Intravenous Cyclophosphamide Therapy of Severe SLE

Three decades of progress in treating childhood-onset lupus nephritis

BACKGROUND AND OBJECTIVES

Childhood-onset lupus nephritis (LN) carries a worse renal prognosis compared with adults. Controlled treatment trials in children are lacking. We compared renal and patient survival in a cohort of pediatric patients followed over 3 decades.

DESIGN, SETTINGS, PARTICIPANTS, & MEASUREMENTS

A retrospective analysis was conducted on 138 patients with childhood-onset systemic lupus erythematosus from 1980 to 2010. The core cohort included 95 with severe LN: 28 progressed to end-stage renal disease (ESRD group) whereas 67 did not (no-ESRD group). Patients were stratified into four "eras" according to the introduction of the primary immuno-suppressive drug: era 1: triple oral therapy with corticosteroids (CS), cyclophosphamide (CYC), and azathioprine (AZA); era 2: intravenous CYC; era 3: mycophenolate mofetil (MMF) ± CYC; era 4: rituximab (RTX) ± CYC ± MMF.

RESULTS

Mean age at diagnosis was 12.3 ± 2.9 years with median follow-up of 5 years. Poor renal function (estimated GFR < 60 ml/min per 1.73 m(2)) and nephrotic proteinuria at diagnosis imparted a poor prognosis. Increasing proteinuria correlated with progression of kidney disease. The addition of MMF in era 3 improved 5-year renal survival from 52% to 91% and overall patient survival from 83% to 97%. African-American ethnicity was associated with significant risk for progression to ESRD whereas Hispanic ethnicity conferred an advantage. Infection and cardiovascular disease were the primary causes of patient demise.

CONCLUSIONS

Renal and patient survival in childhood-onset LN has improved during the past 3 decades with progressive treatment regimens. Future trials in children are very much warranted.

[Pathogenic basis of B cell targeted therapy in systemic lupus erythematosus (SLE)]

Recent success of B-cell targeted therapies in rheumatoid arthritis suggests their potential efficacy for other auntoantibody-mediated autoimmune diseases. Currently, multiple agents directed toward different B-cell specific targets are under development. Although the best strategy is yet to be defined, multiple functional inhibitors or cytolitic agents such as anti-CD20 or anti-CD19 are available. According to studies in RA, the most likely mechanism of action of rituximab (anti-CD20) consists of a secondary reduction in local (synovial) or systemic autoantibody producing short-lived plasma cells. According to this data, it is expected that these therapies will be efficacious in SLE, were B-cell enhanced function and autoantibodies play relevant pathogenetic roles. Clinical trials confirm B-cell effects, delayed activity on autoantibody synthesis, and most importantly, the feasibility of these therapies to treat SLE. However, there are no sufficient data confirming their therapeutic value when added to convencional therapy. Although multiple open trials suggest that rituximab might be useful for refractory manifestations of SLE, more controlled trials are needed in order to establish the indications and strategies of its use in SLE.

Pulse intravenous cyclophosphamide therapy for dermatologic disorders

Cyclophosphamide is a potent immunosuppressive agent that has an important role in the treatment of autoimmune, neoplastic, granulomatous, and neutrophilic disorders. Pulse intravenous cyclophosphamide has been shown to be efficacious for several dermatologic disorders, particularly pemphigus vulgaris, with a low incidence of toxicity reported. As reported earlier, studies performed on the use of pulse intravenous cyclophosphamide in the treatment of a variety of dermatology-related diseases strongly suggest that the toxicities frequently noted with the use of oral cyclophosphamide therapy may be significantly less common with pulse intravenous administration of cyclophosphamide. The short follow-up period of patients treated with this modality so far, however, requires constant vigilance for the development of side effects, particularly secondary malignancy. At this time, pulse intravenous cyclophosphamide is a promising treatment modality with an acceptable risk profile for moderate-to-severe dermatologic diseases recalcitrant to standard therapy. Prospective comparative trials are needed to assess further the efficacy and toxicity of this therapy.

Cyclophosphamide and other new agents for the treatment of severe aplastic anemia

Severe aplastic anemia (SAA) has a poor prognosis in the absence of treatment. Current accepted therapeutic strategies include allogeneic stem-cell transplantation and immunosuppression, both resulting in long-term survival in the majority of patients. Although human leukocyte antigen (HLA)-matched sibling stem-cell transplantation is highly effective, the 25% probability of finding a suitable sibling donor within a family renders this approach available to only a minority of patients. Transplantation using HLA-matched, unrelated donors carries a high risk of treatment failure along with considerable toxicity. While combined immunosuppression with both antithymocyte globulin (ATG) and cyclosporine A (CSA) produces hematologic improvement in most patients, relapse is common. Late evolution of aplastic anemia to other serious hematologic disorders, including paroxysmal nocturnal hemoglobinuria (PNH), myelodysplasia, and acute leukemia, is also a significant problem following treatment with ATG/CSA. Recently, results of immunosuppression in SAA with another potent immunosuppressive agent, cyclophosphamide, were reported in a small number of patients. The overall response rate was similar to that seen with ATG/CSA, but relapse and late clonal disease were not observed during a long period of follow-up. A larger randomized trial comparing sustained hematologic response rates to either conventional immunosuppression with ATG/CSA or high-dose cyclophosphamide and CSA is now underway; secondary end points include response duration, event-free survival, and overall survival. Additionally, a number of protocols designed to test the efficacy of alternative immunosuppressive or immunomodulatory agents are being developed.