Maria Cristina Monti

NOS1AP Is a Genetic Modifier of the Long-QT Syndrome

Background— In congenital long-QT syndrome (LQTS), a genetically heterogeneous disorder that predisposes to sudden cardiac death, genetic factors other than the primary mutation may modify the probability of life-threatening events. Recent evidence indicates that common variants in NOS1AP are associated with the QT-interval duration in the general population. Methods and Results— We tested the hypothesis that common variants in NOS1AP modify the risk of clinical manifestations and the degree of QT-interval prolongation in a South African LQTS population (500 subjects, 205 mutation carriers) segregating a founder mutation in KCNQ1 (A341V) using a family-based association analysis. NOS1AP variants were significantly associated with the occurrence of symptoms (rs4657139, P=0.019; rs16847548, P=0.003), with clinical severity, as manifested by a greater probability for cardiac arrest and sudden death (rs4657139, P=0.028; rs16847548, P=0.014), and with greater likelihood of having a QT interval in the top 40% of values among all mutation carriers (rs4657139, P=0.03; rs16847548, P=0.03). Conclusions— These findings indicate that NOS1AP, a gene first identified as affecting the QTc interval in a general population, also influences sudden death risk in subjects with LQTS. The association of NOS1AP genetic variants with risk for life-threatening arrhythmias suggests that this gene is a genetic modifier of LQTS, and this knowledge may be clinically useful for risk stratification for patients with this disease, after validation in other LQTS populations.

Molecular amino acid signatures in the MHC class II peptide-binding pocket predispose to autoimmune thyroiditis in humans and in mice

Hashimotos thyroiditis (HT) is associated with HLA, but the associated allele is still controversial. We hypothesized that specific HLA-DR pocket-sequence variants are associated with HT and that similar variants in the murine I-E locus (homologous to HLA-DR) predispose to experimental autoimmune thyroiditis (EAT), a classical mouse model of HT. Therefore, we sequenced the polymorphic exon 2 of the HLA-DR gene in 94 HT patients and 149 controls. In addition, we sequenced exon 2 of the I-E gene in 22 strains of mice, 12 susceptible to EAT and 10 resistant. Using logistic regression analysis, we identified a pocket amino acid signature, Tyr-26, Tyr-30, Gln-70, Lys-71, strongly associated with HT (P = 6.18 × 10−5, OR = 3.73). Lys-71 showed the strongest association (P = 1.7 × 10−8, OR = 2.98). This association was seen across HLA-DR types. The 5-aa haplotype Tyr-26, Tyr-30, Gln-70, Lys-71, Arg-74 also was associated with HT (P = 3.66 × 10−4). In mice, the I-E pocket amino acids Val-28, Phe-86, and Asn-88 were strongly associated with EAT. Structural modeling studies demonstrated that pocket P4 was critical for the development of HT, and pockets P1 and P4 influenced susceptibility to EAT. Surprisingly, the structures of the HT- and EAT-susceptible pockets were different. We conclude that specific MHC II pocket amino acid signatures determine susceptibility to HT and EAT by causing structural changes in peptide-binding pockets that may influence peptide binding, selectivity, and presentation. Because the HT- and EAT-associated pockets are structurally different, it is likely that distinct antigenic peptides are associated with HT and EAT.

Shared molecular amino acid signature in the HLA-DR peptide binding pocket predisposes to both autoimmune diabetes and thyroiditis

There is strong genetic association between type 1A diabetes (T1D) and autoimmune thyroid disease (AITD). T1D and AITD frequently occur together in the same individual, a condition classified as a variant of the autoimmune polyglandular syndrome type 3 (APS3). Because T1D and AITD are individually strongly associated with different HLA class II sequences, we asked which HLA class II pocket sequence and structure confer joint susceptibility to both T1D and AITD in the same individual (APS3v). We sequenced the HLA-DR gene in 105 APS3v patients and 153 controls, and identified a pocket amino acid signature, DRβ-Tyr-26, DRβ-Leu-67, DRβ-Lys-71, and DRβ-Arg-74, that was strongly associated with APS3v (P = 5.4 × 10−14, odds ratio = 8.38). Logistic regression analysis demonstrated that DRβ-Leu-67 (P = 9.4 × 10−13) and DRβ-Arg-74 (P = 1.21 × 10−13) gave strong independent effects on disease susceptibility. Structural modeling studies demonstrated that pocket 4 was critical for the development of T1D+AITD; all disease-associated amino acids were linked to areas of the pocket that interact directly with the peptide and, therefore, influence peptide binding. The disease-susceptible HLA-DR pocket was more positively charged (Lys-71, Arg-74) compared with the protective pocket (Ala-71, Gln-74). We conclude that a specific pocket amino acid signature confers joint susceptibility to T1D+AITD in the same individual by causing significant structural changes in the MHC II peptide binding pocket and influencing peptide binding and presentation. Moreover, Arg-74 is a major amino acid position for the development of several autoimmune diseases. These findings suggest that blocking the critical Arg-74 pocket might offer a method for treating certain autoimmune conditions.

Identification of a KCNQ1 Polymorphism Acting as a Protective Modifier against Arrhythmic Risk in Long QT Syndrome

Background—Long-QT syndrome (LQTS) is characterized by such striking clinical heterogeneity that, even among family members carrying the same mutation, clinical outcome can range between sudden death and no symptoms. We investigated the role of genetic variants as modifiers of risk for cardiac events in patients with LQTS. Methods and Results—In a matched case–control study including 112 patient duos with LQTS from France, Italy, and Japan, 25 polymorphisms were genotyped based on either their association with QTc duration in healthy populations or on their role in adrenergic responses. The duos were composed of 2 relatives harboring the same heterozygous KCNQ1 or KCNH2 mutation: 1 with cardiac events and 1 asymptomatic and untreated. The findings were then validated in 2 independent founder populations totaling 174 symptomatic and 162 asymptomatic patients with LQTS, and a meta-analysis was performed. The KCNQ1 rs2074238 T-allele was significantly associated with a decreased risk of symptoms 0.34 (0.19–0.61; P<0.0002) and with shorter QTc (P<0.0001) in the combined discovery and replication cohorts. Conclusions—We provide evidence that the KCNQ1 rs2074238 polymorphism is an independent risk modifier with the minor T-allele conferring protection against cardiac events in patients with LQTS. This finding is a step toward a novel approach for risk stratification in patients with LQTS.

Gout impacts on function and health-related quality of life beyond associated risk factors and medical conditions: results from the KING observational study of the Italian Society for Rheumatology (SIR)

IntroductionGout is the most prevalent arthritis and significantly impacts on function and quality of life. Given that gout associates with disabling comorbid conditions, it is not clear whether such a complex of diseases accounts for the increased disability or if gout may play a role by itself. This study aims to evaluate the specific influence of gout and disease-related features on functional disability and health-related quality of life (HRQoL) in patients with gout followed in rheumatology clinics.MethodsA random sample of patients was drawn from clinical registries of 30 rheumatology clinics across Italy. Sociodemographic, general health and gout-specific variables were collected. Functional disability and HRQoL were assessed by the health assessment questionnaire (HAQ) and the Physical and Mental Component Summary scores (PCS and MCS) of the Short Form-36 (SF-36). Crude and adjusted ordinal logistic and linear regression models were applied to investigate the specific contribution of different variables on HAQ and SF-36 scores. Results are presented as odds ratio (OR) or mean difference (MD) and 95% confidence intervals.ResultsOut of 446 patients with gout, 90% were males with a mean age of 63.9 years and median disease duration of 3.8 years; the majority of patients were overweight or obese, and with several comorbidities; 21.1% showed at least moderate disability; the PCS score was significantly lower than expected age- and gender-matched samples in the general population, while MCS score was not. After adjusting for potential sociodemographic and general-health confounders, gout-specific variables significantly impacted on HAQ, including polyarticular involvement OR 3.82 (1.63, 8.95), presence of tophi OR 1.92 (1.07, 3.43) and recent attacks OR 2.20 (1.27, 3.81). Consistent results were found for PCS. The impairment of PCS compared to the general population was limited to patients with features of chronic gout. MCS was only affected by recent attacks (MD -2.72 [-4.58, -0.86]) and corticosteroid treatment (-3.39 [-5.30,-1.48]).ConclusionsThe data from the KING study confirm that gout impacts on disability and provide evidence for an independent association of gout and gout-related features with functional outcome and HRQoL. This result supports the need to improve specific treatment in gout.

Estrogen receptor α and APOEɛ4 polymorphisms interact to increase risk for sporadic AD in Italian females

Alzheimers disease (AD) is a progressive neurodegenerative disease that affects both sexes, with a higher prevalence in women. Declining estrogen levels after menopause may render estrogen target neurons in the brain more susceptible to age or disease‐related processes such as AD. To investigate the role of two single nucleotide polymorphisms in the first intron of the ER‐α gene, denominated PvuII and XbaI, and their interaction with the known AD susceptibility gene APOE, we examined 131 patients with sporadic AD and 109 healthy control subjects. In multinomial logistic regression analysis, a significantly increased risk of sporadic AD because of interaction between the ER‐α p allele and APOE ɛ4 allele was observed in women, taking subjects who had neither the p allele nor ɛ4 as reference [odds ratio (OR) 7.24; 95% CI, 2.22–23.60]. For women carrying the ER‐α x allele together with APOE ɛ4, the risk of sporadic AD was similarly elevated (OR 8.33; 95% CI, 1.73–40.06). The data suggest that the p and x alleles of polymorphic ER‐α gene interact synergistically with the APOE ɛ4 allele to increase the risk of AD in women but not in men in this Italian cohort.

Severity Profiles of Substance-Abusing Patients in Italian Community Addiction Facilities: Influence of Psychiatric Concurrent Disorders

Mental health and addiction services have traditionally evolved separately in many European countries, with policy reflecting this. Differences in severity profiles between users of the community addiction services with comorbidities of mental illness and substance misuse and those with substance misuse only were studied using a matched case-control study design, with regard to the main substance (opiates or cocaine) patients were dependent on. Patterns of substance abuse and diagnostic features were evaluated according to the Addiction Severity Index (ASI) and DSM-IV. Mentally ill substance abusers are significantly more likely to have used amphetamines, inhalants and having been polydrug users. They are particularly impaired in medical and family/social relationships ASI composite scores, but less in drug use. Severity profiles and needs of dually diagnosed patients require assessment and treatment skills that should be provided through adequate links with mental health system.

Genome wide identification of new genes and pathways in patients with both autoimmune thyroiditis and type 1 diabetes

Autoimmune thyroid diseases (AITD) and Type 1 diabetes (T1D) frequently occur in the same individual pointing to a strong shared genetic susceptibility. Indeed, the co-occurrence of T1D and AITD in the same individual is classified as a variant of the autoimmune polyglandular syndrome type 3 (designated APS3v). Our aim was to identify new genes and mechanisms causing the co-occurrence of T1D + AITD (APS3v) in the same individual using a genome-wide approach. For our discovery set we analyzed 346 Caucasian APS3v patients and 727 gender and ethnicity matched healthy controls. Genotyping was performed using the Illumina Human660W-Quad.v1. The replication set included 185 APS3v patients and 340 controls. Association analyses were performed using the PLINK program, and pathway analyses were performed using the MAGENTA software. We identified multiple signals within the HLA region and conditioning studies suggested that a few of them contributed independently to the strong association of the HLA locus with APS3v. Outside the HLA region, variants in GPR103, a gene not suggested by previous studies of APS3v, T1D, or AITD, showed genome-wide significance (p < 5 × 10(-8)). In addition, a locus on 1p13 containing the PTPN22 gene showed genome-wide significant associations. Pathway analysis demonstrated that cell cycle, B-cell development, CD40, and CTLA-4 signaling were the major pathways contributing to the pathogenesis of APS3v. These findings suggest that complex mechanisms involving T-cell and B-cell pathways are involved in the strong genetic association between AITD and T1D.

Validation of Plasma Biomarkers in Degenerative Calcific Aortic Stenosis

BACKGROUND Calcific aortic stenosis (CAS) is the most common acquired valvular disorder in industrialized countries. This study investigates the correlation of different known biomarkers for CAS as a first step towards the development of a panel of biomarkers that can be used in prognostic staging. METHODS Venous blood samples were obtained from both patients with CAS scheduled for surgery and healthy individuals. Plasma levels of fetuin-A, NT-proBNP, BNP, homocysteine and osteopontin were measured by enzyme-linked immunosorbent assay (ELISA). CAS was measured by echocardiography and was defined as an aortic valve area of less than 2.0 cm(2). Non-paired t-tests were used for comparison. RESULTS CAS was present in 33 subjects (mean age 75.9 y) and absent in 11 subjects (mean age 55.36 y). Individuals with CAS exhibited higher plasma levels of NT-proBNP (1.33 versus 0.73 pmol/mL, P < 0.05), BNP fragment (1.47 versus 0.34 ng/mL P < 0.05), and osteopontin (60.79 versus 25.42 ng/mL P < 0.05) compared with controls. Fetuin-A levels were lower in individuals with CAS than in healthy controls (0.25 versus 0.34g/L, P < 0.05). Asymmetric dimethylarginine (ADMA) were lower (1.08 versus 1.1 micromol/L, P > 0.05) while homocysteine levels (20.34 +/- 2.14 versus 19.23 +/- 4.19 P > 0.05) were higher in the CAS patients. CONCLUSION This study demonstrates a direct correlation of NT-pro-BNP, BNP, and osteopontin and the presence of CAS, while fetuin A showed an inverse correlation. Plasma ADMA and homocysteine levels were comparable in the CAS patients and healthy individuals. This is the first study in which several biomarkers previously studied independently in patients with CAS have been investigated simultaneously in the same study population.

Are Hsp70 protein expression and genetic polymorphism implicated in multiple sclerosis inflammation

Genetic and environmental factors contribute to disease Multiple Sclerosis (MS) susceptibility, the most prevalent neurological pathology affecting young individuals in Western countries. We focused our attention on HSP70-2, an inducible chaperon induced under stress conditions. Genotype analysis of HSP70-2 (+1267 A/G) polymorphism revealed a significant association between the minor allele G and presence of MS (OR:1.31, 95% CI: 1.02-1.69, P = 0.039). In addition, Hsp70-2 protein content in vitro from PBMC was significantly lower in MS patients with GG genotype compared to AA genotype, indicating an implication of the G allele of HSP70-2 gene polymorphism in the development of MS.