Novel germline JAK2R715T mutation causing PV-like erythrocytosis in 3 generations. Amelioration by Ropeg-Interferon.

Polycythemia vera (PV) is a clonal disorder arising from the acquired somatic mutations of the JAK2 gene, including JAK2V617F or several others in exon 12. A 38-year-old female had a stroke at age 32 and found to have elevated hemoglobin, normal leukocytes, normal platelets, and tested negative for JAK2V617F and exon 12 mutations. Next generation sequencing revealed a novel mutation: JAK2R715T in the pseudokinase domain (JH2) at 47.5%. Its presence in her nail DNA confirmed a germline origin. Her mother and her son similarly had erythrocytosis and a JAK2R715T mutation. Computer modeling indicated gain-of-function JAK2 activity. The propositus and her mother had polyclonal myelopoiesis, ruling out another somatic mutation-derived clonal hematopoiesis. Some erythroid progenitors of all three generations grew without erythropoietin, a hallmark of PV. The in vitro reporter assay confirmed increased activity of the JAK2R715T kinase. Similar to PV, the JAK2R715T native cells have increased STAT5 phosphorylation, augmented transcripts of prothrombotic and inflammatory genes, and decreased KLF2 transcripts. The propositus was not controlled by hydroxyurea, and JAK2 inhibitors were not tolerated; however, Ropeginterferon-alfa-2b (Ropeg-IFN-α) induced a remission. Ropeg-IFN-α treatment also reduced JAK2 activity in the propositus, her mother and JAK2V617F PV subjects. We report dominantly inherited erythrocytosis secondary to a novel germline JAK2R715T gain-of-function mutation with many but not all comparable molecular features to JAK2V617F PV. We also document a previously unreported inhibitory mechanism of JAK2 signaling by Ropeg-IFN-α.

Adjuvant Endocrine Therapy in Breast Cancer: A Novel e-Health Approach in Optimizing Treatment for Seniors (OPTIMUM): A Two-Group Controlled Comparison Pilot Study.

BACKGROUND: In women with hormone receptor positive breast cancer, adjuvant endocrine therapy (AET) is associated with a significant survival advantage. Nonadherence is a particular challenge in older women, even though they stand to benefit the most from AET. Therefore, a novel eHealth tool (OPTIMUM) that integrates real-time analysis of health administrative claims data was developed to provide point-of-care decision support for clinicians. OBJECTIVES: The objectives of the study are to determine the effectiveness of a patient-specific, real-time eHealth alert delivered at point-of-care in reducing rates of AET discontinuation and to understand patient-level factors related to AET discontinuation as well as to assess integration of eHealth alerts regarding deviations from best practices in administration of AET by cancer care teams. METHODS: A prospective, 2-group controlled comparison pilot study will be conducted at 2 urban, McGill University-affiliated hospitals, the Royal Victoria Hospital and St. Mary's Hospital. A minimum of 43 patients per study arm will be enrolled through site-level allocation. Follow-up is 1.5 years. Health care professionals at the intervention site will have access to the eHealth tool, which will report to them in real-time medical events with known associations to AET discontinuation, an AET adherence monitor, and a discontinuation alert. Cox proportional hazard ratios with 95% confidence intervals will estimate risks of AET discontinuation. Tests for significance will be 2-sided with a significance level of P<.05. RESULTS: This protocol has been approved and funded by the Canadian Institutes of Health Research. The study will evaluate site-level differences between AET discontinuation and AET adherence and assess care team actions at the intervention site. Participant enrollment into this project is expected to start September 2016 with primary data ready to present by June 2018. CONCLUSION: This study will offer an opportunity to verify the feasibility of integrating an eHealth tool that aims to improve the long-term management of breast cancer in a high-risk population by allowing more timely intervention to prevent or rapidly address AET discontinuation.

Laboratory Investigation of Myeloproliferative Neoplasms (MPNs): Recommendations of the Canadian Mpn Group.

OBJECTIVES: To standardize diagnostic investigations for myeloproliferative neoplasms (MPNs) to increase homogeneity in patient care and to streamline diagnostic approaches in the most efficient and cost-effective manner. METHODS: The development of Canadian expert consensus recommendations for the diagnosis of MPNs began with a review of the following: clinical evidence, daily practice, existing treatment guidelines, and availability of diagnostic tools. Each group member was assigned a specific topic, which they discussed with the entire group during several consensus meetings. RESULTS: This document provides the Canadian MPN group's recommendations, proposed diagnostic algorithms, and background evidence upon which decisions were made. CONCLUSIONS: Standardization of diagnostic investigations will increase homogeneity in patient care and provide a foundation for future clinical research in this rapidly evolving therapeutic area. Streamlining diagnostic approaches in the most efficient and cost-effective manner will also result in significant cost saving for the health care system.

Evolving Therapeutic Options for Polycythemia Vera: Perspectives of the Canadian Myeloproliferative Neoplasms Group.

Polycythemia vera (PV) is a clonal stem cell disorder characterized by erythrocytosis and associated with burdensome symptoms, reduced quality of life, risk of thrombohemorrhagic complications, and risk of transformation to myelofibrosis and acute myeloid leukemia. The discovery of the JAK2 V617 mutation marked a significant milestone in understanding the pathophysiology of the disease and subsequently the diagnostic and therapeutic approaches. The current diagnostic criteria for PV are based on hemoglobin level and presence of the JAK2 V617 mutation. The treatment is geared toward prevention of thrombotic events, normalization of blood counts, control of disease-related symptoms, and potential prolongation of survival. Cytoreductive therapy is indicated in patients at increased risk of thrombosis. Hydroxyurea (HU) remains the most commonly used first-line cytoreductive therapy and is superior to phlebotomy in reducing risk of arterial and venous thrombosis. Interferon (IFN) is used either at failure of HU or in selected patients as first-line therapy. The results of pegylated IFN in phase 2 studies appear encouraging, with molecular responses occurring in some patients. Ongoing phase 3 studies of HU versus pegylated IFN will define the optimal first-line cytoreductive therapy for PV. A recent phase 3 trial has shown the superiority of the JAK1/2 inhibitor ruxolitinib in comparison to best available treatment in HU-intolerant or -resistant patients. The therapeutic landscape of PV is likely to change in the near future. In this report, we assess the potential impact of the changing landscape of PV management on daily practice.

Use of complementary and alternative medicine by cancer patients at a Montreal hospital.

OBJECTIVES: To assess feasibility of methods for a future study of complementary and alternative medicine (CAM) use by cancer patients treated in conventional health care settings. METHODS: Patients aged 18 years and older, fluent in English or French, and diagnosed with cancer from St. Mary's Hospital Center, Montreal, Canada participated. Feasibility was measured by the rates of participation and CAM use in the past 1 and 12 months. Following the survey, one patient focus group was held to better understand cancer patient perspectives on discussions of CAM that occur or not with their family physicians. RESULTS: Of 103 patients approached, 100 (97.1%; 77% female, 87% white) participated. Overall, 86% and 91% of respondents used at least one CAM in the past 1 and 12 months, respectively. More patients with breast compared with colorectal and other cancers (90.2%, 86.2%, and 80%, respectively) used CAM in the previous year. In the past 1 and 12 months, natural health products were used by 70% and 80% of respondents, respectively; mind-body therapies by 61% and 64%, respectively, and CAM practitioners by 11% and 29%, respectively. More than 98% of patients used CAM to improve quality of life and 68% disclosed CAM use to their physicians. Four of 5 focus group participants used CAM. Patient-physician CAM discussions varied from receiving a CAM referral to complete dismissal of the topic. CONCLUSION: Recruitment methods were well accepted but a sampling strategy stratified by sex and ethnicity will ensure sufficient representation by males and non-whites. Whereas disclosure of natural health products use is occurring, informative CAM discussion is not.

Bone marrow mesenchymal stromal cells of patients with myeloproliferative disorders do not carry the JAK2-V617F mutation.

Myeloproliferative disorders (MPDs) are often associated with the presence of the JAK2-V617F mutation in hematopoietic cells. It is currently not known if this mutation is carried as well by bone marrow mesenchymal stromal cells (MSCs) in these patients. To test this hypothesis, we recruited seven patients with JAK2-V617F(+) MPD, isolated marrow MSCs and characterized their phenotype and mesenchymal differentiation capacity, and probed for JAK2-V617F genomic DNA mutation. We found that MSCs of most patients could be culture-expanded and had a phenotype and differentiation capacity similar to that of MSCs derived from normal subjects. Using real-time polymerase chain reaction and melting curve analysis with probes specific for the JAK2-V617F DNA mutation, we did not find the mutation in any of the MSC samples studied. These results demonstrate that, in the setting of MPD, MSC do not originate from the mutated hematopoietic progenitor clone.

Polycythemia vera is not initiated by JAK2V617F mutation.

OBJECTIVE: The somatic JAK2(V617F) mutation is seen in most polycythemia vera (PV) patients; however, it is not clear if JAK2(V617F) is the PV-initiating mutation. METHODS: In order to examine this issue, we developed a novel real-time quantitative allele-specific PCR, in which allelic discrimination is enhanced by the synergistic effect of a mismatch in the -1 position, and a locked nucleic acid (LNA) nucleoside at the -2 position. RESULTS: Determination of allelic frequencies was reproducible (SD = 1.5%) and sensitive--0.1% mutant allele detected in 40 ng of DNA. The JAK2(V617F) frequency in clonal granulocytes from 3 PV females was less than 50% (27.5 +/- 11) and in 7 females greater than 50% (75 +/- 10.5). We also found that wild-type JAK2 BFU-E colonies from PV patients can grow without erythropoietin. The identification of the primary genetic lesion resulting in PV is essential for the development of novel therapeutic strategies. CONCLUSION: Our studies correlating the frequency of JAK2(V617F) mutant allele and clonality, as well as the presence of homozygous wild-type JAK2 erythropoietin-independent erythroid colonies, provide compelling evidence that the JAK2(V617F) is not the PV-initiating mutation. This supports a model wherein the JAK2(V617F) mutation arises as a secondary genetic event. Furthermore, our results indicate that an undefined molecular lesion, preceding JAK2(V617F), is responsible for clonal hematopoiesis in PV. We conclude that development of therapeutic strategies that target the JAK2(V617F) clonal cells may not be sufficient for eradication of PV.

Mutations of von Hippel-Lindau tumor-suppressor gene and congenital polycythemia.

The von Hippel-Lindau (pVHL) protein plays an important role in hypoxia sensing. It binds to the hydroxylated hypoxia-inducible factor 1 alpha (HIF-1 alpha) and serves as a recognition component of an E3-ubiquitin ligase complex. In hypoxia or secondary to a mutated VHL gene, the nondegraded HIF-1 alpha forms a heterodimer with HIF-beta and leads to increased transcription of hypoxia-inducible genes, including erythropoietin (EPO). The autosomal dominant cancer-predisposition von Hippel-Lindau (VHL) syndrome is due to inheritance of a single mutated allele of VHL. In contrast, we recently showed that homozygous germline 598C-->T VHL mutation leads to Chuvash polycythemia (CP). We subsequently found VHL mutations in three unrelated individuals unaffected with CP, one of whom was compound heterozygous for the 598C-->T mutation and another VHL mutation. We now report seven additional polycythemic patients with VHL mutations in both alleles. Two Danish siblings and another American boy were homozygous for the VHL 598C-->T mutation. Three unrelated white Americans were compound heterozygotes for 598C-->T and another VHL mutation, 562C-->G in two and 574C-->T in the third. Additionally, a Croatian boy was homozygous for a 571C-->G VHL mutation, the first example of homozygous VHL germline mutation causing polycythemia, other than the VHL 598C-->T mutation. We have not observed VHL syndrome-associated tumors in polycythemic subjects or their heterozygous relatives; however, this will need to be evaluated by longitudinal studies. Over all, we found that up to half of the consecutive patients with apparent congenital polycythemia and increased serum Epo we have examined have mutations of both VHL alleles. Those findings, along with reports of CP, underscore that VHL mutations are the most frequent cause of congenital polycythemia and define a new class of polycythemic disorder, polycythemias due to augmented hypoxia sensing.

Discrimination of polycythemias and thrombocytoses by novel, simple, accurate clonality assays and comparison with PRV-1 expression and BFU-E response to erythropoietin.

Essential thrombocythemia (ET) and polycythemia vera (PV) are clonal myeloproliferative disorders that are often difficult to distinguish from other causes of elevated blood cell counts. Assays that could reliably detect clonal hematopoiesis would therefore be extremely valuable for diagnosis. We previously reported 3 X-chromosome transcription-based clonality assays (TCAs) involving the G6PD, IDS, and MPP1 genes, which together were informative in about 65% of female subjects. To increase our ability to detect clonality, we developed simple TCA for detecting the transcripts of 2 additional X-chromosome genes: Bruton tyrosine kinase (BTK) and 4-and-a-half LIM domain 1 (FHL1). The combination of TCA established the presence or absence of clonal hematopoiesis in about 90% of female subjects. We show that both genes are subject to X-chromosome inactivation and are polymorphic in all major US ethnic groups. The 5 TCAs were used to examine clonality in 46 female patients along with assays for erythropoietin-independent erythroid colonies (EECs) and granulocyte PRV-1 mRNA levels to discriminate polycythemias and thrombocytoses. Of these, all 19 patients with familial polycythemia or thrombocytosis had polyclonal hematopoiesis, whereas 22 of 26 patients with clinical evidence of myeloproliferative disorder and 1 patient with clinically obscure polycythemia were clonal. Interestingly, interferon alpha therapy in 2 patients with PV was associated with reversion of clonal to polyclonal hematopoiesis. EECs were observed in 14 of 14 patients with PV and 4 of 12 with ET, and increased granulocyte PRV-1 mRNA levels were found in 9 of 13 patients with PV and 2 of 12 with ET. Thus, these novel clonality assays are useful in the diagnosis and follow-up of polycythemic conditions and disorders with increased platelet levels.