Novel therapies of lupus nephritis

Endothelin-targeted new treatments for proteinuric and inflammatory glomerular diseases: focus on the added value to anti-renin-angiotensin system inhibition

Chronic kidney disease (CKD) is the main cause of end-stage renal disease worldwide arising as a frequent complication of diabetes, obesity, and hypertension. Current therapeutic options, mainly based of inhibition of the renin-angiotensin system (RAS), provide imperfect renoprotection if started at an advanced phase of the disease, and treatments that show or even reverse the progression of CKD are needed. The endothelin (ET) system contributes to the normal renal physiology; however, robust evidence suggests a key role of ET-1 and its cognate receptors, in the progression of CKD. The effectiveness of ET receptor antagonists in ameliorating renal hemodynamics and fibrosis has been largely demonstrated in different experimental models. A significant antiproteinuric effect of ET receptor antagonists has been found in diabetic and non-diabetic CKD patients even on top of RAS blockade, and emerging evidence from ongoing clinical trials highlights their beneficial effects on a wide range of kidney disorders.

Neonatal Fc receptor blockade by Fc engineering ameliorates arthritis in a murine model

Multiple autoimmune diseases are characterized by the involvement of autoreactive Abs in pathogenesis. Problems associated with existing therapeutics such as the delivery of intravenous immunoglobulin have led to interest in developing alternative approaches using recombinant or synthetic methods. Toward this aim, in the current study, we demonstrate that the use of Fc-engineered Abs (Abs that enhance IgG degradation [Abdegs]) to block neonatal FcR (FcRn) through high-affinity, Fc region binding is an effective strategy for the treatment of Ab-mediated disease. Specifically, Abdegs can be used at low, single doses to treat disease in the K/B×N serum transfer model of arthritis using BALB/c mice as recipients. Similar therapeutic effects are induced by 25- to 50-fold higher doses of i.v. Ig. Importantly, we show that FcRn blockade is a primary contributing factor toward the observed reduction in disease severity. The levels of albumin, which is also recycled by FcRn, are not affected by Abdeg delivery. Consequently, Abdegs do not alter FcRn expression levels or subcellular trafficking behavior. The engineering of Ab Fc regions to generate potent FcRn blockers therefore holds promise for the therapy of Ab-mediated autoimmunity.

Sterile empyematous pleural effusion in a patient with systemic lupus erythematosus: a diagnostic challenge

Herein we present a case of a patient with systemic lupus erythematosus (SLE) and a sterile empyematous pleural effusion, a complication not generally associated with SLE. A discussion of the diagnostic and treatment dilemmas follows the case presentation.

Rituximab and mycophenolate mofetil for relapsing proliferative lupus nephritis: a long-term prospective study

BACKGROUND

Subsequent to cyclophosphamide-based induction therapy of lupus nephritis, and despite maintenance chronic immunosuppressive treatment, many patients experience relapses.

METHODS

This prospective, observational study included 10 women with biopsy-proven relapse of proliferative lupus nephritis occurring during maintenance with mycophenolate mofetil (MMF) or azathioprine. The long-term outcome after a single course of the B-cell depleting anti-CD20 antibody rituximab (4 weekly infusions of 375 mg/m(2)), combined with daily MMF (2 g) and prednisolone (0.5 mg/ kg/day for 4 weeks, tapered thereafter) is presented.

RESULTS

While renal function was not severely impaired at baseline, partial remission (>50% improvement in all abnormal renal parameters) was achieved in eight patients at a median of 3.5 months. In seven patients, with 24-h urinary protein of 2.5 +/- 1.1 g (mean +/- SD), complete remission, associated with increases in serum complement levels and decreases in anti-dsDNA titres, was subsequently established (normal serum creatinine/albumin levels, inactive urine sediment and 24-h urinary protein <0.5 g). Complete nephritis remission was sustained at the follow-up end (median of 38 months) in six patients. Combination treatment was well tolerated.

CONCLUSIONS

The efficacy of this low-toxicity combination was particularly evident in patients with subnephrotic proteinuria due to proliferative lupus nephritis relapse. Controlled trials to define the role of rituximab/MMF in this condition are warranted.

Enzyme immunoassay for mycophenolic acid in milk and cheese

Mycophenolic acid (MPA) was reacted with N-hydroxysuccinimide and conjugated to keyhole limpet hemocyanin (KLH), and to horseradish peroxidase (HRP), respectively. The MPA-KLH was used to produce anti-MPA antiserum in rabbits. A competitive direct enzyme immunoassay (EIA) for MPA was established with anti-MPA antiserum and MPA-HRP conjugate. The mean 50% inhibition and detection limit of MPA standard curves (n = 103) were 197 +/- 67 and 81 +/- 48 pg/mL, respectively. The EIA was specific for MPA and its synthetic 2-morpholinoethyl ester, mycophenolate mofetil (91% relative cross-reactivity). Raw bulk milk and pasteurized milk, with and without beta-glucuronidase pretreatment, were analyzed by EIA. No MPA was found in milk, at a detection limit of 100 pg/mL (recovery 58-66% at 0.125-2 ng/mL). Blue-veined cheese from the German market (n = 53) was analyzed by EIA, and the detection limit was at 0.5 ng/g (recovery 68-79% at 5-100 ng/g). All but two cheeses contained MPA, although mostly (66%) at levels of <10 ng/g. MPA at 400-1200 ng/g was found in Roquefort cheeses. Highest levels (4-11 microg/g) were found in a German soft cheese preparation. MPA levels in mycelium-rich parts of cheese were 3 times higher than in mycelium-free parts.