Impact of allogeneic hematopoietic cell transplant in patients with myeloid neoplasms carrying spliceosomal mutations.

Molecular predictors of outcome are increasingly important in determining optimal therapy for myeloid neoplasms. Mutations in the spliceosomal genes (U2AF1 and SRSF2) predict for poor outcomes in myelodysplastic syndromes (MDS) and related diseases. We investigated the effect of hematopoietic cell transplant (HCT) on the negative prognostic impact of U2AF1 and SRSF2 mutations. In total, 122 patients with MDS (30%), acute myeloid leukemia (51%), myeloproliferative neoplasms (MPN) (11%), and MDS/MPN (8%) receiving a HCT from 2003 to 2012 were evaluated for mutations in U2AF1 and SRSF2 by direct sequencing. Median time of follow up was 24 months (range 0.46-110). SRSF2 mutations were detected in 11 (10%) patients and U2AF1 in 3 (3%) patients. There were no significant differences in baseline characteristics between mutated and wild-type (WT) patients. Patients carrying SRSF2 and U2AF1 mutations had similar overall survival (P = 0.84), relapse mortality (P = 0.50), and non-relapse mortality (P = 0.72) compared to WT patients. However, taking into account disease status and cytogenetics in a subset of AML patients, SRSF2 and U2AF1 mutations were associated with worse survival (HR 3.71, P = 0.035).

Non-t(6;9) and Non-Inv(3) Balanced Chromosomal Rearrangements Are Associated With Poor Survival Outcomes in Myelodysplastic Syndromes.

BACKGROUND: Cytogenetics is an important predictor of survival in patients with myeloid malignancies including myelodysplastic syndromes (MDS). The roles of balanced chromosomal rearrangements (BCR) specifically balanced translocations and inversions in MDS are less established. We hypothesized that BCR are commonly found in MDS and might confer important prognostic and therapeutic effect. PATIENTS AND METHODS: Cytogenetic, hematologic, clinical, and survival data from a total of 302 MDS patients seen at the Cleveland Clinic between the years 2002 and 2011 were collected. Direct sequencing for genes relevant in MDS pathophysiology was performed on patients with BCR. Categorical data were analyzed using the χ2 test and survival outcomes were analyzed using the Kaplan-Meier method. RESULTS: Twenty-three patients (8%) carried non-t(6;9) and non-inv(3) BCR. These patients had short overall survival (OS) similar to patients with poor risk cytogenetics, defined according to the International Prognostic Scoring System, which was not altered by new single-nucleotide polymorphism arrays or acquired somatic uniparental disomy lesions. Among the detected somatic mutations, only patients harboring mutations in the RNA splicing gene serine/arginine-rich splicing factor 2 (SRSF2) conferred worse outcomes in this group of patients. Therapeutically, patients who received allogeneic hematopoietic cell transplantations had better OS compared with patients treated with pharmacologic therapies or best supportive care only. CONCLUSION: BCR are not common in MDS and are associated with poor survival, which might be influenced by the presence of SRSF2 mutation.

Splicing factor 3b subunit 1 (Sf3b1) haploinsufficient mice display features of low risk Myelodysplastic syndromes with ring sideroblasts.

BACKGROUND: The presence of somatic mutations in splicing factor 3b subunit 1 (SF3B1) in patients with Myelodysplastic syndromes with ring sideroblasts (MDS-RS) highlights the importance of the RNA-splicing machinery in MDS. We previously reported the presence of bone marrow (BM) RS in Sf3b1 heterozygous (Sf3b1 (+/-)) mice which are rarely found in mouse models of MDS. Sf3b1 (+/-) mice were originally engineered to study the interaction between polycomb genes and other proteins. METHODS: We used routine blood tests and histopathologic analysis of BM, spleen, and liver to evaluate the hematologic and morphologic characteristics of Sf3b1 (+/-) mice in the context of MDS by comparing the long term follow-up (15 months) of Sf3b1 (+/-) and Sf3b1 (+/+) mice. We then performed a comprehensive RNA-sequencing analysis to evaluate the transcriptome of BM cells from Sf3b1 (+/-) and Sf3b1 (+/+) mice. RESULTS: Sf3b1 (+/-) exhibited macrocytic anemia (MCV: 49.5 ± 1.6 vs 47.2 ± 1.4; Hgb: 5.5 ± 1.7 vs 7.2 ± 1.0) and thrombocytosis (PLTs: 911.4 ± 212.1 vs 878.4 ± 240.9) compared to Sf3b1 (+/+) mice. BM analysis showed dyserythropoiesis and occasional RS in Sf3b1 (+/-) mice. The splenic architecture showed increased megakaryocytes with hyperchromatic nuclei, and evidence of extramedullary hematopoiesis. RNA-sequencing showed higher expression of a gene set containing Jak2 in Sf3b1 (+/-) compared to Sf3b1 (+/+). CONCLUSIONS: Our study indicates that Sf3b1 (+/-) mice manifest features of low risk MDS-RS and may be relevant for preclinical therapeutic studies.

Familial systemic mastocytosis with germline KIT K509I mutation is sensitive to treatment with imatinib, dasatinib and PKC412.

Mastocytosis are myeloproliferative neoplasms commonly related to gain-of-function mutations involving the tyrosine kinase domain of KIT. We herein report a case of familial systemic mastocytosis with the rare KIT K509I germ line mutation affecting two family members: mother and daughter. In vitro treatment with imatinib, dasatinib and PKC412 reduced cell viability of primary mast cells harboring KIT K509I mutation. However, imatinib was more effective in inducing apoptosis of neoplastic mast cells. Both patients with familial systemic mastocytosis had remarkable hematological and skin improvement after three months of imatinib treatment, suggesting that it may be an effective front line therapy for patients harboring KIT K509I mutation.

Molecular genetics of myelofibrosis and its associated disease phenotypes.

In 2005, the discovery of Janus kinase 2 (JAK2) V617F mutation in approximately half of patients with myelofibrosis (MF) marked an important milestone in our understanding of the pathophysiology of MF. This has broadened our understanding of the disease pathogenesis and became the foundation for the development and subsequent clinical use of JAK inhibitors for MF. However, it is clear that other pathogenetic modifiers contribute to the disease diversity and phenotypic variability of MF. Novel genome scanning technologies were useful in the identification of recurrent molecular mutations in other genes including MPL, TET2, IDH1/2, DNMT3A, SH3B2 (LNK) and CBL in MF pointing out that other pathways might be important in addition to the JAK/STAT pathway. The biologic role and clinical implications of these molecular mutations in MF is currently under investigation. The main challenge is to understand the mechanisms whereby molecular mutations whether alone or in combination with other genetic and non-genetic events contribute to the pathogenesis of MF and eventually can explain the phenotypic variability among the MF patients. In the present review we will provide an overview of the molecular pathogenesis of MF describing past and recent discoveries in molecular markers and their possible relevance in disease phenotype.

Increased CDA expression/activity in males contributes to decreased cytidine analog half-life and likely contributes to worse outcomes with 5-azacytidine or decitabine therapy.

PURPOSE: The cytidine analogs 5-azacytidine and decitabine, used to treat myelodysplastic syndromes (MDS), produce a molecular epigenetic effect, depletion of DNA-methyltransferase 1 (DNMT1). This action is S-phase dependent. Hence, genetic factors that decrease the half-lives of these drugs could impact efficacy. Documentation of such impact, and elucidation of underlying mechanisms, could lead to improved clinical application. EXPERIMENTAL DESIGN: Cytidine deaminase (CDA) rapidly inactivates 5-azacytidine/decitabine. The effect of CDA SNP A79C and gender on CDA expression, enzyme activity, and drug pharmacokinetics/pharmacodynamics was examined in mice and humans, and the impact on overall survival (OS) was evaluated in 5-azacytidine/decitabine-treated patients with MDS (n = 90) and cytarabine-treated patients with acute myeloid leukemia (AML) (n = 76). RESULTS: By high-performance liquid chromatography (HPLC), plasma CDA activity was decreased as expected in individuals with the SNP A79C. Interestingly and significantly, there was an even larger decrease in females than in males. Explaining this decrease, liver CDA expression was significantly lower in female versus male mice. As expected, decitabine plasma levels, measured by mass spectrometry, were significantly higher in females. In mathematical modeling, the detrimental impact of shorter drug half-life (e.g., in males) was greater in low compared with high S-phase fraction disease (e.g., MDS vs. AML), because in high S-phase fraction disease, even a short exposure treats a major portion of cells. Accordingly, in multivariate analysis, OS was significantly worse in male versus female patients with MDS treated with 5-azacytidine/decitabine. CONCLUSIONS: Increased CDA expression/activity in males contributes to decreased cytidine analog half-life and likely contributes to worse outcomes with 5-azacytidine or decitabine therapy.

A case of mistaken identity: When lupus masquerades as primary myelofibrosis.

INTRODUCTION: Autoimmune myelofibrosis is an uncommon hematologic disease characterized by anemia, bone marrow myelofibrosis, and an autoimmune feature. Myelofibrosis is often associated with other conditions, including infections, nutritional/endocrine dysfunction, toxin/drug exposure, and connective tissue diseases, including scleroderma and systemic lupus erythematosus. Absence of clonal markers (JAK2) and heterogeneity of the symptoms often complicate the diagnosis. CASE PRESENTATION: Here, we present two cases of systemic lupus erythematosus-induced autoimmune myelofibrosis. The first case is of a 36-year-old African American female with diagnosis of systemic lupus erythematosus at the age of 12 years. The second patient is a 44-year-old African American male with family history of systemic lupus erythematosus who developed anemia and constitutional symptoms later on. Both patients showed hypercellularity and fibrotic changes of the bone marrow. Moreover, mutational analysis showed that both patients were wild type for JAK2 (V617F and exon 12) and MPL (exon 10). CONCLUSIONS: These two cases illustrate that anemic patients with fibrotic changes in the bone marrow without other clinicopathologic features associated with primary myelofibrosis in the presence of clinical manifestations and history of an autoimmune disease should suggest an autoimmune myelofibrosis. These cases demonstrate that a good clinical history combined with molecular technologies and pathomorphologic criteria are helpful in distinguishing between primary myelofibrosis and a nonclonal myelofibrosis from an associated condition.

Phase 2 study of the lenalidomide and azacitidine combination in patients with higher-risk myelodysplastic syndromes.

Lenalidomide and azacitidine each have activity in myelodysplastic syndromes (MDS) patients, where both microenvironment and cell-regulatory mechanisms contribute to disease pathogenesis. The objective of this multicenter, phase 2 expansion trial was to determine the efficacy and safety of combination therapy with azacitidine (75 mg/m(2)/d for 5 days) and lenalidomide (10 mg/d for 21 days; 28-day cycle) in patients with higher-risk MDS. Among 36 patients enrolled (18 phase 1, 18 phase 2), median age was 68 years (range, 47-78 years) and follow-up was 12 months (range, 3-55 years). IPSS categories included intermediate-1 (n = 5 patients with excess blasts), intermediate-2 (20), and high (11). Common grade 3/4 nonhematologic adverse events included febrile neutropenia (22% of patients), other infection (11%), pulmonary (11%), cardiac (11%), constitutional (11%), and dermatologic (11%). The overall response rate (per modified MDS International Working Group criteria) was 72%: 16 patients (44%) achieved a complete response (CR), and 10 (28%) had hematologic improvement. Median CR duration was 17+ months (range, 3-39+); median overall survival was 37+ months (range, 7-55+) for CR patients, and 13.6 months for the entire cohort (range, 3-55). TET2/DNMT3A/IDH1/2 mutational status was associated with response in a limited number of patients. The lenalidomide/azacitidine combination is well-tolerated and highly active in treating greater-risk MDS.

Immunomodulatory agents in myelofibrosis.

INTRODUCTION: The treatment options for patients with myelofibrosis (MF) remain limited. Anemia, thrombocytopenia, extramedullary hematopoiesis, constitutional symptoms, and disease progression are the primary causes of morbidity and mortality. Traditional non-transplant therapies remain non-curative. Moreover, in the JAK2 inhibitor era, no single pharmacologic agent has been shown to improve all MF-related clinical manifestations. Immunomodulatory agents (IMiDs), such as thalidomide and lenalidomide, have been useful in the treatment of some MF patients while newer IMiDs such as pomalidomide are showing promise in MF. AREAS COVERED: This review focuses on the biologic rationales of IMiDs and the clinical results supporting their use in MF. It includes data on the new IMiD, pomalidomide and also explores the possible utility of combining IMiDs with other agents. A PubMed search of articles related to IMiDs and myelofibrosis were conducted. Relevant studies and clinical studies with sample size of > 15 were included. EXPERT OPINION: In the JAK2 inhibitor era, IMiDs are alternative treatments in managing splenomegaly and constitutional symptoms. They remain useful in the treatment of cytopenias. Pomalidomide's good anemia response may lead to its inclusion as one of the frontline anemia therapies in MF. Molecular biomarkers may allow us to identify patients who will respond to IMiDs.

Short-term and long-term outcome of hemolytic uremic syndrome in Iranian children.

BACKGROUND: Hemolytic uremic syndrome (HUS) is the most common cause of acute renal failure during infancy. Many symptoms and clinical features have been proposed as prognostic factors for HUS in the short and long term, while the results of different studies have often been controversial. The aim of this study was to evaluate short-term and long-term outcomes of HUS in Iranian children. METHODS: Medical records of all 92 children suffering from HUS admitted to the pediatrics nephrology ward at Ali-Asghar Children Hospital in Tehran, Iran, from 1990 to 2004, were retrospectively reviewed. RESULTS: Out of 92 children, mortality was observed in 18 patients (19.6%) during the acute phase of the disease. Significant correlation between mortality and seizures, coma and hypertension in the acute phase was found (p<0.05). No association was observed between type of treatment and mortality (p>0.05). In the long-term, the presence of hypertension in the acute phase of the disease (p=0.023; relative risk [RR] = 3.89; 95% confidence interval [95% CI], 1.01-13.76), hypertension at discharge time (p<0.001; RR=10; 95% CI, 2.44-40.91) and need for dialysis (p=0.021; RR=1.38; 95% CI, 1.13-1.70) were shown to be significant risk factors for future hypertension in HUS patients. CONCLUSION: Central nervous system involvement is associated with mortality in the acute phase of HUS, whereas the severity of disease in the admission phase is related to occurrence of hypertension in future.

Prognosis of acute renal failure in children.

UNLABELLED: Acute renal failure (ARF) is the acute loss of renal function over a period of hours or days. Given the poor prognosis of ARF among children, there is some urgency to identifying more effective prognostic indicators for detecting disease onset. Such indicators would help provide the means of selecting patients who would benefit the most from early aggressive treatment. In this study we assessed the etiologic and prognostic indicators of ARF, including several risk factors such as sepsis, respiratory distress, age, among others, in 300 children who were admitted to the Ali Asghar Children's Hospital, Tehran, Iran, from 1990 to 2003. Statistical analysis was performed using multiple regression and chi-square methods, and a score to determine the prognosis of ARF in children was developed. RESULT: Based on the results of this study the three common causes of ARF are acute tubular necrosis (ATN, 38%), acute glumerulonephritis (24%) and hemolytic uremic syndrome (24.1%). The overall mortality rate among our patients was 24.7%, with the highest risk group being those patients suffering from ischemic ATN. In addition, the correlation (p<0.0005) between the etiology and mortality rate was particularly high in patients with ischemic ATN. Mortality was also high (68%) in children younger than 2 years. Multiple regression models revealed that among those factors that significantly differed between the survivors and nonsurvivors, only the necessity of dialysis (p<0.0005), the use of mechanical ventilation (p=0.05) and disseminated intravascular coagulation (p=0.038) can be regarded as independent determinants of ARF prognosis in children.