Inflammatory bowel disease (IBD) is described as a relapsing condition with high morbidity and uncertain complex pathogenesis. The association of Mycobacterium avium ssp. paratuberculosis (MAP) with Crohn’s disease (CD) in human has been debated for decades, however there is no confirmed data to verify such relations in Iran. The aim of this study was to investigate risk factors and a possible role of MAP in Iranian patients with CD.
Anti-MAP antibodies were detected in serum of IBD patients and subjects without IBD (nIBD) through ELISA; MAP DNA and viable MAP cells were identified in patients’ biopsies through nested PCR and direct culture methods, respectively. Principal component analysis (PCA) was used to investigate the risk factors in relation to IBD and MAP infection.
Positivity for IS900 PCR was detected in 64% (n = 18) of CD, 33% (n = 10) of ulcerative colitis (UC) and 9.7% (n = 6) of nIBD samples. Live MAP cells were isolated from biopsies of 2 CD patients only. Among 28 patients with CD, 46% (n = 13) and 39% (n = 11) were positive for antibodies against MAP3865c133–141 and MAP3865c125–133 peptides, respectively, whereas much lower seroreactivity was detected in UC subjects accounting for 3% (n = 1) for MAP3865c133–141 and 16.7% (n = 5) for MAP3865c125–133. A high immune reactivity to MAP epitopes among CD patients was positively correlated with consumption of fast food meals and IBD familiarity. For both CD and UC, breastfeeding period and consumption of fruit/vegetables presented negative correlation with the presence of anti-MAP antibodies.
This study provided evidences that high prevalence of MAP DNA and anti-MAP antibodies in CD patients is significantly associated with the development of CD. Despite the role of several factors contributing to IBD, the presence of MAP DNA and anti-MAP antibodies in Iranian CD patients highlights a possible transmission of MAP from animal-derived products to humans.
Mycobacterium avium subsp. paratuberculosis; Inflammatory bowel disease; Crohn’s disease; ELISA; IS900 nested PCR; Iran
Elevated B lymphocyte activating factor BAFF levels have been reported in multiple sclerosis (MS) patients; moreover, disease-modifying treatments (DMT) have shown to influence blood BAFF levels in MS patients, although the significance of these changes is still controversial. In addition, BAFF levels were reported increased during infectious diseases. In our study, we wanted to investigate on the serum BAFF concentrations correlated to the antibody response against Mycobacterium avium subspecies paratuberculosis (MAP), Epstein-Barr virus (EBV) and their human homologous epitopes in MS and in patients affected with other neurological diseases (OND), divided in Inflammatory Neurological Diseases (IND), Non Inflammatory Neurological Diseases (NIND) and Undetermined Neurological Diseases (UND), in comparison to healthy controls (HCs). Our results confirmed a statistically significant high BAFF levels in MS and IND patients in comparison to HCs but not NIND and UND patients. Interestingly, BAFF levels were inversely proportional to antibodies level against EBV and MAP peptides and the BAFF levels significantly decreased in MS patients after methylprednisolone therapy. These results implicate that lower circulating BAFF concentrations were present in MS patients with humoral response against MAP and EBV. In conclusion MS patients with no IgGs against EBV and MAP may support the hypothesis that elevated blood BAFF levels could be associated with a more stable disease.
Several works have demonstrated the existence of a link between Mycobacterium avium subsp. paratuberculosis (MAP) and MS in Italy. In this study, we analyzed the serology of MAP in a Japanese population while looking at several markers of MAP. Fifty MS patients, 12 clinically isolated syndrome (CIS) patients, 30 other neurological disorders (OND) patients, and 50 healthy controls (HCs) were tested using ELISA for the presence of IgG antibodies toward immunodominant epitopes MAP_0106c121-132, homologues MBP85-98, homologues IRF5424-432, MAP_402718-32, and MAP_2694295-303. MAP-positive patients were also analyzed in relation to their clinical/demographic characteristics. Amongst all peptides, only antibodies against MAP_2694295-303 were more prevalent in MS patients (30%), as compared to OND patients (3%) (p = 0.009; area under roc curve (AUC) = 0.61) and HCs (2%) (p = 0.0004; AUC = 0.65) and in CIS patients (25%) compared to HCs (p = 0.023; AUC = 0.55). Logistic regression analysis showed a higher frequency of anti-MAP_2694295-303 antibodies in the sera of oligoclonal bands positive MS patients (p = 0.2; OR = 2, 95%CI: 0.55–7.7). These findings support the view that MAP could act as a risk factor or a triggering agent of MS in some Japanese patients with a genetic susceptibility to the mycobacterium.
Although numerous environmental agents have been investigated over the years as possible triggers of type 1 diabetes (T1D), its causes remain unclear. We have already demonstrated an increased prevalence of antibodies against peptides derived from Mycobacterium avuim subsp. paratuberculosis (MAP) homologous to human zinc transporter 8 protein (ZnT8) and proinsulin in Italian subjects at risk for or affected by T1D. In this study, we compared titers of the previously detected antibodies with seroreactivity to MAP lipopentapetide (L5P) that recently emerged as a strong immunogenic component able to specifically distinguish MAP from other mycobacteria.
Plasma of 32 children and youth at risk for T1D including follow-up samples and 42 age-matched healthy controls (HC) recruited at the Tor Vergata University Hospital in Rome was analyzed by indirect ELISA for the presence of antibodies against MAP-derived epitopes MAP3865c133–141, MAP3865c125-133, MAP2404c70-85 and MAP1,4αgbp157-173 along with their ZnT8 and proinsulin homologs. The data were analyzed through two-tailed Mann-Whitney U test and relation between variables was determined by principal component analysis.
Responses to L5P were not detectable in subjects whose initial seroreactivity to MAP peptides and their human homologs was lost in follow-up samples, whereas anti-L5P antibodies appeared constantly in individuals with a stable immunity against MAP antigens. The overall coincidence in positivity to L5P and the four MAP epitopes both in children at risk for T1D and HC exceeded 90%.
MAP-derived homologs may cross-react with ZnT8 and proinsulin peptides inducing immune responses at a young age in subjects predisposed for T1D. Thus, L5P may have a diagnostic value to immediately indicate the presence of anti-MAP seroreactivity when evaluation of a more complex antibody status is not required. Almost complete coincidence in responses to both types of antigens lends support to the involvement of MAP in T1D.
MicroRNAs fine-tune the regulation of Th1/Th17 lymphocyte subsets in multiple sclerosis. We investigated the expression of miRNAs (previously associated with mycobacterial and viral infections) in MS patients and healthy donors (HD) following 6 months natalizumab therapy. In addition, Th1/Th17 cytokines and the presence of anti-EBNA1/VCA IgG in MS patients with different pattern of miRNA expression have been evaluated. MiR-155, miR-26a, miR-132, miR-146a and Th1/Th17 cytokines expression was detected by RT-real time PCR; moreover anti-EBNA1 and VCA IgG titres were measured by ELISA. We observed an up-regulation of miR-155 (p value = 0.009) and miR-132 (p value = 0.04) in MS patients compared to HD. In MS patients, IL-17a (p = 0.037), IFN γ (p = 0.012) and TNFα (p = 0.015) but not IL-6 were over-expressed compared to HD. Two different miRNAs patterns associated to the expression of different cytokines were observed in the MS cohort. Moreover, a down-regulation of miR-155 and miR-26a was seen in MS patients during and after natalizumab therapy. MS patients that over-expressed miR-155 showed a higher EBNA1 IgG titer than MS patients with high levels of miR-26a. In conclusions the expression of particular miRNAs modulates the pro-inflammatory cytokine expression and the humoral response against EBV and this expression is natalizumab regulated.
Mycobacterium avium subsp. paratuberculosis (MAP) and Epstein-Barr virus (EBV) epitopes elicit a consistent humoral response in serum of multiple sclerosis patients, but the cross reactivity against the homologous myelin basic protein (MBP) and human interferon regulatory factor 5 (IRF5) has not been searched within the Cerebral Spinal Fluid (CSF). We evaluated in sera and CSF of patients with MS and with other neurological diseases (OND) the humoral response against EBV/MAP peptides and the IRF5/MBP. Our data showed that EBV and MAP peptides are able to induce a specific humoral immune response in MS patients compared to OND controls both in serum and in CSF. An intrathecal specific synthesis of IgG against MBP and their EBV and MAP homologous as indicated by the antibody index was observed in MS patients. The humoral response against EBV, MAP, MBP and IRF5 was significantly higher in MS patients compared to OND both in serum and in CSF. The higher presence of antibodies against MBP and their MAP and EBV homologous in CSF during relapses suggests a possible role of the pathogens in enhancing inflammation.
Aldosterone is considered to exert direct effects on the myocardium and the sympathetic nervous system. Both QT time and heart rate (HR) variability (HRV) are considered to be markers of arrhythmic risk and autonomous dysregulation. In this study, we investigated the associations between aldosterone, QT time, and HRV in patients with arterial hypertension.
We recruited 477 hypertensive patients (age: 60.2 ± 10.2 years; 52.3% females) with a mean systolic/diastolic 24-hour ambulatory blood pressure monitoring (ABPM) value of 128 ± 12.8/77.1 ± 9.2 mmHg and with a median of 2 (IQR: 1–3) antihypertensive agents. Patients were recruited from the outpatient clinic at the Department of Internal Medicine of the Medical University of Graz, Austria. Blood samples, 24-hour HRV derived from 24-hour blood pressure monitoring (ABPM) and ECG's were obtained. Plasma aldosterone and plasma renin concentrations were measured by means of a radioimmunoassay. Twenty-four-hour urine specimens were collected in parallel with ABPM.
Mean QTc was 423.3 ± 42.0 milliseconds for males and 434.7 ± 38.3 milliseconds for females. Mean 24H-HR and 24H-HRV was 71.9 ± 9.8 and 10.0 ± 3.6 bpm, respectively. In linear regression analyses adjusted for age, sex, body mass index, ABPM, and current medication, aldosterone to active renin ratio (AARR) was significantly associated with the QTc interval, a marker for cardiac repolarization abnormalities (mean = 426 ± 42.4 milliseconds; β-coefficient = 0.121; P = 0.03) as well as with the 24-hour heart rate variability a surrogate for autonomic dysfunction (median = 9.67 [IQR = 7.38–12.22 bpm]; β-coefficient = −0.133; P = 0.01).
In hypertensive patients, AARR is significantly related to QTc prolongation as well as HRV. Further studies investigating the effects of mineralocorticoid receptor blocker and aldosterone synthase inhibitors on QTc and HRV are warranted.
Mycobacterium avium subspecies paratuberculosis (MAP) has been previously associated to T1D as a putative environmental agent triggering or accelerating the disease in Sardinian and Italian populations. Our aim was to investigate the role of MAP in T1D development by evaluating levels of antibodies directed against MAP epitopes and their human homologs corresponding to ZnT8 and proinsulin (PI) in 54 T1D at-risk children from mainland Italy and 42 healthy controls (HCs). A higher prevalence was detected for MAP/ZnT8 pairs (62,96% T1D vs. 7,14% HCs; p < 0.0001) compared to MAP/PI epitopes (22,22% T1D vs. 9,52% HCs) and decreasing trends were observed upon time-point analyses for most peptides. Similarly, classical ZnT8 Abs and GADA decreased in a time-dependent manner, whereas IAA titers increased by 12%. Responses in 0–9 year-old children were stronger than in 10–18 age group (75% vs. 69,1%; p < 0.04). Younger age, female sex and concomitant autoimmune disorders contributed to a stronger seroreactivity suggesting a possible implication of MAP in multiple autoimmune syndrome. Cross-reactivity of the homologous epitopes was reflected by a high correlation coefficient (r2 > 0.8) and a pairwise overlap of positivity (>83% for MAP/ZnT8).
As numerous studies put in evidence the increasing incidence of type 1 diabetes (T1D) in children, an early diagnosis is of great importance to define correct treatment and diet. Currently, the identification of classical islet autoantibodies is the primary biomarker for diagnosis in subjects at risk, especially in pediatric patients. Recent studies suggest that detection of antibodies against ZnT8 protein in preclinical phase can predict the development of T1D. We previously demonstrated a significant association of Mycobacterium avium subspecies paratuberculosis (MAP) with T1D in adult Sardinian patients. To enforce this finding, we investigated the presence of antibodies against ZnT8 and proinsulin (PI) with respective homologous epitopes: MAP3865c133–141/ZnT8186–194, MAP3865c125–133/ZnT8178–186, MAP2404c70–85/PI46–61, and MAP1,4αgbp157–173/PI64–80, in 23 children at risk for T1D, formerly involved in the TRIGR study, and 22 healthy controls (HCs). Positivity to anti-MAP and homologous human peptides was detected in 48% of at-risk subjects compared to 5,85% HCs, preceding appearance of islet autoantibodies. Being MAP easily transmitted to humans with infected cow's milk and detected in retail infant formulas, MAP epitopes could be present in extensively hydrolyzed formula and act as antigens stimulating β-cell autoimmunity.
Developmentally early cells are mobilized into peripheral blood in Crohn’s disease (CD) patients. OCT4, is considered to be important in sustaining the pluripotency of stem cells. OCT4 splicing variants are differentially expressed in pluripotent and non-pluripotent cells. Our study aims to investigate the expression pattern of OCT4 variants and SOX-2, an essential factor implicated in self-renewal and pluripotency, in tissue and blood samples from patients with IBD.
Peripheral blood and tissue samples were collected from patients with active CD and ulcerative colitis (UC), and from healthy individuals. OCT4 expression was documented by Western blot, immunohistochemistry and by reverse transcription-real-time PCR. OCT4 isoform determination was documented using specific primers. SOX-2 expression levels were also evaluated.
OCT4 protein levels were significantly higher in CD tissue samples than in CD blood samples, and in UC tissue samples. OCT4 protein was localized mainly in the cytosol. In all samples, only the OCT4 pseudogenes and the OCT4B1 variant were detected. OCT4B1 expression levels were elevated in both tissue and blood samples from CD and UC cases compared to healthy controls. In CD patients only SOX-2 mRNA levels were found slightly increased compared to healthy controls.
Our results suggest that OCT4 is expressed in patients with IBD. Furthermore, we found the presence of the OCT4B1 isoform in IBD in both tissue and blood samples. Our results have shown, that developmentally early cells might be mobilized into peripheral blood as result of tissue damage, indicating a possible role of these cells in repair of injured intestinal tract.
IBD; Crohn’s disease; Ulcerative colitis; Stem cells; Mobilization
Hashimoto’s thyroiditis (HT) is the prevailing organ-specific autoimmune disease in Sardinia, often complicated with other autoimmune disorders, most commonly type 1 diabetes (T1D). While numerous studies describe levels of anty-thyroid antibodies (Abs) in T1D patients, few papers evaluate the status of anti-islet autoimmunity in subjects affected by HT. Previously, we portrayed Mycobacterium avium subspecies paratuberculosis (MAP) as an environmental factor strongly associated with both diseases. In this study, we analyzed plasma of Sardinian HT patients (n=177) and healthy controls (HCs; n=175) for the presence of Abs against proinsulin and MAP-derived homologous epitopes: MAP1,4αgbp157-173/PI64-80 were recognized by 5,08% and 18,64% of HT vs 0,57% and 7,43% of HCs (AUC=0,6 for both; p<0,0003 and 0,002, respectively), whereas the prevalence of Abs against MAP2404c70-85/PI46-61 peptides was higher but not significant in patients when compared to HCs. In women (n=152), Abs against MAP1,4αgbp157-173 were detected in 12,50% of HT vs 2,75% of HCs (AUC=0,63; p<0,0002), while positivity to its human homolog PI64-80 was observed in 16,42% of HT vs 6,42% of HCs (AUC=0,61; p<0,001). In men (n=25), a significant anti-PI46-61 Abs levels were detected in 4% of HT vs none of the HCs (AUC=0,7; p<0,003). Age-related analyses revealed the highest prevalence between 31-40 years old (45,83%) in the total study population and among males (33,33%); in contrast, women had a higher seroreactivity between 51-60 years (42,11%). A further follow-up and determination of anti-islet Abs levels is needed to evaluate the association of immune responses directed against the MAP/PI homologous peptides with progression to overt diabetes in HT subjects.
Patients with renal failure are at increased risk of cardiovascular events even at the earliest stages of disease. In addition to many classic cardiovascular risk factors, many conditions that are commonly identified as emerging risk factors might contribute to occurrence of cardiovascular disease. Changes in circulating levels of many of these emerging risk factors have been demonstrated in patients with early stages of renal failure caused by different types of renal disease and have been associated with detection of cardiovascular complications. However, for most of these factors evidence of benefits of correction on cardiovascular outcome is missing. In this article, we comment on the role of lipoprotein(a) and prothrombotic factors as potential contributors to cardiovascular events in patients with early renal failure.
Early renal failure; Cardiovascular disease; Risk factors; Lipoprotein(a); Prothrombotic state
Primary aldosteronism is a frequent form of secondary hypertension that had long been considered relatively benign. Experimental and clinical evidence collected in the last two decades, however, has clearly demonstrated that this endocrine disorder is associated with excess cardiovascular and renal complications as compared to essential hypertension. These complications reflect the ability of inappropriate elevation of plasma aldosterone to cause tissue damage beyond that induced by high blood pressure itself, thereby setting the stage for major cardiovascular and renal disease. Because of the impact of elevated aldosterone on organ damage, goals of treatment in patients with primary aldosteronism should not be limited to normalization of blood pressure, and prevention or correction of organ complications is mandatory. Treatment with mineralocorticoid receptor antagonists or unilateral adrenalectomy is the respective options for treatment of idiopathic adrenal hyperplasia or aldosterone-producing adenoma. Last years have witnessed a rapid growth in knowledge concerning the effects of these treatments on cardiovascular and renal protection. This paper is an overview of the cardiovascular and renal complications that occur in patients with primary aldosteronism and a summary of the results that have been obtained in the long term on cardiovascular and renal outcomes with either medical or surgical treatment.
Diagnosis of extrapulmonary tuberculosis (TB) is often challenging. In this work we discuss the utility of an assay for Lipoarabinomannan (LAM) antibody detection in synovial fluid. LAM is one of the three major groups of lipopolysaccharides within the Mycobacterium tuberculosis (MTB) cell wall. An ELISA based test was used to investigate the presence of antibodies against LAM in an immunocompetent patient with knee arthritis. The symptoms resolved after isoniazid treatment. LAM positivity has been used as a diagnostic tool for TB in different settings, including veterinary field. The test could be of some value to diagnose tuberculous arthritis in selected patients when gold standard test returned negative although further investigations are welcome.
Arthritis; Mycobacteria; ELISA; Lipoarabinomannan
The factitive role of Mycobacterium avium ss. paratuberculosis (MAP) in Crohn’s disease has been debated for more than a century. The controversy is due to the fact that Crohn’s disease is so similar to a disease of MAP-infected ruminant animals, Johne’s disease; and, though MAP can be readily detected in the infected ruminants, it is much more difficult to detect in humans. Molecular techniques that can detect MAP in pathologic Crohn’s specimens as well as dedicated specialty labs successful in culturing MAP from Crohn’s patients have provided strong argument for MAP’s role in Crohn’s disease. Perhaps more incriminating for MAP as a zoonotic agent is the increasing number of diseases with which MAP has been related: Blau syndrome, type 1 diabetes, Hashimoto thyroiditis, and multiple sclerosis. In this article, we debate about genetic susceptibility to mycobacterial infection and human exposure to MAP; moreover, it suggests that molecular mimicry between protein epitopes of MAP and human proteins is a likely bridge between infection and these autoimmune disorders.
paratuberculosis; MAP; Crohn’s; autoimmune; molecular mimicry; type 1 diabetes; autoimmune thyroiditis; multiple sclerosis
MAP3865c, a Mycobacterium avium subspecies paratuberculosis (MAP) cell membrane protein, has a relevant sequence homology with zinc transporter 8 (ZnT8), a beta-cell membrane protein involved in Zn++ transportation. Recently, antibodies recognizing MAP3865c epitopes have been shown to cross-react with ZnT8 in type 1 diabetes patients. The purpose of this study was to detect antibodies against MAP3865c peptides in patients with high-risk proliferative diabetic retinopathy and speculate on whether they may somehow be involved in the pathogenesis of this severe retinal disorder.
Blood samples were obtained from 62 type 1 and 80 type 2 diabetes patients with high-risk proliferative diabetic retinopathy and 81 healthy controls. Antibodies against 6 highly immunogenic MAP3865c peptides were detected by indirect ELISA.
Type 1 diabetes patients had significantly higher rates of positive antibodies than controls. Conversely, no statistically significant differences were found between type 2 diabetes patients and controls. After categorization of type 1 diabetes patients into two groups, one with positive, the other with negative antibodies, we found that they had similar mean visual acuity (∼0.6) and identical rates of vitreous hemorrhage (28.6%). Conversely, Hashimoto's thyroiditis prevalence was 4/13 (30.7%) in the positive antibody group and 1/49 (2%) in the negative antibody group, a statistically significant difference (P = 0.016).
This study confirmed that type 1 diabetes patients have significantly higher rates of positive antibodies against MAP/ZnT8 peptides, but failed to find a correlation between the presence of these antibodies and the severity degree of high-risk proliferative diabetic retinopathy. The significantly higher prevalence of Hashimoto's disease among type 1 diabetes patients with positive antibodies might suggest a possible common environmental trigger for these conditions.
Mycobacterium avium subspecies paratuberculosis (MAP) asymptomatic infection has been previously linked to Type 1 diabetes (T1D) and Multiple Sclerosis. An association between MAP infection and Hashimoto's thyroiditis (HT) was also proposed only in a case report. This study aimed to investigate the robustness of the latter association, testing a large cohort of HT and healthy control (HCs) subjects, all from Sardinia. Prevalence of anti-MAP3865c Abs was assessed by indirect enzyme-linked immunosorbent assay (ELISA). Moreover, given that human ZnT8 is specifically expressed in the pancreatic β-cells, in the follicle epithelial cells and in the parafollicular cells of the thyroid gland, we also tested ZnT8 epitopes homologues to the MAP3865c immunodominant peptides previously identified. Indeed, Abs targeting MAP3865c and ZnT8 homologous regions display similar frequencies in patients and controls, thus suggesting that Abs recognizing these epitopes could be cross-reactive. A statistically significant difference was found between HT patients and HCs when analyzing the humoral response mounted against MAP3865c/ZnT8 homologues epitopes. To our knowledge, this is the first report, which provides statistically significant evidence sustaining the existence of an association between MAP sero-reactivity and HT. Further studies are required to investigate the relevance of MAP to HT, aimed at deciphering if this pathogen can be at play in triggering this autoimmune disease. Likewise, genetic polymorphism of the host, and other environmental factors need to be investigated.
Receptors for mineralocorticoid hormones are expressed in myocardial cells and evidence obtained in animal studies suggests that activation of these receptors causes cardiac damage independent from blood pressure levels. In the last years, many of the issues related to the effects of aldosterone on the heart have received convincing answers and clinical investigation has focused on a variety of conditions including systolic and diastolic heart failure, arrhythmia, primary hypertension, and primary aldosteronism. Some issues, however, await clarification in order to obtain better understanding of what could be the role of aldosterone blockade in prevention and treatment of cardiovascular diseases. In this article, we overview the most recent findings of animal studies that have examined the contribution of aldosterone to cardiac function and clinical studies that have investigated the influence of aldosterone on left ventricular structure and function in the setting of primary hypertension and primary aldosteronism.
aldosterone; aldosterone-producing adenoma; bilateral adrenal hyperplasia; echocardiography; left ventricular hypertrophy; left ventricular mass; adrenalectomy; mineralocorticoid receptor antagonists
Our group has recently demonstrated that Mycobacterium avium subspecies paratuberculosis (MAP) infection significantly associates with T1D in Sardinian adult patients. Due to the potential role played by MAP in T1D pathogenesis, it is relevant to better characterize the prevalence of anti-MAP antibodies (Abs) in the Sardinian population, studying newly diagnosed T1D children. Therefore, we investigated the seroreactivity against epitopes derived from the ZnT8 autoantigen involved in children at T1D onset and their homologous sequences of the MAP3865c protein. Moreover, sera from all individuals were tested for the presence of Abs against: the corresponding ZnT8 C-terminal region, the MAP specific protein MptD, the T1D autoantigen GAD65 and the T1D unrelated Acetylcholine Receptor. The novel MAP3865c281–287 epitope emerges here as the major C-terminal epitope recognized. Intriguingly ZnT8186–194 immunodominant peptide was cross-reactive with the homologous sequences MAP3865c133–141, strengthening the hypothesis that MAP could be an environmental trigger of T1D through a molecular mimicry mechanism. All eight epitopes were recognized by circulating Abs in T1D children in comparison to healthy controls, suggesting that these Abs could be biomarkers of T1D. It would be relevant to investigate larger cohorts of children, followed over time, to elucidate whether Ab titers against these MAP/Znt8 epitopes wane after diagnosis.
Mycobacterium avium subsp. paratuberculosis (MAP) is the cause of Johne’s disease, an enteric granulomatous disease. Recently, MAP has been associated with different autoimmune diseases such as Crohn’s disease, type 1 diabetes (T1D) and multiple sclerosis. Transthyretin (TTR) is a plasma transport protein for thyroid hormone and forms a complex with retinol-binding protein. Reduced TTR plasma levels in MAP infected ovines have been reported.
TTR exerts also a functional role in the pancreas promoting insulin release and protecting β-cells from death.
Our objective was to identify a protein that could be used as a diagnostic marker of T1D for determining disease progression and monitoring at-risk patients. We postulate that serological TTR levels would be reduced in T1D MAP exposed patients. Our hypothesis is based on the observation of cases of T1D patients with decreased TTR levels beside the reduced TTR plasma levels in ovines with Johne’s disease.
We quantified the plasma protein levels of TTR in 50 people with T1D and 51 age-matched healthy controls (HCs) by means of enzyme-linked immunosorbent assays (ELISA).
Our pilot study showed that plasma TTR levels were not significantly lower/higher in T1D Sardinian cases compared to the HCs.
These preliminary data indicate that plasma TTR may not be a good candidate biomarker for T1D diagnosis and further studies to elucidate the possible link are needed.
Mycobacterium avium subsp. paratuberculosis; Type 1 diabetes; Transthyretin; Biomarker; Sardinia
Mycobacterium avium subsp. paratuberculosis (MAP) is a zoonotic pathogen, a very slow growing bacterium which is difficult to isolate and passage in conventional laboratory culture. Although its association with Johne’s disease or paratuberculosis of cattle is well established, it has been only putatively linked to Crohn’s disease in humans. Further, MAP has been recently suggested to be a trigger for other autoimmune diseases such as type-1 diabetes mellitus (T1DM). Recently, some studies have indicated that exposure to MAP is associated with elevated levels of antibodies against MAP lysate although the exact mechanism and significance of the same remains unclear. Further, the cytokine profiles relevant in MAP associated diseases of humans and their exact role in the pathophysiology are not clearly known. We performed in vitro cytokine analyses after exposing different cultured human cells to the whole cell lysate of MAP and found that MAP lysate induces secretion of cytokines IL-1β, IL-6, IL-8, IL-10 and TNF-α by human peripheral blood mononuclear cells (PBMCs). Also, it induces secretion of IL-8 by cultured human stomach adenocarcinoma cells (AGS) and PANC-1(human pancreatic carcinoma cell line) cells. We also found that MAP lysate induced cytotoxicity in PANC-1cells. Collectively, these results provide a much needed base-line data set of cytokines broadly signifying a MAP induced cellular response by human cells.
Mycobacterium avium subsp. paratuberculosis (MAP) is the etiological agent of Johne's disease in ruminants. Recent studies have linked MAP to type 1 diabetes (T1D) in the Sardinian population. The aim of this study was to investigate the prevalence of MAP infection in a T1D cohort from continental Italy compared with healthy control subjects. 247 T1D subjects and 110 healthy controls were tested for the presence of MAP. MAP DNA was detected using IS900-specific polymerase chain reaction (PCR). The presence of antibodies towards a MAP antigen, heparin binding hemoagglutinin (HBHA), was detected by ELISA. We demonstrated a higher MAP DNA prevalence in plasma samples from T1D patients and a stronger immune response towards MAP HBHA, compared with healthy control subjects. Moreover, in the recent onset patients, we observed an association between anti-MAP antibodies and HLA DQ2 (DQA1 0201/DQB1 0202).
These findings taken together support the hypothesis of MAP as an environmental risk factor for the development of T1D in genetically predisposed subjects, probably involving a mechanism of molecular mimicry between MAP antigens and pancreatic islet β-cells.
Recent studies have identified in Mycobacterium avium subsp. paratuberculosis (MAP), already known as a pathogen in ruminants, a potential zoonotic agent of some autoimmune diseases in humans. Therefore, considering the possible risk for public health, it is necessary a thorough understanding of MAP's gene expression during infection of human host as well as the identification of its immunogenic and/or virulence factors for the development of appropriate diagnostic and therapeutic tools.
In order to characterize MAP's transcriptome during macrophage infection, we analyzed for the first time the whole gene expression of a human derived strain of MAP in simulated intraphagosomal conditions and after intracellular infection of the human macrophage cell line THP-1 by using the DNA-microarray technology. Results showed that MAP shifts its transcriptome to an adaptive metabolism for an anoxic environment and nutrient starvation. It up-regulates several response factors to oxidative stress or intracellular conditions and allows, in terms of transcription, a passive surface peptidoglycan spoliation within the macrophage along with an intensification of the anabolic activity for lipidic membrane structures.
These results indicate a possible interactive system between MAP and its host cell based on the internal mimicry unlike other intracellular pathogens, bringing new hypothesis in the virulence and pathogenicity of MAP and its importance in human health.
Mycobacterium avium subsp. paratuberculosis; functional genomics; DNA-microarray; simulated intra-phagosomal multi-stress; macrophage infection
Experimental and clinical studies indicate that exposure to high aldosterone concentrations causes cardiac damage independent of the blood pressure level. In recent years, it has become clear that the effects of aldosterone on the heart are mediated by actions on a variety of cell types and intracellular mechanisms that contribute to regulation of specific tissue responses, leading to hypertrophy and fibrosis. Most cardiac effects of aldosterone are mediated by activation of mineralocorticoid receptors that are detected in cardiac myocytes and fibroblasts. Clinical evidence of the unfavorable cardiac effects of aldosterone has been established in landmark studies that have tested the benefits of aldosterone antagonists in patients with heart failure and decreased ejection fraction. However, evidence of benefits of aldosterone antagonists occurring independent of the renal effects of these agents is not limited to patients with systolic heart failure. In this article, we briefly summarize the current knowledge on the effects of aldosterone antagonists on cardiac protection and highlight the most recent findings that have been obtained in different cardiac conditions with use of these drugs.
Aldosterone; aldosterone antagonists; atrial fibrillation; diastolic cardiac failure; essential hypertension; primary aldosteronism