Clinical Trial: Defining Immunodeficiency in Heterotaxy Syndrome: Pilot Study Data

Study Status: Completed
Recruit Status: Completed
Study Type: Observational

Official Title: Defining Immunodeficiency in Heterotaxy Syndrome: Pilot Study Data

Brief Summary:

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

Detailed Summary:
Sponsor: Boston Children’s Hospital

Current Primary Outcome:

  • Howell Jolly Body quantification [ Time Frame: At time of recruitment ]
  • IgM Memory B Cell quantification [ Time Frame: At time of recruitment ]


Original Primary Outcome:

  • Howell-Jowell Body quantification [ Time Frame: At time of recruitment ]
  • IgM Memory B Cell quantification [ Time Frame: At time of recruitment ]


Current Secondary Outcome: Results of phone questionnaire of parents documenting infectious symptoms and sequelae [ Time Frame: Once every 2 weeks for 12 weeks following enrollment ]

Original Secondary Outcome: Same as current

Information By: Boston Children’s Hospital

Dates:
Date Received: August 23, 2013
Date Started: August 2013
Date Completion:
Last Updated: June 26, 2014
Last Verified: June 2014