Anti-PAD4 autoantibodies in rheumatoid arthritis: levels in serum over time and impact on PAD4 activity as measured with a small synthetic substrate

Isoform 4 of the human peptidylarginine deiminase (hPAD4) enzyme may be responsible for the citrullination of antigens in rheumatoid arthritis (RA) and has been shown to be itself the target of disease-specific autoantibodies. Here, we have tested whether the level of serum anti-hPAD4 antibodies in RA patients is stable over a period of 10 years and whether the antibodies influence hPAD4-mediated deimination of the small substrate N-α-Benzoyl-l-arginine ethyl ester. RA sera (n = 128) obtained at baseline and after 10 years were assessed for anti-hPAD4 antibodies by a specific immunoassay. For 118 RA patients, serum anti-hPAD4 IgG levels were stable over 10 years. Seven patients who were negative for anti-PAD4 IgG at baseline had become positive after 10 years. Further, total IgG from selected RA patients and controls were purified, and a fraction was depleted for anti-hPAD4 antibodies. Kinetic deimination assays were performed with total IgG and depleted fractions. The k _cat and K _m values of hPAD4-mediated deimination of N-α-Benzoyl-l-arginine ethyl ester were not affected by the depletion of the anti-hPAD4 antibodies from the total IgG pool. In conclusion, RA patients remain positive for anti-hPAD4 antibodies over time and some patients who are initially anti-hPAD4 negative become positive later in the disease course. The anti-hPAD4 antibodies did not affect the enzymatic activity of hPAD4 when the small substrate N-α-Benzoyl-l-arginine ethyl ester was used. However, this finding may not exclude an effect of these autoantibodies on citrullination of protein substrates in RA.     

Guía clínica de la Asociación Europea de Urología sobre la evaluación y el tratamiento no quirúrgico de la incontinencia urinaria

ContextThe previous European Association of Urology (EAU) guidelines on urinary incontinence comprised a summary of sections of the 2009 International Consultation on Incontinence. A decision was made in 2010 to rewrite these guidelines based on an independent systematic review carried out by the EAU guidelines panel, using a sustainable methodology.ObjectiveWe present a short version of the full guidelines on assessment, diagnosis, and nonsurgical treatment of urinary incontinence, with the aim of increasing their dissemination.Evidence acquisitionEvidence appraisal included a pragmatic review of existing systematic reviews and independent new literature searches, based on Population, Intervention, Comparator, Outcome questions. Appraisal of papers was carried out by an international panel of experts, who also collaborated on a series of consensus discussions, to develop concise structured evidence summaries and action-based recommendations using a modified Oxford system.Evidence summaryThe full version of the guidelines is available online (http://www.uroweb.org/guidelines/online-guidelines/). The guidelines include algorithms that refer the reader back to the supporting evidence, and they are more immediately useable in daily clinical practice.ConclusionsThese new guidelines present an up-to-date summary of the available evidence, together with clear clinical algorithms and action-based recommendations based on the best available evidence. Where such evidence does not exist, they present a consensus of expert opinion.     

Mycophenolate Mofetil versus Cyclosporin A in Children with Frequently Relapsing Nephrotic Syndrome

The severe side effects of long-term corticosteroid or cyclosporin A (CsA) therapy complicate the treatment of children with frequently relapsing steroid-sensitive nephrotic syndrome (FR-SSNS). We conducted a randomized, multicenter, open-label, crossover study comparing the efficacy and safety of a 1-year treatment with mycophenolate mofetil (MMF; target plasma mycophenolic acid trough level of 1.5–2.5 µg/ml) or CsA (target trough level of 80–100 ng/ml) in 60 pediatric patients with FR-SSNS. We assessed the frequency of relapse as the primary endpoint and evaluated pharmacokinetic profiles (area under the curve [AUC]) after 3 and 6 months of treatment. More relapses per patient per year occurred with MMF than with CsA during the first year (P=0.03), but not during the second year (P=0.14). No relapses occurred in 85% of patients during CsA therapy and in 64% of patients during MMF therapy (P=0.06). However, the time without relapse was significantly longer with CsA than with MMF during the first year (P<0.05), but not during the second year (P=0.36). In post hoc analysis, patients with low mycophenolic acid exposure (AUC <50 µg⋅h/ml) experienced 1.4 relapses per year compared with 0.27 relapses per year in those with high exposure (AUC>50 µg⋅h/ml; P<0.05). There were no significant differences between groups with respect to BP, growth, lipid levels, or adverse events. However, cystatin clearance, estimated GFR, and hemoglobin levels increased significantly with MMF compared with CsA. These results indicate that MMF is inferior to CsA in preventing relapses in pediatric patients with FR-SSNS, but may be a less nephrotoxic treatment option.Idiopathic nephrotic syndrome, the most common form of childhood nephrotic syndrome, is most often associated with renal biopsy findings of minimal glomerular and tubulointerstitial changes (minimal change disease). Most patients respond to therapy with corticosteroids,¹ but about 70% experience a relapsing course.² Approximately 30% develop frequently relapsing steroid-sensitive nephrotic syndrome (FR-SSNS), defined as ≥4 relapses per year.³Although corticosteroids are the mainstay of therapy in pediatric patients with minimal change disease, their repeated use in FR-SSNS results in severe side effects, and other therapeutic options are needed to prevent steroid toxicity.⁴ A 2- to 3-month course of cyclophosphamide or chlorambucil has been shown to produce a longer remission period in many patients⁵; however, these drugs may have serious side effects and their long-term efficacy is limited.^6,7 Levamisole has been shown to reduce the risk of relapse in several small studies, but information is limited regarding long-term efficacy and adverse effects, and the drug is currently not available in most countries. Treatment with cyclosporin A (CsA) is highly effective in maintaining remission in patients with FR-SSNS allowing withdrawal of corticosteroids, but most patients relapse after withdrawal of CsA.⁸ Importantly, prolonged CsA therapy is accompanied by time- and dose-dependent nephrotoxicity.⁹Mycophenolate mofetil (MMF), the prodrug of mycophenolic acid (MPA), is a non-nephrotoxic immunosuppressive drug with inhibitory effects on T and B lymphocytes, cell-surface markers, and cytokine gene expression¹⁰ and has proven efficacy and tolerability in renal allograft recipients. Several small studies with limited statistical power have shown that MMF has steroid-sparing effects and reduces relapse rates in patients with FR-SSNS, albeit with varying efficacy.^11–18We studied efficacy and safety of MMF in patients with FR-SSNS in comparison with CsA in a prospective randomized multicenter open-label crossover trial.     

Febrile urinary tract infection after pediatric kidney transplantation: a multicenter,prospective observational study

Background

Febrile urinary tract infections (fUTIs) are common after kidney transplantation (KTx); however, prospective data in a multicenter pediatric cohort are lacking. We designed a prospective registry to record data on fUTI before and after pediatric KTx.

Methods

Ninety-eight children (58 boys and 40 girls)?≤?18 years from 14 mid-European centers received a kidney transplant and completed a 2-year follow-up.

Results

Posttransplant, 38.7 % of patients had at least one fUTI compared with 21.4 % before KTx (p?=?0.002). Before KTx, fUTI was more frequent in patients with congenital anomalies of kidneys and urinary tract (CAKUT) vs. patients without (38 % vs. 12 %; p?=?0.005). After KTx, fUTI were equally frequent in both groups (48.7 % vs. 32.2 %; p?=?0.14). First fUTI posttransplant occurred earlier in boys compared with girls: median range 4 vs. 13.5 years (p?=?0.002). Graft function worsened (p?<?0.001) during fUTI, but no difference was recorded after 2 years. At least one recurrence of fUTI was encountered in 58 %.

Conclusion

This prospective study confirms a high incidence of fUTI after pediatric KTx, which is not restricted to patients with CAKUT; fUTIs have a negative impact on graft function during the infectious episode but not on 2-year graft outcome.

     

Oncological,functional and perioperative outcomes in transplant patients after radical prostatectomy

Purpose

Oncological surgery in immunosuppressed patients with solid organ transplantation (Tx) is challenging. These patients are thought to have higher postoperative morbidity and an increased rate of tumour progression. The aim of the present study was to analyse oncological, functional and perioperative outcomes in Tx patients following radical prostatectomy (RP).

Materials and methods

Between 1996 and 2014, 30 patients diagnosed with prostate cancer underwent RP at our institution following Tx (kidney: n = 20, heart: n = 5, liver: n = 5). Functional, oncological and perioperative follow-ups were analysed. Postoperative complications were assessed using the Clavien–Dindo classification.

Results

Median follow-up was 45 months. Median PSA was 5.3 ng/ml. Intraoperative blood loss was 600 ml at a median operating time of 180 min. Surgery in kidney Tx patients was technically feasible. Major complications occurred in 3 patients (ureteral injury, lymphocele and haematoma). Histological evaluation revealed n = 18 ≤pT2 tumours (60.0 %), n = 7 pT3a tumours (23.3 %) and n = 5 ≥pT3b tumours (16.7 %). Continence rate 12 months after surgery, defined as no or one safety pad use, was 73.3 %, while 93.3 % of the patients used ≤2 pads/24 h. After the median follow-up of 45 months, BCR-free survival was 69.0 %. In recurrent men, there was suspicion of metastasis in one patient. No cancer-specific death was observed. Five-year overall survival was 94.4 %.

Conclusion

The complication rate in patients with solid organ transplantation after RP was low. While histopathological evaluation revealed disease characteristics comparable to non-transplant patients from current RP series, postoperative continence was worse. Immunosuppressive therapy does not seem to lead to an increased rate of tumour progression.

     

Mucosal challenge with cell-associated or cell-free feline immunodeficiency virus induces rapid and distinctly different patterns of phenotypic change in the mucosal and systemic immune systems

The majority of human immunodeficiency virus type 1 (HIV-1) infections occur via mucosal transmission through contact with genital secretions containing cell-associated and cell-free virus. However, few studies have assessed whether exposure to cells, HIV-1 infected or uninfected, plays a role in the sexual transmission of HIV-1. This study examined phenotypic changes in mucosal and systemic lymphoid tissue 24 hr after vaginal exposure to in vitro equilibrated infectious doses of cell-associated or cell-free feline immunodeficiency virus, uninfected heterologous cells, or medium alone. We found that even at this early time-point, mucosal exposure to virus induced substantial alterations in the phenotype and distribution of leucocytes, particularly in the tissues of the mucosal immune system. Second, we found that the type of virus inoculum directly influenced the phenotypic changes seen. Vaginal exposure to cell-free virus tended to induce more generalized phenotypic changes, typically in the peripheral immune system (blood and systemic lymph nodes). In contrast, exposure to cell-associated virus was primarily associated with phenotypic shifts in the mucosal immune system (gut and mucosal/draining lymph nodes). In addition, we found that exposure to uninfected heterologous cells also induced alterations in the mucosal immune system. These data suggest that significant immune changes occur within the first 24 hr of virus exposure, well before substantial replication would be anticipated. As the mucosal immune system, and particularly the gut, is an early and persistent target for lentiviral replication, these findings have substantial implications for HIV-1 pathogenesis and vaccine development.     

Reversible HLA multimers (Streptamers) for the isolation of human cytotoxic T lymphocytes functionally active against tumor- and virus-derived antigens

The development of MHC/peptide multimers has facilitated the visualization and purification of antigen-specific T cells. However, the persistence of multimers leads to prolonged T cell receptor signaling and subsequently to altered T-cell function. We have recently developed a new type of MHC/peptide multimers, which can be dissociated from the T cell. Herein, we have generated and tested for the first time reversible HLA/peptide multimers, termed Streptamers, for the isolation of human T cells. The Streptamer technique demonstrates the specificity and sensitivity of conventional HLA/peptide tetramers with regards to the sorting of human T lymphocytes. This is shown for T cells directed against immunogenic peptides derived from viral and tumor-associated antigens. We show that antigen-specific cytotoxic T cells remain functionally active following Streptamer dissociation, whereas lytic function and proliferation of the T cells is impaired in the presence of conventional tetramers. These novel HLA/peptide Streptamer reagents allow the isolation of antigen-specific T cells with preserved function and, therefore, facilitate the development of adoptive T cell transfer regimens for the treatment of patients with cancer or infectious diseases.