We previously reported on the clinical use of cyclosporine (Neoral), alone or in combination with methotrexate (MTX), in the first 46 refractory rheumatoid arthritis (RA) patients treated at our centre between March 1996 and November 1997. Thirty of the 46 patients remained on cyclosporine at study completion (mean dose 2.98 mg/kg/day) with efficacy inferred by significant reductions in the prednisolone and MTX doses and creatinine maintained in an acceptable range. Early discontinuation was primarily related to non-serious side effects.
The 30 patients continuing cyclosporine were reviewed 12 months later in November 1998. Analysis included life-table techniques.
21 of the original 46 patients (46%) continued at a mean dose of 2.59 mg/kg/day after a mean of 23.4 months. Nine patients discontinued cyclosporine during this 12-month period: 3 due to inactive disease, 2 due to hypertension, 2 due to elevated creatinine, and 1 due to mononeuritis multiplex secondary to rheumatoid vasculitis, and 1 due to inefficacy. Patients continuing cyclosporine had a shorter disease duration (9.85 versus 15.5 years [P = 0.05]). The prednisolone dose decreased from a baseline value of 10.57 mg/day to 6.78 mg/day (P = 0.007) and the MTX dose from 15.6 mg/week to 13.1 mg/week (P = 0.02). The mean serum creatinine level increased from a baseline of 73.86 mumol/l to 85.8 mumol/l (16%). 21/30 patients on combination therapy with MTX showed no difference in discontinuation rates compared with those on cyclosporine alone. Life-table analysis showed a bimodal distribution with significantly increased cyclosporine discontinuation in the first 12 months (principally due to non-renal/hypertensive causes) versus the subsequent period.
This follow-up study indicates that the use of cyclosporine in refractory RA allows a reduction in the prednisolone and MTX doses. Utilization is longer in earlier disease and is unaffected by combination with MTX. Renal function is maintained within an acceptable range. The bimodal discontinuation curve reflects early patient/physician concern about minor side effects, while renal/hypertension changes resulted in later discontinuation.