Indole 3-acetic acid, indoxyl sulfate and paracresyl-sulfate do not influence anemia parameters in hemodialysis patients

International audienceBackground: The main reason for anemia in renal failure patients is the insufficient erythropoietin production by the kidneys. Beside erythropoietin deficiency, in vitro studies have incriminated uremic toxins in the pathophysiology of anemia but clinical data are sparse. In order to assess if indole 3-acetic acid (IAA), indoxyl sulfate (IS), and paracresyl sulfate (PCS)-three protein bound uremic toxins-are clinically implicated in end-stage renal disease anemia we studied the correlation between IAA, IS and PCS plasmatic concentrations with hemoglobin and Erythropoietin Stimulating Agents (ESA) use in hemodialysis patients. Methods: Between June and July 2014, we conducted an observational cross sectional study in two hemodialysis center. Three statistical approaches were conducted. First, we compared patients treated with ESA and those not treated. Second, we performed linear regression models between IAA, IS, and PCS plasma concentrations and hemoglobin, the ESA dose over hemoglobin ratio (ESA/Hemoglobin) or the ESA resistance index (ERI). Third, we used a polytomous logistic regression model to compare groups of patients with no/low/high ESA dose and low/high hemoglobin statuses

Pepper Mild Mottle Virus, a Plant Virus Associated with Specific Immune Responses, Fever, Abdominal Pains, and Pruritus in Humans

Background: Recently, metagenomic studies have identified viable Pepper mild mottle virus (PMMoV), a plant virus, in the stool of healthy subjects. However, its source and role as pathogen have not been determined. Methods and Findings: 21 commercialized food products containing peppers, 357 stool samples from 304 adults and 208 stool samples from 137 children were tested for PMMoV using real-time PCR, sequencing, and electron microscopy. Anti-PMMoV IgM antibody testing was concurrently performed. A case-control study tested the association of biological and clinical symptoms with the presence of PMMoV in the stool. Twelve (57%) food products were positive for PMMoV RNA sequencing. Stool samples from twenty-two (7.2%) adults and one child (0.7%) were positive for PMMoV by real-time PCR. Positive cases were significantly more likely to have been sampled in Dermatology Units (p<10−6), to be seropositive for anti-PMMoV IgM antibodies (p = 0.026) and to be patients who exhibited fever, abdominal pains, and pruritus (p = 0.045, 0.038 and 0.046, respectively). Conclusions: Our study identified a local source of PMMoV and linked the presence of PMMoV RNA in stool with a specific immune response and clinical symptoms. Although clinical symptoms may be imputable to another cofactor, including spicy food, our data suggest the possibility of a direct or indirect pathogenic role of plant viruses in humans

Parvovirus 4 in French in-patients: a study of haemodialysis and lung transplant cohorts

International audienceThe epidemiology and the clinical implication of human parvovirus 4 (PARV4) in human populations is still under evaluation. The distribution of PARV4 DNA was determined in cohorts of French haemodialysis and lung transplant patients. Plasma samples (n=289) were tested for PARV4 by real-time PCR assay (ORF2), and amplification products selected at random were sequenced. Analysis of available serological and biological markers was also undertaken. Fifty-seven samples out of 185 (30.8%) were positive for PARV4 DNA in the cohort of haemodialysis patients. A higher prevalence of the virus was identified in individuals with markers of HBV infection. PARV4 was also identified in 14 out of 104 samples (13.5%) from lung transplant recipients, with no clear-cut association with available clinical markers. Point mutations located on the zone of real-time detection were identified for some amplification products. This study describes the detection of PARV4 in the blood of haemodialysis and lung transplanted patients with significant difference in prevalence in these two cohorts. Further studies will be needed in order to understand better both the potential implication in host health and the natural history of this virus

Fractalkine Expression Induces Endothelial Progenitor Cell Lysis by Natural Killer Cells

BACKGROUND: Circulating CD34(+) cells, a population that includes endothelial progenitors, participate in the maintenance of endothelial integrity. Better understanding of the mechanisms that regulate their survival is crucial to improve their regenerative activity in cardiovascular and renal diseases. Chemokine-receptor cross talk is critical in regulating cell homeostasis. We hypothesized that cell surface expression of the chemokine fractalkine (FKN) could target progenitor cell injury by Natural Killer (NK) cells, thereby limiting their availability for vascular repair. METHODOLOGY/PRINCIPAL FINDINGS: We show that CD34(+)-derived Endothelial Colony Forming Cells (ECFC) can express FKN in response to TNF-α and IFN-γ inflammatory cytokines and that FKN expression by ECFC stimulates NK cell adhesion, NK cell-mediated ECFC lysis and microparticles release in vitro. The specific involvement of membrane FKN in these processes was demonstrated using FKN-transfected ECFC and anti-FKN blocking antibody. FKN expression was also evidenced on circulating CD34(+) progenitor cells and was detected at higher frequency in kidney transplant recipients, when compared to healthy controls. The proportion of CD34(+) cells expressing FKN was identified as an independent variable inversely correlated to CD34(+) progenitor cell count. We further showed that treatment of CD34(+) circulating cells isolated from adult blood donors with transplant serum or TNF-α/IFN-γ can induce FKN expression. CONCLUSIONS: Our data highlights a novel mechanism by which FKN expression on CD34(+) progenitor cells may target their NK cell mediated killing and participate to their immune depletion in transplant recipients. Considering the numerous diseased contexts shown to promote FKN expression, our data identify FKN as a hallmark of altered progenitor cell homeostasis with potential implications in better evaluation of vascular repair in patients

Nanobacteria Are Mineralo Fetuin Complexes

“Nanobacteria” are nanometer-scale spherical and ovoid particles which have spurred one of the biggest controversies in modern microbiology. Their biological nature has been severely challenged by both geologists and microbiologists, with opinions ranging from considering them crystal structures to new life forms. Although the nature of these autonomously replicating particles is still under debate, their role in several calcification-related diseases has been reported. In order to gain better insights on this calciferous agent, we performed a large-scale project, including the analysis of “nanobacteria” susceptibility to physical and chemical compounds as well as the comprehensive nucleotide, biochemical, proteomic, and antigenic analysis of these particles. Our results definitively ruled out the existence of “nanobacteria” as living organisms and pointed out the paradoxical role of fetuin (an anti-mineralization protein) in the formation of these self-propagating mineral complexes which we propose to call “nanons.” The presence of fetuin within renal calculi was also evidenced, suggesting its role as a hydroxyapatite nucleating factor

Vancomycin-induced Henoch-Schönlein purpura: a case report

<p>Abstract</p> <p>Introduction</p> <p>Henoch-Schönlein purpura is a small-vessel systemic vasculitis. Although its exact pathophysiology remains unknown, Henoch-Schönlein purpura has been reported in association with various medical conditions including hypersensitivity. We report the case of a patient with vancomycin-induced Henoch-Schönlein purpura.</p> <p>Case presentation</p> <p>A 42-year-old Caucasian man who had previously undergone a heart transplant was diagnosed as having an intra-abdominal abscess after he underwent a Hartmann procedure. At 15 days after initiation of antibiotic therapy including vancomycin, he developed a purpuric rash of the lower limbs, arthralgia, and macroscopic hematuria. At that time, our patient was already on hemodialysis for end-stage renal disease. Henoch-Schönlein purpura was diagnosed. After a second 15-day course of vancomycin, a second flare of Henoch-Schönlein purpura occurred. Skin biopsies showed leucocytoclastic vasculitis with IgA deposits and eosinophils in the peri-capillary inflammatory infiltrate, suggesting an allergic mechanism. After vancomycin was stopped, we did not observe any further flares. Only five cases of isolated cutaneous vasculitis, one case of lupus-like syndrome and one case of Henoch-Schönlein purpura after vancomycin treatment have been described to date in the literature.</p> <p>Conclusions</p> <p>Clinicians should be aware that systemic vasculitis can be induced by some treatments. Vancomycin is a widely prescribed antibiotic. Occurrence of rare but serious Henoch-Schönlein purpura associated with vancomycin requires its prompt discontinuation.</p

Acute tubulointerstitial nephritis complicating Legionnaires' disease: a case report

<p>Abstract</p> <p>Introduction</p> <p>Legionnaires' disease is recognized as a multi-systemic illness. Afflicted patients may have pulmonary, renal, gastrointestinal tract and central nervous system complications. However, renal insufficiency is uncommon. The spectrum of renal involvement may range from a mild and transient elevation of serum creatinine levels to anuric renal failure requiring dialysis and may be linked to several causes. In our present case report, we would like to draw attention to the importance of the pathological documentation of acute renal failure by reporting a case of a patient with acute tubulointerstitial nephritis complicating Legionnaires' disease.</p> <p>Case presentation</p> <p>A 55-year-old Caucasian man was admitted to our hospital for community-acquired pneumonia complicated by acute renal failure. <it>Legionella pneumophila </it>serogroup type 1 was diagnosed. Although the patient's respiratory illness responded to intravenous erythromycin and ofloxacin therapy, his renal failure worsened, he became anuric, and hemodialysis was started. A renal biopsy was performed, which revealed severe tubulointerstitial nephritis. After initiation of steroid therapy, his renal function improved dramatically.</p> <p>Conclusions</p> <p>This case highlights the importance of kidney biopsies in cases where acute renal failure is a complicating factor in Legionnaires' disease. If the presence of acute tubulointerstitial nephritis can be confirmed, it will likely respond favorably to steroidal treatment and thus irreversible renal damage and chronic renal failure will be avoided.</p

High Resolution Melt analysis for mutation screening in PKD1 and PKD2

<p>Abstract</p> <p>Background</p> <p>Autosomal dominant polycystic kidney disease (ADPKD) is the most common hereditary kidney disorder. It is characterized by focal development and progressive enlargement of renal cysts leading to end-stage renal disease. <it>PKD1 </it>and <it>PKD2 </it>have been implicated in ADPKD pathogenesis but genetic features and the size of <it>PKD1 </it>make genetic diagnosis tedious.</p> <p>Methods</p> <p>We aim to prove that high resolution melt analysis (HRM), a recent technique in molecular biology, can facilitate molecular diagnosis of ADPKD. We screened for mutations in <it>PKD1 </it>and <it>PKD2 </it>with HRM in 37 unrelated patients with ADPKD.</p> <p>Results</p> <p>We identified 440 sequence variants in the 37 patients. One hundred and thirty eight were different. We found 28 pathogenic mutations (25 in <it>PKD1 </it>and 3 in <it>PKD2 </it>) within 28 different patients, which is a diagnosis rate of 75% consistent with literature mean direct sequencing diagnosis rate. We describe 52 new sequence variants in <it>PKD1 </it>and two in <it>PKD2</it>.</p> <p>Conclusion</p> <p>HRM analysis is a sensitive and specific method for molecular diagnosis of ADPKD. HRM analysis is also costless and time sparing. Thus, this method is efficient and might be used for mutation pre-screening in ADPKD genes.</p