Introduction and Aims: Repeated renal flares is associated with unfavorable long-term renal outcomes in lupus nephritis (LN) patients. This study examined the risk factors for renal flares in the era of effective immunosuppressive treatments, and also the impact of mycophenolic acid maintenance on relapse.
Methods: All LN patients who were followed up in Queen Mary Hospital during the period of 1 January 1983 to 31 December 2013 were retrospectively reviewed. Episodes of renal flares were identified and the risk factors for these relapses were analyzed. The risk of flare was also examined according to the era before (1983-1997) and after (1998-2013) the availability of mycophenolic acid (MPA) treatment in our centre.
Results: A total of 346 episodes of renal relapses occurred in 184 patients (mean follow-up duration: 195.3±94.4 months). Multivariate analysis showed that age (OR 0.97; 95% CI 0.943-0.998; p=0.038), higher serum creatinine on presentation (OR 0.992; 95% CI 0.985-0.999; P=0.019), use of mycophenolic acid (MPA) as maintenance treatment (OR 0.322; 95% CI 0.0109-0.953; P=0.041) and achievement of complete remission after induction treatment (OR 0.394; 95% CI 0.175-0.886; P=0.024) conferred lower risk of renal flares. The choice of induction treatment, urine protein excretion and serological parameters on presentation showed no significant influence on subsequent flares (p all >0.05). Rates of renal flare were 0.044 and 0.024 relapse per patient-year before and after the availability of MPA (p<0.001). Better relapse free-survival was observed in patients who received corticosteroids and MPA maintenance when compared to patients on corticosteroids and azathioprine (AZA) (83% vs. 68%, 66% vs 43% at 5 and 10 years; P=0.048) (Figure 1). The relapse-free survival was also better in the era after MPA was available as compared to the era before MPA was available (80% vs 63% and 62% vs 37% at 5 and 10 years; p=0.009) (Figure 2).
Conclusions: The overall risk of relapse is low in the era of effective immunosuppressive therapies. The use of MPA maintenance is associated with lower long-term risk of relapse in LN as compared to AZA.
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