Case report: A novel TET2 mutation in a patient with refractory cytopenia with multilineage dysplasia.

Myelodysplastic syndrome diagnosis of karyotypically normal patients may be elusive because it relies exclusively on morphological and clinical data. In routine practice, finding of an acquired mutation or a cytogenetic abnormality provides irrefutable evidence of the clonal nature of that disease. Recurrent deletions and somatic mutations in TET2, a gene involved in epigenetic regulation, have been reported in about 20% of adult patients with myelodysplastic syndrome. We report a novel g.95805C>T, nonsense TET2 mutation, leading to a premature stop codon (p.Gln913*), in an adult patient with refractory cytopenia with multilineage dysplasia.

Prophylactic donor lymphocyte infusions after moderately ablative chemotherapy and stem cell transplantation for hematological malignancies: high remission rate among poor prognosis patients at the expense of graft-versus-host disease.

We investigated the use of 'prophylactic' donor lymphocyte infusions (DLI) containing 1 x 107 CD3+ cells, given at 30, 60 and 90 days post-allogeneic blood and marrow transplantation (BMT), following conditioning with fludarabine 30 mg/m(2)/4 days and melphalan 70 mg/m(2)/2 days. GVHD prophylaxis consisted of cyclosporin A (CsA) 2 mg/kg daily with early tapering by day 60. Our goals were the rapid achievement of chimerism and disease control, providing an immunological platform for DLIs to treat refractory patients with hematological malignancies. Twelve heavily pre-treated patients with life expectancy less than 6 months were studied; none were in remission. Diagnoses were AML (n = 4), MDS (n = 1), ALL (n = 3), CML (n = 3) and multiple myeloma (n = 1). Response rate was 75%. Three patients are alive at a median of 450 days (range, 450-540). Two patients are in remission of CML in blast crisis and AML for more than 14 months. Median survival is 116 days (range, 25-648). Six patients received 12 DLIs; three patients developed acute GVHD after the first infusion and were excluded from further DLIs, but no GVHD occurred among patients receiving subsequent DLIs. One patient with CML in blast crisis went into CR after the first DLI. The overall incidence of acute GVHD was 70%. Primary causes of death were infections (n = 3), acute GVHD (n = 3), chronic GVHD (n = 1) and disease relapse (n = 2). We observed high response and chimerism rates at the expense of an excessive incidence of GVHD. DLI given at day +30 post BMT caused GVHD in 50% of the patients, and its role in this setting remains unclear.