Ritchard G. Cable

A case-controlled multicenter study of vasovagal reactions in blood donors: influence of sex, age, donation status, weight, blood pressure, and pulse.

BACKGROUND: Vasovagal reactions occur in a small, but significant number of blood donors. These reactions may decrease return donation and disrupt blood collection activities. The purpose of this study was to define the contributory role of sex, age, weight, blood pressure, and pulse in vasovagal reactions with syncope in blood donors.

Iron deficiency in blood donors: analysis of enrollment data from the REDS-II Donor Iron Status Evaluation (RISE) study

BACKGROUND: Regular blood donors are at risk of iron deficiency, but characteristics that predispose to this condition are poorly defined.

Iron deficiency in blood donors: the REDS‐II Donor Iron Status Evaluation (RISE) study

BACKGROUND: Blood donors are at risk of iron deficiency. We evaluated the effects of blood donation intensity on iron and hemoglobin (Hb) in a prospective study.

Pathogen inactivation: making decisions about new technologies Report of a consensus conference

Methods to remove and inactivate pathogens, used extensively in the manufacture of plasma protein fractions, have all but eliminated transmission of infectious agents by these products. 1 Technologies for reducing the risk of infection from single donor blood components have not been embraced as enthusiastically. Several methods have been introduced in Europe. Treatment with solvent/detergent (S/D) or methylene blue have both been applied to plasma components, and psoralen treatment of platelets (PLTs) has begun in several countries. 2-4 Although S/D-treated pooled plasma has been approved for use in the United States and Canada, none of these methods has been adopted for single-donor products in North America. Reasons for slow acceptance include 1) the current safety of the volunteer blood supply; 2) the success of surveillance and development of screening tests to deal with emerging pathogens; 3) the inability of current technologies to inactivate some agents such as spores, prions, and certain small nonencapsulated viruses; 4) concerns regarding remote risks from the residual chemical agents used during the pathogen inactivation (PI) process; 5) absence of any single method to treat whole blood or all components; and 6) the costeffectiveness of these technologies especially compared to strategies to reduce noninfectious risks of transfusion. 5

Iron Stores and Vascular Function in Voluntary Blood Donors

Background—Iron is a pro-oxidant cofactor that may be linked to atherosclerosis progression. Reduction of body iron stores secondary to blood donation has been hypothesized to reduce coronary risk, but retrospective studies have yielded inconsistent findings. We sought to assess the effects of blood donation frequency on body iron stores and physiological and biochemical biomarkers of vascular function associated with atherosclerosis progression. Methods and Results—Forty high-frequency voluntary blood donors (≥8 donations in past 2 years) and 42 low-frequency blood donors (1 to 2 donations in past 2 years) aged 50 to 75 years were randomly selected from American Red Cross of Connecticut blood donor records. Flow-mediated dilation in the brachial artery, serum markers of iron stores, vascular inflammation and oxidative stress, and cardiac risk factors were assessed in all subjects. Serum ferritin was significantly decreased in high-frequency blood donors when compared with low-frequency blood donors (median values 17 versus 52 ng/mL; P<0.001), but hematocrit did not differ between groups. Flow-mediated dilation in the brachial artery was significantly greater in high-frequency donors when compared with low-frequency donors in univariate analysis (5.5±2.6% versus 3.8±1.6%; P=0.0003) and in multivariate analysis adjusting for cardiac risk factors and other potential confounders. Serum biomarkers of vascular inflammation did not differ between groups but 3-nitrotyrosine, a marker of oxidative stress, was decreased in high-frequency donors when compared with low-frequency donors. Conclusions—High-frequency blood donors had evidence of decreased body iron stores, decreased oxidative stress, and enhanced vascular function when compared with low-frequency donors. These findings support a potential link between blood donation and reduced cardiovascular risk that warrants further investigation in prospective outcome studies.

Relationship between tick bites and the seroprevalence of Babesia microti and Anaplasma phagocytophila (previously Ehrlichia sp.) in blood donors

BACKGROUND : Tick‐borne diseases, particularly babesiosis and ehrlichiosis, represent recently emerging infections. Despite an increased recognition of the threat tick‐borne agents pose to blood safety, our understanding of the prevalence and transmissibility of these agents in blood donors is limited.

Seroprevalence of Babesia microti in blood donors from Babesia-endemic areas of the northeastern United States: 2000 through 2007.

BACKGROUND: Current estimates of 70 cases of transfusion‐transmitted Babesia microti, with 12 associated deaths, suggest that Babesia is a growing blood safety concern. The extent of Babesia infections among blood donors has not been well defined. To determine how common exposure to B. microti is among blood donors, a seroprevalence study was undertaken in the American Red Cross Northeast Division.

Demonstrable parasitemia among Connecticut blood donors with antibodies to Babesia microti.

BACKGROUND: Reports of transfusion‐transmitted Babesia microti have risen steadily during the past several years, reflecting a concurrent increase in US cases of human babesiosis. Although several studies have measured B. microti antibodies in blood donors, little is known about associated parasitemia and the inherent risk of transmitting the parasite by transfusion.

Direct assessment of cytomegalovirus transfusion-transmitted risks after universal leukoreduction

BACKGROUND: Cytomegalovirus (CMV) transfusion‐transmitted disease (TTD) remains a clinical concern. Universal leukoreduction has become one of the main strategies for the prevention of CMV‐TTD. Through prospective clinical follow‐up and testing of transfusion recipients (TRs), the risk for CMV‐TTD was studied.

Risk and prevention of transfusion-transmitted babesiosis and other tick-borne diseases.

Purpose of reviewTick-borne diseases have increasingly been recognized in the United States as public health problems. The importance of tick-borne diseases has been accelerated by increases in animal populations, as well as increased human recreation in wooded environments that are conducive to tick bites. Babesiosis, usually caused by the intraerythrocytic parasite, Babesia microti and transmitted by the same tick as Lyme disease, has important transfusion implications. Although Lyme disease has not been reported from blood transfusion, newly identified tick-borne diseases such as ehrlichiosis raise additional questions about the role of the tick in transfusion-transmitted diseases. Recent findingsThe risk of transfusion-transmitted babesiosis is higher than usually appreciated and in endemic areas represents a major threat to the blood supply. Furthermore, the geographic range of B. microti is expanding, other Babesia spp. have been implicated in transfusion transmission in the western United States, and the movement of blood donors and donated blood components may result in the appearance of transfusion babesiosis in areas less familiar with these parasites. Consequently, a higher degree of clinical suspicion will allow early recognition and treatment of this important transfusion complication. SummaryIn endemic areas transfusion-transmitted babesiosis is more prevalent than usually believed. The extension of the geographic range of various Babesia spp. and the movement of donors and blood products around the United States has resulted in the risk extending to non-endemic areas. Clinicians should maintain a high degree of clinical suspicion for transfusion-transmitted babesiosis.