Apheresis to Obtain Plasma or White Blood Cells for Laboratory Studies

Study Overview
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Brief Summary
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This study will collect blood plasma and white blood cells for laboratory research using a procedure called apheresis. Apheresis is a method of collecting larger quantities of certain blood components than can safely be collected through a simple blood draw. Patients 7 years of age and older with a parasitic infection or condition associated with a parasitic infection (i.e., elevated levels of IgE antibodies or of a type of white cell called eosinophils) who are currently enrolled in a NIH clinical research protocol may be eligible for this study. Relatives of patients and normal healthy volunteers will also be enrolled. Candidates will have a medical history, physical examination and blood tests. Individuals weighing less than 25 kilograms (55 pounds) may not participate. Participants will undergo one of the following two apheresis procedures: Automated pheresis Whole blood is drawn through a needle placed in an arm vein and circulated through a cell separator machine. The plasma (liquid part of the blood) and white cells are extracted, and the red cells are re-infused into the donor through a needle in the other arm. The procedure takes 1 to 2 hours. Manual pheresis Whole blood is drawn through a needle placed in an arm vein and circulated through the cell separator machine. The red blood cells are separated from the rest of the blood and returned to the donor through the same needle. Usually only one needle stick is required and the procedure takes from 30 to 45 minutes. This method is used only in individuals who weigh less than 35 kg (77 pounds).

Detailed Description
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In order to carry out in vitro research procedures on the plasma or leukocyte components of blood, it is often necessary to obtain larger quantities of plasma and/or leukocytes, than can be safely obtained by simple phlebotomy. These components can be easily and safely obtained using apheresis procedures in the Clinical Center Apheresis Unit. This protocol is specifically designed to conform to the requirements of the Apheresis Unit for donors to have apheresis procedures (>7 years of age and greater than or equal to 25kg). Donors must first be admitted to another approved clinical research protocol of the LPD, NIAID before they may have the apheresis procedures described in this protocol. The investigational nature of the studies in which the samples will be used, as well as the risks and benefits of the donation process will be explained to all donors, and a signed informed consent document will be obtained.

Official Title
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Apheresis Procedures to Obtain Plasma or Leukocytes for In Vitro Studies

Conditions
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Leukopheresis, Plasmapheresis

Participation Criteria
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Eligibility Criteria
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INCLUSION CRITERIA: Enrolled on another LPD protocol. Weight greater than or equal to 25 kg Willingness to participate EXCLUSION CRITERIA: Age less than 7 years Weight less than 25 kg Cardiovascular instability Hct less than 30 Inadequate venous access PTT or PT greater than 1.5 normal Pregnancy Women who are actively breastfeeding Other condition which the attending physician or Apheresis Unit staff considers a contraindication to the procedure For Hetastarch procedure Hypertension Evidence of fluid retention

Ages Eligible for Study
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Minimum Age: 8 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| 1<br>Donors first admitted to another approved clinical research protocol of the NIAID before having the apheresis procedures described in this protocol. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| To obtain leukocytes,platelets, and plasma from subjects already enrolled on other NIAID/LPD protocols. | Leukocytes, platelets, and plasma will be collected. | Ongoing as this is a method to collect cells from subjects enrolled on other LPD protocols | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Plasmapheresis, Lymphocytes, Eosinophils, Neutrophils