PB0689 - Long-term outcome of refractory immune thrombocytopenia after splenectomy

Background: Refractory immune thrombocytopenia (ITP) is defined as severe thrombocytopenia that is not responsive or relapse after splenectomy. Clinical data of refractory ITP had been scarce.

Aims: We aimed to understand the natural history and clinical landscape of refractory ITP, especially the long-term outcome and treatment response to steroids, immunosuppressants and TPO-RAs.

Methods: We retrospective collected patients who underwent splenectomy between 2000 and 2016 Chang Gung Memorial Hospital at Linkou. The diagnosis was reviewed and patients with ITP were included for analysis.

Results: Forty-one patients (6 male) with refractory ITP were identified. The median age was 41. Twenty-four patients had no response to splenectomy (i.e. primary refractory ITP) whereas 17 had relapse following splenectomy. After splenectomy failure, steroids alone were given to 16, steroids and azathioprine to 12, steroids and danazol to 2, azathioprine alone to 2, eltrombopag and rituximab to 1 patient each. Three patients had spontaneous complete remission (CR) without treatment. Among 37 evaluable patients, 22 had complete, 9 had partial and 6 had no response. Response rate was 78.3% for primary refractory disease and 92.9% for relapsed disease (odd ratio 0.28, P=0.376). CR rate was 43.5% for primary refractory disease and 85.7% for relapsed disease (odd ratio 0.13, P=0.016). Median time to response was 52.0 days for primary refractory disease and 31.5 days for relapsed disease (P=0.536). Eleven patients received eltrombopag treatment in subsequent treatment. Most had responses but not all responses were durable. Marked platelet count fluctuation is common but eltrombopag was continued in most patients.

Conclusion(s): Refractory ITP has a relatively favorable outcome. Most patients received steroid-based treatment with a response rate of 84% and CR rate 59%. Primary refractory ITP patients have apparently lower response and significantly lower CR rates. After failure of steroids and immunosuppressants, eltrombopag is a good treatment choice for refractory ITP.