Therapeutic implications of T-cell clonopathy of unknown significance in chronic immune thrombocytopenic purpura.

Immune thrombocytopenic purpura (ITP) is typically considered an autoimmune disorder related to the production of autoantibodies; however, recent evidence indicates that cell-mediated cytotoxicity may be important pathogenetically in some cases. We describe seven patients with chronic ITP and concurrent T-cell clonopathy of unknown significance (TCUS), who failed various treatment regimens for ITP, including steroids, gamma globulins, splenectomy and rituximab, but had anecdotal success with azathioprine. These observations support the notion that ITP has heterogeneous biologic mechanisms, and that patients with persistent chronic ITP should be evaluated for T-cell clonality and considered for treatment options that are directed against cytotoxic T-cells.