High Levels Of Disease Research Articles

Relative importance of seed‐tuber and soilborne inoculum in causing black dot disease of potato

Controlled‐environment and field experiments were done to quantify the individual contribution of seed‐tuber and soilborne inoculum of Colletotrichum coccodes in causing black dot disease of potato tubers. Seed‐tuber and soilborne inocula of C. coccodes were quantified using an existing real‐time PCR assay and related to subsequent incidence and severity of disease. In four field trials, a controlled‐environment experiment and through the monitoring of 122 commercial crops, seed‐tuber inoculum was found to be relatively less important than soilborne inoculum in causing black dot, and the level of seed‐tuber inoculum did not significantly affect either the incidence or severity of disease or the percentage of progeny tubers deemed unmarketable. By contrast, soilborne inoculum had the potential to result in high levels of disease and the level of C. coccodes soil infestation (pg DNA g−1 soil) was found to have a significant effect. At soil infestation levels below 100 pg DNA C. coccodes g−1 soil, 7% of commercial crops had an incidence of black dot greater than 20%, increasing to 40% and 57% of crops at levels of 100–1000 pg g−1 and >1000 pg g−1 soil, respectively. These arbitrary threshold levels for soilborne inoculum related to disease risk are discussed. Interpretation of disease risk based on inoculum levels must, in the future, be informed by agronomic variables and potential control strategies.

Cardiovascular effects of ambient particulate air pollution exposure.

An association between high levels of air pollutants and human disease has been known for more than half a century. Air pollution is composed of a heterogeneous mixture of compounds including ozone (O3), carbon monoxide (CO), sulfur dioxide (SO2), nitrogen oxides (NOx), liquids, and particulate matter (PM). Substantial epidemiological evidence implicates air pollution, particularly PM, as a major risk factor with serious consequences on human health.1–3 Of particular interest in PM are the particles that are ≤10 μm in diameter (PM10) because they are the PM that ultimately enters the lungs.4 PM is further divided into coarse (10 to 2.5 μm; PM10–2.5), fine (<2.5 μm; PM2.5), and ultrafine (<0.1 μm; PM0.1) particles.1 These particles are composed of solid and liquid components that originate from vehicle exhaust, road dust, smokestacks, forest fires, windblown soil, volcanic emissions, and sea spray. Particle size, surface area, and chemical composition determine the health risk posed by PM. Particulate and gaseous pollutants coexist in the air and may induce adverse health effects, whereas compelling data implicate PM as a major perpetrator of various types of human disease. PM rarely exists by itself within the ambient environment because gaseous and semivolatile/volatile compounds (ie, aldehydes and polycyclic aromatic hydrocarbons) are constantly changing and interacting. Many of these vapor-phase compounds attach to the surface of PM and/or by themselves form secondary aerosol particles. Because of their small size, PM2.5 and PM0.1 are inhaled deeply into the lungs, with a portion depositing in the alveoli and entering the pulmonary circulation and presumably the systemic circulation. The adverse effects of PM on the cardiovascular system have been established in a series of major epidemiological and observational studies.5–9 Although life expectancy has been improved significantly since air pollution levels …

Preemptive alloimmune intervention in high-risk pediatric acute lymphoblastic leukemia patients guided by minimal residual disease level before stem cell transplantation

Relapse of pediatric acute lymphoblastic leukemia (ALL) remains the main cause of treatment failure after allogeneic stem cell transplantation (alloSCT). A high level of minimal residual disease (MRD) before alloSCT has been shown to predict these relapses. Patients at risk might benefit from a preemptive alloimmune intervention. In this first prospective, MRD-guided intervention study, 48 patients were stratified according to pre-SCT MRD level. Eighteen children with MRD level >or=1 x 10(-4) were eligible for intervention, consisting of early cyclosporine A tapering followed by consecutive, incremental donor lymphocyte infusions (n=1-4). The intervention was associated with graft versus host disease >or=grade II in only 23% of patients. Event-free survival in the intervention group was 19%. However, in contrast with the usual early recurrence of leukemia, relapses were delayed up to 3 years after SCT. In addition, several relapses presented at unusual extramedullary sites suggesting that the immune intervention may have altered the pattern of leukemia recurrence. In 8 out of 11 evaluable patients, relapse was preceded by MRD recurrence (median 9 weeks, range 0-30). We conclude that in children with high-risk ALL, immunotherapy-based regimens after SCT are feasible and may need to be further intensified to achieve total eradication of residual leukemic cells.

Interaction of Rhizoctonia solani and Rhizopus stolonifer Causing Root Rot of Sugar Beet.

In recent years, growers in Michigan and other sugar beet (Beta vulgaris) production areas of the United States have reported increasing incidence of root rot with little or no crown or foliar symptoms in sugar beet with Rhizoctonia crown and root rot. In addition, Rhizoctonia-resistant beets have been reported with higher levels of disease than expected. In examining beets with Rhizoctonia root rot in Michigan, over 50% of sampled roots had a second potential root rot pathogen, Rhizopus stolonifer. Growing conditions generally were not conducive to disease production by this pathogen alone, so we investigated the potential for interaction between these two pathogens. In greenhouse tests, four of five sugar beet varieties had more severe root rot symptoms when inoculated with both pathogens than when inoculated with either pathogen alone. This synergism occurred under conditions that were not conducive to disease production by R. stolonifer. Host resistance to Rhizoctonia crown and root rot reduced diseases severity, but was insufficient to control the disease when both pathogens were present. This raises concerns about correct disease diagnosis and management practices and indicates that a root rot complex may be important on sugar beet in Michigan.

Lipoprotein(a): From Molecules to Therapeutics

Lipoprotein (a) [Lp(a)] was discovered by Kare Berg in 1963 from the study of low-density lipoprotein genetic variants. Lp(a) contains a unique protein, apolipoprotein(a), which is linked to the Apo B-100 through a disulfide bond that gives it a great structural homology with plasminogen, and confers it atherogenic and atherothrombotic properties. Interest in Lp(a) has increased because an important association between high plasma levels of Lp(a) and coronary artery disease and cerebral vascular disorders has been demonstrated. Numerous case control studies have confirmed that hyper-Lp(a) is a risk factor for premature cardiovascular disease. Lp(a) is identified as a genetic trait with autosomal transmission, codified by one of the most studied polymorphic genes in humans. It has been demonstrated that variations in this gene are a major factor in the serum levels of Lp(a). Variations differ considerably between individuals and sex across populations. Various approaches to drug treatment using fibric acid derivatives, growth hormone, insulin-like growth factor-1, alcohol extracted soy protein, niacin, and exercise have been proven to decrease Lp(a) in high risk patients, but none has really been an effective therapeutic option for successfully reducing Lp(a) plasma levels.

Abstract 1799: Utilizing metformin to enhance the efficacy of androgen deprivation therapy in the treatment of prostate cancer

Abstract The incidence of prostate cancer varies dramatically by geographic location, with developed countries exhibiting significantly higher levels of disease. Some attribute this to the ‘Westernized lifestyle’ of high energy diets coupled with lack of physical activity and consequent obesity. Rising obesity levels have been mirrored by increased diagnoses of non-insulin dependent diabetes (NIDDM). Whilst evidence for a causal association between obesity or NIDDM, and prostate cancer is mixed, clear evidence exists that obese prostate cancer sufferers have higher levels of prostate cancer-specific mortality. This may be due to obesity or diabetes-induced hyperinsulinemia, causing upregulated pro-proliferative insulin/insulin-like growth factor signaling. Our group has previously reported the association between diet-induced hyperinsulinemia and enhanced prostate cancer tumor growth in a murine xenograft model. Prostate cancer treatment varies depending on the stage/grade of the presenting disease. However, androgen ablation therapy remains the treatment of choice for advanced disease. Metformin (an oral biguanide used to treat NIDDM) has been shown to possess anti-neoplastic properties in vitro and in vivo. Studies have also shown that metformin treated diabetics experience less cancer diagnoses and/or prostate cancer-specific mortality. We assessed the potential additive benefit of androgen ablation therapy (bicalutamide) in combination with metformin. Using MTT and clonogenic assays we assessed the effect of bicalutamide and/or metformin on cell proliferation rates in LNCaP, PC3, DU145 and PC3AR2 prostate cancer cell lines. Exposing the cell lines to micromolar concentrations of bicalutamide or millimolar concentrations of metformin resulted in significant dose-dependent reductions in cellular proliferation (p&amp;lt;0.0001). Combined treatment with bicalutamide and metformin caused a further 10-fold reduction in cell proliferation. This effect was pronounced in cell lines expressing functional androgen receptors. Combining bicalutamide and metformin significantly reduces prostate cancer cell proliferation rates, further than monotherapy alone. These preliminary results are being further evaluated to determine whether this positive interaction is additive or synergistic. We are also assessing the combination regimen in vivo using a murine xenograft model and are performing mechanistic studies to determine how bicalutamide and metformin interact. This combination regimen may potentially improve prostate-cancer specific survival via the direct anti-neoplastic properties described above. In addition, although not investigated here, metformin, within the combination treatment regimen may improve overall survival rates by reducing the risk of anti-androgen induced metabolic syndrome, and its consequent cardiovascular related mortality. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1799.

High frequency of immature cells at diagnosis predicts high minimal residual disease level in childhood acute lymphoblastic leukemia

Prognosis for children with acute lymphoblastic leukemia (ALL) has considerably improved, yet relapse still occurs in a significant proportion of patients. Conceivably, the most immature leukemia cells may be more resistant to therapy and initiate relapse. We studied 42 patients with childhood ALL treated according to the ALL-BFM 2000 protocol. At diagnosis, we determined the characteristic immunophenotype of the leukemic cells by flow cytometry and also investigated the expression of CD34 and CD38 to define a population of immunophenotypically immature cells (CD34 +/CD38 −). We then studied levels of minimal residual disease (MRD) after induction therapy (day 33) and after consolidation therapy (week 12). We found a significant, increasing correlation between the prevalence of CD34 +/CD38 − cells at diagnosis and MRD levels at day 33 and week 12. Our results suggest that the initial frequency of CD34 +/CD38 − cells may serve as a prognostic marker in pediatric ALL.

99 UTILIZING METFORMIN TO ENHANCE THE EFFICACY OF ANDROGEN DEPRIVATION THERAPY IN THE TREATMENT OF PROSTATE CANCER

INTRODUCTION AND OBJECTIVES: Prostate cancer (PCa) incidence varies dramatically by geographic location, with developed countries exhibiting significantly higher levels of disease. Some attribute this to the ‘Westernized lifestyle’ of high energy diets and limited physical activity with consequent obesity. Obesity and obesity-related diseases like diabetes, cause hyperinsulinemia, which upregulates pro-survival insulin/insulin-like growth factor signalling. Our previous work shows diet-induced hyperinsulinemia to enhance PCa tumor growth in vivo. Metformin, a treatment for diabetes, reduces hyperinsulinemia, and has recently been shown to exhibit anti-neoplastic properties. We assessed the potential additive benefit of combining a standard PCa treatment (androgen ablation therapy with bicalutamide) with metformin in vitro and in vivo. METHODS: Using clonogenic assays we assessed the effect of bicalutamide and/or metformin on colony formation rates in LNCaP, PC3, DU145 and PC3AR2 PCa cell lines. Western blot and cell cycle analyses were used to elucidate any mechanism of interaction between the two drugs in androgen receptor (AR) positive (LNCaP) and AR negative (PC3) cell lines. The combination treatment regimen was then assessed in vivo using a LNCaP murine xenograft model. RESULTS: Micromolar bicalutamide or millimolar metformin caused significant dose-dependent reduction in colony formation rates (p 0.001). Combination treatment further significantly reduced colony formation rates (p 0.005). The effect was more pronounced in AR positive cells. Western blot and cell cycle analyses suggested differing mechanisms of interaction in AR positive and negative cell lines. Following combination treatment LNCaP cells exhibited altered cell proliferation (decreased PCNA) and perturbed cell cycle kinetics (G1/S arrest). Conversely, PC3 cells showed evidence of enhanced apoptosis (increased BAX, decreased caspase 3 and phospho-Akt). Preliminary in vivo results show significantly diminished tumor growth in response to the combination treatment regimen (p 0.0001). CONCLUSIONS: Combining bicalutamide and metformin significantly reduces PCa cell colony formation rates further than either monotherapy. In AR positive cells this effect is mediated by reducing cellular proliferation rates, whereas in AR negative cells the combination treatment regimen promotes apoptosis. This combination drug regimen may potentially improve prostate-cancer specific survival via the direct anti-neoplastic properties outlined.

Vaccine Preventability of Meningococcal Clone, Greater Aachen Region, Germany

Emergence of serogroup B meningococci of clonal complex sequence type (ST) 41/44 can cause high levels of disease, as exemplified by a recent epidemic in New Zealand. Multiplication of annual incidence rates (3.1 cases/100,000 population) of meningococcal disease in a defined German region, the city of Aachen and 3 neighboring countries (Greater Aachen) prompted us to investigate and determine the source and nature of this outbreak. Using molecular typing and geographic mapping, we analyzed 1,143 strains belonging to ST41/44 complex, isolated from persons with invasive meningococcal disease over 6 years (2001-2006) from 2 German federal states (total population 26 million) and the Netherlands. A spatially slowly moving clone with multiple-locus variable-number tandem repeat analysis type 19, ST42, and antigenic profile B:P1.7-2,4:F1-5 was responsible for the outbreak. Bactericidal activity in serum samples from the New Zealand MeNZB vaccination campaign confirmed vaccine preventability. Because this globally distributed epidemic strain spreads slowly, vaccination efforts could possibly eliminate meningococcal disease in this area.

Unilateral nevoid telangiectasia—response to long-pulsed Nd:YAG laser and pulsed dye laser: a case report

Unilateral nevoid telangiectasia (UNT) is a rare disease characterized by punctuate and stellate telangiectasias that follow dermatomal distribution.1 Its etiology remains elusive; no standard treatment currently exists. We describe a 14-year-old Asian female (skin type IV) with UNT, who underwent treatment with long-pulsed 1064-nm Nd:YAG laser and 595-nm pulsed dye laser for her disease. The patient came to our clinic with linearly arranged, punctate telangiectasias over right side of back, shoulder, and arm (Figure 1). The lesions appeared at the age of 10. The diagnosis of UNT was made based on the clinical manifestations and telangiectasias in superficial dermis (as shown on a histologic exam done previously at another hospital). Angioma serpiginosum is an important differential diagnosis of UNT in this case. Three sessions of treatment with long-pulsed 1064-nm Nd:YAG laser (GentleYAG Laser; Candela Laser, Wayland, MA, USA) were given with parameters (fluence-spot sizepulse width) of 240 J/cm2-3 mm-10 ms (first week), 240 J/ cm2-3 mm-10 ms (second week), and 280 J/cm2-3 mm-10 ms (third week). The interval between each session was 4 weeks. However, there was only slight improvement. Histologic exam performed 2 weeks after the third session revealed marked telangiectasias in papillary dermis (Figure 2). Next, two sessions of pulsed dye laser with 595 nm wavelength (Vbeam Perfecta; Candela Laser) were given with parameters of 13 J/cm2-7 mm-40 ms (fluence-spot sizepulse width) for both sessions. Significant lightening of lesions (> 90%) was observed after the second session (Figure 3). The only adverse reaction was transient purpura that lasted for approximately 2 weeks. There was no hypoor hyper-pigmentation after treatment. There are two forms of UNT, the rarer congenital form and the more common acquired form.2 Telangiectasia develops during puberty in most of the acquired cases, as in our patient. Several reports point out the systemic association of acquired UNT, such as hyperestrogenemia and chronic liver disease.2 In out patient, there was no evidence of high serum level of estrogen or hepatic disease. Both long-pulsed 1064-nm Nd:YAG laser and pulsed dye laser have been shown to be effective in treating vascular lesions.3,4 Major et al3 reported good response with the former for facial and leg telangiectasias. However, it does not seem to be a good treatment modality for UNT for the current case. One possible explanation is that while the 1064-nm Nd:YAG laser beam tends to penetrate to deeper dermis, due to its long wavelength and lesser absorption Figure 1 Clinical picture before treatment.

Dissemination of Pseudomonas savastanoi pv. savastanoi populations and subsequent appearance of olive knot disease

Pseudomonas savastanoi pv. savastanoi (Psv) is the causal agent of olive knot disease. The bacterium survives epiphytically and gains ingress through new wounds where infections and colonization result in knot formation. The natural spread of the bacterium and the subsequent appearance of the disease in olive orchards is poorly understood. The aim of this study was to monitor Psv epiphytic populations in inoculated plants with knots versus non‐inoculated healthy trees within the same orchard over four years. Additionally, disease severity was measured in both inoculated and non‐inoculated control trees. Epiphytic Psv populations moved from inoculated to non‐inoculated trees, although average Psv populations were higher in inoculated trees. Olive knot severity increased over the course of the study in all treatments and cultivars, with all plants reaching a high level of disease by the end of the study. However, the delay in the onset of disease was longer in non‐inoculated than in inoculated trees. Molecular typing of Psv isolates recovered from non‐inoculated control trees confirmed that they were similar to the inoculated strain. These data demonstrate that Psv can move over short distances in olive orchards through dissemination of epiphytic bacteria and suggest a relationship between the presence of epiphytic Psv and the number of knots on trees.

Asbestos in Korean Buildings, Safety Concerns, and Sensible Risk Assessment

In spite of concerns by some, chrysotile or white asbestos continues to be used throughout much of the world although several countries have questioned its safety and a number of them have decided to ban its use for any purpose. The reason is largely because the commercial exploitation over a century ago was carried through with little regard for health and safety through ignorance of possible health effects. Poor working conditions with high airborne fibre levels produced a high level of disease. No effects were noted in people exposed to chrysotile at low fibre levels and recent studies have confirmed this lack of effect. However, concern regarding the early mistakes persists to the present time, the subject has become politicised and in 2007 the Korean government banned further use of chrysotile cement. This high level action affects the attitudes of the public, building owners, and occupiers. There is overwhelming evidence that low level exposure has no adverse health effects and that there is a practical threshold. Whether or not the Korean government ever rescinds the ban the fact remains that abatement and replacement of existing chrysotile materials because of a fear of very low level exposure is incompatible with sustainable building practices.

Evaluation of type I fusarium head blight resistance of wheat using non‐deoxynivalenol‐producing fungi

A series of experiments was conducted to determine whether type I resistance (resistance to initial infection) to fusarium head blight (FHB) in wheat could be assessed using fungal species/isolates that do not produce deoxynivalenol (DON), a mycotoxin critical to the spread of Fusarium graminearum in the wheat spike. It was shown that, while the non‐toxin‐producing species Microdochium nivale and M. majus could infect following spray inoculation of wheat spikes, they were unable to spread within the spike following point inoculation. However, although these species might reveal type I resistance, they are not highly pathogenic towards wheat. A nivalenol (NIV)‐producing isolate of F. graminearum caused high levels of disease following spray inoculation, but spread only very slowly within the spike and rarely induced bleaching above the point of inoculation. It is proposed that spray inoculation with an appropriate, aggressive, non‐DON‐producing FHB pathogen may be used to characterize type I resistance to complement point inoculation with a DON‐producing isolate to assess type II resistance (resistance to spread within the spike).

Impact of major gene resistance management for sunflower on fitness ofPlasmopara halstedii(downy mildew) populations

Changes in virulence of Plasmopara halstedii populations under different major gene (Pl) management strategies were studied over 5 years continuous cropping of one sunflower hybrid under netting cages. Strategies were monoculture of forms of the hybrid with 1 gene or with combinations of 2 genes, alternation of different genes, and mixtures of several different forms of the hybrid. Monoculture with single resistance genes led to loss of efficient resistance after 3 years, with high levels of disease and increased variability of the pathogen, whatever the Pl gene used. Combinations of genes, alternation and mixtures gave longer term control of downy mildew. In particular, combinations of resistance genes coming from both female and male parents of the hybrid (such that even impurities had a resistance gene) gave the best control and least variation in pathogen virulence. Results are discussed with the object of durable control of downy mildew by all methods available.

Integrating Planting Dates and Fungicide Applications for Managing White Mold of Dry Beans in Western Nebraska

White mold, caused by the soilborne fungus Sclerotinia sclerotiorum, is one of the most destructive diseases of common beans (Phaseolus vulgaris L.) and is greatly influenced by environmental conditions and certain agronomic practices. A 3-year study (2003 to 2005) evaluated planting date and thiophanate-methyl fungicide applications based on decision aids consisting of blue plate technique, sugar beet Cercospora leaf spot (CLS) disease forecasting model, and crop phenology (90% bloom). Overall yields were lower in 2003 and higher in 2005, and disease severity was greater in 2004. Planting dry beans in late June to early July resulted in higher levels of disease than planting in late May or mid-June in 2004. Late planting also resulted in lower yields and 100-seed weight in 2004 and 2005 than the early and mid-plantings. Compared to the control and CLS model, fungicide applications based on the blue plate and 90% bloom treatments reduced disease severity in 2004 and 2005, while also increasing 100-seed weight and yields in 2004. Accepted for publication 8 May 2010. Published 1 July 2010.

Distribution of Common Methylenetetrahydrofolate Reductase Gene Mutations in Patients with Obstructive Sleep Apnoea

Homocysteine levels have been investigated in patients with obstructive sleep apnoea syndrome (OSAS), a syndrome associated with a high level of comorbid cardiovascular disease (CVD). While significant increases in homocysteine levels have been observed in OSAS patients with CVD, no increases have been noted in OSAS patients without CVD. This study was designed to investigate the methylenetetrahydrofolate reductase (MTHFR) gene, which is essential for homocysteine metabolism and has been shown to have a causal role in the development of CVD. Eighty subjects, 30 diagnosed with OSAS by polysomnography and 50 controls (healthy volunteers with no symptoms of OSAS) were enrolled. Two mutations in the MTHFR gene were investigated using polymerase chain reactions and restriction fragment length polymorphisms. No significant differences were found in mean age, body mass index, homocysteine levels, or MTHFR allele or genotype distributions between patient and control groups.

Prognostic Significance of NOTCH1 and FBXW7 Mutations in Childhood T-Cell Acute Lymphoblastic Leukemia (T-ALL): Results From the EORTC Children Leukemia Group.

Abstract 909▪▪This icon denotes an abstract that is clinically relevant.T-ALL accounts for approximately 15% of childhood ALL. Despite major improvement of treatments, relapses still occur with dramatic prognosis. Efforts made in the past decade to understand T-ALL oncogenesis led to the identification of a number of oncogenes deregulated by genomic abnormalities, including TAL1, HOX11/TLX1, HOX11L2/TLX3, CALM-AF10, NUP214-ABL1, and MYB, some of them determining subtypes with distinct biological profiles. However, in EORTC trials, using BFM-derived protocols, these various genetic lesions have no prognostic impact, with the exception of a trend toward a favourable outcome for SIL-TAL1 fusion or HOX11 over expression (Cavé et al. 2004). Thus, risk-stratification remained based on early response to chemotherapy, as assessed by poor response to the (corticosteroid) prephase (PPR) and, in addition (58951 trial), on a high level (>10-2) of minimal residual disease (MRD) at completion of induction therapy. Hyperactivation of the NOTCH pathway by mutations of NOTCH1 or FBXW7 has been recently demonstrated in T-ALL. We investigated whether NOTCH1 and/or FBXW7 status could help to improve risk-stratification in T-ALL. We screened NOTCH1 and FBXW7 mutations by direct sequencing in 133 children with T-ALL enrolled in EORTC-CLG trials 58881 and 58951. Activating NOTCH1 mutations were found in 75 (56%) patients. Inactivating FBXW7 mutations were found in 20 (14%) patients, mostly in association with NOTCH1 mutations. Overall, 78 (59%) patients were considered NOTCH+ (NOTCH1 and/or FBXW7 mutated) whereas 55 (41%) were NOTCH- (NOTCH1 and FBXW7 wild type). NOTCH+ patients were distributed through all genetic subgroups. No significant relationships between NOTCH status and sex, age, WBC count, CNS or mediastinal involvement were observed. However, NOTCH+ had more often a cortical immunophenotype (53% vs 28%; p=0.02). NOTCH+ patients had a better early response to chemotherapy vs NOTCH- patients: lower PPR rate (20% vs 42%; p=0.02), and a lower incidence of high MRD level (13% (6/45) versus 30% (9/30); p=0.14). This led to less frequent switch to a very high risk (VHR) protocol for NOTCH+ versus NOTCH- patients (29% vs 49%, p=0.05). After a median follow-up of 4.6 years, 3 patients did not reach CR, 25 relapsed, 1 died in CR and 84 remained alive in CR; a total of 18 patients died. The outcome of NOTCH+ patients was similar to that of NOTCH- patients. The 5-yr EFS were 74% and 69% (p=0.8), respectively, and the 5-yr overall survival were 82% and 80% (p=0.7), respectively. However, prognostic importance of NOTCH status differed according to early response to treatment. In patients with a PPR, the NOTCH+ patients had a worse outcome than NOTCH- patients (5-yr EFS was 44% vs 58%; HR=1.54, p=0.43), whereas in non-PPR subgroup a reverse trend was observed (5-yr EFS was 83% vs 76%; HR=0.94, p=0.91). Similarly, in patients with high MRD levels the outcome was worse in NOTCH+ vs NOTCH- patients (5-yr EFS was 0% vs 47%, HR=11.7, p=0.03) whereas in MRD- patients the trend was reversed (5-yr EFS was 79% vs 71%, HR=0.88, p=0.83). Thus, although NOTCH1+ patients responded earlier and better to chemotherapy as compared to NOTCH1- patients, they did not show, overall, a better EFS. This was due to the poor outcome of NOTCH+ patients who had VHR features. In the German BFM trials, NOTCH1 mutations were also associated with lower rate of “poor response” to chemotherapy but this translated into a favourable outcome (see the ASH 2009 abstract of Kox et al.) NOTCH1- patients had a similar outcome in EORTC and BFM studies (5-yr EFS: 69% vs 74%) whereas NOTCH1+ patients had a lower 5-yr EFS in EORTC than in BFM studies (74% vs 87%). Noteworthy, in the EORTC trials the rate of isolated CNS relapses was quite high in NOTCH1+ patients (7.8%=6/77) as compared to NOTCH- patients (1.9%=1/53). Recently it was shown that NOTCH1 positively controls the expression of the chemokine receptor CCR7, an adhesion signal required for targeting T-ALL cells into the CNS (Buonamici et al. 2009). This may explain the higher propensity of NOTCH+ ALL to relapse in CNS. Although this is not the only difference in treatment between EORTC and BFM, the use of high dose methotrexate and intrathecal chemotherapy only, with omission of cranial irradiation prophylaxis in EORTC protocols, might have led to a suboptimal prevention of CNS relapses in NOTCH+ T-ALL, resulting in a lower EFS in EORTC trials as compared with German BFM in this group of patients. Disclosures:No relevant conflicts of interest to declare.

Patients with Early T-Cell Precursor (ETP) Acute Lymphoblastic Leukemia (ALL) Have High Levels of Minimal Residual Disease (MRD) at the End of induction—A Children's Oncology Group (COG) Study.

Abstract 9Current risk stratification algorithms in children with B-lineage ALL have facilitated the identification of subgroups with adverse outcomes that benefit from intensified therapy. However, many of the features that are highly prognostic of outcome in B-precursor ALL, such as the combination of age and white blood cell count (WBC) at diagnosis, have limited ability to predict outcome in T-ALL. In contrast, early response to induction therapy, as measured by bone marrow (BM) morphology at days 8, 15 or 29, and day 29 (end induction) BM MRD are highly predictive of outcome in both B-precursor and T-ALL. Coustan-Smith and colleagues (Lancet Oncology 10:147-156 2009) have recently identified a subset of children with ETP ALL that have an extremely high risk of induction failure or relapse. The ETP ALL blasts exhibit stem cell-like features as defined by the presence of antigens seen on early progenitors including CD117, CD34, HLA-DR and/or CD13/33, the absence of antigens seen on later stage immature T cells including CD1a and CD8, and decreased to absent expression of the early T cell antigen CD5.We analyzed patients enrolled in current generation COG ALL trials, including patients with B-precursor ALL treated on AALL0232 (high risk, n=2129) or AALL0331 (standard risk, n=3747), and 416 patients with T-ALL enrolled on AALL03B1. Clinical features including age, WBC, gender, and CNS status were compared between ETP-positive (n=25) and –negative (n=391) T-ALL patients. We also compared response to four weeks of induction therapy (prednisone, vincristine, PEG-asparaginase, and daunorubicin) as measured by day 15 and 29 BM morphology and day 29 BM MRD determined by flow cytometry. Twenty-five of 416 (6%) T-ALL patients had an ETP phenotype. The ETP-positive patients were older and presented with a lower white blood cell count than the ETP-negative patients (see Table). There was no difference in the gender distribution or the presence of CNS disease at diagnosis between the two groups. Strikingly, the ETP-positive patients had a dramatically inferior early response to therapy with 100% having ≥ 0.01% day 29 MRD (vs. 46% of ETP-negative T-ALL and 23.4% of precursor B-ALL) and 74% having ≥ 1% day 29 MRD (vs. 21% of ETP-negative T-ALL and 5% of precursor B-ALL). These results confirm the poor response of ETP T-ALL and suggest that novel treatment strategies are warranted in this patient subgroup. Disclosures:No relevant conflicts of interest to declare.ETP+ETP−p-valueAge 10+ years (n1 =25, n2 =391)76%45%0.0032WBC ≥ 50,000/mcl (n1 =23, n2 =371)22%63%0.0002Gender (Males) (n1 =25, n2 =391)60%77%0.09CNS status (CNS3) (n1 =23, n2 =368)0%7%0.39Day 15 BM ≥ 5% blasts (n1 =20, n2 =312)75%21%< 0.0001Day 29 BM ≥ 5% blasts (n1 =18, n2 =305)17%4%0.0516Day 29 BM MRD ≥ 0.01% (n1 =19, n2 =303)100%46%< 0.0001Day 29 BM MRD ≥ 1% (n1 =19, n2 =304)74%21%< 0.0001Day 29 BM MRD ≥ 10% (n1 =19, n2 =303)21%7%0.043

Status of Minimal Residual Disease Determines Outcome of Autologous HSCT in Adults with High-Risk Acute Lymphoblastic Leukemia.

Abstract 2321Poster Board II-298The role of autologous hematopoietic stem cell transplantation (autoHSCT) in the treatment of adult acute lymphoblastic leukemia (ALL) is a subject of controversies as several prospective studies failed to prove its advantage over maintenance chemotherapy. Those studies, however, did not take into account the status of minimal residual disease (MRD), which is now recognized a potent predictor for relapse among patients treated with conventional-dose chemotherapy. The goal of this analysis was to determine the impact of MRD on outcome of autoHSCT.Data on 123 autoHSCT recipients collected from 6 study groups cooperating in the European Leukemia Net were analyzed. Median age of 77 B-lineage and 46 T-lineage high-risk ALL patients was 31 (16-59) years. Ph+ ALL was recognized in 20 cases. All patients were in first complete remission (CR) lasting 6 (1.5-22) months. Peripheral blood was used as a source of stem cells in 67 patients whereas bone marrow, in 56 cases. Conditioning was based on chemotherapy alone (n=76) or total body irradiation (n=47). MRD was evaluated in bone marrow with the use of either multiparametric flow cytometry (n=79) or molecular techniques (n=44). MRD level of 0.1% bone marrow cells was used as a cut-off point for the purpose of this study. At the time of autoHSCT MRD was &0.1% in 93 patients and ≧0.1% in 30 cases.With the median follow up of 5 years, the probability of leukemia-free survival (LFS) at 5 years for the whole group equaled 48% (+/-5). Three patients died of transplantation-related complications. The LFS rate was significantly higher for patients with the MRD level at transplantation &0.1% compared to those with MRD ≧0.1% (57% vs. 19%, p=0.0002). The difference was particularly pronounced for peripheral blood HSCT (66% vs. 20%, p=0.0006) and for T-lineage ALL (62% vs. 8%, p=0.001). In a multivariate analysis adjusted for other potential prognostic factors (age, CR duration, Ph+ ALL, immunophenotype, source of stem cells, type of conditioning), the MRD status &0.1% remained the only independent factor associated with increased LFS (HR=2.5, p=0.0009).CONCLUSIONS: MRD status is the most important predictor for LFS after autoHSCT in adults with ALL. More than half of patients with high risk disease and low MRD level at the time of transplantation may be cured. This observation may contribute to re-evaluation of the role of autoHSCT in the therapy of adult ALL. Disclosures:No relevant conflicts of interest to declare.

High Progenitor Cell Frequency at Diagnosis Predicts High Minimal residual Disease Level in Childhood ALL.

Abstract 4705Acute lymphoblastic leukemia (ALL) as the most frequent childhood malignancy exhibits a favorable prognosis, yet a significant proportion of patients suffer a relapse. Comparable to acute myeloblastic leukemia, immature leukemic cells may be resistant to therapy and initiate a new population of leukemic cells. 42 patients with childhood ALL treated according to the ALL-BFM 2000 protocol were included in the present study. We determined an aberrant immunophenotype of the leukemic population at diagnosis and investigated the expression of CD34, CD38 and CD45 in leukemic blasts. The fraction of immature leukemic cells defined by CD34+/CD38-/CD45low at time of diagnosis as well as level of minimal residual disease (MRD) at day 33 and day 80 was determined. This is the first study to show a significant correlation of the initial fraction of immature leukemic cells with minimal residual disease levels at day 33 and day 80 in childhood ALL. Thus the initial level of this CD34+/CD38-/CD45low population may serve as marker for adverse prognosis in pediatric ALL. Disclosures:No relevant conflicts of interest to declare.