Treatment outcomes of T and natural-killer/T-cell lymphoma with ifosfamide, carboplatin and etoposide chemotherapy

BACKGROUND

Contemporary data of peripheral T-cell lymphoma (PTCL) and natural-killer/T-cell lymphoma (NKTL) patients treated with ifosfamide, carboplatin and etoposide (ICE) are limited.

AIMS

We performed a retrospective analysis to estimate outcomes of ICE-treated PTCL and NKTL patients at three tertiary cancer centres in Singapore.

METHODS AND RESULTS

Patients were identified through lymphoma databases from National Cancer Centre Singapore (NCCS), National University Hospital, Singapore (NUHS), and Singapore General Hospital (SGH). Responses and survival outcomes were determined from electronic medical records. A total of 75 patients with a median age of 50 were included. ICE was used as first-line treatment in 14 patients (19%) and as subsequent lines of treatment in 61 patients (81%). The overall response rates (ORR) for all patients was 63% (40% complete response [CR]). The ORR and CR in the first line were 86% and 64% respectively. At a median follow-up duration of 71.0 months, the median progression-free (PFS) and overall survival (OS) for all patients were 4.4 months (95%CI, 2.7-6.0) and 16 months (95%CI, 8.3-45.4) respectively.

CONCLUSION

In summary, ICE showed high ORR but poor PFS in relapsed/refractory PTCL and NKTL. ORR of ICE in the first line setting appears better than real-world CHOP data and warrants further study.

A phase 1 study of the safety, pharmacokinetics and pharmacodynamics of escalating doses followed by dose expansion of the selective inhibitor of nuclear export (SINE) selinexor in Asian patients with advanced or metastatic malignancies

Purpose:

This phase 1 study aims to evaluate the tolerability and the recommended phase 2 dose of selinexor in Asian patients with advanced or metastatic malignancies.

Experimental Design:

A total of 105 patients with advanced malignancies were enrolled from two sites in Singapore (National University Hospital and the National Cancer Centre, Singapore) from 24 February 2014 to 14 January 2019. We investigated four dosing schedules of selinexor in a 3 + 3 dose escalation design with an additional Phase 1b expansion cohort. Adverse events were graded with the NCI Common Terminology Criteria for Adverse Events v 4.03. Pharmacodynamic assessments included nuclear cytoplasmic localization of p27, XPO1 cargo proteins pre and post selinexor dosing and pharmacokinetic assessments were conducted at doses between 40 and 60 mg/m².

Results:

In our Asian patient cohort, dosing at 40 mg/m² given 2 out of 3 weeks, was the most tolerable for our patients. At this dose level, grade 3 adverse events included fatigue (8%), hyponatremia (23%), vomiting (5%), thrombocytopenia (5%), and anaemia (2%). Selinexor had a rapid oral absorption with median T_max of 2 h and no PK accumulation after multiple doses of tested regimens. Complete responses were seen in two lymphoma patients. Partial responses were noted in three diffuse large B cell lymphomas, one Hodgkin’s lymphoma and thymic carcinoma patient, respectively.

Conclusion:

Selinexor is tolerated by Asian patients at 40 mg/m² twice a week given 2 out of 3 weeks. A 1-week drug holiday was needed as our patients could not tolerate the current approved continuous dosing regimens because of persistent grade 3 fatigue, anorexia and hyponatremia.

Spike protein cleavage-activation mediated by the SARS-CoV-2 P681R mutation: a case-study from its first appearance in variant of interest (VOI) A.23.1 identified in Uganda

The African continent like all other parts of the world with high infection/low vaccination rates can, and will, be a source of novel SARS-CoV-2 variants. The A.23 viral lineage, characterized by three spike mutations F157L, V367F and Q613H, was first identified in COVID-19 cases from a Ugandan prison in July 2020, and then was identified in the general population with additional spike mutations (R102I, L141F, E484K and P681R) to comprise lineage A.23.1 by September 2020, with this virus being designated a variant of interest (VOI) in Africa and with subsequent spread to 26 other countries. The P681R spike substitution of the A.23.1 VOI is of note as it increases the number of basic residues in the sub-optimal SARS-CoV-2 spike protein furin cleavage site; as such, this substitution may affect viral replication, transmissibility or pathogenic properties. The same P681R substitution has also appeared in B.1.617 variants, including B.1.617.2 (Delta). Here, we performed assays using fluorogenic peptides mimicking the S1/S2 sequence from A.23.1 and B.1.617.2 and observed significantly increased cleavability with furin, compared to sequences derived from the original Wuhan-Hu1 S1/S2. We performed functional infectivity assays using pseudotyped MLV particles harboring SARS-CoV-2 spike proteins and observed an increase in transduction for A.23.1-pseudotyped particles compared to Wuhan-Hu-1 in Vero-TMPRSS2 and Calu-3 cells (with a presumed early entry pathway), although lowered infection in Vero E6 cells (with a presumed late entry pathway). However, these changes in infectivity were not reproduced in the original Wuhan-Hu-1 spike bearing only the P681R substitution. Our findings suggest that while A.23.1 has increased furin-mediated cleavage linked to the P681R substitution, which may affect viral infection and transmissibility, this substitution alone is not sufficient and needs to occur on the background of other spike protein changes to enable its full functional consequences.

Functional evaluation of the P681H mutation on the proteolytic activation of the SARS-CoV-2 variant B.1.1.7 (Alpha) spike

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the agent causing the COVID-19 pandemic. SARS-CoV-2 B.1.1.7 (Alpha), a WHO variant of concern first identified in the United Kingdom in late 2020, contains several mutations including P681H in the spike S1/S2 cleavage site, which is predicted to increase cleavage by furin, potentially impacting the viral cell entry. Here, we studied the role of the P681H mutation in B.1.1.7 cell entry. We performed assays using fluorogenic peptides mimicking the Wuhan-Hu-1 and B.1.1.7 S1/S2 sequence and observed no significant difference in furin cleavage. Functional assays using pseudoparticles harboring SARS-CoV-2 spikes and cell-to-cell fusion assays demonstrated no differences between Wuhan-Hu-1, B.1.1.7, or a P681H point mutant. Likewise, we observed no differences in viral growth between USA-WA1/2020 and a B.1.1.7 isolate in cell culture. Our findings suggest that, although the B.1.1.7 P681H mutation may slightly increase S1/S2 cleavage, this does not significantly impact viral entry or cell-cell spread.

Functional Infectious Nanoparticle Detector: Finding Viruses by Detecting Their Host Entry Functions Using Organic Bioelectronic Devices

Emerging viruses will continue to be a threat to human health and wellbeing into the foreseeable future. The COVID-19 pandemic revealed the necessity for rapid viral sensing and inhibitor screening in mitigating viral spread and impact. Here, we present a platform that uses a label-free electronic readout as well as a dual capability of optical (fluorescence) readout to sense the ability of a virus to bind and fuse with a host cell membrane, thereby sensing viral entry. This approach introduces a hitherto unseen level of specificity by distinguishing fusion-competent viruses from fusion-incompetent viruses. The ability to discern between competent and incompetent viruses means that this device could also be used for applications beyond detection, such as screening antiviral compounds for their ability to block virus entry mechanisms. Using optical means, we first demonstrate the ability to recapitulate the entry processes of influenza virus using a biomembrane containing the viral receptor that has been functionalized on a transparent organic bioelectronic device. Next, we detect virus membrane fusion, using the same, label-free devices. Using both reconstituted and native cell membranes as materials to functionalize organic bioelectronic devices, configured as electrodes and transistors, we measure changes in membrane properties when virus fusion is triggered by a pH drop, inducing hemagglutinin to undergo a conformational change that leads to membrane fusion.

Functional evaluation of the P681H mutation on the proteolytic activation the SARS-CoV-2 variant B.1.1.7 (Alpha) spike

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the agent causing the COVID-19 pandemic. SARS-CoV-2 B.1.1.7 (Alpha), a WHO variant of concern (VOC) first identified in the UK in late 2020, contains several mutations including P681H in the spike S1/S2 cleavage site, which is predicted to increase cleavage by furin, potentially impacting the viral cell entry. Here, we studied the role of the P681H mutation in B.1.1.7 cell entry. We performed assays using fluorogenic peptides mimicking the Wuhan-Hu-1 and B.1.1.7 S1/S2 sequence and observed no significant difference in furin cleavage. Functional assays using pseudoparticles harboring SARS-CoV-2 spikes and cell-to-cell fusion assays demonstrated no differences between Wuhan-Hu-1, B.1.1.7 or a P681H point mutant. Likewise, we observed no differences in viral growth between USA-WA1/2020 and a B.1.1.7 isolate in cell culture. Our findings suggest that while the B.1.1.7 P681H mutation may slightly increase S1/S2 cleavage this does not significantly impact viral entry or cell-cell spread.

Association between isolated diastolic hypertension and cardiovascular events: a systematic review and meta-analysis of prospective cohorts

Background

Isolated diastolic hypertension (IDH) is a subtype of hypertension, which is defined as systolic blood pressure (SBP) <140 mmHg and diastolic blood pressure (DBP) ≥90 mmHg by 2018 European Society of Cardiology (ESC) guideline and 2019 National Institute for Health and Care Excellent (NICE). Whereas some previous studies have demonstrated the significant association between IDH and cardiovascular (CV) events, some have not.

Purpose

To assess the association between IDH and the risk of CV events, CV mortality, and all-cause mortality.

Methods

We conducted a systematic search for publications using Medline, Embase, and the Cochrane Library from inception through March 2021 for prospective cohort studies exploring the association between IDH and CV events, CV mortality, and all-cause mortality. Relative risks (RR) or hazard ratios were extracted from the selected studies. Random effect models with inverse variance weighting were used to calculate the pooled RR and 95% confidence interval (CI). The primary outcome was a composite of total CV events including CV mortality. The secondary outcomes were CV mortality and all-cause mortality. We defined the IDH as SBP <140 mmHg and DBP ≥90 mmHg, reference group as BP less than 140/90mmHg.

Results

Overall, 15 studies were identified including 1049587 participants (5.5% IDH). For the primary outcome, IDH was significantly associated with risk of CV events (RR, 1.40 [95% CI, 1.18–1.66], p<0.001). The increased risk of CV events was also observed in subgroup analyses based on age (less or more than 50) and sex. However, in further stratified analysis based on geographical region, only the Asia population showed a significant association with increased risk of CV events, whereas results were null in Europe and North America populations. For the secondary outcomes, IDH was significantly associated with increased CV mortality (RR [95% CI], 1.41 [1.12–1.78], p<0.001) but not with all-cause mortality (RR [95% CI], 1.13 [0.86–1.48], p=0.378). The sensitivity analysis showed the overall results did not vary significantly after exclusion of any one study.

Conclusions

IDH is associated with increased risk of CV events and CV mortality. Further, more large-scale prospective epidemiological cohorts are needed to confirm our conclusion.

Funding Acknowledgement

Type of funding sources: None. Primary outcomeSecondary outcomes

Inhibitors of L-Type Calcium Channels Show Therapeutic Potential for Treating SARS-CoV-2 Infections by Preventing Virus Entry and Spread

COVID-19 is caused by a novel coronavirus, the severe acute respiratory syndrome coronavirus (CoV)-2 (SARS-CoV-2). The virus is responsible for an ongoing pandemic and concomitant public health crisis around the world. While vaccine development is proving to be highly successful, parallel drug development approaches are also critical in the response to SARS-CoV-2 and other emerging viruses. Coronaviruses require Ca2+ ions for host cell entry, and we have previously shown that Ca2+ modulates the interaction of the viral fusion peptide with host cell membranes. In an attempt to accelerate drug repurposing, we tested a panel of L-type calcium channel blocker (CCB) drugs currently developed for other conditions to determine whether they would inhibit SARS-CoV-2 infection in cell culture. All the CCBs tested showed varying degrees of inhibition, with felodipine and nifedipine strongly limiting SARS-CoV-2 entry and infection in epithelial lung cells at concentrations where cell toxicity was minimal. Further studies with pseudotyped particles displaying the SARS-CoV-2 spike protein suggested that inhibition occurs at the level of virus entry. Overall, our data suggest that certain CCBs have the potential to treat SARS-CoV-2 infections and are worthy of further examination for possible treatment of COVID-19.

Effects of miR-195 on diabetic nephropathy rats through targeting TLR4 and blocking NF-κB pathway

OBJECTIVE

The aim of this study was to explore the effects of micro ribonucleic acid (miR)-195 on diabetic nephropathy (DN) rats through targeting Toll-like receptor 4 (TLR4) and inhibiting the nuclear factor-κB (NF-κB) signaling pathway.

MATERIALS AND METHODS

The model of DN was first successfully established in rats. All rats were randomly divided into six groups, including control group (n=20), model group (n=20), 25 nM miR-195 mimics group (25 nM M group, n=20), 50 nM M group (n=20), 25 nM miR-195 inhibitor group (25 nM I group, n=20), and 50 nM I group (n=20). Urine volume, proteins and inflammatory factors were detected in each group, respectively. Subsequently, macrophages were cultured and transfected in vitro. The mRNA expressions of miR-195 and TLR4 in control group and model groups were determined using fluorescence quantitative polymerase chain reaction (qPCR). The protein expressions of TLR4 and NF-κB in macrophages were determined using Western blotting. Furthermore, the proliferation of macrophages was detected via cell counting kit-8 (CCK-8) assay.

RESULTS

Compared with model group, 24-h urine volume, urine protein, creatinine, urea nitrogen, tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and IL-6 levels declined significantly in 25 nM M group and 50 nM M group (p<0.05). However, they increased significantly in 25 nM I group and 50 nM I group (p<0.05). It could be suggested that miR-195 mimics might relieve the symptoms of DN rats. In kidney tissues in DN, miR-195 was lowly expressed, whereas TLR4 was highly expressed (p<0.01). This suggested that there was a negative correlation between the mRNA expressions of miR-195 and TLR4 (r2=0.4836, p=0.0007). After overexpression of miR-195, the protein expression of TLR4 was significantly reduced (p<0.01), indicating that miR-195 could negatively regulate the protein expression of TLR4. Besides, the protein expressions of TLR4 and NF-κB in si-TLR4 group were evidently lower than those in NC group (p<0.01). Meanwhile, they also had significant differences in si-TLR4 group compared with si-TLR4 + miR-195 inhibitor group (p<0.05). The above results demonstrated that the protein expressions of TLR4 and NF-κB in macrophages could be markedly inhibited by si-TLR4, but be promoted by si-TLR4 + miR-195 inhibitor. CCK-8 assay demonstrated that the proliferation ability of macrophages was remarkably weaker in miR-195 mimics group than NC group (p<0.001). Furthermore, it was also significantly weaker in si-TLR4 + miR-195 inhibitor group than si-TLR4 group (p<0.05).

CONCLUSIONS

MiR-195 reduces the release of inflammatory factors and inhibits the proliferation of macrophages through targeting TLR4 and blocking the NF-κB pathway, thereby alleviating the symptoms of DN rats.

Clinical and economic evaluation of a surveillance protocol to manage hepatitis B virus (HBV) reactivation among lymphoma patients with resolved HBV infection receiving rituximab

STUDY OBJECTIVE

To evaluate a surveillance protocol in managing the risk of hepatitis B virus (HBV) reactivation among lymphoma patients with resolved HBV infection receiving rituximab.

DESIGN

Prospective, single-arm study.

SETTING

National Cancer Centre, Singapore.

PATIENTS

Lymphoma patients with resolved HBV infection and scheduled to receive rituximab-based treatment.

INTERVENTION

Close monitoring of HBV DNA levels, ie. every 4-6 weeks during rituximab treatment, every 6-8 weeks in the first year post-treatment, and every 3-4 months in the second year post-treatment.

MEASUREMENTS

The efficacy of the surveillance protocol was examined by evaluating the rates of reactivation-related events. Feasibility was evaluated based on patient adherence. An economic analysis using a cost-minimization approach was conducted to compare the costs between the surveillance protocol and universal prophylaxis with entecavir 0.5 mg daily up to 1 year after cessation of rituximab.

MAIN RESULTS

A total of 66 patients provided analyzable data with a follow-up period of 966.6 months. No hepatitis flare or reactivation-related events were detected. The median adherence rate to the surveillance protocol was 90.5%. Cost savings of US$946.40 per patient over the entire surveillance period were achieved if the surveillance protocol was adopted and was most affected by changes in prophylaxis duration and the cost of antiviral prophylaxis.

CONCLUSIONS

The surveillance protocol is an effective, feasible and cost-saving strategy to manage HBV reactivation among lymphoma patients with resolved HBV infection receiving rituximab.

Nonequilibrium pattern formation in circularly confined two-dimensional systems with competing interactions

We numerically investigate the nonequilibrium behaviors of classic particles with competing interactions confined in a two-dimensional logarithmic trap. We reveal a quench-induced surprising dynamics exhibiting rich dynamic patterns depending upon confinement strength and trap size, which is attributed to the time-dependent competition between interparticle repulsions and attractions under a circular confinement. Moreover, in the collectively diffusive motions of the particles, we find that the emergence of dynamic structure transformation coincides with a diffusive mode transition from superdiffusion to subdiffusion. These findings are likely useful in understanding the pattern selection and evolution in various chemical and biological systems in addition to modulated systems, and add a new route to tailoring the morphology of pattern-forming systems.

Proteolytic Activation of SARS-CoV-2 Spike at the S1/S2 Boundary: Potential Role of Proteases beyond Furin

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) uses its spike (S) protein to mediate viral entry into host cells. Cleavage of the S protein at the S1/S2 and/or S2' site(s) is associated with viral entry, which can occur at either the cell plasma membrane (early pathway) or the endosomal membrane (late pathway), depending on the cell type. Previous studies show that SARS-CoV-2 has a unique insert at the S1/S2 site that can be cleaved by furin, which appears to expand viral tropism to cells with suitable protease and receptor expression. Here, we utilize viral pseudoparticles and protease inhibitors to study the impact of the S1/S2 cleavage on infectivity. Our results demonstrate that S1/S2 cleavage is essential for early pathway entry into Calu-3 cells, a model lung epithelial cell line, but not for late pathway entry into Vero E6 cells, a model cell line. The S1/S2 cleavage was found to be processed by other proteases beyond furin. Using bioinformatic tools, we also analyze the presence of a furin S1/S2 site in related CoVs and offer thoughts on the origin of the insertion of the furin-like cleavage site in SARS-CoV-2.

In Xenopus ependymal cilia drive embryonic CSF circulation and brain development independently of cardiac pulsatile forces

BACKGROUND

Hydrocephalus, the pathological expansion of the cerebrospinal fluid (CSF)-filled cerebral ventricles, is a common, deadly disease. In the adult, cardiac and respiratory forces are the main drivers of CSF flow within the brain ventricular system to remove waste and deliver nutrients. In contrast, the mechanics and functions of CSF circulation in the embryonic brain are poorly understood. This is primarily due to the lack of model systems and imaging technology to study these early time points. Here, we studied embryos of the vertebrate Xenopus with optical coherence tomography (OCT) imaging to investigate in vivo ventricular and neural development during the onset of CSF circulation.

METHODS

Optical coherence tomography (OCT), a cross-sectional imaging modality, was used to study developing Xenopus tadpole brains and to dynamically detect in vivo ventricular morphology and CSF circulation in real-time, at micrometer resolution. The effects of immobilizing cilia and cardiac ablation were investigated.

RESULTS

In Xenopus, using OCT imaging, we demonstrated that ventriculogenesis can be tracked throughout development until the beginning of metamorphosis. We found that during Xenopus embryogenesis, initially, CSF fills the primitive ventricular space and remains static, followed by the initiation of the cilia driven CSF circulation where ependymal cilia create a polarized CSF flow. No pulsatile flow was detected throughout these tailbud and early tadpole stages. As development progressed, despite the emergence of the choroid plexus in Xenopus, cardiac forces did not contribute to the CSF circulation, and ciliary flow remained the driver of the intercompartmental bidirectional flow as well as the near-wall flow. We finally showed that cilia driven flow is crucial for proper rostral development and regulated the spatial neural cell organization.

CONCLUSIONS

Our data support a paradigm in which Xenopus embryonic ventriculogenesis and rostral brain development are critically dependent on ependymal cilia-driven CSF flow currents that are generated independently of cardiac pulsatile forces. Our work suggests that the Xenopus ventricular system forms a complex cilia-driven CSF flow network which regulates neural cell organization. This work will redirect efforts to understand the molecular regulators of embryonic CSF flow by focusing attention on motile cilia rather than other forces relevant only to the adult.

Phase I study of selinexor in combination with dexamethasone, ifosfamide, carboplatin, etoposide chemotherapy in patients with relapsed or refractory peripheral T-cell or naturalkiller/T-cell lymphoma

Selinexor is a selective inhibitor of nuclear export with anti-cancer properties. We performed a phase I study to determine the safety and maximum tolerated dose of selinexor when combined with high-dose dexamethasone, ifosfamide, carboplatin and etoposide (DICE) in relapsed/refractory T-cell lymphoma (TCL) and natural-killer/T-cell lymphoma (NKTL). Patients with relapsed/refractory TCL and NKTL were treated with standard dose ICE, dexamethasone 20 mg on days 3 to 7, and escalating doses of oral selinexor on days 3, 5 and 7 in a 3+3 design. Dose levels (DL) 1, 2 and 3 were 40, 60 and 80 mg, respectively. Eleven patients with a median age of 60 years were enrolled; six at DL1 and five at DL2. Patients had received a median of two (range, 1-4) prior lines of treatment and seven had primary refractory disease at entry into the study. Patients received a median of three cycles (range, 1-6) of selinexor-DICE. The most common grade 1 or 2 toxicities included nausea (64%), fatigue (55%), and anorexia (45%) and the most common grade 3 or 4 toxicities included thrombocytopenia (82%), anemia (82%), neutropenia (73%), and hyponatremia (73%). Two patients developed dose-limiting toxicities at DL2 and one at DL1. Five patients discontinued treatment for reasons other than disease progression or lack of response. Of the ten evaluable patients, the overall and complete response rates were 91% and 82%, respectively. The maximum tolerated dose of selinexor was 40 mg when combined with DICE. The combination showed promising complete response rates in patients with relapsed/refractory TCL and NKTL but was poorly tolerated. (clinicaltrials. gov identifier: NCT03212937).

Abstract PO-35: Prognostic significance of MYC, BCL2, and BCL6 colocalization at single-cell resolution in DLBCL

MYC, BCL2, and BCL6 are commonly used markers for immunohistochemistry of Diffuse large B-cell lymphomas (DLBCL). Coexpression of MYC and BCL2 in particular constitutes a subgroup of “double expressor lymphomas” (DEL) with a distinct poor clinical outcome. However, it is not known if MYC and BCL2/BCL6 coexpression occurs in the same cell or in different cells within the tumor, as traditional immunohistochemistry (IHC) is limited by the number of markers that can be simultaneously assessed within formalin-fixed, paraffin-embedded (FFPE) samples. We set out to discover the clinical significance of MYC, BCL2, and BCL6 colocalization at single-cell resolution using multiplexed quantitative immunofluorescence (qIF) based on sequential OPAL-TSA staining and spectral microscopy on the Vectra platform. The initial discovery cohort comprised 90 cases of DLBCL from NUH Singapore with adequate clinical follow-up after R-CHOP therapy. We stratified each DLBCL tumor into 8 “clonal fractions” based on the possible permutations of MYC (M), BCL2 (2), and BCL6 (6) colocalization: M+2+6+, M+2+6-, M+2-6+, M+2-6-, M-2+6+, M-2-6+, M-2+6-, and M-2-6-. Interestingly, even within cases that fit traditional IHC criteria for “positivity” of MYC, BCL2, and BCL6, only a subset of cells within each case expressed multiple markers concurrently. Using the fraction of each of these clones as a continuous variable, Cox regression analysis revealed that the percentage of M+2+6- cells in a case was most predictive of poor survival. Importantly, the same clonal fraction (M+2+6-) was a significant poor prognostic feature in 2 smaller validation cohorts from SGH Singapore (n=41) and MD Anderson Cancer Centre USA (n=36). The single-cell staining pattern of these markers revealed a stark contrast between healthy tonsil tissue and DLBCL tissue. In the tonsil, colocalization of each marker was nonrandom (mutually exclusive BCL2 positivity in B cells outside the germinal center and BCL6 positivity inside the germinal center), whereas in DLBCL samples the mutual exclusivity pattern noted in the tonsil was lost, leading to a random distribution of colocalization of MYC, BCL2, and BCL6. The random nature of this colocalization allowed us to mathematically predict the “extent” of these 8 subclones from any data set with quantitative data of each single marker (MYC, BCL2, and BCL6). We therefore attempted to evaluate this model in RNA expression datasets of DLBCL cases with clinically annotated data. Remarkably, in concordance with our IF data, the “predicted” M+2+ 6- subgroup consistently was associated with an unfavorable prognosis in 3 independent mRNA datasets (GSE10846 n=233, GSE117556 n=469, GSE32918 n=140). In summary, we have for the first time assessed the expression of MYC, BCL2, and BCL6 at the single-cell level in DLBCL. These results may explain the apparent protective function of BCL6 expression in prior cohort studies of DEL, and provide a quantitative tool for the identification of DLBCL cases with poor survival on R-CHOP.

Citation Format: Michal Hoppe, Shuangyi Fan, Patrick Jaynes, Phuong Mai Hoang, Liu Xin, Sanjay De Mel, Li Mei Poon, Esther Chan, Joanne Lee, Yen Lin Chee, Choon Kiat Ong, Tiffany Tang, Soon Thye Lim, Nicholas Francis Grigoropoulos, Sheng-Tsung Chang, Shih-Sung Chuang, Joseph Khoury, Hyungwon Choi, Wee Joo Chng, Siok-Bian Ng, Claudio Tripodo, Anand D. Jeyasekharan. Prognostic significance of MYC, BCL2, and BCL6 colocalization at single-cell resolution in DLBCL [abstract]. In: Proceedings of the AACR Virtual Meeting: Advances in Malignant Lymphoma; 2020 Aug 17-19. Philadelphia (PA): AACR; Blood Cancer Discov 2020;1(3_Suppl):Abstract nr PO-35.

Clinical Features of Plasmablastic Lymphoma: Case Series From an Asian Tertiary Cancer Center and Literature Review

Background

Plasmablastic lymphoma (PBL) is an aggressive subtype of mature B-cell non-Hodgkin lymphoma. Given its rarity, there remains a lack of clinicopathological data to guide its management, particularly on Asian patients.

Methods

We conducted a retrospective chart review of 10 patients diagnosed with PBL at the National Cancer Centre Singapore and performed a literature review of similar studies on Asian cohorts.

Results

Most patients were male (n = 9), with median age at diagnosis of 55 years (range, 33 - 91 years). Seven (70%) patients were considered to be immunocompromised. In the overall cohort, the median overall survival (OS) was 19.4 months with 5-year survival estimates given at 60% and 36% for OS and progression-free survival (PFS), respectively. At diagnosis, patients with HIV/AIDS (n = 5) were younger compared to others (median, 43 vs. 61 years; P = 0.0278), had greater number of nodal site involvement (median, 6 vs. 0; P = 0.0333), and higher international prognostic index (IPI) scores (P = 0.034 for trend). Amongst different chemotherapy used, etoposide, prednisone, vincristine, cyclophosphamide and doxorubicin (EPOCH)-based regimens (n = 6) elicited prominent complete response rates (83%) and led to durable responses even in the setting of advanced stage, high-risk IPI score and immunodeficiency.

Conclusions

In conclusion, our study describes the features of PBL in an Asian cohort and highlights disease features unique to HIV-associated PBL.

Suppressions of vibration in the Tip-Tilt mirror control system by add-on controller

Tip-Tilt mirrors play an important role in astronomical telescopes requiring the tracking performance at the level of microradian or sub-microradian. However, the closed-loop performance suffers a lot from the low-sample rate and time delay of image sensors. Especially, this issue is under the condition of vibrations, because dynamic behaviors are complex and the models are difficult to be obtained accurately. Another challenging issue comes from the measurement of vibrations and its extraction for the closed-loop control. This paper proposes a new method based on an add-on controller of the Tip-Tilt mirror to mitigate telescope vibrations. The proposed method only uses Tip-Tilt errors from an image sensor to implement a disturbance observer, which is not being restricted by an accurate model. As a result, the closed-loop performance can be optimized by designing of a proper Q-filter. To suppress the low-frequency and high-frequency vibrations, a novel Q-filter combining a lowpass filter and a bandpass filter is proposed here. The improved control method is validated by both simulation and experiment in the tip-tilt mirror control system under the condition of vibrations.