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ABSTRACT: The early diagnosis of acute hepatitis A (AHA) is hindered because serum IgM against hepatitis A virus (HAV) can yield false-negative results during the window period. This study evaluated the diagnostic accuracy of a polymerase chain reaction (PCR) kit for HAV RNA for the diagnosis of AHA.
Samples were collected from 136 patients with acute severe hepatitis at their admission to Asan Medical Center between June 2010 and July 2010. Samples were analyzed for serum IgM anti-HAV using an immunoassay test and for qualitative HAV RNA using the Magicplex HepaTrio PCR test kit. The diagnostic accuracies of these methods were tested on the basis of clinical and laboratory diagnoses of AHA.
The concordance rate and kappa value between IgM anti-HAV and HAV RNA PCR were 88.2% and 0.707, respectively. For the diagnosis of AHA, the sensitivity and specificity of IgM anti-HAV were 90.7% and 100%, respectively, when an "equivocal" result was regarded as positive; and 79.1% and 100%, respectively, when an "equivocal" result was regarded as negative. The sensitivity and specificity of HAV RNA PCR were 81.4% and 100%, respectively. All four patients with negative IgM anti-HAV and positive HAV RNA PCR results and all four patients with equivocal IgM anti-HAV RNA and positive HAV RNA PCR results were eventually diagnosed with AHA.
The qualitative HAV RNA PCR test has an equivalent diagnostic accuracy for AHA compared to IgM anti-HAV and may be more sensitive during the window period.
Clinical and molecular hepatology. 12/2012; 18(4):397-403.
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ABSTRACT: BACKGROUND: The probability of a prostate cancer-positive biopsy result varies with PSA concentration. Thus, we applied information theory on classification and regression tree (CART) analysis for decision making predicting the probability of a biopsy result at various PSA concentrations. METHODS: From 2007 to 2009, prostate biopsies were performed in 664 referred patients in a tertiary hospital. We created 2 CART models based on the information theory: one for moderate uncertainty (PSA concentration: 2.5-10ng/ml) and the other for high uncertainty (PSA concentration: 10-25ng/ml). RESULTS: The CART model for moderate uncertainty (n=321) had 3 splits based on PSA density (PSAD), hypoechoic nodules, and age and the other CART for high uncertainty (n=160) had 2 splits based on prostate volume and free PSA. In this validation set, the patients (14.3% and 14.0% for moderate and high uncertainty groups, respectively) could avoid unnecessary biopsies without false-negative results. CONCLUSIONS: Using these CART models based on uncertainty information of PSA, the overall reduction in unnecessary prostate biopsies was 14.0-14.3% and CART models were simplified. Using uncertainty of laboratory results from information theoretic approach can provide additional information for decision analysis such as CART.
Clinica chimica acta; international journal of clinical chemistry 10/2012; · 2.54 Impact Factor
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Shin Hwang,
Chul-Soo Ahn,
Gi-Won Song,
Ki-Hun Kim,
Deok-Bog Moon, Heung-Bum Oh,
Young-Suk Lim,
Han Chu Lee,
Tae-Yong Ha,
Dong-Hwan Jung,
Young-Hwa Chung,
Sung-Gyu Lee
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ABSTRACT: A considerable proportion of liver transplantation recipients who receive hepatitis B immunoglobulin (HBIG) monotherapy for hepatitis B virus (HBV) prophylaxis develop resistance to HBIG. We retrospectively assessed the efficacy of HBV prophylaxis in 1524 patients who received primary high-dose HBIG monotherapy (n = 1463) or with a preemptive antiviral add-on as secondary combination therapy (n = 61). At a median follow-up time of 57 months, 106 (7.3%) patients receiving HBIG monotherapy experienced HBV recurrence, with a 10-year HBV recurrence rate of 9.8%, compared to none of the patients receiving preemptive combination therapy (P = 0.047). Thirteen patients (12.3%) with HBV recurrence failed antiviral therapy, leading to death or retransplantation. Response rates to rescue therapy before and after use of adefovir/entecavir were 44.4% and 91.8%, respectively. Acute exacerbation was not associated with treatment failure, but required prolonged treatment. Of 84 surviving patients with HBV recurrence, 44 (52.4%) showed no evidence of blood HBV DNA. The Gly145Arg mutation was found in 11 of 15 (73.3%) patients, whereas 25 of 71 (35.2%), 2 of 29 (6.9%), and 4 of 8 (50%) patients were resistant to lamivudine, adefovir, and entecavir, respectively. In conclusion, our finding of a 10-year HBV recurrence rate of 9.8% in patients receiving high-dose HBIG monotherapy indicates that this treatment is effective but requires complementary measures. Strict surveillance following HBIG monotherapy is necessary to enhance responses to rescue antiviral therapy. Preemptive conversion to combination therapy has a complementary role in prophylaxis with primary high-dose HBIG monotherapy, especially for patients at high risk of HBV recurrence.
Liver Transplantation 04/2011; 17(4):456-65. · 3.39 Impact Factor
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Jun Kang,
Jeong Hyun Cho,
Cheol Won Suh,
Dae Ho Lee, Heung Bum Oh,
Yong Hak Sohn,
Hyun Sook Chi,
Chan Jeong Park,
Sung Soo Jang,
Kyoo Hyung Lee,
Je-Hwan Lee,
Jung Hee Lee,
Sang Wook Lee,
Young Hwa Chung,
Tae Hyup Kim,
Hai-Rim Shin,
Jooryung Huh
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ABSTRACT: We performed a large case-control study (3,932 cases, 15,562 controls) to investigate the association of hepatitis B virus (HBV) and hepatitis C virus (HCV) with hematopoietic malignancies in Korea, where HBV is endemic. HBV was present in 636 control patients (4.1%), 333 lymphoma patients (12.4%), and 75 leukemia patients (6.0%). HCV infection was present in 173 control patients (1.1%), 76 lymphoma patients (2.8%), and 18 leukemia patients (1.4%). Co-infection of HBV and HCV was present in one (0.007%) control patient, seven lymphoma patients (0.3%), and one leukemia patient (0.08%). HBV infection was associated with increased risks for most subtypes of B and T/NK-cell lymphomas, Hodgkin's lymphoma, and acute myeloid leukemia. HCV infection was associated with increased risks for diffuse large B cell lymphoma, extranodal marginal zone B cell lymphoma, peripheral T cell lymphoma, and acute lymphoid leukemia B cell early pre-B type. HBV seems to have a more important role than HCV in the pathogenesis of specific hematologic malignancies in Korea.
Annals of Hematology 02/2011; 90(2):159-64. · 2.62 Impact Factor
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ABSTRACT: Incompatibility of human leukocyte antigen (HLA) alleles between donors and recipients of unrelated hematopoietic stem cell transplantation (UHSCT) increases the risk of acute graft-versus-host disease (GVHD). We evaluated the positional effect of amino acid substitutions in HLA molecules on severe acute GVHD in Korean pediatric recipients of UHSCT. All of 64 donor-recipient pairs were serologically matched for HLA-A, -B, and -DR loci. Only substitution at residue 9 resulting from an HLA-A*02 polymorphism was significantly associated with the risk of severe acute GVHD in patients (OR=7.0, P=0.033) on multivariate analysis. Recipients of this mismatched HLA also showed shortened overall survival (HR=9.7, P<0.001) and increased risk for transplant-related mortality (HR=9.1, P=0.027). Structural modeling showed that the amino acid substitution could alter the peptide preference of the ligand-binding pocket. A single amino acid substitution at position 9 was a major predictor of severe acute GVHD in Korean pediatric patients.
Transplant International 12/2010; 23(12):1216-22. · 2.92 Impact Factor
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ABSTRACT: The prostate-specific antigen (PSA) is considered the most useful among tumor markers currently used. However, its quantitative results are interpreted only qualitatively for the diagnosis of prostate cancer. The recently introduced information theory enables the information of the quantitative results transformed into Shannon's entropy (S) that represents uncertainties and then "1-S" representing diagnostic certainty.
The 882 urological patients enrolled were categorized into 2 groups: a patient group comprising 233 patients with prostate cancer and a disease control group comprising 649 patients with benign prostate disease. The level of PSA in all the patients was tested and was found to be >or=2 ng/mL. The variables like PSA level and age were modeled on logistic regression analysis to predict the probability of prostate cancer and the diagnostic certainty.
The mean (SD) of PSA levels in the patient group and the disease control group were 44.5 ng/mL (37.62 ng/mL) and 5.7 ng/mL (3.70 ng/mL), respectively. The logistic regression model fitted well when the age variable was dichotomized at the age of 55 yr. The diagnostic certainty was lowest at a PSA level of 18.90 ng/mL in the <55-yr age group, and 15.45 ng/mL in the >55-yr age group.
The diagnostic certainty (1-S) of whether to diagnose prostate cancer or not at a certain PSA level could be obtained using the information theory. The methodology used in this study may help interpret the results of other quantitative tests.
The Korean Journal of Laboratory Medicine 08/2010; 30(4):357-63. · 0.63 Impact Factor
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ABSTRACT: The Abbott RealTime hepatitis C virus (HCV) Genotype II (Abbott Molecular Inc.) for HCV genotyping, which uses real-time PCR technology, has recently been developed.
Accuracy and sensitivity of detection were assessed using the HCV RNA PHW202 performance panel (SeraCare Life Sciences). Consistency with restriction fragment mass polymorphism (RFMP) data, cross-reactivity with other viruses, and the ability to detect minor strains in mixtures of genotypes 1 and 2 were evaluated using clinical samples.
All performance panel viruses were correctly genotyped at levels of >500 IU/mL. Results were 100% concordant with RFMP genotypic data (66/66). However, 5% (3/66) of the samples examined displayed probable genotypic cross reactivity. No cross reactivity with other viruses was evident. Minor strains in the mixtures were not effectively distinguished, even at quantities higher than the detection limit.
The Abbott RealTime HCV Genotype II assay was very accurate and yielded results consistent with RFMP data. Although the assay has the advantages of automation and short turnaround time, we suggest that further improvements are necessary before it is used routinely in clinical practice. Efforts are needed to decrease cross reactivity among genotypes and to improve the ability to detect minor genotypes in mixed infections.
Clinical Chemistry and Laboratory Medicine 04/2010; 48(4):469-74. · 2.15 Impact Factor
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ABSTRACT: The hepatitis C virus (HCV) genotype is the most important factor in predicting the outcome of chronic hepatitis C treatment. Therefore, convenient and accurate HCV genotyping methods for routine laboratory testing are needed. In this study, to identify the HCV genotypes, an oligonucleotide DNA chip was designed using 15 probes from the 5'-untranslated region. Reverse transcription was combined with asymmetric polymerase chain reaction (PCR) to obtain an amplified product for hybridization without the need for a denaturation step. In addition, a biotin-labeled PCR product and streptavidin-Cy3 conjugate were cohybridized simultaneously. Clinical sera from Korean and French patients (n=112) were used to compare the chip results with those obtained by direct sequencing. The DNA chip showed 100% accuracy for the commercial panels and had a lower detection limit of 2.8x10(2) IU/ml. Agreement levels between the chip and sequencing results at the genotype and subgenotype levels were 100% and 94.6% (106/112), respectively. By the combined reverse transcription-asymmetric PCR and cohybridization methods, the DNA chip reduced assay time and was convenient to use. This DNA chip may be useful for identifying HCV genotypes in clinical laboratories.
Journal of virological methods 10/2009; 163(2):269-75. · 2.13 Impact Factor
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ABSTRACT: Many immunochromatography (ICA) kits for anti-human immunodeficiency virus type (HIV) antibody (Ab) have been introduced to improve the accessibility of HIV Ab tests. However, qualified evaluation reports for HIV rapid tests are not enough to validate their performances. Meta-analysis for the performances of the HIV Ab rapid tests was performed in this study.
PubMed database was searched with combination of search terms, 'human immunodeficiency virus', 'HIV Ab', 'rapid test', 'immunochromatography', 'performance', 'sensitivity', and 'specificity'. Criteria of inclusion were performance studies for HIV ICA kits with serum or EDTA whole blood. Methodological qualities were evaluated with standards for reporting of diagnostic accuracy studies (STARD) checklists by two investigators. Homogeneity among selected studies was evaluated and then pooled sensitivity and specificity were calculated. Positive and negative predictive values were simulated with presumed HIV prevalence in Korea.
Twenty-three studies were selected from 12 high-qualified papers with STARD checklists. The performance of 23 studies were found to be heterogeneous (P<0.1) and random effect model was used. Pooled sensitivity was 99.71% (95% CI: 99.45-99.97%) and pooled specificity was 99.27% (95% CI: 98.83-99.70%). With HIV prevalence of 0.03%, positive and negative predictive values were presumed to be 3.936% and 99.999%, respectively.
This meta-analysis for HIV ICA rapid tests showed good performance. In consideration of low positive predictive values of HIV rapid tests, confirmation by enzyme immunoassay or Western blot is still needed. This study would be helpful in evaluating and establishing proper performance guideline for those kits not fully evaluated.
The Korean Journal of Laboratory Medicine 08/2009; 29(4):345-52. · 0.63 Impact Factor
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ABSTRACT: We investigated hepatitis B virus (HBV) infection cases, who were HBsAg negative by radioimmunoassay (RIA) and HBV DNA positive for their clinical characteristics, the S gene mutation of hepatitis B virus (HBV), and usefulness of other HBsAg immunoassay.
Among the patients requested for HBV DNA quantification, 16 patients positive in HBV DNA but negative in HBsAg RIA (BNIBT HBsAg Kit, China) were enrolled. The "a" determinant of HBV S gene was sequenced and clinical characteristics were reviewed. Additional HBsAg assay was performed using Architect HBsAg kit (Abbott laboratories, USA) employing chemiluminescent immunoassay method.
Eleven of the 16 patients showed multiple mutations in the "a" determinant. These patients received liver transplantation several years ago and have been treated with hepatitis B immune globulin (HBIG) and antiviral drugs. G145R mutation was found in 8 patients and G145K, D144G, and D144A were also frequently found. Among 9 of the 11 patients tested for HBsAg by Architect HBsAg kit, 8 showed positive results. Among 4 of the remaining 5 patients, only 2 showed weak positive results (< or = 1 IU/mL) in Architect HBsAg kit.
HBV DNA-positive/HBsAg RIA-negative results were mostly observed in the patients treated with HBIG after liver transplantation, in whom HBIG escape mutations were found. Majority of these cases were positive in Architect HBsAg assay, and it is recommended to use other HBsAg immunoassay methods that are more sensitive than RIA in the detection limit as well as in the detection of escape mutant in hospitals performing liver transplantation.
The Korean Journal of Laboratory Medicine 07/2009; 29(3):224-30. · 0.63 Impact Factor
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ABSTRACT: 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.
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.
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.
It was found that HBV detected in Korean CHB patients under treatment almost all belong to the C2 (Ce) genotype.
The Korean Journal of Laboratory Medicine 03/2009; 29(1):53-8. · 0.63 Impact Factor
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JDCTA. 01/2009; 3:111-119.
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ABSTRACT: Previous surveys of the prevalence of hepatitis C virus (HCV) in Korea have identified types 1 and 2, but little has been said of other genotypes and viral subtypes. In this study, HCV genotypes in Korea were investigated using Restriction Fragment Mass Polymorphism (RFMP) assay, a sensitive and specific method for genotyping based on MALDI-TOF mass spectrometry. A total of 1,043 independent serum samples from HCV-infected patients were analyzed. Of interest, 15 subjects (1.4%) were determined to contain HCV genotype 6 and 46 subjects (4.4%) contained mixed genotypes with the most prevalent genotypes being HCV 1b and 2a/c (45.0% and 35.4%, respectively). The 15 subjects with HCV genotype 6 comprised eight cases of subtype 6c, including one case of mixed infection with 1b, three cases of HCV 6a, and six cases of unassigned subtypes. Sequencing corroborated the identity of genotype 6 from 13 subjects, while the line probe assay (LiPA) mis-identified them as genotype 1b. The majority (7/9) of the genotype 6 patients enrolled for interferon/ribavirin therapy, achieved a sustained virologic response. The ability of the RFMP assay to differentiate various HCV genotypes should enable better analysis of the relationship between HCV genotype and disease prognosis.
Journal of Medical Virology 11/2008; 80(10):1712-9. · 2.82 Impact Factor
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ABSTRACT: 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.
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).
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.
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.
The Korean Journal of Laboratory Medicine 11/2008; 28(5):362-70. · 0.63 Impact Factor
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ABSTRACT: Although hepatitis B surface antigen (HBsAg) rapid test based on immunochromatographic assay (ICA) is now widely used, the test has not been evaluated sufficiently enough to validate its performance. Thus, it is important to summarize the clinical performance of the test kits. In this study, we performed meta-analysis for the performance of the HBsAg rapid tests.
PubMed database was searched using keywords about the accuracy of diagnostic tests for hepatitis B virus (HBV) infection. Two investigators assessed methodological quality utilizing standards for reporting of diagnostic accuracy studies (STARD) checklist. After performing a heterogeneity test, we obtained pooled sensitivity and specificity. Positive and negative predictive values (PPV and NPV) were simulated according to HBV prevalence.
A total of 38 studies was selected from 10 papers. The quality scores ranged from 3 to 13 (median, 8). Kappa value was good (0.85). The performance of the 38 studies was heterogeneous. When 33 studies with better quality from 7 papers were re-selected, the pooled sensitivity and specificity were 98.07% (95% confidence interval, CI: 97.67-98.47%) and 99.56% (95% CI: 99.21-99.91%), respectively. With an HBV prevalence of 5%, PPV and NPV were predicted to be 92.14% and 99.90%, respectively.
In view of high HBV prevalence in Korea, it is thought that the HBsAg rapid test can be used for HBV screening in small-sized laboratories or for epidemiologic studies. This study should be helpful in establishing a guideline for the proper performance evaluation of the HBsAg rapid tests.
The Korean Journal of Laboratory Medicine 05/2008; 28(2):160-8. · 0.63 Impact Factor
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ABSTRACT: 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).
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).
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 (r(2)=0.9609) and the test results for the BBI panel were also well agreed to the assigned values (r(2)=0.9933).
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.
The Korean Journal of Laboratory Medicine 05/2008; 28(2):144-50. · 0.63 Impact Factor
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ABSTRACT: Mutations in the YMDD motif of the hepatitis B virus (HBV) polymerase gene increase lamivudine resistance of HBV, highlighting the clinical importance of accurate and sensitive detection of HBV mutants. Using dual-priming oligonucleotide primer technology, an assay that can detect mutations at codons 180 (L528M) and 204 (YVDD, YIDD, and YSDD) by a single-step multiplex PCR was developed. This Seeplex Lami-DR assay was sufficiently sensitive to detect 10(3)HBV/ml and was able to detect minor mutants comprising as little as 2% of the viral population. Mutants were detected in 57 of 65 serum samples (88%) from patients with chronic hepatitis B who had been treated with lamivudine (median, 32 months; range, 1-83 months). The agreement with direct sequencing was only 38.5% (25/65). Discrepancies between these methods resulted from detection of additional mutants by the Seeplex Lami-DR assay, as confirmed by a novel verification analysis. This assay is not only highly accurate and sensitive, but is also simple and cost-effective, requiring no expensive probes, laborious sequencing procedures, or digestion with restriction enzymes. Accordingly, the Seeplex HBV Lami-DR assay should be considered as a first-line, cost-effective tool for detecting viral mutations in patients with chronic hepatitis B receiving lamivudine therapy.
Journal of Virological Methods 05/2008; 149(1):76-84. · 2.01 Impact Factor
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ABSTRACT: 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.
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.
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%.
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.
The Korean Journal of Laboratory Medicine 03/2008; 28(1):79-87. · 0.63 Impact Factor
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ABSTRACT: Several machine learning algorithms have recently been applied to modeling the specificity of HIV-1 protease. The problem is challenging because of the three issues as follows: (1) datasets with high dimensionality and small number of samples could misguide classification modeling and its interpretation; (2) symbolic interpretation is desirable because it provides us insight to the specificity in the form of human-understandable rules, and thus helps us to design effective HIV inhibitors; (3) the interpretation should take into account complexity or dependency between positions in sequences. Therefore, it is necessary to investigate multivariate and feature-selective methods to model the specificity and to extract rules from the model. We have tested extensively various machine learning methods, and we have found that the combination of neural networks and decompositional approach can generate a set of effective rules. By validation to experimental results for the HIV-1 protease, the specificity rules outperform the ones generated by frequency-based, univariate or black-box methods.
Computational Biology and Chemistry 03/2008; 32(1):71-8. · 1.55 Impact Factor
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ABSTRACT: Although autoimmune pancreatitis (AIP) responds well to corticosteroid therapy, relapse during maintenance corticosteroid therapy or after the withdrawal of corticosteroid treatment is not uncommon. To date, the factors related to relapse of AIP have not been fully explored.
To determine the clinical and genetic predictors relating to the relapse of AIP, we evaluated clinical factors, HLA polymorphisms, and the amino acid sequences in 40 patients with AIP.
At a median follow-up period of 40 months (range, 12-67 months), relapse developed in 13 of 40 patients with AIP (33%), in whom complete remission was achieved with oral corticosteroid therapy. Among demographics, clinical characteristics in the initial diagnosis of AIP, we could not find any clinical predictor for relapse of AIP; however, in amino acid sequence analysis for relapse of AIP, the substitution of aspartic acid to nonaspartic acid at residue 57 of DQbeta1 showed a significant association with relapse of AIP (nonrelapse group, 29.6%; relapse group, 100%; P = .00003; odds ratio, 3.38; 95% confidence interval, 1.9-6.0). There was a significant difference in the timing of relapse of AIP, according to density of the nonaspartic acid residue at DQbeta1 57 (nonaspartic acid homozygosity: mean +/- SD, 6.7 +/- 4.2 months; nonaspartic acid heterozygosity: mean +/- SD, 33 +/- 11 months; P < .001).
Substitution of aspartic acid to nonaspartic acid at DQbeta1 57 appears to represent a key genetic factor for relapse of AIP (ClinicalTrials.gov number, NCT00444444).
Gastroenterology 03/2008; 134(2):440-6. · 11.68 Impact Factor
