CD34 and p53 Immunohistochemical Stains Differentiate Hypocellular Myelodysplastic Syndrome (hMDS) from Aplastic Anemia and a CD34 Immunohistochemical Stain Provides Useful Survival Information for hMDS

BACKGROUND: The presence of significant dysplasia in bone marrow (BM) aspirates helps to distinguish between hypocellular myelodysplastic syndrome (hMDS) and aplastic anemia (AA). Occasionally, diluted BM aspirates make it difficult to recognize dysplastic changes and can also negatively affect the detection of cytogenetic abnormalities in hMDS. We evaluated the usefulness of CD34 and p53 immunoreactivity for discriminating between hMDS and AA and for estimating survival outcomes in hMDS patients. METHODS: BM clot section (BMC) or BM biopsy (BMB) specimens were obtained from 64 hMDS/AA patients (33 with hMDS and 31 with AA) and seven controls. Immunohistochemical (IHC) staining for CD34 and p53 was performed by using the EnVision detection system (Dako, Denmark). We compared the results of IHC staining, BM findings, and chromosomal analyses, and determined overall survival outcomes. RESULTS: The number of CD34- and p53-positive BM cells was higher among the patients with hMDS than among the patients with AA (P<0.001 and P=0.001, respectively). hMDS patients with increased CD34-positive cells had significantly poorer survival outcomes compared with those with normal number of CD34-positive cells (P=0.013). CONCLUSIONS: CD34 and p53 IHC stains of BMC or BMB provide useful information for differentiating between hMDS and AA. CD34 IHC staining of BMC or BMB also provides useful information for estimating survival outcomes in hMDS patients.

Endothelial cells in peripheral blood smear: an artifact?

No abstract available.

Minimal Residual Disease Detection in Acute Leukemia Patients by Flow Cytometric Assay of Cross-lineage Antigen Expression / 대한진단검사의학회지

BACKGROUND: It has been demonstrated that flow cytometric detection of minimal residual disease (MRD) has a prognostic significance in the treatment of patients with acute leukemia. We investigated the significance of flow cytometric MRD detection for the first time in Korea. METHODS: We analyzed the results of MRD detection in morphologically complete remission bone marrow aspirates from 89 patients with newly-diagnosed or relapsed acute leukemia, in which leukemic cells had cross-lineage antigen expression. Patients were grouped based on MRD frequencies: > or =1.0%, high MRD; <1.0%, low MRD. RESULTS: Forty-seven ALL patients consisted of 10 with high and 37 with low MRD levels. Patients with high MRD levels showed a tendency of more frequent relapse than those with low MRD levels (40.0% and 13.5%, respectively) (P=0.08). High MRD group showed a tendency of short relapse-free survival (RFS) and overall survival (OS), although the differences were not statistically significant. Forty-two AML patients consisted of 16 with high and 26 with low MRD levels. There were no correlations between the MRD levels and relapse rate, RFS or OS. AML patients with high MRD levels showed significantly higher rate of unfavorable cytogenetic risk categories and lower rate of favorable risk categories (P=0.03). CONCLUSIONS: MRD detection by flow cytometric assay of cross-lineage antigen expression would be useful in predicting treatment outcome in patients with ALL rather than AML. We expect that the establishment of the standardization of methods, time to test or antibody combination would be achieved through further trials in this country.

Detection of Vancomycin-resistant Enterococci using Multiplex Real-time PCR Assay and Melting Curve Analysis / 대한진단검사의학회지

BACKGROUND: We developed and evaluated the utility of a multiplex real-time PCR assay that uses melting curve analysis and allows simultaneous identification of vancomycin-resistant genotypes and clinically relevant enterococci. METHODS: The specificity of the assay was tested using 4 reference strains of vancomycin-resistant enterococci (VRE) and 2 reference strains of vancomycin-susceptible enterococci. Ninety-three clinical isolates of enterococci with different glycopeptide-resistant phenotypes were genotyped and identified using a multiplex real-time PCR assay and melting curve analysis. RESULTS: Representative melting curves were obtained for Enterococcus faecium, Enterococcus faecalis, vanA-containing E. faecium, vanB-containing E. faecalis, Enterococcus gallinarum, and Enterococcus casseliflavus. Phenotypic and genotypic analysis of the isolates revealed same results for 82 enterococcal isolates, while in 4 isolates, the glycopeptide-resistant phenotypes were inconsistent with the glycopeptide-resistant genotypes and in the 4 other isolates, species could not be accurately identified. Three isolates with mixed strains, which were detected by the PCR assay, could not be correctly identified using phenotypic methods. CONCLUSIONS: VRE genotyping and identification of clinically relevant enterococci were rapidly and correctly performed using multiplex real-time PCR assay and melting curve analysis.

A Case of CD5 Negative Chronic Lymphocytic Leukemia

Neoplastic lymphoid cells of chronic lymphocytic leukemia (CLL) typically co-express CD5 and CD23. CD5-negative CLL is a rare variant of CLL; only 1 case of it has been reported in Korea. We describe a case of CD5-negative CLL. A 48-year-old female complained of a palpable neck mass that had been present for over 1 year. The initial WBC count was 7,300/microliter, with 69% lymphocytes. A CT scan revealed multiple enlarged lymph nodes, both of each in the neck, axilla, and common iliac areas. The athologic results of the cervical lymph node was consistent with small lymphocytic lymphoma, of which tumor cells do not express CD5. In a bone marrow study, neoplastic lymphoid cells comprise 34.8% of all nucleated cells, which showed small size, round nuclei with clumped chromatin, and sparse cytoplasm. Immunophenotyping of small lymphoid cells displayed phenotypes that were CD45-, CD23-, CD20-, and CD19-positive, but CD5-negative. The patient was diagnosed with CD5-negative CLL, and has been followed up for 2.5 years after chemotherapy.

Subgenotype and Serotype Analysis of Hepatitis B virus in Korean Chronic Hepatitis B Patients Under Treatment / 대한진단검사의학회지

BACKGROUND: Hepatitis B virus (HBV) detected in Korean patients almost belongs to genotype C, which is subdivided into subgenotype C1 (or Cs) and C2 (or Ce). It was recently reported that the risk of hepatocellular carcinoma is different between subgenotype C1 and C2. Thus, we studied the distribution of subgenotypes of HBV in Korean chronic hepatitis B (CHB) patients. METHODS: Specimens of 421 patients, who were diagnosed as CHB and underwent antiviral treatment, were used. After sequence analysis for HBV S gene, subgenotype was identified through phylogenetic analysis. Utilizing the same sequence data, the distribution of serotypes was also investigated. RESULTS: Among 421 patient specimens, genotype C was found in 419 (99.5%) and genotype B in 2 (0.5%). Among the genotype C strains, 417 strains were C2 subgenotype and 2 strains were mixed subgenotypes. However, C2 was evidently found even in the mixed sequences. Serotypes of 419 HBV with genotype C were classified as follows: adr, 385 (91.9%), adw, 22 (5.3%), ayr, 2 (0.4%) and mixed serotype, 10 (2.3%). Serotype of both HBV with genotype B was adw. CONCLUSIONS: It was found that HBV detected in Korean CHB patients under treatment almost all belong to the C2 (Ce) genotype.

The effectiveness of biochemical indexes for evaluating the nutrition states of children / 소아과

PURPOSE: This study has been conducted to analyze whether the biochemical nutrition indexes might be useful and effective for evaluating the nutrition states of children. METHODS: We evaluated 269 children, aged 3-9 years old, who had visited Gangneung Asan Hospital for elective surgery from January 2006 to December 2007, and examined their anthropometric and preoperative laboratory data with retrospective analysis. The children were classified into underweight, normal weight, overweight, and obese groups according to body mass index (BMI). The biochemical nutrition indexes (total lymphocyte count (TLC), hemoglobin, hematocrit, serum albumin, cholesterol, et al) of each group were then analyzed statistically. RESULTS: None of the groups showed statistically significant differences in TLC. Serum albumin decreased significantly in the underweight group. Red blood cell (RBC) count, hemoglobin, hematocrit, and serum total cholesterol in the obese group were higher than in the normal weight group. None of the groups showed statistically significant increase in mean corpuscular volume or mean corpuscular hemoglobin, and it seems that the increase of hemoglobin and RBC count in the overweight and obese groups is due to the enhancement of erythropoiesis rather than iron metabolism. However, in females, almost all nutrition indexes except albumin were statistically significantly poor. CONCLUSION: Serum albumin, total cholesterol, RBC count, hemoglobin, and hematocrit were useful as nutrition indexes. However, except for albumin, these indexes were significantly poor for females. More control studies are needed to confirm the effectiveness of biochemical indexes for evaluating the nutritional state of children.

Development of a System for Extracting the Information of Candidate Tumor Markers Reported in Biomedical Literatures / 대한진단검사의학회지

BACKGROUND: Since the human genome project was completed in 2003, there have been numerous reports on cancer and related markers. This study was aimed to develop a system to extract automatically information regarding the relationship between cancer and tumor markers from biomedical literatures. METHODS: Named entities of tumor markers were recognized by both a dictionary-based method and machine learning technology of the support vector machine. Named entities of cancers were recognized by the MeSH dictionary. RESULTS: Relational and filtering keywords were selected after annotating 160 abstracts from PubMed. Relational information was extracted only when one of the relational keywords was in an appropriate position along the parse tree of a sentence with both tumor marker and disease entities. The performance of the system developed in this study was evaluated with another set of 77 abstracts. With the relational and filtering keyword used in the system, precision was 94.38% and recall was 66.14%, while without the expert knowledge precision was 49.16% and recall was 69.29%. CONCLUSIONS: We developed a system that can extract relational information between a tumor and its markers by incorporating expert knowledge into the system. The system exploiting expert knowledge would serve as a reference when developing another information extraction system in various medical fields.

Performance Evaluation of Abbott RealTime HBV Quantification Kit for HBV Viral Load by Real-Time PCR / 대한진단검사의학회지

BACKGROUND: Hepatitis B virus (HBV) DNA quantification is necessary for starting and monitoring of antiviral therapy in patients with chronic hepatitis B. This study was intended to assess the clinical performance of Abbott RealTime HBV Quantification kit (Abbott Laboratories, USA). METHODS: The performance was evaluated in terms of precision, linearity, detection sensitivity, cross-reactivity, and carry-over. A correlation with the Real-Q HBV Quantification kit (BioSewoom Inc., Korea) was also examined using serum samples from 64 patients diagnosed with chronic hepatitis B and underwent lamivudine therapy in Asan Medical Center. We verified the trueness of the system by comparing the outputs with the assigned values of the BBI panel (BBI Diagnostics, USA). RESULTS: Within-run and between-run coefficients of variation (CV) were 3.56-4.71% and 3.03-4.98%, respectively. Linearity was manifested ranging from 53 to 10(9) copies/mL and the detection sensitivity was verified to be 51 copies/mL. None of hepatitis C virus showed cross-reactivity. No cross-contamination occurred when negative and positive samples were alternatively placed in a row. It showed a good correlation with the Real-Q HBV (r2=0.9609) and the test results for the BBI panel were also well agreed to the assigned values (r2=0.9933). CONCLUSIONS: The performance of Abbott RealTime HBV Quantification kit was excellent; thus, it should be widely used in starting and monitoring of antiviral therapy in Korean patients with chronic hepatitis B.

Experience on Identification of Cross-Reactive Group Specificity Performed by Anti-human Globulin Panel Reactive Antibody Tests / 대한진단검사의학회지

BACKGROUND: Panel reactive antibody (PRA) is to screen and identify HLA antibody. Majority of antibody specificities in high-PRA are directed against cross reactive group (CREG). Thus, this study was to know the advantage of identifying CREG specificity and whether antibody specificities are changed according to CREG classification. METHODS: HLA class I antibodies were identified from 159 sera from 108 patients in Asan Medical Center, who had shown more than 5% PRA by anti-human globulin (AHG)-complement-dependent cytotoxicity (CDC). Tail analysis-based computer program was developed to identify specificities, applying both Rodey (R-ABC) and Takemoto (T-ABC) classification. The results were also compared with those obtained when without CREG application (ABC). RESULTS: Among 151 cases in which HLA specificities was identified, the frequency of CREG specificity was 22.5% in R-ABC and 27.2% in T-ABC. Eleven cases showed CREG specificities only in one classification. However, the individual antigen specificities in one hand were all included in the CREG identified in the other hand. CREG specificities in samples with PRA >50% (60%) were more frequently identified than those in samples with PRA < or =50% (9%) (in R-ABC, P<0.0001). Without applying CREG to interpretation, specificity was not identified in 9 cases. CONCLUSIONS: Application of CREG enhanced the rate of antibody identification. Antibody specificities of those cases where CREG specificities were different between Rodey and Takemoto classifications were almost the same when compared at the individual antigen level. Therefore, it was thought that it makes no difference to use any one of these two classifications in interpreting PRA.

Evaluation of BioSewoom(TM) HLA-A, -B, -C PCR/SSP Kit / 대한진단검사의학회지

BACKGROUND: Human leukocyte antigen (HLA) typing based on polymerase chain reaction (PCR) is rapidly replacing the conventional serological method. This study was intended to evaluate Bio- SewoomTM HLA-A, -B, -C PCR/SSP kit (BioSewoom SSP) which had recently been developed in Korea. METHODS: A total of 158 samples from domestic (21) and international (137) HLA proficiency testing (PT) were genotyped with BioSewoom SSP, and its results were compared to consensus results. For comparison with INNO-LiPA HLA-A, -B, -C Typing Kit (INNO-LiPA, Innogenetics, Belgium), 20 samples of Koreans were genotyped with both kits for each HLA-A, -B, -C locus. RESULTS: Among the 21 samples of domestic PT, BioSewoom SSP showed ambiguities as follows: 4 samples (19.0%) in HLA-A, 6 (28.6%) in HLA-B, and 1 (4.8%) in HLA-C. The ambiguities could be resolved by considering the allele distribution of Koreans. Among the 137 samples from international PT, BioSewoom SSP also showed ambiguities as follows: 12 samples (8.8%) in HLA-A, 26 (19.0%) in HLA-B and 6 (4.4%) in HLA-C. Considering the allele distribution of Koreans, the serologic equivalents obtained from BioSewoom SSP showed a full agreement with those of INNO-LiPA in all the loci tested. Twelve (0.007%) among 1,760 PCR reactions from the 21 samples of domestic PT and 20 patient samples produced faint nonspecific bands, but it was negligible. PCR failure of internal control just barely occurred (15 PCR reactions, 0.009%), but it had no bearing on allele assignment. CONCLUSIONS: The performance of BioSewoom SSP was comparable to that of INNO-LiPA. All the ambiguities could be resolved by considering the allele distribution of Koreans. It is concluded that BioSewoom SSP has good performance to be used in routine HLA laboratories.

Development of a Web-based Program for the Identification of Human Leukocyte Antigen Antibody Specificities / 대한진단검사의학회지

BACKGROUND: Panel reactive antibody (PRA) test is used to determine whether a patient awaiting transplantation is previously sensitized. Tail analysis algorithm is widely used to identify antibody specificities, but it is very difficult to perform manually. METHODS: To develop a web-based program, PHP (5.1.2), Apache (2.0.55), and MySQL (5.0.22) were used. Tail analysis algorithm was applied to identify specificities, which analyzed statistically 2 x 2 tables representing reactivities to broad antigens, splits and cross reactive groups (CREG). Exploiting two CREG classifications of Rodey (R) and Takemoto (T), antibody specificities were identified by 3 methods (ABC, R-ABC, T-ABC) simultaneously. Performance of the system was evaluated using 159 samples that showed > or =6 PRA% by a lymphocytotoxicity assay. RESULTS: A web-based system that can identify HLA antibody specificities was implemented on www.koreanhla.com. Among 159 samples tested, antibody specificities were identified in 151 (95.0 %), but not in 8 samples with PRA >97%. Among the 151 samples, 110 showed broad or split specificities and 41 CREG specificities. CONCLUSIONS: We developed a web-based computer program for the identification of HLA antibody specificities. Accessible to everyone on the internet, this program should be of help in sharing PRA results among laboratories.

Meta-analysis of the Association between HLA-DRB1 Allele and Rheumatoid Arthritis Susceptibility in Asian Populations

The aims of this study were to summarize results on the association of HLA-DRB1 with rheumatoid arthritis (RA) in Asians and to determine if the shared epitope (SE) hypothesis could explain the meta-analysis results. Among the papers published between January 1987 and July 2006 on RA susceptibility in Asian-Mongoloid populations (Korean, Japanese, Chinese, and Thai), 12 were selected for the metaanalysis. Mongoloid-Asian patients with RA had significantly higher frequencies of HLA-DRB1*0101, *0401, *0410, and *1001 than controls (OR 1.5-2.1, p<0.05 for association). When analyses were restricted to more ethnically homogeneous populations, HLA-DRB1*0405 showed a significant susceptibility to RA in Koreans (OR 5.65, 95% CI 4.32-7.39), whereas the HLA-DRB1*0301, *0403, *0406, *0701, *1301, and *1405 alleles showed protective association with RA (OR 0.32-0.70, p<0.05 for association). In conclusion, it was found that HLA-DRB1 *0101, *0401, *0405, *0410, and *1001 are susceptible, while HLA-DRB1* 0301, *0403, *0406, *0701, *1301, and *1405 are protective in Asian-Mongoloids. All the RA-associated alleles except DRB1*0301 could be explained by the structural model supporting the SE hypothesis that RA susceptibility is determined by the combination of amino acid residues at HLA-DR beta71 and beta74, not by beta71 alone.

Performance Evaluation of Real-Q HBV Quantification Kit for HBV DNA by Real-Time PCR / 대한진단검사의학회지

BACKGROUND: Hepatitis B virus (HBV) DNA quantification is important for the management of HBV infection and identification of the development of resistance. The susceptibility to contamination and more variable reproducibility of results with the conventional HBV DNA quantification method have raised the need of a more simple and accurate method for HBV DNA quantification. Real-time quantitative PCR assays recently introduced in the laboratory can meet these needs. In this study, we evaluated the performance of the Real-Q HBV Quantification kit developed in Korea. METHODS: We evaluated the recovery of DNA extraction, the interference of internal control, an analytical sensitivity, specificity, and reproducibility, a clinical specificity, and a reportable range of the Real-Q HBV Quantification kit. The quantification result was also compared to that obtained by the Digene Hybrid-Capture II. RESULTS: The mean percent recovery was 108.6% and there was no interference with the internal control on DNA extraction. None of HIV, hepatitis C virus, or cytomegalovirus showed a cross-reactivity with HBV. This assay detected HBV DNA in a linear range from 10(2) to 10(10) copies/mL, with the detection limit of 56 copies/mL. The assay exhibited a low within-run CV (coefficient of variation) (8.7-11.9%), between-run CV (10.5-14.7%), and between-day CV (13.2-21.4%). No HBV DNA was detected in any of 100 samples without HBV, resulting in a clinical specificity of 100%. The levels of HBV DNA showed a good correlation with those determined with Digene Hybrid-Capture II (R2=0.9827). CONCLUSIONS: The Real-Q HBV Quantification kit showed a good analytical sensitivity, specificity, and high reliability with a broad reportable range. This assay should be clinically useful in managing patients with HBV infection.

Installation of Data Management System for Point-of-care Blood Gas Analyzers using Local Area Network / 대한진단검사의학회지

BACKGROUND: Point-of-care (POC) testing is expanding because of the many advantages, such as faster turnaround time, immediate decision making and patient management. However, POC testing has problems; poor maintenance and quality control of devices and management of test results. We installed data management system (DMS) for POC blood gas analyzers using local area network for the resolution of those problems. METHODS: We connected nine POC blood gas analyzers Rapidpoint 400 (Bayer Diagnostics Ltd., Newbury, UK) to POC data manager Rapidlink (Bayer Diagnostics Ltd.) by device interface using local area network and developed in-house program for connecting POC data manager to laboratory information system (LIS)/hospital information system (HIS). We surveyed user acceptability and reliability of test results. We examined patterns of problems detected and solved in operating DMS based on quality records. We calculated the change of the yearly test numbers of arterial blood gas analysis (ABGA) after installation of DMS. RESULTS: Test results of POC blood gas analyzers were transferred to LIS and could be checked in HIS. By means of user survey, we judged that the users of POC blood gas analyzers operated the devices with ease and thought test results reliable. POC data manager server implemented in central laboratory enabled remote maintenance and quality control of devices with little workload. POC ABGA test number increased by 3.7 fold during the two years. CONCLUSIONS: We developed DMS for POC blood gas analyzers, enabling test result retrieval and remote maintenance and quality control of devices. This is very informative study for other hospitals installing DMS for POC testing in Korea.

Detection of HBV YMDD Mutation by Sequencing Method / 대한진단검사의학회지

BACKGROUND: YMDD motif variants of the hepatitis B virus (HBV) emerge in some chronic hepatitis B patients after prolonged lamivudine treatment. HBV DNA breakthrough may be accompanied by the emergence of YMDD variants. The detection of YMDD motif variants will be necessary since Adefovir dipivoxil was recently approved to be an effective treatment for lamivudine-resistant patients. METHODS: Samples were chosen from twenty-one patients who experienced the DNA breakthrough after an undetectable HBV DNA period by HBV DNA hybrid-capture assay. We tested the samples of each stage for detection of YMDD motif variants by a sequencing method using Accu-Typer(TM) HBV YMDD typing Kit (DNA Link, Seoul, Korea) and ABI PRISM 3700 DNA Analyzer. RESULTS: All 17 samples that were collected before treatment had the wild-type YMDD motif. Of 20 samples amplified, which were from the undetectable HBV DNA period, three (15%) samples showed YMDD mutation. After DNA breakthrough, YMDD mutants were detected in 13 (63%) of 21 samples (YIDD 8 cases, YVDD 5 cases). CONCLUSION: We could reconfirmed that YMDD motif variants were remarkably related to the lamivudin resistance. YMDD motif variants; however, were not detected in one-third of the lamivudine resistance. The sequencing method of our study would be useful in providing the neighboring nucleotide information other than the YMDD motif in patients experiencing DNA breakthrough.

A Case of Haemophilus aphrophilus Endocarditis / 대한임상미생물학회지

Haemophilus aphrophilus is a facultatively anaerobic gram-negative bacillus and require 5 to 10 % CO2 to grow optimally. H. aphrophilus is differentiated from other members of Haemophilus species by no requirement of X or V factor. This organism is found as the normal flora in upper respiratory tract but a member of the HACEK group that cause native valve endocarditis. Since the first endocarditis of H. aphrophilus was reported at 1985 in Korea, we reported the second case. A 35-year-old male patient was admitted to Asan Medical Center because of fever for 15 days and altered mentality developed 2 days ago. His echocardiography revealed a mitral valve regurgitation with a hypermobile vegetation and multiple septic emboli were also found in the brain MRI. Three sets of blood cultures were taken on the day of admission, all of which grew pleomorphic, gram-negative bacilli at incubation day 1. Catalase and oxidase test was negative and Vitek NHI card (bioMerieux Vitek, Inc., Hazelwood Mo., USA) identified the organisms to H. aphrophilus 50%/H. paraphrophilus 49% (Bionumber 257310). It was finally identified to H. aphrophilus with requirement tests of X or V factors; it required neither X nor V factor. This H. aphrophilus strain was negative inlactamase and was susceptible to ampicillin, gentamicin, cefuroxime, imipenem, ciprofloxacin, aztreonam, azithromycin, rifampin, and trimethoprim/sulfamethoxazole. This patient was successfully treated with ampicillin and gentamicin after mitral valve replacement under diagnosis of H. aphrophilus endocarditis

Genotype Analysis of Hepatitis B Virus Isolated from Korean Hepatitis Patients / 대한진단검사의학회지

BACKGROUND: Hepatitis B virus (HBV) is classified into 7 genotypes (A-G) that have distinct geographic distribution. Several studies have suggested that the HBV genotypic differences influence the severity of liver disease and clinical outcomes such that genotype C is associated with more advanced liver diseases and genotype B is associated with the earlier development of hepatocellular carcinoma. With the different genotypes of HBV reported in Shanghai, Taiwan and Japan, wetried to investigate the distribution of the HBV genotype and the utility of HBV genotyping tests in the Korea population. METHODS: A total of 51 HBV DNA positive serum from Korean hepatitis B patients were used for the genotyping. After PCR and sequencing, HBV genotypes were determined by phylogenetic analysis using the NCBI database (www.ncbi.nlm.nih.gov). RESULTS: By phylogenetic analysis in the Pre-S region, all the genotypes of HBV (100%) proved to be C. CONCLUSIONS: All patients in this study had genotype C. This result is consistent with previous studies reporting 96-100% distribution of genotype C in Korea. HBV genotyping in Korea is not informative in predicting individual variation of clinical outcome, so that it is meaningless to genotype HBV in routine laboratory genotyping.

Genotype Analysis of Hepatitis B Virus Isolated from Korean Hepatitis Patients / 대한진단검사의학회지

BACKGROUND: Hepatitis B virus (HBV) is classified into 7 genotypes (A-G) that have distinct geographic distribution. Several studies have suggested that the HBV genotypic differences influence the severity of liver disease and clinical outcomes such that genotype C is associated with more advanced liver diseases and genotype B is associated with the earlier development of hepatocellular carcinoma. With the different genotypes of HBV reported in Shanghai, Taiwan and Japan, wetried to investigate the distribution of the HBV genotype and the utility of HBV genotyping tests in the Korea population. METHODS: A total of 51 HBV DNA positive serum from Korean hepatitis B patients were used for the genotyping. After PCR and sequencing, HBV genotypes were determined by phylogenetic analysis using the NCBI database (www.ncbi.nlm.nih.gov). RESULTS: By phylogenetic analysis in the Pre-S region, all the genotypes of HBV (100%) proved to be C. CONCLUSIONS: All patients in this study had genotype C. This result is consistent with previous studies reporting 96-100% distribution of genotype C in Korea. HBV genotyping in Korea is not informative in predicting individual variation of clinical outcome, so that it is meaningless to genotype HBV in routine laboratory genotyping.