removed by other processes, including delayed hypersensitivity reactions.

Animals↗
PubMed1992

Modulation of expression of delayed hypersensitivity by mycobacterial antigen 85 fibronectin-binding proteins.

Although demonstration of delayed hypersensitivity to purified protein derivative of tuberculin (PPD) is an important element in the diagnosis of infection with Mycobacterium tuberculosis, many patients with tuberculosis are anergic. Several possible mechanisms for this specific lack of response have been described. We have now uncovered an additional one. T-cell fibronectin (FN), a lymphokine secreted by activated T cells, is closely associated with the initiation of delayed hypersensitivity reactions. Mycobacterial antigen 85 (Ag85) proteins have been shown to bind to plasma FN. The ability of Ag85 to bind to T-cell FN and modulate expression of delayed hypersensitivity was therefore studied. Purified Ag85 proteins from M. tuberculosis, Mycobacterium bovis BCG, or Mycobacterium kansasii bound to T-cell FN, fibroblast FN, and plasma FN in vitro. Purified 65-kDa heat shock protein (hsp65) from M. bovis BCG did not bind to any FN. Ag85, but not hsp65, inhibited the ability of T-cell FN to agglutinate monocytes in vitro in a dose-dependent manner. In vivo, mixtures of PPD or dinitrophenyl-ovalbumin and purified M. tuberculosis or M. bovis BCG Ag85 proteins elicited significantly smaller delayed hypersensitivity inflammatory reactions in sensitized guinea pigs than did PPD or dinitrophenyl-ovalbumin alone. Purified hsp65 did not inhibit expression of delayed hypersensitivity to PPD or dinitrophenyl-ovalbumin. We suggest that Ag85 proteins could inhibit in vivo expression of delayed hypersensitivity during mycobacterial infections because of their interaction with T-cell FN.

Agglutination↗
PubMed1972

Antigen-induced stimulation of glucosamine incorporation by guinea pig peritoneal macrophages in delayed hypersensitivity.

The interaction between sensitized lymphocytes and specific antigen occurring in delayed hypersensitivity causes bystander macrophages to undergo a variety of light-microscopic, ultrastructural, and biochemical changes, which are reflected in alterations in cell movement and intercellular contacts. Since such alterations involve functions of the cell periphery, we postulated that metabolic changes in this polysaccharide-rich zone would accompany the expression of delayed hypersensitivity. We here demonstrate that the incorporation of radioactive glucosamine by peritoneal macrophages into TCA-precipitable, membrane-associated material is regularly enhanced when these are cultured in the presence of specific antigen and nonadherent cells (lymphocytes) primed for delayed hypersensitivity. Lymphocytes from unsensitized animals, or from animals immunized so as to form antibody but not delayed hypersensitivity, do not stimulate such incorporation. Antigen-induced glucosamine incorporation is maximal at 2 or 3 days of culture and is not observed earlier; it may be elicited with as little as 0.1 microg/ml PPD, and affords an exceedingly reproducible and sensitive index of delayed hypersensitivity. Radioautographic studies indicate that nearly all plastic adherent cells (90% macrophages) incorporate glucosamine and that grains are concentrated in the regions of the perinuclear zone and cell membrane. Subcellular fractionation indicates that nearly 30% of counts and the highest specific activity are associated with the membrane-rich microsomal fraction; the microsomal distribution of counts increases in both absolute and relative terms when macrophages are cultured in the presence of specific antigen and sensitized lymphocytes. Taken together, these data indicate that a sizable fraction of incorporated glucosamine is localized to the vicinity of the cell periphery but lack sufficient resolution to determine whether this material is associated with the cell membrane itself or with the extramembranous cell coat. This last possibility is of particular interest since we have previously shown that macrophage cell coat material is lost or altered as a consequence of an interaction between sensitized lymphocytes and specific antigen.

Animals↗
PubMedDate not supplied

Patch tests for diagnosis of delayed hypersensitivity to cephalosporins.

BACKGROUND: Few studies have reported delayed hypersensitivity reactions to systemically administered cephalosporins. The diagnostic procedures and extracts for these reactions are not standardized, and little is known about the extent of cross reactivity among different cephalosporins. CASES REPORT: We report 2 cases of delayed hypersensitivity reactions due to cephalosporins presenting as erythrodermia. Case 1. An 80-year-old man developed generalized pruritus and erythema 2-3 days after starting treatment with cefuroxime. The drug was stopped and antihistamines and corticosteroids were administered. The patient improved 5-6 days later, and mild superficial desquamation was observed. Case 2. A 66-year-old woman experienced similar symptoms 4-5 days after beginning cefazolin. She reported a similar reaction with ceftazidime 8 years previously. METHODS AND RESULTS: Skin prick tests and specific IgE against penicillin G and V, amoxicillin, ampicillin and cephalosporins were negative. Intradermal tests with ceftazidime and cefazolin were positive in case 2 at delayed reading. Patch tests using benzylpenicillin, ampicillin, amoxicillin, several cephalosporins, aztreonam and imipenem were positive to all the cephalosporins tested (at 48 and 96 hours) and were negative to the other betalactams. Controlled administration of amoxicillin, benzylpenicillin, aztreonam and imipenem was well tolerated by both patients. CONCLUSIONS: 1) We report 2 cases of delayed hypersensitivity reactions due to cephalosporins presenting as erythrodermia. 2) Epicutaneous tests were useful for diagnosis. 3) Both patients tested positive to all cephalosporins and negative to other betalactams.

Aged↗
PubMed1982

Delayed hypersensitivity to murine cytomegalovirus and its depression during pregnancy.

A delayed hypersensitivity skin test for murine cytomegalovirus is described, in which ear swelling is measured after injection of heat-killed virus. The response appeared within 4 days of infection, peaked at 8 days, and remained at high levels for at least 100 days. When live virus was inoculated into the ear of previously uninfected mice, a much greater degree of ear swelling was seen, maximal at 7 days, but without growth of virus in the inoculated ear. Mice infected with avirulent (cell culture-passaged) virus gave greater delayed hypersensitivity responses than with those infected with virulent (salivary gland-passaged) virus. One of the strains of mice that is susceptible to murine cytomegalovirus (C57BL) developed greater delayed hypersensitivity responses than did the resistant strain (C3H). The delayed hypersensitivity response of neonatally infected mice was greatly depressed during pregnancy and lactation.

Animals↗