Analysis of HCV positive plasma and manufacturing of HCV RNA national standard candidate / 대한수혈학회지

BACKGROUNDS: Standardization of nucleic acid amplification techniques (NAT) which can be achieved by the use of standard to validate reproducibility and sensitivity in each assay run is necessary before the introduction of such methods for routine screening of blood and blood products for viral contaminants. The objective of this study was to analyze the serological and genotypic characteristics of HCV positive plasmas and to manufacture the HCV RNA national standard candidate. METHODS: We obtained three plasmas from Blood Transfusion Research Institute, Korea, with highly positive HCV RNA plasmas (#37, #40, #46) and with normal plasma for dilution. All the plasmas were confirmed by enzyme immunoassay (EIA) test for anti-HIV, HBsAg, anti-HCV and by polymerase chain reaction(PCR) for HBV DNA, HIV RNA, HCV RNA. The genotypes of those were confirmed by INNO-LiPA HCV II. HCV RNA national standard candidate was manufactured by dispensing the diluted plasma into about 2,000 vials. Each vial was rapidly frozen using liquid nitrogen and was kept in refrigerator at -70 degrees C. RESULTS: All plasmas were identified as anti-HIV, HBsAg, HBV DNA, and HIV RNA negative plasmas. The genotypes of those were confirmed as 1b for #37, 1b or 2 for #40 and 2a or 2c for #46, respectively. Sample #37 was selected as the candidate material. After manufacturing, we obtained 1,944 vials for the candidate. CONCLUSION: In this study, we analyzed HCV positive plasmas and manufactured the HCV RNA national standard candidate. In near future, this material would be established for national standard to increase in the safety of blood and blood products in Korea.

Necessity of Anti-HBc and Anti-HBs Screening in Korean Blood Donation Program: Study using LG Anti-HBc and LG Anti-HBs ELISA Kit and HBV Nucleic Acid Amplification Test / 대한수혈학회지

BACKGROUND: Post-transfusion hepatitis B remains a risk for recipients of HBsAg negative bloods in Korea. The usefulness of anti-HBc screening for blood donors to reduce the risk of HBV transmission was evaluated in this study using LG Anti-HBc and LG Anti-HBs ELISA (LG Chemicals, Seoul, Korea) and HBV nucleic acid amplification test. METHOD: Sera from 2,274 HBsAg-negative blood donors were tested of anti-HBc and anti-HBs by LG Anti-HBc and LG Anti-HBs ELISA, respectively. Using 260 samples from HBsAg-negative blood donors and 62 FANA-positive samples, reactivity to LG Anti-HBc ELISA were compared with COBAS CORE Anti-HBc EIA (Roche Diagnostics, Basel, Switzerland). The precision of LG Anti-HBc was also tested. The nucleic acid amplification of 97 primary pools prepared from 2,274 samples was carried out, and then HBV presence was confirmed in individual samples. RESULT: Of 2,274 HBsAg-negative blood donors, 531 (23.4%) were positive for anti-HBc and 32 (1.4%) were anti-HBc positive/ anti-HBs negative. The concordance rate of LG Anti-HBc ELISA and COBAS was 97.8% (315/322). The intra-run and inter-run coefficient of variation was 4.7-10.2% and 2.5-11.4%, respectively. Thirteen pools showed initial positive in HBV PCR, but seven pools (53.8%) were finally found to be false positive. Of six true positive pools, seven samples were confirmed to have HBV DNA. The HBV detection rate was 6.3% (2/32) among donors whose results were anti-HBc positive/ anti-HBs negative. CONCLUSION: Among screen-negative blood donors, 6.3% of donors whose seroreactivity was anti-HBc positive/ anti-HBs negative were positive for HBV by nucleic acid amplification test, while donors showing such seroreactivity were only 1.4%. It is suggested that an introduction of anti-HBc and anti-HBs testing in Korean Blood Donation program be efficient to attain safety from HBV transmission.

Evaluation of Vironostika HIV Uni-Form II Ag/Ab Enzyme Immunoassay Kit for Simultaneous Detection of Antigen and Antibody of HIV / 대한수혈학회지

BACKGROUND: It has been estimated that 1 unit per 493,000 blood donations could transmit HIV by infected persons in seroconversion window in America. The 4th generation enzyme immunoassay (EIA) kits which are designed to detect HIV antigen and antibody simultaneously, could reduce the period of seroconversion window and thereby increase the safety of donated bloods without additional expenses. METHODS: Sensitivity and specificity of Vironostika HIV Uni-Form II Ag/Ab (Organon Technika, Boxtel, Netherlands) were evaluated using 53 samples (11 western blot positive samples and 42 sera from BBI panel) and 391 samples (282 healthy donors, 20 anti-HCV positive sera and 89 FANA positive sera), respectively. Seroconversion window was compared with that of COBAS CORE Anti-HIV-1/HIV-2 EIA DAGS (Roche Diagnostics, Basel, Switzerland) using 6 kinds of BBI seroconversion panel. RESLUTS: Sensitivity was 100% (53/53). Aggregated specificity was 99.5% (389/391), while all the samples from the healthy donors showed negative (282/282). COBAS CORE Anti-HIV-1/HIV-2 EIA DAGS also showed 100% sensitivity (53/53) and 100% specificity (391/391). Vironostika HIV kit detected HIV-1 infection earlier about 9.8 days than COBAS CORE Anti-HIV-1/HIV-2 EIA DAGS. CONCLUSION: Sensitivity and specificity of Vironostika HIV kit were as good as those of COBAS CORE kit. Vironostika HIV kit, however, could get more safety of donated bloods than the 3rd generation EIA such as COBAS CORE Anti-HIV-1/HIV-2 EIA DAGS, in that it can reduce seroconversion window of HIV infection.

Positive Rate of HCV RNA in Anti-HCV Immunoblot Indeterminate Samples from Blood Donors and Analysis of Reactivity of Enzyme Immunoassay Kits to Indeterminate Samples / 대한수혈학회지

BACKGROUND: Positive rate of HCV RNA in anti-HCV immunoblot indeterminate samples from Korean blood donors was investigated in this study. Futhermore, reactivity of enzyme immunoassay kits was evaluated according to patterns of band reactivity and RNA positivity of indeterminate samples. METHODS: HCV RNA was tested from a total of 180 samples that had been repeatedly reactive to LG HCD 3.0 or DONG-A HCV 3.0 and further confirmed to be indeterminate by LG HCD CONFIRM at 14 Korean Red Cross Blood Centers in 1997. Correlation between HCV RNA and reactivity to each recombinant antigens was analysed. Three kinds of EIA kits such as HCD 3.0, DONG-A HCV 3.0 and Cobas Core Anti-HCV EIA kits were tested of their reactivity to 56 samples that had shown single band positivity on LG HCD CONFIRM. RESLUTS: HCV RNA was detected in 11 (6.1%) of 180 samples. Positivity of 897 band showed positive correlation with HCV RNA positivity (p<0.001), while Core518 showed negative correlation (p<0.001). DONG-A HCV 3.0 showed negative reaction to two samples with anti-897 specificity and HCV RNA, while LG HCD 3.0 and Cobas Core HCV showed negative reaction to one sample with anti-EIE2NS4 and HCV RNA. CONCLUSION: Positive rate of anti-HCV immunoblot indeterminate samples from Korean blood donors was 6.1%. In case of indeterminate results by LG HCD CONFIRM, positive reaction to 897 band highly suggests the presence of HCV RNA, while Core518 the absence of HCV RNA. It is highly recommended that specificity of Core518 antigen be increased in LG HCD 3.0 or LG HCD CONFIRM and sensitivity of recombinant antigen from the 3rd non-structural region of HCV genome be increased in DONG-A HCV 3.0.

Analysis of Blood Donation History of Korean Malaria Patients / 대한임상병리학회지

BACKGROUND: After the resurgence of endemic malaria case in 1993, the number of malaria cases is increasing in succeeding years and most of patients were soldiers who served in the northern parts of Kyeonggi-do and Kangwon-do. Because group donations of blood from soldiers are frequent in these area, it is possible that donated blood from these area cause malaria. So we examined blood donation history of malaria patients to know their donation behavior. METHODS: The subject was 1,671 malaria patients who were diagnosed in 1997 and referred to blood transfusion research institute and their past donation history, time and frequency of donation were examined. The database consisted of malaria patients and blood donors who are known to be related with transfusion-transmitted malaria has been retrieved at each red cross blood center for every blood donors. The results were analyzed from January to December, 1998. RESULTS: About 60% (1,017) of 1,691 malaria patients in 1997 had donated their blood before diagnosis. The number of one time donation was 268; two time 289; more than three time was 460. Two hundred thirty six donors were checked by malaria registry file. In 236 donors, 92 cases were diagnosed with malaria, 96 cases were suspected to have malaria, 48 cases were namesakes. Conclusion: Because some malaria patients donate their blood after their diagnosis, it would be necessary to operate 'the computerized retrieving programme'to detect their donation after the diagnosis. Also, an education for malaria patients for their risk of transmitting malaria and strict history taking from donors for malaria will be required.

Seroincidence of Hepatitis B Virus among Korean Blood Donors / 대한수혈학회지

BACKGROUND: Seroincidence of hepatitis B virus (HBV) among Korean blood donors has not been reported. This study was conducted to calculate the seroincidence of HBV among blood donors and to estimate the risk of post-transfusion hepatitis B by donated blood in window period of infection. METHODS: HBV seroincidence was calculated among repeat-donors who had donated from Nov. 1994 through Dec. 1996. To calculate the person-years, the database of the Korean National Red Cross was used in which results for HBsAg enzyme immunoassay were filed up. The observed incidence was adjusted by interdonation interval of incident cases, who were defined as donors showing seroconversion. The risk of post-transfusion hepatitis B by donated bloods in window period of infection was estimated. RESULTS: HBV seroincidence was estimated to be 180.85/100,000 person-years. This was adjusted as 602.83/100,000 person-years by considering interdonation intervals. The risk of post-transfusion hepatitis B was estimated to be 974 units per one million of whole blood units due to be in window period of infection. CONCLUSION: The estimated seroincidence of HBV among Korean blood donors and thereby the risk of HBV transmission by donated bloods in window period of infection was about 50 to 60 times higher than those of Japan and United States of America.

Seroincidence of Hepatitis B Virus among Korean Blood Donors

BACKGROUND: Seroincidence of hepatitis B virus (HBV) among Korean blood donors has not been reported. This study was conducted to calculate the seroincidence of HBV among blood donors and to estimate the risk of post-transfusion hepatitis B by donated blood in window period of infection. METHODS: HBV seroincidence was calculated among repeat-donors who had donated from Nov. 1994 through Dec. 1996. To calculate the person-years, the database of the Korean National Red Cross was used in which results for HBsAg enzyme immunoassay were filed up. The observed incidence was adjusted by interdonation interval of incident cases, who were defined as donors showing seroconversion. The risk of post-transfusion hepatitis B by donated bloods in window period of infection was estimated. RESULTS: HBV seroincidence was estimated to be 180.85/100,000 person-years. This was adjusted as 602.83/100,000 person-years by considering interdonation intervals. The risk of post-transfusion hepatitis B was estimated to be 974 units per one million of whole blood units due to be in window period of infection. CONCLUSION: The estimated seroincidence of HBV among Korean blood donors and thereby the risk of HBV transmission by donated bloods in window period of infection was about 50 to 60 times higher than those of Japan and United States of America.(Korean J Blood Transfusion 10(1): 1-4, 1999)