Nevirapine (NVP) is globally effective in combination treatment of HIV. Its current use in first line therapy is limited by severe immune-mediated adverse drug reactions (IM-ADRs) that significantly adversely impact patient outcome and healthcare costs. Distinct clinical phenotypes of NVP IM-ADRs include Stevens-Johnson Syndrome/Toxic epidermal necrolysis (SJS/TEN) and Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS). DRESS is dependent on both CD4+ and CD8+ T cells and is characterized by fever, rash, hepatitis and eosinophilia. SJS/TEN is a human leukocyte antigen (HLA) class I restricted, CD8+ T-cell dependent hypersensitivity syndrome, which presents as a severe blistering skin rash that can lead to extensive and life-threatening epidermal necrosis. SJS/TEN is the severest IM-ADR and is complicated by a 50% age-dependent mortality rate and severe long-term morbidity in survivors. Pure T-cell mediated ADRs are strongly associated with genetic variation in HLA loci which has led to successful preventive genetic screening such as HLA-B*15:02 screening to prevent carbamazepine SJS/TEN. Current information on key risk HLA alleles specifically associated with NVP IM-ADRs across diverse populations in Africa and Asia is lacking. We have recently identified HLA-C*04:01 as a significant class I risk allele in South African HIV+ patients with NVP SJS/TEN. Another key unanswered question central to the mechanism of HLA-associated IM-ADRs is why hypersensitivity generally occurs in only a small proportion of those carrying an HLA-risk allele. We hypothesize that the immunophenotypic characterization and T-cell receptor (TCR) specificities of the drug- specific T cells in NVP IM-ADR patients will help answer this question. To facilitate the study of IM-ADRs, our research group has established global collaborations that have led to accrual of one of the largest international biobanks of PBMCs, blister fluid and skin biopsies from patients with T-cell mediated ADRs.
In Aim 1, I will immunophenotype the specific T cells responsible for NVP SJS/TEN in patients carrying a defined risk allele. I will characterize these NVP-responsive cells based on their cytokine outputs and cell surface and activation markers using enzyme-linked immunospot (ELISpot) assays and flow cytometry respectively.
In Aim 2, I will use ELISpot and flow cytometry to characterize the NVP-responsive T cells implicated in NVP DRESS. Finally in Aim 3, I will use single cell TCR sequencing, a Jurkat TCR reporter assay and droplet digital PCR, to identify and confirm the TCR specificities of the T-cell repertoire in patients with NVP IM-ADRs. Our proposed work will leverage clinical and immunologic approaches to define the immunopathogenesis of two distinct cutaneous NVP IM-ADR phenotypes. It is expected that these approaches will ultimately lead to translational outputs such as a sensitive predictive assay to identify the dominant cross-reactive TCRs in the peripheral blood of patients who are destined to develop NVP IM-ADRs. This research will provide the foundation to study the immunopathogenesis of other IM-ADRs and provide a roadmap for their preclinical prediction and prevention.

Public Health Relevance

Nevirapine (NVP), a drug used globally to treat human immunodeficiency virus (HIV), is associated with severe hypersensitivity reactions in a subset of patients. These immune-mediated adverse drug reactions (IM-ADRs) are a source of major burden to patients, the healthcare system and drug development. This study aims to define the immunopathogenesis of two distinct cutaneous NVP IM-ADR phenotypes with the goal of establishing future predictive tests to identify those at risk for HLA-restricted disease.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Individual Predoctoral NRSA for M.D./Ph.D. Fellowships (ADAMHA) (F30)
Project #
1F30AI131780-01A1
Application #
9407907
Study Section
Special Emphasis Panel (ZRG1-F17-M (20)L)
Program Officer
Gondre-Lewis, Timothy A
Project Start
2017-06-01
Project End
2020-04-30
Budget Start
2017-06-01
Budget End
2018-05-31
Support Year
1
Fiscal Year
2017
Total Cost
$28,247
Indirect Cost
Name
Vanderbilt University Medical Center
Department
Other Health Professions
Type
Schools of Medicine
DUNS #
965717143
City
Nashville
State
TN
Country
United States
Zip Code
37240