Akio Kohno

Successful ribavirin therapy for severe adenovirus hemorrhagic cystitis after allogeneic marrow transplant from close HLA donors rather than distant donors.

Intravenous ribavirin was given to nine patients who had developed severe adenovirus-induced hemorrhagic cystitis (AD-HC) which was resistant to conventional therapy or where there was involvement of other organs after allogeneic BMT. Three patients recovered completely from AD-HC, two of whom had been resistant to vidarabine. All three had received sibling BMTs (2 HLA matched, 1 HLA mismatched). Five patients who received BMTs from related (2 HLA mismatched) or unrelated (1 HLA matched, 2 HLA mismatched) showed an improvement in symptoms but had recurrent AD-HC after discontinuation of ribavirin. Improvement in clinical symptoms and termination of virus excretion were well correlated. The last patient who received a mismatched unrelated BMT died during ribavirin therapy. Ribavirin was notably more effective among patients receiving BMTs from siblings in contrast to patients receiving BMTs from alternative donors (<0.05). One patient experienced severe pancytopenia during the second treatment with ribavirin after hc recurrence and recovered after ceasing ribavirin. Thus, ribavirin seems to be very effective for severe ad-hc for some recipients who receive transplants from a genetically close donor. Bone Marrow Transplantation (2000) 25, 545–548.

BMI-1 is Highly Expressed in M0-Subtype Acute Myeloid Leukemia

Recent studies have suggested that one of the polycomb group genes,BMI- 1, has an important role in the maintenance of normal and leukemic stem cells by repressing theINK4a/ARF locus. Here, we quantitatively examinedBMI- 1 expression level in samples from patients with acute myeloid leukemia (AML) and other hematologic malignancies. Moderate to highBMI- 1 expression was detected in AML patients, and theBMI- 1 expression levels in AML samples were significantly higher than in normal bone marrow controls(P =.0011). Specimens of French-American-British classification subtype M0 showed higher relative expression of the BMI-1 transcript (median, 390.2 x 10-3) than the other subtypes (median, 139.0 x 10-3)(P <.0001). Leukemia other than AML showed low to moderate expression. INK4a-ARF transcript expression tended to be inverse proportion to that of BMI-1. In an M0 patient with a high BMI-1 transcript level, the INK4a-ARF transcript level fell promptly and maintained a low value after the patient achieved complete remission. These results indicated that a subgroup of M0 patients has a high expression level of polycomb group geneBMI- 1, which may contribute to leukemogenesis.

Short-term methotrexate could reduce early immune reactions and improve outcomes in umbilical cord blood transplantation for adults

Post transplant immune disorders are problematic in cord blood transplantation (CBT) for adult patients, and optimal prophylaxis has not been established. We investigated whether intensive graft-versus-host disease (GVHD) prophylaxis using short-term methotrexate (MTX) has a prognostic impact on CBT. Post-CBT immune reactions were classified according to time course as pre-engraftment immune reaction (PIR), engraftment syndrome (ES) or acute GVHD. Between March 2001 and November 2005, a total of 77 patients underwent CBT at eight transplantation centers. Median age was 48 years (range, 18–69 years). Preparative regimens comprised myeloablative (n=31) or reduced-intensity (n=46). Acute GVHD prophylaxis included cyclosporine alone (n=23), tacrolimus alone (n=12), cyclosporine plus MTX (n=17), tacrolimus plus short-term MTX (n=23) or cyclosporine plus methylprednisolone (n=2). Cumulative incidences of PIR, ES and grade II–IV GVHD were 36, 12 and 23%, respectively. Short-term MTX exerted significant favorable effects on post-CBT immune reactions (hazard ratio, 0.55; 95% confidence interval (95% CI), 0.31–0.98; P=0.04) in multivariate analysis. Overall survival rates for patients with and without short-term MTX at day 180 were 59% (95% CI, 42–73%) and 16% (95% CI, 6.6–30%) (P=0.0001), respectively. Short-term MTX could offer one optimal regimen to reduce immune reactions and improve outcomes in CBT.

Solid tumors after hematopoietic stem cell transplantation in Japan : incidence, risk factors and prognosis

Summary:To evaluate the incidence, risk factors and prognosis for solid tumors after hematopoietic stem cell transplantation (HSCT) in Japan, 809 patients who had received HSCT between 1981 and 2000 were retrospectively analyzed. In all, 19 newly diagnosed secondary cancers were observed. The risk for cancer development was 2.8 times as high as that for expected cases. The cumulative incidence ratios at 5 and 10 years were 1.9 and 4.2%, respectively. The risk was significantly elevated for buccal cavity cancer (standard incidental ratio (SIR), 44.42: 95% confidence interval (CI) 17.86–91.51), esophageal cancer (SIR, 22.36: 95% CI 6.09–57.25), and cervical cancer (SIR, 8.58: 95% CI 1.04–31.01). Of 15 patients who developed solid cancers following allografting, 12 had chronic graft-versus-host disease (GVHD), and all 10 patients with squamous cell carcinoma of the buccal cavity or esophagus had chronic GVHD. On multivariate analysis, extensive chronic GVHD and age over 45 years at the time of transplantation were associated with a higher risk for solid cancers. In all, 17 patients received therapy for secondary cancers, nine of whom are still alive and the 5-year probability of survival from the diagnosis is 42.8%. Our data suggest that early detection of secondary cancers is very important in prolonging overall survival.

Semliki Forest virus-based DNA expression vector: transient protein production followed by cell death.

We have constructed a novel DNA expression vector based on Semliki Forest virus (SFV). SFV produces nonstructural proteins (nsPs) which replicate genomic RNA and amplify the mRNA encoding the structural proteins of SFV. A recombinant cDNA genome of SFV, in which the SFV structural genes were replaced by a polylinker cassette to allow for insertion of heterologous DNA, was placed under the control of a cytomegalovirus immediate–early enhancer/promoter with a polyadenylation signal. Transfection of mammalian cells with this SFV-based plasmid vector, pSFV3-CMV-lacZ-pA, resulted in transient high-level expression of a β-galactosidase reporter gene. The expression level of β-galactosidase from pSFV3-CMV-lacZ-pA was more than 20-fold higher than that obtained from the plasmid with deleted nsPs genes, pSFV3A5976-lacZ, demonstrating that the nsPs genes were essential for the high level of expression. Substantial β-galactosidase activity was detected in the medium of pSFV3-CMV-lacZ-pA-transfected cells, suggesting that the overproduction of β-galactosidase caused cell death and release of the protein into the medium. We have demonstrated a high-level expression of the exogenous β-galactosidase gene from pSFV3-CMV-lacZ-pA constructed using an SFV replication system.

Cytomegalovirus antigenemia and outcome of patients treated with pre-emptive ganciclovir: Retrospective analysis of 241 consecutive patients undergoing allogeneic hematopoietic stem cell transplantation

Summary:CMV disease remains a major infectious complication after allogeneic hematopoietic stem cell transplantation (HSCT). To investigate the relationship between CMV antigenemia, treatment with ganciclovir (GCV), and outcome, we retrospectively analyzed 241 consecutive patients at risk for CMV infection who underwent allogeneic HSCT. Antigenemia-guided pre-emptive strategy with GCV was used for all patients. CMV antigenemia developed in 169 patients (70.1%), and CMV disease in 18 patients (7.5%). Multivariate analysis showed that acute GVHD (grades II–IV) was the only risk factor for developing antigenemia, and acute GVHD and advanced age for CMV disease. GCV use, as well as acute GVHD and advanced age, significantly increased the risk for bacterial and fungal infection after engraftment. Those who developed CMV antigenemia had a poorer outcome than those who did not (log-rank, P=0.0269), although the development of CMV disease worsened the outcome with only borderline significance (log-rank, P=0.0526). In conclusion, detection of antigenemia proved to be a poor prognostic factor for HSCT patients, which may be attributed to a combination of factors, including CMV disease itself, the effect of treatment, and a host status that allows for reactivation of CMV. Optimal pre-emptive strategy needs to be determined.

Trough plasma concentration of imatinib reflects BCR-ABL kinase inhibitory activity and clinical response in chronic-phase chronic myeloid leukemia : A report from the BINGO study

Pharmacokinetic (PK) factors have been suggested to be involved in the unfavorable clinical responses of chronic myeloid leukemia (CML) patients treated with imatinib. The purpose of this study was to clarify prognostic implications of PK factors in CML patients treated with imatinib. The plasma trough (Cmin) level of imatinib and serum α1‐acid glycoprotein (AGP) level were measured on two different days in 65 CML patients treated with imatinib for more than 12 months. We further examined whether the Cmin level of imatinib actually reflects inhibitory activity against BCR–ABL kinase using the plasma inhibitory activity (PIA) assay. Since the differences of five patients were statistically rejected by the Smirnov–Grubbs’ test, we excluded them for further analysis. The Cmin level was strongly associated with the achievement of MMR at the 12th month, and ROC analysis demonstrated Cmin levels and their discrimination potential for major molecular response (MMR) with the best sensitivity (63.2%) and specificity (68.2%) at a Cmin threshold of 974 ng/mL. The α1‐Acid glycoprotein (AGP) level was within the normal range in 57 of 60 patients, indicating little impact of AGP on our study. There was a weak correlation between PIA against phospho (P)‐BCR–ABL and the Cmin level of imatinib (r2 = 0.2501, P = 0.0007), and patient plasma containing >974 ng/mL imatinib sufficiently inhibited P‐BCR‐ABL. These results collectively indicated that maintaining ∼1000 ng/mL of Cmin was clinically and biologically important for the optimal response in CML patients treated with imatinib. A prospective intervention study is required to establish PK‐based management in CML patients treated with imatinib. (Cancer Sci 2010)

Clinicopathological manifestations and treatment of intestinal transplant-associated microangiopathy

Intestinal transplant-associated microangiopathy (i-TAM) is an important complication after allogeneic hematopoietic SCT. From 1997 to 2006, 87 of 886 patients with diarrhea after transplantation received colonoscopic biopsy. i-TAM, GVHD and CMV colitis were diagnosed histopathologically. The median duration from transplantation to the onset of diarrhea was 32 days (range: 9–130 days) and that from the onset of diarrhea to biopsy was 12 days (range: 0–74 days). The median maximal amount of diarrhea was 2 l/day (range: 130–5600 ml/day). Histopathological diagnosis included i-TAM (n=80), GVHD (n=26), CMV colitis (n=17) and nonspecific findings (n=2) with overlapping. Among 80 patients with i-TAM, abdominal pain was a major symptom, and only 11 patients fulfilled the proposed criteria for systemic TAM. Non-relapse mortality (NRM) among patients without resolution of diarrhea was 72% and i-TAM comprised 57% of NRM. NRM was 25% among patients without intensified immunosuppression, but was 52, 79 and 100% among those with intensified immunosuppression before diarrhea, after diarrhea, and before and after diarrhea, respectively. In conclusion, i-TAM is a major complication presenting massive refractory diarrhea and abdominal pain, which causes NRM. Avoiding intensified immunosuppression that damages vascular endothelium until the resolution of i-TAM may improve transplant outcome.

Usefulness of Bone Marrow Aspiration for Definite Diagnosis of Asian Variant of Intravascular Lymphoma: Four Autopsied Cases

The Asian variant of intravascular lymphoma (AIVL) is characterized by hemophagocytic syndrome, pancytopenia and hepatosplenomegaly but usually lacks any neurological abnormality and skin lesions, which are typical features of classical intravascular lymphoma (IVL). An ante-mortem diagnosis of AIVL is difficult due to the absence of visible lymphoma lesions and unspecific clinical manifestations. A definite diagnosis relies on the presence of neoplastic B cells in the lumina of small vessels. Paraffin block samples of aspirated bone marrow clots were obtained from 4 patients with clinically suspected IVL and subjected to immunohistopathological analysis. All samples exhibited CD 20+ or CD 79a+ lymphoma cells proliferating intravascularly as well as erythrocytic hemophagocytosis. The distribution of neoplastic cells in the structure of the bone marrow allowed IVL to be distinguished from bone marrow invasions due to other types of lymphoma. We demonstrated the successful establishment of a definite ante-mortem diagnosis of AIVL in 3 of 4 patients by the rapid and simple method of using aspirated bone marrow samples.

Multiplex real-time RT-PCR for prospective evaluation of WT1 and fusion gene transcripts in newly diagnosed de novo acute myeloid leukemia

Prognostic assessment is crucial for the management of AML. Although the use of karyotype analysis for risk-stratification is widely accepted, prognosis of AML remains ambiguous, particularly for patients categorized into the intermediate cytogenetic risk group and additional markers are required for an accurate prediction of outcome. For this study, we used multiplex real-time RT-PCR, which can simultaneously quantify WT1 and 10 distinct fusion gene transcripts, to prospectively evaluate the pre-treatment bone marrow findings of 53 de novo AML patients. Five patients with normal karyotype or insufficient metaphases detected by conventional karyotype analysis proved to have AML1-MTG8, CBFbeta-MYH11 or PML-RARalpha fusion transcripts. WT1 overexpression was observed in 92% of the patients, and the levels were significantly higher in the cytogenetic favorable risk group, especially patients with PML-RARalpha. WT1 levels also correlated with the percentage of blasts in bone marrow, especially in cases of core-binding factor leukemia. There was no association between initial WT1 levels and outcome in terms of event-free survival or overall survival. These results suggest that multiplex real-time RT-PCR is rapid and useful for the precise cytogenetic stratification of AML, and that WT1 levels at presentation correlate with several biologic features of leukemia, but have no prognostic significance.