Assessing domain match and feasibility of candidate instruments matching with OMERACT endorsed domains to measure flare in knee and hip osteoarthritis

PURPOSE

To evaluate the domain match (truth) and feasibility of candidate instruments assessing flare in knee and hip osteoarthritis (OA) according to the identified domains.

MATERIAL AND METHODS

From a literature review (575 papers), instruments were selected and evaluated using the truth and feasibility elements of the OMERACT Filter 2.2. These were evaluated by 26 experts, including patients, in two Delphi survey rounds. The final selection was obtained by a vote.

RESULTS

44 instruments were identified. In Delphi Round 1, five instruments were selected. In Round 2, all instruments obtained at least 75 % in terms of content match with the endorsed domains and feasibility. In the final selection, the Flare-OA questionnaire obtained 100 % favorable votes.

CONCLUSION

Through consensus of the working group, the Flare-OA questionnaire was selected as the best candidate instrument to move into a full assessment of its measurement properties using the OMERACT Filter 2.2.

'Do we know if we need to reduce head impact exposure?': A mixed-methods study highlighting the varied understanding of the long-term risk and consequence of head impact exposure across all stakeholders at the highest level of rugby union

Background

One strategy to prevent and manage concussion is to reduce head impacts, both those resulting in concussion and those that do not. Because objective data on the frequency and intensity of head impacts in rugby union (rugby) are sparse, stakeholders resort to individual perceptions to guide contact training. It is unknown whether there is a level of contact training that is protective in preparing elite players for contact during matches.

Objectives

This study aimed to describe how contact training is managed in elite male rugby, and how staff and players perceive contact training load and head impact load.

Methods

This was a sequential explanatory mixed-methods study. Forty-four directors of rugby, defence coaches, medical and strength/conditioning staff and 23 players across all 13 English Premiership Rugby Union clubs and the National senior team participated in semi-structured focus groups and completed two bespoke questionnaires.

Results

The study identified the varied understanding of what constitutes head impact exposure across all stakeholder groups, resulting in different interpretations and a range of management strategies. The findings suggest that elite clubs conduct low levels of contact training; however, participants believe that some exposure is required to prepare players and that efforts to reduce head impact exposure must allow for individualised contact training prescription.

Conclusion

There is a need for objective data, possibly from instrumented mouthguards to identify activities with a high risk for head impact and possible unintended consequences of reduced exposure to these activities. As data on head impact exposure develop, this must be accompanied with knowledge exchange within the rugby community.

Development and validation of the Flare-OA questionnaire for measuring flare in knee and hip osteoarthritis

OBJECTIVE

Ability to assess flares in osteoarthritis (OA) of the knee and hip (KHOA) is important in clinical care and research. Using mixed methods, we developed a self-reported instrument measuring flare and assessed its psychometric properties.

METHODS

We constructed questionnaire items from semi-structured interviews and a focus group (patients, clinicians) by using a dual-language (English-French) approach. A Delphi consensus method was used to select the most relevant items. Patients with OA from Australia, France and the United States completed the preliminary Flare-OA, HOOS, KOOS and Mini-OAKHQOL questionnaires online. We used a factor analysis and content approach to reduce items and determine structural validity. We tested the resulting questionnaire (score 0-100) for internal consistency, convergent and known-groups validity.

RESULTS

Initially, 180 statements were generated and reduced to 33 items in five domains (response 0 = not at all, to 10 = absolutely) by Delphi consensus (50 patients, 116 professionals) and an expert meeting. After 398 patients (mean [SD] age 64 [8.5] years, 70.4% female, 86.7% knee OA) completed the questionnaire, it was reduced to 19 items by factor analysis and a content approach (RMSEA = 0.06; CFI = 0.96; TLI = 0.94). The Cronbach's alpha was >0.9 for the five domains and the whole questionnaire. Correlation coefficients between Flare-OA and other instrument scores were as predicted, supporting construct validity. The difference in Flare-OA score between patients with and without flare (31.8) largely exceeded 2 SEM (10.2).

CONCLUSION

Flare-OA is a valid and reliable patient-reported instrument for assessing the occurrence and severity of flare in patients with KHOA in clinical research.

IL-1 Signal Inhibition In Alcoholic Hepatitis (ISAIAH): a study protocol for a multicentre, randomised, placebo-controlled trial to explore the potential benefits of canakinumab in the treatment of alcoholic hepatitis

BACKGROUND

Alcohol consumption causes a spectrum of liver abnormalities and leads to over 3 million deaths per year. Alcoholic hepatitis (AH) is a florid presentation of alcoholic liver disease characterized by liver failure in the context of recent and heavy alcohol consumption. The aim of this study is to explore the potential benefits of the IL-1β antibody, canakinumab, in the treatment of AH.

METHODS

This is a multicentre, double-blind, randomised placebo-controlled trial. Participants will be diagnosed with AH using clinical criteria. Liver biopsy will then confirm that all histological features of AH are present. Up to 58 participants will be recruited into two groups from 15 centres in the UK. Patients will receive an infusion of Canakinumab or matched placebo by random 1:1 allocation. The primary outcome is the difference between groups in the proportion of patients demonstrating histological improvement and will compare histological appearances at baseline with appearances at 28 days to assign a category of "improved" or "not improved". Patients with evidence of ongoing disease activity will receive a second infusion of canakinumab or placebo. Participants will be followed up for 90 days. Secondary outcomes include mortality and change in MELD score at 90 days.

DISCUSSION

This phase II study will explore the benefits of the IL-1β antibody, canakinumab, in the treatment of AH to provide proof of concept that inhibition of IL-1β signalling may improve histology and survival for patients with AH.

TRIAL REGISTRATION

EudraCT 2017-003724-79 . Prospectively registered on 13 April 2018.

POS0269-HPR CONTENT VALIDITY OF A MULTIPLE LANGUAGES QUESTIONNAIRE FOR MEASURING FLARE IN KNEE AND HIP OA: DEVELOPMENT OF THE FLARE-OA

Background:

Flare in osteoarthritis (OA) of the knee and hip (KHOA) is an important outcome for patients’ daily life and clinical research. A definition of a flare was set, and a core set of domains was recently endorsed by OMERACT/OARSI. No patient reported outcome (PRO) yet focusses on flare in OA specifically.

Objectives:

To develop a self-reporting instrument measuring flare in 5 languages, using qualitative methods and international Delphi consensus.

Methods:

We generated items using a dual-language (English and French) approach involving patients with OA from Australia, France and the United States and health care professionals (HCP) from international societies (OARSI, SFR, OMERACT). Item generation relied on semi-structured individual interviews conducted with OA patients and HCP and one focus group with patients. Content analysis allowed for identifying verbatim statements that were meaningful for patients and HCP. A Delphi consensus method was used to select the most relevant items, according to core domains set (OMERACT). A cross-cultural approach using current guidelines (1) was applied to produce Spanish (in Spain), Turkish and classical Arabic (in Morocco) versions using independent translation and expert committee to preserve its content validity.

Results:

From semi-structured interviews with 29 patients and 16 HCPs and one focus group with 10 patients, 180 statements in French (106) and English (77) were generated. Based on similarity or redundancy, 50 items with equivalent meaning in both languages were retained by an expert committee. After two Delphi rounds involving 50 patients and 116 HCPs from 17 countries on four continents, it was reduced to 33 items (response 0=not at all, to 10=absolutely) in five domains (pain, swelling, stiffness, consequences of symptoms and psychological aspects). This questionnaire was cross-culturally adapted into Spanish, Turkish and classical Arabic. The Spanish version uncovered one inappropriate item in the original questionnaire that was amended accordingly in all 5 languages.

Conclusion:

Flare is more than just an exacerbation of pain. The Flare-OA questionnaire includes all OMERACT recommended core domains. High content validity was seen in 2 original and 3 cross-culturally adapted languages. The Flare-OA should be considered as fit for purpose and evaluation of responsiveness in clinical studies in 5 languages.

Disclosure of Interests:

None declared

POS0270-HPR FLARE-OA QUESTIONNAIRE TO MEASURE FLARES IN OSTEOARTHRITIS OF THE KNEE AND HIP: ASSESSMENT OF ITS PSYCHOMETRIC PROPERTIES

Background:

Hip and knee OA is characterised by disease flares – understanding the determinants and consequences of OA flares has been hampered by lack of a standardized flare measure beyond the pain aspect. The patients point of view on the different aspect of their flares is essential.

Objectives:

The objective was to assess the psychometric properties of a new questionnaire for measuring the multidimensional aspect of flares in OA.

Methods:

Using a bilingual version of the questionnaire (33 items, response on a numeric scale, from 0 to 10), a multicentre survey (Australia, France and United States) was conducted on line with patients diagnosed with OA of the hip and/or the knee. Based on an international OMERACT/OARSI endorsed definition of the five core domains (pain, swelling, stiffness, consequences of symptoms and psychological aspects) composing a flare in OA [1], a confirmatory factorial analysis linked to the content analysis has been used to reduce the number of items and to determine the validity of the structure. The Flare-OA questionnaire (score from 0 to 100) has been tested in French and English for its internal consistency, its convergent validity with HOOS/KOOS and Mini-OAKHQOL questionnaires, and its discriminant validity.

Results:

Out of 398 patients (mean age 64 years old) who completed the questionnaire, 70.4% were female and 86.7% had knee OA. The confirmatory factorial analysis retained a model with 19 items (RMSEA =0.06; SRMR =0.04; CFI =0.96 and TLI = 0.94). The Cronbach Alpha was > 0.9 for the 5 domains and for the whole questionnaire. The correlations between the Flare-OA and the other instruments were in line with that hypothesis flare is related but different from other concepts usually measured. The discriminant validity was evidenced by a significant score difference (31.8; p<0,0001) between patients with and without flare, i.e. over twice the standard measurement error.

Conclusion:

The optimized Flare-OA questionnaire (19 items) is a reliable and valid instrument freely available from the authors for measuring the frequency and severity of flare in knee and hip OA in clinical research.

References:

[1]King LK, Epstein J, Cross M, et al. Establishing the Domains of Knee and Hip Osteoarthritis (OA) Flare: A Report from the OMERACT 2020 Inaugural Virtual Consensus Vote from the Flares in OA Working Group. (Submitted)

Disclosure of Interests:

None declared

FRI0403 CLINICAL FEATURES OF PROSTHETIC JOINT INFECTIONS DIFFER IN PATIENTS WITH INFLAMMATORY ARTHRITIS AND OSTEOARTHRITIS

Background:

Inflammatory arthritis (IA) patients are at increased risk for prosthetic joint infections (PJI). However, because active IA patients without infections can have elevated inflammatory markers that mimic joint infection, PJI diagnosis is challenging in this population.

Objectives:

We used an institutional PJI registry to identify and compare the clinical, microbiologic, and histopathologic features of culture positive (CP) and culture negative (CN) total hip and knee PJI in IA and OA patients. We also evaluated the relationship between culture positivity, IA, and clinical outcomes.

Methods:

A retrospective cohort of THA/TKA PJIs, from 2009 to 2016, were identified by ICD codes, and confirmed by chart review. IA diagnosis was also confirmed by use of IA-specific medications. CN cases were defined as PJIs with no evidence of microbial growth in intraoperative cultures and CP PJI cases were defined by positive microbial growth in intraoperative cultures. Treatment failure was defined as subsequent surgical treatment for infection after the initial infection surgery. H&E slides of OA and IA PJI cases matched by age (+/-5) sex, and culture status were reviewed by a pathologist for evidence of the histopathologic features listed in Table 2. Fisher’s exact test, chi-square test, and Kaplan-Meier estimates were used.

TABLE 1.

Patient characteristics in IA and OA PJIs

IAOAN%/SDN%/SDp-valueTotal36771Age58.511.466.812<.001BMI30.26.7306.70.861Female2877.833243.1<.001CCI2.81.71.72.10.002Smoking411.18611.20.792Glucorticoids1027.8395.1<.001Culture Negative1027.810914.10.024Treatment Success at 2 years1952.8509660.146

IA- inflammatory arthritis; OA – osteoarthritis; PJI -prosthetic joint infection; CCI – Charlson Comorbidity Index

TABLE 2.

Histopathology and clinical presentation in IA and OA PJIs

OA (N=57)IA (N= 31)CP-IA (N=23)CN-IA (N=8)N (%)p-valueN (%)p-valuePathology Review>10 PMN per HPF42 (74)22 (71)0.80620 (87)2 (25)0.003Chronic Inflammation13 (23)23 (74)0.00118 (78)5 (63)0.393Necrosis17 (30)9 (29)18 (35)1 (13)0.38Clinical PresentationMSIS50 (88)26 (84)0.74722 (96)4 (50)0.009Sinus Tract7 (12)7 (23)0.2335 (22)2 (25)1Elevated ESR or CRP41 (72)24 (77)0.62217 (74)7 (88)1Elevated Synovial WBC33 (58)19 (61)0.82313 (57)6 (75)1Elevated Synovial %PMN31 (54)20 (65)0.37714 (61)6 (75)0.333

OA – osteoarthritis; IA – inflammatory arthritis; CP – culture positive; CN – culture negative; MSIS – meets Musculoskeletal Infection Society diagnostic criteria

Results:

807 PJI cases were identified including 36 IA (33 RA and 3 SLE) and 771 OA. A higher proportion of IA PJI were CN (N=10, 27%) vs. OA PJI (N=109, 14%, p=0.02). IA-PJI were younger, female, on glucocorticoids, and with more comorbidities. Type of surgical treatment did not differ significantly between IA and OA groups. Comparing CN-IA vs. CP-IA, no difference was observed in age, smoking, diabetes, surgical treatment, IA-specific meds or Charlson comorbidities. One-year survivorship of CN-IA and CN-OA were 66% and 87% (p>0.05). Across all CP cases, 57% were staphylococcal, with no differences between groups. Treatment failure was more frequent for CP-IA (42%) compared to CP-OA (30%), (p=0.2).

Histopathology of 88 PJIs (31 IA and 57 OA) was reviewed. The IA cohort presented with more chronic inflammation (p=0.001) than the OA cohort. Within the IA cohort, a higher proportion of CP-IA had >10PMN per HPF (p= 0.003) and met MSIS criteria (p=0.009). Comparing CP-OA and CN-OA, there were no significant differences in histopathology findings or number of patients meeting MSIS criteria.

Conclusion:

IA PJIs are more likely to be culture negative than OA PJIs. Although our analysis was limited by our cohort size, our findings including differences in histopathology, and better clinical outcomes suggest the presence of biologic differences between CN and CP PJI that require further study.

Disclosure of Interests:

Milan Kapadia: None declared, Tania Pannellini: None declared, Carine Moezinia: None declared, Andy Miller: None declared, Mark Figgie: None declared, Peter Sculco: None declared, Michael Cross: None declared, Michael Henry: None declared, Linda Russell: None declared, Laura Donlin Consultant of: Consultant – Genentech/Roche, Allina Nocon: None declared, Susan Goodman Shareholder of: Reginosine- Investment, Grant/research support from: Novartis, Horizon, Consultant of: Novartis, Celgene, UCB

Ambiguity hindering self-management and prevention of osteoporosis in post-menopausal women

As osteoporosis relies largely on self-managed prevention and adherence to long-term treatment regimens, it is imperative that those at risk understand the disease that they are attempting to prevent. Ambiguity regarding osteoporosis and reluctance to take anti-osteoporosis medication (AOM) as well as calcium was noted in Australian post-menopausal women. This may lead to underestimating women's own risk of osteoporosis and fracture.

INTRODUCTION

Fragility fractures caused by osteoporosis have been known to inflict significant personal and financial burden on individuals and society. As treatment of osteoporosis relies largely on self-managed prevention and adherence to long-term AOM regimens, it is imperative that women have a sound understanding of the disease that they are attempting to prevent. Much can also be gained from qualitatively exploring the level of osteoporosis knowledge particularly in post-menopausal women who are at greater risk of osteoporosis and fractures. This study thus aims to determine what post-menopausal Australian women know about osteoporosis and osteoporosis prevention.

METHOD

Six focus group sessions, using purposive sampling, were conducted with 23 female participants (mean age 68 years (range 62-83)). Women responded to a series of open-ended questions regarding their knowledge about osteoporosis. The audiotaped focus groups were transcribed verbatim and analysed using a thematic analysis framework.

RESULTS

Three key themes were identified: ambiguity about the nature of osteoporosis, ambiguity about osteoporosis prevention and reluctance to take AOM and calcium.

CONCLUSION

Ambiguity associated with risk and prevention may provide women with a false sense of security that they are adequately acting to prevent the disease. Underestimation of their risk of osteoporosis and fracture as well as reluctance associated with AOM may be barriers to osteoporotic fracture prevention.

B and T cell prolymphocytic leukaemia

Prolymphocytic leukaemias B-PLL and T-PLL are rare disorders, typically with an aggressive clinical course and poor prognosis. Combining morphology, immunophenotyping, cytogenetic and molecular diagnostics reliably separates B-PLL and T-PLL from one another and other disorders. In T-PLL discovery of frequent mutations in the JAK-STAT pathway have increased understanding of disease pathogenesis. Alemtuzumab (anti-CD52) produces excellent response rates but long-term remissions are only achieved in a minority following consolidation with allogeneic stem cell transplant. Molecular abnormalities in B-PLL are less understood. Disruption of TP53 is a key finding, conveying chemotherapy resistance requiring novel therapies such as B-cell receptor inhibitors (BCRi). Both conditions require improved pathobiological knowledge to identify new treatment targets and guide therapy with novel pathway inhibitors.

Research protocol: The initiation, design and establishment of the Global Angelman Syndrome Registry

BACKGROUND

Angelman syndrome (AS) is a rare neurodevelopmental disorder affecting between 1 in 15 000 and 1 in 24 000 individuals. The condition results in severe developmental and expressive language delays, motor impairments and a unique behavioural phenotype consisting of excessive laughter, smiling and sociability. While many studies have contributed knowledge about the causes and natural history of the syndrome, large scale longitudinal studies are required to advance research and therapeutics for this rare syndrome.

METHOD

This article describes the protocol for the Global Angelman Syndrome Registry, and some initial findings. Due to the rarity of AS and the variability in symptom presentation, the registry team will strive for complete case ascertainment. Parents and caregivers will submit data to the registry via a secure internet connection. The registry consists of 10 modules that cover patient demographics; developmental, diagnostic, medical and surgical history, behaviour and development, epilepsy, medications and interventions and sleep.

RESULTS

Since its launch at https://angelmanregistry.info in September 2016, almost 470 individuals with AS have been signed up to the registry worldwide: 59% are from North and South America, 23% are from Europe, 17% are from the Asia Pacific region and 1% are from the Middle East or Africa. The majority of registrants are children, with only 16% aged over 20 years. Most participants indicated a chromosome deletion (76%), with fewer participants indicating a mutation, uniparental disomy or imprinting defect (20%).

CONCLUSION

Findings indicate a need to consider recruitment strategies that target caregivers of older children and adults, and parents and caregivers from non-English speaking backgrounds.

Dichloro-naphthoquinone as a non-classical inhibitor of the mycobacterial carbonic anhydrase Rv3588c

The soluble mycobacterial carbonic anhydrases Rv3588c and Rv1284 belong to a different class of carbonic anhydrases than those found in humans, making them attractive drug targets by using the inherent differences in the folds of the different classes. By screening a natural product library, we identified naphthoquinone derivatives as a novel non-classical inhibitor scaffold of mycobacterial carbonic anhydrases that lack the sulfonamide/sulfamate group and thus did not affect human carbonic anhydrase II.

Changes in quality of life associated with fragility fractures: Australian arm of the International Cost and Utility Related to Osteoporotic Fractures Study (AusICUROS)

We investigated change in health-related quality of life due to fracture in Australian adults aged over 50 years. Fractures reduce quality of life with the loss sustained at least over 12 months. At a population level, the loss was equivalent to 65 days in full health per fracture.

PURPOSE

We aimed to quantify the change in health-related quality of life (HRQoL) that occurred as a consequence of a fracture using the EQ-5D-3 L questionnaire.

METHODS

Adults aged ≥50 years with a low to moderate energy fracture were recruited from eight study centres across Australia. This prospective study included an 18-month follow-up of participants recruited within 2 weeks of a fracture (hip, wrist, humerus, vertebral and ankle). Information collected at baseline and 4, 12 and 18 months included characteristics of participants such as income level, education and prior fracture status. At 12 months post-fracture, the cumulative loss of quality of life was estimated using multivariate regression analysis to identify the predictors of HRQoL loss.

RESULTS

Mean HRQoL for all participants before fracture was 0.86, with wrist fracture having the highest pre-fracture HRQoL (0.90), while vertebral fracture had the lowest (0.80). HRQoL declined to 0.42 in the immediate post-fracture period. Only participants with a wrist, humerus or ankle fracture returned to their pre-fracture HRQoL after 18 months. An increased loss of HRQoL over 12 months was associated with HRQoL prior to the fracture, hospitalisation, education and fracture site. The multiple regression explained 30 % of the variation in the cumulative HRQoL loss at 12 months post-fracture for all fractures.

CONCLUSION

Low to moderate energy fractures reduce HRQoL, and this loss is sustained for at least 12 months or, in the case of hip and spine fractures, at least 18 months. At a population level, this represents an average loss of 65 days in full health per fragility fracture. This significant burden reinforces the need for cost-effective fracture prevention strategies.

Anxiety in early pregnancy: prevalence and contributing factors

Antenatal anxiety symptoms are not only a health problem for the expectant mother. Research has found that maternal anxiety may also have an impact on the developing baby. Therefore, it is important to estimate the prevalence of maternal anxiety and associated factors. The current study aims to estimate the prevalence of anxiety symptoms during the first trimester of pregnancy and to identify associated risk factors. Secondly, to investigate other factors associated with anxiety during early pregnancy including fear of childbirth and a preference for cesarean section. In a population-based community sample of 1,175 pregnant women, 916 women (78%) were investigated in the first trimester (gestation week 8-12). The Hospital Anxiety Depression Scale (HADS-A) was used to measure anxiety symptoms. The prevalence of anxiety symptoms (HADS-A scores≥8 during pregnancy) was 15.6% in early pregnancy. Women under 25 years of age were at an increased risk of anxiety symptoms during early pregnancy (OR 2.6, CI 1.7-4.0). Women who reported a language other than Swedish as their native language (OR 4.2, CI 2.7-7.0), reported high school as their highest level of education (OR 1.6, CI 1.1-2.3), were unemployed (OR 3.5, CI 2.1-5.8), used nicotine before pregnancy (OR 1.7, CI 1.1-2.5), and had a self-reported psychiatric history of either depression (OR 3.8, CI 2.6-5.6) or anxiety (OR 5.2, CI 3.5-7.9) before their current pregnancy were all at an increased risk of anxiety symptoms during early pregnancy. Anxiety symptoms during pregnancy increased the rate of fear of birth (OR 3.0, CI 1.9-4.7) and a preference for cesarean section (OR 1.7, CI 1.0-2.8). Caregivers should pay careful attention to history of mental illness to be able to identify women with symptoms of anxiety during early pregnancy. When presenting with symptoms of anxiety, the women might need counseling and or treatment in order to decrease her anxiety.

Reduced oxygen stress promotes propagation of murine postnatal enteric neural progenitors in vitro

BACKGROUND

Neural stem and progenitor cells of the Enteric Nervous System (ENS) are regarded as a novel cell source for applications in regenerative medicine. However, improvements to the current ENS cell culture protocols will be necessary to generate clinically useful cell numbers under defined culture conditions. Beneficial effects of physiologically low oxygen concentrations and/or the addition of anti-oxidants on propagation of various types of stem cells have previously been demonstrated. In this study, we tested the effects of such culture conditions on ENS stem and progenitor cell behavior.

METHODS

Enteric neural progenitor cells were isolated from postnatal day 3 mouse intestine and propagated either as monolayers or neurosphere-like bodies. The influence of hypoxic culture conditions and/or anti-oxidants on enteric cell propagation were studied systematically using proliferation, differentiation and apoptosis assays, whereas effects on gene expression were determined by qRT-PCR, western blot, and immunocytochemistry.

KEY RESULTS

Both hypoxic culture conditions and anti-oxidants supported a significantly improved enteric cell propagation and the generation of differentiated neural cell types. Enteric neural progenitors were shown to be specifically vulnerable to persistent oxidative stress.

CONCLUSIONS & INFERENCES

Our findings are consistent with previous reports of improved maintenance of brain stem cells cultured under reduced oxygen stress conditions and may therefore be applied to future cell culture protocols in ENS stem cell research.

Monitoring of WT1 expression in PB and CD34(+) donor chimerism of BM predicts early relapse in AML and MDS patients after hematopoietic cell transplantation with reduced-intensity conditioning

Relapse of malignant disease remains the major complication in patients with acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS) after hematopoietic cell transplantation (HCT) with reduced-intensity conditioning (RIC). In this study, we investigated the predictive value of disease-specific markers (DSMs), donor chimerism (DC) analysis of unsorted (UDC) or CD34(+) sorted cells and Wilms' tumor gene 1 (WT1) expression. Eighty-eight patients with AML or MDS were monitored after allogenic HCT following 2 Gy total-body irradiation with (n=84) or without (n=4) fludarabine 3 × 30 mg/m(2), followed by cyclosporin A and mycophenolate mofetil. DSMs were determined by fluorescence in situ hybridization (FISH) and WT1 expression by real-time polymerase chain reaction. Chimerism analysis was performed on unsorted or CD34(+) sorted cells, by FISH or short tandem repeat polymerase chain reaction. Twenty-one (24%) patients relapsed within 4 months after HCT. UDC, CD34(+) DC and WT1 expression were each significant predictors of relapse with sensitivities ranging from 53 to 79% and specificities of 82-91%. Relapse within 28 days was excluded almost entirely on the basis of WT1 expression combined with CD34(+) DC kinetics. Monitoring of WT1 expression and CD34(+) DC predict relapse of AML and MDS after RIC-HCT.

Genetic algorithm for shift-uncertainty correction in 1-D NMR-based metabolite identifications and quantifications

MOTIVATION

The analysis of metabolic processes is becoming increasingly important to our understanding of complex biological systems and disease states. Nuclear magnetic resonance spectroscopy (NMR) is a particularly relevant technology in this respect, since the NMR signals provide a quantitative measure of the metabolite concentrations. However, due to the complexity of the spectra typical of biological samples, the demands of clinical and high-throughput analysis will only be fully met by a system capable of reliable, automatic processing of the spectra. An initial step in this direction has been taken by Targeted Profiling (TP), employing a set of known and predicted metabolite signatures fitted against the signal. However, an accurate fitting procedure for (1)H NMR data is complicated by shift uncertainties in the peak systems caused by measurement imperfections. These uncertainties have a large impact on the accuracy of identification and quantification and currently require compensation by very time consuming manual interactions. Here, we present an approach, termed Extended Targeted Profiling (ETP), that estimates shift uncertainties based on a genetic algorithm (GA) combined with a least squares optimization (LSQO). The estimated shifts are used to correct the known metabolite signatures leading to significantly improved identification and quantification. In this way, use of the automated system significantly reduces the effort normally associated with manual processing and paves the way for reliable, high-throughput analysis of complex NMR spectra.

RESULTS

The results indicate that using simultaneous shift uncertainty correction and least squares fitting significantly improves the identification and quantification results for (1)H NMR data in comparison to the standard targeted profiling approach and compares favorably with the results obtained by manual expert analysis. Preservation of the functional structure of the NMR spectra makes this approach more realistic than simple binning strategies.