Coexisting driver mutations in MPN: clinical and molecular characteristics of a series of 11 patients

OBJECTIVES

CML, PV, ET and PMF are so called classical MPN with distinct clinical phenotypes. The discovery of the BCR-ABL1 translocation and mutations in driver genes JAK2, MPL and CALR has provided novel insights in their pathogenesis. While these mutations are thought to be mutually exclusive, rare cases of MPN with coexisting driver mutations have been reported. However, little is known about the clinical, biological and molecular characteristics of these patients and the interaction of the neoplastic clones.

METHODS

We retrospectively studied 11 MPN patients with coexisting driver mutations (JAK2 V617F + BCR-ABL1: n = 8; CALR type 2 + BCR-ABL1: n = 1; JAK2 V617F + MPL W515: n = 1; JAK2 V617F + CALR type 1: n = 1). To assess possible associated molecular aberrations, we analysed DNA of six patients using NGS.

RESULTS

In four CML patients, decreasing BCR-ABL1 transcript levels with increasing JAK2 V617F allele burden under TKI were observed. This strongly suggests that the coexistence of driver mutations originates from two different clones growing independently. Additional somatic mutations were detected in 5 out of 6 (83%) patients affecting 4 different genes, confirming the heterogeneity of this study cohort. Suboptimal response to TKI was observed with a higher frequency (4/8 patients) than reported in conventional series of CML and the overall tolerance of treatment with hydroxyurea and/or imatinib in our series was poor.

CONCLUSION

Given the emergence of NGS in clinical practice, more similar cases will be identified in the coming years. The optimal treatment strategy for this rare group of patients is uncertain and toxicity of combination treatment may have to be considered.

Budd-Chiari syndrome: reassessment of a step-wise treatment strategy

BACKGROUND AND STUDY AIMS

The Budd-Chiari syndrome is a rare disorder characterized by hepatic venous outflow obstruction. A step-wise management was recently proposed. The aim of this study is to reassess our treatment approach and long-term outcome.

PATIENTS AND METHODS

The data of 37 Budd-Chiari patients, seen in our unit, were critically analyzed and compared with the ENVIE (European Network For Vascular Disorders of the Liver) data.

RESULTS

Most patients had multiple prothrombotic conditions (41%), of which an underlying myeloproliferative neoplasm was the most frequent (59%). The JAK2V617F mutation was associated with more complete occlusion of all hepatic veins (JAK2 mutation +: 70% vs JAK2 mutation -: 23% and a higher severity score. The step-wise treatment algorithm used in our unit, in function of the severity of the liver impairment and the number and the extension of hepatic veins occluded, resulted in the following treatments: only anticoagulation (n = 7.21%), recanalization procedure (n = 4.21%), portosystemic shunts (n = 9.26%) and liver transplantation (n = 14.44%). This resulted in a 10 year survival rate of 90%. Treatment of the underlying hemostatic disorder offered a low recurrence rate. None of the 21 patients with a myeloproliferative neoplasm died in relation to the hematologic disorder.

CONCLUSIONS

An individualized treatment regimen consisting of anticoagulation and interventional radiology and/or transplantation when necessary and strict follow-up of the underlying hematologic disorder, provided an excellent long-term survival, which confirm the data of the ENVIE study.

Myelofibrosis patients in Belgium: disease characteristics

OBJECTIVE

To date, only a small number of epidemiological studies on myelofibrosis have been performed. The current study aimed to characterize the myelofibrosis patient population in Belgium according to pre-defined disease parameters (diagnosis, risk categories, hemoglobin <10 g/dl, spleen size, constitutional symptoms, platelet count, myeloblast count), with a view to obtaining a deeper understanding of the proportion of patients that may benefit from the novel myelofibrosis therapeutic strategies.

METHODS

A survey was used to collect data on prevalence and disease parameters on all myelofibrosis patients seen at each of 18 participating hematologic centers in 2011. Aggregated data from all centers were used for analysis. Analyses were descriptive and quantitative.

RESULTS

A total of 250 patients with myelofibrosis were captured; of these, 136 (54%) were male and 153 (61%) were over 65 years old. One hundred sixty-five (66%) of myelofibrosis patients had primary myelofibrosis and 85 (34%) had secondary myelofibrosis. One hundred ninety-three myelofibrosis patients (77%) had a palpable spleen. About a third of patients (34%) suffered from constitutional symptoms. Two hundred twenty-two (89%) myelofibrosis patients had platelet count ≧50 000/μl and 201 (80%) had platelet count ≧100 000/μl. Of 250 patients, 85 (34%) had a myeloblast count ≧1%. Six (2%) patients had undergone a splenectomy. Thirteen (5·2%) patients had undergone radiotherapy for splenomegaly.

CONCLUSIONS

The results of this survey provide insight into the characteristics of the Belgian myelofibrosis population. They also suggest that a large proportion of these patients could stand to benefit from the therapies currently under development.

Treatment with lenalidomide (Revlimid®), cyclophosphamide (Endoxan®) and prednisone (REP) in relapsed/refractory multiple myeloma patients: results of a single centre retrospective study

Lenalidomide (Revlimid®) combined with intermittent dexamethasone (the RD regimen) is one of the current standards for treatment of patients with relapsed/refractory multiple myeloma (MM). However, since the disease in the majority of patients will become resistant to RD, or treatment with RD needs to be discontinued due to side effects, we evaluated the combination lenalidomide, low-dose oral cyclophosphamide, with prednisone (REP) in patients with relapsed/refractory MM previously exposed to RD. For this purpose, we performed a single centre retrospective study of the efficacy of REP in 19 patients with relapsed/refractory MM. Overall response rate (partial response or better) with REP was 68% compared with 83% with RD, but with a shorter time to response with the triplet REP. Time to progression after REP was 6 months. Overall the REP regimen was better tolerated compared to RD. We conclude that the REP regimen is an effective treatment regimen for patients with relapsed/refractory MM with good tolerance, warranting further exploration in prospective randomized trials.

A 75-year-old missionary with fever, splenomegaly and pancytopenia

We present a case of hyperreactive malarial splenomegaly, a disease which is exceptional in Caucasian people, but which is expected to become more important since the increasing number of travelling to tropical areas. It is the chronic stage of an abnormal long-term stimulation of the immune system secondary to plasmodial infection. Diagnostic criteria include long-term stay in an endemic zone, large splenomegaly and overproduction of both IgM and IgG antibodies. The disease can be treated by a short-term antimalarial therapy as long as the patient resides out of a malarial endemic country.

Thrombotic microangiopathy following intestinal transplantation: a single center experience

BACKGROUND

Transplant-related thrombotic microangiopathy (TMA) is a well-recognized complication of all types of transplantations. Despite its known relationship with immunosuppressive therapy, only a few cases have been reported following intestinal transplantation.

METHODS

We retrospectively reviewed the medical files of nine consecutive intestinal transplant patients between 2000 and 2008.

RESULTS

The diagnosis of TMA was established in 3 patients (33%). At diagnosis the immunosuppressive therapy consisted of tacrolimus (n = 3), combined with azathioprine (n = 1) or sirolimus (n = 2) and steroids (n = 2). The median time between transplantation and TMA was 104 days (range, 55-167 days). Levels of ADAMTS13, a von Willebrand protease, were within normal ranges in all 3 patients. Treatment consisted of stopping/tapering of tacrolimus, together with initiation of plasma therapy, leading to complete remission in all 3 patients. During further follow-up, all 3 patients showed severe graft rejection necessitating more profound immunosuppressive therapy, leading to graft loss in 1 patient and infection-related death in the 2 others. At a median follow-up of 52 months (range, 9-100 months) all remaining TMA-free patients (n = 6) were alive with functioning grafts under minimal immunosuppression.

CONCLUSION

Herein we have described 3 intestinal transplant patients who were diagnosed with transplantation-related TMA. Despite excellent disease control the final outcomes were dismal, which clearly contrasts with the outcome among TMA-free patients, who were all well with functioning grafts at last follow-up.

Role of CD4+ and CD8+ T cells in the rejection of heart or islet xenografts in recipients with xenotolerance in the innate immune compartment

To further study the interactions between innate and adaptive immunity in xenotransplantation, we explored the relative contribution of T-cell subsets in vascularized (heart) and cellular (islets) xenografts in a model with established xeno-non-reactivity of the innate system.

MATERIALS

Specific innate xenotolerance was induced in xenoheart (hamster) recipients (nude rats) by a tolerizing regimen (TR), consisting of donor antigen infusion, temporary natural killer (NK)-cell depletion and a 4-week administration of leflunomide. Hamster pancreatic islets were transplanted either 1 week after heart transplantation or alone and syngeneic T-cell adoptive transfer was performed 10 days later. Purified CD3(+), CD4(+), and CD8(+) T cells were given 2 weeks after withdrawal of all drugs. At the day of rejection, xenografts were removed for histology. Serum was taken and IgM and IgG xenoantibody titers were measured by flow cytometry.

RESULTS

Both heart and islet grafts were rejected after CD4(+) reconstitution. After CD8(+) T-cell adoptive transfer, cellular grafts were not rejected but vascularized grafts were rejected, although only after several months. Rejection in CD4(+) reconstituted nude rats was accompanied by the generation of predominantly IgG xenoantibodies.

CONCLUSION

CD4(+) T lymphocytes are able to rapidly initiate the rejection of islet xenografts in the presence of a xenotolerant innate immune system either by breaking the "innate tolerance" (e.g., by activating macrophages and NK-cells) or through a mechanism without any involvement of the innate tolerance (e.g., T-dependent IgG antibody production). In contrast, CD8(+) T cells provoke a late rejection of only xenoheart grafts.

Intergroup emotions: explaining offensive action tendencies in an intergroup context

Three studies tested the idea that when social identity is salient, group-based appraisals elicit specific emotions and action tendencies toward out-groups. Participants' group memberships were made salient and the collective support apparently enjoyed by the in-group was measured or manipulated. The authors then measured anger and fear (Studies 1 and 2) and anger and contempt (Study 3), as well as the desire to move against or away from the out-group. Intergroup anger was distinct from intergroup fear, and the inclination to act against the out-group was distinct from the tendency to move away from it. Participants who perceived the in-group as strong were more likely to experience anger toward the out-group and to desire to take action against it. The effects of perceived in-group strength on offensive action tendencies were mediated by anger.

Cloning and characterization of Leishmania donovani telomeres

We describe here the cloning and sequence characterization of the absolute termini of several telomeres from the human parasite Leishmania donovani using a vector-adapter protocol. The 3' protruding strand of L. donovani telomeres terminates with the sequence 5'-GGTTAGGGT-OH 3'. This single-stranded sequence is adjacent to tandemly repeated blocks of double-stranded sequence consisting of variable numbers of the hexameric repeat 5'-TAGGGT-3', variable numbers of an octameric repeat 5'-TGGTCATG-3', and a single 62-bp sequence, in that order. A number of additional, more chromosome-internal, nonrepeated sequences were found adjacent to the telomere sequences. Hybridization analyses indicated that some of these telomere adjacent sequences are found on all L. donovani chromosomes, some are more abundant on certain subsets of chromosomes, and some are unique to individual chromosomes.

[Secondary prevention of drug abuse: problems and examples]

Since 1992, the Federal Office of Public Health (FOPH) has been promoting an innovative approach of secondary drug use prevention. Our main purpose is to present this approach. For the FOPH, the objective of the measures in this field includes the development of concepts and means to detect, at an early stage, young people at risk, or whose drug consumption is recent or occasional, in order to help them. The basic principle of the strategy is to strengthen the protective role of the community network of the young people at risk. To illustrate this strategy, we briefly describe different projects supported by the FOPH; some of them are immediately launched on a national or regional scale, while others are innovative local or regional projects. Finally, we identify situations which are a priori more favourable to funding or support by the FOPH.