# An antigen-capture assay to screen donated blood for Babesia microti

> **NIH NIH R43** · BIOPEPTIDES, INC. · 2020 · $299,812

## Abstract

PROJECT SUMMARY
In the U.S. ~5 million individuals receive blood transfusions annually. Increasingly, these recipients are being
put at risk of infection with Babesia microti, a tick-transmitted blood-borne parasite that resides in red blood
cells (RBCs) and causes the disease babesiosis. B. microti represents a significant threat to the US blood
supply as it survives blood banking procedures and storage conditions, and can be transmitted via transfusion.
Transfusion transmitted babesiosis (TTB) is responsible for the highest percentage of transfusion-related
infectious fatalities reported to the FDA. There is a critical unmet need for a method that is sensitive and
specific, cost-effective, and high-throughput to screen donated blood for this pathogen. We propose the
development of an EIA-based antigen-capture assay capable of detecting low levels of parasites in blood
donors who are likely unaware that they are infected (e.g., asymptomatic, chronic carriers). We generated a
library of antibodies using B. microti infected mice, and then screened this library to identify antibodies specific
to parasite surface-expressed/secreted proteins. Using these methods, we have identified antibodies to
seven B. microti proteins expressed during mammalian infection. In this study, we will generate an optimized
antigen-capture assay using antibody pairs to one or more parasite secreted/surface target antigens that we
have identified in preliminary studies. In Specific Aim 1, we will optimize capture and reporter antibody pairs
for use in an antigen capture assay for the detection of B. microti, and confirm the specificity and sensitivity
of these capture-reporter antibody pairs. In Specific Aim 2, we will performance our assay using blood
obtained from patients with babesiosis, and identify a finalized antigen-capture assay to proceed to clinical
assay screening with our commercialization partner in a phase II application.

## Key facts

- **NIH application ID:** 9893818
- **Project number:** 5R43AI142877-02
- **Recipient organization:** BIOPEPTIDES, INC.
- **Principal Investigator:** Paul Michael Arnaboldi
- **Activity code:** R43 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $299,812
- **Award type:** 5
- **Project period:** 2019-03-14 → 2021-11-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9893818

## Citation

> US National Institutes of Health, RePORTER application 9893818, An antigen-capture assay to screen donated blood for Babesia microti (5R43AI142877-02). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/9893818. Licensed CC0.

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