SLAM-ITseq identifies that Nrf2 induces liver regeneration through the pentose phosphate pathway

The liver exhibits a remarkable capacity to regenerate following injury. Despite this unique attribute, toxic injury is a leading cause of liver failure. The temporal processes by which the liver senses injury and initiates regeneration remain unclear. Here, we developed a transgenic zebrafish model wherein hepatocyte-specific expression of uracil phosphoribosyltransferase (UPRT) enabled the implementation of SLAM-ITseq to investigate the nascent transcriptome during initiation of liver injury and regeneration. Using this approach, we identified a rapid metabolic transition from the fed to the fasted state that was followed by induction of the nuclear erythroid 2-related factor (Nrf2) antioxidant program. We find that activation of Nrf2 in hepatocytes is required to induce the pentose phosphate pathway (PPP) and improve survival following liver injury. Mechanistically, we demonstrate that inhibition of the PPP disrupts nucleotide biosynthesis to prevent liver regeneration. Together, these studies provide fundamental insights into the mechanism by which early metabolic adaptation to injury facilitates tissue regeneration.

Effects of empagliflozin on progression of chronic kidney disease: a prespecified secondary analysis from the empa-kidney trial

BACKGROUND

Sodium-glucose co-transporter-2 (SGLT2) inhibitors reduce progression of chronic kidney disease and the risk of cardiovascular morbidity and mortality in a wide range of patients. However, their effects on kidney disease progression in some patients with chronic kidney disease are unclear because few clinical kidney outcomes occurred among such patients in the completed trials. In particular, some guidelines stratify their level of recommendation about who should be treated with SGLT2 inhibitors based on diabetes status and albuminuria. We aimed to assess the effects of empagliflozin on progression of chronic kidney disease both overall and among specific types of participants in the EMPA-KIDNEY trial.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA), and included individuals aged 18 years or older with an estimated glomerular filtration rate (eGFR) of 20 to less than 45 mL/min per 1·73 m2, or with an eGFR of 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher. We explored the effects of 10 mg oral empagliflozin once daily versus placebo on the annualised rate of change in estimated glomerular filtration rate (eGFR slope), a tertiary outcome. We studied the acute slope (from randomisation to 2 months) and chronic slope (from 2 months onwards) separately, using shared parameter models to estimate the latter. Analyses were done in all randomly assigned participants by intention to treat. EMPA-KIDNEY is registered at ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and then followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroups of eGFR included 2282 (34·5%) participants with an eGFR of less than 30 mL/min per 1·73 m2, 2928 (44·3%) with an eGFR of 30 to less than 45 mL/min per 1·73 m2, and 1399 (21·2%) with an eGFR 45 mL/min per 1·73 m2 or higher. Prespecified subgroups of uACR included 1328 (20·1%) with a uACR of less than 30 mg/g, 1864 (28·2%) with a uACR of 30 to 300 mg/g, and 3417 (51·7%) with a uACR of more than 300 mg/g. Overall, allocation to empagliflozin caused an acute 2·12 mL/min per 1·73 m2 (95% CI 1·83-2·41) reduction in eGFR, equivalent to a 6% (5-6) dip in the first 2 months. After this, it halved the chronic slope from -2·75 to -1·37 mL/min per 1·73 m2 per year (relative difference 50%, 95% CI 42-58). The absolute and relative benefits of empagliflozin on the magnitude of the chronic slope varied significantly depending on diabetes status and baseline levels of eGFR and uACR. In particular, the absolute difference in chronic slopes was lower in patients with lower baseline uACR, but because this group progressed more slowly than those with higher uACR, this translated to a larger relative difference in chronic slopes in this group (86% [36-136] reduction in the chronic slope among those with baseline uACR <30 mg/g compared with a 29% [19-38] reduction for those with baseline uACR ≥2000 mg/g; ptrend<0·0001).

INTERPRETATION

Empagliflozin slowed the rate of progression of chronic kidney disease among all types of participant in the EMPA-KIDNEY trial, including those with little albuminuria. Albuminuria alone should not be used to determine whether to treat with an SGLT2 inhibitor.

FUNDING

Boehringer Ingelheim and Eli Lilly.

Impact of primary kidney disease on the effects of empagliflozin in patients with chronic kidney disease: secondary analyses of the EMPA-KIDNEY trial

BACKGROUND

The EMPA-KIDNEY trial showed that empagliflozin reduced the risk of the primary composite outcome of kidney disease progression or cardiovascular death in patients with chronic kidney disease mainly through slowing progression. We aimed to assess how effects of empagliflozin might differ by primary kidney disease across its broad population.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA). Patients were eligible if their estimated glomerular filtration rate (eGFR) was 20 to less than 45 mL/min per 1·73 m2, or 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher at screening. They were randomly assigned (1:1) to 10 mg oral empagliflozin once daily or matching placebo. Effects on kidney disease progression (defined as a sustained ≥40% eGFR decline from randomisation, end-stage kidney disease, a sustained eGFR below 10 mL/min per 1·73 m2, or death from kidney failure) were assessed using prespecified Cox models, and eGFR slope analyses used shared parameter models. Subgroup comparisons were performed by including relevant interaction terms in models. EMPA-KIDNEY is registered with ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroupings by primary kidney disease included 2057 (31·1%) participants with diabetic kidney disease, 1669 (25·3%) with glomerular disease, 1445 (21·9%) with hypertensive or renovascular disease, and 1438 (21·8%) with other or unknown causes. Kidney disease progression occurred in 384 (11·6%) of 3304 patients in the empagliflozin group and 504 (15·2%) of 3305 patients in the placebo group (hazard ratio 0·71 [95% CI 0·62-0·81]), with no evidence that the relative effect size varied significantly by primary kidney disease (pheterogeneity=0·62). The between-group difference in chronic eGFR slopes (ie, from 2 months to final follow-up) was 1·37 mL/min per 1·73 m2 per year (95% CI 1·16-1·59), representing a 50% (42-58) reduction in the rate of chronic eGFR decline. This relative effect of empagliflozin on chronic eGFR slope was similar in analyses by different primary kidney diseases, including in explorations by type of glomerular disease and diabetes (p values for heterogeneity all >0·1).

INTERPRETATION

In a broad range of patients with chronic kidney disease at risk of progression, including a wide range of non-diabetic causes of chronic kidney disease, empagliflozin reduced risk of kidney disease progression. Relative effect sizes were broadly similar irrespective of the cause of primary kidney disease, suggesting that SGLT2 inhibitors should be part of a standard of care to minimise risk of kidney failure in chronic kidney disease.

FUNDING

Boehringer Ingelheim, Eli Lilly, and UK Medical Research Council.

Inhibition of METTL3 Results in a Cell-Intrinsic Interferon Response That Enhances Antitumor Immunity

Therapies that enhance antitumor immunity have altered the natural history of many cancers. Consequently, leveraging nonoverlapping mechanisms to increase immunogenicity of cancer cells remains a priority. Using a novel enzymatic inhibitor of the RNA methyl-transferase METTL3, we demonstrate a global decrease in N6-methyladenosine (m6A) results in double-stranded RNA (dsRNA) formation and a profound cell-intrinsic interferon response. Through unbiased CRISPR screens, we establish dsRNA-sensing and interferon signaling are primary mediators that potentiate T-cell killing of cancer cells following METTL3 inhibition. We show in a range of immunocompetent mouse models that although METTL3 inhibition is equally efficacious to anti-PD-1 therapy, the combination has far greater preclinical activity. Using SPLINTR barcoding, we demonstrate that anti-PD-1 therapy and METTL3 inhibition target distinct malignant clones, and the combination of these therapies overcomes clones insensitive to the single agents. These data provide the mole-cular and preclinical rationale for employing METTL3 inhibitors to promote antitumor immunity in the clinic.

SIGNIFICANCE

This work demonstrates that METTL3 inhibition stimulates a cell-intrinsic interferon response through dsRNA formation. This immunomodulatory mechanism is distinct from current immunotherapeutic agents and provides the molecular rationale for combination with anti-PD-1 immune-checkpoint blockade to augment antitumor immunity. This article is featured in Selected Articles from This Issue, p. 2109.

CRISPR-ChIP reveals selective regulation of H3K79me2 by Menin in MLL leukemia

Chromatin regulation involves the selective recruitment of chromatin factors to facilitate DNA repair, replication and transcription. Here we demonstrate the utility of coupling unbiased functional genomics with chromatin immunoprecipitation (CRISPR-ChIP) to identify the factors associated with active chromatin modifications in mammalian cells. Specifically, an integrated reporter containing a cis-regulatory element of interest and a single guide RNA provide a chromatinized template for a direct readout for regulators of histone modifications associated with actively transcribed genes such as H3K4me3 and H3K79me2. With CRISPR-ChIP, we identify all the nonredundant COMPASS complex members required for H3K4me3 and demonstrate that RNA polymerase II is dispensable for the maintenance of H3K4me3. As H3K79me2 has a putative oncogenic function in leukemia cells driven by MLL translocations, using CRISPR-ChIP we reveal a functional partitioning of H3K79 methylation into two distinct regulatory units: an oncogenic DOT1L complex directed by the MLL fusion protein in a Menin-dependent manner and a separate endogenous DOT1L complex, where catalytic activity is directed by MLLT10. Overall, CRISPR-ChIP provides a powerful tool for the unbiased interrogation of the mechanisms underpinning chromatin regulation.

Targeting Menin disrupts the KMT2A/B and polycomb balance to paradoxically activate bivalent genes

Precise control of activating H3K4me3 and repressive H3K27me3 histone modifications at bivalent promoters is essential for normal development and frequently corrupted in cancer. By coupling a cell surface readout of bivalent MHC class I gene expression with whole-genome CRISPR-Cas9 screens, we identify specific roles for MTF2-PRC2.1, PCGF1-PRC1.1 and Menin-KMT2A/B complexes in maintaining bivalency. Genetic loss or pharmacological inhibition of Menin unexpectedly phenocopies the effects of polycomb disruption, resulting in derepression of bivalent genes in both cancer cells and pluripotent stem cells. While Menin and KMT2A/B contribute to H3K4me3 at active genes, a separate Menin-independent function of KMT2A/B maintains H3K4me3 and opposes polycomb-mediated repression at bivalent genes. Release of KMT2A from active genes following Menin targeting alters the balance of polycomb and KMT2A at bivalent genes, facilitating gene activation. This functional partitioning of Menin-KMT2A/B complex components reveals therapeutic opportunities that can be leveraged through inhibition of Menin.

Inhibition of the CtBP complex and FBXO11 enhances MHC class II expression and anti-cancer immune responses

There is increasing recognition of the prognostic significance of tumor cell major histocompatibility complex (MHC) class II expression in anti-cancer immunity. Relapse of acute myeloid leukemia (AML) following allogeneic stem cell transplantation (alloSCT) has recently been linked to MHC class II silencing in leukemic blasts; however, the regulation of MHC class II expression remains incompletely understood. Utilizing unbiased CRISPR-Cas9 screens, we identify that the C-terminal binding protein (CtBP) complex transcriptionally represses MHC class II pathway genes, while the E3 ubiquitin ligase complex component FBXO11 mediates degradation of CIITA, the principal transcription factor regulating MHC class II expression. Targeting these repressive mechanisms selectively induces MHC class II upregulation across a range of AML cell lines. Functionally, MHC class II+ leukemic blasts stimulate antigen-dependent CD4+ T cell activation and potent anti-tumor immune responses, providing fundamental insights into the graft-versus-leukemia effect. These findings establish the rationale for therapeutic strategies aimed at restoring tumor-specific MHC class II expression to salvage AML relapse post-alloSCT and also potentially to enhance immunotherapy outcomes in non-myeloid malignancies.

Pharmacologic Reduction of Mitochondrial Iron Triggers a Noncanonical BAX/BAK-Dependent Cell Death

Cancer cell metabolism is increasingly recognized as providing an exciting therapeutic opportunity. However, a drug that directly couples targeting of a metabolic dependency with the induction of cell death in cancer cells has largely remained elusive. Here we report that the drug-like small-molecule ironomycin reduces the mitochondrial iron load, resulting in the potent disruption of mitochondrial metabolism. Ironomycin promotes the recruitment and activation of BAX/BAK, but the resulting mitochondrial outer membrane permeabilization (MOMP) does not lead to potent activation of the apoptotic caspases, nor is the ensuing cell death prevented by inhibiting the previously established pathways of programmed cell death. Consistent with the fact that ironomycin and BH3 mimetics induce MOMP through independent nonredundant pathways, we find that ironomycin exhibits marked in vitro and in vivo synergy with venetoclax and overcomes venetoclax resistance in primary patient samples.

SIGNIFICANCE

Ironomycin couples targeting of cellular metabolism with cell death by reducing mitochondrial iron, resulting in the alteration of mitochondrial metabolism and the activation of BAX/BAK. Ironomycin induces MOMP through a different mechanism to BH3 mimetics, and consequently combination therapy has marked synergy in cancers such as acute myeloid leukemia. This article is highlighted in the In This Issue feature, p. 587.

Non-genetic determinants of malignant clonal fitness at single-cell resolution

All cancers emerge after a period of clonal selection and subsequent clonal expansion. Although the evolutionary principles imparted by genetic intratumour heterogeneity are becoming increasingly clear¹, little is known about the non-genetic mechanisms that contribute to intratumour heterogeneity and malignant clonal fitness². Here, using single-cell profiling and lineage tracing (SPLINTR)-an expressed barcoding strategy-we trace isogenic clones in three clinically relevant mouse models of acute myeloid leukaemia. We find that malignant clonal dominance is a cell-intrinsic and heritable property that is facilitated by the repression of antigen presentation and increased expression of the secretory leukocyte peptidase inhibitor gene (Slpi), which we genetically validate as a regulator of acute myeloid leukaemia. Increased transcriptional heterogeneity is a feature that enables clonal fitness in diverse tissues and immune microenvironments and in the context of clonal competition between genetically distinct clones. Similar to haematopoietic stem cells³, leukaemia stem cells (LSCs) display heritable clone-intrinsic properties of high, and low clonal output that contribute to the overall tumour mass. We demonstrate that LSC clonal output dictates sensitivity to chemotherapy and, although high- and low-output clones adapt differently to therapeutic pressure, they coordinately emerge from minimal residual disease with increased expression of the LSC program. Together, these data provide fundamental insights into the non-genetic transcriptional processes that underpin malignant clonal fitness and may inform future therapeutic strategies.

Three-dimensional CRISPR screening reveals epigenetic interaction with anti-angiogenic therapy

Angiogenesis underlies development, physiology and pathogenesis of cancer, eye and cardiovascular diseases. Inhibiting aberrant angiogenesis using anti-angiogenic therapy (AAT) has been successful in the clinical treatment of cancer and eye diseases. However, resistance to AAT inevitably occurs and its molecular basis remains poorly understood. Here, we uncover molecular modifiers of the blood endothelial cell (EC) response to a widely used AAT bevacizumab by performing a pooled genetic screen using three-dimensional microcarrier-based cell culture and CRISPR–Cas9. Functional inhibition of the epigenetic reader BET family of proteins BRD2/3/4 shows unexpected mitigating effects on EC survival and/or proliferation upon VEGFA blockade. Moreover, transcriptomic and pathway analyses reveal an interaction between epigenetic regulation and anti-angiogenesis, which may affect chromosomal structure and activity in ECs via the cell cycle regulator CDC25B phosphatase. Collectively, our findings provide insight into epigenetic regulation of the EC response to VEGFA blockade and may facilitate development of quality biomarkers and strategies for overcoming resistance to AAT.

Through three-dimensional CRISPR screening, He et al. report that functional inhibition of BET family of proteins BRD2/3/4 shows mitigating effects on blood endothelial cell (EC) survival and/or proliferation upon VEGFA blockade. An interaction between epigenetic regulation and anti-angiogenesis, which may affect chromosomal structure and activity in ECs through CDC25B phosphatase, is potentially involved with EC resistance to anti-angiogenic therapy.

Lo, the ever confounding nipple shadow!

The discovery of a solitary pulmonary nodule (SPN) on chest imaging can be alarming for both the clinician and the patient. In the absence of a uniform guideline, managing SPN is nothing short of challenging for primary care physicians (PCPs). We present a case here of a patient presenting with prolonged cough who also displayed unilateral SPN on her chest radiograph. Through further examination, this presence was later shown to be a nipple shadow simulating SPN, and the patient was spared unnecessary testing and psychological distress.

Methods and clinical outcomes of in situ fenestration for aortic arch revascularization during thoracic endovascular aortic repair

OBJECTIVE

Despite endovascular advances in fenestrated and branched devices, thoracic endovascular aortic repair (TEVAR) for arch pathologies remains challenging. The aim of this study was to provide a contemporary review on the current evidence for in situ fenestration during TEVAR and to evaluate its short- and mid-term clinical outcome in the management of arch pathology.

METHODS

A systematic literature review on in situ fenestration of thoracic aortic stent-graft from January 2003 to September 2018 was performed under the instruction of Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Statement.

RESULTS

Our initial search yielded 169 studies, of which 21 articles were relevant to the topic and were finally included. One hundred and forty-five in situ fenestration procedures in 99 patients were reviewed, involving 25 innominate arteries (17%), 33 left common carotid arteries (23%) and 87 left subclavian arteries (60%). Twelve patients (12/99, 12%) had two-vessel fenestration and three-vessel fenestration was performed in 17 patients (17/99, 17%). Technical success was achieved in 136 arteries (136/145, 93%). Talent/Valiant with monofilament twill woven polyester fabric was the most common (50/99, 51%) stent-graft used for fenestration. Three methods reported for in situ fenestration were needle, laser and radiofrequency. Needle was the most frequently used device for fenestration, which was performed in 60 patients (60/99, 61%). Three patients (3/99, 3%) died with 30 days, none were in situ fenestration TEVAR procedure-related. Perioperative complications including one (1%) retrograde type A aortic dissection, two (2%) type II endoleaks, and three (3%) strokes were reported. The pooled estimate for overall technical success, perioperative mortality and stroke was 88.3% (95% CI, 78.6%-93.9%), 5.9% (95% CI, 2.5%-13.4%) and 9.5% (95% CI, 4.1%-20.6%), respectively. Four patients (4/96, 4%) died during follow-up, none were aortic-related. All the fenestration bridging stents were reportedly patent, with only 1 (1/96, 1%) asymptomatic left subclavian stent stenosis. Two patients (2/96, 2%) with type II endoleak from left subclavian artery required secondary intervention.

CONCLUSION

In situ fenestration appeared to be a feasible and effective method to extend proximal landing zone during TEVAR. It had an acceptable short-term result with high technical success and low fenestration related morbidity. Long-term durability data were lacking, and there was no high level evidence to recommend the routine use of in situ fenestration TEVAR for the management of arch pathology.

HBO1 is required for the maintenance of leukaemia stem cells

Acute myeloid leukaemia (AML) is a heterogeneous disease characterized by transcriptional dysregulation that results in a block in differentiation and increased malignant self-renewal. Various epigenetic therapies aimed at reversing these hallmarks of AML have progressed into clinical trials, but most show only modest efficacy owing to an inability to effectively eradicate leukaemia stem cells (LSCs)1. Here, to specifically identify novel dependencies in LSCs, we screened a bespoke library of small hairpin RNAs that target chromatin regulators in a unique ex vivo mouse model of LSCs. We identify the MYST acetyltransferase HBO1 (also known as KAT7 or MYST2) and several known members of the HBO1 protein complex as critical regulators of LSC maintenance. Using CRISPR domain screening and quantitative mass spectrometry, we identified the histone acetyltransferase domain of HBO1 as being essential in the acetylation of histone H3 at K14. H3 acetylated at K14 (H3K14ac) facilitates the processivity of RNA polymerase II to maintain the high expression of key genes (including Hoxa9 and Hoxa10) that help to sustain the functional properties of LSCs. To leverage this dependency therapeutically, we developed a highly potent small-molecule inhibitor of HBO1 and demonstrate its mode of activity as a competitive analogue of acetyl-CoA. Inhibition of HBO1 phenocopied our genetic data and showed efficacy in a broad range of human cell lines and primary AML cells from patients. These biological, structural and chemical insights into a therapeutic target in AML will enable the clinical translation of these findings.

An Evolutionarily Conserved Function of Polycomb Silences the MHC Class I Antigen Presentation Pathway and Enables Immune Evasion in Cancer

Loss of MHC class I (MHC-I) antigen presentation in cancer cells can elicit immunotherapy resistance. A genome-wide CRISPR/Cas9 screen identified an evolutionarily conserved function of polycomb repressive complex 2 (PRC2) that mediates coordinated transcriptional silencing of the MHC-I antigen processing pathway (MHC-I APP), promoting evasion of T cell-mediated immunity. MHC-I APP gene promoters in MHC-I low cancers harbor bivalent activating H3K4me3 and repressive H3K27me3 histone modifications, silencing basal MHC-I expression and restricting cytokine-induced upregulation. Bivalent chromatin at MHC-I APP genes is a normal developmental process active in embryonic stem cells and maintained during neural progenitor differentiation. This physiological MHC-I silencing highlights a conserved mechanism by which cancers arising from these primitive tissues exploit PRC2 activity to enable immune evasion.

Targeting enhancer switching overcomes non-genetic drug resistance in acute myeloid leukaemia

Non-genetic drug resistance is increasingly recognised in various cancers. Molecular insights into this process are lacking and it is unknown whether stable non-genetic resistance can be overcome. Using single cell RNA-sequencing of paired drug naïve and resistant AML patient samples and cellular barcoding in a unique mouse model of non-genetic resistance, here we demonstrate that transcriptional plasticity drives stable epigenetic resistance. With a CRISPR-Cas9 screen we identify regulators of enhancer function as important modulators of the resistant cell state. We show that inhibition of Lsd1 (Kdm1a) is able to overcome stable epigenetic resistance by facilitating the binding of the pioneer factor, Pu.1 and cofactor, Irf8, to nucleate new enhancers that regulate the expression of key survival genes. This enhancer switching results in the re-distribution of transcriptional co-activators, including Brd4, and provides the opportunity to disable their activity and overcome epigenetic resistance. Together these findings highlight key principles to help counteract non-genetic drug resistance.

Clinical Toxicology and Overdose of Psychiatric Medications

This article reviews the poisoning epidemiology in Hong Kong, assessment and treatment of acute poisoning, and management of acute psychiatric medication overdose. In 2016, nearly 4000 poisoning cases involving approximately 6000 poisons were reported to Hong Kong Poison Information Centre. About 25% of the poisons involved were psychiatric-related medications. The initial medical assessment on poisoning includes history taking, vital signs monitoring, and focused physical examination. Approaches in managing acute poisoning include supportive measures, decontamination, antidote use, and enhanced elimination. Management on overdose of psychiatric medications (zopiclone, tricyclic antidepressants, selective serotonin reuptake inhibitor, antipsychotics, valproic acid, lithium, and methylphenidate) are discussed with practical tips highlighted.

Delayed open conversion after endovascular aortic repair

AIM

We present the clinical outcomes of patients who underwent delayed (>30 days) open surgical repair after endovascular aortic aneurysm repair.

METHODS

All patients receiving delayed open repair of infrarenal and juxtarenal aortic aneurysms after endovascular repair from July 2001 to December 2017 were retrospectively reviewed. Patients' baseline characteristics, indications for delayed open conversion, and time between endovascular repair and open conversion are described. Early outcomes included operative approach, morbidity, and mortality. Midterm outcomes included survival.

RESULTS

Twenty-two (3.3%) of 667 patients with prior infrarenal endovascular aortic aneurysm repair had delayed open conversion (20 elective and 2 emergency). The time from endovascular repair to open conversion was 60 ± 36 months. The indications were 6 (27%) type Ia endoleaks, 6 (27%) type II endoleaks with enlarging sac size, 2 (9%) endotensions, 7 (32%) unknown types of endoleak, and 1 (5%) graft infection. The 7 minutes unknown endoleaks were confirmed as lumbar leaks in 4 cases and fabric leaks in 3. Operative time was 222 ± 48 min with blood loss of 2211 ± 2057 mL. Hospital stay after conversion was 12 ± 8 days. There was no 30-day mortality. Estimated survival rates were 96%, 91%, 86%, 79% and 57% at 1, 2, 3, 4, and 5 years postoperatively.

CONCLUSION

Delayed conversion to open surgery after endovascular aortic aneurysm repair by endograft explantation appears to be safe with good short- and mid-term outcomes. With careful preoperative assessment, open conversion remained a realistic and viable option in patients with failed endovascular treatment.

Arch branch endografts for arch aneurysms associated with bovine anomaly

Bovine aortic arch is known to be associated with an increased rate of aortic arch expansion. The most frequently observed human variant of bovine aortic arch is a common origin of the innominate trunk and left common carotid artery. This is a report of two patients who had successful custom-made arch branch endograft treatment for an arch aneurysm associated with bovine arch anomaly. Modular endovascular repair of aortic arch aneurysms using an inner-branched device adds to the armamentarium of treatment options, and is a minimally invasive management modality without the need for sternotomy or intraoperative extracorporeal bypass.

Accidental Ecstasy Poisoning in a Five-Year-Old Boy

We report a 5-year-old child with fever and confusion after ingestion of a tablet of methylenedioxymethamphetamine (MDMA). He was treated successfully with supportive measures and titrated doses of benzodiazepine. In children with unexplained fever, sympathetic hyperactivity, confusion or convulsion, MDMA poisoning should be considered.

Hong Kong Poison Information Centre: Annual Report 2015

Objective

To report and analyse the poisoning data of Hong Kong Poison Information Centre (HKPIC) in 2015.

Methods

In 2015, all poisoning cases received by HKPIC were retrieved from its database [Poison Information and Clinical Management System (PICMS)] for analysis.

Results

A total of 3,960 poisoned cases were analysed. There were 1,770 male patients (44.7%), 2,176 female patients (55.0%) and 14 sex unspecified patients (0.4%). The majority of the cases (63.5%) were between 20 and 59 years old. Common causes for poisoning were suspected self-harm/suicidal attempt (38.4%), unintentional exposure (17.4%) and abusive substances use (11.6%). Excluding the common co-ingestant ethanol, the five commonest types of poison were paracetamol, benzodiazepine, household products, zopiclone and Chinese herbal medicine. Most patients were managed with supportive measures, while 16.4% and 16.2% of them were treated by decontamination and antidotes respectively. Majority of the cases had uneventful recovery; 1% resulted in death and 4.3% had major outcomes. Seven interesting cases and one outbreak were discussed.

Conclusions

This 10th annual report provided updated epidemiological information on poisoning pattern in Hong Kong and highlighted important changes in comparing with our previous reports.

Hong Kong Poison Information Centre: Annual Report 2008

Objective

To report the poisoning data of Hong Kong Poison Information Centre (HKPIC) in 2008.

Methods

From 1st January 2008 to 31st December 2008, all poisoning cases received by HKPIC were retrieved from its database (DATOX & PIC-MS) for analysis.

Results

4,029 poisoned cases were analyzed. There were 1,755 male patients (43.6%) and 2,262 female patients (56.1%). Nearly two-thirds of them were between 20 and 59 years old. Common causes of exposure were suspected self harm/suicidal attempt, unintentional exposure and abusive use. Sedatives, household products, paracetamol, and ketamine were common poisons exposed and non-benzodiazepine sedative-hypnotics were involved in about one-seventh of the poisoning cases. The majority of the patients were managed conservatively, with 6.0% and 5.9% treated by decontamination and antidotes respectively. Most cases had uneventful recovery; about 1% of the poison exposure resulted in death and about 5% of the exposure had major outcomes.

Conclusions

This annual report provides updated epidemiological information on poisoning in Hong Kong in 2008 and highlights some changes in comparison with our previous reports. The increase in abusive substance poisoning, in particular ketamine, requires further attention.

Venomous Fish Sting Cases Reported to Hong Kong Poison Information Centre: A Three-Year Retrospective Study on Epidemiology and Management

Objective

To study the epidemiology of venomous fish sting injuries, management and clinical outcomes of injured patients reported to the Hong Kong Poison Information Centre (HKPIC).

Methods

All venomous fish sting cases reported to HKPIC from July 2005 to June 2008 were retrieved from its database (DATOX) and the Hong Kong Hospital Authority (HA) Electronic Patient Record (ePR) computer system for analysis.

Results

There were a total of 33 fish sting cases in this study. The average age of the patients was 43 years (range 20 to 84) and 24 patients were males. Most cases were injured by catfish (n=12), followed by stonefish (n=7) and lionfish (n=4). Ten cases sustained fish sting injury whilst at work. Five patients developed fish sting complications including cellulitis, subacute tenosynovitis, abscess formation and foreign body retention. No mortality was recorded. Within 7 cases of stonefish injury, 3 cases were classified as moderate effect outcome. Two patients received stonefish antivenom and none developed anaphylaxis.

Conclusion

The majority of marine envenomations did not result in significant morbidity and required only supportive management. However, stonefish injuries might be associated with an increased risk of severe local symptoms which therefore required aggressive treatment including antivenom.

Hong Kong Poison Information Centre: Annual Report 2007

Objective

To report the poisoning data of Hong Kong Poison Information Centre (HKPIC) in 2007.

Methods

From 1st January 2007 to 31st December 2007, all poisoning cases received by HKPIC were retrieved from its database (DATOX) for analysis.

Results

2842 poisoned cases were analyzed. There were 1199 male and 1610 female patients and more than two-thirds of the cases were between 20 and 59 years old. Common causes of exposure were suicidal attempt, accident and abusive use. Non-benzodiazepine sedative-hypnotic, household products and paracetamol were common poisons exposed. The majority of the patients were managed conservatively, with 8.4% and 6.4% treated by decontamination and antidotes respectively. Most cases had uneventful recovery; less than 1% of the poison exposure resulted in death and about 5% of the exposure had major outcomes.

Conclusions

This 2007 annual report provided updated epidemiological information on the poisoning pattern in Hong Kong and highlighted some changes in comparison to the situation in 2006.

Extensive Bowel Ischaemia after Nifedipine Overdose

A 57-year-old woman presented with abdominal distension and vomiting two days after overdosing an unknown amount of sustained-release nifedipine tablets. She had refractory shock requiring calcium chloride, glucagon, insulin-glucose and multiple high-dose inotropic agent infusions in the intensive care unit. Her abdominal computed tomography showed features of bowel ischaemia and exploratory laporotomy reviewed non-salvageable massive bowel ischaemia. She finally succumbed after 22 days of hospital treatment. This case illustrates the importance of awareness of this potentially fatal complication of calcium channel blocker overdose, requiring early recognition and intervention.

Reliability and Validity of the “Extended - Hurt, Insult, Threaten, Scream” (E-Hits) Screening Tool in Detecting Intimate Partner Violence in Hospital Emergency Departments in Hong Kong

Objectives

To assess the reliability and validity of a brief screening instrument, “E-HITS” (Extended - Hurt, Insult, Threaten, Scream), for detecting female intimate partner violence (IPV) in Hong Kong emergency departments (EDs).

Method

Quantitative data were collected from a victim group (n=110) and a control group (n=116). Statistical properties of the instruments were analysed to ascertain its internal consistency, test/re-test reliability, concurrent validity and discriminant validity.

Results

Cronbach's alpha was 0.90 for the E-HITS. Two-week test/re-test reliability was 0.71 (p<0.001). Respondents' scores on the E-HITS positively correlated with those on psychological aggression, physical assault, sexual coercion and injury scales, and negatively correlated with the negotiation scale of the revised Conflict Tactics Scale at a statistically significant level. Subsequent Receiver Operating Characteristic (ROC) curve analysis revealed that E-HITS reached a sensitivity of 98.2% and a specificity of 94.8% at a cut-off of 8.5. The overall accuracy of the E-HITS indicated by the area under curve (AUC) in the ROC is 0.991.

Conclusion

These results show that the E-HITS has good internal consistency, test/re-test reliability, as well as concurrent and discriminant validity. The E-HITS is a valid and reliable tool for screening intimate partner violence in Hong Kong EDs.

Hong Kong Poison Information Centre: Annual Report 2009

Objective

To report and analyse the poisoning data of Hong Kong Poison Information Centre (HKPIC) in 2009.

Methods

In 2009, all poisoning cases received by HKPIC were retrieved from its database (PICMS) for analysis.

Results

Totally 4338 poisoned cases were analysed. There were 1955 male patients (45.1%), 2,367 female patients (54.6%) and 16 patients with no gender specified. More than two-third of cases (68.6%) were between 20 and 59 years old. Common causes of exposure were suspected self harm/suicidal attempt, abusive use and unintentional exposure. Paracetamol, ketamine, zopiclone, benzodiazepine and household products were the common poisons exposed. Majority of the patients were managed supportively, with 13.6% and 13.1% treated by decontamination and antidotes respectively. Most cases had uneventful recovery; about 1% of the poison exposure resulted in death and about 5% of the exposure had major outcomes.

Conclusions

The 2009 annual report provides updated epidemiological information on poisoning pattern in Hong Kong and emphasized some changes in comparing with our previous reports.

Hong Kong Poison Information Centre: Annual Report 2010

Objective

To report and analyse the poisoning data of Hong Kong Poison Information Centre (HKPIC) in 2010.

Methods

In 2010, all poisoning cases received by HKPIC were retrieved from its database (PICMS) for analysis.

Results

A total of 4,418 poisoned cases were analysed. There were 1,863 male patients (42.2%) and 2,540 female patients (57.5%). More than two-third of cases (68.3%) were between 20 and 59 years old. Common causes of exposure were suspected self harm/suicidal attempt, unintentional exposure and abusive use. Benzodiazepine, paracetamol, ketamine, zopiclone, and Chinese herbal medicine were the common agents involved. Majority of the patients were managed supportively, with 10.2% and 9.7% treated by decontamination and antidotes respectively. Most cases had uneventful recovery; 1.0% of the poison exposure resulted in death and 5.3% of the exposure had major outcomes.

Conclusions

This fifth annual report provides updated epidemiological information on poisoning pattern in Hong Kong and emphasized some changes in comparing with our previous reports.

A Case of Methanol Poisoning

A 29-year-old male took about 300 ml industrial alcohol in a suicidal attempt. The industrial alcohol was later confirmed to be methanol. He presented to the emergency department 10 hours post-ingestion with an anion gap metabolic acidosis and an osmol gap of 76.7 mOsm/kg. Ethanol infusion was started in the emergency department at 11 hours post-ingestion before the availability of serum methanol level. The clinical diagnosis of toxic alcohol ingestion was based on the history, arterial blood gases results and the presence of a significant osmol gap. The patient was then admitted to the intensive care unit for ethanol therapy and haemodialysis. Prompt initiation of ethanol therapy and the subsequent intensive care prevented the development of life-threatening complications of methanol poisoning in this case.

A Prospective Epidemiological Study of Acute Poisoning in Hong Kong

Objective

To update our epidemiological knowledge of acute poisoning in Hong Kong.

Methods

A multi-centred prospective study was conducted for six months in six major accident and emergency departments in Hong Kong. A specially designed form was used to collect demographic data, type of poison involved, cause of poisoning, management, disposal as well as final outcome of the poisoned patients.

Results

A total of 1,467 patients (male: 588, female: 879) were included in the study. Most of them were young adults (32% were between 20 and 40 years old). Suicidal attempt (64%) was the most common cause of poisoning. Notably, 379 (26%) patients took more than one poison. Among the 2,007 counts of poison taken, sleeping pills (24%) and analgesics (18%) were the most commonly used drugs and paracetamol was the commonest single ingredient involved in poisoning. Most patients were treated with supportive measures, and about 40% and 15% of the patients were given gastrointestinal decontamination and specific antidotes respectively in their management, in which activated charcoal and N-acetylcysteine were the most common. Concerning disposal from the emergency department, 91% of the poisoned cases required in-patient management. Most patients had an uneventful recovery but 5 (0.3%) had significant disability and 21 (1.4%) died. Suicidal carbon monoxide poisoning was the leading cause of mortality in our study.

Conclusions

Most acute poisonings in Hong Kong were suicidal in nature and paracetamol was the commonest agent. Activated charcoal was the most commonly used decontamination method and most patients had an uneventful recovery.

Hong Kong Poison Information Centre: Annual Report 2013

Objective

To report and analyse the poisoning data of Hong Kong Poison Information Centre (HKPIC) in 2013.

Methods

In 2013, all poisoning cases received by HKPIC were retrieved from its database [Poison Information and Clinical Management System (PICMS)] for analysis.

Results

A total of 3,783 poisoned cases were analysed. There were 1,595 male patients (42.2%), 2,185 female patients (57.8%) and 3 sex unspecified patients (0.1%). Middle aged group (30-39 years) composed about one-fifth (20.8%) of the poisoning cases while about two-third (66.8%) of them were between 20 and 59 years old. Common causes for poisoning were suspected self-harm/suicidal attempt (43%), unintentional exposure (15.3%) and abusive substances use (14.5%). Five commonest types of poison exposed were paracetamol, benzodiazepine, zopiclone, household products and Chinese herbal medicine. Majority of the patients were managed with supportive measures, and 13.2% and 10.8% of them were treated by decontamination and antidotes respectively. Most cases had uneventful recovery; 0.9% of the poisoning resulted in death and 4.3% had major outcomes.

Conclusions

This 8th annual report provided updated epidemiological information on poisoning pattern in Hong Kong and highlighted important changes in comparing with our previous reports. (Hong Kong j. emerg.med. 2014;21:249-259)

Clinical Experience in the Use of Intravenous Lipid Emulsion in Hydroychloroquine and Chloroquine Overdose with Refractory Shock

Hydroxychloroquine overdose is a rare condition and often results in severe cardiovascular toxicities. We report 2 cases of fatal hydroxychloroquine overdose (1 patient had co-ingestion of chloroquine). Both patients developed refractory cardiovascular collapse and cardiac arrest soon after the drug overdose. Both of them were treated with high dose adrenaline and diazepam. However, they deteriorated rapidly despite the treatments. In view of similar toxicological profile of hydroxychloroquine to other lipophilic cardiotoxic medications, intravenous lipid emulsion was given as the last resort but both of them died eventually. Based on the clinical experience from these 2 cases, Intravenous lipid emulsion is not effective in reversing the cardiotoxic effects of hydroxychloroquine and chloroquine overdose.

Case Report: Paracetamol Poisoning in a 2-Year-Old Child – from International Overview to the Role of the Hong Kong Poison Information Centre

We report a 2-year-old girl suffering from acute liver failure as a result of paracetamol poisoning. The child successfully recovered after intensive care. We performed literature search for the past decade and found that the pathophysiological response in the child was different from that of the adult. Despite paracetamol poisoning being one of the most common poisonings in the world, there is still no consensus in the treatment protocol. Hence the role of the Hong Kong Poison Information Centre is briefly discussed.

Hong Kong Poison Information Centre: Annual Report 2011

Objective

To report and analyse the poisoning data of Hong Kong Poison Information Centre (HKPIC) in 2011.

Methods

In 2011, all poisoning cases received by HKPIC were retrieved from its database: Poison Information and Clinical Management System (PICMS) for analysis.

Results

A total of 4,331 poisoned cases were analysed. There were 1,915 male patients (44.2%), 2,411 female patients (55.7%) and 5 patients with sex unknown. More than two-third (68%) of them were between 20 and 59 years old. Common causes of exposure were suspected self-harm/suicidal attempt, unintentional exposure and abusive use. Paracetamol, benzodiazepine, household product, zopiclone, and Chinese herbal medicine were the top five commonest poisons encountered. Majority of the patients were managed supportively, with 12.1% and 8.5% treated by decontamination and antidotes respectively. Most cases had uneventful recovery; 1.0% of the poison exposure resulted in death and 4.8% of the exposure had major outcomes.

Conclusions

This 6th annual report provided updated epidemiological information on poisoning pattern in Hong Kong and emphasized some changes in comparing with our previous reports.

Two Cases of Anticholinergic Poisoning from Transdermal Scopolamine Patch

Scopolamine transdermal patch is a form of anticholinergic drug used to prevent motion sickness. We reported two cases of anticholinergic poisoning resulting from scopolamine transdermal patch. The first case experienced local toxicity and presented with right eye mydriasis for five days. The second case developed systemic anticholinergic toxidrome contributed by the scopolamine patch and presented with acute confusion. She was treated successfully by physostigmine, an anticholinergic antidote. The recommendation on physostigmine use was also discussed. We hope that these two case reports will raise the clinician awareness of the potential side effect of this kind of product.

Hong Kong Poison Information Centre: Annual Report 2006

Objective

To report the poisoning data of Hong Kong Poison Information Centre (HKPIC) in 2006.

Methods

From 1st January 2006 to 31st December 2006, all poisoning cases received by HKPIC were retrieved from its database (DATOX) for analysis.

Results

A total of 2555 poisoned cases were analysed. There were 1051 male and 1466 female patients and nearly 60% of the cases were between 20 and 49 years old. Common causes of exposure were suicidal attempts and accidents. Paracetamol, sedative-hypnotic and household products were common sources of poison exposure. The majority of the patients were managed conservatively, with 18.8% and 10.5% treated by decontamination and antidotes respectively. Most cases had uneventful recovery; less than 1% of the poison exposure resulted in death and about 5% of the exposure had major outcomes. Nearly half of the cases were managed in the accident & emergency department without hospitalisation.

Conclusions

This annual report provides updated epidemiological information on poisoning in Hong Kong. Subsequent annual reports would provide important information on the trend of poisoning pattern and may guide further strategies in poison control and prevention in Hong Kong.

A Study of Drug Radiopacity by Plain Radiography

Plain abdominal X-ray (AXR) may be helpful in the management of acute poisoning in the emergency department if the drugs involved are radiopaque. There are varying radiopacity among different medications and even for the same medication from different manufacturers. Therefore, we performed this study to detect local drug radiopacity in Hong Kong. A total of 430 drugs under the formulary of the United Christian Hospital were tested by standard AXR (75 kV, 23 mA) in a specially designed box which corresponded to the soft tissue density of the abdomen. Two different radiologists classified the drug radiopacity into three grades. Eight drugs (1.9%) were graded as definitely radiopaque (ranitidine bismuth citrate, tripotassium dicitratobismuthate, Drixoral SR, amiodarone, ferrous sulphate, sodium chloride, calcium carbonate, and Cafertamin). Another 129 drugs (30.0%) were slightly radiopaque, including slow release drugs, neuroleptics, antacids, ionic salts, beta-blockers, tricyclic antidepressants, antibiotics and others. The remaining 293 drugs were undetectable. As a significant number of drugs (31.9%) were detectable by plain AXR in vitro and some of them were potentially lethal, we should consider AXR as an adjunct in managing a suspected poisoned patient. Further study may be needed to evaluate these drugs' radiopacity in vivo with respect to the dosage and time of ingestion to assess its clinical application.

Hong Kong Poison Information Centre: Annual Report 2012

Objective

To report and analyze the poisoning data of Hong Kong Poison Information Centre (HKPIC) in 2012.

Methods

In 2012, all poisoning cases received by HKPIC were retrieved from its database: Poison Information and Clinical Management System (PICMS) for analysis.

Results

A total of 4,814 poisoned cases were analyzed. There were 1,771 male patients (42.3%), 2,399 female patients (57.3%) and 14 sex unspecified patients (0.3%). Middle aged group (30-39 years) contributed about one-fifth (20.1%) of the poisoning cases while more than two-third (67.7%) of them were between 20 and 59 years old. Common causes for poisoning were suspected self-harm/suicidal attempt (45%), abusive substances use (13.9%) and unintentional exposure (13.0%). Five commonest types of poison exposed were paracetamol, benzodiazepine, zopiclone, bites and envenomation and household products. Majority of the patients were managed with supportive measures, and 15.7% and 11.9% of them were treated by decontamination and antidotes respectively. Most cases had uneventful recovery; 0.6% of the poison exposure resulted in death and 4.7% of the exposure had major outcomes.

Conclusions

This seventh annual report provides updated epidemiological information on poisoning pattern in Hong Kong and highlights important changes in comparing with our previous reports. (Hong Kong j.emerg.med. 2013;20:371-381)

Maximizing T c by tuning nematicity and magnetism in FeSe1-x S x superconductors

A fundamental issue concerning iron-based superconductivity is the roles of electronic nematicity and magnetism in realising high transition temperature (T c). To address this issue, FeSe is a key material, as it exhibits a unique pressure phase diagram involving non-magnetic nematic and pressure-induced antiferromagnetic ordered phases. However, as these two phases in FeSe have considerable overlap, how each order affects superconductivity remains perplexing. Here we construct the three-dimensional electronic phase diagram, temperature (T) against pressure (P) and isovalent S-substitution (x), for FeSe1-x S x . By simultaneously tuning chemical and physical pressures, against which the chalcogen height shows a contrasting variation, we achieve a complete separation of nematic and antiferromagnetic phases. In between, an extended non-magnetic tetragonal phase emerges, where T c shows a striking enhancement. The completed phase diagram uncovers that high-T c superconductivity lies near both ends of the dome-shaped antiferromagnetic phase, whereas T c remains low near the nematic critical point.

CMTM6 maintains the expression of PD-L1 and regulates anti-tumour immunity

Cancer cells exploit the expression of the programmed death-1 (PD-1) ligand 1 (PD-L1) to subvert T-cell-mediated immunosurveillance. The success of therapies that disrupt PD-L1-mediated tumour tolerance has highlighted the need to understand the molecular regulation of PD-L1 expression. Here we identify the uncharacterized protein CMTM6 as a critical regulator of PD-L1 in a broad range of cancer cells, by using a genome-wide CRISPR-Cas9 screen. CMTM6 is a ubiquitously expressed protein that binds PD-L1 and maintains its cell surface expression. CMTM6 is not required for PD-L1 maturation but co-localizes with PD-L1 at the plasma membrane and in recycling endosomes, where it prevents PD-L1 from being targeted for lysosome-mediated degradation. Using a quantitative approach to profile the entire plasma membrane proteome, we find that CMTM6 displays specificity for PD-L1. Notably, CMTM6 depletion decreases PD-L1 without compromising cell surface expression of MHC class I. CMTM6 depletion, via the reduction of PD-L1, significantly alleviates the suppression of tumour-specific T cell activity in vitro and in vivo. These findings provide insights into the biology of PD-L1 regulation, identify a previously unrecognized master regulator of this critical immune checkpoint and highlight a potential therapeutic target to overcome immune evasion by tumour cells.

Click chemistry enables preclinical evaluation of targeted epigenetic therapies

The success of new therapies hinges on our ability to understand their molecular and cellular mechanisms of action. We modified BET bromodomain inhibitors, an epigenetic-based therapy, to create functionally conserved compounds that are amenable to click chemistry and can be used as molecular probes in vitro and in vivo. We used click proteomics and click sequencing to explore the gene regulatory function of BRD4 (bromodomain containing protein 4) and the transcriptional changes induced by BET inhibitors. In our studies of mouse models of acute leukemia, we used high-resolution microscopy and flow cytometry to highlight the heterogeneity of drug activity within tumor cells located in different tissue compartments. We also demonstrate the differential distribution and effects of BET inhibitors in normal and malignant cells in vivo. This study provides a potential framework for the preclinical assessment of a wide range of drugs.

Spontaneous Retroperitoneal Hematoma Simulating Ruptured Infrarenal Aortic Aneurysm in a Patient with End-Stage Renal Disease

We reported a case of spontaneous retroperitoneal hematoma (SRH) simulating a ruptured infrarenal aortic aneurysm. A 72-year-old man with a history of infrarenal aortic aneurysm and end-stage renal disease on hemodialysis presented with malaise and nonspecific central abdominal pain and left loin discomfort. An emergency computed tomography scan showed a large retroperitoneal hematoma and clinical suspicion of ruptured infrarenal aortic aneurysm. However, the hematoma was discontinuous with the aneurysm sac and raised the clinical suspicion on dual pathology. The SRH was treated conservatively with transfusion of blood products, and the aneurysm was treated with nonemergency endovascular repair electively. This case demonstrates the importance of recognizing different clinical and radiological characteristics and be aware of dual pathology.

Omalizumab reduces bronchial mucosal IgE and improves lung function in non-atopic asthma

Omalizumab therapy of non-atopic asthmatics reduces bronchial mucosal IgE and inflammation and preserves/improves lung function when disease is destabilised by staged withdrawal of therapy.

18 symptomatic, non-atopic asthmatics were randomised (1:1) to receive omalizumab or identical placebo treatment in addition to existing therapy for 20 weeks. Bronchial biopsies were collected before and after 12–14 weeks of treatment, then the patients destabilised by substantial, supervised reduction of their regular therapy. Primary outcome measures were changes in bronchial mucosal IgE+ cells at 12–14 weeks, prior to regular therapy reduction, and changes in lung function (forced expiratory volume in 1 s) after destabilisation at 20 weeks. Quality of life was also monitored.

Omalizumab but not placebo therapy significantly reduced median total bronchial mucosal IgE+ cells (p<0.01) but did not significantly alter median total mast cells, plasma cells, B lymphocytes, eosinophils and plasmablasts, although the latter were difficult to enumerate, being distributed as disperse clusters. By 20 weeks, lung function declined in the placebo-treated patients but improved in the omalizumab treated patients, with significant differences in absolute (p=0.04) and % predicted forced expiratory volume in 1 s (p=0.015).

Omalizumab therapy of non-atopic asthmatics reduces bronchial mucosal IgE+ mast cells and improves lung function despite withdrawal of conventional therapy.

Antibodies and superantibodies in patients with chronic rhinosinusitis with nasal polyps

Background

Chronic rhinosinusitis with nasal polyps is associated with local immunoglobulin hyperproduction and the presence of IgE antibodies against Staphylococcus aureus enterotoxins (SAEs). Aspirin-exacerbated respiratory disease is a severe form of chronic rhinosinusitis with nasal polyps in which nearly all patients express anti-SAEs.

Objectives

We aimed to understand antibodies reactive to SAEs and determine whether they recognize SAEs through their complementarity-determining regions (CDRs) or framework regions.

Methods

Labeled staphylococcal enterotoxin (SE) A, SED, and SEE were used to isolate single SAE-specific B cells from the nasal polyps of 3 patients with aspirin-exacerbated respiratory disease by using fluorescence-activated cell sorting. Recombinant antibodies with “matched” heavy and light chains were cloned as IgG₁, and those of high affinity for specific SAEs, assayed by means of ELISA and surface plasmon resonance, were recloned as IgE and antigen-binding fragments. IgE activities were tested in basophil degranulation assays.

Results

Thirty-seven SAE-specific, IgG- or IgA-expressing B cells were isolated and yielded 6 anti-SAE clones, 2 each for SEA, SED, and SEE. Competition binding assays revealed that the anti-SEE antibodies recognize nonoverlapping epitopes in SEE. Unexpectedly, each anti-SEE mediated SEE-induced basophil degranulation, and IgG₁ or antigen-binding fragments of each anti-SEE enhanced degranulation by the other anti-SEE.

Conclusions

SEEs can activate basophils by simultaneously binding as antigens in the conventional manner to CDRs and as superantigens to framework regions of anti-SEE IgE in anti-SEE IgE-FcεRI complexes. Anti-SEE IgG₁s can enhance the activity of anti-SEE IgEs as conventional antibodies through CDRs or simultaneously as conventional antibodies and as “superantibodies” through CDRs and framework regions to SEEs in SEE–anti-SEE IgE-FcεRI complexes.