JOURNAL CLUB TRANSFUSION

MEDICINE REVIEWS

Christopher Hillyer, Mindy Goldman, and Sunny Dzik, Abstract Editors

Lead levels in blood bank blood. S. Bulleova, S. J. Rothenberg, M. Manalo. Arch Environ Health 56:4312- 4313 2001.

This article was reviewed to show the process necessary to propose additional testing for blood products. The first part of this process includes presenting convincing data showing that the proposed pathogen, substance, or toxin is a risk to recipi- ents. Without substantial data to show this risk, it is not rea- sonable to expect blood bankers to seriously consider test implementation. Further, even if a valid risk to the patient population is proven, the test needs to be cost-effective to support it s implementation. Unfortunately, this report is far from providing the necessary data needed to show that elevated lead levels in donor blood are a valid threat to the recipient population.

Bulleova et al report blood lead levels in 999 units of donated blood drawn in a metropolitan hospital blood bank over a 3-month period in 1999-2000. Although the incidence of lead poisoning has dramatically decreased since the environmental movement to eliminate lead-containing materials from housing and schools, there remain occasional reports of lead poisoning and lead-related deaths in the literature. Thus, the authors of this study wanted to test a large number of donated blood units to determine if any units had lead levels exceeding the recom- mended limits issued by the Centers for Disease Control and Prevention.

The researchers sampled blood from the segments attached to 999 units of donor blood and performed spectrophotometric analysis on the Perkin-Elmer (Shelton, CT) 4100ZL Zeeman atomic absorption spectrometer. Results showed that the mean lead concentration was 1.0/~g/dL, It was found that 2% of the samples contained lead levels that were greater than or equal to 5.0/~g/dL, and 0.2% of the samples tested had lead concentra- tions greater than or equal to 30 /~g/dL.

The investigators note that the lead levels found in their donor population are significantly lower than those reported in 2 other studies. The National' Health and Nutrition Examination Survey conducted from 1991 to 1994 reported the mean blood lead level for the US population to be 2.3/xg/dL. Another study of the Moroccan population reported a mean lead level of 8.7 /xg/dL.

The prevalence of elevated blood lead levels in donated blood reported in this study was low. The authors of the study surmise, however, that because a large volume of blood with the highest reported lead levels exist, transfusion could theoreti- cally lead to lead levels exceeding the Centers for Disease Control recommended safety limits especially if given to an infant or child weighing less than 12 kg. They therefore suggest screening donated blood for lead levels before the administra- tion to infants or small children.

Several issues need t6'be-tal~en"int0 Considerati0n when

examining the data presented in this article. First, it is unusual for infants and children to require a multiple donor, massive transfusion. To arrive at a reasonable risk of an infant or small child succumbing to lead poisoning because of a blood trans- fusion, one would need to multiply the chance of an infant or small child receiving a large or massive transfusion by the chance that they would receive more than one unit of blood with an elevated lead level. This product would represent a miniscule risk and certainly not one that warrants the incurred cost of testing the lead levels of all donated units. Therefore, it is extremely unlikely that an infant Or small child receiving a large enough volume of blood with a significantly elevated lead level could achieve a lead level that would be considered high ac- cording to the Centers for Disease Control criteria. (Above 20 /~g/dL pharmacological therapy is recommended for lead tox- icity) and above 69 ~g/dL, there is a risk of seizures and encephalopathy.) ( C.H. )

The dynamic of hepatitis C virus binding to platelets and 2 mononuclear cell lines. S. Harmaia, C. Li, J.P, AI/ain. Blood 98:2293-2300, 2001,

Viruses such as vaccinia, human immunodeficiency virus, Epstein-Barr virus, influenza virus, cytomegalovirus, dengue 2 virus, and hantavirus are known to bind to human platelets. Harmala et al investigated the interactions of hepatitis C virus (HCV) with platelets and 2 mononuclear cell lines to determine if HCV bound significantly to platelets, Platelets from 30 HCV- seropositive and HCV RNA-positive patients and 5 healthy controls were isolated from the lymphocytes. Separated platelet plasma, buffer from the last wash, and washed platelets were analyzed for HCV RNA, which was detected in "all HCV- infected individuals' plasma and washed platelets but not in their last wash buffer or in any of the controls. It was thus determined that HCV was bound to platelets in chronically infected individuals and may serve as a reservoir of HCV and raises the possibility that transfusion contributes to the almost universal infection of HCV-naive livers after transplantation.

HCV circulates as complexes with lipoproteins or with im- munoglobulins. Plasma from an individual with a medium viral load (1.7 • 105 IU/mL) and one with a high viral load (2.7 • 107 IU/mL) was depleted of immune complexes by passage through a protein G column and RNA was extracted from the plasma to determine viral loads before and after chromatogra- phy. The proportion of free HCV in the original specimens was found to be 3.9% in the medium and 5.2% in the high viral load patients; approximately 95% was therefore bound to IgG. Free HCV bound preferentially to human mononuclear cell lines

Copyright 2002, Elsevier Science (USA). All rights reserved. doi: l O.l O53/tmrv.2002.3 5325

Transfusion Medicine Reviews, Vol 16, No 4 (October), 2002: pp 325-333 325