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NIAID HIV and Emerging Infectious Diseases Program

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P-MOBILE Study

Study name

Hematopoietic Stem Cell Mobilization in Idiopathic CD4 Lymphocytopenia Patients and Healthy Controls for the Study of T Cell Maturation and Trafficking in Murine Models

Study number

14-I-0020

Goal of Study

The purpose of this study is to collect blood from people with "idiopathic CD4 lymphocytopenia", or ICL, and healthy volunteers. Specifically, we are interested in studying special blood cells called stem cells. Stem cells form the blood in our bodies by producing billions of new blood cells each day. Many of these blood cells help our bodies to fight infection including one group of immune cells called lymphocytes.

People with ICL have a low number of lymphocytes and are at risk of frequent infections that can be severe. We will use the blood collected in this study to conduct research in mice and in the laboratory that may provide new information about what causes ICL and what might be done to treat it. Volunteers will be compensated.

So that we can collect enough stem cells to study, participants in this study will be given injections of two medications, G-CSF (Neupogen®) and plerixafor (Mozobil®) before donating their blood (stem cells). These medications help to "mobilize" or move stem cells from the bone marrow into the blood stream. These medications are approved by the U.S. Food and Drug Administration (FDA) and are often given to cancer patients before a treatment called stem cell transplantation, commonly referred to as bone marrow transplant. The medications have been used to mobilize stem cells in healthy volunteers but not in ICL patients.

Study regimen

About 20 people (ages 18-65) will take part in this study. You are being asked to be in this study because you either have ICL or are a healthy volunteer. After screening, your total study participation time is approximately 2 weeks. Study procedures include physical exam; blood draws; urinalysis; sonogram of your spleen; G-CSF (Neupogen®) and plerixafor (Mozobil®) injections; stem cell donation by leukapheresis; and genetic testing.

Genetic testing

For this study, we are asking you to allow us to do genetic testing on large portions of your DNA. We will compare DNA from patients with ICL to DNA from healthy volunteers to look for gene differences that may cause disease. Your genetic material can be obtained from blood, a saliva sample, or from a cheek swab which takes skin cells from the inside of your cheek. DNA can also be obtained from your skin or hair follicles. For the purposes of this study, we will use samples of stored blood that we will collect or have already collected as part of the P-mobile study.

Researchers use many methods to look for differences in genes, but two of the methods that are currently in use are whole genome sequencing and whole exome sequencing. Both methods allow us to look at a wide range of an individual's genetic material to find changes within a gene that may affect a person's health. Using these powerful testing methods means we would look for changes in all or most of your genes that could cause or contribute to ICL. Genetic testing under this protocol will not be limited to these two methods of testing and may include other methods that are available in the future.

Whole genome sequencing is the broadest method because it involves looking at all of your DNA. This includes areas of the DNA that code, or instruct the body how to function, as well as areas of DNA whose biological function is unknown . The results of whole genome sequencing are a form of code representing each of your 3 billion nucleotide pairs.

Whole exome sequencing is a more selective method in which we look only at "exons", which are the parts of your DNA that direct the body to make proteins for cell function and development. The exons are where most of your genes are located. About 85% of the genes known to cause diseases are located within the exons. Whole exome sequencing is an efficient method DNA testing, but it could miss a gene that is causing a problem.

Eligibility criteria

ICL patients:

  • You are 18-65 years old
  • You have a documented history of Idiopathic CD4 Lymphocytopenia (ICL) with a t-cell count of <300 twice within a six week period
  • You are HIV-negative
  • You have a primary care provider
  • You do not have any difficulty having blood drawn
  • You do not have hepatitis B or C
  • You have never had an allergic reaction to aspirin or ibuprofen
  • If female, you are not currently breast feeding, pregnant, or plan to get pregnant in the near future
  • You are able to stay as an inpatient at NIH for at least 24 hours
  • You agree to have genetic testing

For healthy volunteers:

  • You are 18-65 years old
  • You are HIV-negative
  • You have a primary care provider
  • You do not have any difficulty having blood drawn
  • You have never had an allergic reaction to aspirin or ibuprofen
  • You weigh at least 110 pounds, but less than 350 pounds
  • You do not have any medical conditions or illnesses
  • If female, you are not currently breast feeding, pregnant, or plan to get pregnant in the near future
  • You are able to stay as an inpatient at NIH for at least 24 hours
  • You agree to have genetic testing
  • You live in the DC Metro area, and you can travel Bethesda, MD? (Healthy volunteers must be in DC area; ICL patients do not have to be from DC area only.)​

Last Updated December 20, 2013