The impact of cytogenetic abnormalities on the prognosis of primary myelofibrosis: a prospective survey of 202 cases in Japan.

Cytogenetic abnormalities were often observed in primary myelofibrosis patients. The presence of specific cytogenetic abnormalities, such as sole abnormalities of chromosome 13q-, 20q-, or -7/7q-, is reported to have the influence on the prognosis of primary myelofibrosis. We analyzed the data from the prospective survey of Japanese primary myelofibrosis patients which was conducted from 1999 to clarify the impact of cytogenetic abnormalities on the prognosis of primary myelofibrosis. A total of 202 primary myelofibrosis patients had the cytogenetic and the prognostic data. Eighty (40%) out of 202 cases had cytogenetic abnormalities, and an association was evident for platelet counts. Although the presence of an abnormal karyotype did not affect the prognosis, primary myelofibrosis patients with cytogenetic abnormalities other than 13q- and 20q- showed an inferior prognosis compared to patients with a normal karyotype or sole 13q- or 20q- abnormalities. Patients with an unfavorable cytogenetic profile (abnormal cytogenetics other than 13q- or 20q-) also had a greater tendency to transform to leukemia than patients with a favorable cytogenetic profile (normal cytogenetics, sole abnormalities of either chromosome 13q-, or 20q-). Abnormal cytogenetics other than 13q- or 20q- in primary myelofibrosis patients has the poor prognostic effect for both survival and the risk of leukemic transformation.

Roles of DRB1 *1501 and DRB1 *1502 in the pathogenesis of aplastic anemia.

OBJECTIVE: Although a number of reports have documented a significantly increased incidence of HLA-DR15 in aplastic anemia (AA), the exact role of HLA-DR15 in the immune mechanisms of AA remains unclear. We herein clarify the difference between DRB1( *)1501 and DRB1( *)1502, the two DRB1 alleles that determine the presentation of HLA-DR15, in the pathophysiology of AA. MATERIALS AND METHODS: We investigated the relationships of the patients( *) HLA-DRB1 allele with both the presence of a small population of CD55(-)CD59(-) (PNH-type) blood cells and the response to antithymocyte globulin (ATG) plus cyclosporin (CsA) therapy in 140 Japanese AA patients. RESULTS: Of the 30 different DRB1 alleles, only DRB1( *)1501 (33.6% vs 12.8%, p(c) < 0.01) and DRB1( *)1502 (43.6% vs 24.4%, p(c) < 0.01) displayed significantly higher frequencies among the AA patients than among a control. AA patients possessing HLA-DR15 tended to be old, and especially, the frequency of DRB1( *)1502 in patients 40 years of age and older (52.4%) was markedly higher than that in those younger than 40 years old (16.2%, p(c) < 0.01). Only DRB1( *)1501 was significantly associated with the presence of a small population of PNH-type cells and it also showed a good response to ATG plus CsA therapy in a univariate analysis. A multivariate analysis showed only the presence of a small population of PNH-type cells to be a significant factor associated with a good response to the immunosuppressive therapy (p < 0.01). CONCLUSIONS: Although both DRB1( *)1501 and DRB1( *)1502 contribute to the development of AA, the methods of contribution differ between the two alleles.

A multicenter randomized, double-blind, placebo-controlled late-phase II/III study of recombinant human interleukin 11 in acute myelogenous leukemia.

To investigate the efficacy of using recombinant human interleukin 11 (rhIL-11) to reduce the need for platelet transfusions, we performed a randomized, double-blind phase II/III study with 110 acute myelogenous leukemia (AML) patients in the first complete remission. Following chemotherapy patients were subcutaneously administered either placebo (n=37) or rhIL-11 at a dose of 25 microg/kg (n=37) or 50 microg/kg (n=36). rhIL-11 administration was well tolerated. There was no difference between the rhIL-11 and placebo groups in the frequency and volume of platelet transfusions. In a perprotocol analysis set (101 patients), the platelet transfusion frequency in the 50-microg/kg group (3.0 +/- 1.76 times) was significantly lower than in the placebo group (3.9 +/-2.35 times; multiplicity-adjusted P= .049). We analyzed infection-related events retrospectively. The frequency of fever was significantly decreased in the 50-microg/kg, 25-microg/kg, and placebo groups (66.7%, 70.3%, and 89.2%, respectively; P= .018, Cochran-Armitage test). Stomatitis was less frequent in the 50-microg/kg and 25-microg/kg groups (2.8% and 0%, respectively) than in the placebo group (21.6%, P= .0012). These results show that rhIL-11 does not reduce the platelet transfusion requirement in AML patients, but the retrospective analysis confirms the previous finding that rhIL-11 reduces infection in patients undergoing chemotherapy.

The effect of anabolic steroids on anemia in myelofibrosis with myeloid metaplasia: retrospective analysis of 39 patients in Japan.

Between 1999 and 2005, 285 patients received new diagnoses of myelofibrosis with myeloid metaplasia (MMM) in Japan. Anemic symptoms were present in 162 patients, and hemoglobin (Hb) concentrations were <10 g/dL in 197 patients. Fifty-five MMM patients were treated with anabolic steroids, and their effect on anemia during MMM was evaluated in 39 patients. A "good" response was defined as an Hb increase of >or=1.5 g/dL, cessation of transfusion dependence, and an Hb concentration of >10 g/dL maintained for at least 8 weeks. A "minimum" response was defined as an Hb increase of >or=1.5 g/dL and transfusion independence for at least 8 weeks. Both good and minimum responses were considered "favorable." Favorable responses were achieved in 17 patients (44%, 8 good and 9 minimum responses). None of the pretreatment variables, such as the lack of transfusion dependence, a higher Hb concentration at the start of treatment, or the absence of cytogenetic abnormalities, were associated with a response to anabolic steroid therapy. Adverse events associated with anabolic steroid therapy were moderate and transient. Two patients required definitive withdrawal of treatment. Thus, anabolic steroids are well tolerated and effective for the treatment of anemia in a subset of MMM patients.

Assessment of the international prognostic scoring system for determining chemotherapeutic indications in myelodysplastic syndrome: Japanese retrospective multicenter study.

To standardize a rational therapeutic strategy of chemotherapy using the International Prognostic Scoring System (IPSS), we retrospectively analyzed 292 high-risk myelodysplastic syndrome (MDS) patients in 20 hospitals in Japan. Results of multivariate analysis of the data on patients who received all types of chemotherapy indicated that poor cytogenetics as shown by the IPSS was the only significant risk factor (P = .047). We then focused on the IPSS composition of each patient. The intermediate 2 (Int-2) category consisted of a heterogeneous group. We attempted to subdivide the category into Int-2A and Int-2B. Patients with good or intermediate cytogenetics had > or = 5% bone marrow (BM) blasts (Int-2A), and most of the other patients had poor cytogenetics and < or = 10% BM blasts (Int-2B). In the Int-2B category, overall survival for patients who received chemotherapy was significantly worse than for those who did not receive chemotherapy (P = .005). Most patients in the High category who had the diagnosis of MDS according to the World Health Organization classification had poor overall survival with or without chemotherapy. We propose the Int-2B and High categories may be considered possible high risk, whereas all patients in the Int-2A category and patients with more than 5% BM blasts in the Int-1 category may be categorized as being at possible intermediate risk. Our proposition may be useful for developing a chemotherapeutic strategy for patients with MDS in Japan.

Long-term results of a multicenter randomized, comparative trial of modified CHOP versus THP-COP versus THP-COPE regimens in elderly patients with non-Hodgkin's lymphoma.

In treating elderly non-Hodgkin's lymphoma (NHL) patients, it is particularly important to use drugs that have a low incidence of adverse events and high efficacy. In this multicenter study, THP (pirarubicin)-COP (cyclophosphamide, vincristine, and prednisolone) was compared to two thirds dosage of full CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisolone) regimen with regard to both adverse events and efficacy. For a third group, etoposide (E) was added to the THP-COP regimen (THP-COPE) in order to achieve high dose-intensity. Subjects were 486 previously untreated patients, aged 65 or older (range, 65-92 years; median, 74 years), with NHL. Subjects were randomly assigned to receive THP-COP, two thirds CHOP, or THP-COPE. Four hundred and forty-three patients were assessed for response and followed for 8 years after the last subject registered. The complete remission rates for the THP-COP, CHOP, and THP-COPE groups were 42.5%, 41.4%, and 48.0%, respectively. There was no difference in overall survival or progression-free survival among these 3 groups. In aggressive lymphoma, there was also no difference in complete response (CR) rate (45.3% in THP-COP, 44.9% in CHOP, 48.0% in THP-COPE), overall survival, and progression-free survival among these groups. The 5- and 8-year survival rates for all patients were 29.4% and 18.7%, respectively. The 5- and 8-year survival rates for patients with aggressive lymphoma were 27.4% and 17.4%, respectively. Although long-term survival for patients with aggressive lymphoma on our regimens was not worse compared to previous reports, the CR rate was lower. Because severe adverse events were not observed, higher dose chemotherapy may be directed to achieve better CR rates. In patients with T-cell-type lymphoma, the CR rate was greater after treatment with THP-COP (51.4%) or THP-COPE (57.7%) compared to treatment with CHOP (19.4%). Pirarubicin may be more useful for T-cell lymphoma than doxorubicin. Because adverse cardiac events were reported only in CHOP, adverse cardiac events might be low in the THP group.

[Clinical course of the disease and the level of WT1 mRNA in 191 patients with acute myeloid leukemia (AML): joint research by 23 institutions in Japan].

We evaluated the clinical course of acute myeloid leukemia (AML) and the levels of WT1 mRNA in 191 AML patients. Of 114 previously untreated patients with AML, 107 cases were positive for WT1 mRNA (93.9% : 107/114). WT1 mRNA expression-levels declined to below 50 copies/microg RNA ("negative") after remission was achieved in all 66 patients who achieved remission and 84.8% (47/54) cases were "negative" at the end of the follow-up periods. On the other hand, WT1 mRNA was expressed in 87.0% of non-remission cases (47/54), maintaining 50 copies/microg of RNA or higher ("positive"). In all 29 cases who relapsed during the follow-up observation period after achieving remission, WT1 mRNA levels declined transiently approximately around the time of achieving remission and then rose again when the disease relapsed. Moreover, we determined the time of elevation of WT1 mRNA in 29 relapsed cases. In 79.3% of relapsed cases (23/29), WT1 mRNA levels rose above 200 copies/microg RNA, 43 days (median) before the diagnosis of "relapse". Given the percent of the correct diagnosis, WT1 mRNA at 200 copies/microg RNA appeared to be a reasonable cut-off level for early detection of AML-relapse. The WT1 mRNA level reflected the clinical condition. Taken together, these findings indicate that WT1 mRNA levels allow us to detect the presence of so-called "minimal residual disease" (leukemic cells) that cannot be detected by morphological examination. Besides these promising data, this kit is suitable for routine monitoring of AML because this kit utilizes peripheral blood as a test specimen, reducing the patient's burden at the time of collection of clinical samples as compared with bone marrow aspirate.

Clinical course and flow cytometric analysis of paroxysmal nocturnal hemoglobinuria in the United States and Japan.

: To determine and directly compare the clinical course of white and Asian patients with paroxysmal nocturnal hemoglobinuria (PNH), data were collected for epidemiologic analysis on 176 patients from Duke University and 209 patients from Japan. White patients were younger with significantly more classical symptoms of PNH including thrombosis, hemoglobinuria, and infection, while Asian patients were older with more marrow aplasia. The mean fraction of CD59-negative polymorphonuclear cells (PMN) at initial analysis was higher among Duke patients than Japanese patients. In both cohorts, however, a larger PNH clone was associated with classical PNH symptoms, while a smaller PNH clone was associated with marrow aplasia. Thrombosis was significantly more prevalent in white patients than Asian patients, and was associated with a significantly higher proportion of CD59-negative PMN. For individual patients, CD59-negative populations varied considerably over time, but a decreasing PNH clone portended hematopoietic failure. Survival analysis revealed a similar death rate in each group, although causes of death were different and significantly more Duke patients died from thrombosis. Japanese patients had a longer mean survival time (32.1 yr vs. 19.4 yr), although Kaplan-Meier survival curves were not significantly different. Poor survival in both groups was associated with age over 50 years, severe leukopenia/neutropenia at diagnosis, and severe infection as a complication; additionally, thrombosis at diagnosis or follow-up for Duke patients and renal failure for Japanese patients were poor prognostic factors. These data identify important differences between white and Asian patients with PNH. Identification of prognostic factors will help the design of prospective clinical trials for PNH.

Anti-proliferative effect of the abl tyrosine kinase inhibitor STI571 on the P-glycoprotein positive K562/ADM cell line.

STI571, an abl tyrosine kinase inhibitor, is less effective in chronic myelogenous leukemia (CML) patients in the accelerated phase and in blastic crisis. We addressed whether STI571 is effective for the CML blastic crisis cell line K562 and the P-glycoprotein (P-gp) positive, multidrug resistance cell line K562/ADM. The present results demonstrate that P-gp positive K562/ADM cells were more resistant than K562 cells to the anti-proliferative and apoptotic effect of STI571, but the co-addition of a P-gp modulator augmented the sensitivity of K562/ADM cells to STI571. For patients in CML blastic crisis, simultaneous use of a P-gp modulator may increase the efficacy of STI571.

Telomerase overexpression in K562 leukemia cells protects against apoptosis by serum deprivation and double-stranded DNA break inducing agents, but not against DNA synthesis inhibitors.

Telomeres are specialized DNA/protein structures that act as protective caps to prevent end fusions. The maintenance of telomeres is essential for chromosomal stability. Telomerase is regulated by human telomerase reverse transcriptase (hTERT). c-Myc oncoprotein is also implicated in the positive regulation of hTERT expression. We show here that two clones of hTERT-transfected K562 erythroleukemia cells have elongated telomeres (22.5 and 24.0 kb), whereas telomere length of both c-Myc-transfected K562 cells and parental K562 cells is 6.5 kb. Telomerase activity and hTERT mRNA expression increased in hTERT-transfected K562 cells, while the expression levels of telomerase activity and hTERT in c-Myc-transfected K562 cells were similar to that in parental K562 cells, despite an overexpression of c-Myc. Importantly, we found that hTERT-transfected K562 cells are protected against apoptosis induced by serum deprivation and double-stranded DNA break inducing agents (ionizing irradiation, and etoposide (VP-16)), but not against DNA synthesis inhibitors (1-beta-D-arabinofuranosylcytosine and hydroxyurea). These findings suggest that overexpression of telomerase by transfecting hTERT confers telomere-elongation and resistance to double-stranded DNA break inducing agents.

Cyclosporin A therapy for patients with myelodysplastic syndrome: multicenter pilot studies in Japan.

We examined the efficacy of cyclosporin A (CsA) in 50 patients with myelodysplastic syndrome (MDS) consisting from 47 of RA, 1 of RARS, and 2 of RAEB. These patients showed various marrow cell types including hypo-, normo-, and hypercellularity. Patients belonged to the following International Prognostic Scoring System (IPSS) risk groups: 4 of low, 41 of intermediate-1, and 5 of intermediate-2. The median CsA dose was 4.58mg/kg, and treatment responses were classified according to the International Working Group (IWG) criteria. Hematological improvement (HI) was observed in 30 (60%) patients, and all of them were belonged to RA. In the patients with RARS or RAEB, no efficacy was observed. Four (8%) of the responders achieved partial remission (PR) with granulocytes > or = 1500microl(-1), Hb>11g/dl and platelets > or = 100,000microl(-1). Higher response rate (53%) was shown in erythroid lineage (HI-E) compared to platelet (HI-P, 36%) or neutrophil lineage (HI-N, 35%). When we analyzed the correlation between the response to CsA therapy and the karyotype or HLA type, there were significantly more responders with good karyotype or DRB1*1501 than with intermediate/poor karyotypes or with other HLA types. These results indicate the usefulness of CsA therapy for MDS patients with any marrow cellularity, especially for erythroid lineage and patients with good karyotype or DRB1*1501.

Absence of R24C mutation of the CDK4 gene in leukemias and solid tumors.

A mutation of the p16(INK4a)-binding domain of the cyclin dependent kinase 4 (CDK4) gene, R24C, has been reported in some cases of melanoma. This mutation prevented binding of the CDK4 inhibitor p16(INK48) to CDK4. To determine the relevance of the mutation, we performed polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) analysis in diverse types of human leukemias and solid tumors. No mobility shifts indicating sequence alterations were observed in 273 tumors and 49 cell lines from diverse kinds of tumors These results suggest that in contrast to melanoma, in many other types of human neoplasms the mutation of the CDK4 gene is very rare. To better understand these findings, we randomly mutagenized the CDK4 gene and used the yeast two-hybrid method to screen for CDK4 mutants that had lost the ability to bind to p16(INK4a). Sequence analysis and in vitro kinase assays showed that most of the mutations that disrupted interactions with p16(INK4) also knocked out the activity of CDK4. This result may explain the rareness of CDK4 mutations in human tumors.

Nationwide study of idiopathic thrombocytopenic purpura in pregnant women and the clinical influence on neonates.

Idiopathic thrombocytopenic purpura (ITP) occurs more commonly in young women during the reproductive years. To obtain information for management of ITP in pregnancy, we performed a nationwide retrospective survey. Findings from a total of 284 pregnant women with ITP and their 286 newborn infants were available for analysis. The bleeding tendency at delivery was managed chiefly with corticosteroid, intravenous high-dose gamma-globulin, and platelet transfusion. Maternal complications occurred in 77 cases (27.1%) and were frequently seen in cases with poor control of ITP. Neonatal abnormalities, which were not influenced by the clinical state of the mother, occurred at a frequency of 17.8%. Thrombocytopenia in neonates occurred in 48 cases (22.4%), and bleeding tendency was found in 16 cases (6.3%) without severe bleeding. Prediction of thrombocytopenia in neonates was difficult. However, infants from splenectomized mothers with well-controlled ITP showed thrombocytopenia more frequently than those from nonsplenectomized mothers. Mothers treated with steroids at doses greater than 15 mg/day showed a high frequency of maternal complications and fetal abnormal body weight. These observations will be useful in the management of pregnant women with ITP and their infants.

Multicenter prospective study of clonal complications in adult aplastic anemia patients following recombinant human granulocyte colony-stimulating factor (lenograstim) administration.

To elucidate the relationship between treatment with granulocyte colony-stimulating factor (G-CSF) and the development of chromosomal abnormalities and clonal evolution in adult aplastic anemia (AA) patients, we performed a prospective multicenter study. Of the 104 registered patients, 91 were found by the central review committee to have the diagnosis of AA. Of the 91 patients, 84 were determined to be evaluable in this study and were treated with regimens including G-CSF (lenograstim). A time-course study (at registration and 6 and 12 months after registration) of G-banded chromosomes, fluorescence in situ hybridization (FISH) analysis for monosomy 7, and morphological assessment of bone marrow was performed with these patients during the 1-year follow-up period. G-banding analysis demonstrated the development of cytogenetic abnormalities in 10 (16.1%) of the 62 evaluable patients. The most common aberration was monosomy 7. FISH analysis demonstrated monosomy 7 in 7 (10.4%) of the 67 evaluable patients. Evolution into myelodysplastic syndrome (MDS) was observed in 5 (7.7%) of the 65 patients who underwent morphological assessment of bone marrow. All patients who developed cytogenetic abnormalities or MDS received immunosuppressive agents and/or steroids with G-CSF. This study demonstrated that some adult AA patients exhibit evolution into MDS and development of chromosomal abnormalities such as monosomy 7. Although the incidence seems to be comparable with that found in previous studies, further long-term follow-up will be necessary to confirm the relationship between G-CSF and the development of chromosomal abnormalities and MDS.

Efficacy and safety of imatinib mesylate for patients in the first chronic phase of chronic myeloid leukemia: results of a Japanese phase II clinical study.

Imatinib mesylate is a relatively new drug that targets the BCR-ABL chimeric protein, the molecular basis of chronic myeloid leukemia (CML). A phase II clinical trial in 39 Japanese patients in the first chronic phase of CML was conducted with imatinib mesylate at a dose of 400 mg/day. Hematologic complete response was obtained in 92.3% of the patients, complete cytogenetic response (CR) was obtained in 43.6%, and major partial CR was obtained in 20.5% of the patients. Although 29 of 39 patients required an adjustment of dosing because of grade 3 or 4 adverse events, most of the events were reversible, and 25 of the 29 patients were able to resume therapy. Between day 15 and day 35, grade 3 or 4 neutropenia and/or leukocytopenia occurred in 13 patients, and grade 3 thrombocytopenia occurred in 5 patients. Overall, nonhematologic grade 3 adverse events occurred in 28.2% of the patients. These data support the use of imatinib mesylate as the treatment of choice for chronic-phase CML patients.

[Severe falciparum malaria with prolonged hemolytic anemia after successful treatment with intravenous artesunate].

We report a 68-year-old woman with severe falciparum malaria contracted in Tanzania. She presented high parasitemia and was treated successfully with intravenous artesunate, a qinghaosu derivative, and aggressive supportive therapy. She developed hemolytic anemia and jaundice on day 11 and blood transfusion was required. This case illustrates that intravenous artesunate has excellent antimalarial activity with rapid efficacy and that no severe adverse effect but conventional aggressive supportive therapy is still important in the treatment of severe falciparum malaria.

Increased thymocyte CD4+CD8+ cells and T-cell receptor beta gene rearrangements in thymoma.

Epithelial cells in thymoma and thymic carcinoma may influence T-cell development in the tumor. In this study, we investigated the cell surface phenotype and T-cell receptor (TCR) gene rearrangement of thymocytes in thymic tumors. TCR rearrangement was observed in all cases of thymoma (A, AB, B1-2). A faint band in each digestion suggested the deletion between D1 to C1 or D1 to J2, and an additional rearrangement band with BamHI suggested the rearrangement between D1 to J1. High percentages of CD1+ cells and CD4+CD8+ (DP) cells were detected in all cases of thymoma (A, AB, B1-2). There are two kinds of cell surface phenotypes increased in populations of thymoma; one is increased DP cells and the other is a relatively low percentage of DP cells accompanied by a relatively high percentage of CD3+CD69+ cells. These findings suggest that thymocytes in thymoma are derived from immature T-cell expansion.

[Massive hemolysis following allogeneic peripheral blood stem cell transplantation with minor ABO incompatibility].

We observed massive hemolysis after allogeneic peripheral blood stem cell transplantation with minor ABO incompatibility (the donor was group O and the recipient group A). The patient was a 21-year-old man diagnosed as having Philadelphia chromosome-positive chronic myelogenous leukemia. On day 7 post-transplant, there was abrupt onset of massive hemolysis necessitating supportive treatment with transfusions. During the allogeneic peripheral blood stem cell transplantation the patient had received 2 x 10(8) CD3 positive cells/kg and 7.8 x 10(7) CD19 positive cells/kg donor lymphocytes with stem cells. The present case shows that in allogeneic peripheral blood stem cell transplantation with ABO incompatibility, severe hemolysis occurs early after transplantation presumably due to the transfusion of a large number of lymphocytes.

[Emergency treatment of severe bleeding in idiopathic thrombocytopenic purpura].

In patients with severe idiopathic thrombocytopenic purpura(ITP), life-threatening hemorrhage such as intracranial or gastrointestinal hemorrhage can occur spontaneously. In this emergency situation. an attempt to increase platelet count should be done. In general, appropriate regimens include intravenous immunoglobulin and high-dose parenteral methylprednisolone either alone or in combination. These treatments should be followed by platelet transfusions, although platelets might be rapidly removed from the circulation. In this article, the strategies for emergency treatment of severe bleeding in ITP is briefly reviewed.

Novel DNA sequence isolated from blood donors with high transaminase levels.

AIM: In Japan, the etiology of 10-20% of cases of acute hepatitis remains unclarified. This study was conducted to verify the agent causing non-A-E hepatitis. METHODS: Serum samples from 500 blood donors with elevated alanine aminotransferase (ALT) levels were screened by polymerase chain reaction using primers constructed from conserved areas of RNA virus helicase. The sequence obtained was investigated for viral properties. RESULTS: Four blood samples were found to contain a novel DNA sequence of 9496 bp, which was designated KIs-V. KIs-V was sensitive to the restriction enzyme SalI and BstXI. Rolling-circle amplification produced an excessive amount of KIs-V DNA. In sucrose density gradient ultracentrifugation, KIs-V banded at a 1.158-g/cm(3) density. Detergent treatment increased the density of KIs-V. There was no KIs-V DNA amplification from human leukocyte DNA. Serial filtration suggested that KIs-V was included in a 30-50-nm size particle. In silico analysis revealed that KIs-V contained 13 potential genes, none of which showed homology to any viral proteins reported. One gene showed similarity to a DNA polymerase domain. Strong signals for transcription initiation and a CpG island were identified. The nucleotide composition of KIs-V showed a characteristic feature of circular DNA genomes that contain a replication origin and a terminus. In a preliminary study, KIs-V was frequently identified among hepatitis E virus antibody positive individuals with elevated ALT levels. CONCLUSION: A new sequence KIs-V was isolated from blood donors with elevated ALT levels. It was suggested that KIs-V is a double-stranded circular DNA genome derived from a novel category of enveloped viruses.