View clinical trials related to Hypersensitivity, Delayed.
Filter by:Whilst validated tools exist to enable inpatient penicillin assessment and de-labelling, limited evidence is available regarding the safety and efficacy in the outpatient clinic. The ability to deliver point-of-care penicillin allergy testing for a large cohort of patients, without skin testing, will improve patient access to testing and utilization of preferred penicillin antibiotics.
The treatment of allergic contact dermatitis (ACD) can be unsatisfactory, and that other skin diseases such as atopic dermatitis have an increased likelihood of ACD, improved systemic treatments are needed. This research study explores the effectiveness of Baricitinib in treating Delayed-Type Hypersensitivity (allergic) versus Irritant Skin reactions. Subjects for this study need to be healthy males between the ages of 18 and 40. This study will evaluate this by injecting antigens as well as applying them on top of the skin to the forearm then measure the effects of Baricitinib by skin and blood testing.
This study will be conducted in 2 cohorts. In Cohort A, approximately 40 subjects will participate in a single-center, open-label, non-randomized, parallel-group trial to investigate the molecular mechanisms involved in delayed-type hypersensitivity (DTH) to various antigens and assess the most appropriate skin challenge antigen to study the effect of systemic treatments on T cells. Following evaluation of the results in Cohort A, approximately 20 healthy volunteers will be enrolled in Cohort B. This cohort will be a single-center, double-blind, randomized, two-arm, placebo-controlled study to evaluate the effect of corticosteroid treatment on the molecular and cellular phenotype of delayed hypersensitivity response to one if the antigens previously studied in Cohort A.
Ultraviolet (UV) light is part of normal sunlight and has many effects on human skin and health. One of the harmful effects of long-term UV light exposure is that it can cause skin cancer. The mechanism by which UV light causes skin cancer is not entirely understood. One of the ways UV light causes cancer is by modifying DNA molecules in the cells of the skin. Another mechanism involved in cancer formation by UV light is immunosuppression. By this mechanism, UV light inactivates cells of the immune system of the skin. The immune cells are responsible for the detection and destruction of foreign substances and organisms such as bacterias and viruses but they also recognize and destroy cancer cells. UV light is known to prevent cells of the immune system to destroy cancer cells. In laboratory experiments, a medication called denosumab has been shown to diminish the inhibition of ultraviolet-induced suppression of skin immunity. In other words, this medication could block the effect of UV on cells of the immune system and might allow patients taking this drug to be better protected from skin cancer. The objective of this study is to test whether denosumab blocks the immunosuppressive effect of UVB light in healthy subjects. This study is divided into two stages. In the first stage, ten subjects (Cohort 1) will be sensitized to diphenylcyclopropenone (DPCP), a topical sensitizer commonly used for the treatment of alopecia areata and cutaneous warts. By reexposing the subjects to DPCP in incremental doses, dose-response levels of cutaneous hypersensitivity reactions in normal skin will be obtained. This will allow comparison of the normal levels of DPCP-induced cutaneous hypersensitivity (CHS) reaction in non UV-exposed skin (Cohort 1) to the CHS obtained from the two UVB-exposed experimental groups of Cohort 2. In the second stage of the study, 20 subjects (Cohort 2) will be exposed to an immunosuppressive dose of ultraviolet B (UVB) 24 hours prior to DPCP sensitization. This is expected to result in the abolition of CHS upon rechallenge with DPCP. In order to assess whether denosumab can reverse UVB-induced immunosuppression, the subjects will have previously been randomized to receive a single 1mL injection of either 60 mg denosumab (group A; 10 subjects) or 1 mL saline (group B; 10 subjects) two weeks before UVB exposure. CHS reactions elicited by DPCP rechallenge will be compared between the denosumab and saline groups.
This is an exploratory study to develop methodologies for the assessment of T-cell mediated therapies via skin immune challenges studies in healthy volunteers. The study will investigate what is the most appropriate; skin challenge agent, time and methodology to sample and characterise T-cells in the delayed type hypersensitivity (DTH) skin reaction. The skin challenge agents to be used in this study will be the neoantigen Keyhole Limpet Hemocyanin (KLH) and recall antigen Tuberculin Purified Protein Derivative (PPD). Part A of the study will assess an intradermal (ID) KLH challenge in three subjects to assess if the immune response to KLH is initiated by the innate or adaptive immune system. Each subject will receive one ID dose of 0.1 milligram (mg) KLH and will be assessed for a skin inflammatory response. Part B of the study will assess repeat ID challenges 28 days apart; the objective will be to characterise the T-cell response to each challenge and the kinetics of that response. For Cohorts 1A and 1B, 16 subjects will receive an initial subcutaneous (SC) 5 mg dose of KLH. Fifteen days later the subjects will receive 0.1 mg ID KLH dose and the response will then be assessed 48 and 120 hours after the initial challenge. The ID KLH challenge will then be repeated 28 days later and the response will be assessed at 48 hours (Cohort 1A, 8 subjects) and at 120 hours (Cohort 1B, 8 subjects) post challenge. For Cohort 2, a repeat challenge of either 2 tuberculin Unit (TU) or 10 TU ID PPD will be administered 28 days apart, to 8 subjects. The first challenge response will be assessed 48 and 120 hours post challenge. The second challenge will be administered 28 days after the first and will be assessed at the same timepoints. The repeat challenge 28 days later will allow an intra-subject analysis and will determine if a subject can be used as their own control. Part C of the study will assess repeat ID challenges of PPD and PBS; the objective will be to characterise the T-cell response to each challenge and the kinetics of that response. For Cohort 1, 6 subjects will receive a 0.1ml ID dose of PBS and another dose 24 hours later. Each challenge will be assessed 48 hours post challenge. Approximately 2 subjects will have an assessment of their normal skin as a control. For Cohort 2, a repeat challenge of either 2TU or 10TU ID PPD will be administered 28 days apart, to 6 subjects. The first challenge response will be assessed 48 post challenge. The second challenge will be administered 28 days after the 1st and will be assessed at the same timepoint. The repeat challenge 28 days later will allow an intra-subject analysis and will determine if a subject can be used as their own control. The total duration of this study for Part A is 14-18 days plus up to 30 days screening. The total duration of this study for Cohort 1A is 56-60 days plus up to 30 days screening. The total duration of this study for Cohort 1B is 59-63 days plus up to 30 days screening. The total duration of this study for Cohort 2 if 2TU is used is 45-49 days plus up to 30 day screening. The total duration of this study for Cohort 2 if 10TU is used is 48-51 days plus up to 30 days screening. The total duration of this study for Part C Cohort 1 is 15-19 days plus up to 30 day screening. The total duration of this study for Cohort 2 if 2TU is used is 42-46 days plus up to 30 day screening. The total duration of this study for Cohort 2 if 10TU is used is 45-49 days plus up to 30 days screening.
An observational clinical study will be performed in subjects aged 12-60 years old to describe the dynamic changes of humoral immune/cellular immunity after vaccination of influenza vaccine, and to discuss the role of different antibodies against influenza virus infection, and to look for possible factors related to side effects with the vaccine.
BCG vaccination has been found to provide greater protection against TB in the UK than in Malawi. This study compares immune responses in BCG-vaccinated and unvaccinated teenagers and young adults in Malawi and in the UK.
To determine the frequency of delayed-type hypersensitivity (DTH) reactions in HIV-positive patients to two doses of two envelope glycoprotein antigens prepared differently. To determine whether patients who have previously demonstrated a DTH response to intradermal MGStage HIV-1 gp160 IIIB baculovirus (MicroGeneSys) have a reproducible response to a repeat injection of gp160 and whether there is cross-reactivity to intradermal HIV-1 rgp160 IIIB vero cell expressed (Immuno-AG). PER 4/5/95 AMENDMENT: To also determine whether patients who respond to HIV-1 rgp160 IIIB baculovirus (MicroGeneSys) have cross-reactivity to intradermal skin tests of HIV-1 rgp160 MN (Immuno-AG). Previous studies in individuals immunized with gp160 suggest that a skin test response in immunized patients can be used as a surrogate marker for new proliferative and cytotoxic responses induced by vaccination.
To determine the safety of intradermal gp160 in HIV seropositive individuals who are asymptomatic and have a relatively intact immune system. To determine whether there is evidence of a delayed-type hypersensitivity (DTH) response (a "positive" skin test) in these patients, and also the dose of gp160 that elicits a delayed-type hypersensitivity (DTH) response. Early immunity to HIV may play an important role in the long interval between virus infection and the onset of clinical disease. Immune responses have been demonstrated in HIV-infected individuals within weeks to months of infection. Although none of these responses has been shown to be protective, it is possible that boosting anti-HIV immune responses through immunization may slow the progression of HIV infection. DTH responses to HIV-derived recombinant envelope glycoprotein could provide a means of measuring an important immune function in infected patients, and serve as an easily measured surrogate marker of cellular immunity. In addition to eliciting local, cutaneous DTH responses, intradermal inoculation of skin test antigens may be immunogenic, resulting in new antibody production and cellular immune responses. This study allows direct comparison of gp160 administered intradermally with alum-adjuvanted intramuscular preparation with respect to immunogenicity in HIV seropositive patients.