Objectives The objectives of this study are to analyse the long-term follow-up of a randomised controlled trial of induction treatment with azathioprine/methylprednisolone (AZA/MP) versus high-dose intravenous cyclophosphamide (ivCY) in patients with proliferative lupus nephritis (LN) and to evaluate the predictive value of clinical, laboratory and renal biopsy parameters regarding renal outcome.
Methods 87 patients with biopsy-proven proliferative LN were treated with either AZA/MP (n=37) or ivCY (n=50), both with oral prednisone. After 2 years, renal biopsy was repeated, and all patients continued with AZA/oral prednisone. The primary study end point was sustained doubling of serum creatinine. Secondary end points included renal relapse, end-stage renal disease and mortality.
Results After a median follow-up of 9.6 years, no significant differences between AZA/MP versus ivCY groups were found in the proportion of patients with sustained doubling of serum creatinine (n=6 (16%) vs n=4 (8%); p=0.313), end-stage renal disease (n=2 (5%) vs n=2 (4%); p=1.000) or mortality (n=6 (16%) vs n=5 (10%); p=0.388). Renal relapses occurred more often in the AZA/MP group (n=14 (38%) vs n=5 (10%); p=0.002, HR: 4.5). Serum creatinine, proteinuria and immunosuppressive treatment regimens at the last follow-up were comparable. Clinical and laboratory parameters at baseline and after 2 years, and renal biopsy parameters (only) at baseline predicted renal outcome.
Conclusion Induction treatment with ivCY was superior to AZA/MP in preventing renal relapses, but other parameters for renal function did not differ. AZA/MP can therefore serve as an alternative in patients with proliferative LN who wish to avoid gonadal toxicity of CY. Several prognostic factors of long-term renal outcome were identified.
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Contributors SA contributed to the analysis and interpretation of data and to the drafting of the article. CG and MB contributed to the acquisition of data, analysis and interpretation of data, and to the drafting the article. RD contributed to the conception and design, acquisition of data and to the critical revision of the article. SB, RS and AV contributed to the acquisition of data and to the critical revision of the article. JB contributed to the conception and design, acquisition of data, analysis and interpretation of data, and to the drafting of the article. All authors read and approved the final article.
Funding Funding was obtained from the Dutch Kidney Foundation, Dutch Arthritis Association and NWO-AGIKO scholarship program.
Competing interests None.
Ethics approval Ethics approval was obtained from the ethics committees of all participating hospitals.
Provenance and peer review Not commissioned; externally peer reviewed.