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Background: Cardiac fibrosis stiffens the ventricular wall, predisposes to cardiac arrhythmias and contributes to the development of heart failure. In the present study, our aim was to identify novel miRNAs that regulate the development of cardiac fibrosis and could serve as potential therapeutic targets for myocardial fibrosis. Methods and results: Analysis for cardiac samples from sudden cardiac death victims with extensive myocardial fibrosis as the primary cause of death identified dysregulation of miR-185-5p. Analysis of resident cardiac cells from mice subjected to experimental cardiac fibrosis model showed induction of miR-185-5p expression specifically in cardiac fibroblasts. In vitro, augmenting miR-185-5p induced collagen production and profibrotic activation in cardiac fibroblasts, whereas inhibition of miR-185-5p attenuated collagen production. In vivo, targeting miR-185-5p in mice abolished pressure overload induced cardiac interstitial fibrosis. Mechanistically, miR-185-5p targets apelin receptor and inhibits the anti-fibrotic effects of apelin. Finally, analysis of left ventricular tissue from patients with severe cardiomyopathy showed an increase in miR-185-5p expression together with pro-fibrotic TGF-beta 1 and collagen I. Conclusions: Our data show that miR-185-5p targets apelin receptor and promotes myocardial fibrosis.

The European Society of Cardiology Guidelines on cardiac pacing from 2021 allow magnetic resonance imaging (MRI) in patients with cardiac implantable electronic devices (CIEDs) but do not recommend MRI in patients with epicardial pacing leads. The clinical dilemma remains whether performing an MRI in patients with CIED and epicardial leads is safe. We aimed to evaluate the safety of performing an MRI in patients with CIED and abandoned or functioning epicardial pacing leads.We included all adult patients who underwent clinically indicated MRIs with CIED and functioning or abandoned epicardial leads in a single tertiary hospital between November 2011 and October 2019. The data were retrospectively collected.Twenty-six MRIs were performed on 17 patients with functioning or abandoned epicardial pacing leads. Sixty-nine percent of the MRI scans (18/26) were conducted on patients with functioning epicardial pacing leads. A definite adverse event occurred in one MRI scan. This was a transient elevation of the pacing threshold in a patient with a functioning epicardial ventricular pacing lead implanted 29 years previously. An irreversible atrial pacing lead impedance elevation was detected 6 months after the MRI in another patient; the association with the previous MRI remained unclear. No adverse events were detected in MRIs performed on patients with modern (implanted in 2000 or later) functioning epicardial leads.MRIs in patients with CIED and modern functioning epicardial pacing leads were performed without detectable adverse events. Further large-scale studies are necessary to confirm MRI safety in patients with epicardial pacing leads.• Currently, MRI in patients with cardiac implantable electronic devices (CIEDs) and functioning or abandoned epicardial pacing leads is not recommended. • MRIs in patients with CIED and modern functioning epicardial leads (implanted in 2000 or later) were performed without detectable adverse events in our patient cohort. • Allowing MRI in patients with epicardial pacing leads may significantly improve the diagnostic work-up, especially in specific patient groups, such as patients with congenital heart disease.

Purpose: There is growing evidence that paradoxical embolism through patent foramen ovale (PFO) is a cause for cryptogenic stroke. However, it is still unclear why the foramen ovale fails to close after birth. We studied whether the 3D relations between the atrial septum (AS) and the inferior vena cava (IVC) are associated with PFO. Methods: We recruited 30 patients (18–49 years) with a first-ever cryptogenic stroke and 30 age- and sex-matched stroke-free controls. Using cardiac magnetic resonance, an approach to evaluate the 3D relations between the AS and the IVC was developed. The presence of interatrial right-to-left shunt was evaluated with transesophageal echocardiography (TEE) in patients and transcranial Doppler in controls. Results: Of 30 patients, 29 underwent successful TEE, of which 12 (41%) had a shunt. Patients with a shunt had a greater mean 3D angle (γ) between the atrial septal plane and the vector from the orifice of the IVC to the middle of the AS compared with patients without a shunt (45 ± 9° vs. 36 ± 8°, p = 0.017). Of 30 controls, 12 (40%) had a shunt and a greater mean γ compared with controls without a shunt (47 ± 8° vs. 37 ± 10°, p = 0.007). In a pooled analysis, 24 (41%) of 59 subjects with a shunt had a mean γ of 46 ± 9° compared with subjects without a shunt of 37 ± 9° (p < 0.001). Conclusions: More perpendicular orientation of the atrial septal plane to the orifice of the IVC is associated with PFO, possibly by directing the IVC flow to PFO.

Objectives: To determine the anti-inflammatory effect and safety of hydroxychloroquine after acute myocardial infarction. Method: In this multicenter, double-blind, placebo-controlled OXI trial, 125 myocardial infarction patients were randomized at a median of 43 h after hospitalization to receive hydroxychloroquine 300 mg (n = 64) or placebo (n = 61) once daily for 6 months and, followed for an average of 32 months. Laboratory values were measured at baseline, 1, 6, and 12 months. Results: The levels of interleukin-6 (IL-6) were comparable at baseline between study groups (p = 0.18). At six months, the IL-6 levels were lower in the hydroxychloroquine group (p = 0.042, between groups), and in the on-treatment analysis, the difference at this time point was even more pronounced (p = 0.019, respectively). The high-sensitivity C-reactive protein levels did not differ significantly between study groups at any time points. Eleven patients in the hydroxychloroquine group and four in the placebo group had adverse events leading to in-terruption or withdrawal of study medication, none of which was serious (p = 0.10, between groups). Conclusions: In patients with myocardial infarction, hydroxychloroquine reduced IL-6 levels significantly more than did placebo without causing any clinically significant adverse events. A larger randomized clinical trial is warranted to prove the potential ability of hydroxychloroquine to reduce cardiovascular endpoints after myocar-dial infarction. (c) 2021 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http:// creativecommons.org/licenses/by/4.0/).

International audience; Two methods are currently available for left atrial (LA) strain measurement by speckle tracking echocardiography, with two different reference timings for starting the analysis: QRS (QRS-LASr) and P wave (P-LASr). The aim of MASCOT HIT study was to define which of the two was more reproducible, more feasible, and less time consuming. In 26 expert centers, LA strain was analyzed by two different echocardiographers (young vs senior) in a blinded fashion. The study population included: healthy subjects, patients with arterial hypertension or aortic stenosis (LA pressure overload, group 2) and patients with mitral regurgitation or heart failure (LA volume–pressure overload, group 3). Difference between the inter-correlation coefficient (ICC) by the two echocardiographers using the two techniques, feasibility and analysis time of both methods were analyzed. A total of 938 subjects were included: 309 controls, 333 patients in group 2, and 296 patients in group 3. The ICC was comparable between QRS-LASr (0.93) and P-LASr (0.90). The young echocardiographers calculated QRS-LASr in 90% of cases, the expert ones in 95%. The feasibility of P-LASr was 85% by young echocardiographers and 88% by senior ones. QRS-LASr young median time was 110 s (interquartile range, IR, 78-149) vs senior 110 s (IR 78-155); for P-LASr, 120 s (IR 80-165) and 120 s (IR 90-161), respectively. LA strain was feasible in the majority of patients with similar reproducibility for both methods. QRS complex guaranteed a slightly higher feasibility and a lower time wasting compared to the use of P wave as the reference.

Background Up to 50% of ischemic strokes in the young after thorough diagnostic work-up remain cryptogenic or associated with low-risk sources of cardioembolism such as patent foramen ovale (PFO). We studied with cardiac magnetic resonance (CMR) imaging, whether left ventricular (LV) non-compaction-a possible source for embolic stroke due to sluggish blood flow in deep intertrabecular recesses-is associated with cryptogenic strokes in the young. Methods Searching for Explanations for Cryptogenic Stroke in the Young: Revealing the Etiology, Triggers, and Outcome (SECRETO; NCT01934725) is an international prospective multicenter case-control study of young adults (aged 18-49 years) presenting with an imaging-positive first-ever ischemic stroke of undetermined etiology. In this pilot substudy, 30 cases and 30 age- and sex-matched stroke-free controls were examined with CMR. Transcranial Doppler (TCD) bubble test was performed to evaluate the presence and magnitude of right-to-left shunt (RLS). Results There were no significant differences in LV volumes, masses or systolic function between cases and controls; none of the participants had non-compaction cardiomyopathy. Semi-automated assessment of LV non-compaction was highly reproducible. Non-compacted LV mass (median 14.0 [interquartile range 12.6-16.0] g/m2 vs. 12.7 [10.4-16.6] g/m2, p = 0.045), the ratio of non-compacted to compacted LV mass (mean 25.6 ± 4.2% vs. 22.8 ± 6.0%, p = 0.015) and the percentage of non-compacted LV volume (mean 17.6 ± 2.9% vs. 15.7 ± 3.8%, p = 0.004) were higher in cases compared to controls. In a multivariate conditional logistic regression model including non-compacted LV volume, RLS and body mass index, the percentage of non-compacted LV volume (odds ratio [OR] 1.55, 95% confidence interval [CI] 1.10-2.18, p = 0.011) and the presence of RLS (OR 11.94, 95% CI 1.14-124.94, p = 0.038) were independently associated with cryptogenic ischemic stroke. Conclusions LV non-compaction is associated with a heightened risk of cryptogenic ischemic stroke in young adults, independent of concomitant RLS and in the absence of cardiomyopathy. Clinical trial registration SECRETO; NCT01934725. Registered 4th September 2013. https://clinicaltrials.gov/ct2/show/NCT01934725.

BackgroundRecent studies suggest left atrial (LA) dysfunction in cryptogenic stroke. We studied the dynamics of right atrium (RA) and right atrial appendage (RAA) in young adults with cryptogenic stroke. We hypothesised that bi-atrial dysfunction and blood stagnation might contribute to thrombosis formation in patients with patent foramen ovale (PFO), as deep venous thrombosis is detected only in the minority of patients.MethodsThirty patients (aged 18–49) with a first-ever cryptogenic stroke and 30 age-matched and sex-matched stroke-free controls underwent cardiac magnetic resonance (CMR) imaging. An approach to estimate the RAA volume was developed, using crista terminalis and pectinate muscles as anatomical landmarks. Atrial expansion indices were calculated as (maximal volume – minimal volume) ×100%/minimal volume. Total pulmonary to systemic blood flow ratio (Qp/Qs) was based on phase contrast CMR. Right-to-left shunt (RLS) was evaluated with transoesophageal echocardiography in 29 patients and transcranial Doppler in 30 controls, moderate-to-severe RLS considered as clinically significant.ResultsWe found that RA and RAA volumes were similar between patients and controls. Also, RA expansion index was similar, but RAA (95.6%±21.6% vs 108.7%±25.8%, p=0.026) and LA (126.2%±28% vs 144.9%±36.3%, p=0.023) expansion indices were lower in patients compared with controls. Seven (24%) of 29 patients had an RLS compared with 1 (3%) of 30 controls (p=0.012). Among 59 study subjects, RLS was associated with lower RA (81.9%±15.9% vs 98.5%±29.5%, p=0.030), RAA (84.7%±18% vs 105.6%±24.1%, p=0.022), LA (109.8%±18.6% vs 140.1%±33.7%, p=0.017) and LAA (median 102.9% (IQR 65.6%–121.7%) vs 229.1% (151.8%–337.5%], p=0.002) expansion indices and lower Qp/Qs ratio (0.91±0.06 vs 0.98±0.07, p=0.027).ConclusionsThis study suggests bi-atrial dysfunction in young adults with cryptogenic stroke, associated with moderate-to-severe RLS. Dysfunction of the atria and atrial appendages may be an additional mechanism for PFO-related stroke.Trial registration numberNCT01934725.

PURPOSE Major histocompatibility complex (MHC) genes have been widely studied in adult inflammatory bowel disease (IBD), but data on MHC genes are scarce in pediatric IBD. This study focused on MHC association of genes with pediatric-onset IBD and its different phenotypes. METHODS Blood samples of 103 patients with pediatric IBD (Crohn disease or ulcerative colitis) were collected at Children's Hospital, University of Helsinki, Finland. HLA-A, -B, -DRB1 alleles and complement C4A and C4B gene copy numbers were determined and constructed into haplotypes by a Bayesian algorithm (PHASE). A general population cohort (n = 149) served as a control. HLA-alleles and C4 deficiency frequencies were compared between patients and controls with χ-squared and Fisher exact test with Bonferroni correction (Pcorr). RESULTS One MHC haplotype HLA-A03; HLA-B07; 1 C4A gene; 1 C4B gene; HLA-DRB115 was more common in Crohn disease and ulcerative colitis than in controls (7/61, 11.5%, 6/42, 14.3% and 1/149, 0.7%, respectively, odds ratio (OR) = 19.19, 95% CI 2.31-159.57, Pcorr = 0.004 for Crohn disease vs controls and OR = 24.67, 95% CI 2.88-211.36, Pcorr = 0.002 for ulcerative colitis vs controls). Two MHC markers were associated with clinical characteristics. HLA-DRB101 was more common in patients with milder disease course, that is, no need for anti-tumor necrosis factor (TNF)-α medication (18/32, 56.2% vs 19/71, 26.8% without and with anti-TNF-α medication, respectively, OR = 0.28, 95% CI 0.12-0.68, Pcorr = 0.032). C4B deficiency (

Background— The HLA-DRB1*01 allele of the human leukocyte antigen has been associated with acute coronary syndrome. Genome-wide association studies have revealed associations with human leukocyte antigen and non–human leukocyte antigen genes of 3 major histocompatibility complex gene classes but not at allelic level. Methods and Results— We conducted a large-scale genetic analysis on a case–control cohort comprising 5376 acute coronary syndrome cases and 4852 unrelated controls from 4 populations of 2 European countries. We analyzed the risk candidate allele of HLA-DRB1*01 by genomic real-time polymerase chain reaction together with high-density single nucleotide polymorphisms of the major histocompatibility complex to precisely identify risk loci for acute coronary syndrome with effective clinical implications. We found a risk haplotype for the disease containing single nucleotide polymorphisms from BTNL2 and HLA-DRA genes and the HLA-DRB1*01 allele. The association of the haplotype appeared in 3 of the 4 populations, and the direction of the effect was consistent in the fourth. Coronary samples from subjects homozygous for the disease-associated haplotype showed higher BTNL2 mRNA levels ( r =0.760; P + FOXP3 + regulatory T cell proliferation significantly (blocking versus nonblocking; P Conclusions— In cases with the risk haplotype for acute coronary syndrome, these results suggest involvement of enhanced immune reactions. BTNL2 may have an inhibitory effect on FOXP3 + T cell proliferation, especially in patients homozygous for the risk alleles. Clinical Trial Registration— https://www.clinicaltrials.gov ; Unique Identifier: NCT00417534.

The major histocompatibility complex (MHC; 6p21.3) contains the most polymorphic genes, the most gene dense parts, and the highest diversity of functional gene clusters of the human genome. The clusters form haplotypes, which differ in linkage disequilibrium and show large variations in strength and extent between populations. Haplotype cis- and trans-expression quantitative trait loci have increased the knowledge of regulatory interactions between multiple MHC genes. The detailed haplotype data offer a reference for future studies in immune-mediated diseases and may unravel disease associations in conditions traditionally considered not to be immunologic. This article aims to describe the structural and functional variations of the MHC genes and haplotypes and their role on selected immune-mediated diseases. In immune-/inflammation-mediated complex diseases, hundreds of common variants influence the development of the disease trait, but the individual variants have small effects on the disease phenotypes as seen in genome-wide association studies. The genetic influence may still be significant on the cellular or molecular level. Nonetheless, the HLA alone is not sufficient as a susceptible genetic background to deduce the disease. For a comprehensive insight of the disease mechanisms, both immunological and genome assays methods are required.

The major histocompatibility complex (MHC; 6p21.3) contains the most polymorphic genes, the most gene dense parts, and the highest diversity of functional gene clusters of the human genome. The clusters form haplotypes, which differ in linkage disequilibrium and show large variations in strength and extent between populations. Haplotype cis- and trans-expression quantitative trait loci have increased the knowledge of regulatory interactions between multiple MHC genes. The detailed haplotype data offer a reference for future studies in immune-mediated diseases and may unravel disease associations in conditions traditionally considered not to be immunologic. This article aims to describe the structural and functional variations of the MHC genes and haplotypes and their role on selected immune-mediated diseases. In immune-/inflammation-mediated complex diseases, hundreds of common variants influence the development of the disease trait, but the individual variants have small effects on the disease phenotypes as seen in genome-wide association studies. The genetic influence may still be significant on the cellular or molecular level. Nonetheless, the HLA alone is not sufficient as a susceptible genetic background to deduce the disease. For a comprehensive insight of the disease mechanisms, both immunological and genome assays methods are required.

Introduction Homozygous deficiencies of complement C4A or C4B are detected in 1-10% of populations. In genome-wide association studies C4 deficiencies are missed because the genetic variation of C4 is complex. There are no studies where the clinical presentation of these patients is analyzed. This study was aimed to characterize the clinical features of patients with homozygous C4A or C4B deficiency. Material and methods Thirty-two patients with no functional C4A, 87 patients with no C4B and 120 with normal amount of C4 genes were included. C4A and C4B numbers were assessed with genomic quantitative real-time PCR. Medical history was studied retrospectively from patients' files. Results Novel associations between homozygous C4A deficiency and lymphoma, coeliac disease and sarcoidosis were detected. These conditions were present in 12.5%, (4/32 in patients vs. 0.8%, 1/120, in controls, OR = 17.00, 95%Cl = 1.83-158.04, p = 0.007), 12.5% (4/32 in patients vs. 0%, 0/120 in controls, OR = 1.14, 95%Cl = 1.00-1.30, p = 0.002) and 12.5%, respectively (4/32 in patients vs. 2.5%, 3/120 in controls, OR = 5.571, 95%Cl = 1.79-2.32, p = 0.036). In addition, C4A and C4B deficiencies were both associated with adverse drug reactions leading to drug discontinuation (34.4%, 11/32 in C4A-deficient patients vs. 14.2%, 17/120 in controls, OR = 3.174, 95%Cl = 1.30-7.74, p = 0.009 and 28.7%, 25/87 in C4B-deficient patients, OR = 2.44, 95%Cl = 1.22-4.88, p = 0.010). Conclusion This reported cohort of homozygous deficiencies of C4A or C4B suggests that C4 deficiencies may have various unrecorded disease associations. C4 gene should be considered as a candidate gene in studying these selected disease associations.

SummaryComplement C4 genes are linked to paediatric inflammatory bowel disease (PIBD), but the mechanisms have remained unclear. We examined the influence of C4B gene number on intestinal microbiota and in-vitro serum complement activation by intestinal microbes in PIBD patients. Complement C4A and C4B gene numbers were determined by genomic reverse transcription–polymerase chain reaction (RT-PCR) from 64 patients with PIBD (Crohn's disease or ulcerative colitis). The severity of the disease course was determined from faecal calprotectin levels. Intestinal microbiota was assessed using the HITChip microarray. Complement reactivity in patients was analysed by incubating their sera with Yersinia pseudotuberculosis and Akkermansia muciniphila and determining the levels of C3a and soluble terminal complement complex (SC5b-9) using enzyme immunoassays. The microbiota diversity was wider in patients with no C4B genes than in those with one or two C4B genes, irrespective of intestinal inflammation. C4B and total C4 gene numbers correlated positively with soluble terminal complement complex (TCC, SC5b-9) levels when patient serum samples were stimulated with bacteria. Our results suggest that the C4B gene number associates positively with inflammation in patients with PIBD. Multiple copies of the C4B gene may thus aggravate the IBD-associated dysbiosis through escalated complement reactivity towards the microbiota.

Background & aims Elevated soluble HLA-DR (sHLA-DR) serum levels have been reported in HLA class II-associated inflammatory disorders. We have previously shown that the HLA class II allele HLA-DRB1*01 may predispose to acute coronary syndromes (ACS). To our knowledge, sHLA-DR serum levels have not been studied in ACS. Methods sHLA-DR serum levels were measured in 477 ACS patients as cases and 475 area- and sex-matched controls by sandwich enzyme-linked immunosorbent assay. Binary logistic regression and ordinal logistic regression analyses adjusted for clinical parameters were conducted to evaluate the associations of sHLA-DR levels. Results ACS patients had lower sHLA-DR serum levels compared to controls (OR = 0.837; 95% CI = 0.704–0.994; p = 0.043). After adjustment for smoking status, this association was no longer significant. This was explained by the notion that current smoking was inversely associated with sHLA-DR levels both in cases (OR = 0.592; 95% CI = 0.553–0.908; p = 0.016) and in controls (OR = 0.356; 95% CI = 0.226–0.563; p = 0.000010). A similar effect was not seen with other cardiovascular risk factors. Conclusions The results indicate, for the first time, that lower sHLA-DR levels are associated with smoking, but not with ACS. This is an important finding because previous studies of sHLA-DR have not accounted for the possible associations between smoking and sHLA-DR levels. Further studies are required to confirm these novel results and explore the mechanisms behind the observed associations.

Three-dimensional ultrasound is an emerging modality for the assessment of complex cardiac anatomy and function. The advantages of this modality include lack of ionizing radiation, portability, low cost, and high temporal resolution. Major limitations include limited field-of-view, reliance on frequently limited acoustic windows, and poor signal to noise ratio. This study proposes a novel approach to combine multiple views into a single image using an electromagnetic tracking system in order to improve the field-of-view. The novel method has several advantages: 1) it does not rely on image information for alignment, and therefore, the method does not require image overlap; 2) the alignment accuracy of the proposed approach is not affected by any poor image quality as in the case of image registration based approaches; 3) in contrast to previous optical tracking based system, the proposed approach does not suffer from line-of-sight limitation; and 4) it does not require any initial calibration. In this pilot project, we were able to show that using a heart phantom, our method can fuse multiple echocardiographic images and improve the field-of view. Quantitative evaluations showed that the proposed method yielded a nearly optimal alignment of image data sets in three-dimensional space. The proposed method demonstrates the electromagnetic system can be used for the fusion of multiple echocardiography images with a seamless integration of sensors to the transducer.

Background Major histocompatibility complex (MHC) gene region harbours haplotypes that associate with coronary artery disease (CAD). Their role in ST-elevation infarction (STEMI) or on the inflammatory level is not known. Methods Four candidate MHC markers were analyzed by real-time quantitative PCR and constructed into haplotypes from patients with STEMI ( n =162), matched controls with no CAD ( n =319) and general population sample ( n =149). High sensitivity C-reactive protein (hsCRP) was assessed in a follow-up visit from patients ( n =86) and at inclusion from other study subjects. Results The haplotype with one copy of HLA-DRB1*01, C4A , C4B but no HLA-B*35 doubled the risk of STEMI (OR=2.15, 95%CI=1.11–4.15, p =0.020 for patients vs. controls, and OR=2.26, 95%CI=0.97–5.24, p =0.052 for patients vs. population sample). The association between patients and controls persisted in multivariate analyses. The frequency of the haplotype was 5.86% ( n =19/324) in patients, 2.82% ( n =18/638) in controls and 2.68% ( n =8/298) in population sample. None of the individual MHC markers alone showed significant association with STEMI. In multivariate analyses, the haplotype carriers had higher hsCRP levels in patients (median 3.37mg/L in carriers vs. 1.14mg/L in non-carriers, p =0.019) and in controls (median 2.90mg/L vs. 1.21mg/L, p =0.009, respectively). Conclusion The MHC haplotype associates with STEMI and elevated baseline hsCRP levels. The results are in concordance with previous data on non-STEMI patients, implying that a HLA-DRB1*01 – related haplotype increases the risk of CAD, possibly though increased inflammation.

Purpose: To evaluate the efficacy of keratectomy in treating irregular astigmatism caused by peripheral hypertrophic subepithelial corneal degeneration (PHSD) and to study the possible underlying immunological risk factors. Materials and methods: Patients (14 eyes) with diagnosed PHSD were treated with superficial keratectomy with or without the assistance of phototherapeutic keratectomy (VisX S4; VisX Inc., Santa Ana, CA, USA). Thirteen patients were subjected to analysis of human leucocyte antigen (HLA) genes, complement C4 gene numbers and total plasma immunoglobulin levels. Immunological risk factors between patients and a control group comprising 150 individuals were compared. Results: The mean preoperative best spectacle corrected visual acuity (BCVA) improved from 0.16 ± 0.22 (LogMAR scale range 0–0.7) to 0.06 ± 0.13 (−0.1–0.4) (p

International audience; We present here the results of the Analysis of HLA Population Data (AHPD) project of the 16th International HLA and Immunogenetics Workshop (16IHIW) held in Liverpool in May-June 2012. Thanks to the collaboration of 25 laboratories from 18 different countries, HLA genotypic data for 59 new population samples (either well-defined populations or donor registry samples) were gathered and 55 were analysed statistically following HLA-NET recommendations. The new data included, among others, large sets of well-defined populations from north-east Europe and West Asia, as well as many donor registry data from European countries. The Gene[rate] computer tools were combined to create a Gene[rate] computer pipeline to automatically (i) estimate allele frequencies by an expectation-maximization algorithm accommodating ambiguities, (ii) estimate heterozygosity, (iii) test for Hardy-Weinberg equilibrium (HWE), (iv) test for selective neutrality, (v) generate frequency graphs and summary statistics for each sample at each locus and (vi) plot multidimensional scaling (MDS) analyses comparing the new samples with previous IHIW data. Intrapopulation analyses show that HWE is rarely rejected, while neutrality tests often indicate a significant excess of heterozygotes compared with neutral expectations. The comparison of the 16IHIW AHPD data with data collected during previous workshops (12th-15th) shows that geography is an excellent predictor of HLA genetic differentiations for HLA-A, -B and -DRB1 loci but not for HLA-DQ, whose patterns are probably more influenced by natural selection. In Europe, HLA genetic variation clearly follows a north to south-east axis despite a low level of differentiation between European, North African and West Asian populations. Pacific populations are genetically close to Austronesian-speaking South-East Asian and Taiwanese populations, in agreement with current theories on the peopling of Oceania. Thanks to this project, HLA genetic variation is more clearly defined worldwide and better interpreted in relation to human peopling history and HLA molecular evolution.

There was an error in the Competing Interests statement. The correct Competing interests are: MLL is working as a consultant at a company owned by the University of Helsinki providing complement C4 analysis for diagnostic samples. This does not alter the authors' adherence to all the PLoS ONE policies on sharing data and materials. The other authors have no competing interests to declare.

Low protein levels and copy number variation (CNV) of the fourth component of human complement (C4A and C4B) have been associated with various diseases. High-throughput methods for analysing C4 CNV are available, but they commonly do not detect the most common C4A mutation, a silencing CT insertion (CTins) leading to low protein levels. We developed a SYBR® Green labelled real-time quantitative polymerase chain reaction (qPCR) with a novel concentration range approach to address C4 CNV and deficiencies due to CTins. This method was validated in three sample sets and applied to over 1600 patient samples. CTins caused C4A deficiency in more than 70% (76/105) of the carriers. Twenty per cent (76/381) of patients with a C4A deficiency would have been erroneously recorded as having none, if the CTins had not been assessed. C4A deficiency was more common in patients than a healthy reference population, (OR = 1.60, 95%CI = 1.02–2.52, p = 0.039). The number of functional C4 genes can be straightforwardly analyzed by real-time qPCR, also with SYBR® Green labelling. Determination of CTins increases the frequency of C4A deficiency and thus helps to elucidate the genotypic versus phenotypic disease associations.

We sought to examine the role of complement component C4 deficiencies on the effect of antibiotic treatment in patients with acute coronary syndrome (ACS).Patients with ACS (n=144) were randomly divided to receive a three-month treatment of clarithromycin or placebo and followed for major adverse coronary and cerebrovascular events (MACCEs) for 404.5 median days (range 138-924 days). The primary results indicated that clarithromycin prevented recurrent cardiovascular attacks. For the present study we performed serum C4 allotyping of C4A and C4B. The clarithromycin response was reanalyzed taking into account the deficiencies in the C4 allotypes.The prevalence of C4A deficiency, C4B deficiency or these combined were 29.2% (42/144), 39.6% (57/144) and 66.0% (95/144), respectively. In patients with C4 deficiencies clarithromycin treatment resulted in a reduced number of MACCEs and the best cumulative survival as compared with the placebo group (MACCE 18.8% versus 39.1%, respectively; Log rank test, p=0.015).Only patients with ACS and C4 deficiencies seem to benefit from antibiotic treatment. This may explain the controversial results of secondary prevention trials of coronary artery disease and possibly serve as a pharmacogenomic marker for clarithromycin treatment.

BackgroundNon-tuberculous mycobacteria (NTM) are ubiquitous in the environment and they infect mainly persons with underlying pulmonary diseases but also previously healthy elderly women. Defects in host resistance that lead to pulmonary infections by NTM are relatively unknown. A few genetic defects have been associated with both pulmonary and disseminated mycobacterial infections. Rare disseminated NTM infections have been associated with genetic defects in T-cell mediated immunity and in cytokine signaling in families. We investigated whether there was an association between NTM infections and deficiencies of complement components C4A or C4B that are encoded by major histocompatibility complex (MHC).Methods50 adult patients with a positive NTM culture with symptoms and findings of a NTM disease were recruited. Patients' clinical history was collected and symptoms and clinical findings were categorized according to 2007 diagnostic criteria of The American Thoracic Society (ATS). To investigate the deficiencies of complement, C4A and C4B gene copy numbers and phenotype frequencies of the C4 allotypes were analyzed. Unselected, healthy, 149 Finnish adults were used as controls.ResultsNTM patients had more often C4 deficiencies (C4A or C4B) than controls (36/50 [72%] vs 83/149 [56%], OR = 2.05, 95%CI = 1.019-4.105, p = 0.042). C4 deficiencies for female NTM patients were more common than for controls (29/36 [81%] vs 55/100 [55%], OR = 3.39, 95% CI = 1.358-8.460, p = 0.007). C4 deficiences seemed not to be related to any specific underlying disease or C4 phenotype.ConclusionsC4 deficiency may be a risk factor for NTM infection in especially elderly female patients.