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BACKGROUND DNA of human cytomegalovirus (CMV) is frequently detected in plasma of donors with primary CMV infection. It is unknown, however, whether leukoreduced blood products from these donors contain sufficient amounts of infectious virus to cause transfusion-transmitted CMV infections (TT-CMV). STUDY DESIGN AND METHODS During a 14-year period, CMV DNA-positive donations were identified as part of several previously published studies. Additionally, further donors with seroconversion were tested for CMV DNA. The serostatus of patients who had received a CMV DNA-positive blood product was determined out of pretransfusion samples. Later samples were examined for development of CMV antibodies. Patients with a follow-up of less than 140 days were also tested for CMV DNA. RESULTS A total of 221 blood products from CMV DNA-positive donations were transfused to 219 recipients. Pretransfusion samples were available for 179 patients, of whom 62 (34.6%) were seronegative. For 39 seronegative recipients of 40 blood products follow-up samples drawn at least 30 days after transfusion were available. The median duration of follow-up was 287 days (range, 38-3784 days). Thirty-six patients were still CMV seronegative in their last sample. Three patients were CMV seropositive due to passive antibody transfer by plasma rich products from seropositive donors, but CMV DNA negative in all tested samples. CONCLUSION TT-CMV was excluded in all recipients of 40 blood products from CMV DNA-positive donations. This corresponds to a 95% interval of confidence for the risk of TT-CMV of less than 7.4%. Because no patient belonged to a typical at-risk population, the results are only valid for immunocompetent subjects.

DNA of human cytomegalovirus (CMV) is frequently detected in plasma of donors with primary CMV infection. It is unknown, however, whether leukoreduced blood products from these donors contain sufficient amounts of infectious virus to cause transfusion-transmitted CMV infections (TT-CMV).During a 14-year period, CMV DNA-positive donations were identified as part of several previously published studies. Additionally, further donors with seroconversion were tested for CMV DNA. The serostatus of patients who had received a CMV DNA-positive blood product was determined out of pretransfusion samples. Later samples were examined for development of CMV antibodies. Patients with a follow-up of less than 140 days were also tested for CMV DNA.A total of 221 blood products from CMV DNA-positive donations were transfused to 219 recipients. Pretransfusion samples were available for 179 patients, of whom 62 (34.6%) were seronegative. For 39 seronegative recipients of 40 blood products follow-up samples drawn at least 30 days after transfusion were available. The median duration of follow-up was 287 days (range, 38-3784 days). Thirty-six patients were still CMV seronegative in their last sample. Three patients were CMV seropositive due to passive antibody transfer by plasma rich products from seropositive donors, but CMV DNA negative in all tested samples.TT-CMV was excluded in all recipients of 40 blood products from CMV DNA-positive donations. This corresponds to a 95% interval of confidence for the risk of TT-CMV of less than 7.4%. Because no patient belonged to a typical at-risk population, the results are only valid for immunocompetent subjects.

Background Donors with short interdonation intervals (e.g., apheresis donors) have an increased risk of window period donations. The frequency of cytomegalovirus (CMV) window period donations is important information to decide whether selection of seronegative donors might be advantageous for patients at risk for transfusion-transmitted CMV infections (TT-CMV). Study Design and Methods CMV seroconversion in 93 donors with positive results in routine CMV antibody testing within at most 35 days after the last seronegative sample was evaluated by Western blot and/or a second antibody test. In donors with unconfirmed seroconversion, an additional later sample was tested. Concentration of CMV DNA was determined in pre- and postseroconversion samples. Results CMV seroconversion was confirmed in 12 donors (13%). Among these, the last seronegative sample was CMV DNA positive in three donors (25%, below 30 IU/mL). The first seropositive sample was CMV DNA positive in 10 donors (83%, maximum 1600 IU/mL). Both prevalence and median concentration of CMV DNA were higher in the first seropositive sample (p = 0.004 and p = 0.02), with maximum concentrations being reached about 2 weeks after seroconversion. No CMV DNA was detected in samples from donors with unconfirmed seroconversion. Conclusion At least in donors with short interdonation intervals, most suspected CMV seroconversions are due to false-positive results of the screening test. As window period donations are rare and contain less CMV DNA than the first seropositive donation, avoidance of blood products from primarily seropositive donors is especially helpful to avoid TT-CMV if donors with short interdonation intervals are concerned.

BACKGROUND: Capillary hemoglobin (Hb) measurement before admission for whole blood donation is performed in many blood donation services, in spite of several studies reporting many donors with low Hb values being missed by capillary Hb screening. STUDY DESIGN AND METHODS: Predonation capillary and venous Hb levels of 9209 first-time donors presenting for whole blood donation were compared. Hb testing was conducted by photometric determination of finger-stick samples with a photometric method (Donor Checker, HemoCue) and using a hematology analyzer for venous samples. RESULTS: Both capillary and venous Hb measurements were available for 8910 donors (96.8%). The arithmetic mean deviation of the capillary Hb from the venous sample was +1.5 ± 6.8 g/L, and the mean deviation was 5.4 ± 4.5 g/L. In 7865 donors (88%), capillary and venous Hb values differed less than 10 g/L from each other, but in 86 donors (1.0%) the difference was at least 20 g/L, and in 10 donors (0.1%), even 30 g/L or more. In 93.3% of females and 98.7% of males, the categorization as having sufficient or too low Hb for blood donation was concordant between capillary and venous measurements. A total of 34.4% of donors with too low results of capillary Hb screening had sufficient venous Hb levels. Only one donor (0.01%) passed the capillary Hb screening despite venous Hb values below 110 g/L. CONCLUSION: The currently available methods for capillary Hb screening allow reliable determination of predonation Hb values under routine conditions. Additional venous Hb measurements in donors with too low capillary Hb values might reduce the rate of deferred donors by approximately one-third.

BACKGROUND: Screening of blood donations for antibodies against hepatitis B core antigen (anti-HBc) is an accepted method to prevent some transfusion-transmitted hepatitis B virus (HBV) infections. However, anti-HBc testing may result in donor loss due to unspecific results in the currently available anti-HBc tests. Algorithms to distinguish true-positive from false-positive results and for reentry of those donors who tested false anti-HBc positive were evaluated retrospectively. STUDY DESIGN AND METHODS: Samples that tested reactive for anti-HBc by chemiluminescent microparticle immunoassay (CMIA) were investigated for anti-HBc by microparticle immunoassay, for anti-HBs and hepatitis B surface antigen (HBsAg) by CMIA, and for HBV DNA by individual-donor nucleic acid testing. Results were classified true positive, indeterminate, and false positive for anti-HBc. Donors who tested indeterminate and false positive were admitted for reentry if follow-up testing for anti-HBc became negative and no further evidence for an HBV infection was apparent. RESULTS: A total of 554 of 148,000 samples, taken from 30,000 individuals within 3 years tested reactive for anti-HBc by CMIA. Of those, 553 could be further classified: 142 (26%) true positive, 76 (14%) indeterminate, and 335 (60%) false positive. A total of 214 of 411 (52%) samples termed indeterminate or false positive were admitted for reentry and able to provide further donations. In one donor, anti-HBc–positive/HBsAg- and HBV DNA–negative HBV DNA was detectable during follow-up. CONCLUSION: According to our proposed algorithm, 26% of anti-HBc–reactive results tested by CMIA were true positive. Many donors tested indeterminate or false positive can provide future donations if our proposed algorithm for reentry is applied. One donor at risk for transmitting HBV was identified solely by anti-HBc testing.

Background Cytomegalovirus (CMV) DNA is frequently detected in plasma of newly seropositive donors. Selection of leukoreduced blood products from donors with remote CMV infection could avoid transfusion-transmitted CMV infections (TT-CMV) due to primarily infected donors. However, there are no data about the prevalence of reactivations in long-term seropositive donors compared to the incidence of window period donations in seronegative donors. Therefore, the optimal transfusion strategy for at-risk patients is unclear. Study Design and Methods Whole blood samples from 22,904 donations were tested for CMV DNA, and CMV DNA–positive donations were categorized as donations from 1) seronegative donors, 2) newly seropositive donors, and 3) long-term seropositive donors. Results Twenty-one donors were reproducibly CMV DNA–positive (0.09%). Frequency of detection and concentration of CMV DNA in whole blood were comparable for seronegative and long-term seropositive donors. Nonreproducibly positive results for CMV DNA in whole blood were more frequent in long-term seropositive donors (0.16% vs. 0.01%, p

Cytomegalovirus (CMV) DNA is frequently detected in plasma of newly seropositive donors. Selection of leukoreduced blood products from donors with remote CMV infection could avoid transfusion-transmitted CMV infections (TT-CMV) due to primarily infected donors. However, there are no data about the prevalence of reactivations in long-term seropositive donors compared to the incidence of window period donations in seronegative donors. Therefore, the optimal transfusion strategy for at-risk patients is unclear.Whole blood samples from 22,904 donations were tested for CMV DNA, and CMV DNA-positive donations were categorized as donations from 1) seronegative donors, 2) newly seropositive donors, and 3) long-term seropositive donors.Twenty-one donors were reproducibly CMV DNA-positive (0.09%). Frequency of detection and concentration of CMV DNA in whole blood were comparable for seronegative and long-term seropositive donors. Nonreproducibly positive results for CMV DNA in whole blood were more frequent in long-term seropositive donors (0.16% vs. 0.01%, p0.01). Only low concentrations of CMV DNA in plasma were detectable in two seronegative donors and one long-term seropositive donor. Highest concentrations of CMV DNA in both whole blood and plasma, however, were found in newly seropositive donors.Prevalences of window period donations among seronegative donors and reactivations among long-term seropositive donors, as well as the CMV DNA concentration in whole blood and plasma samples from these donors, are comparable. Therefore, blood products from both groups could be used for patients at risk for TT-CMV, while those of newly seropositive donors seem to bear an increased risk.

Donors with short interdonation intervals (e.g., apheresis donors) have an increased risk of window period donations. The frequency of cytomegalovirus (CMV) window period donations is important information to decide whether selection of seronegative donors might be advantageous for patients at risk for transfusion-transmitted CMV infections (TT-CMV).CMV seroconversion in 93 donors with positive results in routine CMV antibody testing within at most 35 days after the last seronegative sample was evaluated by Western blot and/or a second antibody test. In donors with unconfirmed seroconversion, an additional later sample was tested. Concentration of CMV DNA was determined in pre- and postseroconversion samples.CMV seroconversion was confirmed in 12 donors (13%). Among these, the last seronegative sample was CMV DNA positive in three donors (25%, below 30 IU/mL). The first seropositive sample was CMV DNA positive in 10 donors (83%, maximum 1600 IU/mL). Both prevalence and median concentration of CMV DNA were higher in the first seropositive sample (p = 0.004 and p = 0.02), with maximum concentrations being reached about 2 weeks after seroconversion. No CMV DNA was detected in samples from donors with unconfirmed seroconversion.At least in donors with short interdonation intervals, most suspected CMV seroconversions are due to false-positive results of the screening test. As window period donations are rare and contain less CMV DNA than the first seropositive donation, avoidance of blood products from primarily seropositive donors is especially helpful to avoid TT-CMV if donors with short interdonation intervals are concerned.

Capillary hemoglobin (Hb) measurement before admission for whole blood donation is performed in many blood donation services, in spite of several studies reporting many donors with low Hb values being missed by capillary Hb screening.Predonation capillary and venous Hb levels of 9209 first-time donors presenting for whole blood donation were compared. Hb testing was conducted by photometric determination of finger-stick samples with a photometric method (Donor Checker, HemoCue) and using a hematology analyzer for venous samples.Both capillary and venous Hb measurements were available for 8910 donors (96.8%). The arithmetic mean deviation of the capillary Hb from the venous sample was +1.5 ± 6.8 g/L, and the mean deviation was 5.4 ± 4.5 g/L. In 7865 donors (88%), capillary and venous Hb values differed less than 10 g/L from each other, but in 86 donors (1.0%) the difference was at least 20 g/L, and in 10 donors (0.1%), even 30 g/L or more. In 93.3% of females and 98.7% of males, the categorization as having sufficient or too low Hb for blood donation was concordant between capillary and venous measurements. A total of 34.4% of donors with too low results of capillary Hb screening had sufficient venous Hb levels. Only one donor (0.01%) passed the capillary Hb screening despite venous Hb values below 110 g/L.The currently available methods for capillary Hb screening allow reliable determination of predonation Hb values under routine conditions. Additional venous Hb measurements in donors with too low capillary Hb values might reduce the rate of deferred donors by approximately one-third.

Screening of blood donations for antibodies against hepatitis B core antigen (anti-HBc) is an accepted method to prevent some transfusion-transmitted hepatitis B virus (HBV) infections. However, anti-HBc testing may result in donor loss due to unspecific results in the currently available anti-HBc tests. Algorithms to distinguish true-positive from false-positive results and for reentry of those donors who tested false anti-HBc positive were evaluated retrospectively.Samples that tested reactive for anti-HBc by chemiluminescent microparticle immunoassay (CMIA) were investigated for anti-HBc by microparticle immunoassay, for anti-HBs and hepatitis B surface antigen (HBsAg) by CMIA, and for HBV DNA by individual-donor nucleic acid testing. Results were classified true positive, indeterminate, and false positive for anti-HBc. Donors who tested indeterminate and false positive were admitted for reentry if follow-up testing for anti-HBc became negative and no further evidence for an HBV infection was apparent.A total of 554 of 148,000 samples, taken from 30,000 individuals within 3 years tested reactive for anti-HBc by CMIA. Of those, 553 could be further classified: 142 (26%) true positive, 76 (14%) indeterminate, and 335 (60%) false positive. A total of 214 of 411 (52%) samples termed indeterminate or false positive were admitted for reentry and able to provide further donations. In one donor, anti-HBc-positive/HBsAg- and HBV DNA-negative HBV DNA was detectable during follow-up.According to our proposed algorithm, 26% of anti-HBc-reactive results tested by CMIA were true positive. Many donors tested indeterminate or false positive can provide future donations if our proposed algorithm for reentry is applied. One donor at risk for transmitting HBV was identified solely by anti-HBc testing.

BACKGROUND: Human cytomegalovirus (CMV) is considered to latently infect blood cells. Transfusion-transmitted infection (TT-CMV) of immunocompromised patients occurs despite the use of CMV-seronegative or leukoreduced units. STUDY DESIGN AND METHODS: The prevalence of CMV DNA in plasma was investigated in 82 blood donors who had previously been seronegative for CMV and showed anti-CMV immunoglobulin G for the first time, 598 blood donors who were seropositive for at least 1 year, and 150 seronegative blood donors. In a second part of the study, the overall prevalence of CMV DNA in blood donations was assessed based on 31,745 donations. RESULTS: CMV DNA was repeatedly detected in plasma samples of 44 percent of newly seropositive donors (12%-62%, depending on the interval to the last seronegative donation). All steadily seropositive or seronegative donors were negative for the presence of CMV DNA. Detection of CMV DNA in connection with seroconversion was accompanied by significantly increased neopterin, increased alanine aminotransferase, and reduced white blood cell counts, but the sensitivity of these surrogate markers was only 71 percent. The overall prevalence of CMV DNA in blood products due to primary CMV infection of donors was at least 0.13 percent. CONCLUSION: Viremia of newly seropositive donors may be an important reason for the residual risk of TT-CMV despite leukoreduction. Furthermore, transfusion of WBC-reduced blood components from seronegative donors could imply a greater risk of TT-CMV than transfusion of WBC-reduced blood from donors who have been seropositive for at least 1 year, because window-phase donations but no reactivation could be detected in this study.