COVID-19 outcomes in haemopoietic stem cell transplant recipients in Western Australia: the value of vaccination and antiviral therapy.

Coronavirus-19 (COVID-19) mortality rates among haemopoietic stem cell transplant (HSCT) patients are high, ranging between 20% and 40%. We prospectively evaluated the mortality outcomes of COVID-19 in Western Australian HSCT patients. A total of 32/492 (6.5%) HSCT recipients contracted COVID-19 during the study, of whom 30/32 (94%) developed mild or asymptomatic disease. Two allogeneic HSCT patients were hospitalised for severe COVID-19; one patient died. Stringent healthcare, social isolation practices, aggressive vaccination programmes and rapid access to COVID-19 antivirals may have promoted mild COVID-19 illness in Western Australian HSCT patients, resulting in one of the lowest COVID-19 mortality rates in HSCT recipients worldwide.

Letermovir for pre-emptive cytomegalovirus therapy after allogeneic hematopoietic cell transplantation.

BACKGROUND: Cytomegalovirus (CMV) is a common cause of morbidity after allogeneic haematopoietic cell transplantation (alloHCT). Pre-emptive therapy (PET) with valganciclovir (VGC) is associated with haematological toxicity. METHODS: We included alloHCT patients from 2018 to 2021 where letermovir (LTV) was used for CMV PET because of cytopenias. RESULTS: Ten patients were included. Six received VGC prior to LTV. VGC was commenced at median d42, given for median 40 days. LTV was commenced at median d90, given for median 54 days. At commencement of antiviral, CMV viral load was higher for VGC at 3.7 log10 IU/mL, compared to LTV at 2.9 log10 IU/mL. Viral load reduction occurred at 0.18 log10 IU/mL per week for VGC, compared to 0.17 log10 IU/mL per week for LTV. There was no clinically significant CMV viremia after stopping LTV. Cytopenias improved on LTV. CONCLUSION: LTV was effective in controlling CMV viremia when it was given at a lower starting CMV viral load and later post alloHCT than VGC. Further study is required of LTV as upfront PET following alloHCT.

Ibrutinib for First-Line Treatment of Chronic Graft-Versus-Host Disease: Results From the Randomized Phase III iNTEGRATE Study.

PURPOSE: To present primary and final analyses from the randomized, double-blind, placebo-controlled, phase III iNTEGRATE study, which evaluated the safety and efficacy of ibrutinib with prednisone in previously untreated patients with chronic graft-versus-host disease (cGVHD). METHODS: Patients (age ≥ 12 years) with newly diagnosed moderate or severe cGVHD, requiring systemic corticosteroid therapy, and with no prior systemic treatment for cGVHD were randomly assigned 1:1 to receive ibrutinib 420 mg once daily plus prednisone, starting at 1 mg/kg once daily or placebo plus prednisone. The primary end point was response rate at 48 weeks according to 2014 National Institutes of Health Consensus Development Project Criteria. Other end points included event-free survival, duration of response, time to withdrawal of immunosuppressants, improvement in Lee cGVHD Symptom Scale score, overall survival (OS), and safety. RESULTS: Ninety-five and 98 patients enrolled in the ibrutinib-prednisone and placebo-prednisone arms, respectively. At 48 weeks, response rates were 41% (ibrutinib-prednisone) and 37% (placebo-prednisone; P = .54). At 33 months of follow-up, median duration of response was 19 months (ibrutinib-prednisone) and 10 months (placebo-prednisone; P = .10). Median event-free survival was 15 months (ibrutinib-prednisone) and 8 months (placebo-prednisone; hazard ratio, 0.76; 95% CI, 0.54 to 1.1; P = .11). Improvement in overall Lee cGVHD Symptom Scale was 43% (ibrutinib-prednisone) and 31% (placebo-ibrutinib; P = .07). Median OS was not reached in either arm. The 24-month Kaplan-Meier OS estimates were 80% for both arms (hazard ratio, 1.06; 95% CI, 0.59 to 1.90). Grade ≥ 3 serious adverse events occurred in 49% (ibrutinib-prednisone) and 47% (placebo-prednisone) of patients. CONCLUSION: There was no statistical difference observed in the primary and secondary end points with ibrutinib-prednisone treatment. No new safety signals were observed with ibrutinib treatment in previously untreated patients with cGVHD. The primary end point of iNTEGRATE was not met.

Temporal continuity shapes visual responses of macaque face patch neurons.

Macaque inferior temporal cortex neurons respond selectively to complex visual images, with recent work showing that they are also entrained reliably by the evolving content of natural movies. To what extent does temporal continuity itself shape the responses of high-level visual neurons? We addressed this question by measuring how cells in face-selective regions of the macaque visual cortex were affected by the manipulation of a movie's temporal structure. Sampling a 5-min movie at 1 s intervals, we measured neural responses to randomized, brief stimuli of different lengths, ranging from 800 ms dynamic movie snippets to 100 ms static frames. We found that the disruption of temporal continuity strongly altered neural response profiles, particularly in the early response period after stimulus onset. The results suggest that models of visual system function based on discrete and randomized visual presentations may not translate well to the brain's natural modes of operation.

Genetically encoded fluorescent sensors for imaging neuronal dynamics in vivo.

The brain relies on many forms of dynamic activities in individual neurons, from synaptic transmission to electrical activity and intracellular signaling events. Monitoring these neuronal activities with high spatiotemporal resolution in the context of animal behavior is a necessary step to achieve a mechanistic understanding of brain function. With the rapid development and dissemination of highly optimized genetically encoded fluorescent sensors, a growing number of brain activities can now be visualized in vivo. To date, cellular calcium imaging, which has been largely used as a proxy for electrical activity, has become a mainstay in systems neuroscience. While challenges remain, voltage imaging of neural populations is now possible. In addition, it is becoming increasingly practical to image over half a dozen neurotransmitters, as well as certain intracellular signaling and metabolic activities. These new capabilities enable neuroscientists to test previously unattainable hypotheses and questions. This review summarizes recent progress in the development and delivery of genetically encoded fluorescent sensors, and highlights example applications in the context of in vivo imaging.

A complex case of necrobiotic xanthogranuloma with IgG-kappa paraproteinemia: Disease regression achieved with melphalan and prednisone combination therapy.

Necrobiotic xanthogranuloma (NXG) is a rare dermatosis that is often associated with monoclonal paraproteinemia and hematological malignancies. We report the rare case of an 84-year-old gentleman with extensive truncal NXG and IgG-kappa paraproteinemia who achieved significant disease regression following six cycles of combination melphalan/prednisone therapy.

Locomotion activates PKA through dopamine and adenosine in striatal neurons.

The canonical model of striatal function predicts that animal locomotion is associated with the opposing regulation of protein kinase A (PKA) in direct and indirect pathway striatal spiny projection neurons (SPNs) by dopamine1-7. However, the precise dynamics of PKA in dorsolateral SPNs during locomotion remain to be determined. It is also unclear whether other neuromodulators are involved. Here we show that PKA activity in both types of SPNs is essential for normal locomotion. Using two-photon fluorescence lifetime imaging8-10 of a PKA sensor10 through gradient index lenses, we measured PKA activity within individual SPNs of the mouse dorsolateral striatum during locomotion. Consistent with the canonical view, dopamine activated PKA activity in direct pathway SPNs during locomotion through the dopamine D1 receptor. However, indirect pathway SPNs exhibited a greater increase in PKA activity, which was largely abolished through the blockade of adenosine A2A receptors. In agreement with these results, fibre photometry measurements of an adenosine sensor11 revealed an acute increase in extracellular adenosine during locomotion. Functionally, antagonism of dopamine or adenosine receptors resulted in distinct changes in SPN PKA activity, neuronal activity and locomotion. Together, our results suggest that acute adenosine accumulation interplays with dopamine release to orchestrate PKA activity in SPNs and proper striatal function during animal locomotion.

High incidence of minor and micro breakpoints in Chronic Myeloid Leukaemia with additional cytogenetic abnormalities at diagnosis - the Western Australian series.

Introduction and objective: Chronic Myeloid Leukaemia (CML) is defined by the presence of the Philadelphia chromosome, a balanced translocation between chromosomes 9 and 22 that results in the constitutively active tyrosine kinase, BCR-ABL1. Additional chromosomal abnormalities (ACAs) at diagnosis occur in 5-10% of CML patients, and are important for prognosis. They are classified as major or minor route. The purpose of our study was to determine the frequency and type of ACAs in 193 newly diagnosed CML patients, and to evaluate patient characteristics, treatment response, and survival. Methods: Medical records, in conjunction with data from the PathWest cytogenetics and molecular laboratories, were analysed. Results: ACAs were present in 14 (7.3%) of patients at diagnosis. Seven patients had major-route abnormalities, with additional chromosome 8 (+8) the most common. All patients were treated with tyrosine kinase inhibitors (TKIs). Three patients presented in blast crisis; two patients have died. Of note, there was a high incidence of the rare minor and micro BCR-ABL1 fusion transcripts. Conclusions: Frequency of ACAs at diagnosis was similar to that of previous reports. These patients consist a higher-risk cohort, and require individualised treatment, with consideration of frontline and secondary TKIs, adjunct chemotherapy, novel agents, and allogeneic stem cell transplant.

Perceptual Weighting of V1 Spikes Revealed by Optogenetic White Noise Stimulation.

During visually guided behaviors, mere hundreds of milliseconds can elapse between a sensory input and its associated behavioral response. How spikes occurring at different times are integrated to drive perception and action remains poorly understood. We delivered random trains of optogenetic stimulation (white noise) to excite inhibitory interneurons in V1 of mice of both sexes while they performed a visual detection task. We then performed a reverse correlation analysis on the optogenetic stimuli to generate a neuronal-behavioral kernel, an unbiased, temporally precise estimate of how suppression of V1 spiking at different moments around the onset of a visual stimulus affects detection of that stimulus. Electrophysiological recordings enabled us to capture the effects of optogenetic stimuli on V1 responsivity and revealed that the earliest stimulus-evoked spikes are preferentially weighted for guiding behavior. These data demonstrate that white noise optogenetic stimulation is a powerful tool for understanding how patterns of spiking in neuronal populations are decoded in generating perception and action.SIGNIFICANCE STATEMENT During visually guided actions, continuous chains of neurons connect our retinas to our motoneurons. To unravel circuit contributions to behavior, it is crucial to establish the relative functional position(s) that different neural structures occupy in processing and relaying the signals that support rapid, precise responses. To address this question, we randomly inhibited activity in mouse V1 throughout the stimulus-response cycle while the animals did many repetitions of a visual task. The period that led to impaired performance corresponded to the earliest stimulus-driven response in V1, with no effect of inhibition immediately before or during late stages of the stimulus-driven response. This approach offers experimenters a powerful method for uncovering the temporal weighting of spikes from stimulus to response.

QuantiFERON-cytomegalovirus to predict clinically significant cytomegalovirus infection after allogeneic hematopoietic stem cell transplantation.

BACKGROUND: Controlling cytomegalovirus (CMV) infection through prophylaxis or pre-emptive therapy remains an important contributor to outcomes after allogeneic hematopoetic stem cell transplant (alloHCT). Predicting clinically significant CMV infection (csCMVi) after day 100 remains a challenge. METHODS: We examined the abilty of the QuantiFERON-CMV assay (QFN-CMV) at day 100 (d100) and day 150 (d150) after alloHCT to predict csCMVi after these time points, with median follow-up of 3.1 years (range 1.3-4.3 years). RESULTS: In 46 transplants (donor seropositive (D+) recipient seronegative (R-) = 12, D+R+ = 25, D-R+ = 9; matched related = 13, unrelated donor = 32, haploidentical = 1), for the prediction of freedom from csCMVi >d100, QFN-CMVd100 (positive compared to negative/indeterminate) had sensitivity 62% (23/37), specificity 100% (9/9), positive predictive value 100% (23/23), and negative predictive value 39% (9/23). For the prediction of freedom from csCMVi >d150, QFN-CMVd150 (positive compared to negative/indeterminate) had sensitivity 62% (18/29), specificity 83% (5/6), positive predictive value 95% (18/19), and negative predictive value 31% (5/16). CONCLUSION: Positive QFN-CMV at d100 and d150 strongly predicted freedom from csCMVi after these time points. QFN-CMV could be utilized to predict the need for pre-emptive therapy and CMV viral load monitoring after day 100 post-alloHCT.

Evaluating the Efficacy, Toxicity and Pharmacokinetic Profile of Oral Busulfan in Allogeneic Stem Cell Transplant Patients.

Background: Oral busulfan and intravenous cyclophosphamide (Bu/Cy) are common myeloablative preparations used in allogeneic hematopoietic stem cell transplantation (HSCT). Herein, we investigated the safety of (Bu/Cy) administration during HSCT. Methods: Patients administered Bu/Cy for allogeneic HSCT at Royal Perth Hospital and Fiona Stanley Hospital between 2007 and 2017 were reviewed for inclusion in the study. We performed busulfan pharmacokinetic (PK) testing for a subset of patients and allometric scaling modeling to assess the best method of busulfan dosing in patients at extremes of weight. Results: Sixty-nine patients were included in the clinical outcome analysis. The median follow-up period was 32 months (range, 9-114 months). The three-year overall survival rate was 62% (95% confidence interval (CI), 51%-75%), and transplant-related mortality was 4% at 6 months (95% CI, 1-7%), with a low rate of sinusoidal obstruction syndrome of the liver being observed. In addition, relapse was 38% (95% CI, 30%-44%) at 3 years. The PK information of 15 patients receiving busulfan was available after oral dosing. The average per-dose busulfan exposure was 1,350 µmol.min/L (range, 878-1,717 µmol.min/L), and the within target range was 1,000-1,500 µmol.min/L in 73% of patients. Of the size measures investigated, ideal and adjusted body weight (ABW40) provided the best fit. No association was observed between busulfan exposure, toxicity, and relapse. Conclusions: Overall, Bu/Cy administration appeared safe when dosed in relation to weight, showing a low early transplant-related mortality rate following adequate busulfan exposure in majority of the cases. Body size measures, such as ideal body weight or ABW40, are likely more suitable for use during busulfan dosing, particularly at high extremes of the body mass index classification.

Novel lysine-specific histone demethylase 1 inhibitor in acute myeloid leukaemia transformed from essential thrombocythaemia.

BACKGROUND: While progress continues in the understanding of molecular abnormalities in acute myeloid leukaemia (AML), with some specific targeted therapies now available, it remains commonly fatal in the elderly. Leukaemic evolution and transformation from myeloproliferative neoplasms (MPN) may be associated with increased numbers of mutations in the genes associated with myeloid neoplasm and the prognosis in such patients is invariably dismal. Targeting of intracellular enzymes associated with integral cellular function has advanced understanding and promises improvements in treatments. CASE: We report impressive prolonged response to therapy in a case of secondary AML, arising from essential thrombocythaemia (ET). The trial agent, the oral lysine-specific histone demethylase 1 (LSD1) inhibitor Bomedemstat (IMG-7289) was well tolerated. In addition to suppressing the malignant clone, these blasts showed differentiation to monocytes morphologically as well as by surface markers seen on flow cytometry. Bomedemstat has efficacy in the treatment of myelofibrosis and may have a special role in treatment of specific AML subtypes, including secondary leukaemias arising from MPN as seen. CONCLUSION: We report a case of an older adult with secondary AML transformed from ET, with a remarkable response to LSD1 inhibition with Bomedemstat, with prolonged reduction in blasts demonstrating differentiation to monocytes.

Genetically encoded sensors towards imaging cAMP and PKA activity in vivo.

Cyclic adenosine monophosphate (cAMP) is a universal second messenger that plays a crucial role in diverse biological functions, ranging from transcription to neuronal plasticity, and from development to learning and memory. In the nervous system, cAMP integrates inputs from many neuromodulators across a wide range of timescales - from seconds to hours - to modulate neuronal excitability and plasticity in brain circuits during different animal behavioral states. cAMP signaling events are both cell-specific and subcellularly compartmentalized. The same stimulus may result in different, sometimes opposite, cAMP dynamics in different cells or subcellular compartments. Additionally, the activity of protein kinase A (PKA), a major cAMP effector, is also spatiotemporally regulated. For these reasons, many laboratories have made great strides toward visualizing the intracellular dynamics of cAMP and PKA. To date, more than 80 genetically encoded sensors, including original and improved variants, have been published. It is starting to become possible to visualize cAMP and PKA signaling events in vivo, which is required to study behaviorally relevant cAMP/PKA signaling mechanisms. Despite significant progress, further developments are needed to enhance the signal-to-noise ratio and practical utility of these sensors. This review summarizes the recent advances and challenges in genetically encoded cAMP and PKA sensors with an emphasis on in vivo imaging in the brain during behavior.

High dose valaciclovir to prevent cytomegalovirus infection in allogeneic haematopoietic stem cell transplant recipients.

Cytomegalovirus (CMV) infection causes morbidity and mortality after allogeneic haematopoietic stem cell transplantation (HSCT). We investigated whether prophylaxis with high dose valaciclovir is effective at reducing the incidence of clinically significant CMV infection (csCMVi) within six months of allogeneic HSCT. Consecutive allogeneic HSCT recipients who received 2g valaciclovir orally four times daily from transplant until day 100 (prophylaxis group) were compared to subsequent patients who received no CMV prophylaxis (control group). Forty-nine patients in the prophylaxis group and 59 in the control group were included. The cumulative incidence of csCMVi at 6 months was 20% (95% confidence interval (CI): 9%-27%) in the prophylaxis group and 39% (95% CI: 26%-47%) in the control group (P = .009). There was no CMV disease in the prophylaxis group and three cases in the control group. There was no difference in time to neutrophil or platelet recovery nor graft failure between groups. On multivariable analysis, lack of high dose valaciclovir prophylaxis, positive recipient CMV IgG and age were associated with greater likelihood of csCMVi. There was no significant difference in acute graft versus host disease, non-relapse mortality or overall survival between groups. In this retrospective cohort study, high dose valaciclovir prophylaxis resulted in a lower incidence of csCMVi within six months of HSCT.

Combined chronic myeloid leukaemia and chronic lymphocytic leukaemia in five patients, including one with 17p deletion.

We report a series of five Australian cases of chronic lymphocytic leukaemia (CLL) occurring concurrently with chronic myeloid leukaemia (CML). Patient management including therapies and response together with clinical progress was obtained from medical records and laboratory information systems. Prior to CML diagnosis, all five had a preceding diagnosis of CLL. Three had received prior fludarabine. All received tyrosine kinase inhibitors (TKI). None required subsequent therapy for CLL. One patient had 17p deletion CLL and another patient had normal CLL cytogenetics. All currently have satisfactory blood counts with quantitative polymerase chain reaction for CML showing molecular response. All remain alive. Thus, such cases can be successfully managed by treating each haematological disorder in the usual manner. The control achieved in CML with the TKI enables satisfactory marrow function to recover in patients with concomitant CLL. The role for allograft in patients with dual malignancies is uncertain and needs to be individualised depending on control of each malignancy.

A phase 3 double-blind study of the addition of tocilizumab vs placebo to cyclosporin/methotrexate GVHD prophylaxis.

We determined the efficacy of tocilizumab (TCZ) in preventing grade 2-4 acute graft-versus-host disease (aGVHD) in patients with acute leukemia or myelodysplasia undergoing matched sibling donor (MSD) or volunteer unrelated donor (VUD) allogeneic stem cell transplantation after myeloablative or reduced-intensity conditioning across 5 Australian centers. A total of 145 patients (50 MSD, 95 VUD) were randomly assigned to placebo or TCZ on day -1. All patients received T-cell-replete peripheral blood stem cell grafts and graft-versus-host disease (GVHD) prophylaxis with cyclosporin/methotrexate. A planned substudy analyzed the VUD cohort. With a median follow-up of 746 days, the incidence of grade 2-4 aGVHD at day 100 for the entire cohort was 36% for placebo vs 27% for TCZ (hazard ratio [HR], 0.69; 95% confidence interval [CI], 0.38-1.26; P = .23) and 45% vs 32% (HR, 0.61; 95% CI, 0.31-1.22; P = .16) for the VUD subgroup. The incidence of grade 2-4 aGVHD at day 180 for the entire cohort was 40% for placebo vs 29% for TCZ (HR, 0.68; 95% CI, 0.38-1.22; P = .19) and 48% vs 32% (HR, 0.59; 95% CI, 0.30-1.16; P = .13) for the VUD subgroup. Reductions in aGVHD were predominantly in grade 2 disease. For the entire cohort, transplant-related mortality occurred in 8% vs 11% of placebo-treated vs TCZ-treated patients, respectively (P = .56), and overall survival was 79% vs 71% (P = .27). Median day to neutrophil and platelet engraftment was delayed by 2 to 3 days in TCZ-treated patients, whereas liver toxicity and infectious complications were similar between groups. In this phase 3 randomized double-blind trial, TCZ showed nonsignificant trends toward reduced incidence of grade 2-4 aGVHD in recipients from HLA-matched VUDs but no improvements in long term-survival.

RUNX1-mutated families show phenotype heterogeneity and a somatic mutation profile unique to germline predisposed AML.

First reported in 1999, germline runt-related transcription factor 1 (RUNX1) mutations are a well-established cause of familial platelet disorder with predisposition to myeloid malignancy (FPD-MM). We present the clinical phenotypes and genetic mutations detected in 10 novel RUNX1-mutated FPD-MM families. Genomic analyses on these families detected 2 partial gene deletions, 3 novel mutations, and 5 recurrent mutations as the germline RUNX1 alterations leading to FPD-MM. Combining genomic data from the families reported herein with aggregated published data sets resulted in 130 germline RUNX1 families, which allowed us to investigate whether specific germline mutation characteristics (type, location) could explain the large phenotypic heterogeneity between patients with familial platelet disorder and different HMs. Comparing the somatic mutational signatures between the available familial (n = 35) and published sporadic (n = 137) RUNX1-mutated AML patients showed enrichment for somatic mutations affecting the second RUNX1 allele and GATA2. Conversely, we observed a decreased number of somatic mutations affecting NRAS, SRSF2, and DNMT3A and the collective genes associated with CHIP and epigenetic regulation. This is the largest aggregation and analysis of germline RUNX1 mutations performed to date, providing a unique opportunity to examine the factors underlying phenotypic differences and disease progression from FPD to MM.