Protocol Number: 04-CC-0046

Title:

Citrate Effects and Bone Density Studies in Long-Term Apheresis Donors

Number:

04-CC-0046

Summary:

This study will examine the effects of repeated apheresis procedures on bone density and calcium balance. Apheresis is a procedure for collecting large numbers of a specific blood component, such as white cells (leukapheresis) or platelets (plateletpheresis). For the procedure, whole blood is collected through a needle in an arm vein and is directed through a machine that separates it into its components by spinning. The desired cells are removed and the rest of the blood is returned to the donor, either through the same needle or through a needle in the other arm. A blood thinning medicine called citrate is added to the cell-separating machine. Citrate reduces the ionized calcium levels in the blood, which prevents the blood from clotting. When the blood is returned to the donor, the donor also receives the citrate. This lowers the donor's ionized calcium levels which may irritate nerve and muscle cells, causing tingling around the mouth, hands, and feet during the procedure. The reduced ionized calcium levels result in increased parathyroid hormone levels in the donor, can effect bone calcium stores. In addition, some of the citrate that is returned to the donor is excreted in the urine along with calcium, which causes further loss of calcium from the body. It is not known if the calcium loss during apheresis in people who undergo this procedure repeatedly has any long-term effects on body calcium balance and bone calcium stores. This study will measure bone density and calcium balance in long-term platelet and white cell donors and compare the findings with those of whole blood donors, who do not receive citrate.

Healthy people between 18 and 80 years of age who weigh between 110 and 300 pounds, do not have a metal prosthesis, and are not pregnant may be eligible for this study. Participants undergo the following procedures:

Whole blood donors

- Blood sample collection 2 weeks before blood donation.

- I removed undergo standard whole blood donation

-Urine sample collection.

- DEXA scan to assess bone density by measuring bone calcium stores. For this procedure, the subject lies still on a table while the spine, hip, and whole body are scanned using a small amount of radiation. The forearm is also scanned while the subject is seated. The scan may be repeated after 2 years.

Plateletpheresis and leukapheresis donors

- Standard platelet or white cell donation.

- Blood sample collections immediately prior to and after donation, and on the first, fourth, and fourteenth days after donation.

- Urine sample collections at the beginning and at the end of the apheresis procedure and on the first, fourth, and fourteenth days after the donation.

- DEXA scan at the beginning of the study (no earlier than 2 weeks after their latest apheresis donation). The scan may be repeated after 2 years.

- Some apheresis donors may be asked to have a second procedure in which they take calcium according to standard guidelines for plateletpheresis and leukapheresis. During the second procedure, platelet donors will take oral calcium tablets before starting plateletpheresis. White cell donors will receive calcium intravenously (through a vein) during the second leukapheresis. For this second procedure, the donors provide additional blood and urine samples as described above.

Sponsoring Institute:

Warren G. Magnuson Clinical Center (CC)

Recruitment Detail

Type: Active Accrual Of New Subjects

Gender: Male & Female

Referral Letter Required: Yes

Population Exclusion(s): None

Eligibility Criteria:

INCLUSION CRITERIA:

Healthy donors who meet all American Association of Blood Banks, Food and Drug Administration and NIH DTM criteria for allogeneic or research blood donation and who have donated blood or apheresis components greater than 50 times in a 10 year period.

Age greater than or equal to 18 years and less than or equal to 80 years.

Weight greater than or equal to 50 kg and less than 135 kg.

Able to give informed consent

Able to donate as early as 08:00 in the morning (apheresis donors only).

EXCLUSION CRITERIA:

Pregnancy

Metal prosthesis in place

Any prior radiologic contrast administration within preceding one week (includes CT contrast, MRI contrast, intravenous pyelogram, barium swallow or fluoroscopy)

Weight less less than 50 Kg (minimum weight to donate platelets, leukocytes, whole blood)

Weight greater than135 Kg (maximum weight for DEXA Scan)

More than 2 lifetime apheresis donations for whole blood donors (most recent apheresis must be at least one month prior to this study).

Special Instructions: Currently Not Provided

Keywords:

Plateletpheresis

Lymphocytapheresis

Apheresis

Citrate

Bone Density

Recruitment Keywords:

Healthy Volunteer

HV

Conditions:

Blood Component Removal

Investigational Drug(s):

None

Investigational Device(s):

None

Contacts:

Patient Recruitment and Public Liaison Office
Building 61
10 Cloister Court
Bethesda, Maryland 20892-4754
Toll Free: 1-800-411-1222
TTY: 301-594-9774 (local),1-866-411-1010 (toll free)
Fax: 301-480-9793

Electronic Mail:prpl@mail.cc.nih.gov

Citations:

Hester JP, McCullough J, Mishler JM, Szymanski IO. Related Articles, Links No abstract Dosage regimens for citrate anticoagulants. J Clin Apheresis. 1983;1(3):149-57. No abstract available. PMID: 6546053

Hester JP, Ayyar R. Related Articles, Links No abstract Anticoagulation and electrolytes. J Clin Apheresis. 1984;2(1):41-51. No abstract available. PMID: 6536658

Dzik WH, Kirkley SA. Related Articles, Links No abstract Citrate toxicity during massive blood transfusion. Transfus Med Rev. 1988 Jun;2(2):76-94. Review. No abstract available.

PMID: 2980082

• Questions about participating in a study, please contact the Patient Recruitment and Public Liaison Office, CC.
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