Alexandre Karras

Rituximab combined with Peg-interferon-ribavirin in refractory hepatitis C virus-associated cryoglobulinaemia vasculitis

Objectives: To report the results of a pilot study using rituximab combined with Peg-interferon (IFN) α2b-ribavirin in severe refractory hepatitis C virus (HCV) related mixed cryoglobulinaemia (MC) vasculitis. Methods: Sixteen consecutive patients with severe HCV-MC vasculitis that were resistant (nu200a=u200a11) or relapser (nu200a=u200a5) to a previous combination treatment with standard (nu200a=u200a10) or Peg-IFNα2b (nu200a=u200a6) plus ribavirin were included. They were treated with rituximab (375 mg/m2 intravenously weekly for 4 weeks) combined with Peg-IFNα2b (1.5 μg/kg per week subcutaneously) plus ribavirin (600–1200 mg/day orally) for 12 months. Results: Fifteen patients (93.7%) showed clinical improvement, 10 of whom (62.5%) were clinical complete responders (CR). HCV RNA and serum cryoglobulin became undetectable in all the clinical CR. Peripheral blood B cell depletion was achieved in all patients (CD19+ cells, 111 (SD 32)/mm3 at baseline versus 2(2)/mm3 after the fourth infusion of rituximab) with reconstitution starting at the end of antiviral treatment. Compared with clinical CR, the partial or non-responders had a 3.6 times longer duration of vasculitis prior to treatment and a lower rate of early virological response. Treatment was well tolerated with no infectious complications. After a mean follow-up of 19.4 (SD 3.6) months, two patients experienced clinical relapse associated with a simultaneous reappearance of HCV RNA and cryoglobulin and an increase in the number of B cells. Conclusions: Rituximab combined with Peg-IFNα2b-ribavirin represents a safe and effective treatment option in severe refractory HCV-MC vasculitis.

Excessive interleukin‐15 transpresentation endows NKG2D+CD4+ T cells with innate‐like capacity to lyse vascular endothelium in granulomatosis with polyangiitis (Wegener's)

OBJECTIVEnGranulomatosis with polyangiitis (Wegeners) (GPA) is a rare systemic vasculitis of unknown etiology. Contribution of T cell-mediated immunity is suggested by the presence of granulomatous inflammation and T cell infiltrates in different tissues. We undertook this study to determine whether CD4+ T cells aberrantly expressing the NKG2D activating receptor might participate in the pathophysiology of the disease.nnnMETHODSnWe performed a detailed phenotype and functional analysis of CD4+ T cells in a cohort of 90 GPA patients (37 with localized GPA and 53 with generalized GPA) in comparison with 39 age-matched controls.nnnRESULTSnWe observed circulating innate-like CD4+ T cells expressing an assortment of activating natural killer (NK) cell receptors (NKG2D, 2B4, DNAX-associated molecule 1, and some killer cell Ig-like receptors) and their signaling partners. Expansions of NKG2D+CD4+ T cells greater than a critical threshold of 3% yielded 100% specificity for generalized vasculitis versus localized granulomatosis, suggesting their participation in endothelium damage. Excessive interleukin-15 (IL-15) transpresentation through increased expression of IL-15 receptor α (IL-15Rα), together with abnormal expression of major histocompatibility complex (MHC) class I chain-related A protein on monocyte/macrophages, induced abnormal expansion of NKG2D+CD4+ T cells. These cells were primed in vivo to exert direct, MHC-independent cytotoxicity toward microvascular endothelial cells expressing the cognate ligands of NK cell receptors.nnnCONCLUSIONnOur results suggest that NK cell-like CD4+ T cells might be the driving force of the vasculitis in GPA, and point to IL-15 as an important mediator in the progression of GPA toward generalized vasculitis. IL-15/IL-15Rα antagonists may thus become novel therapeutic tools to decrease the pool of NK cell receptor-positive CD4+ T cells in selected GPA patients.

Long-term Kidney Disease Outcomes in Fibrillary Glomerulonephritis: A Case Series of 27 Patients

BACKGROUNDnFibrillary glomerulonephritis (GN) is a rare disorder with poor renal prognosis. Therapeutic strategies, particularly the use of immunosuppressive drugs, are debated.nnnSTUDY DESIGNnCase series.nnnSETTING & PARTICIPANTSn27 adults with fibrillary GN referred to 15 nephrology departments in France between 1990 and 2011 were included. All patients were given renin-angiotensin system blockers and 13 received immunosuppressive therapy, including rituximab (7 patients) and cyclophosphamide (3 patients).nnnOUTCOMES & MEASUREMENTSnClinical and histologic features of patients and kidney disease outcome. Renal response was defined as a >50% decrease in 24-hour proteinuria with <15% decline in estimated glomerular filtration rate (eGFR).nnnRESULTSnAll patients presented with proteinuria, associated with nephrotic syndrome (41%), hematuria (73%), and hypertension (70%). Baseline median eGFR was 49 mL/min/1.73 m(2). Eight patients had a history of autoimmune disease and none had evidence of hematologic malignancy during follow-up. Light microscopic studies showed mesangial GN (70%), predominant pattern of membranous GN (19%), or membranoproliferative GN (11%). By immunofluorescence, immunoglobulin G (IgG) deposits (IgG4, 15/15; IgG1, 9/15) were polyclonal in 25 cases. Serum IgG subclass distribution was normal in the 6 patients tested. After a median 46-month follow-up, renal response occurred in 6 of 13 patients who received immunosuppressive therapy with rituximab (5 patients) or cyclophosphamide (1 patient). Of these, 5 had a mesangial or membranous light microscopic pattern, and median eGFR before therapy was 76 mL/min/1.73 m(2). In contrast, chronic kidney disease progressed in 12 of 14 patients who were not given immunosuppressive therapy, 10 of whom reached end-stage renal disease.nnnLIMITATIONSnNumber of patients, retrospective study, use of multiple immunosuppressive regimens.nnnCONCLUSIONSnThe therapeutic approach in fibrillary GN remains challenging. The place of immunosuppressive therapy, particularly anti-B-cell agents, needs to be assessed in larger collaborative studies.

Presentation and prognosis of cardiac involvement in hepatitis C virus-related vasculitis.

Cardiac manifestation in primary systemic vasculitides is associated with poor outcomes, leading to the use of immunosuppressive therapy. In contrast, the spectrum and the outcome of cardiac involvement in the setting of mixed cryoglobulinemia vasculitis (CryoVas) have never been evaluated. To describe the clinical presentation and to evaluate clinical outcomes of cardiac manifestations during hepatitis C virus (HCV)-related mixed CryoVas, the clinical records of 165 consecutive patients with HCV-related mixed CryoVas followed from January 1, 1993, to January 1, 2010, were reviewed. Of the 165 patients with HCV-related mixed CryoVas, 7 (4%) had cardiac manifestations. Thoracic pain and congestive heart failure manifestations were the main clinical manifestations (nxa0= 4 [57%] each). Cardiac imaging showed dilated cardiomyopathy in 5 patients and hypertrophic cardiomyopathy in 1. In multivariate analysis, patients with cardiac manifestations had more frequent B-cell lymphoma (odds ratio 18.1, 95% confidence interval 2.8 to 116.7, pxa0= 0.0023) and gastrointestinal involvement (odds ratio 14.6, 95% confidence interval 2.0 to 104.9, pxa0= 0.0078). All cardiac manifestations were reversible early after the initiation of corticosteroids and aggressive immunosuppressive therapy. However, after a median follow-up period of 19 months, 3 patients (43%) had died. Respective 6-month, 1-year, and 2-year survival rates in patients with and without cardiac involvement were 86% and 99%, 71% and 96%, and 48% and 90% (hazard ratio 5.01, pxa0= 0.003). In conclusion, cardiac damage is a rare manifestation of HCV-related mixed cryoglobulinemia vasculitis. Cardiac involvement is associated with B-cell lymphoma and life-threatening manifestations. Despite favorable early outcomes, patients with cardiac damage had poorer survival than those without.

Randomised controlled trial of prolonged treatment in the remission phase of ANCA-associated vasculitis

Objectives A prospective randomised trial to compare two different durations of maintenance immunosuppressive therapy for the prevention of relapse in anti-neutrophil cytoplasmic antibodies (ANCA)-associated vasculitis (AAV). Methods Patients with AAV were recruited 18–24 months after diagnosis if they were in stable remission after cyclophosphamide/prednisolone-based induction followed by azathioprine/prednisolone maintenance therapy. They were randomised (1:1) to receive continued azathioprine/prednisolone to 48 months from diagnosis (continuation group) or to withdraw azathioprine/prednisolone by 24 months (withdrawal group). The primary endpoint was the relapse risk, from randomisation to 48 months from diagnosis. Results One hundred and seventeen patients were randomised and 110 remained to the trial end. At entry, median serum creatinine was 116 μmol/L (range 58–372), 53% were ANCA positive. The percentage of patients presenting with relapse was higher in the withdrawal than in the continuation treatment group (63% vs 22%, p<0.0001, OR 5.96, 95%u2009CI 2.58 to 13.77). ANCA positivity at randomisation was associated with relapse risk (51% vs 29%, p=0.017, OR 2.57, 95%u2009CI 1.16 to 5.68). Renal function, ANCA specificity, vasculitis type and age were not predictive of relapse. Severe adverse events were more frequent in the continuation than withdrawal groups (nine vs three events), but the continuation group had better renal outcome (0 vs 4 cases of end-stage renal disease), with no difference in patient survival. Conclusions Prolonged remission maintenance therapy with azathioprine/prednisolone, beyond 24 months after diagnosis reduces relapse risk out to 48 months and improves renal survival in AAV. Trial registration number ISRCTN13739474

High prevalence of and potential mechanisms for chronic kidney disease in patients with acute intermittent porphyria

Acute intermittent porphyria (AIP) is a genetic disorder of the synthesis of heme caused by a deficiency in hydroxymethylbilane synthase (HMBS), leading to the overproduction of the porphyrin precursors δ-aminolevulinic acid and porphobilinogen. The aim of this study is to describe the clinical and biological characteristics, the renal pathology, and the cellular mechanisms of chronic kidney disease associated with AIP. A total of 415 patients with HMBS deficiency followed up in the French Porphyria Center were enrolled in 2003 in a population-based study. A follow-up study was conducted in 2013, assessing patients for clinical, biological, and histological parameters. In vitro models were used to determine whether porphyrin precursors promote tubular and endothelial cytotoxicity. Chronic kidney disease occurred in up to 59% of the symptomatic AIP patients, with a decline in the glomerular filtration rate of ~1u2009ml/min per 1.73u2009m(2) annually. Proteinuria was absent in the vast majority of the cases. The renal pathology was a chronic tubulointerstitial nephropathy, associated with a fibrous intimal hyperplasia and focal cortical atrophy. Our experimental data provide evidence that porphyrin precursors promote endoplasmic reticulum stress, apoptosis, and epithelial phenotypic changes in proximal tubular cells. In conclusion, the diagnosis of chronic kidney disease associated with AIP should be considered in cases of chronic tubulointerstitial nephropathy and/or focal cortical atrophy with severe proliferative arteriosclerosis.

Urinary Retinol Binding Protein Is a Marker of the Extent of Interstitial Kidney Fibrosis

Currently, a non-invasive method to estimate the degree of interstitial fibrosis (IF) in chronic kidney disease is not available in routine. The aim of our study was to evaluate the diagnostic performance of the measurement of urinary low molecular weight (LMW) protein concentrations as a method to determine the extent of IF. The urines specimen from 162 consecutive patients who underwent renal biopsy were used in the analysis. Numerical quantification software based on the colorimetric analysis of fibrous areas was used to assess the percentage IF. Total proteinuria, albuminuria, and the urinary levels of retinol binding protein (RBP), alpha1-microglobulin (α1MG), beta 2-microglobulin (β2MG), transferrin, and IgG immunoglobulins were measured. There was a significant correlation between the degree of IF and the RBP/creatinine (creat) ratio (R2: 0.11, p<0.0001). IF was associated to a lesser extent with urinary β2MG and α1MG; however, there was no association with total proteinuria or high molecular weight (HMW) proteinuria. The correlation between IF and RBP/creat remained significant after adjustment to the estimated glomerular filtration rate, age, body mass index, α1MG, and β2MG. The specificity of the test for diagnosing a fibrosis score of >25% of the parenchyma was 95% when using a threshold of 20 mg/g creat. In conclusion, RBP appears to be a quantitative and non-invasive marker for the independent prediction of the extent of kidney IF. Because methods for the measurement of urinary RBP are available in most clinical chemistry departments, RBP measurement is appealing for implementation in the routine care of patients with chronic kidney disease.

Thrombotic Microangiopathy and Purtscher-Like Retinopathy Associated With Adult-Onset Still's Disease: A Role for Glomerular Vascular Endothelial Growth Factor?

Adult-onset Still’s disease (AOSD) is a rare systemic in-flammatory disorder of unknown etiology. It is character-ized by daily high spiking fevers associated with an eva-nescent rash, arthritis, and multiorgan involvement (1,2).HerewereportapatientwithAOSD-associatedthromboticmicroangiopathy (TMA) combining central nervous sys-tem and renal involvement, associated with 2 severe andunusual complications: Purtscher-like retinopathy and ex-tremity gangrene. Interestingly, renal biopsy showed de-creased expression of glomerular vascular endothelialgrowth factor (VEGF), which could have triggered theTMA and may represent a new pathophysiologic mecha-nism in human TMA.

Performance of GFR Estimating Equations in African Europeans: Basis for a Lower Race-Ethnicity Factor Than in African Americans

References 1. Fuller DS, Pisoni RL, Bieber BA, Gillespie BW, Robinson BM. The DOPPS Practice Monitor for US dialysis care: trends through December 2011. Am J Kidney Dis. 2013;61(2):342-348. 2. Twentieth Annual Report 2011. Creutzfeldt-Jakob disease surveillance in the UK. The National CJD Research & Surveillance Unit, Western General Hospital, Edinburgh, EH4 2XU. http://www.cjd.ed.ac.uk/documents/report20.pdf. Accessed January 3, 2013.

Tissue-Specific Microvascular Endothelial Cells Show Distinct Capacity To Activate NK Cells: Implications for the Pathophysiology of Granulomatosis with Polyangiitis

The relevance of tissue specificity of microvascular endothelial cells (MECs) in the response to inflammatory stimuli and sensitivity to immune cell–mediated injury is not well defined. We hypothesized that such MEC characteristics might shape their interaction with NK cells through the use of different adhesion molecules and NK cell receptor ligands or the release of different soluble factors and render them more or less vulnerable to NK cell injury during autoimmune vasculitis, such as granulomatosis with polyangiitis (GPA). To generate a comprehensive expression profile of human MECs of renal, lung, and dermal tissue origin, we characterized, in detail, their response to inflammatory cytokines and to proteinase 3, a major autoantigen in GPA, and analyzed the effects on NK cell activation. In this study, we show that renal MECs were more susceptible than lung and dermal MECs to the effect of inflammatory signals, showing upregulation of ICAM-1 and VCAM-1 on their surface, as well as release of CCL2, soluble fractalkine, and soluble VCAM-1. Proteinase 3–stimulated renal and lung MECs triggered CD107a degranulation in control NK cell. Notably, NK cells from GPA patients expressed markers of recent in vivo activation (CD69, CD107a), degranulated more efficiently than did control NK cells in the presence of renal MECs, and induced direct killing of renal MECs in vitro. These results suggest that, upon inflammatory conditions in GPA, renal MECs may contribute to the recruitment and activation of NK cells in the target vessel wall, which may participate in the necrotizing vasculitis of the kidney during this disease.