Kazuhiro Kohno

Human Herpesvirus 6 DNA in Plasma after Allogeneic Stem Cell Transplantation: Incidence and Clinical Significance

BACKGROUND Human herpesvirus 6 (HHV-6) is increasingly recognized as an opportunistic and potentially life-threatening pathogen in recipients of allogeneic stem cell transplants (SCTs). METHODS To clarify the incidence and clinical relevance of active HHV-6 infection, serial titers of plasma HHV-6 DNA were determined for 50 allogeneic SCT recipients, using real-time polymerase chain reaction. RESULTS HHV-6 DNA was detected in plasma from 24 patients (48%). HHV-6 DNA was most frequently apparent approximately 14-27 days after transplantation. An increased risk of a positive result for HHV-6 DNA was associated with transplantation from an allelic-mismatch donor (P = .02) and administration of steroids (P = .04). Steroid use was associated with high HHV-6 DNA loads (P = .02). High HHV-6 DNA loads were correlated with delayed platelet engraftment (P = .04). Among patients who had positive results for HHV-6 DNA, the HHV-6 DNA load was higher in plasma from those who developed limbic encephalitis (n = 4) (P < .0001). CONCLUSIONS Active HHV-6 infection is not rare in SCT recipients. SCT from allelic-mismatch donors is associated with increased risk of active HHV-6 infection. Steroid therapy is associated with not only increased incidence of infection but also accelerated viral replication. Development of limbic encephalitis is associated with high HHV-6 DNA load.

Sequential analyses of the mutations in the core upstream and precore regions of hepatitis B virus genome in anti-HBe positive-carriers developing acute exacerbation.

The nucleotide sequences of the core upstream and precore regions (371 nucleotide length, nt. 1604‐1974) of hepatitis B virus (HBV) were analysed sequentially in three subjects who were positive serorogically for anti‐HBe and had acute clinical exacerbation after immunosuppressive treatment. These patients were asymptomatic HBV carriers before therapy. The results revealed that the mutant with an 8‐bp deletion (nt. 1768–1775) located in the basic core promoter region was dominant in the asymptomatic HBV carrier phase in two of three subjects. After exacerbation, however, such mutant clones possessing 8‐bp deletion disappeared or decreased in number and were replaced by the clones possessing a precore stop codon mutation G to A (nt. 1896) or by the clones possessing additional contiguous point mutations A to T (nt. 1762) and G to A (nt. 1764) and a new point mutation C to T (nt. 1653). Possible relationships between acute exacerbation of liver function accompanied by mutation and the transition of the dominant clones were discussed. J. Med. Virol. 53:266–272, 1997.

Foscarnet against human herpesvirus (HHV)-6 reactivation after allo-SCT: breakthrough HHV-6 encephalitis following antiviral prophylaxis

High incidences of human herpesvirus (HHV)-6 encephalitis have recently been reported from several Japanese SCT centers. To evaluate the effect of low-dose foscarnet (PFA) in preventing HHV-6 infection among recipients of unrelated BM or cord blood (CB), we examined consecutive cohorts without prophylaxis against HHV-6 (Cohort 1, n=51) and with PFA prophylaxis (Cohort 2, PFA 50 mg/kg/day for 10 days after engraftment, n=67). Plasma real-time PCR assay was performed weekly. High-level reactivation defined as HHV-6 DNA⩾104 copies/mL by day 70 was the primary endpoint. No significant reduction of high-level reactivation was seen in Cohort 2 (19.4%) compared with Cohort 1 (33.8%, P=0.095). A trend was identified toward fewer high-level HHV-6 reactivations in Cohort 2 among recipients of unrelated BM (P=0.067), but no difference in incidence was observed among CB recipients (P=0.75). Breakthrough HHV-6 encephalitis occurred following PFA prophylaxis in three patients, and incidence of HHV-6 encephalitis did not differ between Cohort 1 (9.9%) and Cohort 2 (4.5%, P=0.24). In conclusion, 50 mg/kg/day of PFA does not effectively suppress HHV-6 reactivation and cannot prevent all cases of HHV-6 encephalitis. To effectively prevent HHV-6 encephalitis, alternative approaches based on the pathogenesis of HHV-6 encephalitis will probably be required.

Eosinophilia associated with adult T-cell leukemia: role of interleukin 5 and granulocyte-macrophage colony-stimulating factor.

To clarify the mechanism of eosinophilia in adult T‐cell leukemia (ATL), we studied three ATL patients having marked eosinophilia. Eosinophil‐predominant colony‐stimulating activity was detected in the serum of one patient and in the conditioned media (CM) from cultured ATL cells from two patients. Soluble interleukin 5 (IL‐5), but no interleukin 3 (IL‐3) and granulocyte‐macrophage colony‐stimulating factor (GM‐CSF), was detected in sera from all patients. On the other hand, GM‐CSF was produced in vitro by ATL cells from all cases, whereas detectable IL‐3 and IL‐5 was produced by cells from only one, suggesting that in the other two cases, the serum IL‐5 was produced by the normal reacting lymphocytes. The fact that no patient showed marked neutrophilia supports the possibility that IL‐5 may have a leading role in the development of eosinophilia, with GM‐CSF produced by ATL cells playing a complementary role. Am. J. Hematol. 59:242–245, 1998.

High incidence of cytomegalovirus, human herpesvirus-6, and Epstein–Barr virus reactivation in patients receiving cytotoxic chemotherapy for Adult T cell leukemia

The etiology of cytomegalovirus (CMV), human herpesvirus‐6 (HHV‐6), and Epstein–Barr virus (EBV) reactivation and the potential for complications following cytotoxic chemotherapy in the absence of allogeneic transplantation are not clearly understood. Patients with adult T cell leukemia (ATL) are susceptible to opportunistic infections. In this study, the incidence, kinetics and clinical significance of reactivation of CMV, HHV‐6, and EBV in ATL patients were investigated. Viral DNA in a total of 468 plasma samples from 34 patients was quantified using real‐time PCR. The probability of CMV, HHV‐6, and EBV reactivation by 100 days after the start of chemotherapy was 50.6%, 52.3%, and 21.6%, respectively. Although most CMV reactivations were self‐limited, plasma CMV DNA tended to persist or increase if the CMV DNA levels in plasma reached ≥104 copies/ml. CMV reactivation was negatively associated with survival, but the P‐value for this association was near the borderline of statistical significance (P = 0.052). One patient developed fatal interstitial pneumonia concomitant with peak CMV DNA accumulation (1.6 × 106 copies/ml plasma). Most HHV‐6 and EBV reactivations were self‐limited, and no disease resulting from HHV‐6 or EBV was confirmed. HHV‐6 and EBV reactivation were not associated with reduced survival (P = 0.35 and 0.11, respectively). These findings demonstrated that subclinical reactivation of CMV, HHV‐6, and EBV were common in ATL patients receiving chemotherapy. There were differences in the viral reactivation patterns among the three viruses. A CMV load ≥104 copies/ml plasma was indicative of subsequent exacerbation of CMV reactivation and developing serious clinical course. J. Med. Virol. 83:702–709, 2011.

Reduced transcription and progeny virus production of hepatitis B virus containing an 8-bp deletion in basic core promoter

We have demonstrated previously the presence of an 8‐bp deletion mutant, spanning from nt. 1768 to nt. 1775 in the basic core promoter region of hepatitis B virus (HBV) in patients with anti‐HBe positive asymptomatic phase before developing acute exacerbation after immunosuppressive treatment. The transcription and progeny virus production activities of the mutant were examined by transfection of the recombinant plasmid [pUC Del(2)] containing the head‐to‐tail dimer DNA of the mutant into HepG2 cells. The amounts of hepatitis B surface antigen (HBsAg) and HBe antigens secreted into the culture medium were markedly reduced. Southern blotting of DNAs extracted from the culture medium also showed reduced mutant activity to produce progeny virus. Northern blotting and RNase protection assay of RNAs extracted from transfected cells demonstrated that the transcription of both precore mRNA and pregenome RNA was reduced significantly compared to that of wild‐type HBV. The promoter activity examined by transfection of the CAT plasmid containing deletion mutant DNA was much lower than that of wild type. Co‐transfection experiments, however, of the CAT plasmid containing wild‐type DNA with pUC Del(2) reduced CAT activity induced by wild‐type, suggesting that truncated X protein produced by the mutant does not possess a sufficient transactivating activity. Gel shift assay using HepG2 nuclear extract and a probe containing four TA‐rich regions in CP and various competitors suggested that the lack of the third TA‐rich region was responsible for the transcription reduction of precore mRNA and pregenome RNA. The possible mechanisms are discussed. J. Med. Virol. 61:15–22, 2000.

Mutations in the Core Promoter/Enhancer II Regions of Naturally Occurring Hepatitis B Virus Variants and Analysis of the Effects on Transcription Activities

The regulatory regions for transcription and replication of several hepatitis B virus (HBV) genomes from 19 patients having various forms of HBV infection were sequenced. Predominant mutations were found to occur naturally in nucleotide positions 1762 (A to T) and 1764 (G to A) in chronic hepatitis patients and in asymptomatic carriers after seroconversion, but were not observed in HBeAg-positive healthy carriers. Since these positions were located in the basic core promoter and the overlapping enhancer II regions situated within the core upstream region, transcriptional activity was examined by chloramphenicol acetyltransferase assay to determine if there was a possible difference between the mutant and wild-type HBV. However, no significant difference was detected upon comparison of the promoter and enhancer activities between mutant and wild-type HBV.

Development of hyperammonemic encephalopathy in patients with multiple myeloma may be associated with the appearance of peripheral blood myeloma cells

Hyperammonemia is one of the causes of metabolic encephalopathy with a wide spectrum of neuropsychiatric abnormalities. Recently, few patients with multiple myeloma (MM) have been reported to develop a loss of consciousness due to hyperammonemia [1–13]. However, little is known about the characteristics of this entity, its etiology or its prognosis. The present report describes three cases of MM with hyperammonemic encephalopathy and analyses the clinical features of this condition by including patients described in previously published reports.

A retrospective analysis to estimate target trough concentration of vancomycin for febrile neutropenia in patients with hematological malignancy.

BACKGROUND The target trough concentration of vancomycin in patients with febrile neutropenia has not been reported. The aim of this study was to estimate the target trough concentration for febrile neutropenia in patients with hematological malignancy. METHODS In this retrospective, single-center, observational cohort study, 63 hospitalized patients with hematological malignancy who were treated with vancomycin for febrile neutropenia due to bacteriologically documented or presumptive Gram-positive infections were analyzed. RESULTS A significant difference in the first trough concentration of vancomycin was observed between the response and non-response groups, and between the nephrotoxicity and non-nephrotoxicity groups. Multiple logistic regression analyses identified the first trough concentration as the only independent variable associated with clinical efficacy and nephrotoxicity of vancomycin. The areas under the ROC curves were 0.72 and 0.83 for clinical efficacy and nephrotoxicity, respectively. The cut-off values of the first trough concentration were 11.1 μg/ml for clinical efficacy (sensitivity 60%, specificity 87%) and 11.9 μg/ml for nephrotoxicity (sensitivity 77%, specificity 82%). CONCLUSIONS These results suggest a relationship of trough vancomycin concentration with clinical efficacy and incidence of nephrotoxicity. We propose a target trough vancomycin concentration of around 11.5 μg/ml for febrile neutropenia in patients with hematological malignancy.

Response to Cyclosporine Therapy in Patients with Myelodysplastic Syndrome : A Clinical Study of 12 Cases and Literature Review

Cyclosporine (CyA) was administered to 12 patients with myelodysplastic syndrome (MDS), and a response (major erythroid response, according to International Working Group criteria) was observed in 7 patients (58.3%). The median duration of response was 18 months (range, 3–22 months). Two patients are still responding and continuing to take CyA. Three patients stopped because of malignancy complications. To identify variables associated with responsiveness to CyA therapy, we analyzed the treatments of 72 MDS patients, comprising the 12 new patients and 60 patients previously described in the literature. Responses were observed in 44 of the 72 patients (61.1%). Univariate analyses revealed that higher daily dose of CyA (P for trend test, .007) and shorter disease duration (median, 5 months versus 17.5 months, P = .04) were factors significantly associated with response. No significant associations were observed between response and bone marrow features such as erythroid hypoplasia or hypoplastic marrow. Multivariate analysis also demonstrated that high CyA dose (>5 mg/kg per day) was significantly associated with response (P = .02). The present study showed that CyA therapy is useful for MDS patients with any marrow cellularity. Shorter disease duration is a pretreatment variable correlated with response, and a higher CyA dose results in a higher response rate. Int J Hematol. 2004;80:35-42. doi: 10.1532/IJH97.04051