Aryl Hydrocarbon Receptor Activation and Tissue Factor Induction by Fluid Shear Stress and Indoxyl Sulfate in Endothelial Cells.

Endogenous agonists of the transcription factor aryl hydrocarbon receptor (AHR) such as the indolic uremic toxin, indoxyl sulfate (IS), accumulate in patients with chronic kidney disease. AHR activation by indolic toxins has prothrombotic effects on the endothelium, especially via tissue factor (TF) induction. In contrast, physiological AHR activation by laminar shear stress (SS) is atheroprotective. We studied the activation of AHR and the regulation of TF by IS in cultured human umbilical vein endothelial cells subjected to laminar fluid SS (5 dynes/cm2). SS and IS markedly increased the expression of AHR target genes PTGS2 (encoding for COX2), AHRR, CYP1A1, and CYP1B1, as well as F3 (encoding for TF), in an AHR-dependent way. IS amplified SS-induced TF mRNA and protein expression and upregulation of AHR target genes. Interestingly, tyrosine kinase inhibition by genistein decreased SS- but not IS-induced TF expression. Finally, the increase in TF expression induced by laminar SS was not associated with increased TF activity. In contrast, IS increased TF activity, even under antithrombotic SS conditions. In conclusion, IS and SS induce AHR activation and AHR-dependent TF upregulation by different mechanisms. Impairment of the antithrombotic properties of shear stressed endothelium by toxic AHR agonists could favor cardiovascular diseases in CKD.

Hemodialysis vascular graft as a focus of persistent Q fever.

Vascular access infection is a frequent complication in hemodialysis patients. We report the second case worldwide of a prosthetic hemodialysis vascular graft infection by Coxiella burnetii, with intense hypermetabolism on PET-CT, Q fever serology consistent with persistent infection, and positive C. burnetii DNA in the blood and removed vascular graft.

Clinical and Prognostic Factors in Patients with IgG4-Related Kidney Disease.

BACKGROUND: IgG4-related kidney disease is a major manifestation of IgG4-related disease, a systemic fibroinflammatory disorder. However, the clinical and prognostic kidney-related factors in patients with IgG4-related kidney disease are insufficiently defined. METHODS: We conducted an observational cohort study using data from 35 sites in two European countries. Clinical, biologic, imaging, and histopathologic data; treatment modalities; and outcomes were collected from medical records. Logistic regression was performed to identify the possible factors related to an eGFR ≤30 ml/min per 1.73 m 2 at the last follow-up. Cox proportional hazards model was performed to assess the factors associated with the risk of relapse. RESULTS: We studied 101 adult patients with IgG4-related disease with a median follow-up of 24 (11-58) months. Of these, 87 (86%) patients were male, and the median age was 68 (57-76) years. Eighty-three (82%) patients had IgG4-related kidney disease confirmed by kidney biopsy, with all biopsies showing tubulointerstitial involvement and 16 showing glomerular lesions. Ninety (89%) patients were treated with corticosteroids, and 18 (18%) patients received rituximab as first-line therapy. At the last follow-up, the eGFR was below 30 ml/min per 1.73 m 2 in 32% of patients; 34 (34%) patients experienced a relapse, while 12 (13%) patients had died. By Cox survival analysis, the number of organs involved (hazard ratio [HR], 1.26; 95% confidence interval [CI], 1.01 to 1.55) and low C3 and C4 concentrations (HR, 2.31; 95% CI, 1.10 to 4.85) were independently associated with a higher risk of relapse, whereas first-line therapy with rituximab was protective (HR, 0.22; 95% CI, 0.06 to 0.78). At their last follow-up, 19 (19%) patients had an eGFR ≤30 ml/min per 1.73 m 2 . Age (odd ratio [OR], 1.11; 95% CI, 1.03 to 1.20), peak serum creatinine (OR, 2.74; 95% CI, 1.71 to 5.47), and serum IgG4 level ≥5 g/L (OR, 4.46; 95% CI, 1.23 to 19.40) were independently predictive for severe CKD. CONCLUSIONS: IgG4-related kidney disease predominantly affected middle-aged men and manifested as tubulointerstitial nephritis with potential glomerular involvement. Complement consumption and the number of organs involved were associated with a higher relapse rate, whereas first-line therapy with rituximab was associated with lower relapse rate. Patients with high serum IgG4 concentrations (≥5 g/L) had more severe kidney disease.

Presence of specific SARS-COV2 antibodies in hemodialysis patients and their caregivers after the first wave of COVID-19.

Hemodialysis (HD) patients are at risk for severe COVID-19 and cannot comply with social distancing. SARS-COV2 seroprevalence in French patients and caregivers after the first wave of COVID-19 is unknown. SeroCOVIDial is a prospective study conducted between June and December 2020. SARS-COV2 seroprevalence was evaluated by a rapid serological test (BIOSYNEX) in HD patients and caregivers, and the presence or not of anti-SARS-COV2 neutralizing or non-neutralizing antibodies in patients was also determined by ELISA and seroneutralization. In June 2020, 451 HD patients and 238 caregivers were included. Overall SARS-COV2 seroprevalence was 8.4% (patients) and 6.7% (caregivers), and was 87.1% (patients) and 90.0% (caregivers) in participants with a previously documented SARS-COV2 infection. Overall seroprevalence reached 13.8% (patients) and 12.6% (caregivers) following the second epidemic wave. During the follow-up, 38 (8.4%) patients died (9 of COVID-19). Among the 44 (10.6%) patients who became infected, only two were seropositive at M0. The levels of anti-SARS-COV2 antibodies decreased over time in patients and caregivers. The BIOSYNEX test showed 82.9% sensitivity and 97.7% specificity. Prevalence of anti-SARS-COV2 antibodies was low in HD patients and caregivers after the first epidemic wave but rose after the second wave. A rapid serological test showed good performances and could be useful for future monitoring of anti-SARS-COV2 antibodies.

Diagnostic performance of pulmonary ultrasonography and a clinical score for the evaluation of fluid overload in haemodialysis patients.

INTRODUCTION: There is no feasible benchmark in daily routine to estimate the hydration status of haemodialysis patients, which is essential to their management. OBJECTIVE: We performed a study in haemodialysis patients to assess the diagnostic performance of pulmonary ultrasound and clinical examination for the evaluation of fluid overload using transthoracic echocardiography as a gold standard. METHODS: Thirty-one patients receiving chronic haemodialysis patients were included. Evaluation of hydration status was assessed weekly before haemodialysis sessions using clinical and Echo Comet Score from pulmonary ultrasound and transthoracic echocardiography (reference method). RESULTS: Five patients had a transthoracic echocardiography overload. Compared with transthoracic echocardiography, the diagnostic performance of the clinical overload score has a sensitivity of 100%, a specificity of 77%, a positive predictive value of 50% and a negative predictive value of 100% with a κ of 0.79. Only orthopnoea (P=0.008), jugular turgor (P=0.005) and hepatic-jugular reflux (P=0.008) were significantly associated with transthoracic echocardiography overload diagnosis. The diagnostic performance of Echo Comet Score by pulmonary ultrasound has a sensitivity of 80%, a specificity of 58%, a positive predictive value of 26% and a negative predictive value of 94%. Ten patients (32.3%) had an increase of extravascular pulmonary water without evidence of transthoracic echocardiography or clinical overload. CONCLUSIONS: Our clinical score has a convincing diagnostic performance compared to transthoracic echocardiography and could be easily used in daily clinical routine to adjust dry weight. The evaluation of the overload using pulmonary ultrasound seems poorly correlated with the overload evaluated by transthoracic echocardiography. Extravascular pulmonary water undetected by clinical examination and transthoracic echocardiography remains a parameter that requires further investigation.

[Clinical management of patients with hemophilia A in nephrology: Diagnostic and therapeutic challenges illustrated by the cases of 2 patients]. / Prise en charge néphrologique des patients hémophiles A : difficultés diagnostiques et thérapeutiques illustrées par le cas de 2 patients.

Hemophilia A is an X-linked genetic hemorrhagic disorder characterized by a factor VIII deficiency. The availability of secured substitution products has led to a dramatic improvement of life expectancy in hemophiliac patients. Nowadays, adult hemophiliac patients may develop Chronic Kidney Disease (CKD) resulting from age-related comorbidities (hypertension, obesity, diabetes). In addition, the high prevalence of viral infections in this population exposes patients to an increased risk of CKD. The risk of hemorrhage in hemophiliac patients is a challenge for their clinical management, both for diagnostic procedures (kidney biopsy in particular) and for renal replacement therapy (dialysis or renal transplantation) when it is needed. This work provides an update of the literature data concerning the management of hemophiliac patients in nephrology, illustrated by the cases of two patients.