Current Status of Irradiated Blood Components and Blood Irradiators in Korean Medical Institutes / 대한수혈학회지

BACKGROUND: Gamma or X-ray irradiation of blood components is used to prevent transfusion associated graft-versus-host disease (TA-GVHD). In this study, we assessed the current status of irradiated blood components and blood irradiators in Korean medical institutes. METHODS: We surveyed 306 medical institutes in Korea by a questionnaire, between August 2015 and October 2015. Institutions were asked to answer 9~16 questions, including whether they had facilities for irradiation of blood, type of irradiators used, dose of irradiation used, and if they did not have irradiation facilities, they were asked whether their blood components were irradiated. RESULTS: One-hundred and ninety-seven (64.4%) out of 306 questionnaires were returned and analyzed: 96 institutions provide irradiated blood, and 101 institutions do not use irradiated blood components. Forty-eight institutions have on site facilities with gamma blood irradiator for the irradiation of blood components and uses a dose of 20 to 50 Gy. Of the 48 institutions without facilities that use irradiated blood components, 38 (79.2%) have their blood components by referral to Korean Red Cross Blood Centers and 9 (18.8%) refer to other medical institutes for their irradiation needs. The survey showed that there is lot of regional variation in the supply and demand of irradiated blood components in Korea. CONCLUSION: Our survey does suggest that the establishment of the supply system for irradiated blood component by nation-wide blood establishments may provide national nuclear safety and stability of irradiated blood supply. It may also alleviate some regional disparity for the transfusion service of irradiated blood in Korea.

Unrelated Hematopoietic Stem Cell Donor Recruitment of the Korean Red Cross: 20 Years Experience / 대한수혈학회지

BACKGROUND: The National unrelated hematopoietic stem cell (HSC) donor program started in 1994. The Korean Red Cross (KRC) has participated in this program from the start as a recruiting organization. Results of 20 years of donor recruitment were analyzed to make suggestions to manage potential donors more effectively and improve retention rate. METHODS: Statistics on registration, deregistration, and donation of potential HSC donors registered in the Korean Network for Organ Sharing (KONOS) registry from 1994 to 2013 were analyzed. For donors recruited by the KRC, gender and age distribution, and reasons for self-withdrawal were also analyzed. RESULTS: As of 2013, a total of 265,307 potential HSC donors have been registered in the KONOS registry, among which 38.8% have been recruited by the KRC. Rate of self-withdrawal from the registry was lower for the KRC than the mean of all recruiting organizations (15.9% vs 21.8%). Reasons for withdrawal were objections by family members (34.9%), medical conditions (28.8%), change of donors' mind (21.7%), and other personal reasons (14.6%). The overall retention rate during the 20 year period for KRC was 63.7% which was higher than that of KONOS (58.1%). CONCLUSION: The lower self-withdrawal rate and higher retention rate of donors recruited by the KRC are the result of continuous education of donors to maintain their willingness to donate not only during recruitment but also after registration. This study will help to improve the retention rate and manage registered donors more effectively.

Survey on the Usage of Leukocyte Reduced and Irradiated Blood Components in Korea (2007~2013) / 대한수혈학회지

BACKGROUND: Leukocyte reduced (LR) and irradiated (IR) blood components are used to prevent immunological transfusion-related adverse reactions. However, so far, reports on the usage of LR or IR blood components in Korea are scarce. METHODS: Data from January, 2007 to December, 2013 provided by the Health Insurance Review and Assessment Service of Korea were analyzed. Disease categories of the patients were classified according to the Korean Standard Classification of Disease. RESULTS: In 2013, 26.7% of total transfused blood components were leukocyte reduced and an increase of 5.3% compared to 2007. The proportion of IR components increased from 21.4% in 2007 to 27.9% in 2013. The percentage of LR (IR) blood components for RBCs, platelets, and SDPs was 15.4% (14.7%), 35.1% (38.8%), and 75.2% (80.1%), respectively, in 2013. In particular, the percentage of IR FFPs units increased gradually over the years, from 11.2% in 2007 to 22.7% in 2013. LR and IR components were used mainly in hemato-oncology patients but the proportion showed a downward trend. Due to aging of the society, transfusion of LR and IR components has inclined trends in the 70's or more. CONCLUSION: Although the transfusion rate of both LR and IR blood component is increasing, it is still remarkably lower than that in developed countries. Therefore, LR and IR blood components should be used more extensively. For this, reimbursement criteria for National Health Insurance for these blood components should be extended and the fee schedule for LR and IR blood components should be adjusted to reflect clinical practice and patient need.

Korean Red Cross HLA-Matched Platelet Donor Registry / 대한수혈학회지

BACKGROUND: Transfusion of HLA-matched platelets is required when development of platelet refractoriness occurs after repeated platelet transfusion. This study was conducted to establish a HLA-matched platelet donor registry to supply matched platelets to patients who develop platelet refractoriness. METHODS: HLA-matched platelet donors were recruited among plateletpheresis donors. HLA-A and HLA-B antigen types of recruited donors were tested using a polymerase chain reaction-sequence specific oligonucleotide probe method. RESULTS: A total of 1,029 plateletpheresis donors were recruited. HLA-A and HLA-B antigen frequencies of recruited donors were similar to those of previously reported HLA antigen frequencies of Koreans. During the study period, a patient with platelet refractoriness recovered after receiving six units of HLA-matched platelets. CONCLUSION: During this study 1,029 donors were registered as HLA-matched platelet donors and a patient with platelet refractoriness received HLA-matched platelets using this registry. Supply of HLA-matched platelets will be facilitated by continuous expansion of the number of registered HLA-matched platelet donors, development of a program for management and searching for HLA-matched donors, and establishment of a request-supply system between hospitals and the Korean Red Cross through further studies.

Evaluation of Point-of-Care Testing Devices for Pre-donation Alanine Aminotransferase Test / 대한수혈학회지

BACKGROUND: In Korea, since 1990, in an effort to reduce the transmission of non-A, non-B hepatitis, all blood donations with alanine aminotransferase (ALT) levels above 65 IU/L are discarded. In 2012, 64.8% of the disposed blood units at the Korean Red Cross blood centers were due to high ALT levels. Pre-donation ALT testing might prevent unnecessary blood donation and save related expenses. We evaluated performance of point-of-care test (POCT) devices for pre-donation ALT screening. METHODS: ALT levels by four ALT POCT devices (Mission C100, Acon; Reflotron Plus, Roche; Labgeo PT10, Samsung; and FDC NX500, Fujifilm) were compared with venous blood results using laboratory chemistry analyzers (AU series, Beckman Coulter Inc.). Intraclass correlation coefficients (ICCs), sensitivity (ability to detect ALT > or =65 IU/L), and specificity (ability to detect <65 IU/L) for each method were calculated. RESULTS: Compared with the laboratory analyzers, the ICCs of ALT measurements by Mission C-100, Reflotron Plus, Labgeo PT10, and FDC NX500 were 0.96 (95% confidence interval (CI): 0.95~0.97), 0.99 (95% CI: 0.99~0.99), 0.98 (95% CI: 0.98~0.98), and 0.94 (95% CI: 0.91~0.96), respectively. The sensitivity was 80.95% for Mission C-100, 83.33% for Reflotron Plus, 78.57% for Labgeo PT10, and 97.62% for FDC NX500. The specificity was 99.13% for Mission C-100, 100.00% for Reflotron Plus, 99.78% for Labgeo PT10, and 98.26% for FDC NX500. CONCLUSION: The ALT POCT devices showed almost perfect agreement with the laboratory analyzers and could be useful for pre-donation ALT screening. However, before implementing ALT POCT devices, cost-effectiveness analyses should be performed.

Influence of Pathogen Inactivation on the Quality of Platelet Rich Plasma Derived Platelets / 대한수혈학회지

BACKGROUND: Pathogen inactivation (PI) is a proactive approach to overcome the limitations of the current testing system and donor questionnaires. Effect of PI on non-leukoreduced platelet rich plasma derived platelets (PRP-PLTs) suspended in plasma has not yet been evaluated. This study was conducted in order to evaluate the effect of PI on the quality of non-leukoreduced PRP-PLTs suspended in plasma. METHODS: PRP-PLTs treated with the Mirasol PRT System and the Intercept Blood System were tested for PLT count, blood gas, PLT activation, and apoptosis on days 3, 5, and 7 of storage. RESULTS: PLT number showed a decrease after PI. No difference in pH was observed until day 5. At day 7, PLTs treated with Mirasol had a lower pH value (6.5), however, it satisfied the quality control criteria. PLTs treated with Mirasol had a lower pO2 compared to pre-inactivation PLTs. pO2 during storage differed significantly between the two PI groups. pCO2 showed a decrease after inactivation and both groups showed a significant difference, compared with the control. PLTs treated with Mirasol had increased P-selectin expression after inactivation; however, difference of P-selectin during storage was not significant compared to the control. P-selectin of PLTs treated with Intercept was significantly different compared to those treated with Mirasol and control. Annexin V showed an increase after inactivation in Mirasol treated PLTs and difference during storage was significant compared to control and Intercept. CONCLUSION: As both PI systems showed satisfactory pH values, the criteria showing a high correlation with in vivo PLT viability and generally applied to monitor quality of PLTs, quality of PRP-PLTs after PI appears not to be negatively affected.

Evaluation of RF300 for Leukoreduction of Red Blood Cells / 대한수혈학회지

BACKGROUND: Use of universal leukoreduction for prevention of leukocyte associated transfusion reactions is common practice in many countries. This study was conducted in order to evaluate the performance of a newly developed leukoreduction filter for red blood cells (RBCs), the RF300 (Kolon Industries, Inc, Gumi, Korea). METHODS: Filtration time, RBC recovery, residual leukocyte count, and leukocyte removal rate were evaluated. To assess the quality of RBCs after filtration, percent hemolysis was monitored for a period of 21 days. Performance of the RF300 (N=78) was compared with that of the Bio-R O2 plus (Fresenius, Hamburg, Germany), the Pall Purecell RC (Pall Co., Washington, USA), and the Sepacell R-500N (Asahi, Tokyo, Japan). RESULTS: The shortest filtration time was observed using the RF300 (P<0.05). Using the RF300, recovery of RBC was 96.5%, which was higher than that of two filters (P<0.05). Mean residual leukocyte count was 0.26x10(6)/unit, with a leukocyte removal rate of 3 log. Using the RF300, mean percent hemolysis was 0.32% at day 21, which was comparable with that of two filters, but lower than that of one filter (P<0.05). CONCLUSION: The RF300 meets all established quality requirements for conduct of safe and effective leukoreduction of RBCs.

Development and Preliminary Evaluation of a Leukocyte Removal Aptamer Filter / 대한수혈학회지

BACKGROUND: Leukocyte reduction filters are widely used to prevent transfusion reactions caused by leukocytes in blood components. Commercial filters are not sufficient for removal of leukocytes for prevention of transfusion associated graft-versus-host disease; therefore, irradiation of blood components was performed using expensive equipment. Techniques using an aptamer substituted for antibody have been developed and are available in clinical areas. The purpose of this study is to develop the aptamer filter system and to evaluate its efficiency and the possibility of its clinical application. METHODS: Aptamers targeted to CD45 were selected by the Postech Aptamer Initiative. The aptamer filter in which aptamers attached to beads were bound to leukocytes and removed by magnetic field was developed. Filtration of 14 units of leukoreduction-red blood provided by Korean Red Cross Blood Services was performed using aptamer filters. Leukocyte removal rate and red cell recovery rate were evaluated and bacterial culture was performed. RESULTS: After filtration using the aptamer filters, 45.6% of leukocytes were additionally removed and the red cell recovery rate was 92.8%. No growth in the bacterial culture was observed. CONCLUSION: In order to apply the cell depletion technique utilizing an aptamer to blood filter system, we developed and evaluated the aptamer filter system. Through improvement of the binding efficiency of the aptamer and the filtering process, and application of the various aptamers for other different cells, we suggest that this technique can be applied in the clinical area, such as a substitution for the irradiation process for TAGVHD prevention.

Analysis of the Coagulation Factors of Donated Plasma for Effective Utilization / 대한수혈학회지

BACKGROUND: The aim of present study was to assess the effect of different freezing time after phlebotomy on the activity of coagulation factors in frozen plasma and to evaluate which source plasma for clotting factor fractionation is appropriate for use. METHODS: Blood plasma units rejected due to a high level of ALT were divided into four groups depending on freezing time after phlebotomy, and each unit of the four groups was assayed for six different clotting factors and blood type. SAS 9.2 was used for statistical analysis of data. RESULTS: A decrease was observed in the activities of FVIII of the plasmas, in the following order: PL-A>FFP>FP(8-24)approximatelyFP(24-72). Results of the assay also showed that the levels of FVIII were significantly higher in the AB type plasmas than in the O type plasmas. PL-A and FFP units met the current quality requirements of the Korean Red Cross, in which the FVIII activity should have more than 0.7 IU/mL in more than 75% of the source plasma, as 85.0% and 82.5%, respectively. On the other hand, FP24 met the Canadian (Quebec) requirements for the source plasma, in which the FVIII activity should have more than 0.52 IU/mL in more than 75% of the source plasma, as 82.6%. CONCLUSION: For use of plasma frozen within 24 hours after phlebotomy (FP24) and plasma of specific blood type, European Pharmacopeia and WHO guidelines on quality control should be adopted for production of plasma-derived coagulation factors in Korea.

Establishment of Plasma Working Standards for the Performance and Quality Assurance of NAT Screening Tests for HIV, HCV and HBV / 대한수혈학회지

BACKGROUND: Since Jan. 2012, for performance evaluation of viral reagents, analysis of domestic samples has been recommended in order to obtain approval from the KFDA when they are first introduced to Korea. This regulation requires the standard domestic materials driven from locally infected samples. We tried manufacturing the plasma working standards of HBV, HCV, and HIV NAT using a mixed titer of viral loads. METHODS: Forty three HBV DNA positive plasmas, 25 HCV RNA positive plasmas, and 26 HIV RNA positive plasmas were evaluated according to viral load and genotype. Several plasma units, which had high-titer viral loads and the common viral genotypes in Korea, were selected as the source materials for each viral standard. To adjust the appropriate concentration based on the detectable range of variable viral reagents, the source plasma was diluted to several concentrations, divided into small vials, and analyzed for quantification. RESULTS: The 13 plasma working standards, which had variable viral loads for the mixed titer performance panel of HIV, HCV, and HBV NAT, were produced. CONCLUSION: These national standard materials were first produced in order to supply the mixed titer performance panel for the viral NAT reagent of the level IV transfusion related high-risk group in Korea.

Analysis for Human Immunodeficiency Virus 1 Subtype in Korean Blood Donors / 대한수혈학회지

BACKGROUND: Genetic variants of virus appear to differ depending on the country, race, infection route, and so on. To characterize the main HIV subtype in infected blood donors and inquire about the route of HIV infection, we analyzed HIV subtype for samples that showed reactive results on the anti-HIV 1/2 and HIV-1 NAT test from September 2007 to February 2010. METHODS: To identify the HIV-1 subtype of the 90 samples that showed reactive results on the anti-HIV test and HIV-1 NAT, we performed HIV 1/2 Western blot assay, HIV RNA quantitative assay, HIV-1 nested PCR, and HIV-1 RNA sequencing. RESULTS: A total of 85 samples (94.4%) were confirmed to be HIV-1 subtypes. Among them, 82 samples (96.5%) were subtype B; and subtype A, C, and G was confirmed for one case each (1.2% for each case). We could not identify the subtype of the other five samples. One of them was amplified by nested PCR, but was not confirmed of the subtype, and four samples were not amplified even by nested PCR. CONCLUSION: The main HIV-1 subtype among the HIV-infected blood donors was confirmed to be subtype B. In addition, we identified one case each of HIV-1 subtype A, C, and G, which was not detected in blood donors in the past. It appeared that the route of HIV infection in Korea had become complicated. Therefore, we concluded that continuous research for HIV subtype analysis and efficient management of blood donors is needed.

Complete Sequencing of the ABO Alleles of the Common ABO Group and Rare ABO Subgroups in Koreans / 대한수혈학회지

BACKGROUND: Complete sequencing, except for intron 1, of the ABO allele in some populations has been reported. However, so far, one report on complete sequencing of the ABO gene in three Korean families with normal ABO phenotypes has been published. This study aimed to establish a reference database of common ABO alleles in Koreans. METHODS: Screening of common ABO alleles, including homozygote form, was performed by direct sequencing of exons 6 and 7 and by real-time PCR using displacing probes in 95 healthy donors. Genomic DNA from the common ABO group (n=8) and some ABO subgroups (n=7) was used in complete sequencing (except for intron 1) of the ABO allele. RESULTS: The sequences of B101/B101 (n=1), O01/O01 (n=1) were identical with the corresponding sequences registered in Genebank. A102 and A105 had a common point mutation, 1142 C>T in intron 4. A102 (n=3/11) and O02 (n=3/3), selected by sequencing of exons 6 and 7, were reclassified into A105 and O65 by whole genomic sequencing, respectively. Analytic results for ABO subgroups were as follows: B3, B101/O01 (n=3) and B101/O02 (n=1); A1B3, A102/B101 (n=1) and A105/B101 (n=1); Ax, A102/O01 (n=1). CONCLUSION: We established a reference database of common ABO alleles in Koreans and found that the molecular basis of introns of ABO alleles in the Korean population differs from that reported in previous studies of other populations.

Two A(weak)B Cases with Aw10 Allele Separated by Allele-specific Sequencing / 대한수혈학회지

We separated an Aw10 allele by allele-specific sequencing in two Aw10/B101 samples that had the AweakB phenotype. Two samples with the A102/B101 genotype were also tested as a control. The reverse primers using position 930 at exon7 were designed for allele-specific sequencing. The differential positions were a total of 52 points for distinguishing the A-allele from the B-allele. Although overlaps with another haplotype allele that showed a minor chromatographic peak were observed in almost all the points, the specific allele-separation rate was 100% (52/52) by assessing the dominance in the chromatographic peak height. Based on the separation rate in the two cases with Aw10/B101 and the two AB controls, allele-specific sequencing is a convenient and reliable method for the separating the A-allele and B-allele in a clinical laboratory.

Comparison of Methods for Detecting Bacterial Contamination in Platelet Concentrates / 대한수혈학회지

BACKGROUND: Bacterial contamination of platelets represents the highest infectious risk for a transfusion. In this study, we evaluated 2 culture-based systems that have been approved by the US FDA for bacterial screening. METHODS: Platelet concentrates were inoculated with 5 bacterial species to give a final concentration of 10(0), 10(1) and 10(2) CFU/mL. Samples for culture were taken immediately after inoculation (0 hr sample) and after 24 hrs (24 hr sample). For the BacT/ALERT 3D system, a 10 mL sample was inoculated into an aerobic culture bottle and incubated for 7 days. For the Pall eBDS system, 3 mL samples were taken from the 0 hr and 24 hr samples, respectively. The samples were incubated for 24 hrs and 30 hrs. RESULTS: Both systems detected all inoculated units both in the 0 hr and 24 hr samples, except for units inoculated with K. pneumoniae. Eleven units out of 30 units inoculated with K. pneumoniae were detected by the BacT/ALERT 3D system in the 24 hr samples. The Pall eBDS system detected 8 of 30 units in the 24 hr samples. CONCLUSION: Implementation of either system will decrease the risk of transfusing bacterially contaminated platelets. However, testing for bacterial contamination will not completely prevent septic transfusion reactions; pathogen inactivation that is now available should also be considered as an alternative method to reduce the risk of bacterial contamination.

Application of Real-Time PCR for ABO Genotyping for Large-scale Population Screening / 대한수혈학회지

BACKGROUND: For large-scale population screening, the method of ABO genotyping needs to be simple, accurate and cost-effective. The real-time PCR method has been introduced and it is suitable for dealing with large numbers of specimens. In this study, we examined the ABO genotyping of 1,700 residents of Jeollanam-do for an epidemiologic study by applying the real-time PCR method. METHODS: Genomic DNA was extracted from the peripheral blood samples of 1,700 residents of Jeollanam-do between July 2004 and January 2006 and these samples were stored at -70degrees C. The ABO genotype in all the samples was determined by four-color real-time PCR using displacing probes and three cases that had an atypical real time PCR pattern were confirmed by direct sequencing and PCR-based cloning of exons 6&7 of the ABO gene. RESULTS: The genotyping results of 1,700 samples included O/O (25.6%), A/A (9.1%), A/O (29.1%), B/B (4.5%), B/O (19.8%) and A/B (11.9%), and the allele frequencies of O, A and B were 50.1%, 29.5% and 20.4%, respectively. The frequency of the O allele was lower in the residents of Jeollanam-do than that previously reported for the residents of Kangwon-do (P=0.014), while the frequency of the A allele was higher in the residents of Jeollanam-do than that previously reported for the residents of Kangwon-do (P=0.003). The three cases with atypical results were revealed to be B101/O24, Bvar(296C>T)/O01 and B101/Ovar(801G>T). It takes 6 days to perform ABO genotyping on 1,700 samples by a calculation per test. CONCLUSION: ABO genotyping by real-time PCR using displacing probes can be useful for mass screening for ABO genotyping. In Korea, the frequency of the ABO allele was significantly different among different regions.

Evaluation of the Virus-elimination Efficacy of Nanofiltration (Viresolve NFP) for the Parvovirus B19 and Hepatitis A Virus / 대한진단검사의학회지

BACKGROUND: The safety of plasma derivatives has been reinforced since 1980s by variable pathogen inactivation or elimination techniques. Nucleic acid amplification test (NAT) for the source plasma has also been implemented worldwide. Recently nanofiltration has been used in some country for ensuring safety of plasma derivatives to eliminate non-enveloped viruses such as parvovirus B19 (B19V) and hepatitis A virus (HAV). We evaluated the efficacy of nanofiltration for the elimination of B19V and HAV. METHODS: To verify the efficacy of nanofiltration, we adopted a 20 nm Viresolve NFP (Millipore, USA) in the scaling down (1:1,370) model of the antithrombin III production. As virus stock solutions, we used B19V reactive plasma and porcine parvovirus (PPV) and HAV obtained from cell culture. And 50% tissue culture infectious dose was consumed as infectious dose. The methods used to evaluate the virus-elimination efficacy were reverse-transcriptase polymerase chain reaction for B19V and the cytopathic effect calculation after filtration for PPV and HAV. RESULTS: B19V was not detected by RT-PCR in the filtered antithrombin III solutions with initial viral load of 6.42x10(5) IU/mL and 1.42x10(5) IU/mL before filtration. The virus-elimination efficacy of nanofiltration for PPV and HAV were > or =10(3.32) and > or =10(3.31), respectively. CONCLUSIONS: Nanofiltration would be an effective method for the elimination of B19V and HAV. It may be used as a substitute for NAT screening of these viruses in source plasma to ensure safety of plasma derivatives in Korea.

Investigation of the Prevalence of Human Parvovirus B19 DNA in Korean Plasmapheresis Donors / 대한진단검사의학회지

BACKGROUND: To ensure the safety of plasma derivatives, some countries have been screening for the human parvovirus B19 (B19V) antigen or DNA in blood donors. We investigated the prevalence of B19V DNA and anti-B19V antibodies in Korean plasmapheresis donors to evaluate the necessity of B19V DNA screening test. METHODS: Plasma samples were collected between March and July 2008 from 10,032 plasmapheresis donors. The B19V DNA test was performed using the LightCycler 2.0 (Roche, Germany) with quantification kits. Anti-B19V IgM and IgG were tested in 928 randomly selected samples from the 10,032 donors using recomWell Parvovirus B19 ELISA IgM, IgG assay (Mikrogen, Germany). RecomLine Parvovirus B19 LIA IgG, IgM assay (Mikrogen, Germany) was used to analyze the epitopes of antibodies in donors showing positive results for B19V DNA and anti-B19V antibodies. DNA sequencing was performed to identify the genotypes. RESULTS: The prevalence of B19V DNA was 0.1% (10/10,032). Virus titers in B19V DNA positive donors were less than 10(5) IU/mL (range: 2.7x10(1)-3.2x10(4) IU/mL) except for 1 donor (1.33x10(8) IU/mL). All the isolated B19V DNAs from 6 donors were identified as genotype I. Nine out of 10 B19V DNA positive donors also possessed anti-B19V IgG only or IgG and IgM. The prevalence of anti-B19V IgG was 60.1% (558/928). CONCLUSIONS: The prevalence of B19V DNA in Korean blood donors was not high and most donors also possessed neutralizing anti-B19V antibodies. Thus, the implementation of a B19V screening test for Korean blood donors does not appear to be imperative.

Determining the Cause of Discrepant Results in HCV NAT Comparative Tests / 대한수혈학회지

BACKGROUND: The Korean Red Cross blood laboratory centers have been performing comparative tests for NAT reactive specimens since February 2005. However, five discrepant specimens were found in HCV-diluted specimens between 2007 and 2008 and the reasons for this has been investigated. METHODS: For the five discrepant specimens, the HCV RNA concentration was measured in 5 tubes for each speciment. Subsequently, in order to compare the sensitivity of the low titer specimens measured by RT-PCR and TMA, comparative tests of diluted samples were examined six times per sample. Finally, the genotype was tested in order to determine the characteristics of the discrepant samples. RESULTS: Result of the quantitative tests for HCV RNA demonstrated that aliquots of the plasma bag were homogenous in term of viral load quantitation. As a result of the comparative test, all samples were found to contain over 1.0x10(1) IU/mL as detected by the two analytical systems. In contrast, those less than 1.0x10(1) IU/mL were not entirely detected by the two systems. CONCLUSION: It was impossible to completely detect using the two NAT system and the detection rates for both systems were equivalent for the samples examined. In particular, with respect to HCV, it may be undetectable on the NAT test because viral load decreases rapidly before and after sero-conversion. This result indicates that anti-HCV and NAT should be performed together as an HCV screening test prior to blood donation.

Establishment of a Korean Hepatitis B Surface Antigen Low Titer Performance Panel for Performance Validation of Hepatitis B Surface Antigen Immunoassays / 대한수혈학회지

BACKGROUND: A range of well characterized materials are needed for validating the performance of hepatitis B surface antigen (HBsAg) immunoassays. These materials are purchased currently from overseas manufacturers at a high cost and with limited quantity. This study was conducted to establish an HBsAg low titer performance panel for use as a national standard for validation of HBsAg immunoassays in Korea. METHODS: 476 plasma units reactive on blood donor screening were collected HBsAg was tested using 3 enzyme immunoassays (EIA) and 1 chemiluminescence immunoassay (CIA). Units reactive on the CIA assay or on 2 or more immunoassays were subjected to hepatitis B virus (HBV) DNA quantification, HBV genotyping and subtyping. Units reactive on HBV DNA quantification were confirmed for HBsAg by neutralization. Candidates for the panel were subjected to a collaborative study performed at 7 laboratories using 7 immunoassays. RESULTS: Eleven HBsAg positive units were selected for the low titer performance panel based on HBsAg immunoassay, HBV DNA quantification, HBV genotyping and subtyping results. The range of the HBsAg concentration of the panel members was 0.05~1.28 IU/mL. Two HBsAg negative units were also included as negative controls. CONCLUSION: As a result of this study, a low titer performance panel [KFDA standard (08/028); HBsAg low titer performance panel (BTRL HBV/LP)] for validation of HBsAg immunoassays has been established as a Korean national standard. Use of this panel will improve performance assessment of HBsAg immunoassays. Because the performance of immunoassays cannot be assessed properly with a limited number of panels, continuous efforts are needed to develop a range of performance panels.

A Proposal for Developing a National Quality Assurance Program for Donor Bloodassays / 대한수혈학회지

BACKGROUND: Viral screening assays performed for blood donors are required to have high sensitivity because false negative results can lead to transfusion-transmitted infections. To minimize the number of false negative cases, a systematic quality assurance program is required to verify donor screening tests. METHODS: The current status of quality assurance (QA) for blood donor screening tests in Korea and other countries was reviewed. A quality assurance program using the national standards of the Korea Food and Drug Administration (KFDA) was done as a pilot study to evaluate both the need for such a program and the feasibility of such a program. RESULTS: Singapore had a national quality assurance programs for the anti-HIVdonor screening tests. In the United Kingdom, all laboratories use the NIBSC working standards as QA materials for the donors screening. Ninety-five % (84/80) of blood centers replied that they would participate in a national quality assessment program and 92% (84/77) of the blood centers also felt that an independent organization should be designated to operate the program. Quality control materials with a weak reactivity should be included in a quality assessment program for donor screening. CONCLUSION: We propose 2 models for a National Quality Assurance Program (NQAP). In the first model, an independent national reference laboratory (NRL) needs to be established that operates the national quality assurance program. The second model involves the integration of the national quality assurance program for donor screening into the External Quality Assurance Survey run by the Korean Association of Clinical Assurance for Clinical Laboratory (KAQACL) using the national standards.