Somatic CALR mutations in myeloproliferative neoplasms with nonmutated JAK2.

BACKGROUND: Somatic mutations in the Janus kinase 2 gene (JAK2) occur in many myeloproliferative neoplasms, but the molecular pathogenesis of myeloproliferative neoplasms with nonmutated JAK2 is obscure, and the diagnosis of these neoplasms remains a challenge. METHODS: We performed exome sequencing of samples obtained from 151 patients with myeloproliferative neoplasms. The mutation status of the gene encoding calreticulin (CALR) was assessed in an additional 1345 hematologic cancers, 1517 other cancers, and 550 controls. We established phylogenetic trees using hematopoietic colonies. We assessed calreticulin subcellular localization using immunofluorescence and flow cytometry. RESULTS: Exome sequencing identified 1498 mutations in 151 patients, with medians of 6.5, 6.5, and 13.0 mutations per patient in samples of polycythemia vera, essential thrombocythemia, and myelofibrosis, respectively. Somatic CALR mutations were found in 70 to 84% of samples of myeloproliferative neoplasms with nonmutated JAK2, in 8% of myelodysplasia samples, in occasional samples of other myeloid cancers, and in none of the other cancers. A total of 148 CALR mutations were identified with 19 distinct variants. Mutations were located in exon 9 and generated a +1 base-pair frameshift, which would result in a mutant protein with a novel C-terminal. Mutant calreticulin was observed in the endoplasmic reticulum without increased cell-surface or Golgi accumulation. Patients with myeloproliferative neoplasms carrying CALR mutations presented with higher platelet counts and lower hemoglobin levels than patients with mutated JAK2. Mutation of CALR was detected in hematopoietic stem and progenitor cells. Clonal analyses showed CALR mutations in the earliest phylogenetic node, a finding consistent with its role as an initiating mutation in some patients. CONCLUSIONS: Somatic mutations in the endoplasmic reticulum chaperone CALR were found in a majority of patients with myeloproliferative neoplasms with nonmutated JAK2. (Funded by the Kay Kendall Leukaemia Fund and others.).

Somatic SF3B1 mutation in myelodysplasia with ring sideroblasts.

BACKGROUND: Myelodysplastic syndromes are a diverse and common group of chronic hematologic cancers. The identification of new genetic lesions could facilitate new diagnostic and therapeutic strategies. METHODS: We used massively parallel sequencing technology to identify somatically acquired point mutations across all protein-coding exons in the genome in 9 patients with low-grade myelodysplasia. Targeted resequencing of the gene encoding RNA splicing factor 3B, subunit 1 (SF3B1), was also performed in a cohort of 2087 patients with myeloid or other cancers. RESULTS: We identified 64 point mutations in the 9 patients. Recurrent somatically acquired mutations were identified in SF3B1. Follow-up revealed SF3B1 mutations in 72 of 354 patients (20%) with myelodysplastic syndromes, with particularly high frequency among patients whose disease was characterized by ring sideroblasts (53 of 82 [65%]). The gene was also mutated in 1 to 5% of patients with a variety of other tumor types. The observed mutations were less deleterious than was expected on the basis of chance, suggesting that the mutated protein retains structural integrity with altered function. SF3B1 mutations were associated with down-regulation of key gene networks, including core mitochondrial pathways. Clinically, patients with SF3B1 mutations had fewer cytopenias and longer event-free survival than patients without SF3B1 mutations. CONCLUSIONS: Mutations in SF3B1 implicate abnormalities of messenger RNA splicing in the pathogenesis of myelodysplastic syndromes. (Funded by the Wellcome Trust and others.).

p53 and cell cycle independent dysregulation of autophagy in chronic lymphocytic leukaemia.

BACKGROUND: Activation of wild-type p53 with the small molecule sirtuin inhibitor Tenovin-6 (Tnv-6) induces p53-dependent apoptosis in many malignant cells. In contrast, Tnv-6 reduces chronic lymphocytic leukaemia (CLL) cell viability with dysregulation of autophagy, without increasing p53-pathway activity. METHODS: Here, we have investigated whether a quiescent phenotype (unique to CLL) determines the Tnv-6 response, by comparing the effects of Tnv-6 on activated and proliferating CLL. We further studied if these responses are p53-dependent. RESULTS: Unlike quiescent cells, cell death in activated cultures treated with Tnv-6 was consistently associated with p53 upregulation. However, p53 acetylation remained unchanged, without caspase-3 cleavage or apoptosis on electron microscopy. Instead, cellular ultrastructure and protein profiles indicated autophagy inhibition, with reduced ubiquitin-proteasome activity. In specimens with mutant TP53 cultured with Tnv-6, changes in the autophagy-associated protein LC3 occurred independently of p53. Cells treated with Tnv-6 analogues lacking sirtuin inhibitory activity had attenuated LC3 lipidation compared with Tnv-6 (P0.01), suggesting that autophagy dysregulation occurs predominantly through an effect on sirtuins. CONCLUSION: These cell cycle and p53-independent anti-leukaemic mechanisms potentially offer novel therapeutic approaches to target leukaemia-sustaining cells in CLL, including in disease with p53-pathway dysfunction. Whether targets in addition to sirtuins contribute to autophagy dysregulation by Tnv-6, requires further investigation.

The blind men and the AML elephant: can we feel the progress?

The pharmacological therapy of non-promyelocytic acute myeloid leukemia (AML) has remained unchanged for over 40 years with an anthracycline-cytarabine combination forming the backbone of induction treatments. Nevertheless, the survival of younger patients has increased due to improved management of the toxicity of therapies including stem cell transplantation. Older patients and those with infirmity that precludes treatment-intensification have, however, not benefited from improvements in supportive care and continue to experience poor outcomes. An increased understanding of the genomic heterogeneity of AML raises the possibility of treatment-stratification to improve prognosis. Thus, efforts to identify agents with non-conventional anti-leukemic effects have paralleled those aiming to optimize leukemia cell-kill with conventional chemotherapy, resulting in a number of randomized controlled trials (RCT). In the last 18 months, RCTs investigating the effects of vosaroxin, azacitidine and gemtuzumab ozogamycin and daunorubicin dose have been reported with some studies indicating a statistically significant survival benefit with the investigational agent compared with standard therapy and potentially, a new era in AML therapeutics. Given the increasing costs of cancer care, a review of these studies, with particular attention to the magnitude of clinical benefit with the newer agents would be useful, especially for physicians treating patients in single-payer health systems.

Ester Prodrugs of Ketoprofen: Synthesis, Hydrolysis Kinetics and Pharmacological Evaluation.

The ester prodrugs of ketoprofen with various naturally available antioxidants; menthol, thymol, eugenol, guiacol, vanillin and sesamol have been synthesized by the dicyclohexyl carbodiimide (DCC) coupling method, purified and characterized by spectral data. Further, their, partition coefficients have been determined as well as, hydrolytic studies performed. The synthesized compounds are more lipophilic compared to the parent moieties and are stable in acidic environment, which is a prerequisite for their oral absorption. Under gastric as well as intestinal pH conditions these prodrugs showed variable susceptibility towards hydrolysis. The title compounds when evaluated for anti-inflammatory, analgesic activities and ulcerogenicity, showed improvement over the parent drug.

Rituximab is effective in the management of refractory autoimmune cytopenias occurring after allogeneic stem cell transplantation.

Autoimmune haemolytic anaemia (AIHA), immune thrombocytopenia (ITP) and autoimmune neutropenia (AIN) are well-recognised complications of allogeneic stem cell transplantation (SCT), but have previously only been reported in the context of myeloablative conditioning regimens. Management of AIHA, ITP or AIN occurring after allogeneic SCT is unsatisfactory since they frequently prove refractory to conventional therapies including splenectomy. As a consequence, autoimmune cytopenias occurring after allogeneic SCT are associated with substantial morbidity and mortality. We report four patients who developed AIHA or ITP after allogeneic transplantation -- three of which occurred after a reduced-intensity conditioning (RIC) regimen. All patients demonstrated a complete response to Rituximab, having failed to respond to conventional treatment including high-dose prednisolone and intravenous immunoglobulin (IVIg). We conclude that Rituximab can be a valuable agent in the management of autoimmune cytopenias occurring after allogeneic SCT and that autoimmune cytopenias may be a hitherto unrecognised complication of RIC regimens.

Functional disturbance of marrow stromal microenvironment in the myelodysplastic syndromes.

The potential contribution of abnormal marrow stromal function to ineffective haemopoiesis in the myelodysplastic syndromes is unclear. We have compared the ability of stromal layers from normal (n = 7) and myelodysplastic (n = 9) marrow to alter proliferation and survival of the granulocyte-macrophage colony-stimulating factor/interleukin-3-dependent cell line F-36P. Co-cultures for 72 h in the absence of exogenous cytokines were either in direct contact with stroma or separated by transwell inserts. On normal stromal layers, the ratio of adherent F-36P cells relative to stromal cells increased from a mean of 0.2 +/- 0.01 (s.d.) at 4 h of co-culture to 0.34 +/- 0.08 after 72 h (n = 7). Corresponding values on myelodysplastic stroma (0.2 +/- 0.02 at 4 h and 0.35 +/- 0.05 at 72 h; n = 9) indicated that the ability of myelodysplastic stromal layers to regulate short-term proliferation of F-36P cells may be similar to normal. Apoptosis of F-36P cells was quantified after co-culture with normal or myelodysplastic stroma: results from myelodysplastic co-cultures were standardized as a fraction of values from co-cultures with paired normal stroma (apoptotic ratio). Augmented apoptosis of F-36P cells was detected in 8/9 co-cultures with myelodysplastic stroma (mean = 15.7 +/- 9.7%, n = 9), compared with corresponding normal stroma (mean = 12.4 +/- 4.6%, n = 7, P < 0.05) with a mean apoptotic ratio of 1.4 +/- 0.5 (P < 0.05). There was no correlation between stroma-related apoptosis and FAB type, tumour necrosis factor-alpha concentrations in the culture supernatant or numbers of stromal macrophages, and no evidence of involvement of the Fas pathway. Increased apoptosis was detected in cells grown in transwell inserts over stroma (23.8 +/- 3%, n = 5) compared to adherent cells in cultures with normal stromal layers, but this survival difference was not observed in co-cultures with myelodysplastic stroma. These results suggest that abnormal stromal function in patients with myelodysplastic syndromes may contribute to increased apoptosis of haemopoietic cells within the marrow microenvironment. The effect appears to be dependent on close cellular contact, rather than the release of soluble factors, but the exact mechanism remains unclear.

Validation of WHO classification-based Prognostic Scoring System (WPSS) for myelodysplastic syndromes and comparison with the revised International Prognostic Scoring System (IPSS-R). A study of the International Working Group for Prognosis in Myelodysplasia (IWG-PM).

A risk-adapted treatment strategy is mandatory for myelodysplastic syndromes (MDS). We refined the World Health Organization (WHO)-classification-based Prognostic Scoring System (WPSS) by determining the impact of the newer clinical and cytogenetic features, and we compared its prognostic power to that of the revised International Prognostic Scoring System (IPSS-R). A population of 5326 untreated MDS was considered. We analyzed single WPSS parameters and confirmed that the WHO classification and severe anemia provide important prognostic information in MDS. A strong correlation was found between the WPSS including the new cytogenetic risk stratification and WPSS adopting original criteria. We then compared WPSS with the IPSS-R prognostic system. A highly significant correlation was found between the WPSS and IPSS-R risk classifications. Discrepancies did occur among lower-risk patients in whom the number of dysplastic hematopoietic lineages as assessed by morphology did not reflect the severity of peripheral blood cytopenias and/or increased marrow blast count. Moreover, severe anemia has higher prognostic weight in the WPSS versus IPSS-R model. Overall, both systems well represent the prognostic risk of MDS patients defined by WHO morphologic criteria. This study provides relevant in formation for the implementation of risk-adapted strategies in MDS.

Resolution of sarcoidosis after allogeneic bone marrow transplantation with donor lymphocyte infusions.

Abnormalities of immune surveillance may contribute to the development of myeloid malignancy as well as immune-mediated diseases. In leukaemia, allogeneic haemopoietic stem cell transplantation (alloHSCT) has been used to induce disease remission, in part by restoring mechanisms of immune regulation. Although, by the same principle, allogeneic stem cell transplantation is an attractive option for the treatment of immunological disorders, it is unclear whether remission after transplantation is due to pre-transplant conditioning, or modulation of auto-reactive lymphocytes by cells in the allograft. We report the case of a patient with chronic myeloid leukaemia (CML) who received an allogeneic bone marrow transplant (alloBMT) from his brother. He subsequently suffered a cytogenetic and molecular relapse of CML. At the same time, sarcoidosis involving the marrow was diagnosed. He was treated with donor lymphocyte infusions (DLI) and attained remission from CML; in addition, no giant cell granulomas were detected in the marrow, indicating resolution of sarcoidosis. This case illustrates the need for further studies on the role of T cell-based therapies in the management of immune-mediated disorders.

Varicella zoster meningoencephalitis following treatment for dermatomal zoster in an alloBMT patient.

Herpes zoster infections are frequently observed after allogeneic bone marrow transplantation (alloBMT). In the majority of cases, the infection is restricted to specific dermatomes and responds to oral acyclovir, without visceral dissemination. We report the case of a 40-year-old male who developed dermatomal herpetic infection 8 months post alloBMT. The herpetic rash responded well to treatment with high-dose oral acyclovir. However, within a week of cessation of therapy, the patient re-presented with dermatomal zoster and meningoencephalitis. Although the cutaneous lesions resolved with intravenous acyclovir, clinical features of meningoencephalitis persisted, along with evidence of varicella zoster virus (VZV) DNA in cerebrospinal fluid (CSF). A satisfactory response to treatment was observed only after the addition of intravenous foscarnet to acyclovir. Based on our experience with this patient, we suggest that in a subset of alloBMT recipients, late dermatomal herpes zoster infections may respond only partially to treatment with standard oral acyclovir. The use of oral acyclovir preparations with higher bioavailability (valacyclovir) or intravenous acyclovir early on may prevent the considerable morbidity associated with disseminated zoster infection. Bone Marrow Transplantation (2000) 26, 795-796.

Recurrent penicillin-resistant pneumococcal sepsis after matched unrelated donor (MUD) transplantation for refractory T cell lymphoma.

Patients who undergo splenectomy and recipients of allogeneic marrow (alloBMT) or peripheral stem cell transplantation are at increased risk of overwhelming infection from encapsulated organisms such as Streptococcus pneumoniae, Haemophilus influenzae and Neisseria meningitidis. As prophylaxis against these pathogens splenectomised patients are immunised and may also receive antibiotics for life. We report relapsing overwhelming sepsis caused by penicillin-resistant pneumococcus in a patient who was immunised and received prophylactic phenoxymethylpenicillin for 8 months following splenectomy and matched unrelated donor (MUD) marrow transplantation for refractory T cell lymphoma. No obvious focus of sepsis was found during any of the three episodes and S. pneumoniae serogroup 6, subtype 6B was isolated from blood cultures on each occasion. He was treated with i.v. cephalosporins, as the organisms were resistant to penicillin with a minimum inhibitory concentration (MIC) of 2.0, and there was complete resolution of symptoms each time. In the light of recurrent sepsis with this penicillin-resistant organism the decision was made to give prophylactic levofloxacin for the next 12 months. This case illustrates that the choice of prophylactic regimen and the treatment of sepsis in immunocompromised patients remain difficult and challenging issues.

High-hyperdiploidy in Philadelphia positive adult acute lymphoblastic leukaemia: case-series and review of literature.

Patients with Philadelphia positive (Ph(+)) adult acute lymphoblastic leukaemia (ALL) have a poor prognosis. Stem cell transplantation (SCT) is increasingly being recognised as the treatment of choice in eligible patients with Ph(+)ALL, but disease-relapse remains a problem in a proportion of patients prior to and after SCT. Genetic abnormalities in addition to the Ph chromosome may influence the biology and clinical course of ALL, but there are not many studies on the potential genetic heterogeneity of adult Ph(+)ALL and clinical outcomes. Here, we report on five patients with ALL who were double Ph(+) and also had a high-hyperdiploid karyotype (Ph(+)/hyperdiploid) at diagnosis. In contrast to the presence of the Ph(+) chromosome, high-hyperdiploidy (>50 chromosomes) as the sole karyotypic abnormality in ALL is associated with a favourable clinical outcome. In our series, four patients with a Ph(+)/hyperdiploid karyotype achieved a cytogenetic remission after induction chemotherapy and proceeded to stem cell transplantation (SCT). The fifth had five subclones including Ph(+)/hyperdiploid, as well as those that were only Ph(+); the latter emerged as the dominant clone after induction therapy and the patient died of disease-relapse. Of the patients who underwent SCT, only one relapsed, but achieved a durable remission with donor lymphocyte infusions. Thus, it is conceivable that the presence of high-hyperdiploidy as an additional karyotypic abnormality may confer a better prognosis to Ph(+)ALL, presumably by altering the kinetics of Ph(+) neoplastic cells. We have discussed these results in the context of recent studies on the significance of high-hyperdiploidy in Ph(+) adult ALL.

Recovery of renal function after autologous stem cell transplantation in myeloma patients with end-stage renal failure.

The disease-free survival of patients with myeloma and severe renal failure after high-dose melphalan and autologous stem cell rescue is similar to those with normal renal function at the time of the autograft. However, recovery of renal function after intensive treatment is uncommon and patients with end-stage renal failure continue to be dialysis-dependent. We report two patients with myeloma who required regular haemodialysis from diagnosis, but became dialysis-independent after a high-dose melphalan autograft. Thus, in some patients, renal function may be partially salvageable despite the requirement for dialysis at the time of autografting.

Stem cell transplantation after salvage therapy with high-dose cytarabine and amsacrine in adults with high-risk leukaemia.

Stem cell transplantation (SCT) may be the only curative option for patients with relapsed or refractory leukaemia, that is, high-risk (HR) leukaemia. Several salvage regimens have been used to cytoreduce disease before SCT, but disease progression or treatment toxicity limits numbers of patients receiving SCT. Here, we report our experience with high-dose cytarabine and amsacrine (Ara-amsa) to salvage patients with HR-leukaemia in the context of SCT. A total of 34 patients with HR-leukaemia (20 AML, 12 ALL, two advanced CML) received 3 g/m(2)/day cytarabine for 5 days and amsacrine 200 mg/m(2)/day for 3 days. Disease response was observed in 62% of patients. Toxicity was limited to neutropenic fever, one patient developed cerebellar toxicity and there was one treatment-related death. A total of 17 patients proceeded to SCT (12 allografts and five autografts). Median survival (OS) of all patients was 10.8 months (95% CI 7.8-21). Patients who were consolidated with SCT after salvage therapy had a superior median OS of 29.4 months (95% CI 12.5-upper limit not reached, n=17) than those who did not receive SCT (6.7 months, CI 1.5-8.6, P<0.0001). Median disease-free survival with SCT (23 months) was higher than after treatment with salvage chemotherapy alone (6.7 months, P=0.0002). Thus Ara-amsa can be used effectively to salvage HR-leukaemia, enabling further consolidation with SCT.

Post-transplant T cell chimerism predicts graft versus host disease but not disease relapse in patients undergoing an alemtuzumab based reduced intensity conditioned allogeneic transplant.

In this multicentre retrospective study we have studied the impact of T cell chimerism on the outcome of 133 patients undergoing an alemtuzumab based reduced intensity conditioning allograft (RIC). The median age of the patients was 50 years (range 42-55 years). 77 patients were transplanted using an HLA identical sibling donor while 56 patients received a fully matched volunteer unrelated donor graft. 64 patients had a lymphoid malignancy and 69 were transplanted for a myeloid malignancy. 38 patients (29%) relapsed with no significant difference in risk of relapse between patients developing full donor and mixed donor chimerism in the T-cell compartment on D+90 and D+180 post transplant. Day 90 full donor T cell chimerism correlated with an increased incidence of acute GVHD according to NIH criteria (p=0.0004) and the subsequent development of chronic GVHD. Consistent with previous observations, our results confirmed a correlation between the establishment of T cell full donor chimerism and acute GVHD in T deplete RIC allografts. However our study failed to identify any correlation between T cell chimerism and relapse risk and challenge the use of pre-emptive donor lymphocyte infusions (DLI) in patients with mixed T cell chimerism transplanted using an alemtuzumab based RIC regimen.

Multifocal primary extranodal B-cell non-Hodgkin's lymphoma involving six extranodal sites.

An unusual case of Epstein-Barr virus-negative primary extranodal B-cell non-Hodgkin's lymphoma involving six anatomical sites is described in a report that challenges the role of organotropism in the pathogenesis of extranodal lymphoma.

Autoimmune pancytopenia following combination chemotherapy for chronic lymphocytic leukaemia.

Autoimmune haemolysis or thrombocytopenia can complicate purine nucleoside monotherapy for chronic lymphocytic leukaemia (CLL), but Evans syndrome is rare. This is a report of the occurrence of pancytopenia secondary to a unique combination of red cell aplasia with autoimmune thrombocytopenia and neutropenia in a patient with CLL following treatment with fludarabine and cyclophosphamide. This case is unusual for the simultaneous targeting of three haemopoietic lineages by immune dysfunction following fludarabine and cyclophosphamide, which is a treatment regimen believed to reduce autoimmune haematological toxicity in CLL.