Janne Pitkäniemi

Off-Label Thrombolysis Is Not Associated With Poor Outcome in Patients With Stroke

Background and Purpose— Numerous contraindications included in the license of alteplase, most of which are not based on scientific evidence, restrict the portion of patients with acute ischemic stroke eligible for treatment with alteplase. We studied whether off-label thrombolysis was associated with poorer outcome or increased rates of symptomatic intracerebral hemorrhage compared with on-label use. Methods— All consecutive patients with stroke treated with intravenous thrombolysis from 1995 to 2008 at the Helsinki University Central Hospital were registered (n=1104). After excluding basilar artery occlusions (n=119), the study population included 985 patients. Clinical outcome (modified Rankin Scale 0 to 2 versus 3 to 6) and symptomatic intracerebral hemorrhage according to 3 earlier published criteria were analyzed with a logistic regression model adjusting for 21 baseline variables. Results— One or more license contraindications to thrombolysis was present in 51% of our patients (n=499). The most common of these were age >80 years (n=159), mild stroke National Institutes of Health Stroke Scale score <5 (n=129), use of intravenous antihypertensives prior to treatment (n=112), symptom-to-needle time >3 hours (n=95), blood pressure >185/110 mm Hg (n=47), and oral anticoagulation (n=39). Age >80 years was the only contraindication independently associated with poor outcome (OR, 2.18; 95% CI, 1.27 to 3.73) in the multivariate model. None of the contraindications were associated with an increased risk of symptomatic intracerebral hemorrhage. Conclusions— Off-license thrombolysis was not associated with poorer clinical outcome, except for age >80 years, nor with increased rates of symptomatic intracerebral hemorrhage. The current extensive list of contraindications should be re-evaluated when data from ongoing randomized trials and observational studies become available.

New susceptibility loci associated with kidney disease in Type 1 diabetes

Diabetic kidney disease, or diabetic nephropathy (DN), is a major complication of diabetes and the leading cause of end-stage renal disease (ESRD) that requires dialysis treatment or kidney transplantation. In addition to the decrease in the quality of life, DN accounts for a large proportion of the excess mortality associated with type 1 diabetes (T1D). Whereas the degree of glycemia plays a pivotal role in DN, a subset of individuals with poorly controlled T1D do not develop DN. Furthermore, strong familial aggregation supports genetic susceptibility to DN. However, the genes and the molecular mechanisms behind the disease remain poorly understood, and current therapeutic strategies rarely result in reversal of DN. In the GEnetics of Nephropathy: an International Effort (GENIE) consortium, we have undertaken a meta-analysis of genome-wide association studies (GWAS) of T1D DN comprising ∼2.4 million single nucleotide polymorphisms (SNPs) imputed in 6,691 individuals. After additional genotyping of 41 top ranked SNPs representing 24 independent signals in 5,873 individuals, combined meta-analysis revealed association of two SNPs with ESRD: rs7583877 in the AFF3 gene (P = 1.2×10−8) and an intergenic SNP on chromosome 15q26 between the genes RGMA and MCTP2, rs12437854 (P = 2.0×10−9). Functional data suggest that AFF3 influences renal tubule fibrosis via the transforming growth factor-beta (TGF-β1) pathway. The strongest association with DN as a primary phenotype was seen for an intronic SNP in the ERBB4 gene (rs7588550, P = 2.1×10−7), a gene with type 2 diabetes DN differential expression and in the same intron as a variant with cis-eQTL expression of ERBB4. All these detected associations represent new signals in the pathogenesis of DN.

Record-high incidence of Type I (insulin-dependent) diabetes mellitus in Finnish children

Aims/hypothesis. In Finland, the incidence of Type I (insulin-dependent) diabetes mellitus in children aged 14 years or under is the highest in the world and the trend in incidence has been increasing. Our aim was to determine the most recent trends in incidence and the age distribution at diagnosis of Type I diabetes. Methods. Data on the incidence of Type I diabetes in Finland nationwide were obtained from two sources: for the period 1965 to 1986 from the Central Drug Registry of the Social Insurance Institution and for the period 1987 to1996 from the prospective childhood Type I diabetes registry. The annual incidence was calculated per 100 000 people. The increase and the trend in incidence were estimated by fitting the linear regression model with the annual incidence data. Results. During 1987 to 1993 the incidence of Type I diabetes seemed to be rather stable at 36 per 100 000 per year. The incidence has continued to increase thereafter and reached 45 per 100 000 per year in 1996. The analysis of the long-term trend in incidence between 1965 and 1996 showed an absolute incidence increase of 0.67 per year on average being 3.4 % compared with the incidence in 1965. The increase from 1987 to 1996 was highest in very young children 1–4 years old at diagnosis. Conclusion/interpretation. The high incidence of Type I diabetes in Finnish children has thus far not levelled off but is increasing further. If the trend continues, the predicted incidence in Finland will be approximately 50 per 100 000 per year in the year 2010. [Diabetologia (1999) 42: 655–660]

Predicting outcome of IV thrombolysis–treated ischemic stroke patients The DRAGON score

Objective: To develop a functional outcome prediction score, based on immediate pretreatment parameters, in ischemic stroke patients receiving IV alteplase. Methods: The derivation cohort consists of 1,319 ischemic stroke patients treated with IV alteplase at the Helsinki University Central Hospital, Helsinki, Finland. We evaluated the predictive value of parameters associated with the 3-month outcome and developed the score according to the magnitude of logistic regression coefficients. We assessed accuracy of the model with bootstrapping. External validation was performed in a cohort of 330 patients treated at the University Hospital Basel, Basel, Switzerland. We assessed the score performance with area under the receiver operating characteristic curve (AUC-ROC). Results: The DRAGON score (0–10 points) consists of (hyper)Dense cerebral artery sign/early infarct signs on admission CT scan (both = 2, either = 1, none = 0), prestroke modified Rankin Scale (mRS) score >1 (yes = 1), Age (≥80 years = 2, 65–79 years = 1, <65 years = 0), Glucose level at baseline (>8 mmol/L [>144 mg/dL] = 1), Onset-to-treatment time (>90 minutes = 1), and baseline National Institutes of Health Stroke Scale score (>15 = 3, 10–15 = 2, 5–9 = 1, 0–4 = 0). AUC-ROC was 0.84 (0.80–0.87) in the derivation cohort and 0.80 (0.74–0.86) in the validation cohort. Proportions of patients with good outcome (mRS score 0–2) were 96%, 88%, 74%, and 0% for 0–1, 2, 3, and 8–10 points, respectively. Proportions of patients with miserable outcome (mRS score 5–6) were 0%, 2%, 5%, 70%, and 100% for 0–1, 2, 3, 8, and 9–10 points, respectively. External validation showed similar results. Conclusions: The DRAGON score is valid at our site and was reliable externally. It can support clinical decision-making, especially when invasive add-on strategies are considered. The score was not studied in patients with basilar artery occlusion. Further external validation is warranted.

Early Introduction of Dairy Products Associated with Increased Risk of IDDM in Finnish Children

Associations between infant-feeding patterns and risk of IDDM were investigated in a nationwide Finnish case-control study of 690 IDDM children <15 yr of age. Each child was matched by date of birth and sex to a randomly selected population-based control child. Univariate analysis revealed that the risk of IDDM was increased by ∼1.5 in children for whom breast-feeding was terminated at <2 mo of age, doubled in those who were exclusively breast-fed for <2 mo, and doubled in those who were introduced to dairy products at <2 mo of age. In further multivariate analyses of these factors, it was found that introduction of dairy products at an early age was the most important risk factor, and the observed univariate effects of duration of breast-feeding variables were explained by their correlation with this factor. This is the first observational study to show that early introduction of dairy products is independently associated with an increased risk of IDDM. Adjustment for mothers education and age, childs birth order, or birth weight did not affect the results.

Epigenome-wide association of DNA methylation markers in peripheral blood from Indian Asians and Europeans with incident type 2 diabetes: a nested case-control study.

BACKGROUND Indian Asians, who make up a quarter of the worlds population, are at high risk of developing type 2 diabetes. We investigated whether DNA methylation is associated with future type 2 diabetes incidence in Indian Asians and whether differences in methylation patterns between Indian Asians and Europeans are associated with, and could be used to predict, differences in the magnitude of risk of developing type 2 diabetes. METHODS We did a nested case-control study of DNA methylation in Indian Asians and Europeans with incident type 2 diabetes who were identified from the 8-year follow-up of 25 372 participants in the London Life Sciences Prospective Population (LOLIPOP) study. Patients were recruited between May 1, 2002, and Sept 12, 2008. We did epigenome-wide association analysis using samples from Indian Asians with incident type 2 diabetes and age-matched and sex-matched Indian Asian controls, followed by replication testing of top-ranking signals in Europeans. For both discovery and replication, DNA methylation was measured in the baseline blood sample, which was collected before the onset of type 2 diabetes. Epigenome-wide significance was set at p<1 × 10(-7). We compared methylation levels between Indian Asian and European controls without type 2 diabetes at baseline to estimate the potential contribution of DNA methylation to increased risk of future type 2 diabetes incidence among Indian Asians. FINDINGS 1608 (11·9%) of 13 535 Indian Asians and 306 (4·3%) of 7066 Europeans developed type 2 diabetes over a mean of 8·5 years (SD 1·8) of follow-up. The age-adjusted and sex-adjusted incidence of type 2 diabetes was 3·1 times (95% CI 2·8-3·6; p<0·0001) higher among Indian Asians than among Europeans, and remained 2·5 times (2·1-2·9; p<0·0001) higher after adjustment for adiposity, physical activity, family history of type 2 diabetes, and baseline glycaemic measures. The mean absolute difference in methylation level between type 2 diabetes cases and controls ranged from 0·5% (SD 0·1) to 1·1% (0·2). Methylation markers at five loci were associated with future type 2 diabetes incidence; the relative risk per 1% increase in methylation was 1·09 (95% CI 1·07-1·11; p=1·3 × 10(-17)) for ABCG1, 0·94 (0·92-0·95; p=4·2 × 10(-11)) for PHOSPHO1, 0·94 (0·92-0·96; p=1·4 × 10(-9)) for SOCS3, 1·07 (1·04-1·09; p=2·1 × 10(-10)) for SREBF1, and 0·92 (0·90-0·94; p=1·2 × 10(-17)) for TXNIP. A methylation score combining results for the five loci was associated with future type 2 diabetes incidence (relative risk quartile 4 vs quartile 1 3·51, 95% CI 2·79-4·42; p=1·3 × 10(-26)), and was independent of established risk factors. Methylation score was higher among Indian Asians than Europeans (p=1 × 10(-34)). INTERPRETATION DNA methylation might provide new insights into the pathways underlying type 2 diabetes and offer new opportunities for risk stratification and prevention of type 2 diabetes among Indian Asians. FUNDING The European Union, the UK National Institute for Health Research, the Wellcome Trust, the UK Medical Research Council, Action on Hearing Loss, the UK Biotechnology and Biological Sciences Research Council, the Oak Foundation, the Economic and Social Research Council, Helmholtz Zentrum Munchen, the German Research Center for Environmental Health, the German Federal Ministry of Education and Research, the German Center for Diabetes Research, the Munich Center for Health Sciences, the Ministry of Science and Research of the State of North Rhine-Westphalia, and the German Federal Ministry of Health.

Sex difference in the incidence of insulin-dependent diabetes mellitus: an analysis of the recent epidemiological data

Keywords: sex ratio; male-to-female ratio; insulin-dependent diabetes; incidence; epidemiology; geographical distribution

COMPLEMENT ACTIVATION ASSOCIATES WITH SACCULARCEREBRAL ARTERY ANEURYSM WALL DEGENERATION AND RUPTURE

OBJECTIVE Saccular cerebral artery aneurysm (SCAA) wall degeneration and inflammatory cell infiltrations associate with aneurysm rupture and subarachnoid hemorrhage, resulting in a devastating form of stroke. The complement system is the key mediator of inflammation and household processing of injured tissue. We studied how complement activation associates with SCAA wall degeneration and rupture to better understand the pathobiology of SCAA wall rupture. METHODS Unruptured (n = 26) and ruptured (n = 32) SCAA fundi resected after microsurgical clipping were studied by immunostaining for complement activation (membrane attack complex [MAC]) and by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling reaction for related cell death. Complement activation was correlated with clinical and other histological parameters. Electromicroscopy and immunoelectron microscopy were used for locating MAC depositions at the ultrastructural level. RESULTS MAC localized consistently in a decellularized layer in the outer SCAA wall, and was found in all SCAA samples. The percentage of MAC-positive area relative to the total SCAA wall surface area (range, 5-77%) was greater in ruptured (n = 25; median, 39%) than in unruptured SCAAs (n = 18; median, 20%; P = 0.005). It also associated significantly with SCAA wall degeneration (P < 0.001), de-endothelialization(P < 0.001), and CD163+ macrophage (P = 0.023) and T-lymphocyte (P = 0.030) infiltrations. Apoptotic terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling-positive nuclei and MAC were located at the same wall areas in four out of 14 double-stained samples, but no double-positive cells were found. Electromicroscopy and immunoelectron microscopy of an unruptured SCAA showed cell death in the MAC-positive layers in the outer SCAA wall. CONCLUSION These data suggests that complement activation and MAC formation are involved in SCAA wall degeneration and rupture.

Patient outcomes from symptomatic intracerebral hemorrhage after stroke thrombolysis

Objectives: To assess the impact of symptomatic intracerebral hemorrhage (sICH) on outcome of thrombolysis-treated ischemic stroke patients, as additional to recognized prognosticators. Methods: The study cohort included 985 ischemic stroke patients treated with IV thrombolysis at the Helsinki University Central Hospital (1995–2008). In a multivariable model adjusted for baseline stroke severity, age, onset-to-treatment time, baseline glucose, hyperdense cerebral artery sign, and early infarct signs on baseline imaging, and prior modified Rankin Scale (mRS), we calculated risk ratios (RRs) of patients with sICH (separately per Safe Implementation of Thrombolysis in Stroke[SITS]–Monitoring Study, European Cooperative Acute Stroke Study II [ECASS-II], and National Institute of Neurological Disorders and Stroke [NINDS] definitions) for poor 3-month outcome (mRS 3–6) and mortality. Receiver operating characteristic (ROC) curve and integrated discrimination improvement (IDI) evaluated impact of sICH on outcome. Internal cross-validation of the model was done with bootstrap statistics. Results: The frequency of sICH was 2.1% (SITS), 7.0% (ECASS-II), and 9.4% (NINDS). RRs for poor and fatal outcome, respectively, were 1.7 and 4.8 (SITS), 1.6 and 3.8 (ECASS-II), and 1.6 and 3.4 (NINDS). In IDI analyses, sICH improved prediction model for 3-month mRS of 3–6 and 4–6, respectively, by 1.4% and 3.0% (SITS), 4.0% and 5.9% (ECASS-II), and 4.7% and 6.1% (NINDS). In case of 3-month mRS 5–6 and mortality, it was 6.1% and 5.3% (SITS), 11.3% and 9.3% (ECASS-II), and 10.3% and 8.0% (NINDS). ROC analysis revealed similar results. Conclusions: Patients with sICH have increased risk of poor and fatal outcome. Compared with recognized stroke prognosticators, contribution of sICH is smaller. Definition-wise, ECASS-II- and NINDS-based sICH contribute relatively more; ECASS-II has the largest contribution to worst outcomes.

Association of serum cotinine level with a cluster of three nicotinic acetylcholine receptor genes (CHRNA3/CHRNA5/CHRNB4) on chromosome 15

A cluster of three nicotinic acetylcholine receptor genes on chromosome 15 (CHRNA5/CHRNA3/CHRNB4) has been shown to be associated with nicotine dependence and smoking quantity. The aim of this study was to clarify whether the variation at this locus regulates nicotine intake among smokers by using the level of a metabolite of nicotine, cotinine, as an outcome. The number of cigarettes smoked per day (CPD) and immune-reactive serum cotinine level were determined in 516 daily smokers (age 30-75 years, 303 males) from the population-based Health2000 study. Association of 21 SNPs from a 100 kb region of chromosome 15 with cotinine and CPD was examined. SNP rs1051730 showed the strongest association to both measures. However, this SNP accounted for nearly a five-fold larger proportion of variance in cotinine levels than in CPD (R(2) 4.3% versus 0.9%). The effect size of the SNP was 0.30 for cotinine level, whereas it was 0.13 for CPD. Variation at CHRNA5/CHRNA3/CHRNB4 cluster influences nicotine level, measured as cotinine, more strongly than smoking quantity, measured by CPD, and appears thus to be involved in regulation of nicotine levels among smokers.