Heterotaxy Syndrome Clinical Trial
Official title:
Defining Immunodeficiency in Heterotaxy Syndrome: Pilot Study Data
The investigators aim with this study is to investigate the mechanisms of immune deficiency
in patients with heterotaxy syndrome through the use of novel biomarkers and a prospective
questionnaire survey documenting the burden of infectious sequelae following enrollment. It
is known that patients with under-active spleens (functional asplenia or hyposplenia)
secondary to other (non-cardiac) conditions such as Sickle Cell Disease or Inflammatory
Bowel Disease have a characteristic paucity of a B cell sub-class known as IgM memory B
cell. This specific sub-class of B cell normally matures in the spleen and in those with an
improperly functioning spleen a significant deficiency of this B cell class is seen on flow
cytometry.
Similarly, these same patients are noted to have increased amounts of 'junk' DNA / nuclear
remnant in their red cells. This is seen on microscopy as a dark particle inside the red
cell and is termed a Howell Jolly Body (normally less than 2% of red cells have these dark
particles present). Part of a functioning spleen's normal task is to rid the blood of red
cells that contain nuclear remnants and an under-active spleen gets behind on this task with
a build-up of Howell Jolly Bodies in red cells present in the bloodstream. Flow cytometry
can very quickly and accurately quantify Howell Jolly Bodies as well as IgM memory B cells
from a small (~1.5cc) sample of blood. Normal IgM memory B cell ranges are known for healthy
children from infancy onwards allowing interpretation of results against normative data
ranges.
The investigators aim to enroll 10 patients in this pilot study who have a diagnosis of
heterotaxy syndrome (both asplenia and polysplenia) and to prospectively follow them after
obtaining the initial biomarker sample. The family will be contacted once every two weeks
for a period of 12 weeks and asked a series of simple questions taking approximately 5
minutes on any recent infectious sequelae or symptoms. The questions will elucidate history
of minor illness such as low-grade fever or cough to more significant events such as
admission for in-patient antibiotic therapy of bacterial sepsis. Ultimately, with this pilot
study, the investigators hope to obtain sufficient data to support funding applications for
a larger, multi-center trial that will allow us to develop biomarker thresholds for future
risk of sepsis.
n/a
Observational Model: Cohort, Time Perspective: Prospective
| Status | Clinical Trial | Phase | |
|---|---|---|---|
| Completed |
NCT01591928 -
Heterotaxy Syndrome and Intestinal Rotation Abnormalities - A Prospective Study
|
||
| Recruiting |
NCT02432079 -
Molecular Genetics of Heterotaxy and Related Congenital Heart Defects
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