Identification of gene expression-based prognostic markers in the hematopoietic stem cells of patients with myelodysplastic syndromes.

PURPOSE: The diagnosis of patients with myelodysplastic syndromes (MDS) is largely dependent on morphologic examination of bone marrow aspirates. Several criteria that form the basis of the classifications and scoring systems most commonly used in clinical practice are affected by operator-dependent variation. To identify standardized molecular markers that would allow prediction of prognosis, we have used gene expression profiling (GEP) data on CD34+ cells from patients with MDS to determine the relationship between gene expression levels and prognosis. PATIENTS AND METHODS: GEP data on CD34+ cells from 125 patients with MDS with a minimum 12-month follow-up since date of bone marrow sample collection were included in this study. Supervised principal components and lasso penalized Cox proportional hazards regression (Coxnet) were used for the analysis. RESULTS: We identified several genes, the expression of which was significantly associated with survival of patients with MDS, including LEF1, CDH1, WT1, and MN1. The Coxnet predictor, based on expression data on 20 genes, outperformed other predictors, including one that additionally used clinical information. Our Coxnet gene signature based on CD34+ cells significantly identified a separation of patients with good or bad prognosis in an independent GEP data set based on unsorted bone marrow mononuclear cells, demonstrating that our signature is robust and may be applicable to bone marrow cells without the need to isolate CD34+ cells. CONCLUSION: We present a new, valuable GEP-based signature for assessing prognosis in MDS. GEP-based signatures correlating with clinical outcome may significantly contribute to a refined risk classification of MDS.

Mutation patterns of 16 genes in primary and secondary acute myeloid leukemia (AML) with normal cytogenetics.

Acute myeloid leukemia patients with normal cytogenetics (CN-AML) account for almost half of AML cases. We aimed to study the frequency and relationship of a wide range of genes previously reported as mutated in AML (ASXL1, NPM1, FLT3, TET2, IDH1/2, RUNX1, DNMT3A, NRAS, JAK2, WT1, CBL, SF3B1, TP53, KRAS and MPL) in a series of 84 CN-AML cases. The most frequently mutated genes in primary cases were NPM1 (60.8%) and FLT3 (50.0%), and in secondary cases ASXL1 (48.5%) and TET2 (30.3%). We showed that 85% of CN-AML patients have mutations in at least one of ASXL1, NPM1, FLT3, TET2, IDH1/2 and/or RUNX1. Serial samples from 19 MDS/CMML cases that progressed to AML were analyzed for ASXL1/TET2/IDH1/2 mutations; seventeen cases presented mutations of at least one of these genes. However, there was no consistent pattern in mutation acquisition during disease progression. This report concerns the analysis of the largest number of gene mutations in CN-AML studied to date, and provides insight into the mutational profile of CN-AML.

Immune thrombocytopaenia in adults: a single-centre retrospective review of patients presenting over 7 years.

AIM: To compare the investigation and management of adult immune thrombocytopaenia in our institution with international guidelines. METHOD: Adults presenting with immune thrombocytopaenia over a 7-year period were identified from a database. Written and electronic case records were reviewed. Patient demographics, results of investigations and management were recorded and compared with international guidelines. RESULTS: ITP was mild or asymptomatic in 57 of 67 patients (85%). Bone marrow aspiration was performed in 45 patients including 23 of 45 patients under 60 yrs. 15 patients (22%) were tested for HIV at presentation. 28 patients (42%) were inpatients including 18 patients who were asymptomatic or mildly symptomatic. 53 patients (79%) received first-line treatment with oral prednisone including 6 who were asymptomatic with platelets >30x10(9)/L. Splenectomy was performed in 17 patients at a median 7 months after diagnosis. CONCLUSION: Guidelines were followed in most cases although bone marrow aspirates were often performed unnecessarily in young patients. HIV testing was infrequently requested and should be considered in all new patients presenting with ITP. Asymptomatic patients have a low risk of serious or life-threatening bleeding and do not require admission to hospital. Most patients will eventually achieve a platelet count >30x10(9)/L off treatment.

Successful treatment of transplant-associated microangiopathy with rituximab.

The microangiopathic anaemia with thrombocytopenia--which can occur after haematopoietic stem cell transplant--resembles thrombotic thrombocytopenic purpura but has different pathophysiology and does not respond to plasma exchange. We describe a patient with severe manifestations of this disorder who recovered promptly following treatment with rituximab, an anti-CD20 antibody.