Intra-hospital variation of gut microbiota product, trimethylamine N-oxide (TMAO) predicts future major adverse cardiovascular events after myocardial infarction

BACKGROUND AND AIMS

Trimethylamine N-oxide (TMAO) has been associated with atherosclerosis and poor outcome. We evaluated the prognostic impact of intra-hospital TMAO variation on patient outcome.

METHODS AND RESULTS

Blood samples from 149 patients with acute myocardial infarction (AMI) were taken on admission and discharge. Plasma TMAO was determined by HPLC-MS. The endpoint was a composite three-point MACE (major adverse cardiovascular events) including all-cause mortality, re-infarction or the heart failure (HF) development. Median TMAO concentration on admission was significantly higher than on discharge, (respectively, 7.81 [3.47 - 19.98] vs 3.45 [2.3 - 4.78] μM,p<0.001). After estimating the 3.45 μM TMAO cut-off with the analysis of continuous hazard ratio, we divided our cohort into two groups. The first group included 75 (50.3%) patients whose TMAO levels remained below or decreased under cut-off (low-low/high-low; LL/HL), while the second group included 74 (49.7%) patients whose TMAO levels remained high or increased above the cut-off during hospitalisation (high-high/low-high; HH/LH). During the median 30-month follow-up, 21.5% patients experienced the composite endpoint. At Kaplan-Meier analysis, a trend of increasing MACE risk was observed in patients in the HH/LH group (p=0.05). At multivariable Cox analysis, patients from HH/LH group had more than two times higher risk of MACE during the follow-up than LL/HL group (HR=2.15 [95% CI, 1.03 - 4.5], p=0.04). Other independent predictors of MACE were older age and worse left ventricular systolic function.

CONCLUSIONS

In patients with AMI, permanently high or increasing TMAO levels during hospitalisation are associated with a higher risk of MACE during long-term follow-up.

Circulating PV-1 as a marker of celiac disease-associated liver injury

Aim: To investigate the role of endothelial PV-1 in patients with untreated celiac disease (CD)-associated liver injury. Materials & methods: PV-1 and PV-1 mRNA were measured in intestinal biopsies from untreated CD patients with elevated or normal alanine transaminase levels, controls, patients with inflammatory bowel disease and patients with toxic liver injury. Circulating PV-1 levels were also evaluated. Results: Circulating PV-1 levels were significantly increased in the serum of patients with CD-associated liver injury and reverted to normal following a gluten-free diet. Mucosal PV-1 and PV-1 mRNA were no different in patients with CD-associated liver injury. Conclusion: Serum but not mucosal PV-1 represents a marker of gluten-dependent liver injury and response to a gluten-free diet in patients with untreated CD.

Prognostic implications of previously known or newly diagnosed diabetes and hypovitaminosis D in patients with myocardial infarction

Background

Vitamin D deficiency and diabetes mellitus are frequent among patients with acute myocardial infarction. Independently, both were associated with a worse prognosis after myocardial infarction (MI). However, it is unclear whether the risk of worse outcome, associated with diabetes mellitus, may be accentuated in presence of hypovitaminosis D.

Purpose

We assessed if previously known or newly diagnosed diabetes is associated with worse outcome (major cardiovascular events) in combination with hypovitaminosis D in patients with acute MI.

Methods and results

Were enrolled 1004 patients with acute MI; 64.7% of them, had hypovitaminosis D and 37% were diabetic.

We grouped our population by diabetic status: previously known diabetes (diagnosis of diabetes before MI, n=330; 32.9%); newly diagnosed diabetes (during hospitalization for MI, but no known diabetes at presentation, n=47; 4.7%); or no diabetes (n=627; 62.5%).

Hypovitaminosis D was more frequent among patients with previously known (70.2%) and newly diagnosed diabetes (73.3%), when compared to non diabetic patients (61.2%).

During median follow-up of 15.6 months, patients with previously known and newly diagnosed diabetes had increased risks of major cardiovascular events (HR 1.72; 95% CI, 1.26 to 2.36. The risk of major events during the follow-up among diabetic patients, was further increased in presence of hypovitaminosis D (Figure 1).

Conclusions

The presence of both, previously known or newly diagnosed diabetes and hypovitaminosis D, in patients with MI is synergistically associated with a worse outcome.

Funding Acknowledgement

Type of funding source: None

COVID-19 and renin-angiotensin system inhibition: role of angiotensin converting enzyme 2 (ACE2) - Is there any scientific evidence for controversy?

Renin-angiotensin system (RAS) blockers are extensively used worldwide to treat many cardiovascular disorders, where they are effective in reducing both mortality and morbidity. These drugs are known to induce an increased expression of angiotensin-converting enzyme 2 (ACE2). ACE2 acts as receptor for the novel SARS coronavirus-2 (SARS-CoV-2) which raising the important issue of possible detrimental effects that RAS blockers could exert on the natural history and pathogenesis of the coronavirus disease-19 (COVID-19) and associated excessive inflammation, myocarditis and cardiac arrhythmias. We review the current knowledge on the interaction between SARS-CoV-2 infection and RAS blockers and suggest a scientific rationale for continuing RAS blockers therapy in patients with COVID-19 infection.

Diabetes Mellitus and Vitamin D Deficiency:Comparable Effect on Survival and a DeadlyAssociation after a Myocardial Infarction

Survivors after a myocardial infarction (MI), especially those with diabetes mellitus (DM), remain at high risk of further events. Identifying and treating factors that may influence survival may open new therapeutic strategies. We assessed the impact on prognosis of DM and hypovitaminosis D (hypovitD), alone or combined. In this prospective, observational study, 1081 patients were enrolled surviving an MI and divided into four groups according to their diabetic and VitD status. The primary end-point was composite of all-cause mortality, angina/MI and heart failure (HF). Secondary outcomes were mortality, HF and angina/MI. During a follow-up of 26.1 months (IQR 6.6–64.5), 391 subjects experienced the primary end-point. Patients with DM or hypovitD had similar rate of the composite end-point. Patients with only hypovitD or DM did not differ regarding components of composite end-point (angina p = 0.97, HF p = 0.29, mortality p = 0.62). DM and VitD deficiency had similarly adjusted risks for primary end-point (HR 1.3, 95%CI 1.05–1.61; HR 1.3, 95% CI 1.04–1.64). The adjusted HR for primary composite end-point for patients with hypovitD and DM was 1.69 (95%CI 1.25–2.29, p = 0.001) in comparison to patients with neither hypoD nor DM. In conclusion, DM and hypovitD, individually and synergistically, are associated with a worse outcome after MI.

Persistent viremia and urine shedding of tick-borne encephalitis virus in an infected immunosuppressed patient from a new epidemic cluster in North-Eastern Italy

A persistent tick-borne encephalitis virus infection in an immune-suppressed patient is presented. Such an unusual clinical case offers the unique chance of detecting persistent viremia associated to the erythrocyte fraction and shedding of the virus in the urine for more than six weeks. The infection occurred in a new area of the Friuli Venezia-Giulia region (North Eastern Italy) where two additional cases are also being reported.

Mass screening for coeliac disease using antihuman transglutaminase antibody assay

AIMS

To determine coeliac disease prevalence by an anti-transglutaminase antibody assay in a large paediatric population; to evaluate acceptance of the screening programme, dietary compliance, and long term health effects.

METHODS

Cross-sectional survey of 3188 schoolchildren (aged 6-12) and prospective follow up of diagnosed cases. Main outcome measures were: prevalence of coeliac disease defined by intestinal biopsy or positivity to both human tissue transglutaminase and anti-endomysium antibodies in HLA DQ2-8 positive subjects; percentage of children whose families accepted screening; dietary compliance as defined by negativity for anti-transglutaminase antibodies; and presence of clinical or laboratory abnormalities at 24 month follow up.

RESULTS

The families of 3188/3665 children gave their consent (87%). Thirty biopsy proven coeliacs were identified (prevalence 1:106). Three other children testing positive for both coeliac related autoantibodies and HLA DQ2-8 but refusing biopsy were considered as having coeliac disease (prevalence 1:96). Of 33 cases, 12 had coeliac related symptoms. The 30 biopsy proven coeliacs followed a gluten-free diet. Of 28 subjects completing 18-24 months follow up, 20 (71.4%) were negative for anti-transglutaminase antibodies, while eight were slightly positive; symptoms resolved in all 12 symptomatic children.

CONCLUSIONS

Prevalence of coeliac disease is high in Italian schoolchildren. Two thirds of cases were asymptomatic. Acceptance of the programme was good, as was dietary compliance. Given the high prevalence and possible complications of untreated coeliac disease, the availability of a valid screening method, and evidence of willingness to comply with dietary treatment population mass screening deserves careful consideration.

Allelism of MCKD, FJHN and GCKD caused by impairment of uromodulin export dynamics

The disease complex medullary cystic disease/familial juvenile hyperuricemic nephropathy (MCKD/FJHN) is characterized by alteration of urinary concentrating ability, frequent hyperuricemia, tubulo-interstitial fibrosis, cysts at the cortico-medullary junction and renal failure. MCKD/FJHN is caused by mutations of the gene encoding uromodulin, the most abundant protein in urine. Here, we describe new missense mutations in three families with MCKD/FJHN and demonstrate allelism with a glomerulocystic kidney disease (GCKD) variant, showing association of cyst dilatation and collapse of glomeruli with some clinical features similar to MCKD/FJHN as hyperuricemia and impairment of urine concentrating ability. Furthermore, we provide the first functional characterization of uromodulin mutations. The four newly identified mutants were characterized by immunofluorescence and FACS analysis on transfected cells. These experiments showed that all uromodulin mutations cause a delay in protein export to the plasma membrane due to a longer retention time in the endoplasmic reticulum. Immunohistochemistry on GCKD and MCKD/FJHN kidney biopsies revealed dense intracellular accumulation of uromodulin in tubular epithelia of the thick ascending limb of Henle's loop. Electron microscopy demonstrated accumulation of dense fibrillar material within the endoplasmic reticulum. Consistently, patient urines show a severe reduction of excreted uromodulin. The maturation impairment is consistent with the clinical findings and suggests a pathogenetic mechanism leading to these kidney diseases.

Evolution of the beta defensin 2 gene in primates

With the aim of further investigating the molecular evolution of beta defensin genes, after having analysed beta defensin 1 (DEFB1) in humans and several nonhuman primate species, we have studied the evolution of the beta defensin 2 gene (DEFB2), which codifies for a peptide with antimicrobial and chemoattractant activity, in humans and 16 primate species. We have found evidence of positive selection during the evolution of orthologous DEFB2 genes at two points on a phylogenetic tree relating these primates: during the divergence of the platyrrhines from the catarrhines and during the divergence of the Cercopithecidae from the Hylobatidae, Great Apes and humans. Furthermore, amino acid variations in Old World Monkeys seem to centre either on residues that are involved in oligomerisation in the human molecule, or that are conserved (40-80%) in beta-defensins in general. It is thus likely that these variations affect the biological function of the molecules and suggest that their synthesis and functional analysis might reveal interesting new information as to their role in innate immunity.

A reliable screening procedure for coeliac disease in clinical practice

BACKGROUND

The main autoantigen recognized by the sera of patients with coeliac disease (CD) is tissue transglutaminase (tTG). A human-recombinant form of tTG was used to develop an ELISA to measure anti-tTG serum antibodies for the diagnosis of CD. Preliminary retrospective reports suggest that the human tTG-based ELISA could identify coeliac patients missed by the IgA-anti-endomysium antibody test (AEA). Whether the human recombinant tTG ELISA is sufficiently accurate to become the main diagnostic CD tool in everyday clinical practice is unknown. The objective was to determine, in a prospective study, the sensitivity and specificity of an ELISA test based on the use of human tTG compared with AEA, to analyse the discordant cases for HLA DQ2-8 and for clinical and intestinal biopsy characteristics.

METHODS

1106 patients referred to a gastrointestinal outpatient clinic for symptoms attributable to CD, 52 first-degree relatives of CD patients and 200 healthy controls were tested for both anti-human tTG and AEA antibodies.

RESULTS

Out of 1158 subjects, 146 were tested positive for anti-tTG antibodies and 140 were biopsy-proven coeliacs. The AEA test identified 126/1158 coeliacs who also tested positive for anti-tTG antibodies. The 14 patients missed by the AEA test carried the typical HLA-DQ for CD; they had normal levels of total serum IgA and had milder pathology than those with both anti-tTG and AEA positivity (P < 0001).

CONCLUSIONS

These results prove that human tTG-based ELISA is an excellent diagnostic tool for CD, for mass screening by both the specialist and the general clinic.