Mycobacterial infections in adult patients with hematological malignancy.

We retrospectively analyzed the clinical and microbiological characteristics of adult patients with hematological malignancy and nontuberculous mycobacteria (NTM) infections from 2001 to 2010. During the study period, 50 patients with hematological malignancy and tuberculosis (TB) were also evaluated. Among 2,846 patients with hematological malignancy, 34 (1.2%) patients had NTM infections. Mycobacterium avium-intracellulare complex (13 patients, 38%) was the most commonly isolated species, followed by M. abscessus (21%), M. fortuitum (18%), and M. kansasii (18%). Twenty-six patients had pulmonary NTM infection and eight patients had disseminated disease. Neutropenia was more frequently encountered among patients with disseminated NTM disease (p = 0.007) at diagnosis than among patients with pulmonary disease only. Twenty-five (74%) patients received adequate initial antibiotic treatment. Five of the 34 patients died within 30 days after diagnosis. Cox regression multivariate analysis showed that chronic kidney disease (p = 0.017) and neutropenia at diagnosis (p = 0.032) were independent prognostic factors of NTM infection in patients with hematological malignancy. Patients with NTM infection had higher absolute neutrophil counts at diagnosis (p = 0.003) and a higher 30-day mortality rate (15% vs. 2%, p = 0.025) than TB patients. Hematological patients with chronic kidney disease and febrile neutropenia who developed NTM infection had significant worse prognosis than patients with TB infection.

Distinct association between aberrant methylation of Wnt inhibitors and genetic alterations in acute myeloid leukaemia.

BACKGROUND: Aberrant activation of Wnt signalling through hypermethylation of Wnt inhibitor genes is involved in several human malignancies, including acute myeloid leukaemia (AML). It remains unclear whether hypermethylation of Wnt inhibitors is associated with molecular gene mutations in the development of AML. METHODS: We investigated the association of the promoter hypermethylation of six Wnt inhibitors (Wif-1, SFRP1, SFRR2, SFRP4, SFRP5, and DKK1) with gene aberrations in the leukaemogenesis of 269 AML patients. RESULTS: In total, 166 patients (61.7%) had hypermethylation of at least one Wnt inhibitor. The majority (68.5%) of patients with Wnt inhibitor hypermethylation had concurrent Class II gene mutations that affect transcription factors or cofactors. There was a close association of Wif-1 hypermethylation with t(15;17) (P=0.0005) and CEBPA mutation (P<0.0001), DKK1 hypermethylation with t(8;21) (P<0.0001) and ASXL1 mutation (P=0.0078), SFRP-1 hypermethylation with t(8;21) (P<0.0001), SFRP-2 hypermethylation with AML1/RUNX1 mutation (P=0.0012), and SFRP-5 hypermethylation with MLL/PTD (P=0.0505). On the other side, hypermethylation of Wnt inhibitors was always negatively associated with NPM1 mutation and FLT3/ITD. CONCLUSION: There was distinct association between hypermethylation of individual Wnt inhibitors and specific gene aberrations, especially Class II mutations. The Wnt inhibitor hypermethylation might interact with genetic alterations in the leukaemogenesis.

High bone marrow angiopoietin-1 expression is an independent poor prognostic factor for survival in patients with myelodysplastic syndromes.

BACKGROUND: Angiogenic factors have an essential role in normal and pathologic angiogenesis. However, the clinical implication of angiogenic factor expression in myelodysplastic syndromes (MDS) remains unclear. METHODS: In this study, we sought to investigate the prognostic impact of the expression of genes encoding angiopoietin-1 (Ang-1), Ang-2, the receptor Tie2, vascular endothelial growth factor-A (VEGF-A) and VEGF-C in the bone marrow (BM) in 208 patients with newly diagnosed primary MDS. RESULTS: BM Ang-1 expression was significantly higher in MDS patients, especially those with higher-risk subtypes, than in normal controls. With a median follow-up time of 32.9 months, the disease transformed to acute leukaemia more frequently in the patients bearing higher Ang-1 expression than in those with lower expression (31.5% vs 18.6%, P=0.023). The MDS patients with higher Ang-1 expression had shorter overall survival than those with lower expression (median 20.8±4.5 months vs 63.3±17.8 months, P<0.001). Multivariate analyses showed that higher Ang-1 expression was an independent unfavourable prognostic factor for overall survival. There was no impact of the expression of other angiogenic factors on survival. CONCLUSION: BM Ang-1 expression may serve as a new biomarker to predict clinical outcome in MDS patients.

Sensitive measurement of quantity dynamics of FLT3 internal tandem duplication at early time points provides prognostic information.

BACKGROUND: The level of minimal residual disease (MRD) in acute myeloid leukemia (AML) at early time points (TPs) may be an important prognostic factor. Although internal tandem duplication of FLT3 (FLT3-ITD) as an MRD marker has been questioned for its instability based on semi-quantitative methods, we hypothesized that FLT3-ITD dynamics measured by sensitive quantitative real-time PCR at early TPs before appearance of instability may provide prognostic information. PATIENTS AND METHODS: We measured mutant quantity in 493 serial samples from 55 patients with a median follow-up time of 64.8 months. The FLT3-ITD quantities after induction (TP1) and after the first post-induction chemotherapy (TP2) were analyzed. RESULTS: We found that lower FLT3-ITD levels at TP2 predicted longer overall survival (OS) and disease-free survival (DFS) regardless of cytogenetic risk. Multivariate analysis showed that ≥3 log reduction of FLT3-ITD at TP2 independently predicted better DFS and a trend toward better OS. FLT3-ITD disappeared at relapse in 16.7% of patients and none in those harboring mutant NPM1 compared with 29.4% in those with wild-type NPM1 (P = 0.032). CONCLUSIONS: Though the mutation may disappear at relapse in a few patients, FLT3-ITD levels at early TPs after chemotherapy provide prognostic information. FLT3-ITD is significantly more stable in those with mutant NPM1.

The impact of oral herpes simplex virus infection and candidiasis on chemotherapy-induced oral mucositis among patients with hematological malignancies.

The aim of this study was to evaluate the influences of oral candidiasis and herpes simplex virus 1 (HSV-1) infections in chemotherapy-induced oral mucositis (OM). The medical records of 424 consecutive patients with hematological malignancies who had received chemotherapy at a medical center in Taiwan from January 2006 to November 2007 were retrospectively reviewed. The results of swab cultures of fungus and HSV-1 for OM were correlated with associated clinical features. Younger age, myeloid malignancies, and disease status other than complete remission before chemotherapy were significantly correlated with the development of OM. Risks of fever (p < 0.001) and bacteremia were higher in patients with OM. Among 467 episodes of OM with both swab cultures available, 221 were non-infection (47.3%) and 246 were related to either fungal infections, HSV-1 infections, or both (52.7%); of the 246 episodes, 102 were associated with fungal infections alone (21.8%), 98 with HSV-1 infections alone (21%), and 46 with both infections (9.9%). Patients who had received antifungal agents prior to OM occurrence tended to have HSV-1 infection (p < 0.001). Our results suggest that Candida albicans and HSV-1 play an important role in chemotherapy-induced OM in patients with hematological malignancies.

Epidemiology of bloodstream infections in patients with haematological malignancies with and without neutropenia.

All bacterial isolates from 7058 patients admitted to haemato-oncology wards at National Taiwan University Hospital between 2002 and 2006 were characterized. In total 1307 non-duplicate bloodstream isolates were made from all patients with haematological malignancy; 853 (65%) of these were from neutropenic patients. Gram-negative bacteria predominated (60%) in neutropenic isolates with Escherichia coli (12%), Klebsiella pneumoniae (10%), Acinetobacter calcoaceticus-baumannii complex (6%), and Stenotrophomonas maltophilia (6%) the most frequent. Coagulase-negative staphylococci (19%) and Staphylococcus aureus (4%) were the most common Gram-positive pathogens. Resistance to ciprofloxacin was found in 50% of E. coli and 20% of K. pneumoniae isolates from neutropenic patients. Extensively drug-resistant A. calcoaceticus-baumannii complex and vancomycin-resistant enterococci were also found during the study period. Emerging antimicrobial resistant pathogens are an increasing threat to neutropenic cancer patients.

Prediction of fatal intracranial hemorrhage in patients with acute myeloid leukemia.

BACKGROUND: Intracranial hemorrhage (ICH) is the second leading cause of mortality in patients with acute myeloid leukemia (AML). However, the prognostic factors for ICH in AML patients are still under investigation. PATIENTS AND METHODS: A total of 841 AML patients admitted to the Department of Internal Medicine from January 1995 to December 2007 were enrolled in this study. RESULTS: There were 51 patients with ICH, median age of 51 (range 17-86), including 12 patients diagnosed as acute promyelocytic leukemia. Forty-three patients were refractory/relapsed status. ICH was localized in the supratentorium (44 cases), basal ganglion (9), cerebellum (5), and brainstem (4). Twenty-one patients had multiple sites. Thirty-eight patients had intraparenchymal hemorrhage, 16 subarachnoid hemorrhage (SAH), 10 subdural hemorrhage, and one epidural hemorrhage (EDH). Hemorrhage ruptured into the ventricles in 13 patients. Thirty-four patients (67%) died of ICH within 30 days of diagnosis. Multivariate analysis revealed four independent prognostic factors, prolonged prothrombin time international normalized ratio >1.5 (P < 0.001), brainstem hemorrhage (P = 0.001), SAH (P = 0.017), and EDH (P = 0.014). Other clinico-laboratory data had no impact on 30-day survival. CONCLUSIONS: ICH has high morbidity and mortality in AML. Early detection and aggressive correction coagulopathy may prevent the catastrophic event. Prompt image study for locations and types of ICH can predict outcomes.

Clinical implications of minimal residual disease monitoring by quantitative polymerase chain reaction in acute myeloid leukemia patients bearing nucleophosmin (NPM1) mutations.

To explore the validity and prognostic significance of minimal residual disease detection by quantitative polymerase chain reaction (qPCR) in patients of acute myeloid leukemia (AML) bearing Nucleophosmin (NPM1) mutations, we quantified mutants in 194 bone marrow samples from 38 patients with a median follow-up time of 20.6 months. Following induction chemotherapy, a median of 2.78 log decline in mutant copy number was observed. Relapse was always accompanied by significant increase of mutant numbers (P<0.001). After achieving complete remission (CR), the mutant copy number was significantly higher in patients with subsequent relapse than in those remaining in continuous CR (P<0.001). Presence of detectable mutants after treatment predicted relapse if no further chemotherapy was administered. Furthermore, the patients with any rise of mutant signals during serial follow-up had 3.2-fold increase of relapse risk compared to those with persistently low or undetectable signals (P<0.001). Patients who could achieve mutant reduction to <0.1% of internal control had significantly longer overall survival (OS) (P=0.004) and relapse-free survival (RFS) (P<0.001). Failure to achieve 2 logs of reduction after consolidation predicted shorter OS (P=0.01) and RFS (P=0.001). In conclusion, qPCR monitoring may have prognostic impact in AML patients with NPM1 mutations.

Overexpression of SOX4 correlates with poor prognosis of acute myeloid leukemia and is leukemogenic in zebrafish.

The SOX4 transcription factor is a key regulator of embryonic development, cell-fate decision, cellular differentiation and oncogenesis. Abnormal expression of SOX4 is related to malignant tumor transformation and cancer metastasis. However, no reports are available regarding the clinical significance of SOX4 in acute myeloid leukemia (AML) and the role of SOX4 in leukemogenesis. In the current study, we found that AML patients with low bone marrow (BM) SOX4 expression had higher remission rates and longer overall survival than those with high SOX4 expression, regardless of age, white blood cell count at diagnosis, karyotype profile and NPM1/FLT3-ITD status. To elucidate the role of SOX4 in leukemogenesis, we generated a transgenic zebrafish model that overexpressed human SOX4 in the myeloid lineage Tg(spi1-SOX4-EGFP). These transgenic zebrafish showed, at 5 months of age, increased myelopoiesis with dedifferentiation in kidney marrow. At 9 months of age, their kidney structure was significantly effaced and distorted by increased infiltration of myeloid progenitor cells. These results suggest that SOX4 is not only an independent prognostic factor of AML, but also an important molecular factor in leukemogenesis.

Clinico-biological significance of suppressor of cytokine signaling 1 expression in acute myeloid leukemia.

Suppressor of cytokine signaling 1 (SOCS1) protein, which encodes a member of signal transducers and activators of transcription-induced inhibitors, takes part in a negative regulation of cytokine signaling. The mechanism of SOCS1 in tumor carcinogenesis is complex and there have been no studies concerning the clinic-biologic implication of SOCS1 expression in acute myeloid leukemia (AML). Here, we first identified that higher bone marrow (BM) SOCS1 expression was closely associated with older age, FLT3-ITD, NPM1 and DNMT3A mutations, but negatively correlated with CEBPA mutation in patients with de novo AML. Compared to patients with lower SOCS1 expression, those with higher expression had lower complete remission rates and shorter overall survival. Further, higher expression of SOCS1 in the BM was an independent unfavorable prognostic factor irrespective of age, white blood cell, cytogenetics and gene mutations. Next, we generated zebrafish model overexpressing SOCS1 by spi1 promoter, which showed kidney marrow from adult SOCS1 zebrafish had increased myelopoiesis, myeloid progenitors and the kidney or spleen structure were effaced and distorted, mimicking leukemia phenotype. The SOCS1/FLT3-ITD double transgenic fish could further facilitate the leukemic process. The results indicate SOCS1 plays an important role in AML and its higher expression serves as a new biomarker to risk-stratify AML patients.

Prognostic significance of NPM1 mutation-modulated microRNA-mRNA regulation in acute myeloid leukemia.

Distinct microRNA (miRNA) and mRNA signatures were reported in nucleophosmin (NPM1)-mutated acute myeloid leukemia (AML). However, it remains unknown whether the mutation participates in the dynamic interaction between miRNA and mRNA. In this study, we aimed to investigate the role of NPM1 mutation in modulating miRNA-mRNA regulation (MMR). From the sample-paired miRNA/mRNA microarrays of 181 de novo AML patients, we found that MMR was dynamic and could be affected by NPM1 mutation. By a systematic framework, we identified 493 NPM1 mutation-modulated MMR pairs, where the strength of MMR was significantly attenuated in patients carrying NPM1 mutations, compared to those with wild-type NPM1. These miRNAs/mRNAs were associated with pathways implicated in cancer and known functions of NPM1 mutation. Such modulation of MMR was validated in two independent cohorts as well as in cells with different NPM1 mutant burdens. Furthermore, we showed that the regulatory strength of nine MMR pairs could predict patients' outcomes. Combining these pairs, a scoring system was proposed and shown to predict survival in discovery and validation data sets, independent of other known prognostic factors. Our study provides novel biological insights into the role of NPM1 mutation as a modulator of MMR, based on which a novel prognostic marker is proposed in AML.

Genetic alterations and their clinical implications in older patients with acute myeloid leukemia.

A number of patient-specific and leukemia-associated factors are related to the poor outcome in older patients with acute myeloid leukemia (AML). However, comprehensive studies regarding the impact of genetic alterations in this group of patients are limited. In this study, we compared relevant mutations in 21 genes between AML patients aged 60 years or older and those younger and exposed their prognostic implications. Compared with the younger patients, the elderly had significantly higher incidences of PTPN11, NPM1, RUNX1, ASXL1, TET2, DNMT3A and TP53 mutations but a lower frequency of WT1 mutations. The older patients more frequently harbored one or more adverse genetic alterations. Multivariate analysis showed that DNMT3A and TP53 mutations were independent poor prognostic factors among the elderly, while NPM1 mutation in the absence of FLT3/ITD was an independent favorable prognostic factor. Furthermore, the status of mutations could well stratify older patients with intermediate-risk cytogenetics into three risk groups. In conclusion, older AML patients showed distinct genetic alterations from the younger group. Integration of cytogenetics and molecular mutations can better risk-stratify older AML patients. Development of novel therapies is needed to improve the outcome of older patients with poor prognosis under current treatment modalities.

Comprehensive mutational analysis of primary and relapse acute promyelocytic leukemia.

Acute promyelocytic leukemia (APL) is a subtype of myeloid leukemia characterized by differentiation block at the promyelocyte stage. Besides the presence of chromosomal rearrangement t(15;17), leading to the formation of PML-RARA (promyelocytic leukemia-retinoic acid receptor alpha) fusion, other genetic alterations have also been implicated in APL. Here, we performed comprehensive mutational analysis of primary and relapse APL to identify somatic alterations, which cooperate with PML-RARA in the pathogenesis of APL. We explored the mutational landscape using whole-exome (n=12) and subsequent targeted sequencing of 398 genes in 153 primary and 69 relapse APL. Both primary and relapse APL harbored an average of eight non-silent somatic mutations per exome. We observed recurrent alterations of FLT3, WT1, NRAS and KRAS in the newly diagnosed APL, whereas mutations in other genes commonly mutated in myeloid leukemia were rarely detected. The molecular signature of APL relapse was characterized by emergence of frequent mutations in PML and RARA genes. Our sequencing data also demonstrates incidence of loss-of-function mutations in previously unidentified genes, ARID1B and ARID1A, both of which encode for key components of the SWI/SNF complex. We show that knockdown of ARID1B in APL cell line, NB4, results in large-scale activation of gene expression and reduced in vitro differentiation potential.

Direct comparisons of peripheral T-cell lymphoma with diffuse B-cell lymphoma of comparable histological grades--should peripheral T-cell lymphoma be considered separately?

Peripheral T-cell lymphoma (PTCL) forms a morphologically heterogeneous group of non-Hodgkin's lymphomas (NHL) with distinct immunophenotypes of mature T cells. Progress has been slow in defining specific clinicopathological entities to this particular group of NHL. In order to elucidate the specific characteristics of PTCL, a direct comparison of PTCL with a group of diffuse B-cell lymphomas (DBCL) was performed. Between June 1983 and December 1987, we studied 114 adults with NHL, using a battery of immunophenotyping markers. Adult T-cell leukemia/lymphoma, lymphoblastic lymphoma, mycosis fungoides/Sézary syndrome, follicular lymphoma, well-differentiated lymphocytic lymphoma, and true histiocytic lymphoma were excluded from this study since these are distinct clinicopathologic entities with well-recognized immunophenotypes. Of the remaining 75 patients, 70 who had adequate clinical information were analyzed, and of these, 34 were PTCL and 36 were DBCL. Classified according to the National Cancer Institute (NCI) Working Formulation (WF), 68% of PTCL and 31% of DBCL were high-grade lymphomas. Clinical and laboratory features were similar, except PTCL had a characteristic skin involvement and tended to present in more advanced stages with more constitutional symptoms. Induction chemotherapy was homogeneous in both groups, and complete remission rates were 62% for PTCL and 67% for DBCL. Patients with DBCL had a better overall survival than patients with PTCL, but the survival benefit disappeared after patients were stratified according to intermediate- or high-grade lymphoma. A subgroup of PTCL patients who had received less intensive induction chemotherapy was found to have a very unfavorable outcome. We conclude that (1) PTCL follows the general grading concept proposed in WF classification; (2) within a given intermediate or high grade, PTCL and DBCL respond comparably to treatment; (3) the intensity of induction chemotherapy has a crucial impact on the outcome of PTCL patients; and (4) with a few exceptions, the clinical and laboratory features of PTCL and DBCL are comparable.

Use of retinoic acids in the treatment of peripheral T-cell lymphoma: a pilot study.

PURPOSE: We have systemically analyzed, both in vitro and in vivo, the effect of 13-cis-retinoic acids (RA) on non-Hodgkin's lymphoma (NHL). METHODS: The in vitro growth-inhibitory effect of 13-cis-RA was examined in 11 (T cell, five; B cell, six) lymphoma cell lines by a tetrazolium colorimetric assay. A pilot clinical trial with oral 13-cis-RA 1 mg/kg/d was conducted in a selected group of 18 lymphoma patients, of whom 16 had failed to respond to at least one regimen of intensive chemotherapy. The in vitro and in vivo effects of 13-cis-RA were correlated with immunophenotypes, RA-induced changes of morphology, and patterns of DNA fragmentation of the lymphoma cells. RESULTS: Four of five T-lymphoma cell lines and none of six B-lymphoma cell lines were sensitive (concentration of 50% growth inhibition [IC50] < 1.5 microns) to 13-cis-RA (P = .015). In the clinical trial, five (two Ki-1, one angioinvasive type, one diffuse mixed cell, and one diffuse large cell) complete remissions and one (Ki1) partial remission were observed in 12 patients with peripheral T-cell lymphoma (PTCL), while none of six patients with B-cell lymphoma responded to 13-cis-RA. 13-cis-RA-induced cellular differentiation and apoptosis, as evidenced by the more mature morphology, characteristic nuclear condensation, and DNA ladder pattern signifying internucleosomal fragmentation, were demonstrated in the sensitive cell lines, as well as in the remitting lymphoma tissues. CONCLUSION: The 13-cis-RA appears to be active on lymphomas of T-lineage and their therapeutic indication may be extended to include some subtypes of PTCL. The mechanisms of action are related to differentiation and apoptosis of lymphoma cells. There appears to be no cross-resistance between 13-cis-RA and conventional chemotherapy.

Characterization of acute myeloid leukemia (AML) coexpressing lymphoid markers: different biologic features between T-cell antigen positive and B-cell antigen positive AML.

The clinical and biologic characteristics of acute myeloid leukemia (AML) with coexpression of lymphoid-associated antigens (Lym+ AML) were studied from 39 cases who represented 24% of 161 newly diagnosed de novo AML. Twenty-seven cases (16.8%) were positive for the expression of T-cell markers (T+ AML) and 12 (7.5%) for B-cell markers (B+ AML). Chromosomal abnormalities t(9;22)(q34;q11) and t/del(11)(q23), which were considered to be associated with acute leukemia coexpressing markers of more than one cell lineage, were detected in five and in four patients, respectively. There was no prognostic significance of B-cell or T-cell antigen expression in AML. Of 12 T+ AML cases in which cells were available for gene analysis, all showed germline configuration of immunoglobulin heavy chain and T-cell receptor beta chain genes, while seven of nine B+ AML showed rearrangements of either or both of the genes. Double labeling of the cells with myeloperoxidase and lymphoid markers demonstrated that individual blasts in all the five T+ AML tested were simultaneously expressing myeloperoxidase activity and CD7; however, most blasts in the three B+ AML studied expressed either myeloperoxidase activity or CD10, but not both. In eight of the nine T+ AML tested, the T-cell antigen-positive leukemic blasts were significantly decreased to less than 10%, after in vitro culture with the differentiation-inducing agent phorbol ester. B-cell markers remained positive (> or = 20%) on the cells in the two B+ AML who had the same study. These findings suggested that T+ AML and B+ AML might have different biologic features. Further studies on more patients are needed to clarify this point.

Extramedullary relapse after all-trans retinoic acid treatment in acute promyelocytic leukemia--the occurrence of retinoic acid syndrome is a risk factor.

All-trans retinoic acid (ATRA) is now a standard agent for remission induction of acute promyelocytic leukemia (APL). Recently, extramedullary relapse, which was a rare condition in APL patients after chemotherapy alone, was reported with an increased frequency after ATRA treatment. However, it is not yet clear whether ATRA truly increases the risk of extramedullary recurrence and what are the risk factors. In this study, three of 13 patients with recurrent APL after prior treatment of ATRA were found to have extramedullary involvement, compared with none in 11 recurrent patients previously treated with chemotherapy alone (estimated relative risk 2.100, 95% confidence interval 1.341-3.289). Furthermore, in the former group of patients, the development of retinoic acid (RA) syndrome during prior induction treatment was significantly associated with extramedullary involvement at relapse (three in five patients with RA syndrome vs none in eight without the syndrome, estimated relative risk 5.000, 95% confidence interval 1.448-17.271). In conclusion, ATRA may predispose APL patients to extramedullary involvement at relapse and the occurrence of RA syndrome is a risk factor for it. Further studies are needed to confirm these findings. It also remains to be clarified whether treatment modification is necessary in patients who develop RA syndrome during ATRA treatment.

Characterization of Philadelphia-chromosome-positive acute leukemia by clinical, immunocytochemical, and gene analysis.

Philadelphia chromosome (Ph') was detected at presentation in 10 out of 110 patients with acute lymphoblastic leukemia (ALL) and five of 168 patients with acute myelogenous leukemia (AML). Two other ALL patients who had studies at relapse were also included in the analyses. One of the 12 Ph'-positive (Ph+) ALL patients had simultaneous expression of myeloid-associated antigen on the leukemic blasts, while all the five AML patients coexpressed markers of lymphoid cells. Double labeling of the cells with myeloperoxidase and CD10 on three Ph+ AML cases showed that most leukemic blasts expressed either myeloperoxidase activity or CD10 but not both. Cross-lineage gene rearrangements of T-cell receptor (TCR) beta-chain gene were detected in three of the eight Ph+ ALL patients tested. All the four Ph+ AML cases studied showed immunoglobulin heavy chain gene rearrangements, and three of them also had simultaneous rearrangements of TCR beta-chain gene. The results revealed that Ph+ acute leukemia in this study belonged either to ALL or mixed lineage leukemia, and none was pure AML. This finding is contrary to that of acute blast crisis of chronic myelogenous leukemia in which the majority of patients had myeloid transformation. Rearrangements of bcr were detected in four of the 10 Ph+ ALL and three of the four Ph+ AML patients tested. No significant difference was noted in the clinical or hematologic manifestations among Ph+ leukemia with or without bcr rearrangements.

Clinical and biological characteristics of acute promyelocytic leukemia in Taiwan: a high relapse rate in patients with high initial and peak white blood cell counts during all-trans retinoic acid treatment.

Acute promyelocytic leukemia (APL) patients treated with all-trans retinoic acid (ATRA) and chemotherapy have been shown to have better outcome than those treated with conventional chemotherapy alone. However, the biological characteristics of leukemic cells and their clinical implications in patients treated with ATRA have not been well established. In this study, the biological and clinical features of 30 APL patients were reported. The risk factors for relapse and for occurrence of retinoic acid (RA) syndrome, which might cause morbidity or mortality of patients after ATRA treatment, were also analyzed. All patients showed 15;17 translocation by cytogenetic and/or gene analysis. Patients in this study had higher white blood cell (WBC) counts and a higher incidence of additional abnormalities than those from other areas. The ratio of long (L) form to short (S) form PML-RAR alpha fusion transcript was 1.8:1, a value lower than that of Latino patients but higher than that of Italians. Leukemic cells from four patients showed coexpression of T cell-associated antigen CD2 which was highly correlated with S form fusion transcript. Nine (36%) of the 25 patients treated with ATRA developed RA syndrome; all but one were successfully controlled by corticosteroid. Complete remission (CR) rate was 84%. Patients with high WBC counts tended to develop RA syndrome and had increased risk of relapse. Isochromosome for the long arm of the derivative chromosome 17, ider(17q), as an additional chromosomal abnormality was also associated with poor outcome in this study. In conclusion, APL in this study showed some different biological characteristics compared with those reported in other areas. High WBC count was a risk factor for relapse and development of RA syndrome after ATRA treatment. The prognostic implication of the presence of ider(17q) needs further clarification.

Clinical and biological implications of partial tandem duplication of the MLL gene in acute myeloid leukemia without chromosomal abnormalities at 11q23.

The clinical and biological features of acute myeloid leukemia (AML) with 11q23/MLL translocations are well known, but the characteristics of AML with partial tandem duplication of the MLL gene have not been explored comprehensively. In this study, MLL duplication was analyzed, in 81 AML patients without chromosomal abnormalities at 11q23, using Southern blotting, genomic DNA polymerase chain reaction (PCR), reverse-transcription PCR and complementary DNA sequencing. Nine patients showed partial tandem duplication of the MLL gene, including eight (12%) of the 68 with normal karyotype. Seven patients showed fusion of exon 6/exon 2 (e6/e2), one, combination of differentially spliced transcripts e7/e2 and e6/e2, and the remaining one, combination of e8/e2 and e7/e2. Among the patients with normal karyotype, children aged 1 to 15 showed a trend to higher frequency of MLL duplication than other patients (2/5 or 40% vs 6/62 or 10%, P = 0.102). The patients with tandem duplication of the MLL gene had a significantly higher incidence of CD11b expression on leukemic cells than did those without in the subgroup of patients with normal karyotype (75% vs 28%, P = 0.017). There were no significant differences in the expression of lymphoid antigens or other myeloid antigens between the two groups of patients. In adults, the patients with MLL duplication had a shorter median survival time than those without (4.5 months vs 12 months, P = 0.036). In conclusion, partial tandem duplication of the MLL gene is associated with increased expression of CD11b on leukemic blasts and implicates poor prognosis in adult AML patients. The higher frequency of MLL duplication in children older than 1 year, than in other age groups, needs to be confirmed by further studies.