John H. Klippel

We evaluated renal function in 107 patients with active lupus nephritis who participated in long-term randomized therapeutic trials (median follow-up, seven years). For patients taking oral prednisone alone, the probability of renal failure began to increase substantially after five years of observation. Renal function was better preserved in patients who received various cytotoxic-drug therapies, but the difference was statistically significant only for intravenous cyclophosphamide plus low-dose prednisone as compared with high-dose prednisone alone (P = 0.027). The advantage of treatment with intravenous cyclophosphamide over oral prednisone alone was particularly apparent in the high-risk subgroup of patients who had chronic histologic changes on renal biopsy at study entry. Patients treated with intravenous cyclophosphamide have not experienced hemorrhagic cystitis, cancer, or a disproportionate number of major infections. We conclude that, as compared with high-dose oral prednisone alone, treatment of lupus glomerulonephritis with intravenous cyclophosphamide reduces the risk of end-stage renal failure with few serious complications.

BACKGROUND: Controlled trials in lupus nephritis have demonstrated that cyclophosphamide therapy is superior to corticosteroid therapy alone. The long-term effectiveness and side-effect profiles of pulse immunosuppressive regimens warrant further study. OBJECTIVE: To define the long-term risk and benefit of monthly treatment with boluses of methylprednisolone, cyclophosphamide, or both. DESIGN: Extended follow-up (median, 11 years) of a randomized, controlled trial. SETTING: U.S. government research hospital. PATIENTS: 82 patients with proliferative lupus nephritis. MEASUREMENTS: Rates of treatment failure (defined as need for supplemental immunosuppressive therapy or doubling of serum creatinine concentration, or death) and adverse events. RESULTS: In an intention-to-treat survival analysis, the likelihood of treatment failure was significantly lower in the cyclophosphamide (P = 0.04) and combination therapy (P = 0.002) groups than in the methylprednisolone group. Combination therapy and cyclophosphamide therapy alone did not differ statistically in terms of effectiveness or adverse events. Of patients who completed the protocol (n = 65), the proportion of patients who had doubling of serum creatinine concentration was significantly lower in the combination group than in the cyclophosphamide group (relative risk, 0.095 [95% CI, 0.01 to 0.842]). CONCLUSION: With extended follow-up, pulse cyclophosphamide continued to show superior efficacy over pulse methylprednisolone alone for treatment of lupus nephritis. The combination of pulse cyclophosphamide and methylprednisolone appears to provide additional benefit over pulse cyclophosphamide alone and does not confer additional risk for adverse events.

A previously undescribed species of human leukocyte, or alpha, interferon is present in the serum of many patients with systemic lupus erythematosus. It was shown to be alpha-interferon by neutralization with specific antiserums, affinity column chromatography, and antiviral activity on bovine cells. However, 23 of 30 interferon samples tested were inactivated by incubation at pH 2, a characteristic of human "immune," or gamma, interferon. Multiple samples of interferon from the same patient had similar biological properties, but samples from different patients were not all identical, suggesting that several variants of this species of human alpha-interferon may exist.