PROJECT SUMMARY
Basophils play important roles in allergic diseases: their activation is increasingly used for food
allergy diagnosis, and their migration into tissues has been correlated with the onset of
anaphylaxis. However, since basophils are rare, they are less studied and utilized for diagnostics
than other leukocytes, especially in ex vivo microfluidic systems. The overall goal of this project
is to fill this gap by developing enabling microfluidic technologies to better quantify basophil
function, and by using food allergy as a model disease.
Food allergy has reached epidemic proportions and has become a significant source of
healthcare burden. Common in vitro allergy tests lack sufficient accuracy. Oral food challenge,
the gold standard for food allergy assessment, is often not performed as it places the patient at
risk of anaphylaxis. As such, food allergy is often identified only after an adverse reaction that
could be life-threatening. In addition, there is no reliable correlation between the onset of
anaphylaxis and a minimum offending dose of allergen. Metrics to predict anaphylaxis risk in a
patient are essentially non-existent.
Our long-term goal is to address these challenges by developing 1) allergy diagnostic tests
that are accurate, safe, rapid, and accessible, and 2) metrics to better stratify patients at high risk
of anaphylaxis. The overall objective of this pilot grant is to test the hypotheses that: 1) impedance
changes in basophils upon activation, which exposes negatively-charged exteriorized granule
proteoglycans, is an accurate and simple label-free indicator for basophil activation, and 2)
basophil migration and secretion profile correlates with reaction severity. Our approach includes
using whole blood samples from clinically-proven and well-characterized peanut allergic subjects
and healthy controls, and leveraging our interdisciplinary team's expertise in innovative
microfluidic technology and human immunology. We will: (Aim 1) design and validate a label-free
impedance-based basophil activation test using whole blood in the presence of food allergen ex
vivo, and (Aim 2) design and validate a coupled basophil migration and multiplexed secretion
assay ex vivo to determine the correlation with patient history of anaphylaxis.