The etiology of ITP remains unknown but its pathogenesis consists of loss of tolerance to platelet antigens. There is a complex dysregulation of the immune system involving both the B cells and the T cells. Splenectomy is the standard second line option in steroid refractory chronic ITP patients. However, costs of surgery and reluctance for surgery in severely thrombocytopenic patients on part of surgeons are major obstacles in resource limited settings. Rituximab has been used in both the standard doses of 375 mg/m2 and low doses of 100 mg/m2 with similar results. We studied the utility of low dose Rituximab (@100 mg/m2 weekly × 4 doses) in resource limited settings. Overall response, complete response (CR) and partial response (PR) rates were 47.6% (10/21), 33.3% (7/21) and 14.3% (3/21) respectively. Median time to response in patients achieving CR was 75 days (range 45-185 days) while in patients achieving PR it was 105 days (range 45-165 days). However, there was no significant difference between males and females achieving CR or PR. We also observed that patients who had earlier responded to any form of treatment were more likely to respond to Rituximab treatment. The cumulative relapse free survival (RFS) at 13 months was 78%. By giving lower dose, six times less than conventional dosing dose, we have been able to demonstrate cost effectiveness in our study population. We were able to administer all the doses in day care without any major adverse events leading to further cost savings on in-patient care.
Keywords: Immune thrombocytopenic purpura; Low dose; Refractory; Rituximab.