Pieter van Paassen

Rituximab versus Cyclophosphamide in ANCA-Associated Renal Vasculitis

BACKGROUND Cyclophosphamide induction regimens for antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis are effective in 70 to 90% of patients, but they are associated with high rates of death and adverse events. Treatment with rituximab has led to remission rates of 80 to 90% among patients with refractory ANCA-associated vasculitis and may be safer than cyclophosphamide regimens. METHODS We compared rituximab with cyclophosphamide as induction therapy in ANCA-associated vasculitis. We randomly assigned, in a 3:1 ratio, 44 patients with newly diagnosed ANCA-associated vasculitis and renal involvement to a standard glucocorticoid regimen plus either rituximab at a dose of 375 mg per square meter of body-surface area per week for 4 weeks, with two intravenous cyclophosphamide pulses (33 patients, the rituximab group), or intravenous cyclophosphamide for 3 to 6 months followed by azathioprine (11 patients, the control group). Primary end points were sustained remission rates at 12 months and severe adverse events. RESULTS The median age was 68 years, and the glomerular filtration rate (GFR) was 18 ml per minute per 1.73 m(2) of body-surface area. A total of 25 patients in the rituximab group (76%) and 9 patients in the control group (82%) had a sustained remission (P=0.68). Severe adverse events occurred in 14 patients in the rituximab group (42%) and 4 patients in the control group (36%) (P=0.77). Six of the 33 patients in the rituximab group (18%) and 2 of the 11 patients in the control group (18%) died (P=1.00). The median increase in the GFR between 0 and 12 months was 19 ml per minute in the rituximab group and 15 ml per minute in the control group (P=0.14). CONCLUSIONS A rituximab-based regimen was not superior to standard intravenous cyclophosphamide for severe ANCA-associated vasculitis. Sustained-remission rates were high in both groups, and the rituximab-based regimen was not associated with reductions in early severe adverse events. (Funded by Cambridge University Hospitals National Health Service Foundation Trust and F. Hoffmann-La Roche; Current Controlled Trials number, ISRCTN28528813.)

Cardiac involvement in Churg‐Strauss syndrome

OBJECTIVE Churg-Strauss syndrome (CSS) is a rare form of systemic vasculitis. Previous studies showing cardiac involvement in CSS patients were limited in the number of patients and were often based solely on clinical manifestations. The aim of the present study was to determine in detail the incidence of cardiac involvement in a large population of ambulatory CSS patients. METHODS Thirty-two consecutive patients with CSS in remission (mean +/- SD duration of disease between diagnosis and enrollment 6.1 +/- 5.8 years, mean +/- SD age 61 +/- 10 years) who were previously unaware of cardiac involvement were compared with 32 randomly selected age- and sex-matched control subjects, using clinical evaluation, electrocardiography (EKG), echocardiography, and cardiac magnetic resonance imaging (MRI). RESULTS Detailed cardiac evaluation revealed a 62% prevalence of cardiac involvement in CSS patients compared with 3% in controls (P < 0.001), with clinical symptoms in 26% and 3%, respectively (P = 0.009), EKG abnormalities in 66% and 3%, respectively (P < 0.001), and echocardiographic defects in 50% and 3%, respectively (P < 0.001). Cardiac MRI detected cardiac manifestations in 62% of CSS patients. In the presence of cardiac MRI abnormalities, echocardiography could detect cardiac involvement with a sensitivity of 83% and a specificity of 80%. The absence of symptoms or EKG abnormalities did not exclude cardiac involvement, because abnormalities could still be detected in 38% of these patients at the time of echocardiography or cardiac MRI. CONCLUSION These results demonstrate a high incidence of cardiac involvement in CSS patients. Systematic cardiac evaluation including detailed imaging is required to properly identify CSS patients with cardiac involvement.

New pathophysiological insights and treatment of ANCA-associated vasculitis

ANCA-associated-vasculitis (AAV) comprises three different diseases entities: Churg-Strauss syndrome, microscopic polyangiitis, and Wegeners granulomatosis. AAV is an autoimmune disease with complex pathophysiology. Anti-neutrophil cytoplasmic antibodies (ANCAs) with specificity for proteinase-3 (PR3) or myeloperoxidase (MPO) are hallmarks of AAV and have a pivotal role in disease development. In addition to ANCA, the cellular immune system contributes to the pathogenesis of the disease. ANCA-mediated degranulation of neutrophils causes vasculitic damage; T cells drive granuloma formation, promote vasculitic damage by several different pathways, and enhance autoantibody production by B cells. Recently, complementary PR3 and lysosomal membrane protein-2 were suggested as novel autoantigens in AAV. New findings also indicate the importance of complement, danger-associated molecular patterns, and dendritic cells in AAV. This review highlights novel pathophysiological findings in AAV and puts them into context with the current understanding of disease mechanisms. Furthermore, implications for present and new therapeutic strategies are discussed.

ANCA as a Predictor of Relapse: Useful in Patients with Renal Involvement But Not in Patients with Nonrenal Disease

The value of measuring ANCA during follow-up to predict a relapse is controversial. On the basis of recently obtained pathophysiologic insights, we postulated that measuring ANCA is useful in patients with renal involvement but is less valuable in patients with nonrenal disease. One hundred sixty-six consecutive patients with ANCA-associated vasculitis, positive for either proteinase 3 (PR3)-ANCA or myeloperoxidase (MPO)-ANCA, were included in our study, followed at regular intervals, and tested for PR3-ANCA and MPO-ANCA. In this cohort, 104 patients had renal involvement (72 with PR3-ANCA, 32 with MPO-ANCA) and 62 patients had nonrenal disease (36 with PR3-ANCA, 26 with MPO-ANCA). During an average (±SD) follow-up of 49±33 months and 18±14 ANCA measurements, 89 ANCA rises and 74 relapses were recorded. ANCA rises correlated with relapses in patients who presented with renal involvement (hazard ratio [HR], 11.09; 95% confidence interval [95% CI], 5.01 to 24.55), but in comparison, associated only weakly with relapses in patients who presented with nonrenal disease (HR, 2.79; 95% CI, 1.30 to 5.98). In conclusion, longitudinal ANCA measurements may be useful in patients with renal involvement but is less valuable in patients with nonrenal disease.

Rituximab versus cyclophosphamide in ANCA-associated renal vasculitis: 2-year results of a randomised trial

OBJECTIVES The RITUXVAS trial reported similar remission induction rates and safety between rituximab and cyclophosphamide based regimens for antineutrophil cytoplasm antibody (ANCA)-associated vasculitis at 12 months; however, immunosuppression maintenance requirements and longer-term outcomes after rituximab in ANCA-associated renal vasculitis are unknown. METHODS Forty-four patients with newly diagnosed ANCA-associated vasculitis and renal involvement were randomised, 3:1, to glucocorticoids plus either rituximab (375 mg/m(2)/week×4) with two intravenous cyclophosphamide pulses (n=33, rituximab group), or intravenous cyclophosphamide for 3-6 months followed by azathioprine (n=11, control group). RESULTS The primary end point at 24 months was a composite of death, end-stage renal disease and relapse, which occurred in 14/33 in the rituximab group (42%) and 4/11 in the control group (36%) (p=1.00). After remission induction treatment all patients in the rituximab group achieved complete B cell depletion and during subsequent follow-up, 23/33 (70%) had B cell return. Relapses occurred in seven in the rituximab group (21%) and two in the control group (18%) (p=1.00). All relapses in the rituximab group occurred after B cell return. CONCLUSIONS At 24 months, rates of the composite outcome of death, end-stage renal disease and relapse did not differ between groups. In the rituximab group, B cell return was associated with relapse. TRIAL REGISTRATION NUMBER ISRCTN28528813.

Does the Renin-Angiotensin System Determine the Renal and Systemic Hemodynamic Response to Sodium in Patients With Essential Hypertension?

Many patients with essential hypertension respond to a high dietary sodium intake with a rise in blood pressure. Experimental evidence suggests that the renal hemodynamic response to sodium determines, at least partially, this rise in blood pressure. Our aim was to clarify the role of the renin-angiotensin system in the renal and systemic adaptation to a change in dietary sodium. We studied changes in mean arterial pressure (MAP) (millimeters of mercury), effective renal plasma flow (ERPF), body weight, and immunoreactive renin in 17 patients with essential hypertension and 15 normotensive control subjects, randomly crossing over between a 3-week sodium-restricted (50 mmol/24 h) and a sodium-replete (200 mmol/24 h) diet period. In addition, the effects of renin inhibition by remikiren (600 mg, single oral dose) were studied during the high sodium period. In normotensive control subjects, high sodium intake had no effect on MAP or body weight, whereas ERPF increased (490 +/- 19 to 535 +/- 21 mL/min, P < .05) and immunoreactive renin decreased (32 +/- 6 to 14 +/- 1 pg/mL). In hypertensive subjects, high sodium intake induced a heterogeneous response of MAP (median change, 2.6 mm Hg; range, -4.7 to +21.2; P = NS) and ERPF (median change, 21 mL/min; range, -33 to +98; P = NS). Body weight increased from 81.3 +/- 1.9 to 82.5 +/- 2.0 kg (P < .05), and immunoreactive renin decreased from 18 +/- 3 to 10 +/- 1 pg/mL (P < .05). Interestingly, the patients with a distinct rise in MAP showed a blunted ERPF response to high sodium intake (r = -.70, P < .01) and an increase in body weight (r = .76, P < .001). Moreover, the increase of ERPF was more pronounced in patients with a larger fall in immunoreactive renin (r = .77, P < .001). After administration of remikiren, a heterogeneous response in ERPF was observed: the patients with the blunted ERPF response to high sodium intake showed the largest ERPF rise (r = .70, P < .01). The remikiren-induced rise in ERPF correlated (r = .68, P < .01) with the fall in MAP (114 +/- 2 to 110 +/- 2 mm Hg). In conclusion, in patients with essential hypertension a rise in blood pressure in response to high sodium intake appears to partially be the result of insufficient renal vasodilatation. This seems to be due to an inadequate (intrarenal?) renin-angiotensin system response to increased sodium intake.

Improved outcome in anti-neutrophil cytoplasmic antibody (ANCA)-associated glomerulonephritis: a 30-year follow-up study

BACKGROUND Anti-neutrophil cytoplasmic antibody (ANCA)-associated glomerulonephritis has a poor prognosis. In the current study, we assessed whether prognosis in these patients improved over the last three decades. METHODS In a large inception cohort, all consecutive patients with ANCA-associated glomerulonephritis were included between January 1979 and December 2009. Inclusion criteria were the presence of ANCA and the availability of a kidney biopsy. To assess renal and patient survival, patients were divided in three groups through time: 1979-89, 1990-2000 and 2001-09. RESULTS A total of 181 patients were included. One-, 5- and 10-year survival was 77, 66 and 49%, respectively. Survival within the time groups was significantly different, yielding a hazard ratio for death of 2.9 for 1990-2000 and 3.9 for 1979-89 compared with 2001-09 (P < 0.001). Serum creatinine and active lesions as found in the kidney biopsy significantly decreased through the three decades. CONCLUSIONS Both patient and renal survival in patients with ANCA-associated renal vasculitis have improved over the last three decades. We postulate that both earlier diagnosis and better therapeutic management of patients are responsible for this effect.

T cells in ANCA-associated vasculitis: what can we learn from lesional versus circulating T cells?

Anti-neutrophil cytoplasmic antibody (ANCA) - associated vasculitis (AAV) is a life-threatening autoimmune disease characterized by an antibody-mediated glomerulonephritis and necrotizing vasculitis. Apart from antibodies, T cells are also involved in disease pathogenesis. This review stresses the hallmarks of T cell-mediated pathology in AAV and highlights the characteristics of lesional and circulating T cells in the immune response in AAV. Circulating effector T-cell populations are expanded and are in a persistent state of activation. Circulating regulatory T-cell subsets are less well characterized but seem to be impaired in function. Lesional effector T cells are present in granulomas, vasculitic lesions, and nephritis. Lesional T cells usually show pro-inflammatory properties and promote granuloma formation. Apart from T cells, dendritic cells are abundantly present at the sites of inflammation and locally orchestrate the immune response. Targeting the above-mentioned T cell-mediated disease mechanisms will potentially provide powerful therapeutic tools for AAV.

Intravenous immunoglobulin therapy for patients with idiopathic cardiomyopathy and endomyocardial biopsy-proven high PVB19 viral load.

BACKGROUND Parvovirus B19 (PVB19) persistence in the heart has been associated with progressive cardiac dysfunction and evolution to dilated cardiomyopathy. In the present study, we investigated whether immunomodulation with intravenous immunoglobulin (IVIg) in addition to conventional heart failure therapy is safe and achieves virus reduction. Such therapy might improve cardiac function in patients with chronic dilated cardiomyopathy (DCM) and a significant PVB19 viral load in the heart. METHODS PVB19 viral load was studied in 25 post-mortem cardiac samples of patients with a normal heart. Then, 17 consecutive patients (mean age 53 +/-3 years) with DCM and symptomatic heart failure for >1 year with a PVB19 viral load in endomyocardial biopsies of >250 copies/microg DNA were treated with a high dose of IVIg (2 g/kg). RESULTS The post-mortem cardiac samples revealed a PVB19 presence in 80% with a mean load of 131 +/-40 copies/microg DNA. In the treated patients, IVIg resulted in a significant decrease of PVB19 viral load from 1,420 +/-216 to 619 +/-200 copies/microg DNA (P=0.004) and significantly improved the ejection fraction from 33 +/-3% 6 months before treatment and 34 +/-3% at baseline to 41 +/-3% 6 months (P=0.001) after IVIg therapy. The New York Heart Association classification significantly improved from 2.5 +/-0.1 at baseline to 2.1 +/-0.1 at follow-up (P=0.004). No therapy-related complications were noted. CONCLUSIONS The present pilot study demonstrates that IVIg significantly reduces viral load and improves cardiac function in patients with DCM related to increased PVB19 viral load in the heart.

Estimating Renal Survival Using the ANCA-Associated GN Classification

A histopathological classification system for ANCA-associated vasculitis was recently published, but whether this system predicts renal outcome requires validation. Here, we analyzed data from 164 consecutive patients with biopsy-proven renal involvement of ANCA-associated vasculitis. The ANCA-associated GN (AGN) classification categorizes patients as having focal, mixed, crescentic, or sclerotic GN. Five-year renal survival rates by categories of the AGN classification scheme were 91% for focal, 69% for mixed, and 64% for crescentic (log-rank P<0.0001). Only one patient was classified as sclerotic. Furthermore, the percentage of normal glomeruli found on biopsy estimated renal survival with the same precision as did the AGN classification scheme. Patients classified as crescentic or mixed, however, had worse survival when the percentage of normal glomeruli was <25%. In conclusion, the AGN classification for renal biopsy specimens is a practical and informative scheme with which to categorize patients with ANCA-associated vasculitis, but adding the percentage of normal glomeruli to the system seems to improve its predictive value.