Low- Versus High-dose Cyclophosphamide in Class III/IV Lupus Nephritis: A Retrospective Study from South Asia.
Introduction
The comparative efficacy of low-dose cyclophosphamide (LD-CYC) and high-dose cyclophosphamide (HD-CYC) for treatment of lupus in South Asians is not well established. We aimed to compare treatment outcomes in South Asian patients with class III and IV lupus nephritis treated with either regimen.


Method
This was a single-center, retrospective study conducted in Sri Lanka. Patients with biopsy-proven class III or IV lupus nephritis were recruited. The HD-CYC group was defined as having received ≥6 doses of 0.5-1 g/m2 cyclophosphamide (CYC) followed by quarterly doses. The LD-CYC group was defined as having received six doses of 500 mg CYC at two-weekly intervals. The primary outcome was treatment failure defined as persistent nephrotic range proteinuria or renal impairment at 6 months.


Results
Sixty-seven patients were recruited (HD-CYC 34, LD-CYC 33), all South Asian ethnicity. The HD-CYC group had received treatment between 2000 and 2013, and the LD-CYC group from 2013 onward. The HD-CYC and LD-CYC groups had 30/33 (90.9%) and 31/34 (91.2%) females, respectively. Nephrotic syndrome and nephrotic range proteinuria on presentation were seen in 22/33 (67%) and 20/32 (62%) in the HD-CYC and LD-CYC groups, respectively, and renal impairment was seen in 5/33 (15%) of the HD-CYC group and 7/32 (22%) of the LD-CYC group (P > 0.05). Treatment failure and complete or partial remission occurred in 7/34 (21%) and 28/34 (82%), respectively, of HD-CYC and 10/33 (30%) and 24/33 (73%), respectively, of LD-CYC (P > 0.05). Adverse events rates were similar.


Conclusion
This study suggests that LD-CYC and HD-CYC induction is comparable in South Asian patients with class III and IV lupus nephritis.