One-stage dose-response meta-analysis for aggregated data

The standard two-stage approach for estimating non-linear dose-response curves based on aggregated data typically excludes those studies with less than three exposure groups. We develop the one-stage method as a linear mixed model and present the main aspects of the methodology, including model specification, estimation, testing, prediction, goodness-of-fit, model comparison, and quantification of between-studies heterogeneity. Using both fictitious and real data from a published meta-analysis, we illustrated the main features of the proposed methodology and compared it to a traditional two-stage analysis. In a one-stage approach, the pooled curve and estimates of the between-studies heterogeneity are based on the whole set of studies without any exclusion. Thus, even complex curves (splines, spike at zero exposure) defined by several parameters can be estimated. We showed how the one-stage method may facilitate several applications, in particular quantification of heterogeneity over the exposure range, prediction of marginal and conditional curves, and comparison of alternative models. The one-stage method for meta-analysis of non-linear curves is implemented in the dosresmeta R package. It is particularly suited for dose-response meta-analyses of aggregated where the complexity of the research question is better addressed by including all the studies.

Early life determinants of lung function change from childhood to adolescence

RATIONALE

Little is known about how perinatal and childhood factors influence lung function change between childhood and adolescence.

OBJECTIVES

To investigate possible early life predictors of change in FEV₁ between age 8 and 16 years. In addition, to investigate possible predictors of having persistently low lung function (FEV₁ <25th percentiles both at age 8 and 16) up to adolescence.

METHODS

The BAMSE birth cohort study collected data throughout childhood on environmental factors, individual characteristics, and spirometric measures at 8 and 16 years (n = 1425). Associations between early life predictors (n = 31) and FEV₁ increase between 8 and 16 years were assessed with linear regression. Predictors of having persistently low lung function were examined.

RESULTS

Few factors were consistently associated with altered lung function growth, although low birth weight, asthma heredity (paternal), secondhand smoke in infancy, and season of birth had a significant impact (p-value ≤0.01). The majority of subjects stayed however within the same category of lung function between ages 8 and 16 years (in total 821/1425 = 58%). Predictors associated with having persistently low lung function were gestational age, secondhand smoke (at 2 and 8 years of age), and factors related to lower respiratory tract infections in infancy.

CONCLUSIONS

In summary, rather few exposures in childhood were identified to have a significant impact on lung function growth between childhood and adolescence. Our data support previous study findings indicating that lung function development is influenced by factors before birth and in infancy, including second hand tobacco smoke.

Sense of coherence is a predictor of survival: A prospective study in women treated for breast cancer

OBJECTIVE

Sense of coherence (SOC) reflects a person's overall orientation to life. Sense of coherence guides the person in finding and utilizing resources to maintain health and manage stress. Previously, we demonstrated SOC's stability over time among breast cancer (BC) patients, and in the present article, SOC's predictive value for survival is tested.

METHODS

A cohort of 487 women underwent surgery for invasive BC and completed preoperatively the SOC-13 within a multicenter trial. Hazard ratios (HRs) were performed to identify significant independent predictors and their association with increase in SOC.

RESULTS

Over a median follow-up time of 10 years, patients with a higher SOC had 63% lower risk of BC progression (HR 0.63; 95% CI, 0.11 to 0.85, P .03), 80% lower risk of BC mortality (HR 0.80; 95% CI, 0.38 to 0.96, P .00), and 80% lower risk of all-cause mortality (HR 0.80; 95% CI, 0.47 to 0.93, P .00) than patients with a lower SOC. The mortality risk declined by 2.3% for every 1-unit increase in SOC, both for BC mortality (HR 0.98; 95% CI, 0.96 to 0.99, P .01) and for all-cause mortality (HR 0.98; 95% CI, 0.96 to 0.99, P .00). The risk of progression declined by 1.4% for every 1-unit increase in SOC (HR 0.99; 95% CI, 0.97 to 1.00, P .03).

CONCLUSIONS

This study provides evidence of SOC's predictive value for disease progression and BC-caused and all-cause mortality. Sense of coherence provides a complement when designing individual plans that aims to support patients during their treatment.

Haemodialysis access thrombosis: Outcomes after surgical thrombectomy versus catheter-directed thrombolytic infusion

Introduction:

Thrombosis is one of the most common complications of dialysis vascular access and is a significant source of morbidity and healthcare-associated costs. In this retrospective study, outcomes for surgical thrombectomy and thrombolysis after access thrombosis in patients with arteriovenous fistulas or prosthetic grafts (arteriovenous grafts) were analysed.

Methods:

All patients with a primary episode of dialysis access thrombosis between 2005 and 2013 were included which yielded 131 patients with 149 episodes of access thrombosis (108 arteriovenous grafts; 41 arteriovenous fistulas). In all, 18 patients had two separate accesses during the study. Patient demographics, access anatomy, surgical and radiological procedural data were recorded. Kaplan–Meier estimates and Poisson regression were used for statistical analysis of access patency.

Results:

In total, 107 underwent surgical thrombectomy and 42 were treated with catheter-directed thrombolytic infusion. Technical success was 60% for surgical thrombectomy and 73% for thrombolysis (p = 0.18). There were no major complications and no deaths within 30 days of the procedure. More patients had adjunctive procedures in the thrombolysis group (65/107 vs 37/42; p = 0.002). There was an increasing risk of rethrombosis or a further access-related event for both arteriovenous fistulas and arteriovenous grafts after open thrombectomy compared with catheter-directed thrombolytic infusion, and arteriovenous fistulas exhibited a lower risk than arteriovenous grafts with an average increase in risk of 23.9% (95% confidence interval: 3.1–49) between each treatment group.

Conclusion:

Thrombolysis for thrombosis of native and prosthetic dialysis accesses appears to yield better assisted primary patency compared to surgical thrombectomy. Our results suggest that thrombolysis may be considered the first-choice method for treating the thrombosed dialysis access.

Risk factors and prognosis for recurrent primary sclerosing cholangitis after liver transplantation: a Nordic Multicentre Study

OBJECTIVES

The risk for recurrent primary sclerosing cholangitis (rPSC) after liver transplantation is associated with inflammatory bowel disease (IBD). We assessed the frequency of rPSC and studied risk factors for recurrent disease with special focus on IBD. We also evaluated the importance of rPSC for prognosis.

MATERIALS AND METHODS

All liver transplanted PSC patients in the Nordic countries between 1984 and 2007 (n = 440), identified by the Nordic Liver Transplant Registry, were studied. Data were retrieved from patients' chart reviews. Multivariable Cox regression models were used to calculate risk factors for rPSC and death.

RESULTS

Of the 440 patients with a follow-up time after liver transplantation of 3743 patient years, rPSC was diagnosed in 19% (n = 85). Colectomy before liver transplantation was associated with a reduced risk of rPSC (HR 0.49; 95% CI, 0.26-0.94, p = 0.033). Neither high IBD activity nor presence of IBD flares before or after liver transplantation was associated with rPSC. Treatment with tacrolimus was an independent risk factor associated with increased risk for rPSC (HR, 1.81; 95% CI, 1.15-2.86, p = 0.010). The risk of dying or needing a re-transplantation after rPSC was increased in all age groups, but highest in patients transplanted before 40 years of age (HR 7.3; 95% CI, 4.1-12.8, p = 0.0001).

CONCLUSIONS

This study confirms that colectomy before liver transplantation is associated with a decreased risk of rPSC. Inflammatory activity of IBD was not associated with the risk of rPSC. Tacrolimus was an independent risk factor for PSC recurrence and its use as first line immunosuppression in PSC needs further study.

Restorative Surgery in Patients With Primary Sclerosing Cholangitis and Ulcerative Colitis Following a Colectomy

BACKGROUND

Studies on surgical procedures in patients with concomitant primary sclerosing cholangitis (PSC) and ulcerative colitis (UC) have mainly been restricted to single centers. The aim was to compare surgical treatment of UC with or without PSC in a nationwide study.

METHODS

A cohort study including all patients diagnosed with UC between 1987 and 2014 in Sweden was undertaken. The impact of PSC on the risk of colectomy, the chance of restorative surgery, and risk of failure (presence of a stoma) following restorative surgery were estimated. Survival analyses were performed using the Kaplan-Meier method and multivariable Cox regression models.

RESULTS

Of 49 882 UC patients, 2079 had a PSC diagnosis at the end of follow-up. The risk of colectomy was unaffected by PSC diagnosis, whereas the chance of restorative surgery was elevated in PSC-UC patients (hazard ratio [HR], 1.22; 95% confidence interval [CI], 1.02-1.44). Ileorectal anastomosis (IRA) was performed in 63% of the PSC-UC patients and 43% of the non-PSC-UC-patients, and the corresponding numbers for ileal pouch anal anastomosis (IPAA) were 35% and 53%. There was no significantly increased risk of failure following restorative surgery in PSC patients (HR, 1.44; 95% CI, 0.93-2.22). In PSC-UC patients, the cumulative failure rates following an IRA at 3 and 5 years were 15% and 18%, and following an IPAA they were 11% and 18%, respectively.

CONCLUSIONS

Presence of PSC is not associated with the risk of colectomy, whereas the chance of restorative surgery in PSC-UC patients is higher than in UC alone.

Body mass index status and peripheral airway obstruction in school-age children: a population-based cohort study

BACKGROUND

Few large prospective studies have investigated the impact of body mass index (BMI) on lung function during childhood.

METHODS

Using data collected between 2002 and 2013, we analysed associations between BMI status and lung function (assessed by spirometry) from 8 to 16 years, as well as cross-sectional associations with small airway function (impulse oscillometry) at 16 years in the BAMSE cohort (n=2889). At 16 years, cross-sectional associations with local and systemic inflammation were investigated by analysing FE_NO, blood eosinophils and neutrophils.

RESULTS

Overweight and obesity at 8 years were associated with higher FVC, but lower FEV₁/FVC ratio at 8 and 16 years. In boys, but not girls, obesity at 8 years was associated with a further reduction in FEV₁/FVC between 8 and 16 years. In cross-sectional analyses, overweight and obesity were associated with higher frequency dependence of resistance (R_5-20) and larger area under the reactance curve (AX^0.5) at 16 years. Increased blood neutrophil counts were seen in overweight and obese girls, but not in boys. No association was found between BMI status and FE_NO. Persistent, but not transient, overweight/obesity between 8 and 16 years was associated with higher R_5-20 and AX^0.5 and lower FEV₁/FVC (-2.8% (95% CI -4.1 to -1.2) in girls and -2.7% (95% CI -4.4 to -1.1) in boys) at 16 years, compared with persistent normal weight.

CONCLUSION

In childhood and adolescence, overweight and obesity, particularly persistent overweight, were associated with evidence of airway obstruction, including the small airways.

Surgical Treatment in Childhood-onset Inflammatory Bowel Disease-A Nationwide Register-based Study of 4695 Incident Patients in Sweden 2002-2014

BACKGROUND AND AIMS

The incidence of childhood-onset [< 18 years] inflammatory bowel disease [IBD] is increasing worldwide, and some studies suggest that it represents a more severe disease phenotype. Few nationwide, population-based studies have evaluated the surgical burden in patients with childhood-onset IBD, and whether the improved medical treatment has influenced the need for gastrointestinal surgery. The aim was to examine whether the surgical treatment at any age of patients with childhood-onset IBD has changed over time.

METHODS

In a nationwide cohort study we identified 4695 children [< 18 years] diagnosed with incident IBD in 2002-2014 through the Swedish Patient Register [ulcerative colitis: n = 2295; Crohn's disease: n = 2174; inflammatory bowel disease-unclassified: n = 226]. Abdominal [intestinal resections and colectomies] and perianal surgeries were identified through the Swedish Patient Register. The cumulative incidences of surgeries were calculated using the Kaplan-Meier method.

RESULTS

In the cohort, 44% were females and 56% males. The median age at inflammatory bowel disease diagnosis was 15 years and the maximum age at end of follow-up was 31 years. The 3-year cumulative incidence of intestinal surgery was 5% in patients with ulcerative colitis and 7% in patients with Crohn's disease, and lower in children aged < 6 years at inflammatory bowel disease diagnosis [3%] than in those aged 15-17 years at diagnosis [7%]. Calendar period of inflammatory bowel disease diagnosis was not associated with risk of surgery.

CONCLUSION

Over the past 13 years, the risk of surgery in childhood-onset inflammatory bowel disease has remained unchanged.

The impact of sepsis, delirium, and psychological distress on self-rated cognitive function in ICU survivors-a prospective cohort study

Background

Many intensive care unit (ICU) survivors develop psychological problems and cognitive impairment. The relation between sepsis, delirium, and later cognitive problems is not fully elucidated, and the impact of psychological symptoms on cognitive function is poorly studied in ICU survivors. The primary aim of this study was to examine the relationship between sepsis, ICU delirium, and later self-rated cognitive function. A second aim was to investigate the association between psychological problems and self-rated cognitive function 3 months after the ICU stay.

Methods

Patients staying more than 24 h at the general ICU at the Karolinska University Hospital Solna, Stockholm, Sweden, were screened for delirium with the Confusion Assessment Method-ICU (CAM-ICU) during their ICU stay. Sepsis incidence and severity were recorded. Three months later, 216 patients received the Cognitive Failures Questionnaire (CFQ), Hospital Anxiety and Depression Scale (HADS), and Post-Traumatic Stress Symptoms-10 (PTSS-10) questionnaires via postal mail.

Results

One hundred twenty-five patients (60%) responded to all questionnaires. Among respondents, the incidence of severe sepsis or septic shock was 42%. The overall incidence of delirium was 34%. Patients with severe sepsis/septic shock had a higher incidence of delirium, with an odds ratio (OR) of 3.7 (95% confidence interval (CI), 1.7–8.1). Self-rated cognitive problems 3 months post-ICU were found in 58% of the patients. We did not find any association between sepsis or delirium and late self-rated cognitive function. However, there was a correlation between psychological symptoms and self-rated cognitive function, with the strongest correlation between PTSS-10 scores and CFQ scores (r = 0.53; p < 0.001).

Conclusions

ICU delirium is more common in severely septic/septic shock patients. In our cohort, neither severe sepsis nor ICU delirium was associated with self-rated cognitive function 3 months after the ICU stay. Ongoing psychological symptoms, particularly post-traumatic stress was associated with worse self-rated cognitive function. Psychological symptoms need to be taken into account when assessing cognitive function in ICU survivors.

Colectomy prior to diagnosis of primary sclerosing cholangitis is associated with improved prognosis in a nationwide cohort study of 2594 PSC-IBD patients

BACKGROUND

Despite the close relationship between primary sclerosing cholangitis (PSC) and inflammatory bowel disease (IBD), the association between colectomy and the prognosis of PSC remains controversial.

AIM

To explore whether colectomy prior to PSC-diagnosis is associated with transplant-free survival.

METHODS

A nationwide cohort study in Sweden including all patients aged 18 to 69 years in whom both PSC and IBD was diagnosed between 1987 and 2014 was undertaken. Each patient was followed from date of both PSC and IBD diagnoses until liver transplantation or death, or 31 December 2014. Patients with colon in situ, and colectomy prior to PSC-diagnosis were compared. Survival analyses were performed using the Kaplan-Meier method and multivariable Cox regression models.

RESULTS

Of the 2594 PSC-IBD patients, 205 patients were treated with colectomy before PSC-diagnosis. During follow-up, liver transplantations were performed in 327 patients and 509 died. The risk of liver transplantation or death was lower in patients treated with colectomy prior to PSC-diagnosis (HR 0.71, 95% CI 0.53-0.95) than in patients with colon in situ. Male gender, longer time between IBD and PSC-diagnosis and older age were all associated with an increased risk of liver transplantation or death. Colectomy after PSC-diagnosis was however not associated with an increased risk of liver transplantation or death during long-term follow-up.

CONCLUSIONS

In PSC-IBD patients, colectomy prior to PSC-diagnosis is associated with a decreased risk of liver transplantation or death.

Oncology Nurses' Experiences With Patients Who Choose to Discontinue Cancer Chemotherapy

PURPOSE/OBJECTIVES

To describe the experiences of oncology nurses whose patients prematurely discontinue cancer chemotherapy.
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RESEARCH APPROACH

Qualitative, in-depth interviews.
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SETTING

Large oncology practice in South Carolina.
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PARTICIPANTS

Seven oncology nurses.
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METHODOLOGIC APPROACH

A general interview guide was used to obtain descriptions about nurses' experiences with patients who chose to discontinue chemotherapy. Interviews were analyzed using van Manen's approach to hermeneutic phenomenology.
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FINDINGS

Nurses experienced mixed emotions and struggled to balance their feelings with their respect for patient autonomy. Participants perceived that treatment side effects and inconvenience, advanced age, pessimistic attitude, and lack of social support influenced patients' decisions to discontinue treatment. 
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CONCLUSIONS

Findings indicate that nurses experience distress when patients prematurely discontinue treatment, and participants identified opportunities to support patients in continuing treatment.
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INTERPRETATION

Oncology nurses respect patients' rationales for discontinuing therapy and support their right to independent decision making. Nurses also struggle to cope with their reactions to patients' decisions. This tug of war somewhat parallels patients' struggles to balance quality of life with longevity.

Transcriptional mutagenesis reduces splicing fidelity in mammalian cells

Splicing fidelity is essential to the maintenance of cellular functions and viability, and mutations or natural variations in pre-mRNA sequences and consequent alteration of splicing have been implicated in the etiology and progression of numerous diseases. The extent to which transcriptional errors or lesion-induced transcriptional mutagenesis (TM) influences splicing fidelity is not currently known. To investigate this, we employed site-specific DNA lesions on the transcribed strand of a minigene splicing reporter in normal mammalian cells. These were the common mutagenic lesions O⁶-methylguanine (O⁶-meG) and 8-oxoguanine (8-oxoG). The minigene splicing reporters were derived from lamin A (LMNA) and proteolipid protein 1 (PLP1), both with known links to human diseases that result from deregulated splicing. In cells with active DNA repair, 1–4% misincorporation occurred opposite the lesions, which increased to 20–40% when repair was compromised. Furthermore, our results reveal that TM at a splice site significantly reduces in vivo splicing fidelity, thereby changing the relative expression of alternative splicing forms in mammalian cells. These findings suggest that splicing defects caused by transcriptional errors can potentially lead to phenotypic cellular changes and increased susceptibility to the development of disease.

F11 is associated with recurrent VTE in women

Genetic associations for the reoccurrence of venous thromboembolism (VTE) are not well described. Our aim was to investigate if common genetic variants, previously found to contribute to the prediction of first time thrombosis in women, were associated with risk of recurrence. The Thromboembolism Hormone Study (TEHS) is a Swedish nationwide case-control study (2002–2009). A cohort of 1,010 women with first time VTE was followed up until a recurrent event, death or November 2011. The genetic variants in F5 rs6025, F2 rs1799963, ABO rs514659, FGG rs2066865, F11 rs2289252, PROC rs1799810 and KNG1 rs710446 were assessed together with clinical variables. Recurrence rate was calculated as the number of events over the accumulated patient-time. Cumulative recurrence was calculated by Kaplan-Meier curve. Cox proportional-hazard model was used to estimate hazard ratios (HR) and 95 % confidence intervals (95 % CI) between groups. A total of 101 recurrent events occurred during a mean follow-up time of five years. The overall recurrence rate was 20 per 1,000 person-years (95 % CI; 16-24). The recurrence rate was highest in women with unprovoked first event and obesity. Carriers of the risk alleles of F5 rs6025 (HR=1.7 (95 % CI; 1.1–2.6)) and F11 rs2289252 (HR=1.8 (95 % CI; 1.1–3.0)) had significantly higher rates of recurrence compared to non-carriers. The cumulative recurrence was 2.5-fold larger in carriers of both F5 rs6025 and F11 rs2289252 than in non-carriers at five years follow-up. In conclusion, F5 rs6025 and F11 rs2289252 contributed to the risk of recurrent VTE and the combination is of potential clinical relevance for risk prediction.

Supplementary Material to this article is available online at www.thrombosis-online.com.

EULAR/ACR classification criteria for adult and juvenile idiopathic inflammatory myopathies and their major subgroups: a methodology report

OBJECTIVE

To describe the methodology used to develop new classification criteria for adult and juvenile idiopathic inflammatory myopathies (IIMs) and their major subgroups.

METHODS

An international, multidisciplinary group of myositis experts produced a set of 93 potentially relevant variables to be tested for inclusion in the criteria. Rheumatology, dermatology, neurology and paediatric clinics worldwide collected data on 976 IIM cases (74% adults, 26% children) and 624 non-IIM comparator cases with mimicking conditions (82% adults, 18% children). The participating clinicians classified each case as IIM or non-IIM. Generally, the classification of any given patient was based on few variables, leaving remaining variables unmeasured. We investigated the strength of the association between all variables and between these and the disease status as determined by the physician. We considered three approaches: (1) a probability-score approach, (2) a sum-of-items approach criteria and (3) a classification-tree approach.

RESULTS

The approaches yielded several candidate models that were scrutinised with respect to statistical performance and clinical relevance. The probability-score approach showed superior statistical performance and clinical practicability and was therefore preferred over the others. We developed a classification tree for subclassification of patients with IIM. A calculator for electronic devices, such as computers and smartphones, facilitates the use of the European League Against Rheumatism/American College of Rheumatology (EULAR/ACR) classification criteria.

CONCLUSIONS

The new EULAR/ACR classification criteria provide a patient's probability of having IIM for use in clinical and research settings. The probability is based on a score obtained by summing the weights associated with a set of criteria items.

Early psychological screening of intensive care unit survivors: a prospective cohort study

Background

A majority of patients survive their episode of critical illness but up to 30% of patients suffer from psychological problems such as post-traumatic stress, anxiety and depression in the year after intensive care unit (ICU) stay. A method to identify discharged patients at risk for adverse psychological outcome would be helpful in the triage for ICU follow-up and could enable early intervention. The aim of this study was to evaluate whether early screening with validated questionnaires after ICU discharge can identify patients at risk for symptoms of post-traumatic stress, anxiety and depression 3 months after ICU stay.

Methods

We performed a prospective observational cohort study in the general ICU at the Karolinska University Hospital Solna, Stockholm, Sweden. All adult patients surviving ≥ 24 hours in the ICU in a 9-month period were eligible for inclusion. Patients with mental disability, serious auditory and visual disorder, aphasia or who were unable to understand Swedish were excluded. One hundred and thirty-two patients were included and visited by a follow-up nurse within 1 week after ICU discharge. The Hospital Anxiety and Depression Scale (HADS) and the Post-Traumatic Stress Symptoms Checklist-10 (PTSS-10) were administered. Three months after ICU discharge the patients received the same questionnaires by postal mail. We assessed the predictive values of the questionnaires using the area under the receiver operating characteristic curve (AUROC). For correlation calculations, we used Spearman’s rank correlation coefficient. Negative and positive predictive values for each questionnaire were calculated.

Results

Eighty-two patients returned the follow-up questionnaires. We found correlation between early and late scores and reasonable predictive precision regarding 3-month outcomes, with an AUROC of 0.90 for PTSS-10 part B, 0.80 for the HADS anxiety subscale and 0.75 for the HADS depression subscale.

Conclusions

Symptoms of post-traumatic stress, anxiety and depression assessed 1 week after ICU stay correlate with 3-month psychological outcome. The HADS and PTSS-10 may be useful aids to identify ICU survivors at high risk for clinically significant symptoms of post-traumatic stress, anxiety and depression 3 months post ICU stay.

Relationship between fine particulate matter, weather condition and daily non-accidental mortality in Shanghai, China: A Bayesian approach

There are concerns that the reported association of ambient fine particulate matter (PM_2.5) with mortality might be a mixture of PM_2.5 and weather conditions. We evaluated the effects of extreme weather conditions and weather types on mortality as well as their interactions with PM_2.5 concentrations in a time series study. Daily non-accidental deaths, individual demographic information, daily average PM_2.5 concentrations and meteorological data between 2012 and 2014 were obtained from Shanghai, China. Days with extreme weather conditions were identified. Six synoptic weather types (SWTs) were generated. The generalized additive model was set up to link the mortality with PM_2.5 and weather conditions. Parameter estimation was based on Bayesian methods using both the Jeffreys’ prior and an informative normal prior in a sensitivity analysis. We estimate the percent increase in non-accidental mortality per 10 μg/m³ increase in PM_2.5 concentration and constructed corresponding 95% credible interval (CrI). In total, 336,379 non-accidental deaths occurred during the study period. Average daily deaths were 307. The results indicated that per 10 μg/m³ increase in daily average PM_2.5 concentration alone corresponded to 0.26–0.35% increase in daily non-accidental mortality in Shanghai. Statistically significant positive associations between PM_2.5 and mortality were found for favorable SWTs when considering the interaction between PM_2.5 and SWTs. The greatest effect was found in hot dry SWT (percent increase = 1.28, 95% CrI: 0.72, 1.83), followed by warm humid SWT (percent increase = 0.64, 95% CrI: 0.15, 1.13). The effect of PM_2.5 on non-accidental mortality differed under specific extreme weather conditions and SWTs. Environmental policies and actions should take into account the interrelationship between the two hazardous exposures.

2017 European League Against Rheumatism/American College of Rheumatology classification criteria for adult and juvenile idiopathic inflammatory myopathies and their major subgroups

OBJECTIVE

To develop and validate new classification criteria for adult and juvenile idiopathic inflammatory myopathies (IIM) and their major subgroups.

METHODS

Candidate variables were assembled from published criteria and expert opinion using consensus methodology. Data were collected from 47 rheumatology, dermatology, neurology and paediatric clinics worldwide. Several statistical methods were used to derive the classification criteria.

RESULTS

Based on data from 976 IIM patients (74% adults; 26% children) and 624 non-IIM patients with mimicking conditions (82% adults; 18% children), new criteria were derived. Each item is assigned a weighted score. The total score corresponds to a probability of having IIM. Subclassification is performed using a classification tree. A probability cut-off of 55%, corresponding to a score of 5.5 (6.7 with muscle biopsy) 'probable IIM', had best sensitivity/specificity (87%/82% without biopsies, 93%/88% with biopsies) and is recommended as a minimum to classify a patient as having IIM. A probability of ≥90%, corresponding to a score of ≥7.5 (≥8.7 with muscle biopsy), corresponds to 'definite IIM'. A probability of <50%, corresponding to a score of <5.3 (<6.5 with muscle biopsy), rules out IIM, leaving a probability of ≥50 to <55% as 'possible IIM'.

CONCLUSIONS

The European League Against Rheumatism/American College of Rheumatology (EULAR/ACR) classification criteria for IIM have been endorsed by international rheumatology, dermatology, neurology and paediatric groups. They employ easily accessible and operationally defined elements, and have been partially validated. They allow classification of 'definite', 'probable' and 'possible' IIM, in addition to the major subgroups of IIM, including juvenile IIM. They generally perform better than existing criteria.

2017 European League Against Rheumatism/American College of Rheumatology Classification Criteria for Adult and Juvenile Idiopathic Inflammatory Myopathies and Their Major Subgroups

OBJECTIVE

To develop and validate new classification criteria for adult and juvenile idiopathic inflammatory myopathies (IIM) and their major subgroups.

METHODS

Candidate variables were assembled from published criteria and expert opinion using consensus methodology. Data were collected from 47 rheumatology, dermatology, neurology, and pediatric clinics worldwide. Several statistical methods were utilized to derive the classification criteria.

RESULTS

Based on data from 976 IIM patients (74% adults; 26% children) and 624 non-IIM patients with mimicking conditions (82% adults; 18% children), new criteria were derived. Each item is assigned a weighted score. The total score corresponds to a probability of having IIM. Subclassification is performed using a classification tree. A probability cutoff of 55%, corresponding to a score of 5.5 (6.7 with muscle biopsy) "probable IIM," had best sensitivity/specificity (87%/82% without biopsies, 93%/88% with biopsies) and is recommended as a minimum to classify a patient as having IIM. A probability of ≥90%, corresponding to a score of ≥7.5 (≥8.7 with muscle biopsy), corresponds to "definite IIM." A probability of <50%, corresponding to a score of <5.3 (<6.5 with muscle biopsy), rules out IIM, leaving a probability of ≥50-<55% as "possible IIM."

CONCLUSION

The European League Against Rheumatism/American College of Rheumatology (EULAR/ACR) classification criteria for IIM have been endorsed by international rheumatology, dermatology, neurology, and pediatric groups. They employ easily accessible and operationally defined elements, and have been partially validated. They allow classification of "definite," "probable," and "possible" IIM, in addition to the major subgroups of IIM, including juvenile IIM. They generally perform better than existing criteria.

Scientific Opinion of the PPR Panel on the follow-up of the findings of the External Scientific Report 'Literature review of epidemiological studies linking exposure to pesticides and health effects'

In 2013, EFSA published a comprehensive systematic review of epidemiological studies published from 2006 to 2012 investigating the association between pesticide exposure and many health outcomes. Despite the considerable amount of epidemiological information available, the quality of much of this evidence was rather low and many limitations likely affect the results so firm conclusions cannot be drawn. Studies that do not meet the 'recognised standards' mentioned in the Regulation (EU) No 1107/2009 are thus not suited for risk assessment. In this Scientific Opinion, the EFSA Panel on Plant Protection Products and their residues (PPR Panel) was requested to assess the methodological limitations of pesticide epidemiology studies and found that poor exposure characterisation primarily defined the major limitation. Frequent use of case-control studies as opposed to prospective studies was considered another limitation. Inadequate definition or deficiencies in health outcomes need to be avoided and reporting of findings could be improved in some cases. The PPR Panel proposed recommendations on how to improve the quality and reliability of pesticide epidemiology studies to overcome these limitations and to facilitate an appropriate use for risk assessment. The Panel recommended the conduct of systematic reviews and meta-analysis, where appropriate, of pesticide observational studies as useful methodology to understand the potential hazards of pesticides, exposure scenarios and methods for assessing exposure, exposure-response characterisation and risk characterisation. Finally, the PPR Panel proposed a methodological approach to integrate and weight multiple lines of evidence, including epidemiological data, for pesticide risk assessment. Biological plausibility can contribute to establishing causation.

Dynamic Changes in Brain Mesenchymal Perivascular Cells Associate with Multiple Sclerosis Disease Duration, Active Inflammation, and Demyelination

Vascular changes, including blood brain barrier destabilization, are common pathological features in multiple sclerosis (MS) lesions. Blood vessels within adult organs are reported to harbor mesenchymal stromal cells (MSCs) with phenotypical and functional characteristics similar to pericytes. We performed an immunohistochemical study of MSCs/pericytes in brain tissue from MS and healthy persons. Post‐mortem brain tissue from patients with early progressive MS (EPMS), late stage progressive MS (LPMS), and healthy persons were analyzed for the MSC and pericyte markers CD146, platelet‐derived growth factor receptor beta (PDGFRβ), CD73, CD271, alpha‐smooth muscle actin, and Ki67. The MS samples included active, chronic active, chronic inactive lesions, and normal‐appearing white matter. MSC and pericyte marker localization were detected in association with blood vessels, including subendothelial CD146⁺PDGFRβ⁺Ki67⁺ cells and CD73⁺CD271⁺PDGFRβ⁺Ki67^– cells within the adventitia and perivascular areas. Both immunostained cell subpopulations were termed mesenchymal perivascular cells (MPCs). Quantitative analyses of immunostainings showed active lesions containing increased regions of CD146⁺PDGFRβ⁺Ki67⁺ and CD73⁺CD271⁺PDGFRβ⁺Ki67^– MPC subpopulations compared to inactive lesions. Chronic lesions presented with decreased levels of CD146⁺PDGFRβ⁺Ki67⁺ MPC cells compared to control tissue. Furthermore, LPMS lesions displayed increased numbers of blood vessels harboring greatly enlarged CD73⁺CD271⁺ adventitial and perivascular areas compared to control and EPMS tissue. In conclusion, we demonstrate the presence of MPC subgroups in control human brain vasculature, and their phenotypic changes in MS brain, which correlated with inflammation, demyelination and MS disease duration. Our findings demonstrate that brain‐derived MPCs respond to pathologic mechanisms involved in MS disease progression and suggest that vessel‐targeted therapeutics may benefit patients with progressive MS. Stem Cells Translational Medicine2017;6:1840–1851