MON-001 EFFICACY OF RITUXIMAB IN ADULT ONSET NEPHROTIC SYNDROME PATIENTS

Abstract

About 40% of idiopathic nephrotic syndrome (INS) show steroid dependence and 10 to 15% are steroid resistant. Therapeutic options for such patients remain limited. Rituximab is a murine- human chimeric anti CD20 monoclonal antibody used for depletion of B cells. Rituximab was first reported to have efficacy in childhood nephrotics. Ever since numerous reports and case series have suggested efficacy in steroid-dependent INS. Data from previous studies suggested that 2-4 doses of Rituximab is required for achieving remission. Prospective observational study. Patients between ages of 14 - 65 years. Biopsy proven Minimal change disease (MCD), Focal segmental glomerulosclerosis (FSGS) or Membranous nephropathy. (MGN) Patients with steroid dependent/Frequent Relapsing nephrotic syndrome(SDNS/FRNS). Patients with steroid resistant nephrotic syndrome. Patients with secondary Nephrotic Syndrome were excluded SIngle dose of Inj Rituximab was given (375 mg/m2 to a max of 500mg) and followed up for 6 months. Infusion related adverse reactions was noted Monitoring of CD19 levels was done on D2-5 and then monthly basis. Proteinuria was tested on a monthly basiis. Steroids were tapered in all patients after achieving remission. Other immunosuppression which was used in SRNS or SDNS as steroid sparing were stopped. Patients who developed relapses after receiving a dose of Rituximab: Dose and duration of prednisolone as in primary therapy of nephrotic syndrome was given.A repeat doses of rituximab was planned for unresponsive patients. The primary outcomes were changes in proteinuria and CD19 Levels following Rituximab. Secondary outcomes were study of any adverse reactions. 30 patients were included.22 were males and 8 were females. 24 patients were SDNS and 6 patients were SRNS. FSGS was the commonest histopathlogy (33%). The mean value at baseline proteinuria was 3494 mg/24 hrs (SD± 1738.84). All patients achieved remission after a single dose of Inj Rituximab, median time of complete remission was 30 days (P: 0.001). 1 patient had mild infusion related reaction which improved with slowing of infusion rate. Some minor infectious complications were observed. These included Tinea corporis in 1 patient in month 1, Pharyngitis in 1 patient in month 2 and month 3 each, while 1 patiient developed Rhinitis in month 3 and 2 patients in month 5. 1 patiient had an episode of watery diarrhea in month 4. CD19 levels were suppressed to <1% in all patients after a single dose. The levels of 12 patients recovered to > 1% after month 3 but 6 out of them remained in remission. 6 patients relapsed during the follow up period of 6 months. All of them were given a course of steroids (1 mg/kg). 4 of them were now steroid sensitive and achieved remission. 1 out of 2 remaining patients didnot consent for a repeat dose of Rituximab and was maintained on a lower dose of steroids to achieve remission, the other 1 patient received a repeat dose of Inj Rituximab following which achieved partial remission. Rituximab is effective in attaining a complete/partial remission in our study population.