Sayaka Mori

Heterogeneity in clonal nature in the smoldering subtype of adult T-cell leukemia : continuity from carrier status to smoldering ATL

To better understand indeterminate HTLV-1 carriers and smoldering (SM) subtype of adult T-cell leukemia (ATL), HTLV-1 proviral integrated status, proviral load (PVL) and ATL-related biomarkers were examined in 57 smoldering cases, including unusual carriers with a percentage of ATL-like cells. We found that according to Southern blot hybridization analytic features, 28 patients with SM ATL could be divided into 3 groups consisting of 16 (57.4%) patients with a monoclonal band, 6 (21.4%) with oligoclonal bands and the remaining 6 with smears. Although no clinical differences were observed among the 3 SM subtypes, HTLV-1-infected CD4 T-cell counts increased in order of poly-, oligo- and monoclonal subtypes. This trend began in the carrier stage and also was observed in PVL, CD25 and CCR4, indicating that a clone consisting of leukemic phenotypic cells was continuously growing. Moreover, the antigen modulation rates of CD26 and CD7 and the increasing rate of CD25 and CCR4 cells were closely correlated to growing clonal size, indicating that these markers had the possibility to predict a monoclonal band. In particular, CD26 or the ratio of CD26/CD25 had a validity differential for leukemic nature and predictive detection of clonal band. Conclusively, the present study shows that smoldering ATL is heterogeneous in the leukemogenic process, and the behavior of CD26 plays a central role in the evolution from early occult to overt smoldering ATL.

Paradoxical expression of IL-28B mRNA in peripheral blood in human T-cell leukemia virus Type-1 mono-infection and co-infection with hepatitis C Virus

BackgroundHuman T-cell leukemia virus type-1 (HTLV-1) carriers co-infected with and hepatitis C virus (HCV) have been known to be at higher risk of their related diseases than mono-infected individuals. The recent studies clarified that IL-28B polymorphism rs8099917 is associated with not only the HCV therapeutic response by IFN, but also innate immunity and antiviral activity. The aim of our research was to clarify study whether IL-28B gene polymorphism (rs8099917) is associated with HTLV-1/HCV co-infection.ResultsThe genotyping and viral-serological analysis for 340 individuals showed that IL-28B genotype distribution of rs8099917 SNP did not differ significantly by respective viral infection status. However, the IL-28B mRNA expression level was 3.8 fold higher in HTLV-1 mono-infection than HTLV-1/HCV co-infection. The high expression level was associated with TT (OR, 6.25), whiles the low expression was associated with co-infection of the two viruses (OR, 9.5). However, there was no association between down-regulation and ATL development (OR, 0.8).ConclusionHTLV-1 mono-infection up-regulates the expression of IL-28B transcripts in genotype-dependent manner, whiles HTLV-1/HCV co-infection down-regulates regardless of ATL development.

Rapid, Simple, and Accurate Detection of K-ras Mutations From Body Fluids Using Real-Time PCR and DNA Melting Curve Analysis

The K-ras oncogene is one of the most useful genetic markers in screening for the presence of cancers because it is largely involved in tumorigenesis. However, most mutationdetection techniques are generally unsuitable for routine use, especially due to their timeconsuming, labor-intensive, and sensitive natures. Accordingly, we attempted to establish a new technique for analysis of K-ras alterations at codons 12 and 13 from body fluid specimens with tumor DNA using realtime polymerase chain reaction (PCR) with melting curve analysis (MCA). In this PCRMCA method, K-ras was easily genotyped by melting temperatures (Tm) that differ by 3.6°C to 11.6°C with an acceptable reproducibility of Tm. The shape of the melting curve gave easier interpretation. The detection sensitivity was at least 10 -3 . The entire process of the test was completed within 4 hours, saving 7 to 8 hours when compared to the current PCR-restriction fragment length polymorphism (RFLP) analysis. The examination of the MCA method using 38 clinical samples revealed the better detection rate (32% versus 24%) and diagnostic efficiency (100% versus 92%) compared with that of the PCR-RFLP. In conclusion, this small scale but high throughput method is acceptable for clinical use to analyze K-ras alterations from body fluids and plasma DNA, including small tumor DNA.

Rapid and high-resolution detection of IgH gene rearrangements using PCR and melting curve analysis

The analytical methods of Southern blot hybridization (SBH) and the polymerase chain reaction (PCR) for complementarity determining region‐3 (CDR3) are fundamental for detecting IgH gene rearrangement. However, there are problems stemming from the characteristics of both methods; especially, the long turn around time (TAT) because of the complex process in the SBH, and the low analytical sensitivity for amplicons in the PCR. Thus, to improve the PCR procedure, we investigated the application of detecting the clonal amplicons based on the different melting Temperature (Tm) in internal melting domains corresponding to the CDR3 hypervariable region. Our new protocol is based on the combination of a LightCycler Technology with high‐speed amplification, and Idaho‐Technology with rapid and high‐resolution melting curve analysis (MCA), designated PCR‐MCA. This method can provide the results within 3 h with an analytical sensitivity of 10−3. The diagnostic sensitivity and specificity relative to the results documented with the SBH analysis were 89.2% and 100%, respectively. This indicates that the new protocol of PCR‐MCA is acceptable for clinical testing; especially, PCR‐MCA is relevant in terms of the rapid and sensitive detection of IgH clonality within amplicons.

Suppressor of cytokine signal 3 and IL28 genetic variation predict the viral response to peginterferon and ribavirin.

Aim:  The aim of this study was to investigate the relationship among the expression of suppressor of cytokine signaling 3 (SOCS 3) in the liver, the SNPs in the IL28B locus, and the outcome of interferon therapy.

Molecular analysis of the BCR-ABL1 kinase domain in chronic-phase chronic myelogenous leukemia treated with tyrosine kinase inhibitors in practice: Study by the Nagasaki CML Study Group

An appropriate trigger for BCR-ABL1 mutation analysis has not yet been established in unselected cohorts of chronic-phase chronic myelogenous leukemia patients. We examined 92 patients after 12 months of tyrosine kinase inhibitor (TKI) treatment in Nagasaki Prefecture, Japan. Univariate analysis revealed that significant factors associated with not attaining a major molecular response (MMR) were the presence of the minor BCR-ABL1 fusion gene, a low daily dose of TKI, and the emergence of BCR-ABL1 kinase domain mutations conferring resistance to imatinib. Factors associated with the loss of sustained MMR were a low daily dose of TKI and the emergence of alternatively spliced BCR-ABL1 mRNA with a 35-nucleotide insertion. Taken together, our results suggest that the search for BCR-ABL1 mutations should be initiated if patients have not achieved MMR following 12 months of TKI treatment.

High-resolution melting analysis for a reliable and two-step scanning of mutations in the tyrosine kinase domain of the chimerical bcr-abl gene

For relevant imatinib therapy against Philadelphia (Ph)-positive leukemias, it is essential to monitor mutations in the chimerical bcr-abl tyrosine kinase domain (TKD). However, there is no universally acceptable consensus on how to efficiently identify mutations in the target TKD. Recently, high-resolution melting (HRM) technology was developed, which allows gene scanning using an inexpensive generic heteroduplex-detecting dsDNA-binding dye. This study aimed to validate the introduction of HRM in a practical clinical setting for screening of mutations in sporadic sites of the chimerical bcr-abl TKD. All chimerical and wild-type abl TKD regions selectively amplified were used for HRM assays and direct sequencing. The HRM test had approximately 5–90% detection sensitivity for mutations. In contrast to mixture samples with mutant and wild-type cells, all mutant cell samples had indeterminate melting curves equivalent to those of the wild-type due to formation of only a homodulex. This issue was improved by the addition of exogenous wild-type DNA after PCR. Subsequently, HRM results gave a high accordance rate of 97.8% (44/45 samples) compared to the sequencing data. The discordant results in one appear to be due to unsuccessful amplification. Thus, HRM may be considered to be suitable for reliable scanning of mutations in the chimerical abl TKD in a clinical setting.

Human T‐cell leukemia virus type 1 infection worsens prognosis of hepatitis C virus‐related living donor liver transplantation

Severe and life‐threatening donor‐transmitted human T‐cell leukemia virus type 1 (HTLV‐1) infections after solid organ transplantation have been reported. However, in HTLV‐1‐infected recipients, graft and patient survival were not fully evaluated. A total of 140 patients underwent living donor liver transplantation (LDLT). Of these, 47 of 126 adult recipients showed indications of hepatitis C virus (HCV)‐related liver disease. The HTLV‐1 prevalence rate was 10 of 140 recipients (7.14%) and three of 140 donors (0.02%). In HCV‐related LDLT, graft and patient survival was worsened by HTLV‐1 infection in recipients (seven cases). The 1‐, 3‐, and 5‐year survival rates in the HCV/HTLV‐1‐co‐infected group were 67%, 32%, and 15%, respectively, and the corresponding rates in the HCV‐mono‐infected group were 80%, 67%, and 67%, respectively. Only the 5‐year survival rates were statistically significant (P = 0.04, log‐rank method). HTLV‐1 infection in recipients is also an important factor in predicting survival in HTLV‐1 endemic areas.

Strong influence of human leukocyte antigen-DP variants on response to hepatitis B vaccine in a Japanese population

Genome-wide association studies (GWASs) have reported that human leukocyte antigen (HLA) variants are associated with chronic hepatitis B, spontaneous hepatitis B virus (HBV) clearance, and response to hepatitis B vaccine. Single nucleotide polymorphisms (SNPs) in HLA-DP (rs9277535 and rs3077) and HLA-DQ (rs2856718 and rs7453920) have been repeatedly associated with chronic hepatitis B and spontaneous HBV clearance. However, the data on the SNPs associated with response to hepatitis B vaccine are inconclusive. The objective of this study was to determine whether these four HLA SNPs that have been identified as risk loci for chronic HBV infection are associated with response to hepatitis B vaccine in a Japanese population. We enrolled 278 medical students who received hepatitis B vaccination and measured anti-hepatitis B surface (HBs) antibody titers 1month after a three-dose vaccination series. We found that rs9277535 and rs3077 in HLA-DP were strongly associated with response to hepatitis B vaccine (odds ratio [OR]=0.31 and 0.32, P=0.004 and 0.010, respectively). These two SNPs were significantly associated with anti-HBs titers in an allele-dependent manner. On the other hand, rs2856718 and rs7453920 in HLA-DQ were not associated with response to hepatitis B vaccine. These results indicate that rs9277535 and rs3077 in HLA-DP are the major determinants of response to hepatitis B vaccine, whereas rs2856718 and rs7453920 in HLA-DQ have little effect on the immune response to hepatitis B vaccine.

Simultaneous screening for JAK2 and calreticulin gene mutations in myeloproliferative neoplasms with high resolution melting.

INTRODUCTION Recently, novel calreticulin (CALR) mutations were discovered in Janus kinase 2 (JAK2) non-mutated myelofibrosis (PMF) and essential thrombocythemia (ET) cases, with a frequency of 60-80%. We examined clinical correlations and CALR mutation frequency in our myeloproliferative neoplasms (MPN) cases, and introduce an effective test method for use in clinical practice. METHODS We examined 177 samples previously investigated for the JAK2 mutation for differential diagnosis of MPN. JAK2 and CALR mutations were analyzed using melting curve analysis and microchip electrophoresis, respectively. Next, we constructed a test for simultaneous screening of the JAK2 and CALR mutations utilizing high resolution melting (HRM). RESULTS Among 99 MPN cases, 60 possessed the JAK2 mutation alone. Of the 39 MPN cases without the JAK2 mutation, 14 were positive for the CALR mutation, all of which were ET. Using our novel screening test for the JAK2 and CALR mutations by HRM, the concordance rate of conventional analysis with HRM was 96% for the JAK2 mutation and 95% for the CALR mutation. CONCLUSION Our novel simultaneous screening test for the JAK2 and CALR gene mutations with HRM is useful for diagnosis of MPN.