Clinical Trial Details
— Status: Completed
Administrative data
NCT number |
NCT03049475 |
Other study ID # |
170056 |
Secondary ID |
17-H-0056 |
Status |
Completed |
Phase |
|
First received |
|
Last updated |
|
Start date |
March 13, 2017 |
Est. completion date |
December 9, 2019 |
Study information
Verified date |
June 5, 2024 |
Source |
National Institutes of Health Clinical Center (CC) |
Contact |
n/a |
Is FDA regulated |
No |
Health authority |
|
Study type |
Observational
|
Clinical Trial Summary
Background:
Sickle Cell Disease (SCD) is a blood disorder that occurs mainly in people of African
descent. Researchers want to learn more about the painful attacks and complications
associated with SCD. They want to look for a relationship between SCD and specific changes in
the blood. They want to study the role of genetics, inflammation, and blood clotting factors
in SCD. They will do this with blood samples collected during an acute painful attack and in
between attacks.
Objective:
To learn more about the painful attacks and complications associated with SCD.
Eligibility:
People ages 18-80 with SCD or who are healthy Africans or African Americans without SCD
Design:
- Participants will be screened with medical history and physical exam.
- Healthy participants will have one visit.
- Participants with SCD will have their first visit when they are not having a pain
attack. They will have their next visit during a pain attack. About 3-4 months after
this attack, they will have a final visit.
- Visits will include a physical exam, and blood and urine tests.
- Participants may have their blood samples used for genetic testing for research.
Description:
Episodic pain is the most common acute morbidity and the leading cause of hospitalization in
patients with sickle cell disease. It is caused by microvaso-occlusion induced by sickled red
blood cells, an outcome of the polymerization of deoxygenated hemoglobin S (HbS). Factors
that contribute to the acute sickle pain include the release of cell-free DNA (cfDNA) and
heme that initiate a downstream of events involving inflammation and thrombosis, and
ischemia-reperfusion injury.
Cell-free DNA has been shown to be present in plasma of healthy subjects, but elevated in
diseases and conditions that are characterized by increased cell death through necrosis or
apoptosis. Indeed, we have previously shown that cfDNA in patients with sickle cell disease
(SCD) increased dramatically during acute painful episodes. During acute sickle pain, marked
elevation of plasma hemoglobin has also been observed due to the acute increase in sickled
red blood cells and hemolysis. Both cfDNA and heme (break down product of hemoglobin), act as
damage-associated molecular pattern (DAMP) molecules, initiating endothelial inflammation,
stimulation of neutrophil extracellular trap (NET) formation, leukocyte recruitment, and
microvascular thrombosis.
Although there have been several studies of cytokines and chemokines in steady state and
acute sickle cell disease, there has been no comprehensive study of how the inflammatory
markers correlate with quantitative levels and profile of cfDNA. In this study, we would like
to apply next generation sequencing (NGS) to analyze cfDNA from the plasma of patients with
SCD in steadystate, and during painful crises to derive insights on the origin of tissue
damage. In parallel with the free plasma DNA, we propose to measure markers of hemolysis and
inflammation (cytokines, chemokines), and to investigate if interactions between these
circulating molecules and blood cells (e.g. neutrophils) have the potential to modulate the
progress and severity of the disease. In addition, we would also like to explore if there is
a distinctive cell-free DNA and inflammatory signature in SCD in steady-state and during
acute vaso-occlusive crises.
Overall, this study provides an opportunity to evaluate new biomarkers of sickle cell pain
crisis and to predict disease severity and prognosis. These measures may allow us to better
understand the role of vaso-occlusion, hemolysis, and inflammation-related events and
responses and serve as clinical endpoints in future studies of disease pathogenesis and/or
therapeutic intervention for sickle cell disease.