Potential methylation-regulated genes and pathways in hepatocellular neoplasm, not otherwise specified

Background and Aims

The molecular basis of hepatocellular neoplasm, not otherwise specified (HCN-NOS) is unknown. We aimed to identify gene expression patterns, potential methylation-regulated genes and pathways that characterize the tumor, and its possible relationship to hepatoblastoma and hepatocellular carcinoma (HCC).

Approach & Results

Parallel genome-wide profiling of gene expression (RNAseq) and DNA methylation (EPIC850) was performed on 4 pairs of pre-treatment HCN-NOS tumors and adjacent non-tumor controls. 2530 significantly differentially expressed genes (DEGs) were identified between tumors and controls. Many of these DEGs were associated with hepatoblastoma and/or HCC. Analysis Match in Ingenuity Pathway Analysis determined that the gene expression profile of HCN-NOS was unique but significantly similar to that of both hepatoblastoma and HCC. A total of 27,195 CpG sites (CpGs) were significantly differentially methylated (DM) between tumors and controls, with a global hypomethylation pattern and predominant CpG island hypermethylation in promotor regions. Aberrant DNA methylation predominated in Developmental Process and Molecular Function Regulator pathways. Embryonic stem cell pathways were significantly enriched. In total, 1055 aberrantly methylated (at CpGs) and differentially expressed genes were identified, including 25 upstream regulators and sixty-one potential CpG island methylation-regulated genes. Eight methylation-regulated genes (TCF3, MYBL2, SRC, HMGA2, PPARGC1A, SLC22A1, COL2A1 and MYCN) had highly consistent gene expression patterns and prognostic value in patients with HCC, based on comparison to publicly available datasets.

Conclusions

HCN-NOS has a unique, stem-cell like gene expression and DNA methylation profile related to both hepatoblastoma and HCC but distinct therefrom. Further, 8 methylation-regulated genes associated with prognosis in HCC were identified.

Randomised controlled trial comparing two group-based exercise programmes (team sport vs circuit training) on men's health: study protocol

Introduction

Physical activity promotes physical, psychological and social health. Despite this, almost half of middle-aged (35–54 years) Australian men are insufficiently active. Exercise adherence is increased with social interaction in a group setting. Team sport can leverage the power of groups and has shown to be more intrinsically motivating than discrete exercise modes. Evaluation of the effect of team sport compared with traditional group exercise on health, particularly psychological and social health, and physical activity levels of middle-aged men is limited. This study aims to compare the effects of team sport participation and group circuit training on physical activity levels and health in insufficiently active middle-aged men.

Methods and analysis

In this parallel randomised controlled trial, n=128 men aged 35–54 years will complete a 12-week team sport or group circuit exercise programme. Participants must self-report to not be meeting Australian physical activity guidelines or participating in team sport before recruitment. Health-related quality of life, exercise motivation, psychological needs satisfaction, sleep and physical activity levels (accelerometry), blood lipids, glucose and metabolic syndrome risk score will be assessed at baseline, end of the programme and 12 weeks follow-up. Linear mixed effect models will be used.

Ethics and dissemination

The study has received ethical approval from the University of South Australia’s Human Research Ethics Committee (Ethics Protocol 203274). Study results will be disseminated via publication in disciplinary-specific journals, conference presentations, and as part of a Doctoral thesis.

Trial registration number

ANCTRN12621000483853.

Effect of a 12-Week Almond-Enriched Diet on Biomarkers of Cognitive Performance, Mood, and Cardiometabolic Health in Older Overweight Adults

Long term nut consumption is associated with reduced risk of coronary heart disease and better cognitive function. This study examined supplementing habitual diets with almonds or carbohydrate-rich snack foods (providing 15% energy) on biomarkers of cardiovascular and metabolic health, mood and cognitive performance. Participants (overweight/obese, 50-80 years) were randomised to an almond-enriched diet (AED) or isocaloric nut-free diet (NFD) for 12 weeks. Body weight, blood lipids, glucose, insulin, blood pressure (BP), arterial stiffness, cell adhesions molecules, C reactive protein (CRP), mood, and cognitive performance (working memory primary outcome), dietary profiles and energy intake/expenditure were measured at baseline and Week 12 in 128 participants (n = 63 AED, n = 65 NFD). Compared with NFD, AED was associated with altered macro and micronutrient profiles, but no differences in energy intake or expenditure. The AED significantly reduced triglycerides and SBP but there were no other changes in cardiometabolic biomarkers, mood, or cognitive performance. The inclusion of almonds in the diet improves aspects of cardiometabolic health without affecting cognitive performance or mood in overweight/obese adults.

Long-Chain Omega-3 Fatty Acid Intake Is Associated with Age but not Cognitive Performance in an Older Australian Sample

BACKGROUND

Long-chain omega-3 polyunsaturated fatty acids (LCn-3 PUFA) are essential nutrients and may be capable of delaying age-related cognitive decline. However, previous studies indicate that Australians are not meeting recommendations for LCn-3 PUFA intake. The current study therefore examined LCn-3 PUFA intake in an older Australia sample, as well as associations between LCn-3 PUFA intake and cognitive function.

METHODS

Cross-sectional data were collected from 90 adults aged 50 to 80 years. LCn-3 PUFA intake was assessed using a food frequency questionnaire and red blood cell fatty acid profiles were used to calculate the Omega-3 Index (RBC n-3 index). Cognitive function was measured using Addenbrooke's Cognitive Examination-III.

RESULTS

Positive associations were observed between age and RBC n-3 index (b=0.06, 95% CI: 0.01 - 0.10, P=0.01), and age and LCn-3 PUFA intake from fish oil capsules (b=17.5, 95% CI: 2.4 - 32.5 mg/day, P=0.02). When adjusting for LCn-3 PUFA from fish oil capsules, the association between age and RBC n-3 index was no longer significant. No associations were observed between LCn-3 PUFA intake and cognitive function.

CONCLUSION

LCn-3 PUFA and fish oil consumption increased with age in this sample of older Australians, particularly due to supplement intake. However, LCn-3 PUFA intake was not associated with cognitive function.

Comparison of two low-fat diets, differing in protein and carbohydrate, on psychological wellbeing in adults with obesity and type 2 diabetes: a randomised clinical trial

Background

Although higher-protein diets (HP) can assist with weight loss and glycemic control, their effect on psychological wellbeing has not been established. The objective of this study was to compare the effects of a HP and a higher-carbohydrate diet (HC), combined with regular exercise, on psychological wellbeing both during weight loss (WL) and weight maintenance phases (WM).

Methods

In a parallel RCT, 61 adults with T2D (mean ± SD: BMI 34.3 ± 5.1 kg/m², aged 55 ± 8 years) consumed a HP diet (29% protein, 34% carbohydrate, 31% fat) or an isocaloric HC diet (21%:48%:24%), with moderate intensity exercise, for 12 weeks of WL and 12 weeks of WM. Secondary data evaluating psychological wellbeing was assessed using: Problems Areas in Diabetes (PAID); Diabetes-39 Quality of Life (D-39); Short Form Health Survey (SF-36); Perceived Stress Scale-10 (PSS-10) and the Leeds Sleep Evaluation Questionnaire (LSEQ) at Weeks 0, 12 and 24 and evaluated with mixed models analysis.

Results

Independent of diet, improvements for PAID; D-39 diabetes control; D-39 severity of diabetes; SF-36 physical functioning and SF-36 general health were found following WL (d = 0.30 to 0.69, P ≤ 0.04 for all) which remained after 12 weeks of WM. SF-36 vitality improved more in the HP group (group x time interaction P = 0.03). Associations were seen between HbA1c and D-39 severity of diabetes rating (r = 0.30, P = 0.01) and SF-36 mental health (r = − 0.32, P = 0.003) and between weight loss and PAID (r = 0.30, P = 0.01).

Conclusion

Several improvements in diabetes-related and general psychological wellbeing were seen similarly for both diets following weight loss and a reduction in HbA1c with most of these improvements remaining when weight loss was sustained for 12 weeks. A HP diet may provide additional increases in vitality.

Trial registration

The trial was prospectively registered with the Australian New Zealand Clinical Trials Registry (ACTRN 12613000008729) on 4 January 2013.

Long-term effects of very low-carbohydrate and high-carbohydrate weight-loss diets on psychological health in obese adults with type 2 diabetes: randomized controlled trial

BACKGROUND/OBJECTIVE

Very low-carbohydrate, high-fat (LC) diets are used for type 2 diabetes (T2DM) management, but their effects on psychological health remain largely unknown. This study examined the long-term effects of an LC diet on psychological health.

METHODS

One hundred and fifteen obese adults [age: 58.5 ± 7.1 years; body mass index: 34.6 ± 4.3 kg m(-2) ; HbA1c : 7.3 ± 1.1%] with T2DM were randomized to consume either an energy-restricted (~6 to 7 MJ), planned isocaloric LC or high-carbohydrate, low-fat (HC) diet, combined with a supervised exercise programme (3 days week(-1) ) for 1 year. Body weight, psychological mood state and well-being [Profile of Mood States (POMS), Beck Depression Inventory (BDI) and Spielberger State Anxiety Inventory (SAI)] and diabetes-specific emotional distress [Problem Areas in Diabetes (PAID) Questionnaire] and quality of life [QoL Diabetes-39 (D-39)] were assessed.

RESULTS

Overall weight loss was 9.5 ± 0.5 kg (mean ± SE), with no difference between groups (P = 0.91 time × diet). Significant improvements occurred in BDI, POMS (total mood disturbance and the six subscales of anger-hostility, confusion-bewilderment, depression-dejection, fatigue-inertia, vigour-activity and tension-anxiety), PAID (total score) and the D-39 dimensions of diabetes control, anxiety and worry, sexual functioning and energy and mobility, P < 0.05 time. SAI and the D-39 dimension of social burden remained unchanged (P ≥ 0.08 time). Diet composition had no effect on the responses for the outcomes assessed (P ≥ 0.22 time × diet).

CONCLUSION

In obese adults with T2DM, both diets achieved substantial weight loss and comparable improvements in QoL, mood state and affect. These results suggest that either an LC or HC diet within a lifestyle modification programme that includes exercise training improves psychological well-being.

Adiposity is related to decrements in cardiorespiratory fitness in obese and normal-weight children

BACKGROUND

Obese children are typically less physically active than their normal-weight peers and are often assumed to be 'unfit'.

OBJECTIVE

Investigate the relationships between adiposity, physical activity levels and cardiorespiratory fitness (CRF) in obese and normal-weight children. A secondary aim was to examine obese/normal-weight differences in CRF.

METHODS

Obese (N = 107) and normal-weight (N = 132) 10-13-year-olds participated. Fat-free mass (FFM), percent fat, physical activity and peak oxygen uptake (VO2peak ) were assessed. Analyses were adjusted for socioeconomic status (SES).

RESULTS

Higher percent fat was inversely associated with VO2peak normalized for mass (r = -0.780, P < 0.001) even after controlling for physical activity (r = -0.673, P < 0.001). While higher percent fat was also inversely associated with VO2peak normalized for FFM, this was only significant in males (r = -0.247, P = 0.004) and did not persist after controlling for physical activity (r = -0.059 P = 0.526). Compared with normal-weight children, obese children had higher absolute VO2peak , lower VO2peak corrected for mass (P ≤ 0.009) and lower VO2peak corrected for FFM (P = 0.041) that did not persist after controlling for SES (P = 0.086).

CONCLUSION

Obesity-related inefficiencies in CRF were evident. Higher adiposity was associated with poorer CRF relative to mass, irrespective of physical activity levels. However, low physical activity levels may be responsible for associations between adiposity and CRF relative to FFM seen in boys, indicating the importance of encouraging physical activity.

Steroidal contraceptive use is associated with lower bone mineral density in polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a common condition affecting reproductive-aged women with features including hyperandrogenism and menstrual irregularity frequently treated with hormonal steroidal contraceptives. Women with PCOS appear to have lower bone mineral density (BMD). While steroidal contraceptives may positively affect bone health, their effect on BMD in PCOS is not known. The aim of this study was to assess BMD in women with PCOS according to recent contraceptive use. A cross-sectional analysis of 95 pre-menopausal overweight or obese sedentary women with PCOS [age 29.4 ± 6.4 years, body mass index (BMI) 36.1 ± 5.3 kg/m(2)] who either recently took steroidal contraceptives (ceased 3 months prior) or were not taking steroidal contraceptives was conducted. Clinical outcomes included BMD, anthropometry, insulin, glucose, reproductive hormones, dietary intake and vitamin use. BMD was significantly lower for women who used contraceptives compared to those who did not (mean difference 0.06 g/cm(2) 95 % confidence interval -0.11, -0.02, p = 0.005). In regression models, lower BMD was independently associated with contraceptive use (β = -0.05, 95 % CI -0.094, -0.002, p = 0.042), higher testosterone (β = -0.03, 95 % CI -0.05, -0.0008, p = 0.043) and lower BMI (β = 0.006, 95 % CI 0.002, 0.01, p = 0.007) (r (2) = 0.22, p = 0.001 for entire model). We report for the first time that overweight and obese women with PCOS with recent steroidal contraceptive use had lower BMD in comparison to non-users independent of factors known to contribute to BMD. Whether this observation is directly related to steroidal contraceptive use or other factors requires further investigation.

A randomised trial comparing low-fat diets differing in carbohydrate and protein ratio, combined with regular moderate intensity exercise, on glycaemic control, cardiometabolic risk factors, food cravings, cognitive function and psychological wellbeing in adults with type 2 diabetes: Study protocol

BACKGROUND

Hypocaloric low-fat diets, high in protein with moderate carbohydrate (HP) can enhance weight loss, improve glycaemic control and improve cardiometabolic health risk factors in type 2 diabetes mellitus (T2DM). However, it is unclear whether the metabolic benefits observed during weight loss are sustained during energy-balance and weight maintenance. Furthermore, there is a lack of evidence regarding the effect of HP diets on food cravings, cognitive function and psychological wellbeing in T2DM, despite carbohydrate food cravings, cognitive impairment and depression being associated with hyperglycaemia.

METHODS/DESIGN

Overweight/obese adults with T2DM were randomised to consume either a HP diet (n=32, ~32% protein, 33% carbohydrate, 30% fat) or a higher-carbohydrate diet (HC, n=29, ~22% protein, 51% carbohydrate, 22% fat) for 24 weeks with 30 min of moderate intensity exercise five days/week for the study duration. There were 2 phases: a 12 week weight loss phase followed by a 12 week weight maintenance phase. Primary outcome was glycaemic control (glycosylated haemoglobin; HbA1c). Secondary outcomes were cardiometabolic risk factors (body composition, fasting blood pressure, blood lipids, glucose, insulin and C-reactive protein), food cravings, cognitive function (memory; psychomotor and executive function and psychological well-being. Outcomes were measured at baseline and the end of each 12-week intervention phase. Data will be analysed as intention-to-treat using linear mixed effects models.

CONCLUSION

This study will examine the effects of two dietary interventions on health outcomes in T2DM during weight loss and notably following weight maintenance where there is a paucity of evidence.

Are the dietary guidelines for meat, fat, fruit and vegetable consumption appropriate for environmental sustainability? A review of the literature

This paper reviews the current literature around the environmental impacts of dietary recommendations. The focus of the review is on collating evidence relating to environmental impacts of the dietary advice found in the World Health Organisation guidelines, and environmental impact literature: reducing the consumption of fat, reducing the consumption of meat-based protein and animal-based foods, and increasing the consumption of fruit and vegetables. The environmental impact of reducing dietary fat intake is unclear, although reducing consumption of the food category of edible fats and oils appears to have little impact. However most, but not all, studies support environmental benefits of a reduced consumption of animal-based foods and increased consumption of fruit and vegetables. In general, it appears that adhering to dietary guidelines reduces impact on the environment, but further study is required to examine the environmental impacts of animal-based foods, and fruit and vegetable intake in depth.

Day-to-day physical functioning and disability in obese 10- to 13-year-olds

What is already known about this subject? Compared with their healthy-weight peers, children with obesity have; impaired physical health-related quality of life reduced physical activity levels reduced capacity to perform certain weight-bearing tasks in field-based fitness tests What this study adds? First investigation of obesity-related disability in children using the International Classification for Functioning, Disability and Health framework for Children and Youth. Obesity in children appears to be associated with disability impacting basic locomotor skills and physical health-related quality of life. Children's participation in key life areas related to physical functioning appears to be minimally impacted by obesity.

OBJECTIVE

The aim of this study was to investigate whether obesity is related to impaired day-to-day physical functioning and disability in children.

METHODS

An observational case-control study was conducted in three Australian states. Obese (n = 107) and healthy-weight (n = 132) 10- to 13-year-olds (132 male, 107 female) were recruited via media advertisements. Assessment of body composition (dual energy X-ray absorptiometry), locomotor capacity (six-minute walk test [6MWT], timed up and down stairs test [TUDS] and timed up and go [TUG]) and child-reported physical health-related quality of life (HRQoL) were undertaken. Participants wore an accelerometer for 8 days and completed two use-of-time telephone interviews to assess participation in key life areas.

RESULTS

Compared with their healthy-weight counterparts, obese children had lower physical HRQoL scores (P < 0.01) and reduced locomotor capacity (TUDS z-score, TUG and 6MWT; P < 0.01). Higher percent body fat was significantly related to lower physical HRQoL scores (r = -0.48, P < 0.01), slower performance times for the TUDS and TUG (r = 0.59 and 0.26 respectively, P < 0.01), shorter 6MWT distances (r = -0.51, P < 0.01) and reduced time spent in community participation activities (r = -0.23, P < 0.01).

CONCLUSIONS

As anticipated, obesity appears to undermine physical functioning in children, including the capacity to perform basic locomotor skills yet, unexpectedly, participation in key life areas related to physical functioning appeared largely unaffected.

The effect of diet and exercise on markers of endothelial function in overweight and obese women with polycystic ovary syndrome

BACKGROUND

Women with polycystic ovary syndrome (PCOS) present with vascular abnormalities, including elevated markers of endothelial dysfunction. There is limited evidence for the effect of lifestyle modification and weight loss on these markers. The aim of this study was to determine if 20 weeks of a high-protein energy-restricted diet with or without exercise in women with PCOS could improve endothelial function.

METHODS

This is a secondary analysis of a subset of 50 overweight/obese women with PCOS (age: 30.3 ± 6.3 years; BMI: 36.5 ± 5.7 kg/m(2)) from a previous study. Participants were randomly assigned by computer generation to one of three 20-week interventions: diet only (DO; n = 14, ≈ 6000 kJ/day), diet and aerobic exercise (DA; n = 16, ≈ 6000 kJ/day and five walking sessions/week) and diet and combined aerobic-resistance exercise (DC; n = 20, ≈ 6000 kJ/day, three walking and two strength sessions/week). At Weeks 0 and 20, weight, markers of endothelial function [vascular cell adhesion molecule-1 (sVCAM-1), inter-cellular adhesion molecule-1 (sICAM-1), plasminogen activator inhibitor-1 (PAI-1) and asymmetric dimethylarginine (ADMA)], insulin resistance and hormonal profile were assessed.

RESULTS

All three treatments resulted in significant weight loss (DO 7.9 ± 1.2%, DA 11.0 ± 1.6%, DC 8.8 ± 1.1; P < 0.001 for time; P = 0.6 time × treatment). sVCAM-1, sICAM-1 and PAI-1 levels decreased with weight loss (P≤ 0.01), with no differences between treatments (P ≥ 0.4). ADMA levels did not change significantly (P = 0.06). Testosterone, sex hormone-binding globulin and the free androgen index (FAI) and insulin resistance also improved (P < 0.001) with no differences between treatments (P ≥ 0.2). Reductions in sVCAM-1 were correlated to reductions in testosterone (r = 0.32, P = 0.03) and FAI (r = 0.33, P = 0.02) as well as weight loss (r= 0.44, P = 0.002). Weight loss was also associated with reductions in sICAM-1 (r= 0.37, P = 0.008).

CONCLUSIONS

Exercise training provided no additional benefit to following a high-protein, hypocaloric diet on markers of endothelial function in overweight/obese women with PCOS.

Proximal correlates of metabolic phenotypes during 'at-risk' and 'case' stages of the metabolic disease continuum

OBJECTIVE

To examine the social and behavioural correlates of metabolic phenotypes during 'at-risk' and 'case' stages of the metabolic disease continuum.

DESIGN

Cross-sectional study of a random population sample.

PARTICIPANTS

A total of 718 community-dwelling adults (57% female), aged 18-92 years from a regional South Australian city.

MEASUREMENTS

Total body fat and lean mass and abdominal fat mass were assessed by dual energy x-ray absorptiometry. Fasting venous blood was collected in the morning for assessment of glycated haemoglobin, plasma glucose, serum triglycerides, cholesterol lipoproteins and insulin. Seated blood pressure (BP) was measured. Physical activity and smoking, alcohol and diet (96-item food frequency), sleep duration and frequency of sleep disordered breathing (SDB) symptoms, and family history of cardiometabolic disease, education, lifetime occupation and household income were assessed by questionnaire. Current medications were determined by clinical inventory.

RESULTS

36.5% were pharmacologically managed for a metabolic risk factor or had known diabetes ('cases'), otherwise were classified as the 'at-risk' population. In both 'at-risk' and 'cases', four major metabolic phenotypes were identified using principal components analysis that explained over 77% of the metabolic variance between people: fat mass/insulinemia (FMI); BP; lipidaemia/lean mass (LLM) and glycaemia (GLY). The BP phenotype was uncorrelated with other phenotypes in 'cases', whereas all phenotypes were inter-correlated in the 'at-risk'. Over and above other socioeconomic and behavioural factors, medications were the dominant correlates of all phenotypes in 'cases' and SDB symptom frequency was most strongly associated with FMI, LLM and GLY phenotypes in the 'at-risk'.

CONCLUSION

Previous research has shown FMI, LLM and GLY phenotypes to be most strongly predictive of diabetes development. Reducing SDB symptom frequency and optimising the duration of sleep may be important concomitant interventions to standard diabetes risk reduction interventions. Prospective studies are required to examine this hypothesis.

Acute resveratrol supplementation improves flow-mediated dilatation in overweight/obese individuals with mildly elevated blood pressure

BACKGROUND AND AIMS

Flow-mediated dilatation of the brachial artery (FMD) is a biomarker of endothelial function and cardiovascular health. Impaired FMD is associated with several cardiovascular risk factors including hypertension and obesity. Various food ingredients such as polyphenols have been shown to improve FMD. We investigated whether consuming resveratrol, a polyphenol found in red wine, can enhance FMD acutely and whether there is a dose-response relationship for this effect.

METHODS AND RESULTS

19 overweight/obese (BMI 25-35 kg m(-2)) men or post-menopausal women with untreated borderline hypertension (systolic BP: 130-160 mmHg or diastolic BP: 85-100 mmHg) consumed three doses of resveratrol (resVida™ 30, 90 and 270 mg) and a placebo at weekly intervals in a double-blind, randomized crossover comparison. One hour after consumption of the supplement, plasma resveratrol and FMD were measured. Data were analyzed by linear regression versus log(10) dose of resveratrol. 14 men and 5 women (age 55 ± 2 years, BMI 28.7 ± 0.5 kg m(-2), BP 141 ± 2/89 ± 1 mmHg) completed this study. There was a significant dose effect of resveratrol on plasma resveratrol concentration (P < 0.001) and on FMD (P < 0.01), which increased from 4.1 ± 0.8% (placebo) to 7.7 ± 1.5% after 270 mg resveratrol. FMD was also linearly related to log(10) plasma resveratrol concentration (P < 0.01).

CONCLUSION

Acute resveratrol consumption increased plasma resveratrol concentrations and FMD in a dose-related manner. This effect may contribute to the purported cardiovascular health benefits of grapes and red wine.

Exercise for the treatment and management of overweight women with polycystic ovary syndrome: a review of the literature

Polycystic ovary syndrome (PCOS) is characterized by the presence of polycystic ovaries, menstrual dysfunction, infertility and biochemical and clinical hyperandrogenism and is associated with an increased prevalence of cardiometabolic risk factors and psychological problems. Despite the well-established benefits of exercise training and its recommendation as a cornerstone of PCOS management, few well-controlled randomized studies have been conducted evaluating the benefits of exercise training and specific exercise regimes in women with PCOS. From the limited studies there appears to be a beneficial effect of exercise either alone or in combination with energy restriction has shown to improve fitness, cardiovascular, hormonal, reproductive and psychological outcomes. While the addition of regular exercise to energy restriction appears to only have additional benefits for improving body composition, these greater improvements are likely to have long-term implications. While lifestyle modification including regular exercise appears to be an effective strategy for the management of overweight PCOS women, methodological limitations in the studies limit the generalizability of the findings. Future research with rigorous study designs is needed to determine specific exercise guidelines that will provide the greatest benefit for these women.

Obesity: the new childhood disability?

This review addresses the impact of obesity on paediatric physical functioning utilizing the World Health Organization International Classification of Functioning, Disability and Health Framework (ICF). The ICF encompasses functioning (as it relates to all body functions and structures), activities (undertaking a particular task) and participation (in a life situation) with disability referring to impairments in body functions/structures, activity restrictions or participation limitations. Electronic databases were searched for peer-reviewed studies published in English prior to May 2009 that examined aspects of physical functioning in children (≤18 years). Eligible studies (N = 104) were ranked by design and synthesized descriptively. Childhood obesity was found to be associated with deficits in function, including impaired cardiorespiratory fitness and performance of motor tasks; and there was some limited evidence of increased musculoskeletal pain and decrements in muscle strength, gait and balance. Health-related quality of life and the subset of physical functioning was inversely related to weight status. However, studies investigating impacts of obesity on wider activity and participation were lacking. Further research utilizing the ICF is required to identify and better characterize the effects of paediatric obesity on physical function, activity and participation, thereby improving targets for intervention to reduce disability in this population.

Long-term effects of weight loss with a very low carbohydrate and low fat diet on vascular function in overweight and obese patients

OBJECTIVE

To compare the effects of an energy reduced very low carbohydrate, high saturated fat diet (LC) and an isocaloric high carbohydrate, low fat diet (LF) on endothelial function after 12 months.

DESIGN AND SUBJECTS

Forty-nine overweight or obese patients (age 50.0 +/- 1.1 years, BMI 33.7 +/- 0.6 kg m(-2)) were randomized to either an energy restricted ( approximately 6-7 MJ), planned isocaloric LC or LF for 52 weeks. Body weight, endothelium-derived factors, flow-mediated dilatation (FMD), adiponectin, augmentation index (AIx) and pulse wave velocity (PWV) were assessed. All data are mean +/- SEM.

RESULTS

Weight loss was similar in both groups (LC -14.9 +/- 2.1 kg, LF -11.5 +/- 1.5 kg; P = 0.20). There was a significant time x diet effect for FMD (P = 0.045); FMD decreased in LC (5.7 +/- 0.7% to 3.7 +/- 0.5%) but remained unchanged in LF (5.9 +/- 0.5% to 5.5 +/- 0.7%). PWV improved in both groups (LC -1.4 +/- 0.6 m s(-1), LF -1.5 +/- 0.6 m s(-1); P = 0.001 for time) with no diet effect (P = 0.80). AIx and VCAM-1 did not change in either group. Adiponectin, eSelectin, tPA and PAI-1 improved similarly in both groups (P < 0.01 for time).

CONCLUSION

Both LC and LF hypoenergetic diets achieved similar reductions in body weight and were associated with improvements in PWV and a number of endothelium-derived factors. However, the LC diet impaired FMD suggesting chronic consumption of a LC diet may have detrimental effects on endothelial function.

Anti-obesity effects of long-chain omega-3 polyunsaturated fatty acids

Animal studies suggest that increased consumption of the long-chain omega-3 polyunsaturated fatty acids, eicosapentaenoic acid and docosahexaenoic acid, can protect against the development of obesity in animals exposed to an obesogenic diet and reduce body fat when already obese. There is also evidence that increased intakes of these fatty acids can reduce body fat in humans, but human studies are relatively few and have generally been conducted over short time periods with small sample sizes, making it difficult to draw definitive conclusions. Reported reductions in body fat may result from appetite-suppressing effects, adipocyte apoptosis and changes of gene expression in skeletal muscle, heart, liver, intestine and adipose tissues that suppress fat deposition and increase fat oxidation and energy expenditure. We conclude that increased intakes of long-chain omega-3 fatty acids may improve body composition, but longer-term human studies are needed to confirm efficacy and determine whether increasing omega-3 intakes might be an effective strategy to combat obesity.

Comparison of aerobic exercise capacity and muscle strength in overweight women with and without polycystic ovary syndrome

OBJECTIVE

To assess maximal aerobic capacity (VO2max) and muscle strength in overweight and obese women with polycystic ovary syndrome (PCOS) and determine their relationship with metabolic and hormonal factors.

DESIGN

Cross-sectional study.

SETTING

Clinical Research Unit.

POPULATION

Overweight and obese women with PCOS (n = 10) and age-and weight-matched healthy controls (n = 16).

METHODS

VO2max was measured during an incremental treadmill test and maximal isometric (ImS) and isokinetic knee extensor strength (IkS) (120 degrees/second) were assessed by isokinetic dynamometry.

MAIN OUTCOME MEASURES

VO2max, ImS, IkS, waist circumference, blood lipids, glucose, insulin, insulin resistance (homeostatic model assessment [HOMA2]), C-reactive protein (CRP), hormonal profile.

RESULTS

PCOS women had higher levels of testosterone and free testosterone (P < or = 0.05), but there were no significant differences in any cardiovascular disease (CVD) risk markers between the groups. VO2max was similar in women with PCOS and healthy controls (PCOS 26.0 +/- 4.1 ml/kg/minute, controls 25.7 +/- 3.8 ml/kg/minute; P = 0.90), as was ImS (PCOS 1.50 +/- 0.54 Nm/kg, controls 1.50 +/- 0.47 Nm/kg; P = 0.96) and IkS (PCOS 1.04 +/- 0.32 Nm/kg, controls 1.16 +/- 0.23 Nm/kg; P = 0.32). VO2max was inversely related to waist circumference, insulin, HOMA2 and CRP. Waist circumference was inversely associated with ImS and IkS. No significant associations between exercise parameters and hormonal variables were identified.

CONCLUSIONS

Compared to age- and weight-matched healthy overweight and obese women with similar insulin resistance and CVD risk profiles, women with PCOS had similar aerobic capacity and muscle strength. This suggests PCOS, at least in the absence of an adverse metabolic profile is unlikely to limit physical function. Larger studies examining the effects of PCOS on exercise tolerance in a diverse range of PCOS phenotypes is required.

Comparison of aerobic exercise capacity and muscle strength in overweight women with and without polycystic ovary syndrome

OBJECTIVE

To assess maximal aerobic capacity (VO2max) and muscle strength in overweight and obese women with polycystic ovary syndrome (PCOS) and determine their relationship with metabolic and hormonal factors.

DESIGN

Cross-sectional study.

SETTING

Clinical Research Unit.

POPULATION

Overweight and obese women with PCOS (n = 10) and age-and weight-matched healthy controls (n = 16).

METHODS

VO2max was measured during an incremental treadmill test and maximal isometric (ImS) and isokinetic knee extensor strength (IkS) (120 degrees/second) were assessed by isokinetic dynamometry.

MAIN OUTCOME MEASURES

VO2max, ImS, IkS, waist circumference, blood lipids, glucose, insulin, insulin resistance (homeostatic model assessment [HOMA2]), C-reactive protein (CRP), hormonal profile.

RESULTS

PCOS women had higher levels of testosterone and free testosterone (P < or = 0.05), but there were no significant differences in any cardiovascular disease (CVD) risk markers between the groups. VO2max was similar in women with PCOS and healthy controls (PCOS 26.0 +/- 4.1 ml/kg/minute, controls 25.7 +/- 3.8 ml/kg/minute; P = 0.90), as was ImS (PCOS 1.50 +/- 0.54 Nm/kg, controls 1.50 +/- 0.47 Nm/kg; P = 0.96) and IkS (PCOS 1.04 +/- 0.32 Nm/kg, controls 1.16 +/- 0.23 Nm/kg; P = 0.32). VO2max was inversely related to waist circumference, insulin, HOMA2 and CRP. Waist circumference was inversely associated with ImS and IkS. No significant associations between exercise parameters and hormonal variables were identified.

CONCLUSIONS

Compared to age- and weight-matched healthy overweight and obese women with similar insulin resistance and CVD risk profiles, women with PCOS had similar aerobic capacity and muscle strength. This suggests PCOS, at least in the absence of an adverse metabolic profile is unlikely to limit physical function. Larger studies examining the effects of PCOS on exercise tolerance in a diverse range of PCOS phenotypes is required.

The effect of weight loss on anti-Müllerian hormone levels in overweight and obese women with polycystic ovary syndrome and reproductive impairment

BACKGROUND

Anti-Müllerian hormone (AMH) has been proposed as a clinical predictor of improvements in reproductive function following weight loss in overweight and obese women with polycystic ovary syndrome (PCOS). This study aimed to assess whether baseline and/or change in AMH levels with weight loss predict improvements in reproductive function in overweight and obese women with PCOS.

METHODS

Fifty-two overweight and obese women with PCOS and reproductive impairment (age 29.8 +/- 0.8 years, BMI 36.5 +/- 0.7 kg/m(2)) followed a 20-week weight loss programme. AMH, weight, menstrual cyclicity and ovulatory function were assessed at baseline and post-intervention.

RESULTS

Participants who responded with improvements in reproductive function (n = 26) had lower baseline AMH levels (23.5 +/- 3.7 versus 32.5 +/- 2.9 pmol/l; P = 0.03) and experienced greater weight loss (-11.7 +/- 1.2 versus -6.4 +/- 0.9 kg; P = 0.001) compared with those who did not respond (n = 26). Logistic regression analysis showed that weight loss and baseline AMH were independently related to improvements in reproductive function (P = 0.002 and P = 0.013, respectively). AMH levels did not change with weight loss in both responders and non-responders.

CONCLUSIONS

In overweight and obese women with PCOS and reproductive dysfunction, a 20-week weight loss intervention resulted in improvements in reproductive function but no change in AMH levels.

CLINICAL TRIALS REGISTRATION NUMBER

ACTRN12606000198527.

Effect of caloric restriction with and without exercise training on oxidative stress and endothelial function in obese subjects with type 2 diabetes

AIM

Effects of dietary weight loss on endothelial function, particularly when combined with exercise training, is largely unknown in type 2 diabetes. We sought to determine whether aerobic exercise training provided any additional improvements in endothelial function, oxidative stress or other established markers of cardiovascular risk when combined with an energy-restricted diet in patients with type 2 diabetes.

METHODS

In a parallel study design, 29 sedentary, overweight and obese patients with type 2 diabetes (age 52.4 +/- 1.4 years and BMI 34.2 +/- 0.9 kg/m(2)) were randomized to a 12-week moderate energy-restricted diet (~5000 kJ/day and approximately 30% energy deficit) with or without aerobic exercise training [diet only (D), n = 16 and diet plus exercise (DE), n = 13]. Body weight, cardiovascular risk markers, malondialdehyde (MDA, oxidative stress marker), 24-h urinary nitrate/nitrite and flow-mediated dilatation (FMD) of the brachial artery were measured pre- and postintervention.

RESULTS

Both interventions reduced body weight (D 8.9%, DE 8.5%, time effect p < 0.001). Significant reductions in body fat, waist circumference, blood pressure, glycated haemoglobin, glucose, insulin resistance, lipids and MDA and increases in urinary nitrite/nitrate were observed in both groups (time effect p < or = 0.05); however, these changes were not different between treatments. At baseline, FMD was similar in both groups (D 2.5 +/- 0.9%, DE 4.2 +/- 1.2%; p = 0.25) and did not change after the interventions (p = 0.59).

CONCLUSIONS

These results suggest that lifestyle interventions incorporating diet with or without exercise improve glycaemic control, reduce oxidative stress and improve other cardiovascular risk factors but do not improve FMD in obese subjects with type 2 diabetes.

Autologous bone marrow transplantation for children with AML in first remission

In Children's cancer group (CCG) 2891, newly diagnosed patients with AML were randomized between standard and intensive timing induction therapies. Patients in first remission who lacked an HLA matched family donor were randomized between an autologous bone marrow transplantation (ABMT) where marrow was purged with 4 hydroperoxycyclophosphamide and consolidation chemotherapy. One hundred and thirty seven patients received an ABMT. Myeloid and platelet engraftment occurred at a median of 44 and 42 days, respectively. Disease-free survival (DFS), relapse-free survival and overall survival at 8 years post induction were 47% (95% confidence interval (CI): 38-55), 50% (CI: 42-59) and 55% (CI: 46-63), respectively. Multivariate analysis of DFS showed WBC <50 000/microl and having received intensively timed induction therapy were associated with improved DFS. Recipients who received intensive timed induction therapy and whose WBC was less than 50 000/microl had a DFS at 8 years of 62% (CI: 49-73). Conversely, recipients who received intensive timed induction therapy patients whose WBC was > or =50 000/microl had a DFS of 33% (CI: 17-50), P=0.003. The results confirm previous studies that ABMT is effective post remission therapy for pediatric patients with AML in first remission.

Effect of measuring blood lactate concentrations using different automated lactate analysers on blood lactate transition thresholds

This study investigated the effect of using three automated blood lactate analysers (Accusport, Lactate Pro, YSI 1500 Sport) on blood lactate transition thresholds (BLTT). Blood lactate concentrations were measured using the three analysers in rowers (n = 17) and kayakers (n = 6) during incremental exercise. The BLTT determined were: 1) ADAPT lactate threshold (data point preceding lactate increase of > or = 0.4 mmol x l(-1)), 2) log-log lactate threshold (point of lactate increase when log lactate plotted against log of relevant exercise parameter), 3) DMAX anaerobic threshold, 4) ADAPT anaerobic threshold (modified DMAX method), 5) Onset of blood lactate accumulation (OBLA, fixed blood lactate concentration of 4 mmol x l(-1)). Measurements of blood lactate concentration differed between analysers (p < 0.0001), resulting in BLTT differing between analysers when expressed as a blood lactate concentration (p < 0.0001), or when the BLTT was defined as a fixed blood lactate concentration (e.g. OBLA) (p < 0.0001). When expressed as a power output or heart rate using BLTT based on relative changes in lactate concentration (log-log, ADAPT and DMAX thresholds) the values were similar between analysers (p > 0.05), except the Accusport provided higher values for the log-log lactate threshold (p < 0.0001). We concluded that, despite providing significantly different lactate concentrations, unless the Accusport was used to determine the log-log lactate threshold, or values were expressed as a blood lactate concentration, the use of different analysers had little effect on the BLTT.

Oral bovine colostrum supplementation enhances buffer capacity but not rowing performance in elite female rowers

A randomized, double-blind, placebo controlled design was used in which 13 elite female rowers, all of whom had competed at World Championships, were supplemented with 60 g day-1 of either bovine colostrum (BC; n = 6) or concentrated whey protein powder (WP; n = 7) during 9 weeks of pre-competition training. All subjects undertook the study as a group and completed the same training program. Prior to, and after 9 weeks of supplementation and training, subjects completed an incremental rowing test (ROW1) on a rowing ergometer consisting of 3 3 4-min submaximal workloads and a 4-min maximal effort (4 max), each separated by a 1-min recovery period. The rowing test was repeated after a 15-min period of passive recovery (ROW2). The 4 max for ROW1 provided a measure of performance, and the difference between the 4 max efforts of ROW1 and ROW2 provided an index of recovery. Blood lactate concentrations and pH measured prior to exercise and at the end of each workload were used to estimate blood buffer capacity (beta). Food intake was recorded daily for dietary analysis. There were no differences in macronutrient intakes (p >.56) or training volumes (p >.99) between BC and WP during the study period. Rowing performance (distance rowed and work done) during 4 max of ROW2 was less than ROW1 at baseline (p <.05) but not different between groups (p >.05). Performance increased in both rows by Week 9 (p <.001), with no difference between groups (p >.75). However, the increase was greatest in ROW2 (p <.05), such that by Week 9 there was no longer a difference in performance between the two rows in either group (p >.05). b was not different between groups for ROW1 at baseline (BC 38.3 5.0, WP 38.2 7.2 slykes; p >.05) but was higher in BC by Week 9 (BC 40.8 5.9, WP 33.4 5.3 slykes; p <.05). b for ROW2 followed the same pattern of change as for ROW1. We conclude that supplementation with BC improves b, but not performance, in elite female rowers. It was not possible to determine whether b had any effect on recovery.

Bovine colostrum supplementation during endurance running training improves recovery, but not performance

This study examined the effect of supplementation with concentrated bovine colostrum protein powder (intact) on plasma insulin-like growth factor I (IGF-I) concentrations, endurance running performance and recovery. Thirty physically active males completed 8 weeks of running training whilst consuming 60 g x day(-1) of intact powder (n=17) or a concentrated whey protein powder placebo (n=13) in a randomised, double-blind, parallel design. Plasma IGF-I concentrations were measured prior to subjects performing two (approximately 30 min) incremental treadmill running tests to exhaustion (RUN1 and RUN2) separated by 20 min of passive recovery at Weeks 0. 4 and 8. Plasma IGF-I concentrations showed little change in either group (p=0.83). Effective peak running speed (PRSE; i.e. equivalent of peak power) during RUN1 was not different between groups at Week 0 (p>0.99), and had increased by a similar amount in both groups by Week 4 (mean+/-SD, intact 2.2+/-4.0%, placebo 3.2+/-3.3%; 95% confidence interval [95% CI 15.7 to -13.7%; p=0.89) and Week 8 (intact 3.6+/-5.6%, placebo 3.4+/-4.4 %; 95% CI -100.0 to 100.0%; p>0.99). PRSE was less in both groups during RUN2 (p<0.05), but was not significantly different between groups at Week 0 (p>0.99). PRSE during RUN2 tended to have increased more in the placebo group by Week 4 (intact 1.8+/-4.8%, placebo 4.2+/-3.9%; 95% CI 0.2 to -5 0%; p=0.07), but the intact group had increased PRSE significantly more by Week 8 (intact 4.6+/-6.1%, placebo 2.0+/-4.5%; 95% Cl 0.0 to 5.2%; p=0.05). resulting in a significantly faster PRSE (p=0.003). We conclude that supplementation with intact powder did not increase plasma IGF-I concentrations or improve performance during an initial bout of incremental running to exhaustion in our sample. However, performance during a second bout of exercise may be improved by as much as 5.2% in the average subject after 8 weeks of supplementation, possibly due to an enhancement of recovery.

Prognostic variables in newly diagnosed children and adolescents with acute myeloid leukemia: Children's Cancer Group Study 213

The objective of this study was to identify biologic parameters that were associated with either exceptionally good or poor outcome in childhood acute myeloid leukemia (AML). Among the children with AML who entered Children's Cancer Group trial 213, 498 patients without Down syndrome or acute promyelocytic leukemia (APL) comprise the basis for this report. Univariate comparisons of the proportion of patients attaining complete remission after induction (CR) indicate that, at diagnosis, male gender, low platelet count (< or =20 000/microl), hepatomegaly, myelodysplastic syndrome (MDS), French-American- British (FAB) category M5, high (>15%) bone marrow (BM) blasts on day 14 of the first course of induction, and +8 are associated with lower CR rates, while abnormal 16 is associated with a higher CR rate. Multivariate analysis suggests high platelet count at diagnosis (>20 000/microl), absence of hepatomegaly, < or =15% day 14 BM blast percentage, and abnormal 16 are independent prognostic factors associated with better CR. Univariate analysis demonstrated a significant favorable relationship between platelet count at diagnosis (>20 000/microl), absence of hepatomegaly, low percentage of BM blasts (< or =15%), and abnormal 16 with overall survival. Absence of hepatomegaly, < or =15% day 14 BM blast percentage, and abnormal 16 were determined to be independent prognostic factors associated with better survival.

No difference in net uptake or disposal of lactate by trained and untrained forearms during incremental sodium lactate infusion

A number of training adaptations in skeletal muscle might be expected to enhance lactate extraction during hyperlactataemia. The aim of the present study was to determine whether resting endurance-trained forearms exhibit an increased net lactate removal during hyperlactataemia. Six racquet-sport players attended the laboratory for two experiments, separated by 2 weeks. In the first experiment incremental handgrip exercise to fatigue was performed to identify trained (TRFA, n = 6) and untrained (UTFA, n = 5) forearms. In the second experiment net forearm lactate exchange was compared between TRFA and UTFA during an incremental infusion of sodium lactate. TRFA performed more work than UTFA during handgrip exercise [mean (SE) TRFA, 66.1 (9.5) J.100 ml(-1); UTFA, 35.1 (2.3) J.100 ml(-1); P = 0.02] and UTFA exhibited a greater increase in net lactate output relative to work load (P = 0.003). During lactate infusion net lactate uptake across the resting forearms increased linearly with the arterial lactate concentration in both groups (TRFA, r = -0.95 (0.03); UTFA, r= -0.92 (0.04); P < 0.02], with no difference in the regression slopes [TRFA, -1.06 (0.13); UTFA, -1.07 (0.27); P = 0.97] or y-intercepts [TRFA, 0.67 (0.20); UTFA, 1.36 (0.67); P = 0.37] between groups. Almost all of the lactate taken up was disposed of by both groups of forearms [TRFA, 99.6 (0.2)%; UTFA, 98.5 (1.0)%; P = 0.37]. It was concluded that the net uptake and removal of lactate by resting skeletal muscle is a function of the concentration of lactate in the blood perfusing the muscle rather than the muscle training status.

Glutathione S-transferase polymorphisms and outcome of chemotherapy in childhood acute myeloid leukemia

PURPOSE

Glutathione S-transferase theta (GSTT1) and mu (GSTM1) genes are polymorphic, the genes being absent in approximately 15% and 50% of the population, respectively. Because glutathione S-transferases may be involved in the metabolism of chemotherapy drugs, we hypothesized that presence or absence of the genes may influence the outcome of treatment for childhood acute myeloid leukemia (AML).

PATIENTS AND METHODS

We genotyped GSTT1 and GSTM1 in 306 children with AML receiving chemotherapy on Children's Cancer Group therapeutic studies. Outcomes were compared in those with and without GSTT1 and GSTM1 genes.

RESULTS

Patients with the GSTT1-negative genotype had reduced survival compared with those with at least one GSTT1 allele (GSTT1 positive) (52% v 40% at 5 years; log-rank P =.05). A multivariate model of survival adjusted for age group, sex, WBC count, chloroma, CNS involvement, and French-American-British group confirmed the increased risk of death in the GSTT1-null cases (relative risk, AQ 1.6; P =.02). The frequency of death in remission was increased in GSTT1-negative cases compared with GSTT1-positive cases (24% v 12%, log-rank P =.05). The frequency of relapse from end of induction was similar in GSTT1-negative and GSTT1-positive cases (38% v 35%, log-rank P =.5).

CONCLUSION

Children who lacked GSTT1 had greater toxicity and reduced survival after chemotherapy for AML compared with children with at least one GSTT1 allele. If confirmed in further studies, GSTT1 genotype might be useful in selecting appropriate chemotherapy regimens for children with AML.

A comparison of allogeneic bone marrow transplantation, autologous bone marrow transplantation, and aggressive chemotherapy in children with acute myeloid leukemia in remission

Intensive, myelosuppressive therapy is necessary to maximize outcomes for patients with acute myeloid leukemia (AML). A comparison was made of 3 aggressive postremission approaches for children and adolescents with AML in a randomized trial, CCG-2891. A total of 652 children and adolescents with AML who achieved remission on 2 induction regimens using identical drugs and doses (standard and intensive timing) were eligible for allocation to allogeneic bone marrow transplantation (BMT) based on matched related donor status (n = 181) or randomization to autologous BMT (n = 177) or to aggressive high-dose cytarabine-based chemotherapy (n = 179). Only 115 patients (18%) refused to participate in the postremission phase of this study. Overall compliance with the 3 allocated regimens was 90%. At 8 years actuarial, 54% +/- 4% (95% confidence interval) of all remission patients remain alive. Survival by assigned regimen ("intent to treat") is as follows: allogeneic BMT, 60% +/- 9%; autologous BMT, 48% +/- 8%; and chemotherapy, 53% +/- 8%. Survival in the allogeneic BMT group is significantly superior to autologous BMT (P =.002) and chemotherapy (P =.05); differences between chemotherapy and autologous BMT are not significant (P =.21). No potential confounding factors affected results. Patients receiving intensive-timing induction therapy had superior long-term survival irrespective of postremission regimen received (allogeneic BMT, 70% +/- 9%; autologous BMT, 54% +/- 9%; chemotherapy, 57% +/- 10%). Allogeneic BMT remains the treatment of choice for children and adolescents with AML in remission, when a matched related donor is available. For all others, there is no advantage to autologous BMT; hence, aggressive nonablative chemotherapy should be used.

Prevalence and prognostic significance of Flt3 internal tandem duplication in pediatric acute myeloid leukemia

The Flt3 gene encodes a tyrosine kinase receptor that regulates proliferation and differentiation of hematopoietic stem cells. An internal tandem duplication of the Flt3 gene (Flt3/ITD) has been reported in acute myelogenous leukemia (AML) and may be associated with poor prognosis. We analyzed diagnostic bone marrow specimens from 91 pediatric patients with AML treated on Children's Cancer Group (CCG)-2891 for the presence of the Flt3/ITD and correlated its presence with clinical outcome. Fifteen of 91 samples (16.5%) were positive for the Flt3/ITD. Flt3/ITD-positive patients had a median diagnostic white count of 73 800 compared with 28 400 for the Flt3/ITD-negative patients (P =.05). The size of the duplication ranged from 21 to 174 base pairs (bp). Nucleotide sequencing of the abnormal polymerase chain reaction products demonstrated that all duplications involved exon 11 of the Flt3 gene and also preserved the reading frame. Lineage restriction analysis revealed that Flt3/ITD was not present in the lymphocytes, suggesting a lack of stem cell involvement for this mutation. None of the Flt3/ITD-positive patients had unfavorable cytogenetic markers, and there was no predominance of a particular FAB class. The remission induction rate was 40% in Flt3/ITD-positive patients compared with 74% in Flt3/ITD-negative ones (P =.005). The Kaplan-Meier estimates of event-free survival at 8 years for patients with and without Flt3/ITD were 7% and 44%, respectively (P =.002). Multivariate analysis demonstrated that presence of the Flt3/ITD was the single most significant, independent prognostic factor for poor outcome (P =.009) in pediatric AML.

Pesticide exposures in children with non-Hodgkin lymphoma

BACKGROUND

The association between pesticide exposure and non-Hodgkin lymphoma (NHL) in adults has been the subject of numerous case-control and cohort studies. However, to the authors' knowledge, data regarding pesticide exposures in children diagnosed with NHL have been lacking.

METHODS

The Children's Cancer Group conducted a study comparing 268 children who developed NHL or leukemia with bulk disease with a group of matched, randomly selected regional population controls. The telephone interviews of both the case and control mothers included selected questions regarding occupational and home exposures to pesticides around the time of the index pregnancy and exposure of the child.

RESULTS

A significant association was found between risk of NHL and increased frequency of reported pesticide use in the home (odds ratio [OR] = 7.3 for use most days; trend P = 0.05), professional exterminations within the home (OR = 3.0; P = 0.002), and postnatal exposure (OR = 2.4; P = 0.001). Elevated risks were found for T-cell and B-cell lymphomas; for lymphoblastic, large cell, and Burkitt morphologies; and in both young (age < 6 years) and older children. There was an increased risk of NHL with occupational exposure to pesticides (OR = 1.7) that was not significant overall, but that was significant for Burkitt lymphoma (OR = 9.6; P < 0.05).

CONCLUSIONS

The results of the current study provide further evidence linking pesticide exposure to the risk of NHL, but the authors were unable to implicate any specific agent.

Therapy for acute myeloid leukemia: intensive timing of induction chemotherapy

Children's Cancer Group (CCG) study 2891 for children with previously untreated acute myeloid leukemia enrolled more than 1200 patients between 1989 and 1995. This study showed that increased dose intensity during induction therapy improved survival for all patients except those with Down syndrome, where it proved harmful. Although increased dose intensity improved survival, it did not improve remission induction rate, indicating that the quality of remissions varies. This finding complicates the evaluation of postremission therapy options, which CCG 2891 also evaluated. Survival with related-donor allogeneic bone marrow transplantation was superior to survival with both purged autologous bone marrow transplantation and a more standard chemotherapy consolidation, whereas survival for autologous transplantation and chemotherapy was equivalent.

Glutathione S-transferase polymorphisms in children with myeloid leukemia: a Children's Cancer Group study

GSTM1 and GSTT1 are polymorphic genes. Absence of enzyme activity is due to homozygous inherited deletion of the gene, reducing detoxification of carcinogens such as epoxides and alkylating agents and potentially increasing cancer risk. We hypothesized that GST null genotype would increase risk of acute myeloid leukemia and myelodysplasia (AML/MDS) in children. DNA was extracted from bone marrow slides of 292 AML/MDS patients. PCR amplification was used to assign GSTM1 and GSTT1 genotypes for cases and controls. Given that the frequency of the null genotype varies by ethnicity and that the majority of the cases were Caucasian, analyses were restricted to 232 white (non-Hispanic) cases and 153 Caucasian non cancer controls. The frequency of GSTM1 null was significantly increased in AML/MDS cases compared with controls [64 versus 47%; odds ratio (OR), 2.0 [95% confidence interval (CI), 1.3-3.1]; P = 0.001], whereas the frequency of GSTT1 null genotype in AML/MDS cases was not statistically different from controls. AML comprises biologically distinct subtypes, and a test for homogeneity revealed a statistically significant difference among subtypes (P = 0.04; df, 8) for GSTM1 only. In particular, there was an increased frequency of GSTM1 null genotypes in French-American-British groups M3 [82%; n = 22; OR, 5.1 (95% CI, 1.6-21.3)] and M4 [72%; n = 53; OR, 2.9 (95% CI, 1.4-6.0)]. We conclude that the GSTM1 null genotype is a significant risk factor for childhood AML, particularly French-American-British groups M3 and M4. This may indicate an important role for exogenous carcinogens in the etiology of childhood AML.

Alpha hemolytic streptococcal infection during intensive treatment for acute myeloid leukemia: a report from the Children's cancer group study CCG-2891

PURPOSE

Past reports indicate that alpha hemolytic streptococcal (AHS) organisms are a common cause of infection among acute myeloid leukemia (AML) patients. This study was intended to ascertain the population incidence and rate (infections per 100 patient-days of treatment) of AHS and to identify associated risk factors.

PATIENTS AND METHODS

Patients (n = 874 with 151,350 days of risk) enrolled on the Children's Cancer Group (CCG) protocol for newly diagnosed AML, CCG-2891, which randomly assigned intensity of induction and intensification, were prospectively evaluated for infectious complications.

RESULTS

AHS occurred in 21% of patients, was primarily blood borne (86%), made up 21% of bacteremic infections, and had a recurrent incidence of 31% during subsequent therapy. AHS was more often life-threatening (59%) than other infections (41%) (P = .001). AHS rates increased with age less than 10 years (odds ratio [OR], 2.0; P = .007), intensively timed induction (OR, 1.8 to 1.9; P = .02), and high-dose cytarabine intensification (OR, 3.7; P<.0001). Among all courses, the greatest incidence (19%) and rate (0.41) were associated with the use of high-dose cytarabine. Gastrointestinal toxicity correlated significantly with AHS bacteremia (P<.01). Infection with AHS resulted in increased hospital days (P =.0001). Only among bone marrow transplant patients were overall survival (OR, 2.8; P = .0001) and disease-free survival (OR, 2.1; P = .008) decreased after AHS bacteremia.

CONCLUSION

This study, the first to prospectively examine AHS incidence among uniformly treated patients in multiple institutions, established that as the intensity of AML therapy has increased, so has the rate of AHS. Young children, those with previous AHS bacteremias, and those receiving high-dose cytarabine are at particularly high risk of AHS bacteremia.

Paternal military service and risk for childhood leukemia in offspring

To assess the association between paternal military service and risk for childhood leukemia, the authors analyzed data from three case-control studies conducted by the Children's Cancer Group from 1983 to 1993. A total of 605 acute myeloid leukemia (AML, age < or = 18 years) cases, 2,117 acute lymphoblastic leukemia (ALL, age < or = 14 years) cases, and 3,155 individually matched controls were included in these studies. Paternal military history and other exposure data were obtained in 2,343 matched case-control sets, including 1,805 ALL and 528 AML cases. Paternal general military service was not associated with the leukemia risk. A small, but significant, increase in the risk for AML was seen, however, among offspring of veterans who had served in Vietnam or Cambodia (odds ratio (OR) = 1.7; 95% confidence interval (CI): 1.0, 2.9), after adjustment for paternal education, race, income, smoking, X-ray exposure, and marijuana use. The risk was predominantly present in children diagnosed before the age of 2 (OR = 4.6; 95% CI: 1.3, 16.1), although there were inconsistencies in the risks associated with length of time served and interval between service and diagnosis of leukemia. Military service in Vietnam or Cambodia was unrelated to the risk for ALL. The etiologic importance, if any, of these observations has yet to be determined.

Indoor residential radon exposure and risk of childhood acute myeloid leukaemia

Exposure to radon has been identified as a risk factor for lung cancer in uranium miners, but evidence of adverse health effects due to indoor radon exposure is inconsistent. Ecological studies have suggested a correlation between indoor radon levels and leukaemia incidence. We evaluated the risk associated with indoor residential radon exposure within a larger interview-based case-control study of risk factors for childhood acute myeloid leukaemia (AML). A total of 173 cases and 254 controls met the eligibility criteria, and information was collected through telephone interviews with parents and analysis of alpha-track radon detectors placed in the home for a period of 1 year. No association was observed between radon exposure and risk of AML, with adjusted odds ratios of 1.2 (95% confidence interval (CI) 0.7-1.8) for 37-100 Bq m(-3) and 1.1 (95% CI 0.6-2.0) for > 100 Bq m(-3) compared with < 37 Bq m(-3). Although there was an inverse association between radon level and AML risk among children < 2 years at diagnosis, among children > or = 2 years, AML risk was increased among those with higher radon exposure. The observed association after age 2 is most likely due to chance. Overall, there was no association between residential radon and risk of childhood AML.

Breast-feeding and risk of childhood acute leukemia

BACKGROUND

Breast-feeding is well known to have a protective effect against infection in infants. Although the long-term effects of breast-feeding on childhood cancer have not been studied extensively, a protective effect against childhood Hodgkin's disease and lymphoma has been suggested previously from small investigations. In this study, we tested the hypothesis that breast-feeding decreases the risk of childhood acute leukemia.

METHODS

A total of 1744 children with acute lymphoblastic leukemia (ALL) and 1879 matched control subjects, aged 1-14 years, and 456 children with acute myeloid leukemia (AML) and 539 matched control subjects, aged 1-17 years, were included in the analysis. Information regarding breast-feeding was obtained through telephone interviews with mothers. All leukemias combined, histologic type of leukemia (ALL versus AML), immunophenotype of ALL (early pre-B cell, pre-B cell, or T cell), and morphology of AML were assessed separately in the data analysis.

RESULTS

Ever having breast-fed was found to be associated with a 21% reduction in risk of childhood acute leukemias (odds ratio [OR] for all types combined = 0.79; 95% confidence interval [CI] = 0.70-0.91). A reduction in risk was seen separately for AML (OR = 0.77; 95% CI = 0.57-1.03) and ALL (OR = 0.80; 95% CI = 0.69-0.93). The inverse associations were stronger with longer duration of breast-feeding for total ALL and AML; for M0, M1, and M2 morphologic subtypes of AML; and for early pre-B-cell ALL.

CONCLUSION

In this study, breast-feeding was associated with a reduced risk of childhood acute leukemia. If confirmed in additional epidemiologic studies, our findings suggest that future epidemiologic and experimental efforts should be directed at investigating the anti-infective and/or immune-stimulatory or immune-modulating effects of breast-feeding on leukemogenesis in children.

Parental occupational exposure to hydrocarbons and risk of acute lymphocytic leukemia in offspring

Parental exposure to hydrocarbons at work has been suggested to increase the risk of childhood leukemia. Evidence, however, is not entirely consistent. Very few studies have evaluated the potential parental occupational hazards by exposure time windows. The Children's Cancer Group recently completed a large-scale case-control study involving 1842 acute lymphocytic leukemia (ALL) cases and 1986 matched controls. The study examined the association of self-reported occupational exposure to various hydrocarbons among parents with risk of childhood ALL by exposure time window, immunophenotype of ALL, and age at diagnosis. We found that maternal exposure to solvents [odds ratio (OR), 1.8; 95% confidence interval (CI), 1.3-2.5] and paints or thinners (OR, 1.6; 95% CI, 1.2-2.2) during the preconception period (OR, 1.6; 95% CI, 1.1-2.3) and during pregnancy (OR, 1.7; 95% CI, 1.2-2.3) and to plastic materials during the postnatal period (OR, 2.2; 95% CI, 1.0-4.7) were related to an increased risk of childhood ALL. A positive association between ALL and paternal exposure to plastic materials during the preconception period was also found (OR, 1.4; 95% CI, 1.0-1.9). The ALL risk associated with parental exposures to hydrocarbons did not vary greatly with immunophenotype of ALL. These results suggest that the effect of parental occupational exposure to hydrocarbons on offspring may depend on the type of hydrocarbon and the timing of the exposure.

Congenital abnormalities in children with acute leukemia: a report from the Children's Cancer Group

OBJECTIVE

To evaluate the risk of leukemia associated with congenital abnormalities, a series of matched case-control studies were carried out by the Children's Cancer Group.

STUDY DESIGN

Eligible case patients for this analysis included individuals with a diagnosis of leukemia confirmed at a Children's Cancer Group member institution: 2117 diagnosed with acute lymphoblastic leukemia (ALL) and 605 diagnosed with acute myelogenous leukemia (AML). Case patients were compared with matched regional population control subjects selected by using a modified random digit dialing method. Data regarding congenital abnormalities in index children and their siblings were collected by telephone interview with the biologic mother. Relative risk was estimated by using the odds ratio (OR).

RESULTS

More congenital abnormalities were reported in index case patients with ALL than in control subjects, with statistically significant increases in multiple birthmarks (OR = 1.35), Down syndrome (OR = 4.85), congenital heart defects (OR = 1.48), and pancreas-digestive tract abnormalities (OR = 2.52). Similarly, birth defects were reported more often among index case patients with AML than control subjects (OR = 2.90), with significant increases in multiple birthmarks (OR = 1.89), Down syndrome (OR = 76.80), mental retardation (OR = 14.47), and congenital heart defects (OR = 2.07). Exclusion of case patients with Down syndrome from the analysis did not change the statistically significant excess of pancreas-digestive tract abnormalities in case patients with ALL or the excess of multiple birthmarks observed in both case patients with ALL and those with AML. For both the ALL and AML analyses, no significant differences in the number of reported congenital abnormalities were seen between siblings of case patients and siblings of control subjects.

CONCLUSION

Many of the observed associations with congenital abnormalities occurred in the children with Down syndrome, who are known to have an increased risk for leukemia. The higher reported frequency of birthmarks among case patients may suggest a genetic component to leukemia risk.

Epidemiology of osteosarcoma and Ewing's sarcoma in childhood: a study of 305 cases by the Children's Cancer Group

BACKGROUND

The Children's Cancer Group conducted a case-control study to determine the role of a broad range of environmental and familial factors in the etiology of Ewing's sarcoma and osteosarcoma in children. These factors included radiation exposure and, for children with osteosarcoma, parental exposure to beryllium.

METHODS

The parents of 152 children with osteosarcoma and 153 children with Ewing's sarcoma were interviewed by telephone. Controls were obtained by random digit dialing and were matched to cases by age and race.

RESULTS

Female osteosarcoma patients had earlier onset of breast development (age 11.4 vs. 11.8 years, P=0.03) and menarche (age 12.1 vs. 12.5 years, P=0.002) but no significant differences in growth, whereas male osteosarcoma patients were similar in age at the onset of secondary sexual characteristics but reported significantly less weight gain during their growth spurt (6.6 vs. 11.7 kg, P=0.003). For children with Ewing's sarcoma, the growth spurt began earlier (age 12.1 vs. 12.7 years, P=0.12) and resulted in less weight and height gain (5.2 vs. 9.7 kg, P=0.002, and 10.2 vs. 12.7 cm, P=0.02, respectively) for males, but no differences were observed among females. For factors not related to growth and development (including a wide range of occupational, medical, and household exposures), there was little evidence of an etiologic role with respect to either tumor type.

CONCLUSIONS

Differences between cases and controls with respect to growth and development showed no consistent pattern. This study did not identify any important risk factors for either type of childhood bone tumor.

Lack of TEL/AML1 fusion in pediatric AML: further evidence for lineage specificity of TEL/AML1

BACKGROUND

The TEL/AML1 fusion associated with t(12;21)(p13;q22) is the most common gene rearrangement in childhood malignancy, occurring in approximately 25% of pediatric acute lymphoblastic leukemia. The TEL/AML1 rearrangement is cryptic at the cytogenetic level but confers a favorable prognosis. The AML1 gene was first identified by virtue of its involvement in adult and pediatric acute myeloid malignancies associated with t(8;21) and t(3;21)(q26;q22.1). We have therefore determined the frequency of the TEL/AML1 fusion in pediatric myeloid leukemias by RT-PCR analysis.

METHODS

Total RNA was isolated from cryopreserved bone marrow samples of 38 pediatric patients with AML. RNA quality was controlled for by amplification of the TEL gene. An RT-PCR assay was then used to test for the presence of the TEL/AML1 fusion.

RESULTS

29 patients had adequate RNA for analysis. Zero out of 29 pediatric AML patients had evidence for the TEL/AML1 fusion by RT-PCR.

CONCLUSIONS

The TEL/AML1 fusion does not occur in children with AML and suggests that the TEL/AML1 rearrangement is restricted in pediatric hematologic malignancy to B lineage ALL.

Distinctive demography, biology, and outcome of acute myeloid leukemia and myelodysplastic syndrome in children with Down syndrome: Children's Cancer Group Studies 2861 and 2891

In recent pediatric trials of acute myeloid leukemia (AML), children with Down syndrome (DS) have had significantly more megakaryoblastic leukemia and have experienced better outcome than other children. To further characterize AML in DS, Children's Cancer Group Studies 2861 and 2891 prospectively studied demography, biology, and response in AML and myelodysplastic syndrome (MDS) of children with and without DS. These studies evaluated timing of induction therapy and compared postremission chemotherapy with marrow transplantation in 1,206 children. One-hundred eighteen (9.8%) had DS, a fourfold increase in 20 years. DS patients were younger, had lower white blood cell and platelet counts, more antecedent MDS, acute megakaryoblastic leukemia or undifferentiated AML, and an under-representation of chromosomal translocations (P < .001 for each variable). Four-year event-free survival in DS was 69% versus 35% in others (P < .001). Intensively timed induction conferred significantly higher mortality in DS patients; bone marrow transplantation offered no advantage. Conventional induction followed by chemotherapy achieved an 88%, 4-year, disease-free survival in DS patients versus 42% in others (P < .001). Megakaryoblastic leukemia was unfavorable in others but prognostically neutral in DS. AML in DS is demographically and biologically distinct from AML in other children. It is singularly responsive to conventional chemotherapy and may warrant even less therapy. The increasing proportion of DS patients with AML most likely reflects changes in attitudes about entering DS patients on AML trials and possibly increasing ability to distinguish megakaryoblastic leukemia from lymphoid leukemia.

High birth weight and risk of specific childhood cancers: a report from the Children's Cancer Group

OBJECTIVES

High birth weight has been associated with a number of childhood cancers. This study was conducted to test the hypothesis that elevated birth weight is associated with an increased risk of diagnosis-specific and age-specific groups of childhood cancers.

METHODS

A case-control study, using a large Children's Cancer Group database, examined birth weight as a risk factor for childhood cancer. Birth weight information for the index child was available for 3711 cases and 816 control subjects.

RESULTS

There was a statistically significant increased risk of acute lymphoblastic leukemia, Wilms' tumor, and neuroblastoma with increasing birth weight (p, trend = 0.006, 0.003, and 0.001, respectively). A statistically significant decreased risk of cancer was observed for soft tissue sarcoma (p, trend = 0.04). When data were stratified on the basis of age at diagnosis, many of these associations were apparent for children whose disease was diagnosed before the age of 2 years. Moreover, for acute myeloid leukemia, age at diagnosis was an important effect modifier. For children with acute myeloid leukemia whose disease was diagnosed before 2 years of age, there was a statistically significant increased risk with high birth weight (odds ratio = 2.5, 95% confidence interval 1.1 to 5.5); there was no increased risk of acute myeloid leukemia with high birth weight noted for children whose disease was diagnosed after 2 years of age (odds ratio 1.3, 95% confidence interval 0.8 to 2.2).

CONCLUSIONS

Biologic studies are needed to address why high birth weight may increase risk (particularly at younger ages) of development of certain cancers.

Epidemiologic study of Langerhans cell histiocytosis in children

OBJECTIVE

The etiology and pathogenesis of Langerhans cell histiocytosis (LCH) remain poorly understood. We conducted an exploratory epidemiologic study to investigate potential risk factors associated with LCH.

STUDY DESIGN

We used a case-control study design to obtain data from parents of children with LCH (n = 459) who were members of the Histiocytosis Association of America and Canada. The two control groups consisted of 683 community control subjects and 3719 children with childhood cancers treated at participating Children's Cancer Group institutions.

RESULTS

The median age at diagnosis of LCH was 1.8 years (range 0.1 to 14.6 years). Cases were categorized as multisystem LCH (MS-LCH) (n = 208) and single-system LCH (SS-LCH) (n = 198). Statistically significant associations included the following: infections in the neonatal period (MS-LCH, odds ratio (OR) = 2.2), solvent exposure (SS-LCH, OR = 54.9), childhood vaccinations (MS-LCH and SS-LCH, OR = 0.4), thyroid disease in the proband (MS-LCH and SS-LCH, OR = 21.6), and family history of thyroid disease (MS-LCH and SS-LCH, OR = 1.4). The association with thyroid disease in the proband was explained partially by the involvement of the pituitary, with the relative risk decreasing when patients with diabetes insipidus and thyroid involvement were excluded from analysis.

CONCLUSIONS

This large hypothesis-generating study provides directions for future investigations in well-designed population-based or hospital-based epidemiologic studies.

Timing and magnitude of decline in alpha-fetoprotein levels in treated children with unresectable or metastatic hepatoblastoma are predictors of outcome: a report from the Children's Cancer Group

PURPOSE

We analyzed data on 31 children with primary unresectable or metastatic hepatoblastoma (HB) to investigate possible prognostic correlations between the serum level of alpha-fetoprotein (AFP), its changes during treatment, and outcome.

PATIENTS AND METHODS

Patients were treated according to the Children's Cancer Group (CCG) protocol 823F, which included an initial surgery before eight courses of chemotherapy that consisted of cisplatin immediately followed by a continuous infusion of doxorubicin. Four courses were given before and four after the second surgery. AFP levels were measured before treatment, before and after second surgery, and at the end of treatment.

RESULTS

Twenty-four of 31 patients showed a decline of > or = 1 log in AFP levels before second surgery (early responders). By the end of treatment, there were 16 patients, all early responders, without clinical or radiographic evidence of tumor and with normal AFP levels. Fifteen of those 16 had a decline of > or = 2 logs in AFP before second surgery (large early response). Of the 15 patients who failed to respond to treatment, 10 died, among whom only one patient had a large early response. A large early response was the strongest independent predictor of outcome in a univariate and multivariate Cox regression model, and patients with such a response had the best survival (P < .0001).

CONCLUSION

For children with unresectable or metastatic HB, early changes in AFP levels are a reliable predictor of outcome and can be used for identification of poor responders to treatment, ie, patients whose AFP level fails to decrease 2 logs before second surgery should be considered for alternative treatment.

Reduced performance of male and female athletes at 580 m altitude

This study examined the effect of mild hypobaria (MH) on the peak oxygen consumption (VO2peak) and performance of ten trained male athletes [x (SEM); VO2peak = 72.4 (2.2) ml x kg(-1) x min(-1)] and ten trained female athletes [VO2peak = 60.8 (2.1) ml x kg(-1) x min(-1)]. Subjects performed 5-min maximal work tests on a cycle ergometer within a hypobaric chamber at both normobaria (N, 99.33 kPa) and at MH (92.66 kPa), using a counter-balanced design. MH was equivalent to 580 m altitude. VO2peak at MH decreased significantly compared with N in both men [-5.9 (0.9)%] and women [-3.7 (1.0)%]. Performance (total kJ) at MH was also reduced significantly in men [-3.6 (0.8)%] and women [-3.8 (1.2)%]. Arterial oxyhaemoglobin saturation (SaO2) at VO2peak was significantly lower at MH compared with N in both men [90.1 (0.6)% versus 92.0 (0.6)%] and women [89.7 (3.1)% versus 92.1 (3.0)%]. While SaO2 at VO2peak was not different between men and women, it was concluded that relative, rather than absolute. VO2peak may be a more appropriate predictor of exercise-induced hypoxaemia. For men and women, it was calculated that 67-76% of the decrease in VO2peak could be accounted for by a decrease in O2 delivery, which indicates that reduced O2 tension at mild altitude (580 m) leads to impairment of exercise performance in a maximal work bout lasting approximately 5 min.

Prediction of relapse of pediatric acute myeloid leukemia by use of multidimensional flow cytometry

BACKGROUND

Most patients receiving therapy for acute myeloid leukemia (AML) enter an interval in which leukemic blast cells cannot be detected by light microscopy (i.e., morphologic remission). However, many of these patients experience a subsequent relapse. Multidimensional flow cytometry, which allows the discrimination of antigens expressed on normal and malignant cells, can detect small numbers of cancer cells in bone marrow or peripheral blood specimens. This technique enables the detection of one leukemic blast cell among 10(3) to 10(2) normal regenerating hematopoietic cells.

PURPOSE

We determined whether the presence of residual leukemic blast cells, identified in the bone marrow of pediatric patients with AML by use of multidimensional flow cytometry, would be predictive of subsequent leukemic relapse.

METHODS

Multidimensional flow cytometry was performed on 205 marrow specimens collected throughout the course of treatment from 39 patients who had achieved morphologic remission. The analyses employed monoclonal antibodies directed against CD45 in combination with mixed pairs of monoclonal antibodies directed against 10 other antigens. A time-varying Cox regression analysis that controlled for sample time intervals, age, sex, morphologic classification of disease, and white blood cell count at diagnosis was used to relate the multidimensional flow cytometric results to the risk of relapse after achieving remission. Reported P values are two-sided.

RESULTS

Thirty-five of the 39 patients had bone marrow specimens available from the time that first morphologic remission was achieved. Leukemic blast cells were detected in the specimens from 19 (54%) of these 35 patients. Twenty-five of the 35 patients did not receive an allogeneic (i.e., from a different genetic background) bone marrow transplant during first morphologic remission, and 13 of 14 with residual leukemic cells experienced a relapse at a median time of 153 days after diagnosis (range, 48-863 days). Nine of the 11 patients who did not receive an allogeneic bone marrow transplant and lacked evidence of leukemic blast cells at first morphologic remission relapsed at a median time of 413 days after diagnosis (range, 321-794 days). Among the 10 individuals who received an allogeneic bone marrow transplant during first morphologic remission, five were positive for leukemic blast cells and five were negative; one of these patients (positive for leukemic blast cells) experienced a relapse 265 days after diagnosis, and three others died of transplant-related complications. The estimated risk of relapse during intervals of multidimensional flow cytometric positivity (i.e., intervals of remission for which the immediately preceding cytometry measurement was positive) was 2.8 times greater than that during negative intervals (95% confidence interval = 1.1-7.0; P = .02).

CONCLUSIONS AND IMPLICATIONS

Multidimensional flow cytometry identifies residual leukemia in more than half of the patients with AML who are in morphologic remission. The detection of leukemic blast cells in these patients by multidimensional flow cytometry is predictive of a more rapid relapse.