Primary immune thrombocytopenia (ITP) is an acquired immune-mediated disorder with absence of any underlying cause. Corticosteroids are the standard initial treatment. Splenectomy is the main second-line treatment. A trend to delay or avoid splenectomy has developed thanks to new agents like rituximab. Few studies have assessed the response rate to rituximab in chronic ITP. We performed the first meta-analysis of randomized clinical trials and observational studies on rituximab as an effective splenectomy-avoiding option in adult chronic ITP. Overall methods were adapted from published guidelines for meta-analysis (meta-analysis of observational studies in epidemiology and preferred reporting items for systematic reviews and meta-analyses). Two haematologist investigators carried out study selection and data extraction independently, recording overall response rate (ORR) and complete response (CR) as primary assessment criteria. Of 364 records were identified through electronic databases. Of 19 retrospective or prospective observational studies were retained after removing duplicate studies and full-text analyses. The ORR was 57% (95% confidence interval [CI]: 48-65), for 368 non-splenectomized patients after rituximab; CR was 41% (95% CI: 0·33-0·51) for 346 patients. Results were stable for ORR and CR in all sub-analyses. In univariate or multivariate mixed-effect meta-regression, age was the most relevant effect. According to our results, rituximab should be used in earlier in non-splenectomized patients.
© 2012 Blackwell Publishing Ltd.