# Extracellular Vesicles as Biomarkers of Immediate Hypersensitivity Reactions

> **NIH NIH R21** · JOHNS HOPKINS UNIVERSITY · 2024 · $163,750

## Abstract

PROJECT SUMMARY
Anaphylaxis is a systemic, potentially fatal, immediate hypersensitivity reaction (IHR) that can be triggered by
foods, drugs, vaccines, singing insect venom, exercise, or even idiopathically. Accurate diagnosis is essential
in both the acute setting, when medical intervention can be life-saving, and during subsequent outpatient
evaluation, when management depends on confirming the diagnosis and identifying the triggering substance.
The diagnosis of anaphylaxis is based on symptoms, which is problematic due to the wide variability of clinical
presentations and substantial overlap of allergic symptoms with other disease states. These diagnostic
complexities and lack of reliable biomarkers for IHRs contribute to the misdiagnosis and subsequent
mismanagement of food and drug allergies. Current known biomarkers for systemic allergic reactions are lacking
in that none are both sensitive and specific. Therefore, there is a sizable unmet need to discover novel
biomarkers of IHRs that are both highly-sensitive and specific for all contexts, mechanisms, and severities of
anaphylactic reactions. This proposal’s central objective is to characterize and quantify circulating extracellular
vesicles (EVs) as novel biomarkers of acute IHRs using patient samples obtained from ongoing clinical trials.
Aim 1 will characterize the quantities, surface marker expression, and contents of plasma cell-specific EVs in
adults after acute IgE-mediated IHRs to foods, and compare findings to patients’ baseline. Aim 2 will similarly
characterize EVs in adults after acute non-IgE-mediated IHRs to drugs. Aim 3 will create a biobank of patient
samples for analysis of alternative biomarkers using cutting edge technologies. This highly feasible and valuable
clinical research project is expected to identify novel biomarkers that will aid in the accurate diagnosis of
anaphylaxis as well as provide new insight into the mechanisms of certain drug IHRs. This application is in
response to the program announcement for Exploratory and Developmental Research Grant Program for NIAID
K-award Recipients. This award will provide crucial support and resources for the PI as she transitions to
research independence.

## Key facts

- **NIH application ID:** 10864085
- **Project number:** 1R21AI182531-01
- **Recipient organization:** JOHNS HOPKINS UNIVERSITY
- **Principal Investigator:** Melanie C. Dispenza
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $163,750
- **Award type:** 1
- **Project period:** 2024-06-13 → 2026-04-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10864085

## Citation

> US National Institutes of Health, RePORTER application 10864085, Extracellular Vesicles as Biomarkers of Immediate Hypersensitivity Reactions (1R21AI182531-01). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/10864085. Licensed CC0.

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