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. STUDY DESIGN AND METHODS: Transfused units were all leukoreduced and not prospectively screened for CMV. For TRs with negative baseline CMV testing results (CMV total antibody and DNA), all follow-up TR samples were tested for CMV total antibody and DNA, and retained linked donor serum samples were tested for CMV total antibody. In cases when CMV-TTD was suspected, donor sera were also tested for CMV DNA and selected TR samples were tested for CMV immunoglobulin M antibody. Evaluable transfusion was defined as a transfusion with TR sample(s) collected 14 to 180 days posttransfusion. RESULTS: Forty-six TRs were negative for CMV at baseline. There were 1316 evaluable cellular blood transfusions to these TRs. Of 1316 evaluable cellular products, 460 (35%) were positive for CMV total antibody tested using linked donor samples. Three cases of probable CMV-TTD were found; however, there was no definitive proof from donor follow-up that they were transfusion associated. CONCLUSION: Among all 46 baseline seronegative recipients and 1316 evaluable transfusions, the calculated overall CMV-TTD risk was up to 6.5% (95% confidence interval [CI], 1.0%-18.0%) in terms of TRs and up to 0.23% (95% CI, 0.06%-0.62%) in terms of non-CMV-screened leukoreduced cellular products. In summary, after universal leukoreduction, CMV-TTD, while uncommon, may still occur.

A prospective study of multiple donor exposure blood recipients: surveillance value and limitations for hemovigilance.

BACKGROUND: There have been few recent systematic studies of blood recipients for direct evidence of blood safety, especially for emerging pathogens that may pose a threat to the blood supply. STUDY DESIGN AND METHODS: Recipients who would likely require transfusion from multiple donors were recruited and a blood specimen was collected before their first study transfusion and at intervals after their study transfusion(s). Blood samples associated with the units that were transfused to enrolled recipients were also collected. Part of each recipient specimen and selected donor specimens was tested for the targeted blood-borne agents, parvovirus B19 (B19) and Chlamydia pneumoniae (Cp), that were piloted in this study, and the remaining material was kept in a repository. RESULTS: Between April 2004 and December 2006, a total of 120 recipients were recruited with 4047 subsequent donor exposures. On average, each recipient was followed up seven times. Of recipients who were adequately followed up and were initially immunoglobulin G antibody negative, one in 31 and one to two in 49 seroconverted to B19 and Cp after a total of 922 and 1413 evaluable transfusions, respectively. The detection of seroconversion was complicated by passively acquired donor antibodies for these two seroprevalent agents. Negative results for nucleic acids of the agents limited our ability to further clarify the relationship of these seroconversions to transfusion-transmitted infection. CONCLUSION: The risk of transfusion-associated B19 infection appears to be low but no conclusion of transfusion transmission can be made for Cp. The approach piloted through this study offers added value beyond the current hemovigilance strategy in the United States.

Analysis of transfusion reactions associated with prestorage-pooled platelet components.

BACKGROUND: The goal of this study was to assess transfusion reactions arising from prestorage-pooled platelet (PSPP) infusions compared with apheresis single-donor platelets (SDPs) and poststorage-pooled, whole blood-derived random-donor platelets (RDPs). STUDY DESIGN AND METHODS: Over a span of 18 months, transfusion reaction records of patients receiving platelet (PLT) infusions were retrospectively reviewed at two academic, tertiary care hospitals. Chi-square analysis was used for statistical comparisons; significance was a p value of less than 0.05. RESULTS: For the two sites, 10,251 prestorage-leukoreduced PLT products were infused including 4731 PSPPs, 3999 SDPs, and 1521 RDPs. Of the total infusions, 0.91% (93/10,251) were associated with a transfusion reaction. The aggregate transfusion reaction rate was 0.89% (42/4731) for PSPPs, 0.75% (30/3999) for SDPs, and 1.38% (21/1521) for RDPs. There were no significant differences in total reaction rate between PSPPs and the other PLT products (p > 0.05). Allergic transfusion reactions were the most common adverse event for PLT products evaluated (63/10,251; 0.61%) and febrile reactions were second most common (27/10,251; 0.26%). There were 2 suspected cases of sepsis (1 associated with PSPP and 1 associated with RDP; both culture negative) and 1 case of volume overload associated with RDP infusion. There were no significant differences in aggregate allergic or febrile reaction rates among the 93 PLT products evaluated (p > 0.05). No reports of transfusion-related acute lung injury or hemolysis were noted. CONCLUSIONS: No difference in reactions rates was observed among PSPPs and the other PLT products. The transfusion reactions occurring in this population were not dependent on the type of PLT product infused.

Management of blood shortages in a tertiary care academic medical center: the Yale-New Haven Hospital frozen blood reserve.

Threats to national and local blood supplies in America mandate development of an effective blood management system for emergency preparedness and efficient blood inventory management. Seasonal or acute blood shortages could be compounded by the unavoidable distribution inefficiencies of the blood pipeline during an emergency. The Yale-New Haven Hospital (YNHH) Blood Bank has developed a comprehensive emergency blood management plan, which includes maintenance of a tactical, limited frozen blood supply. A computer spreadsheet-based disaster prediction model has been designed to guide the use of the frozen reserve by testing various emergency scenarios. The frozen blood reserve can likely support normal hospital red blood cell (RBC) demands during typical (3-4 days) seasonal shortages, provide a reduced supply for up to 10 days, or meet an unexpected transient increased RBC demand without requiring intensive support from the regional blood center. However, the frozen blood supply is not designed to meet the massive transfusion demand associated with extreme or sustained disasters. Rather, it serves as a short-term bridge-over supply until blood center support can be reestablished. We review the reasons for initiating a blood management plan and describe how YNHH has implemented and sustains a frozen blood reserve as part of a comprehensive disaster management plan. Despite the operational complexity, the benefits of self-sufficiency, the ability to support routine hospital requirements, and the security of having a backup supply justify the expense and difficulty of maintaining a frozen blood reserve.

Reduction of febrile but not allergic reactions to RBCs and platelets after conversion to universal prestorage leukoreduction.

BACKGROUND: Between January 1995 and November 1998, at Yale-New Haven Hospital, 25 percent of RBCs transfused were processed through prestorage or bedside leukoreduction filters, chosen on a per patient basis (selective leukoreduction [SLR]). Between January 1995 and July 1999, 30 percent of platelet concentrates (PCs) were infused through bedside leukoreduction filters. In an attempt to decrease febrile nonhemolytic transfusion reactions (FNHTR), a change was made from SLR to universal prestorage leukoreduction (UPL) for RBCs between November 1998 and December 1999 and for random donor PCs between July 1999 and January 2000. FNHTR and allergic transfusion reactions (ATR) reported from January 1995 through December 2002 were reviewed. STUDY DESIGN AND METHODS: For retrospective observational analysis, blood bank data were available on the number of RBCs and PCs transfused, percent products leukoreduced, and rate of FNHTR and ATR from 1995 through December 2002. After dividing this time period into three phases (SLR, transition, and UPL), these data were evaluated using odds ratio (ORs) and Student's t tests. RESULTS: A total of 145,369 RBCs and 137,982 PCs (29,487 PC pools) transfused between January 1995 and December 2002 were evaluated. For RBCs, the relative FNHTR rate decreased 47.1 percent, from 0.34 percent (SLR) to 0.18 percent (UPL) (p < 0.0001). ATR rates for RBCs showed 0.09 percent for both SLR and UPL groups (p > 0.05, NS). For PCs, the FNHTR relative rate decreased 93.1 percent, from 2.18 percent for SLR to 0.15 percent for UPL (p < 0.0001). Rates for ATR were 0.49 percent (SLR) and 0.35 percent (UPL) (p > 0.05, NS). CONCLUSIONS: A significant decrease in the frequency of posttransfusion FNHTR, but not ATR, for RBCs and PCs followed introduction of 100-percent UPL. The data support the hypothesis that the practice of UPL of RBCs and PCs decreases the frequency of FNHTR and thus improves patient care over the practice of selective leukoreduction.