High pretreatment peripheral blood T-cell receptor clonality as a predictor of prolonged response in immune thrombocytopenia.

Left panel: Scheme of the XPAG-immune thrombocytopenia trial. The dexamethasone (DEX) arm consisted of DEX 40 mg/day for days 1-4 for one to three cycles every 28 days to a maximum of 12 weeks, cycles 2 + 3 were optional. Patients randomised to eltrombopag (ETB) + DEX received eltrombopag in combination with a short course of high-dose DEX beginning on day 1 (40 mg/day during days 1-4). The starting dose of ETB was 50 mg/day for 2 weeks; thereafter, the ETB dose was increased by 25 mg for all patients who did not achieve the target platelet count of ≥50 × 109/L. The ETB tapering was performed by decreasing the dose by 25 mg every 2 weeks to a minimum dose of 25 mg every other day for all patients. Right upper panel: Clinical outcomes in patients treated with first-line ETB + DEX. Patients displayed a qualitatively longer response duration and qualitatively reduced usage of rescue medication. Right lower panel: The immunological T-cell response was different in treatment responders and non-responders. Patients with sustained response (responders) displayed a high T-cell clonality at baseline. Clones are depicted as bubbles (right side).