Identification of somatic JAK1 mutations in patients with acute myeloid leukemia

Somatic mutations in JAK2 are frequently found in myeloproliferative diseases, and gain-of-function JAK3 alleles have been identified in M7 acute myeloid leukemia (AML), but a role for JAK1 in AML has not been described. We screened the entire coding region of JAK1 by total exonic resequencing of bone marrow DNA samples from 94 patients with de novo AML. We identified 2 novel somatic mutations in highly conserved residues of the JAK1 gene (T478S, V623A), in 2 separate patients and confirmed these by resequencing germ line DNA samples from the same patients. Overexpression of mutant JAK1 did not transform primary murine cells in standard assays, but compared with wild-type JAK1, JAK1^T478S, and JAK1^V623A expression was associated with increased STAT1 activation in response to type I interferon and activation of multiple downstream signaling pathways. This is the first report to demonstrate somatic JAK1 mutations in AML and suggests that JAK1 mutations may function as disease-modifying mutations in AML pathogenesis.     

Exploring the utility of whole‐exome sequencing as a diagnostic tool in a child with atypical episodic muscle weakness

The advent of whole‐exome next‐generation sequencing (WES) has been pivotal for the molecular characterization of Mendelian disease; however, the clinical applicability of WES has remained relatively unexplored. We describe our exploration of WES as a diagnostic tool in a 3½‐year old female patient with a 2‐year history of episodic muscle weakness and paroxysmal dystonia who presented following a previous extensive but unrevealing diagnostic work‐up. WES was performed on the proband and her two parents. Parental exome data was used to filter potential de novo genomic events in the proband and suspected variants were confirmed using di‐deoxy sequencing. WES revealed a de novo non‐synonymous mutation in exon 21 of the calcium channel gene CACNA1S that has been previously reported in a single patient as a rare cause of atypical hypokalemic periodic paralysis. This was unexpected, as the proband's original differential diagnosis had included hypokalemic periodic paralysis, but clinical and laboratory features were equivocal, and standard clinical molecular testing for hypokalemic periodic paralysis and related disorders was negative. This report highlights the potential diagnostic utility of WES in clinical practice, with implications for the approach to similar diagnostic dilemmas in the future.     

Fractography and oxidative analysis of gamma inert sterilized posterior-stabilized tibial insert post fractures: Report of two cases

BackgroundHighly crosslinked ultra-high molecular weight polyethylene (UHMWPE) has shown success in reducing wear in hip arthroplasty but there remains skepticism about its use in Total Knee Replacement (TKR) inserts that are known to experience fatigue loading and higher local cyclic contact stresses.MethodsTwo Legacy Posterior-Stabilized (LPS) Zimmer NexGen tibial implants sterilized by gamma irradiation in an inert environment with posts that fractured in vivo were analyzed. Failure mechanisms were determined using optical and scanning electron microscopy along with oxidative analysis via Fourier Transform Infra-Red (FTIR) spectroscopy.ResultsMicrographs of one retrieval revealed fatigue crack initiation on opposite sides of the post and quasi-brittle micromechanisms of crack propagation. FTIR of this retrieval revealed no oxidation. The fracture surface image of the second retrieval indicated a brittle fracture process and FTIR revealed oxidation in the explant.ConclusionsThese two cases suggest that crosslinking of UHMWPE as a manufacturing process or sterilization method in conjunction with designs that incorporate high stress concentrations, such as the tibial post, may reduce material strength. Moreover, free radicals generated from ionizing radiation can render the polymer susceptible to oxidative embrittlement.Clinical relevanceOur findings suggest that tibial post fractures may be the results of in vivo oxidation and low level crosslinking. These and previous reports of fractured crosslinked UHMWPE devices implores caution when used with high stress concentrations, particularly when considering the potential for in vivo oxidation in TKR.     

Development of an instrument for the identification of frail older people as a target population for integrated care

Background

Primary care is increasingly interested in the identification of frailty, as it selects the target population for integrated care. However, instruments for the identification of frailty specifically validated for use in primary care are scarce. This study developed the Easycare Two-step Older persons Screening (Easycare-TOS), which provides a valid, efficient, and pragmatic screening procedure to identify frail older people.

Aim

This paper aims to describe the development of the Easycare-TOS and the data from the pilot studies.

Design and setting

Observational pilot study in seven academic GP practices in and around Nijmegen, The Netherlands.

Method

The Easycare-TOS was developed in a cyclic process with the input of stakeholders. In every cycle, the requirements were first defined, then translated into a prototype that was tested in a pilot study. The Easycare-TOS makes optimal use of prior knowledge of the GP, and the professionals’ appraisal is decisive in the frailty decision, instead of a cut-off score. Further, it considers aspects of frailty, as well as aspects of the care context of the patient.

Results

The pilot data have shown that after step 1, two-thirds of the patients do not need further assessment, because they are judged as not frail, based on prior knowledge of the GP. The overall prevalence of frailty in this pilot study is 24%. Most professionals who participated in the pilot studies considered the time investment acceptable and the method to be of added value.

Conclusion

The Easycare-TOS instrument meets the predefined efficiency, flexibility, and acceptability requirements for use as an identification instrument for frailty in primary care.     

PD1 expression and correlation with its ligands in oral cancer specimens and peripheral blood

ObjectivesThis study analyzed the expression of the PD1 receptor in tumor tissue and peripheral blood of oral squamous cell carcinoma (OSCC) patients, and correlated it with the PD1 ligands PD-L1 and PD-L2. The currently low response rates of checkpoint inhibitor treatment in OSCC could be increased by a better understanding of immune checkpoint biology. Despite evidence in the literature for upregulation of PD1 checkpoint ligands in OSCC tissue, there has been no correlation analysis of the PD1 receptor with its ligands in tissue specimens and peripheral blood of OSCC patients.Materials and methodsAn RT-qPCR analysis of PD1 mRNA expression was performed in oral cancer specimens, healthy mucosa, and corresponding blood samples. A cut-off point (COP) was determined and a chi-square (χ²) test was carried out. PD1 expression was correlated with previously reported PD-L1 and PD-L2 expression values using the Spearman test.ResultsTissue and blood specimens of 48 OSCC patients and 26 healthy individuals were analyzed. PD1 expression in OSCC specimens was significantly increased (p = 0.006) compared with healthy oral mucosa. PD1 overexpression in tissue samples showed a significant association with the presence of malignancy (p = 0.006). PD1 expression in tissue samples showed a significant positive correlation (p < 0.001) with the ligands PD-L1 and PD-L2. In contrast, there was no correlation between PD1 and its ligands in blood samples. However, there was a significant positive correlation (p < 0.001) between the ligands PD-L1 and PD-L2, both in tissue and blood samples.ConclusionsIncreased PD1 expression might be a manifestation of T-cell exhaustion in OSCC specimens, leading to immune tolerance. PD-L1/PD-L2-PD1 interaction may be a major mediator of local immunosuppression in OSCC, requiring advanced multimodal treatment protocols.     

Autologous bone marrow transplantation for acute myeloid leukemia using busulfan plus etoposide as a preparative regimen

We have studied the use of a new preparative regimen for the treatment of patients in remission of acute myeloid leukemia (AML) with autologous bone marrow transplantation. Chemotherapy consisted of busulfan 1 mg/kg every 6 hours for 4 days (total dose, 16 mg/kg) on days -7 through -4 followed by an intravenous infusion over 6 to 10 hours of etoposide 60 mg/kg on day -3. Autologous bone marrow, treated in vitro with 100 micrograms/mL of 4-hydroperoxycyclophosphamide, was infused on day 0. We have treated 58 patients up to the age of 60 years, 32 in first remission, 21 in second or third remission, and 5 with primary refractory AML unresponsive to high-dose Ara-C, but achieving remission with aggressive salvage regimens. Of the first remission patients, there has been 1 treatment related death and 5 relapses. With median follow-up of 22 months, the actuarial relapse rate is 22% +/- 9% and disease-free survival is 76% +/- 9% at 3 years. Patients with favorable French-American-British (FAB) subtypes (M3 or M4 EO) did especially well, with no relapses seen in 15 patients observed for a median of 30 months. Actuarial relapse rate at 3 years was 48% for first remission patients with less favorable FAB subtypes. Of patients in second or third remission, there were 5 treatment related deaths and 4 relapses. With median follow-up of 22 months, the actuarial relapse rate is 25% +/- 11% and disease-free survival is 56% +/- 11% at 3 years. Four of five primary refractory patients died during treatment and 1 remains in remission with short follow-up. These preliminary data are very encouraging and, if confirmed, support the use of autologous purged bone marrow transplantation using aggressive preparative regimens as one approach to improve the outcome of adults with AML.