IL-8 production by peripheral blood mononuclear cells in nephrotic patients

IL-8 production by peripheral blood mononuclear cells in nephrotic patients. We studied the interleukin 8 (IL-8) gene expression by peripheral blood mononuclear cells (PBMC) and the IL-8 serum concentration in patients with idiopathic minimal lesion nephrotic syndrome (IMLNS) and other glomerulopathies. PBMC from eight of the nine (IMLNS) patients in relapse demonstrated the presence of IL-8 mRNA. All three IMLNS patients in remission (P = 0.0026 when compared to patients in relapse) and the two patients with nephrotic syndrome with other glomerulopathies failed to elicit an IL-8 mRNA response. Eleven of the 12 IMLNS patients in relapse showed IL-8 serum concentration above the level of detection. Only one of the seven patients in remission had detectable serum levels of IL-8 (P = 0.0033 when compared to levels from IMLNS patients in relapse). IL-8 serum levels were not detectable in three patients with nephrotic syndrome and other glomerulopathies. Supernatants of PBMC cultures from IMLNS patients in relapse increased the 35sulfate uptake by rat GBM. This effect was abolished by the addition of anti-IL-8 neutralizing antibody to the culture media and reproduced by the addition to the media of IL-8 in concentrations found in the serum of IMLNS patients in relapse. Finally, the effect of IL-8 on the 35sulfate turnover of the glomerular basement membrane (GBM) sulfated compounds was evaluated in vitro. A significant decrease in the percentage of residual 35sulfate incorporated in the GBM (41 ± 5, mean ± sem) was observed in cultures treated with IL-8 as compared to those that were not treated with IL-8 (58 ± 8, P < 0.01). Because IL-8 affects the metabolism of GBM compounds that may play a role in glomerular permeability, this lymphokine may have a potential pathogenic role in the proteinuria of IMLNS

Use of C4d as a diagnostic tool to classify membranoproliferative glomerulonephritis

Background: Membranoproliferative glomerulonephritis (MPGN type I, II and III) was reclassified in 2013 as MPGN and C3 glomerulopathy (C3G) based on the complement system activation mechanism. Objectives: To evaluate whether C4d, a component of the classical pathway, could be a diagnostic tool in differentiating between MPGN and C3G. Methods: We conducted a retrospective study of 15 MPGN type I, II and III and 13 minimal change disease (MCD) patients diagnosed between 2000 and 2012. C4d staining using the peroxidase method was employed. Results: Using the 2013 C3G consensus classification, the 15 MPGN types I, II and III biopsies were re-classified as MPGN (8) and C3G (7). Following C4d staining, of the 8 biopsies diagnosed as MPGN, 4 had classical pathway involvement [C1q (+), C3 (+), C4d (+)]; two had lectin pathway involvement [C1q (−), C3 (+), C4d (+)]; and, two were reclassified as C3G because the absence of C4d and C1q suggested the presence of the alternative pathway [C1q (−), C3 (+), C4d (−)]. Three of the seven C3G biopsies presented classical pathway involvement and were reclassified as MPGN. The alternative pathway was present in one of the other 4 biopsies considered to be C3G. Two C3G biopsies involved the lectin pathway and the one case of dense deposit disease had lectin pathway involvement. Conclusions: C4d staining may help to differentiate between MPGN and C3G. In addition, the lectin pathway could play a role in the pathogenesis of these glomerulopathies

BK viruria and viremia in children with systemic lupus erythematosus

Abstract Background BK virus (BKV) is a ubiquitous polyoma virus that lies dormant in the genitourinary tract once acquired in early childhood. In states of cellular immunodeficiency, the virus can reactivate to cause hemorrhagic cystitis and nephritis. Children with systemic lupus erythematosus (SLE) have an increased risk of developing infectious complications secondary to their immunocompromised state from the administration of several immuno-modulatory drugs. Currently, there are no data regarding the prevalence of BK viruria or viremia in children with SLE. Methods We conducted a prospective cohort study involving children with SLE of 18 years and younger. We obtained urine and blood samples at baseline and every 3 months up to 1 year for BK virus detection by real-time, quantitative polymerase chain reaction analysis. A comprehensive review of demographic information, clinical characteristics and medication history was also obtained. Results Thirty-two pediatric patients (26 females and 6 males) with SLE were enrolled. Median age at the time of SLE diagnosis and enrollment into study was 13.6 years and 16.0 years old, respectively. The prevalence at enrollment was 3.1% (1/32) for BK viruria and 6.2% (2/32) for BK viremia. During the study period, 3 patients had viruria, 5 had viremia and 4 had both viruria and viremia. Of the 12 patients with BKV reactivation, only one was positive for microscopic hematuria, all others were asymptomatic. A total of nine of 97(9.2%) urine samples and 10 of 96(10.4%) blood samples were positive for BK virus. The most commonly utilized biologics in this cohort group were Rituximab (90.6%), Abatacept (12.5%), and Belimumab (9.3%). The type of medication exposure and clinical characteristics did not statistically differ between the groups that did or did not have BK viruria and/or viremia. Conclusions Our study suggests that pediatric patients with SLE have BK viremia and/or viruria at a higher rate than the general healthy population, although the significance of the reactivation and viral level is unclear. The influence of immune-modulatory drugs on BKV reactivation is still uncertain. To understand the interplay amongst BK virus, immunosuppression and dysregulated immune system in children with SLE, ongoing research in a larger population is still warranted, which may help establish proper surveillance, diagnosis and treatment for BKV infection

Urinary CD80 Excretion Increases in Idiopathic Minimal-Change Disease

CD80 is expressed on all antigen-presenting cells and is present on podocytes in a number of experimental models of nephrotic syndrome. We tested whether urinary soluble CD80 increased with idiopathic minimal-change disease (MCD). We collected urine and serum samples from patients with MCD in relapse and in remission, patients with nephrotic syndrome resulting from other glomerular diseases (FSGS, membranoproliferative glomerulonephritis, IgA nephropathy, and membranous nephropathy), patients with systemic lupus erythematosus, and normal control subjects. Urinary concentrations of soluble CD80 in patients with relapsed MCD were significantly higher compared with those observed in patients with MCD in remission, other glomerular diseases, and systemic lupus erythematosus with and without proteinuria and healthy control subjects. Urinary concentrations of soluble CTLA-4, which is a negative regulator of CD80, were not statistically different in patients with relapsed MCD compared with those in remission. The urinary soluble CD80/CTLA-4 ratio was >100-fold higher in patients with relapsed MCD compared with those in remission (P < 0.008). In contrast, serum concentrations of soluble CD80 and CTLA-4 did not distinguish patients with MCD in relapse and in remission. In conclusion, urinary soluble CD80 is elevated in idiopathic MCD, which could be relevant to both diagnosis and pathogenesis

Angiopoietin-like-4 and minimal change disease

<div><p>Background</p><p>Minimal Change Disease (MCD) is the most common type of nephrotic syndrome in children. Angiopoietin-like-4 (Angplt4) has been proposed as mediator of proteinuria in MCD. The aim of this study was to evaluate the role of Angptl4 as a biomarker in MCD.</p><p>Methods</p><p>Patients with biopsy-proven primary MCD, focal segmental glomerulosclerosis, membranous nephropathy (60, 52 and 52 respectively) and 18 control subjects had urinary and serum Angptl4 measured by Elisa. Frozen kidney tissue sections were stained for Angptl4.</p><p>Results</p><p>Angptl4 was not identified in glomeruli of MCD patients in relapse. Urinary Angptl4 levels were elevated in MCD in relapse as well as in patients with massive proteinuria due to other glomerular diseases.</p><p>Conclusion</p><p>Neither serum nor urine Angptl4 appear to be good biomarkers in MCD. Elevated urinary Angptl4 n glomerular disease appears to reflect the degree of proteinuria rather than any specific disease.</p></div

Programa de Recepção e Integração do Intercambista - PRII

Background: Minimal change disease (MCD) is the most common cause of nephrotic syndrome in children and is associated with the expression of CD80 in podocytes and the increased excretion of CD80 in urine. We hypothesized that serum from patients with MCD might stimulate CD80 expression in cultured podocytes. Methods: Sera and peripheral blood mononuclear cells (PBMCs) were collected from subjects with MCD in relapse and remission and from normal controls. Immortalized human podocytes were incubated with culture media containing patient sera or supernatants from patient and control PBMC cultures. CD80 expression was measured by quantitative PCR and western blot analysis. Results: Sera collected from patients with MCD in relapse, but not in remission, significantly increased CD80 expression (mean ± standard deviation: 1.8 ± 0.7 vs. 0.8 ± 0.2; p < 0.004) and CD80 protein secretion by podocytes (p < 0.05 between relapse and normal controls). No such CD80 increase was observed when podocytes were incubated with supernatants of PBMC cultures from patients in relapse. Conclusions: Sera from MCD patients in relapse, but not in remission, stimulated CD80 expression in cultured podocytes. Identifying this factor in sera could provide insights into the pathogenesis of this disorder. No role in CD80 expression by podocytes was found for cytokines released by PBMCs. © 2013 IPNA.link_to_subscribed_fulltex

Urinary Angptl4 in MCD, FSGS, MN patients and control subjects.

<p>(A) Urinary Angptl4 in MCD, FSGS, MN patients and control subjects. (B) Urinary Angptl4 in FSGS and MN patients during relapse and remission. MCD minimal change disease, FSGS focal segmental glomerulosclerosis, MN membranous nephropathy, n refers to the number of patients, data expressed as mean±SD.</p