Lack of clinical utility of minimal residual disease detection in allogeneic stem cell recipients with childhood acute lymphoblastic leukemia: multi-institutional collaborative study in Japan

The clinical utility of minimal residual disease (MRD) measurements following allogeneic stem cell transplantation (SCT) in childhood ALL is controversial. We therefore performed a multi-institutional study of MRD in bone marrow samples taken before SCT and at 1, 3, 6 and 12 months after SCT. Case-specific clonal rearrangements of IgH and TCR genes and expression levels of Wilms' tumor 1 (WT1) mRNA were determined by PCR or RT-PCR methods. In total, 95 cases met all criteria for analysis of informative IgH/TCR markers and quantitative WT1 mRNA expression levels. During the 2-year (median 414 days) study period, 20 patients relapsed. Although the proportion of patients with a positive IgH/TCR result before SCT was significantly reduced at 1 month after treatment (P<0.001), attesting the efficacy of SCT, serial measurements of IgH/TCR rearrangements did not correlate with leukemic relapse. Clonal switch was demonstrated in 11 of the 14 patients with bone marrow relapse, indicating that the poor predictive power of the MRD assay most likely reflected the loss of PCR targets. WT1 expression was not related to either MRD detection by IgH/TCR assays or to clinical leukemic relapse. The clinical value of serial MRD monitoring would be limited in ALL patients undergoing SCT.

Acute renal failure due to adenovirus-associated obstructive uropathy and necrotizing tubulointerstitial nephritis in a bone marrow transplant recipient

Management of post-transplant complications caused by severe adenoviral infection remains a major therapeutic challenge. A 17-year-old male who had undergone bone marrow transplantation for the treatment of acute lymphoblastic leukemia developed complete anuria following hemorrhagic cystitis 34 days after the transplant procedure. The computed tomogram scan revealed bilateral hydronephrosis, indicating acute renal failure because of obstructive uropathy. The emergency procedure of percutaneous nephrostomy caused massive bleeding in the left kidney, which eventually required a nephrectomy. Adenovirus-positive severe necrotizing tubulointerstitial nephritis was the histopathological diagnosis. Post-transplant acute renal failure because of hydronephrosis, which could be complicated by adenovirus-induced renal parenchymal disease, is of great concern and may cause significant problems with interventional treatment.

Characteristic perforin gene mutations of haemophagocytic lymphohistiocytosis patients in Japan

Perforin gene (PRF1) mutations appear to occur in about 30% of patients with haemophagocytic lymphohistiocytosis (HLH). We tested perforin expression and gene mutations in 14 HLH patients and six patients with Epstein-Barr virus-associated HLH (EBV-HLH) in Japan. Five of the 14 HLH patients had perforin abnormalities. The presence of PRF1 genetic abnormality correlated well with the lack of perforin expression as determined by flow cytometry. Sequencing showed that four patients had a compound heterozygous mutation while the fifth patient had a homozygous mutation. Three of the mutations we detected were novel. In contrast, none of the six EBV-HLH patients showed perforin abnormalities. Our data, combined with the PRF1 mutations in three previously reported Japanese patients, suggest that the 1090-1091delCT and 207delC mutations of the perforin gene are frequently present in Japanese HLH patients (62.5% and 37.5% respectively). Examination of the geographical origins of the ancestors in the perforin-mutant HLH patients revealed that they mostly came from the Western part of Japan, suggesting that the present-day cases may largely derive from a common ancestor.

Hemophagocytic syndrome associated with severe adenoviral pneumonia: usefulness of real-time polymerase chain reaction for diagnosis

In infection-associated hemophagocytic syndrome (HPS) the causative pathogen is often undetected, except in cases of herpes virus infections. We describe a 12-year-old girl with life-threatening pneumonia with HPS caused by an adenovirus. She was admitted with complaints of persistent fever and systemic petechiae/purpura. The day after admission the patient developed sudden dyspnea with massive infiltration of the bilateral lower lung field. She exhibited coagulopathy, hepatic dysfunction, and remarkable elevations in serum levels of cytokine, ferritin, and urinary beta2-microglobulin. A diagnosis of HPS was made, and the patient was treated with dexamethasone and cyclosporin A on the second hospital day. Her fever went down quickly, and the abnormal laboratory and chest radiographic findings returned to normal over a period of 2 weeks. Antibody analysis was not successful in identifying the pathogen responsible. However, a polymerase chain reaction (PCR) assay of lung tissue biopsied on the fifth hospital day was positive for an adenovirus (subgroup B), and quantitative adenoviral DNA analysis by real-time PCR using primers covering serotypes 3, 7,11, and 35 (all subgroup B) confirmed this initial finding (93 copies/microg DNA in the biopsied lung and no detectable adenovirus DNA in the lung tissues of control subjects). This approach may provide important clues for improving outcomes and clarifying the exact etiology in cases of often fatal, infection-associated HPS.

Rearrangement of the MOZ gene in pediatric therapy-related myelodysplastic syndrome with a novel chromosomal translocation t(2;8)(p23;p11)

In this study, we examined a pediatric case of therapy-related myelodysplastic syndrome (tMDS). The symptoms developed 17 months after treatment for acute myeloblastic leukemia (AML, M2 subtype according to the French-American-British [FAB] classification) involving a chromosome abnormality at t(8;21)(q22;q22). Upon diagnosis of tMDS, spectral karyotyping analysis detected a new chromosomal translocation at t(2;8)(p23;p11.2). In addition, fluorescence in situ hybridization analysis suggested a rearrangement in the monocytic leukemia zinc finger (MOZ) gene, located in the 8p11 region of chromosome 8. However, no partner gene on 2p23 could be identified. To our knowledge, this is the first report of tMDS associated with a rearrangement of the MOZ gene. MOZ-linked fusion proteins such as MOZ-CBP (CREB binding protein), MOZ-TIF2 (transcriptional intermediary factor 2), and MOZ-p300 (adenoviral E1A-associated protein) are associated with AML chromosomal abnormalities at t(8;16)(p11;p13), inv(8)(p11q13), and t(8;22)(p11;q13), respectively, and are thought to account for leukemogenesis occurring through the aberrant regulation of histone acetylation. Through a similar mechanism, we believe that MOZ, fused to an unidentified partner gene at 2p23, may have caused an alteration in histone acetylation, resulting in the development of tMDS in this patient.

Infected urachal cyst ruptured during medical palliation

Since most cases of urachal cyst are asymptomatic, they are frequently detected after complication by infection. Ruptured urachal cysts are frequently detected after complication by severe infections such as sepsis. We report on a 31-year-old man who was diagnosed preoperatively as having an infected urachal cyst and the decision was made to follow the patient because primary excision was scheduled to be performed a few days later. Symptoms were transiently relieved, but the cyst ruptured during medical palliation. We treated this case with a two-stage surgical procedure.

A preparatory regimen of total body irradiation, busulphan and melphalan for allogeneic bone marrow transplantation in childhood high-risk leukemia and lymphoma

The therapeutic results of allogeneic bone marrow transplantation (BMT), following a conditioning regimen of total body irradiation and busulphan and melphalan administration, were evaluated in 20 pediatric patients with high-risk leukemia or lymphoma. Twelve patients received BMT from HLA-matched related (MR) donors while eight received transplants from mismatched related or unrelated (MisR/UR) donors. The post-BMT five-year survival rates were much better for patients in the MR donor group (p = 0.0008). The outcomes of patients in the MisR/UR donor group were significantly worse. This was not due to disease recurrence, but to a high incidence of fatal post-transplant infections (p = 0.004). Nine out of twelve patients who received transplants from MR donors have remained in complete remission for a median of 57 (range 27-78) months. These results suggest that this conditioning regimen has a significant anti-neoplastic benefit useful for the preparation of pediatric patients receiving transplants from MR donors; however, refinement is essential before it can be used in patients receiving transplants from MisR/UR donors.

A novel infant acute lymphoblastic leukemia cell line with MLL-AF5q31 fusion transcript

Infant acute lymphoblastic leukemia (ALL) is characterized by the presence of the proB phenotype (CD10(-)/CD19(+)), poor prognosis and frequent rearrangement of the mixed lineage leukemia (MLL) gene. The most frequent rearrangement is t(4;11)(q21;q23), the role of whose product, the MLL-AF4 fusion transcript, has been extensively studied in leukemogenesis. In a cell line of infant leukemia with MLL rearrangement denoted KP-L-RY, panhandle PCR amplification of cDNA revealed the presence of a fusion transcript, MLL-AF5q31, indicating that AF5q31 is also a partner gene of MLL. In this fusion transcript the MLL exon 6 is fused in frame to the 5' side of the putative transactivation domain of AF5q31. The AF5q31 protein is a member of the AF4/LAF4/FMR2-related family of proteins, which have been suggested to play a role in hematopoietic cell growth and differentiation. The MLL-AF5q31 fusion transcript, although probably rare, appears to be associated with the pathogenesis of infant ALL like MLL-AF4. Co-expression of HoxA9 and Meis1 genes in the KP-L-RY cell line indicated possible functional similarity between MLL-AF4 and MLL-AF5q31. Further understanding of the function of AF5q31 as well as the specific leukemogenic mechanism of MLL-AF5q31 awaits future studies.

Frequent co-expression of HoxA9 and Meis1 genes in infant acute lymphoblastic leukaemia with MLL rearrangement

We studied the expression of HoxA9 and Meis1 by reverse transcriptase-polymerase chain reaction analysis in leukaemic cells from cases of infant acute lymphoblastic leukaemia (ALL, n = 27) and childhood ALL (n = 29). These two genes were co-expressed significantly more frequently in infant ALL than in childhood ALL (19/27 vs0/29 cases, P < 0.001) and were highly associated with MLL gene rearrangement in infant ALL cases (P < 0.001). These findings indicate that the HoxA9 and Meis1 genes are closely associated with MLL gene rearrangement in the development of infant ALL, which represents a distinct entity of childhood ALL.

Slug, a highly conserved zinc finger transcriptional repressor, protects hematopoietic progenitor cells from radiation-induced apoptosis in vivo

We show here that a zinc finger transcriptional repressor, Slug, which is aberrantly upregulated by the E2A-HLF oncoprotein in pro-B cell acute leukemia, functions as an antiapoptotic factor in normal hematopoietic progenitor cells. Slug(-/-) mice were much more radiosensitive than wild-type mice, dying earlier and showing accentuated decreases in peripheral blood cell counts, as well as abundant microhemorrhages and widely disseminated bacterial microabscesses throughout the body. Slug expression was detected in diverse subsets of hematopoietic progenitors, but not in more differentiated B and T lymphoid cells, and there was a significant increase in apoptotic (TUNEL-positive) bone marrow progenitor cells in irradiated Slug(-/-) mice compared to wild-type controls. These results implicate Slug in a novel survival pathway that protects hematopoietic progenitors from apoptosis after DNA damage.

Successful transplantation of haploidentical CD34+ selected bone marrow cells for an infantile case of severe combined immunodeficiency with aspergillus pneumonia

A 5-month-old boy with X-linked severe combined immunodeficiency (SCID) and aspergillus pneumonia was successfully transplanted. Before and during transplantation, the patient received O2 administration, systemic amphotericin B, and itraconazole. The transplant was performed with a conditioning regimen of busulfan/cyclophosphamide and 2.9 x 10(6)/kg of CD34+ selected bone marrow cells from his HLA haploidentical mother. Acute grade II graft-versus-host disease (GvHD) was well controlled. Neutrophil counts reached >0.5 x 10(9)/L by day 15 and platelet counts reached > 50 x 10(9)/L by day 48. The T-cell subset (counts) in peripheral blood increased to 42.2% (0.31 x 10(9)/L) by day 46. The pneumonia improved by day 54. The patient has been doing well with limited chronic GvHD of the gut with a follow-up of longer than 40 months after BMT. Conquest of aspergillus pneumonia in SCID infants could be achieved by CD34+ bone marrow cell transplantation together with appropriate anti-fungal treatment.

Epstein-Barr virus-associated T-lymphoproliferative disease with hemophagocytic syndrome, followed by fatal intestinal B lymphoma in a young adult female with WHIM syndrome. Warts, hypogammaglobulinemia, infections, and myelokathexis

A rare association of Epstein-Barr virus-associated T- and B-lymphoproliferative disease (EBV(+) T- and EBV(+) B-LPD) in a patient with WHIM (warts, hypogammaglobulinemia, infections, and myelokathexis) syndrome is reported. A 26-year-old Japanese female, who had been treated for WHIM syndrome since early childhood, developed hemophagocytic syndrome associated with EBV(+) T-LPD at the lymph nodes and spleen. The disease rapidly resolved in response to prednisolone therapy. However, 6 weeks later, fatal EBV(+) B lymphoma unresponsive to chemotherapy occurred in the intestine and other organs. Caution must be exercised that the patient with WHIM syndrome may be at risk for EBV-LPD.

Aggregation and neurotoxicity of mutant amyloid beta (A beta) peptides with proline replacement: importance of turn formation at positions 22 and 23

Aggregation of the amyloid beta peptides (A beta 1-42 and A beta 1-40) plays a pivotal role in pathogenesis of Alzheimer's disease. Although it is widely accepted that the aggregates of A betas mainly consist of beta-sheet structure, the precise aggregation mechanism remains unclear. To identify amino acid residues that are important for the beta-sheet formation, a series of proline-substituted mutants of A beta 1-42 peptides at positions 19-26 was synthesized in a highly pure form and their aggregation ability and neurotoxicity on PC12 cells were investigated. All proline-substituted A beta 1-42 mutants except for 22P- and 23P-A beta 1-42 were hard to aggregate and showed weaker cytotoxicity than wild-type A beta 1-42, suggesting that the residues at positions 19-21 and 24-26 are important for the beta-sheet formation. In contrast, 22P-A beta 1-42 extensively aggregated with stronger cytotoxicity than wild-type A beta 1-42. Since proline has a propensity for beta-turn structure as a Pro-X corner, these data implicate that beta-turn formation at positions 22 and 23 plays a crucial role in the aggregation and neurotoxicity of A beta peptides.

Expression of the Ikaros gene family in childhood acute lymphoblastic leukaemia

The Ikaros (Ik) gene family, which includes Ik, Aiolos (Ai), and Helios (He), is a primary regulator of lymphocyte differentiation, and is involved in the development of acute lymphoblastic leukaemia (ALL). We analysed the expression of the Ik gene family isoforms in 97 ALL cases, consisting of 64 childhood and 33 infant ALL cases, using reverse transcription-polymerase chain reaction (RT-PCR). Expression of Ik was detected in all cases, 87 of which expressed either Ik1 or Ik2, or both, five of which expressed Ik1/Ik2 and Ik6, and another five of which expressed only Ik6. Therefore, the dominant negative isoform of Ik6 was expressed in 10 of the 38 cases of childhood precursor B ALL, but was absent in other types of childhood ALL (26.3%, chi2-test, P = 0.0001). In terms of Aiolos and Helios expression, 49 (65.3%) out of the 75 and 40 (50%) out of the 80 ALL cases tested showed non-spliced Ai1 and He1 respectively. Only one case of T lineage ALL expressed a small-sized isoform of Helios (designated as He6). It was also found that the expression of Ai1 and He1 was low in Ik6-positive patients (Fisher's exact test; Ai1 P = 0.005, Hel P = 0.035).

Synthesis, aggregation, neurotoxicity, and secondary structure of various A beta 1-42 mutants of familial Alzheimer's disease at positions 21-23

Cerebral amyloid angiopathy (CAA) due to amyloid beta (A beta) deposition is a key pathological feature of Alzheimer's disease (AD), especially in some form of familial Alzheimer's disease (FAD) including hereditary cerebral hemorrhage with amyloidosis-Dutch type. A beta mainly consists of 40- and 42-mer peptides (Abeta 1-40 and A beta 1-42), which accumulate in senile plaques of AD brains and show neurotoxicity for cultured nerve cells. We synthesized all variant forms of A beta 1-42 associated with reported FAD, such as A21G (Flemish), E22Q (Dutch), E22K (Italian), E22G (Arctic), and D23N (Iowa) along with three potential mutants by one point missense mutation (E22A, E22D, and E22V) in a highly pure form, and examined their ability to aggregate and their neurotoxicity in PC12 cells. The mutants at positions 22 and 23 showed potent aggregative ability and neurotoxicity whereas the potential mutants did not, indicating that A beta 1-42 mutants at positions 22 and 23 play a critical role in FAD of Dutch-, Italian-, Arctic-, and Iowa-types. However, Flemish-type FAD needs alternative explanation except the aggregation and neurotoxicity of the corresponding A beta 1-42 mutant.

Somatic cell mutation in pediatric patients undergoing allogeneic bone marrow transplantation

In order to examine whether bone marrow transplantation (BMT) has genotoxic effects in vivo, mutant frequencies (Mfs) at the hypoxanthine-guanine phosphoribosyl transferase (Hprt) locus were evaluated. Thirty-seven pediatric patients who had received allogeneic BMT for various hematologic or immunologic disorders were enrolled. Nine out of the 37 patients (24.3%) were found to have Hprt-Mfs exceeding the 99% confidence limits calculated from observation of healthy controls. Among factors including gender, primary disease of the patient, donor-recipient histocompatibility relationship, age of donor, and total body irradiation as conditioning regimen, none was associated with an increased Hprt-Mf. In three patients who had chimerism in their peripheral blood after BMT, Hprt mutant clones turned out to be of donor- or recipient-origin. Mfs at the T-cell receptor (TCR) locus were examined in 28 patients. Four patients (14.3%) were found to have increased TCR-Mfs. However, there were not any patients who showed elevation of both Hprt-and TCR-Mfs. These data, taken together, suggest that BMT may cause genotoxicity in vivo in some patients.

Percutaneous ethanol injection under CT fluoroscopy for hypervascular hepatocellular carcinoma following transcatheter arterial embolization

BACKGROUND/AIMS

The present study was conducted to accurately monitor the pattern of ethanol distribution during percutaneous ethanol injection by computed tomography fluoroscopy and to examine the relationship between the distribution pattern and therapeutic effect.

METHODOLOGY

Twenty-five hypervascular hepatocellular carcinomas were studied. Each was treated with transcatheter arterial embolization. However, as residual parts were detected, percutaneous ethanol injection under real-time computed tomography fluoroscopy was performed. For analysis, ethanol distribution and local recurrence rate were compared.

RESULTS

Ethanol distribution in a tumor was classifiable into 3 patterns. In pattern 1, ethanol solution was distributed spherically. In pattern 2, ethanol solution spread forming linear boundaries indicating interruption of distribution by septa. In pattern 3, ethanol spread circumferentially only along the periphery sparing the central part of a tumor. The 6-month recurrence rate of the tumors in which ethanol solution was distributed to the whole viable part was 25% (pattern 1), 100% (pattern 2) and 0% (pattern 3), respectively.

CONCLUSIONS

In the tumors showing distribution pattern 3 by computed tomography fluoroscopy, a combination therapy of transcatheter arterial embolization and percutaneous ethanol injection was more effective than in other patterns. Computed tomography fluoroscopy was useful for accurate monitoring and predicting the therapeutic effect of percutaneous ethanol injection.

Three-directional spectral dispersion for smoothing of a laser irradiance profile

In inertial confinement fusion research, uniform laser irradiation on a fusion target is a key issue. We propose a new method of beam smoothing in which we use three-directional spectral dispersion to reduce the coherent speckle that is unavoidable in the usual two-directional spectral-dispersion scheme. We have used this smoothing technique in a Nd:glass laser system and have demonstrated that the coherent speckle is reduced by a factor of 2.9 from that in two-directional spectral dispersion.

[Examination of patient factors and contrast medium factors that exert influence on contrast enhancement]

PURPOSE

To determine the relationship between patient factors and contrast medium factors, both of which influence contrast enhancement. Our goal was to achieve improved standardization and reproducibility of enhancement based on the findings of this study.

METHODS

Enhancement units(EU) and the contrast enhancement index(CE index) were calculated in the areas of the hepatic parenchyma and abdominal aorta in 370 subjects who underwent our hepatic dynamic study. We analyzed the obtained values in terms of differences in age, sex, body weight, iodine volume per body weight, and volume and concentration of contrast medium.

RESULTS

Changes in EU values were dependent on total iodine volume and body weight, showing a positive correlation with iodine volume per body weight. When assessed in terms of fixed total volume, the values were found to show a negative correlation with body weight. The obtained CE index values were closely distributed on a fixed iodine volume per weight, with slight variations that were related to sex, body weight, and age. Particularly, in the analysis of changes in enhancement levels according to age, a notable increase in contrast enhancement in inverse relationship with decline in glomerular filtration rate(GFR) with aging was observed.