Association between susceptibility to rheumatoid arthritis and <Emphasis Type="Italic">PADI4</Emphasis> polymorphisms: a meta-analysis

The objective of the study was to determine by meta-analysis whether polymorphisms of the gene encoding peptidylarginine deiminase 4 (PADI4) are associated with susceptibility to rheumatoid arthritis (RA). A literature review was conducted to identify data sets that described analyses of genetic association between PADI4 polymorphisms and RA. Data sets were collated and a meta-analysis was performed, with a specific focus on associations within Caucasian and Asian populations. A total of 15,947 RA cases and 22,696 controls that were taken from 28 studies in 24 papers were included in this study. Meta-analysis showed a significant association between allele 2 of the PADI4_94 polymorphism and RA in the overall population (odds ratio [OR]?=?1.155, 95 % confidence interval [CI]?=?1.069–1.249, p?=?2.7?×?10^?5). Stratification by ethnicity revealed an association between PADI4_94 allele 2 and RA in Asians (OR?=?1.273, 95 % CI?=?1.193–1.359, p?<?1.0?×?10^?9), but not in Caucasians (OR?=?1.024, 95 % CI?=?0.973–1.078, p?=?0.358). However, meta-analysis using homozygote contrast showed an association between PADI4_94 allele 2 and RA in both Asians (OR?=?2.311, 95 % CI?=?1.1.858–2.875, p?<?1.0?×?10^?9) and Caucasians (OR?=?1.523, 95 % CI?=?1.157–2.004, p?=?0.008). Meta-analysis also revealed an association between allele 2 of the PADI4_104 polymorphism and RA in both Asians (OR?=?1.547, 95 % CI?=?1.247–1.919, p?=?7.1?×?10^?6) and Caucasians (OR?=?1.096, 95 % CI?=?1.025–1.172, p?=?0.008). Finally, meta-analysis showed an association between allele 2 of the PADI4_92 polymorphism and RA in Asians (OR?=?1.263, 95 % CI?=?1.153–1.384, p?=?5.8?×?10^?8), but not in Caucasians (OR?=?1.123, 95 % CI?=?0.980–1.287, p?=?0.095). Meta-analysis indicated no association between allele 2 of either the PADI4_90 or PADI4_89 polymorphisms and RA in Asians. This meta-analysis revealed that the PADI4_94 and PADI_104 polymorphisms are associated with susceptibility to RA in Asians and Caucasians, and that the PADI4_92 polymorphism is associated with susceptibility to RA in Asians, but not in Caucasians.     

Association Between CD4<Superscript>+</Superscript>, Viral Load,and Pulmonary Function in HIV

Purpose

The antiretroviral therapy era has shifted the epidemiology of HIV-associated diseases, increasing the recognition of non-infectious pulmonary complications secondary to HIV. We aimed to determine the association between CD4⁺, viral load, and pulmonary function in individuals with uncontrolled HIV, and determine how changes in these parameters are associated with pulmonary function longitudinally.

Methods

This is a retrospective observational study of individuals with HIV who underwent pulmonary function testing in an urban medical center between August 1997 and November 2015.

Results

Of the 146 participants (mean age 52 ± 10 years), 49% were Hispanic, 56% were men, and 44% were current smokers. CD4⁺ <200 cells/μl was associated with significant diffusion impairment compared to CD4⁺ ≥200 cells/μl (DL_CO 56 vs. 70%, p = <0.01). VL (viral load) ≥75 copies/ml was associated with significant diffusion impairment compared to VL <75 copies/ml (DL_CO 60 vs. 71%, p = <0.01). No difference in FEV1, FEV1/FVC, or TLC was noted between groups. In univariate analysis, CD4⁺ and VL correlated with DL_CO (r = +0.33; p = <0.01; r = ?0.26; p = <0.01) and no correlation was noted with FEV₁, FEV₁/FVC, or TLC. Current smoking and history of AIDS correlated with DL_CO (r = ?0.20; p = 0.03; r = ?0.20; p = 0.04). After adjusting for smoking and other confounders, VL ≥75 copies/ml correlated with a 11.2 (CI 95% [3.03–19.4], p = <0.01) decrease in DL_CO. In Spearman’s Rank correlation, there was a negative correlation between change in VL and change in DL_CO over time (ρ = ?0.47; p = <0.01).

Conclusion

The presence of viremia in individuals with HIV is independently associated with impaired DL_CO. Suppression of VL may allow for recovery in diffusing capacity over time, though the degree to which this occurs requires further investigation.

     

Distinctive CD8<Superscript>+</Superscript> T cell and MHC class I signatures in polycythemia vera patients

Polycythemia vera (PV) is a myeloproliferative neoplasm characterized by overproduction of red blood cells. We have performed a comprehensive characterization of blood immune cells for expression of naïve and memory receptors as well as β₂m-associated and β₂m-free MHC class I heavy chains, also known as closed and open conformers, respectively, in PV patients and age-matched controls (CTR). We show that the peripheral CD3⁺CD8⁺ T cell pool in PV patients is clearly divided into two discrete populations, a more granular CD3⁺CD8^high T cell population enriched in effector-memory CD45RA⁺ T cells (CD8⁺ TEMRA) when compared to CTR (P?<?0.001), and a less granular CD3⁺CD8^int T cell population that is completely absent in the CTR group (78 vs. 0%, P?<?0.001) and is a mixture of naïve (CD8⁺ T_N) and CD8⁺ TEMRA cells expressing intermediate levels of CD28, i.e., CD3⁺CD8^intCD28^int. While the percentage of CD3⁺CD8^int TN cells correlated positively with the number of erythrocytes, the percentage of CD3⁺CD8^int TEMRA correlated negatively with the number of platelets. Finally, we report that PV patients’ lymphocytes and monocytes display lower levels of closed (W6/32⁺) MHC-I conformers at the cell surface while exhibiting increased amounts of open (HC-10⁺) MHC-I conformers. The implications of this distinctive immune signature are discussed.     

The functional <Emphasis Type="Italic">PTPN22</Emphasis> C1858T polymorphism confers risk for rheumatoid arthritis in patients from Central Mexico

Rheumatoid arthritis (RA) is a complex genetic disease. Human leukocyte antigen (HLA) and non-HLA genes are reportedly associated with an increased risk of RA. The protein tyrosine phosphatase non-receptor 22 gene (PTPN22), which encodes the lymphoid tyrosine phosphatase (LYP) protein, is one of the best examples of a non-HLA gene associated with a risk for RA in several populations. The functional PTPN22 C1858T (R620W) non-synonymous polymorphism is widely associated with an increased risk for RA in Europeans and non-Europeans. The aim of this study was to determine if the PTPN22 C1858T polymorphism confers susceptibility to RA in a sample of patients from Mexico. This study included 364 RA patients and 387 non-related controls from Central Mexico. Genotyping of the PTPN22 C1858T (rs2476601) polymorphism was performed using allelic discrimination assays with TaqMan probes. The functional PTPN22 C1858T polymorphism was associated with an increased risk for RA in our study population. The CC vs CT genotype in RA patients versus healthy controls had an odds ratio (OR) of 4.17 (95 % CI 1.79–9.74, p?=?0.00036), while T allele had an OR of 4.06 (95 % CI 1.75–9.41, p?=?0.00043). PTPN22 is a genetic risk factor for developing RA in the Mexican population.     

Low frequency of CD3<Superscript>+</Superscript>CD4<Superscript>+</Superscript>CD161<Superscript>+</Superscript> T cells correlates with the occurrence of infections in refractory/relapsed multiple myeloma patients receiving lenalidomide plus low-dose dexamethasone treatment

The aim of this study was to explore the predictive implications of the composition of immune cell populations prior to lenalidomide plus high-dose dexamethasone (Len-Dex) initiation for the occurrence of infections. We prospectively examined immune cell populations in peripheral blood taken at baseline of lenalidomide plus low-dose dexamethasone (Len-dex) therapy and reviewed clinical and microbiology records in 90 patients with refractory/relapsed multiple myeloma (RRMM). Risk factors for infection were analyzed using logistic regression. During a median of 11 cycles of Len-dex treatment, 52 (57.8%) patients experienced at least 1 infection episode. Of a total of 92 episodes of infection, 58 (63%) episodes were clinically defined, 29 (31.5%) episodes were microbiologically defined, and 5 (5.4%) episodes were fever of unknown origin. Severe episodes were more frequently observed during the first 3 cycles. After adjusting for risk factors for infection based on univariate analyses, multivariate analyses showed that lower Hb (<?10 g/dL) was a clinically independent factor associated with occurrence of infections. Lower frequency (P?=?0.044) and absolute count (P?=?0.014) of circulating CD3⁺CD4⁺CD161⁺ cells prior to Len-dex treatment were also associated with the occurrence of infection, especially during the first 3 cycles of Len-dex therapy. In addition to several clinical predictive factors, we found that CD3⁺CD4⁺CD161⁺ cells may provide additional information for predicting the occurrence of infection in the early period of Len-dex therapy.     

Characterization and CRISPR-based genotyping of clinical <Emphasis Type="Italic">trh</Emphasis>-positive <Emphasis Type="Italic">Vibrio parahaemolyticus</Emphasis>

Background

Vibrio parahaemolyticus is a causative agent of gastroenteritis. Most of the clinical isolates carry either tdh and/or trh genes which are considered as the major virulence genes of this pathogen. In this study, the clinical isolates of V. parahaemolyticus carrying trh gene (n?=?73) obtained from 1886 to 2012 from various countries were investigated for the urease production, haemolytic activity, and biofilm formation. In addition, the potential of clustered regularly interspaced short palindromic repeats (CRISPR)-based genotyping among these isolates was investigated.

Results

In this study, no significant differences were observed in the urease production between tdh⁺ trh1⁺ and tdh⁺ trh2⁺ isolates (p?=?0.063) and between the tdh^? trh1⁺ and tdh^? trh2⁺ isolates (p?=?0.788). The isolates carrying only the trh gene showed variation in their haemolytic activity. The ratio of urease production and haemolytic activity between the trh1⁺ and trh2⁺ isolates and biofilm formation of trh⁺ V. parahaemolyticus isolates were not significantly different. Sixteen of thirty-four tested isolates (47.0%) of trh⁺ V. parahaemolyticus were positive for CRISPR detection. The discriminatory power index (DI) of CRISPR-virulence typing was higher than the DI obtained by CRISPR typing alone.

Conclusion

The tdh and trh genes were not involved in urease production in the trh⁺ V. parahaemolyticus, and variation of haemolytic activity detected in V. parahaemolyticus carrying only the trh gene might be correlated to the sequence variation within trh1 and trh2 genes. Additionally, biofilm production of V. parahaemolyticus was not associated with harboring of virulence genes. For genotyping, CRISPR sequences combined with virulence genes can be used as genetic markers to differentiate trh⁺ V. parahaemolyticus strains.

     

Characterization of copy number variants for <Emphasis Type="Italic">CCL3L1</Emphasis> gene in rheumatoid arthritis for French trio families and Tunisian cases and controls

Analyses of copy number variants (CNVs) for candidate genes in complex diseases are currently a promising research field. CNVs of C–C chemokine ligand 3-like 1 (CCL3L1) gene are candidate genomic factors in rheumatoid arthritis (RA). We investigated CCL3L1 CNVs association with a case-control study in Tunisians and a transmission analysis in French trio families. Relative copy number (rCN) of CCL3L1 gene was quantified by droplet digital PCR (ddPCR) in 100 French trio families (RA patients and their two parents) and in 166 RA cases and 102 healthy controls from Tunisia. We calculated odds ratio (OR) to investigate association risk for CCL3L1 CNVs in RA. rCN identified varied from 0 to 4 in the French population and from 0 to 7 in the Tunisian population. A significant difference was observed in the distribution of these rCNs between the two populations (p?=?2.34?×?10^?10), as when rCN from French and Tunisian RA patients were compared (p?=?2.83?×?10^?5). CNVs transmission in French RA trios allowed the characterization of genotypes with the presence of tandem duplication and triplication on the same chromosome. RA association tests highlighted a protective effect of rCN?=?5 for CCL3L1 gene in the Tunisian population (OR?=?0.056; CI 95 % [0.01–0.46]). Characterization of CCL3L1 CNVs with ddPCR methodology highlighted specific CN genotypes in a French family sample. A copy number polymorphism of a RA candidate gene was quantified, and its significant association with RA was revealed in a Tunisian sample.     

Association between urinary sodium and potassium excretion and blood pressure and inflammation in patients with rheumatoid arthritis

Hypertension is highly prevalent in patients with rheumatoid arthritis (RA). In other populations, high sodium (Na⁺) and low potassium (K⁺) intake are associated with an increased risk of hypertension, and in animal models, a high salt intake exacerbated arthritis. Patients with RA have many comorbidities associated with salt sensitivity, but their salt intake and its relationship to blood pressure and inflammation is unknown. Using the Kawasaki formula, Na⁺ and K⁺ urinary excretion (reflecting intake) was estimated in 166 patients with RA and 92 controls, frequency matched for age, sex, and race. Inflammatory markers and disease activity were measured in RA patients. We tested the associations between blood pressure and Na⁺ and K⁺ excretion. Estimated 24-h Na⁺ excretion was similarly high in both RA (median [IQR] 5.1 g, [3.9–6.6 g]) and controls (4.9 g, [4.0–6.5 g]), p?=?0.9, despite higher rates of hypertension in RA (54 vs. 39%, p?=?0.03). The Na⁺:K⁺ excretion ratio was significantly higher in RA (2.0 [1.6–2.4]) vs. 1.7 [1.5–2.1]), p?=?0.02] compared to controls. In RA, a lower K⁺ excretion was inversely correlated with diastolic blood pressure (adjusted β?=???1.79, p?=?0.04). There was no significant association between Na⁺ or K⁺ excretion and inflammatory markers. Despite a similar Na⁺ excretion, patients with RA had higher rates of hypertension than controls, a finding compatible with increased salt sensitivity. Patients with RA had a lower Na⁺:K⁺ excretion ratio than controls, and lower K⁺ excretion was associated with higher diastolic blood pressure in RA.     

A proinflammatory CD4<Superscript>+</Superscript> T cell phenotype in gestational diabetes mellitus

Aims/hypothesis

Numerous adaptations of the maternal immune system are necessary during pregnancy to maintain immunological tolerance to the semi-allogeneic fetus. Several complications of pregnancy have been associated with dysregulation of these adaptive mechanisms. While gestational diabetes mellitus (GDM) has been associated with upregulation of circulating inflammatory factors linked to innate immunity, polarisation of the adaptive immune system has not been extensively characterised in this condition. We aimed to characterise pro- and anti-inflammatory CD4⁺ (T helper [Th]) T cell subsets in women with GDM vs women without GDM (of similar BMI), during and after pregnancy, and examine the relationship between CD4⁺ subsets and severity of GDM.

Methods

This is a prospective longitudinal case–control study of 55 women with GDM (cases) and 65 women without GDM (controls) at a tertiary maternity hospital. Quantification of proinflammatory (Th17, Th17.1, Th1) and anti-inflammatory (regulatory T cell [Treg]) CD4⁺ T cell subsets was performed on peripheral blood at 37 weeks gestation and 7 weeks postpartum, and correlated with clinical characteristics and measures of blood glucose.

Results

Women with GDM had a significantly greater percentage of Th17 (median 2.49% [interquartile range 1.62–4.60] vs 1.85% [1.13–2.98], p?=?0.012) and Th17.1 (3.06% [1.30–4.33] vs 1.55% [0.65–3.13], p?=?0.006) cells compared with the control group of women without GDM. Women with GDM also had higher proinflammatory cell ratios (Th17:Treg, Th17.1:Treg and Th1:Treg) in pregnancy compared with the control group of women without GDM. In the control group, there was a statistically significant independent association between 1 h glucose levels in the GTT and Th17 cell percentages, and also between 2 h glucose levels and percentage of Th17 cells. The percentage of Th17 cells and the Th17:Treg ratio declined significantly after delivery in women with GDM, whereas this was not the case with the control group of women. Nevertheless, a milder inflammatory phenotype persisted after delivery (higher Th17:Treg ratio) in women with GDM vs women without.

Conclusions/interpretation

Dysregulation of adaptive immunity supports a novel paradigm of GDM that extends beyond hyperglycaemia and altered innate immunity.

     

Donor-recipient killer immunoglobulin like receptor (KIR) genotype matching has a protective effect on chronic graft versus host disease and relapse incidence following HLA-identical sibling hematopoietic stem cell transplantation

Impact of donor-recipient killer immunoglobulin-like receptor (KIR) gene-gene matching on transplant outcomes is still inconclusive. Recent data suggest that killer cell immunoglobulin-like receptor (KIR) regulated natural killer cell (NK cell) activity may contribute to graft versus leukemia (GvL) effects and graft versus host disease (GvHD) after allogeneic hematopoietic stem cell transplantation (allo-HSCT). This case-control study aims to evaluate the effects of both aKIR and iKIR donor-recipient genotype matching on the outcomes of T cell replete HLA-identical sibling allo-HSCTs in a homogenous young patient population with myeloid leukemias. Five transplant outcomes including relapse rate (RR), disease-free survival (DFS), overall survival (OS), cumulative incidences of acute GvHD (aGvHD), and chronic GvHD (cGvHD) are investigated. Out of 96 HLA-identical sibling donor-recipient pairs, 34 were matched for activating KIR (aKIR), 38 for inhibitory KIR (iKIR), and 20 for both aKIR and iKIR. Fourty-four pairs were mismatched for both iKIR and aKIR. In univariate analysis, aKIR-matching resulted with a decrease in relapse rate (RR) (hazard ratio [HR]: 0.4; p?=?0.04) and an increase in disease-free survival (DFS) (HR: 0.5; p?=?0.03). In addition, cGvHD ocurred less frequently in the aKIR-matched (odds ratio [OR]: 0.4; p?=?0.04) or iKIR-matched (OR: 0.3; p?=?0.009) cohorts. Matching for both aKIR and iKIR was also associated with a decrease in cGvHD incidence (OR: 0.3; p?=?0.02). iKIR-matching had no effects on RR, OS, or DFS. Analysis of donor haplotype effects showed haplotype-BB to have a tendency towards reduced relapse rate (HR: 0.4; p?=?0.08) and better OS (HR: 0.4; p?=?0.04); haplotype-Bx to increase the incidence of cGvHD (OR: 4.1; p?=?0.03). In multivariate analysis, DFS advantage remained significant for aKIR-matching (HR: 0.5; p?=?0.04); cGvHD incidence was reduced in the presence of iKIR-match (OR: 0.3; p?=?0.02) and increased in the presence of haplotype-AB and -BB donors (OR: 7.9; p?=?0.02; OR: 5.1; p?=?0.03, respectively). In an attempt to investigate the pathogenesis underlying KIR-matching, we searched for residual NK/T cells on day 0 peripheral blood samples of six additional recipients and noted the presence of CD3⁺ (7.0–91.4?×?10⁶/L) and CD56⁺57⁺ (0.8–12.7?×?10⁶/L) cells. In conclusion, conditioning regimen surviving recipient NK/T cells potentially influenced by KIR-matching may contribute to GvL/GvH reactions.     

Evaluation of work disability in Japanese patients with rheumatoid arthritis: from the TOMORROW study

To evaluate work disability and associated factors in patients with rheumatoid arthritis (RA) who participated in the TOMORROW study, a 10-year cohort study in Japan. Subjects in this cross-sectional analysis comprised 191 RA patients and 191 age- and sex-matched non-RA individuals. Work-related outcomes were measured using the Work Productivity and Activity Impairment questionnaire by employment status (full-time worker (FTW), employed ≥ 35 h/week; part-time worker (PTW), < 35 h/week; home worker (HW), non-employed). In addition, we assessed the EuroQol-5 Dimensions (EQ-5D) and Health Assessment Questionnaire (HAQ) to evaluate quality of life and activities of daily living. No significant differences were evident between groups in percentages of participants in each employment status (p =?0.11), percentages of absenteeism (FTW, p?=?1.00; PTW, p?=?0.29), presenteeism (FTW, p?=?0.23; PTW, p?=?0.54), overall work impairment (FTW, p?=?0.23; PTW, p?=?0.73), or percentage of activity impairment (AI) (FTW, p?=?0.62; PTW, p?=?0.60). In the HW group, percentage of AI was higher in RA patients than that in non-RA patients (p?<?0.01). Among RA patients, HW showed lower EQ-5D and higher HAQ than FTW or PTW (p?<?0.001 each). Higher disease activity was observed in HW than FTW (p <?0.01). In terms of the effect of biological disease-modifying anti-rheumatic drugs, no significant differences in work-related outcomes, health status, or daily activity were evident between users and non-users. No significant differences in employment status or work impairment were seen between RA and non-RA groups among paid workers. HW with RA showed more impaired daily activity and higher disease activity compared to working RA patients. Trial registration: University Hospital Medical Information Network Clinical Trials Registry: UMIN000003876. Registered 1 Jun 2010.     

Targeted deletion of <Emphasis Type="Italic">Traf2</Emphasis> allows immunosuppression-free islet allograft survival in mice

Aims/hypothesis

Administration of anti-CD40 ligand (CD40L) antibodies has been reported to allow long-term islet allograft survival in non-human primates without the need for exogenous immunosuppression. However, the use of anti-CD40L antibodies was associated with thromboembolic complications. Targeting downstream intracellular components shared between CD40 and other TNF family co-stimulatory molecules could bypass these complications. TNF receptor associated factor 2 (TRAF2) integrates multiple TNF receptor family signalling pathways that are critical for T cell activation and may be a central node of alloimmune responses.

Methods

T cell-specific Traf2-deficient mice (Traf2TKO) were generated to define the role of TRAF2 in CD4⁺ T cell effector responses that mediate islet allograft rejection in vivo. In vitro allograft responses were tested using mixed lymphocyte reactions and analysis of IFN-γ and granzyme B effector molecule expression. T cell function was assessed using anti-CD3/CD28-mediated proliferation and T cell polarisation studies.

Results

Traf2TKO mice exhibited permanent survival of full MHC-mismatched pancreatic islet allografts without exogenous immunosuppression. Traf2TKO CD4⁺ T cells exhibited reduced proliferation, activation and acquisition of effector function following T cell receptor stimulation; however, both Traf2TKO CD4⁺ and CD8⁺ T cells exhibited impaired alloantigen-mediated proliferation and acquisition of effector function. In polarisation studies, Traf2TKO CD4⁺ T cells preferentially converted to a T helper (Th)2 phenotype, but exhibited impaired Th17 differentiation. Without TRAF2, thymocytes exhibited dysregulated TNF-mediated induction of c-Jun N-terminal kinase (JNK) and canonical NFκB pathways. Critically, targeting TRAF2 in T cells did not impair the acute phase of CD8-dependent viral immunity. These data highlight a specific requirement for a TRAF2–NFκB and TRAF2–JNK signalling cascade in T cell activation and effector function in rejecting islet allografts.

Conclusion/interpretation

Targeting TRAF2 may be useful as a therapeutic approach for immunosuppression-free islet allograft survival that avoids the thromboembolic complications associated with the use of anti-CD40L antibodies.

     

Non-driver mutations in patients with <Emphasis Type="Italic">JAK2</Emphasis>V617F-mutated polycythemia vera or essential thrombocythemia with long-term molecular follow-up

JAK2V617F monitoring and NGS of non-driver genes was performed in 100 patients with polycythemia vera (PV) or essential thrombocythemia (ET) with long molecular follow-up. Patients who did not progress to myelofibrosis (MF) or acute myeloid leukemia (AML) after more than 10 years (n?=?50) showed a low frequency of mutations at first sample (18%) and an incidence rate of 1.7 new mutations?×?100 person-years. Mutations were detected at first sample in 83% of PV/ET patients who later progressed to AML (n?=?12) with these patients having a rate of 25.6 mutations?×?100 person-years. Presence of mutations at diagnosis was the unique risk factor for acquiring a new genetic event (HR 2.7, 95% CI 1.1–6.8, p?=?0.03) after correction for age, PV diagnosis, and total duration of hydroxyurea (HU) exposure. Patients with additional mutation at first sample showed a higher probability of developing cytopenia under HU therapy and a higher risk of AML (HR 12.2, 95% CI 2.6–57.1, p?=?0.001) with mutations in ASXL1 (p?<?0.0001), TP53 (p?=?0.01), SRSF2 (p?<?0.0001), IDH1/2 (p?<?0.0001), and RUNX1 (p?<?0.0001) being associated with a higher probability of AML. Myelofibrotic transformation was more frequent in patients with additional mutations, especially in SF3B1 (p?=?0.02) and IDH1/2 (p?<?0.0001) although a persistently high or a progressive increase of the JAK2V617F allele burden while receiving cytoreduction was the strongest predictor of MF transformation (HR 10.8, 95% CI 2.4–49.1, p?=?0.002). In conclusion, NGS may be useful to identify a minority of PV and ET patients with high genetic instability and increased risk of AML transformation.     

Arterial stiffness is associated with left ventricular dysfunction in patients with rheumatoid arthritis

Arterial stiffness (AS) has a detrimental effect on cardiovascular system particularly on left ventricle (LV). The aim of the study was to evaluate the impact of AS on LV functions in patients with rheumatoid arthritis (RA). Forty patients with RA and 25 age-sex matched control subjects (mean age 48.5?±?6.3 vs. 45.1?±?6.9 years, respectively, p?=?0.06) were enrolled in study. AS was assessed by carotid-femoral pulse wave velocity (CF-PWV) and heart rate corrected augmentation index (AIx@75) measured by applanation tonometry (SphygmoCor). LV function was evaluated using tissue Doppler-derived myocardial performance index (MPI) from lateral mitral annulus. CF-PWV (28.3?±?10.3 vs. 21.8?±?9.3 m/s, p?=?0.03), AIx@75 (10.2?±?2.3 vs. 9.2?±?1, %, p?=?0.01) and MPI (0.46?±?0.12 vs. 0.36?±?0.1, p?<?0.001) were significantly higher in patients with RA than in controls. LV MPI was found to be significantly positive correlated with CF-PWV, AIx@75, and ESR (r?=?0.360, p?=?0.005; r?=?0.334, p?=?0.009; r?=?0.293, p?=?0.023, respectively). Arterial stiffness parameters including CF-PWV and AIx@75 are associated with subclinical left ventricular dysfunction in patients with RA.     

<Emphasis Type="Italic">Fas/FasL,Bcl2</Emphasis> and <Emphasis Type="Italic">Caspase</Emphasis>-<Emphasis Type="Italic">8</Emphasis> gene polymorphisms in Chinese patients with rheumatoid arthritis

Apoptosis signals are necessary for maintaining homeostasis and an adequate immune response. Dysregulation of apoptosis-related genes in the immune system has an important impact on autoimmune diseases such as rheumatoid arthritis (RA). Thus, we investigated the association between Fas rs2234767 G/A, FasL rs763110 C/T, Bcl2 rs12454712 T/C, Bcl2 rs17757541 C/G, and Caspase-8 rs1035142 G/T polymorphisms and RA susceptibility in a Chinese population. These five single-nucleotide polymorphisms (SNPs) were studied in a Chinese population consisting of 615 patients with RA and 839 controls. Genotyping was performed using a custom-by-design 48-Plex SNP scan TM kit. Furthermore, we undertook a meta-analysis between FasL rs763110 C/T and RA. This study indicated that Fas rs2234767 and Bcl2 rs17757541 polymorphisms were risk factors for RA. No association was observed between FasL rs763110 C/T, Bcl2 rs12454712 T/C, and Caspase-8 rs1035142 G/T polymorphisms and RA in this study. The results of this meta-analysis suggested no significant association between FasL rs763110 C/T and RA. However, stratification analysis of this meta-analysis indicated that FasL rs763110 C/T increased the risk of Caucasian RA patients. In conclusion, this study demonstrated that Fas rs2234767 G/A and Bcl2 rs17757541 T/C polymorphisms might be associated with an increased risk of RA. This meta-analysis revealed that FasL rs763110 C/T was associated with an increased risk of Caucasian RA patients.     

<Emphasis Type="Italic">Gcg</Emphasis><Superscript><Emphasis Type="Italic">CreERT2</Emphasis></Superscript> knockin mice as a tool for genetic manipulation in pancreatic alpha cells

Aims/hypothesis

The Cre/loxP system, which enables tissue-specific manipulation of genes, is widely used in mice for diabetes research. Our aim was to develop a new Cre-driver mouse line for the specific and efficient manipulation of genes in pancreatic alpha cells.

Methods

A Gcg ^CreERT2 knockin mouse, which expresses a tamoxifen-inducible form of Cre from the endogenous preproglucagon (Gcg) gene locus, was generated by homologous recombination. The new Gcg ^CreERT2 mouse line was crossed to the Rosa26 ^tdTomato (R26 ^tdTomato ) Cre reporter mouse line in order to evaluate the tissue specificity, efficiency and tamoxifen dependency of Gcg ^CreERT2 -mediated recombination. Cell types of pancreatic islets were identified using immunohistochemistry. Biochemical and physiological data, including blood glucose levels, plasma glucagon and glucagon-like peptide (GLP)-1 levels, and pancreatic glucagon content, were collected and used to assess the overall effect of Gcg gene targeting on Gcg ^CreERT2/w heterozygous mice.

Results

Tamoxifen-treated Gcg ^CreERT2/w ;R26 ^tdTomato/w mice displayed Cre reporter activity, i.e. expression of tdTomato red fluorescent protein (RFP) in all known cells that produce proglucagon-derived peptides. In the adult pancreas, RFP was detected in 94–97% of alpha cells, whereas it was detected in a negligible (~ 0.2%) proportion of beta cells. While more than 98% of cells labelled with tamoxifen-induced RFP were glucagon-positive cells, 14–25% of pancreatic polypeptide (PP)-positive cells were also positive for RFP, indicating the presence of glucagon/PP bihormonal cell population. Tamoxifen-independent expression of RFP occurred in approximately 6% of alpha cells. In contrast to alpha cells and GLP-1-producing neurons, in which RFP expression persisted for at least 5 months after tamoxifen administration (presumably due to rare neogenesis in these cell types in adulthood), nearly half of RFP-positive intestinal L cells were replaced with RFP-negative L cells over the first 2 weeks after tamoxifen administration. Heterozygous Gcg ^CreERT2/w mice showed reduced Gcg mRNA levels in islets, but maintained normal levels of pancreatic and plasma glucagon. The mice did not exhibit any detectable baseline physiological abnormalities, at least in young adulthood.

Conclusions/interpretation

The newly developed Gcg ^CreERT2 knockin mouse shows faithful expression of CreER^T2 in pancreatic alpha cells, intestinal L cells and GLP-1-producing neurons. This mouse line will be particularly useful for manipulating genes in alpha cells, due to highly specific and efficient CreER^T2-mediated recombination in this cell type in the pancreas.

     

Cytotoxic isolates of <Emphasis Type="Italic">Helicobacter pylori</Emphasis> from Peptic Ulcer Diseases decrease K<Superscript>+</Superscript>-dependent ATPase Activity in HeLa cells

Background

Helicobacter pylori is a Gram negative bacterium that plays a central role in the etiology of chronic gastritis and peptic ulcer diseases. However, not all H. pylori positive cases develop advanced disease. This discriminatory behavior has been attributed to the difference in virulence of the bacteria. Among all virulence factors, cytotoxin released by H. pylori is the most important factor. In this work, we studied variation in H. pylori isolates from Indian dyspeptic patients on the basis of cytotoxin production and associated changes in K⁺-dependent ATPase (one of its targets) enzyme activity in HeLa cells.

Methods

The patients were retrospectively grouped on the basis of endoscopic and histopathological observation as having gastritis or peptic ulcer. The HeLa cells were incubated with the broth culture filtrates (BCFs) of H. pylori isolates from patients of both groups and observed for the cytopathic effects: morphological changes and viability. In addition, the K⁺-dependent ATPase activity was measured in HeLa cells extracts.

Results

The cytotoxin production was observed in 3/7 (gastritis) and 4/4 (peptic ulcer) H. pylori isolates. The BCFs of cytotoxin producing H. pylori strains reduced the ATPase activity of HeLa cells to 40% of that measured with non-cytotoxin producing H. pylori strains (1.33 μmole Pi/mg protein and 3.36 μmole Pi/mg protein, respectively, p < 0.05). The decreased activity of ATPase enzyme or the release of cytotoxin also correlated with the increased pathogenicity indices of the patients.

Conclusions

Our results suggest that the isolation of cytotoxic H. pylori is more common in severe form of acid peptic diseases (peptic ulcer) than in gastritis patients from India. Also the cytotoxin released by H. pylori impairs the ion-transporting ATPase and is a measure of cytotoxicity.

     

Disease severity impacts the relationship of apelin with arterial function in patients with rheumatoid arthritis

Apelin can improve arterial function by enhancing the expression of endothelial nitric oxide synthase but this effect depends markedly on endothelial integrity. We hypothesized that inflammation influences the potential impact of apelin on arterial function in rheumatoid arthritis (RA). We assessed the associations of apelin concentrations with arterial stiffness (pulse wave velocity), wave reflection (augmentation index, reflected wave pressure, and reflection magnitude), and pressure pulsatility (central systolic pressure (CSP), central pulse pressure (CPP), peripheral pulse pressure (PPP), pulse pressure amplification (PPamp), and forward wave pressure (Pf)) among 170 RA patients without cardiovascular disease. In multivariable regression models, apelin concentrations were not independently associated with arterial function measures (p?≥?0.15) in all patients. Inflammation markers were not consistently associated with apelin levels but joint deformity counts, Disease Activity Score in 28 joints (DAS28), and erythrocyte sedimentation rate (ESR) impacted apelin-pressure pulsatility relations (interaction p?≤?0.05). In stratified analysis, apelin was associated with CSP (partial r?=???0.33, p?=?0.01), CPP (partial r?=???0.26, p?=?0.04), PPamp (partial r?=?0.27, p?=?0.03), and Pf (partial r?=???0.33, p?=?0.01) in patients without but not with joint deformities; apelin was related to CSP (partial r?=???0.24, p?=?0.05) in those with a DAS28 joint <?2.8 (median value) (partial r?=???0.24, p?=?0.05) but not ≥?2.8, and to CSP (partial r?=???0.36, p?=?0.003) in those with an erythrocyte sedimentation rate <?13 mm/h (median value) but not ≥?13 mm/h. Apelin is associated with reduced pressure pulsatility in RA patients without but not with a high inflammatory burden. A loss of apelin protective effects on arterial function may contribute to the link between RA severity and cardiovascular risk.     

<Emphasis Type="Italic">MHC2TA</Emphasis> and <Emphasis Type="Italic">FCRL3</Emphasis> genes are not associated with rheumatoid arthritis in Mexican patients

Rheumatoid arthritis (RA) is a multifactorial disease. A combination of genetic and environmental risk factors contributes to its etiology. Several genes have been reported to be associated with susceptibility to the development of RA. The MHC2TA and FCRL3 genes have been associated previously with RA in Swedish and Japanese populations, respectively. In two recent reports, we show an association between FCRL3 and juvenile rheumatoid arthritis (JRA), and MHC2TA and acute coronary syndrome (ACS) in Mexican population. We assessed the association between three single nucleotide polymorphisms (SNPs) of the MHC2TA (?168G/A; rs3087456, and +16G/C; rs4774) and FCRL3 (?169T/C; rs7528684) genes and rheumatoid arthritis in Mexican population through a genotyping method using allelic discrimination assays with TaqMan probes. Our case–control study included 249 patients with RA and 314 controls. We found no evidence of an association between the MHC2TA ?168G/A and +1614G/C or FCRL3 ?169T/C polymorphisms and RA in this Mexican population. In this cohort of Mexican patients with RA, we observed no association between the MHC2TA or FCRL3 genes and this autoimmune disease.