Prediction of the Values of CRP, eGFR, and Hemoglobin in the Follow-Up of Renal Cell Carcinoma Patients after (Cryo)Surgery Using Machine Learning Algorithms.

BACKGROUND: Artificial intelligence can support clinical decisions by predictive modeling. Using patient-specific characteristics, models may predict the course of clinical parameters, thus guiding monitoring approaches for the individual patient. Here, we present prediction models for inflammation and for the course of renal function and hemoglobin (Hb) in renal cell carcinoma patients after (cryo)surgery. METHODS: Using random forest machine learning in a longitudinal value-based healthcare data set (n = 86) of renal cell carcinoma patients, prediction models were established and optimized using random and grid searches. Data were split into a training and test set in a 70:30 ratio. Inflammation was predicted for a single timepoint, whereas for renal function estimated glomerular filtration rate (eGFR) and Hb time course prediction was performed. RESULTS: Whereas the last Hb and eGFR values before (cryo)surgery were the main basis for the course of Hb and renal function, age and several time frame features also contributed significantly. For eGFR, the type of (cryo)surgery was also a main predicting feature, and for Hb, tumor location, and body mass index were important predictors. With regard to prediction of inflammation no feature was markedly prominent. Inflammation prediction was based on a combination of patient characteristics, physiological parameters, and time frame features. CONCLUSIONS: This study provided interesting insights into factors influencing complications and recovery in individual renal cell carcinoma patients. The established prediction models provide the basis for development of clinical decision support tools for selection and timing of laboratory analyses after (cryo)surgery, thus contributing to quality and efficiency of care.

The MUC5B Promoter Polymorphism Associates With Severe COVID-19 in the European Population.

Background: Diversity in response on exposure to severe acute respiratory syndrome coronavirus 2 may be related to the innate immune response in the elderly. The mucin MUC5B is an important component of the innate immune response and expression levels are associated with the MUC5B promoter polymorphism, rs35705950. The high expressing T-allele is a risk allele for the non-infectious aging lung disease idiopathic pulmonary fibrosis (IPF). We investigated if MUC5B rs35705950 associates with severe COVID-19. Methods: In this retrospective candidate gene case-control study we recruited 108 Dutch patients (69% male, median age 66 years, 77% white) requiring hospitalization for COVID-19 (22% ICU stay, 24% died). For validation, genotypes were obtained from the UK-Biobank (n = 436, 57% male, median age 70 years, 27% died), for replication data from the severe COVID-19 GWAS group from Italy (n = 835) and Spain (n = 775) was used, each with a control cohort (n = 356,735, n = 1,255, n = 950, respectively). MUC5B association analysis was performed including adjustment for age and sex. Results: The rs35705950 T-allele frequency was significantly lower in Dutch white patients (n = 83) than in controls (0.04 vs. 0.10; p = 0.02). This was validated in the UK biobank cohort (0.08 vs. 0.11; p = 0.001). While age and sex differed significantly between cases and control, comparable results were obtained with age and sex as confounding variables in a multivariate analysis. The association was replicated in the Italian (p = 0.04), and Spanish (p = 0.03) case-control cohorts. Meta-analysis showed a negative association for the T-allele with COVID-19 (OR = 0.75 (CI: 0.67-0.85); p = 6.63 × 10-6). Conclusions: This study shows that carriage of the T-allele of MUC5B rs35705950 confers protection from development of severe COVID-19. Because the T-allele is a known risk allele for IPF, this study provides further evidence for the existence of trade-offs between optimal mucin expression levels in the aging lung.

Genetic Variation in CCL18 Gene Influences CCL18 Expression and Correlates with Survival in Idiopathic Pulmonary Fibrosis: Part A.

Idiopathic pulmonary fibrosis (IPF) is a progressive fibrotic disease, characterized by fibroblast proliferation and extracellular matrix deposition. CC-chemokine ligand 18 (CCL18) upregulates the production of collagen by lung fibroblasts and is associated with mortality. This study was designed to evaluate the influence of single nucleotide polymorphisms (SNPs) in the CCL18 gene on CCL18 expression and survival in IPF. Serum CCL18 levels and four SNPs in the CCL18 gene were analyzed in 77 Dutch IPF patients and 349 healthy controls (HCs). CCL18 mRNA expression was analyzed in peripheral blood mononuclear cells (PBMCs) from 18 healthy subjects. Survival analysis was conducted, dependent on CCL18-levels and -genotypes and validated in two German IPF cohorts (Part B). IPF patients demonstrated significantly higher serum CCL18 levels than the healthy controls (p < 0.001). Both in IPF patients and HCs, serum CCL18 levels were influenced by rs2015086 C > T genotype, with the highest CCL18-levels with the presence of the C-allele. Constitutive CCL18 mRNA-expression in PBMCs was significantly increased with the C-allele and correlated with serum CCL18-levels. In IPF, high serum levels correlated with decreased survival (p = 0.02). Survival was worse with the CT-genotype compared to the TT genotype (p = 0.01). Concluding, genetic variability in the CCL18-gene accounts for differences in CCL18 mRNA-expression and serum-levels and influences survival in IPF.

ACE and sIL-2R correlate with lung function improvement in sarcoidosis during methotrexate therapy.

INTRODUCTION: In sarcoidosis, the search for disease activity markers that correlate with treatment response is ongoing. The aim of this study was to investigate the pattern of two proposed markers, serum angiotensin-converting enzyme (ACE) and soluble IL-2 receptor (sIL-2R) during methotrexate (MTX) therapy in sarcoidosis patients. MATERIALS AND METHODS: We analysed 114 sarcoidosis patients who used MTX for six months, consisting of a subgroup of 76 patients with a pulmonary indication for treatment and a subgroup of 38 patients with an extra-pulmonary indication. ACE and sIL-2R serum levels were measured at baseline and after six months of treatment. Correlation coefficients (R) and odds ratios (ORs) were calculated to study the correlation and predictive effect of serum ACE and sIL-2R levels for pulmonary improvement. RESULTS: High baseline levels of ACE correlated significantly with lung function improvement after treatment (R = 0.45, p < 0.0001; stronger in the pulmonary subgroup R 0.57, p < 0.0001). ACE baseline levels >90 U/l predicted a 10% improvement in overall lung function (OR 3.55; CI 1.34-9.38), with the highest prediction level for 10% improvement in DLCO (OR 4.63; CI 1.23-17.4). After six months of MTX, mean ACE decreased with 17.2 U/l (p < 0.0001) and sIL-2R with 1850 pg/ml (p < 0.0001). Decreases in both ACE and sIL-2R correlated with an increase in lung function. The strongest correlation was found with change in DLCO in the pulmonary subgroup (ACE R = 0.63, P < 0.0001; sIL-2R R = 0.56, P < 0.0001). CONCLUSION: Baseline and serial serum ACE and sIL-2R levels correlate well with lung function improvement during MTX treatment. Serial measurements of these biomarkers are helpful in monitoring treatment effects in sarcoidosis patients.

[Hypoglycaemia with low insulin levels: what insulin tests do not measure]. / Hypoglykemieën met lage insulinewaarden: wat een insulinebepaling niet meet.

Insulin can be measured by immunochemical methods using polyclonal or monoclonal antibodies. Monoclonal antibodies are specific in the detection of pure human insulin, and may show little to no cross reactivity with pro-insulin or recombinant insulin. Polyclonal antibodies, however, do show such cross reactivity. Most medical laboratories use commercial (monoclonal) methods to measure insulin 75% of which are not capable of detecting pro-insulin or exogenous insulin. This pitfall in diagnostics may lead to prolonged uncertainty for both patient and physician, which we illustrate with two patients. The first patient was a 45-year-old woman with DM type 1 who for years suffered from hypoglycaemic attacks. Factitious hypoglycaemia went undiagnosed because our monoclonal assay did not detect the overdose insulin analogues. The second patient was a 47-year-old woman with recurrent hypoglycaemic attacks. An insulinoma, which produced pro-insulin, was only detected after using polyclonal insulin and specific pro-insulin assays.

IL1RN genetic variations and risk of IPF: a meta-analysis and mRNA expression study.

Idiopathic pulmonary fibrosis (IPF) is a rare and devastating lung disease of unknown aetiology. Genetic variations in the IL1RN gene, encoding the interleukin-1 receptor antagonist (IL-1Ra), have been associated with IPF susceptibility. Several studies investigated the variable number tandem repeat (VNTR) or single nucleotide polymorphisms rs408392, rs419598 and rs2637988, with variable results. The aim of this study was to elucidate the influence of polymorphisms in IL1RN on IPF susceptibility and mRNA expression. We performed a meta-analysis of the five case-control studies that investigated an IL1RN polymorphism in IPF in a Caucasian population. In addition, we investigated whether IL1RN mRNA expression was influenced by IL1RN polymorphisms. The VNTR, rs408392 and rs419598 were in tight linkage disequilibrium, with D' > 0.99. Furthermore, rs2637988 was in linkage disequilibrium with the VNTR (D' = 0.90). A haploblock of VNTR*2 and the minor alleles of rs408392and rs419598 was constructed. Meta-analysis revealed that this VNTR*2 haploblock is associated with IPF susceptibility both with an allelic model (odds ratio = 1.42, p = 0.002) and a carriership model (odds ratio = 1.60, p = 0.002). IL1RN mRNA expression was significantly influenced by rs2637988, with lower levels found in carriers of the (minor) GG genotype (p < 0.001). From this meta-analysis, we conclude that the VNTR*2 haploblock is associated with susceptibility to IPF. In addition, polymorphisms in IL1RN influence IL-1Ra mRNA expression, suggesting that lower levels of IL-1Ra predispose to developing IPF. Together these findings demonstrate that the cytokine IL-1Ra plays a role in IPF pathogenesis.

Association between variations in cell cycle genes and idiopathic pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a devastating and progressive lung disease. Its aetiology is thought to involve damage to the epithelium and abnormal repair. Alveolar epithelial cells near areas of remodelling show an increased expression of proapoptotic molecules. Therefore, we investigated the role of genes involved in cell cycle control in IPF. Genotypes for five single nucleotide polymorphisms (SNPs) in the tumour protein 53 (TP53) gene and four SNPs in cyclin-dependent kinase inhibitor 1A (CDKN1A), the gene encoding p21, were determined in 77 IPF patients and 353 controls. In peripheral blood mononuclear cells (PBMC) from 16 healthy controls mRNA expression of TP53 and CDKN1A was determined. Rs12951053 and rs12602273, in TP53, were significantly associated with survival in IPF patients. Carriers of a minor allele had a 4-year survival of 22% versus 57% in the non-carrier group (p = 0.006). Rs2395655 and rs733590, in CDKN1A, were associated with an increased risk of developing IPF. In addition, the rs2395655 G allele correlated with progression of the disease as it increased the risk of a rapid decline in lung function. Functional experiments showed that rs733590 correlated significantly with CDKN1A mRNA expression levels in healthy controls. This is the first study to show that genetic variations in the cell cycle genes encoding p53 and p21 are associated with IPF disease development and progression. These findings support the idea that cell cycle control plays a role in the pathology of IPF. Variations in TP53 and CDKN1A can impair the response to cell damage and increase the loss of alveolar epithelial cells.

Genetic polymorphisms and bronchiolitis obliterans syndrome after lung transplantation: promising results and recommendations for the future.

Survival rates after lung transplantation are the lowest among solid organ transplantations. Long-term survival is limited by the development of chronic rejection, known as bronchiolitis obliterans syndrome (BOS). Risk factors, such as acute rejection and cytomegalovirus infection, contribute to the development of BOS. However, these risk factors alone do not explain the interindividual variability seen in the development of BOS. There is growing evidence that genetic variations might contribute to an individual's susceptibility to rejection. In this systematic review, based on a literature search through Medline and Embase, an overview is given of the genetic polymorphisms that have been investigated in lung transplant recipients in relation to the devlopment of BOS. Functional genetic polymorphisms in the genes of IFNG (+874 A/T), TGFB1 (+915 G/C), and IL6 (-174 G/C) have been found to be associated with the development of BOS and allograft fibrosis after lung transplantation. However, confirmation was not consistent across all studied cohorts. Genetic polymorphisms in the genes of several Toll-like receptors, mannose-binding lectin, CD14, killer immunoglobulin-like receptors, and matrix metalloproteinase-7 were also found to be associated with the development of BOS, but these studies need to be replicated in independent cohorts. This review shows that there may be involvement of genetic polymorphisms in the development of BOS. Genetic risk profiling of lung transplant recipients could be a promising approach for the future, enabling individualized risk stratification and personalized immunosuppressive treatment after transplantation. Further studies are needed to define risk alleles.

Prognostic value of serum angiotensin-converting enzyme activity for outcome of community-acquired pneumonia.

BACKGROUND: In a previous study, a relation between decreased serum angiotensin-converting enzyme (ACE) activity and physiological parameters was observed in patients with community-acquired pneumonia. The present study aims to further assess the prognostic value of serum ACE activity for outcome of community-acquired pneumonia. METHODS: This was a prospective observational study including two cohorts of patients with community-acquired pneumonia (2004-2006; n=157 and 2007-2010; n=138). Serum ACE activity was measured at time of hospital admission. Based on reference values in healthy persons, patients were divided into subgroups of serum ACE activity: normal, low and extremely low. Physiological parameters, clinical outcomes and etiology were compared between the subgroups. RESULTS: A total of 265 patients were enrolled in this study. Mean age was 60±19 years. In patients with low serum ACE activity (<20 U/L, n=53), compared to patients with normal serum ACE activity (≥20 U/L, n=212), C-reactive protein (CRP) was significantly increased, systolic blood pressure was significantly lower and there was a trend for higher heart rate and leukocyte counts. Furthermore, Streptococcus pneumoniae was significantly more identified in patients with low serum ACE activity. Serum ACE activity <24 U/L was independently associated with bacteremia (adjusted OR 3.93 [95% CI 1.57-9.87]). Low serum ACE activity was not prognostic for length of hospital stay nor mortality. CONCLUSIONS: This study did not show prognostic value for serum ACE activity regarding clinical outcome in patients with community-acquired pneumonia. Serum ACE activity <24 U/L at time of hospitalization appeared an independent indicator for the presence of bacteremia. Further research should elucidate the role of ACE in systemic infection and sepsis during pneumonia.

Serum and BALF YKL-40 levels are predictors of survival in idiopathic pulmonary fibrosis.

BACKGROUND: The chitinase-like protein YKL-40 is a serum biomarker in diseases with fibrosis, inflammation and tissue remodelling. Idiopathic pulmonary fibrosis (IPF) is a progressive interstitial lung disease that is hallmarked by these processes. The aim of this study was to investigate the potential of YKL-40 as a prognostic biomarker for survival in IPF patients. METHODS: Serum and bronchoalveolar lavage fluid (BALF) levels of YKL-40 at the time of diagnosis and a promoter polymorphism in CHI3L1, the gene encoding YKL-40, were determined in 85 IPF patients and 126 controls. The relationship between YKL-40 levels and clinical parameters was evaluated. Kaplan-Meier and Cox regression analyses were used to examine the association between YKL-40 levels and survival. RESULTS: Serum and BALF YKL-40 levels were significantly higher in patients than in healthy controls (p < 0.001). The - 329 A/G polymorphism had a significant influence on BALF YKL-40 levels and the influence on serum YKL-40 levels showed a trend towards significance in IPF patients. IPF patients with high (> 79 ng/ml) serum or high BALF YKL-40 (> 17 ng/ml) levels had significantly shorter survival than those with low YKL-40 levels in serum or BALF. In patients with both low serum and low BALF YKL-40 levels no IPF related mortality was observed. Cox regression modelling showed that there were no confounding factors. CONCLUSIONS: The - 329 polymorphism was associated with serum and BALF YKL-40 levels in IPF patients. High serum and BALF YKL-40 levels are associated with poor survival in IPF patients and could be useful prognostic markers for survival in IPF.

Surfactant protein C mutations are the basis of a significant portion of adult familial pulmonary fibrosis in a dutch cohort.

RATIONALE: Familial clustering of adult idiopathic interstitial pneumonias (IIP) suggests that genetic factors might play an important role in disease development. Mutations in the gene encoding surfactant protein C (SFTPC) have been found in children and families with idiopathic pneumonias, whereas cocarriage of a mutation in ATP-binding cassette subfamily A member 3 (ABCA3) was postulated to have a disease-modifying effect. OBJECTIVES: To investigate the contribution of SFTPC mutations to adult familial pulmonary fibrosis (FPF) and the disease-modifying effect of mutations in ABCA3 within their families. METHODS: Twenty-two unrelated patients with FPF (10%) were identified within our single-center cohort of 229 patients with IIP. SFTPC was sequenced in 20 patients with FPF and 20 patients with sporadic IIP. In patients with an SFTPC mutation, sequencing of ABCA3 was performed. Discovered variants were typed in more than 100 control subjects and 121 additional patients with sporadic IIP. MEASUREMENTS AND MAIN RESULTS: In 5/20 unrelated patients with FPF (25%; confidence interval, 10-49) a mutation in SFTPC was detected: M71V, IVS4+2, and three times I73T. No mutations were detected in the sporadic or control cohort. Patients with SFTPC mutations presented with a histopathological pattern of usual interstitial pneumonia and nodular septa thickening and multiple lung cysts in combination with ground glass or diffuse lung involvement on chest high-resolution computed tomography. Two variants in ABCA3 were found in adult patients with FPF but not in affected children. CONCLUSIONS: Mutations in SFTPC are a frequent cause of FPF in adult patients in our cohort. Nonclassifiable radiological patterns with cystic changes and histopathological patterns of usual interstitial pneumonia are characteristics of adult SFTPC mutation carriers.

Polymorphisms in innate immunity genes associated with development of bronchiolitis obliterans after lung transplantation.

BACKGROUND: Activation of the immune system is suggested to prevent transplant tolerance and to promote the development of bronchiolitis obliterans syndrome (BOS). The innate immune system is activated by the interaction of pathogen-associated molecular patterns of microorganisms with Toll-like receptors (TLRs). Activation of innate immunity via TLRs was shown to be a barrier to the induction of transplantation tolerance after lung transplantation. We hypothesized that polymorphisms in 10 genes coding for TLR1 to TLR10 might contribute to an altered immune response and the subsequent development of BOS. METHODS: DNA was collected from 110 lung transplant recipients. Twenty patients developed BOS. The control group comprised 422 individuals. Sixty-four single-nucleotide polymorphisms (SNPs) in 10 genes coding for TLR1 to TLR10 were genotyped. RESULTS: The genotype distribution of TLR2 (rs1898830 and rs7656411), TLR4 (rs1927911) and TLR9 (rs352162 and rs187084) was significantly different between BOS(pos) patients and BOS(neg) patients and controls. The BOS(pos) group had significantly more patients with 3 or 4 of these risk alleles compared with the BOS(neg) and control groups. CONCLUSIONS: Polymorphisms in TLR2, TLR4 and TLR9 that recognize bacterial and viral pathogens are associated with BOS after lung transplantation.

Comparison of platelet function tests in predicting clinical outcome in patients undergoing coronary stent implantation.

Context High on-treatment platelet reactivity is associated with atherothrombotic events following coronary stent implantation. Objective To evaluate the capability of multiple platelet function tests to predict clinical outcome. Design, Setting, and Patients Prospective, observational, single-center cohort study of 1069 consecutive patients taking clopidogrel undergoing elective coronary stent implantation between December 2005 and December 2007. On-treatment platelet reactivity was measured in parallel by light transmittance aggregometry, Verify Now P2Y12 and Platelet works assays, and the IMPACT-R and the platelet function analysis system (PFA-100) (with the Dade PFA collagen/adenosine diphosphate (ADP) cartridge and Innovance PFA P2Y). Cutoff values for high on-treatment platelet reactivity were established by receiver operating characteristic curve (ROC) analysis. Main Outcome Measurement The primary end point was defined as a composite of all-cause death, nonfatal acute myocardial infarction, stent thrombosis, and ischemic stroke. The primary safety end point included TIMI (Thrombolysis In Myocardial Infarction) criteria major and minor bleeding. Results Kaplan-Meier analysis demonstrated that at 1-year follow-up, the primary end point occurred more frequently in patients with high on-treatment platelet reactivity when assessed by light transmittance aggregometry (52 [11.7%; 95% confidence interval {CI}, 8.9%-15.0%] vs 36 [6.0%;95%CI, 4.2%-8.2%] P.001; n=1049),Verify Now (54 [13.3%; 95% CI, 10.2%-17.0%] vs 37 [5.7%; 95% CI, 4.1%-7.8%]P.001; n=1052), Platelet works (33 [12.6%; 95% CI, 8.8%-17.2%] vs 21 [6.1%;95% CI, 3.8%-9.2%] P=.005; n=606), and Innovance PFA P2Y (18 [12.2%; 95%CI; 7.4%-18.6%] vs 28 [6.3%; 95% CI, 4.3%-8.9%] P=.02; n=588). ROC-curve analysis demonstrated that light transmittance aggregometry (area under the curve[AUC], 0.63; 95% CI, 0.58-0.68), Verify Now (AUC, 0.62; 95% CI, 0.57-0.67), and Platelet works (AUC, 0.61; 95% CI, 0.53-0.69) had modest ability to discriminate between patients with and without primary end point at 1-year follow-up. The IMPACT-R(n=905) and the Siemens PFA Collagen/ADP (n=812) were unable to discriminate between patients with and without the primary end point at 1-year follow-up (all AUCs included 0.50 in the CI). None of the tests identified patients at risk for bleeding. Conclusions Of the platelet function tests assessed, light transmittance aggregometry,Verify Now, Platelet works, and Innovance PFA P2Y were significantly associated with the primary end point. However, the predictive accuracy of these 4 tests was only modest. None of the tests provided accurate prognostic information to identify patients at higher risk of bleeding following stent implantation. Trial Registration clinical trials.gov Identifier: NCT00352014 [corrected].

MUC1 568 A/G genotype-dependent cancer antigen 15-3 levels in breast cancer patients.

OBJECTIVES: CA 15-3 is a widely used tumor marker for breast cancer. We have investigated whether the MUC1 568 A/G polymorphism can influence CA 15-3 levels in healthy women and patients with breast tumors. DESIGN AND METHODS: CA 15-3 was measured in 208 healthy women, in 67 with benign disease, and in 162 women with breast cancer. All subjects were genotyped for the MUC1 568 A/G polymorphism. RESULTS: Significant differences were observed between mean CA 15-3 levels of control subjects grouped according to the MUC1 568 genotype (mean+/-SD): AA (10.3+/-3.8), AG (15.9+/-5.0) and GG (19.0+/-5.6) U/mL, p<0.0001. Similar (median) results were observed in women with benign breast disease: AA (10.2), AG (14.2) and GG (16.6) U/mL, p<0.0001, and those with breast cancer: AA (10.4), AG (17.1) and GG (23.9) U/mL, p<0.0001. CONCLUSIONS: The MUC1 568 A/G polymorphism strongly influences CA 15-3 levels in healthy women and women with either benign or malignant breast tumors.

Angiotensin-converting enzyme insertion/deletion polymorphism and risk and outcome of pneumonia.

BACKGROUND: Recent studies have suggested involvement of the angiotensin-converting enzyme (ACE) insertion/deletion (I/D) polymorphism in the susceptibility to and severity of community-acquired pneumonia (CAP) in Asian populations. We have explored the hypothesis that the ACE I/D polymorphism affects the risk and outcome of CAP in a Dutch white population. METHODS: This is a hospital-based prospective observational study including patients with CAP admitted between October 2004 and August 2006. All patients were genotyped, and pneumonia severity and clinical outcome were compared between patients with II, ID, and DD genotypes of the ACE gene. Pneumonia severity was assessed on day of hospital admission and consecutively on days 2, 3, 5, and 10 of hospital stay using the acute physiology score (APS). Outcomes evaluated were duration of hospital stay, ICU admittance, and in-hospital and 28-day mortality rates. To study the association between ACE genotype and risk of pneumonia, the distribution of the ACE I/D polymorphism was compared with healthy control subjects from the same geographic region. RESULTS: In total, 200 patients with pneumonia and 200 control subjects were included in the study. Mean age of the patients was 63 years. APS scores were not different between the genotype groups on any of the days, and all clinical outcomes (duration of hospital stay, ICU admittance, in-hospital and 28-day mortality rates) were comparable between the three genotype groups. The ACE I/D genotype distribution was identical for patients and control subjects (p = 0.973). CONCLUSIONS: The ACE I/D polymorphism is not associated with risk and outcome of CAP in the Dutch white population.

Toll-like receptor 2 polymorphism is associated with preterm birth.

Evidence is increasing for a role of polymorphisms in maternal or fetal innate immune response genes in preterm birth. Toll-like receptors (TLRs) are important receptors in the innate immunity. The genotype distribution of two TLR2 single nucleotide polymorphisms (SNPs) and one TLR4 SNP were determined among 524 neonates and associated with gestational age (GA). Genomic DNA was isolated from prospectively collected blood samples and polymorphisms in TLR2 (T-16934A, RS4696480 and Arg753Gln, RS5743708) and TLR4 (Thr399Ile, RS4986791) were determined using sequence specific primers by PCR. Allele frequencies of two TLR2 SNPs and one TLR4 SNP were analyzed according to prematurity. Analysis among 305 infants, after exclusion of infants born after multiple pregnancy or because of preeclampsia, revealed significantly shorter GAs for infants carrying two polymorphic TLR2 alleles (-16934TA/AA and 753ArgGln/GlnGln) compared with infants carrying one polymorphic and one wild-type allele or two wild-type alleles (median GA 30.6 wk versus 34.1-36.8 wk, respectively, p < 0.02). Carriage of two variant TLR2 alleles potentially leads to aberrant innate immune responses, which may have contributed to very preterm birth.

Angiotensin-converting enzyme (ACE) I/D corrected serum ACE activity and severity assessment of community-acquired pneumonia.

BACKGROUND: Various studies have described decreased serum angiotensin-converting enzyme (ACE) activity in patients with pneumonia. The aim of the present study was to evaluate the role of ACE in pneumonia by comparing ACE insertion/deletion (I/D) genotype corrected serum ACE activity and to establish whether the severity of the disease correlates with lower ACE activity. METHODS: This was a prospective hospital-based observational study including 134 patients with pneumonia. Serum ACE activity was determined at admission, on days 2, 3, 5 and 10 of hospital stay, and at recovery. Based on ACE genotype and reference values, corresponding Z-scores were calculated. Disease severity, quantified by the acute physiology score (APS), and clinical outcome were compared between tertile groups of the Z-scores. RESULTS: A significant decrease in serum ACE activity during an episode of pneumonia with return to control range during recovery was observed for all three genotypes (II, ID and DD). The calculated Z-scores showed a negative correlation with APS scores (p=0.050). No significant association between decreased serum ACE activity and clinical outcome was observed. CONCLUSIONS: Serum ACE activity is significantly decreased during the acute phase of pneumonia. Despite correction for ACE I/D genotype, decreased ACE activity did not show a prognostic value. Further studies are needed to examine the mechanisms behind and diagnostic value of decreased ACE activity in community-acquired pneumonia.

Analysis of multiple SNPs in genetic association studies: comparison of three multi-locus methods to prioritize and select SNPs.

Nonparametric approaches have been developed that are able to analyze large numbers of single nucleotide polymorphisms (SNPs) in modest sample sizes. These approaches have different selection features and may not provide similar results when applied to the same dataset. Therefore, we compared the results of three approaches (set association, random forests and multifactor dimensionality reduction [MDR]) to select from a total of 93 candidate SNPs a subset of SNPs that are important in determining high-density lipoprotein (HDL)-cholesterol levels. The study population consisted of a random sample from a Dutch monitoring project for cardiovascular disease risk factors and was dichotomized into cases (low HDL-cholesterol, n = 533) and non-cases (high HDL-cholesterol, n = 545) based on gender-specific median values for HDL cholesterol. Clearly, all three approaches prioritized three SNPs as important (CETP Taq1B, CETP-629 C/A and LPL Ser447X). Two SNPs with weaker main effects were additionally prioritized by random forests (APOC3 3175 G/C and CCR2 Val62Ile), whereas MTHFR 677 C/T was selected in combination with CETP Taq1B as best model by MDR. Obtained p-values for the selected models were significant for the set association approach (p =.0019), random forests (p<.01) and MDR (p<.02). In conclusion, the application of a combination of multi-locus methods is a useful approach in genetic association studies to select a well-defined set of important SNPs for further statistical and epidemiological interpretation, providing increased confidence and more information compared with the application of only one method.

A CHI3L1 gene polymorphism is associated with serum levels of YKL-40, a novel sarcoidosis marker.

BACKGROUND: YKL-40, a chitinase-like cartilage glycoprotein, has recently shown its potential as a marker for sarcoidosis. METHODS: This study aimed to assess whether YKL-40 at presentation may predict the course of sarcoidosis over a 4-year follow-up period and to investigate whether polymorphisms in the chitinase 3-like 1 (CHI3L1) gene might influence serum YKL-40 levels in sarcoidosis patients (n=63) and controls (n=333). RESULTS: Patients had significantly higher (mean, 95% CI) serum YKL-40 levels (181.3 ng/ml, 50.7-648.1) compared to controls (36.6 ng/ml, p<0.0001. Serum YKL-40 was elevated in 79% of the patients and was inversely correlated with DLco at presentation (r(2)=-0.27, p=0.03), but not after 2-4 years of follow-up (r(2)=-0.16, p=0.27). Serum YKL-40 levels in controls were dependent on the CHI3L1 -329 G/A polymorphism (mean, 95% CI): GG (n=213) 48.3 ng/ml, 41.7-56.0; GA (n=101) 31.2 ng/ml, 26.6-36.3; AA (n=17) 17.8 ng/ml, 13.6-23.4, p<0.0001. In patients, this effect was not observed. CONCLUSIONS: YKL-40 may be used as a sarcoidosis disease marker, but it is unsuitable as a marker to predict the course of the disease. The CHI3L1 -329 G/A polymorphism contributes to inter-individual variations of YKL-40 levels, but does not influence sarcoidosis disease susceptibility or severity.