Streamlining lung cancer management in Nova Scotia amid COVID-19: pooled triaging for expedited curative-intent oncologic surgery.

BACKGROUND: The effect of the COVID-19 pandemic on the diagnosis and management of lung cancer in Canada is not fully understood. We sought to quantify the provincial volume of diagnostic imaging, thoracic surgeon referrals, time to surgery after referral, and pathologic staging for curative surgery in the context of the pandemic, as well as explore the effect of a pooled patient model, which was implemented to prioritize surgeries for lung cancer and mitigate the effects of the pandemic. METHODS: We conducted a retrospective cohort study of patients who underwent diagnostic imaging in Nova Scotia and were subsequently referred to a thoracic surgeon at the province's only tertiary care centre for surgical management of their primary lung cancer before (Mar. 1, 2019, to Feb. 29, 2020) and during (Mar. 1, 2020, to Feb. 28, 2021) the COVID-19 pandemic. We conducted a survey to capture the patient and surgeon experience with a pooled patient model of managing surgical oncology cases. RESULTS: Compared with the pre-COVID-19 period, the overall volume of chest radiography and chest computed tomography decreased by 30.9% (p < 0.001) and 18.7% (p = 0.002), respectively, in the COVID-19 period. Thoracic surgeon referrals, operative approach, extent of resection, length of hospital stay, and pathologic staging did not significantly differ. Time from referral to surgery was significantly shorter during the COVID-19 period (mean 196.8 d v. 157.9 d, p = 0.04). A pooled patient approach contributed to positive patient satisfaction. CONCLUSION: The COVID-19 pandemic was associated with reductions in rates of diagnostic imaging and referrals to thoracic surgeons for management of pulmonary cancer. A pooled patient model was used to mitigate the effects of the pandemic on lung cancer management and was positively received by patients. An extended study period is needed to determine the full effect of this redistribution of resources.

Patterns of primary and specialty care among children with sickle cell anemia.

BACKGROUND AND OBJECTIVE: National guidelines recommend that children with sickle cell anemia (SCA) be seen regularly by primary care providers (PCPs) as well as hematologists to receive comprehensive, multidisciplinary care. The objective is to characterize the patterns of primary and hematology care for children with SCA in Michigan. METHODS: Using validated claims definitions, children ages 1-17 years with SCA were identified using Michigan Medicaid administrative claims from 2010 to 2018. We calculated the number of outpatient PCP and hematologist visits per person-year, as well as the proportion of children with at least one visit to a PCP, hematologist, or both a PCP and hematologist annually. Negative binomial regression was used to calculate annual rates of visits for each provider type. RESULTS: A total of 875 children contributed 2889 person-years. Of the total 22,570 outpatient visits, 52% were with a PCP and 34% with a hematologist. Annually, 87%-93% of children had a visit with a PCP, and 63%-85% had a visit with a hematologist. Approximately 66% of total person-years had both visit types within a year. The annual rate ranged from 2.3 to 2.5 for hematologist visits and from 3.7 to 4.1 for PCP visits. CONCLUSIONS: Substantial gaps exist in the receipt of annual hematology care. Given that the majority of children with SCA see a PCP annually, strategies to leverage primary care visits experienced by this population may be needed to increase receipt of SCA-specific services.

Inhibition of the mPTP and Lipid Peroxidation Is Additively Protective Against I/R Injury.

BACKGROUND: During myocardial ischemia/reperfusion (I/R) injury, high levels of matrix Ca2+ and reactive oxygen species (ROS) induce the opening of the mitochondrial permeability transition pore (mPTP), which causes mitochondrial dysfunction and ultimately necrotic death. However, the mechanisms of how these triggers individually or cooperatively open the pore have yet to be determined. METHODS: Here, we use a combination of isolated mitochondrial assays and in vivo I/R surgery in mice. We challenged isolated liver and heart mitochondria with Ca2+, ROS, and Fe2+ to induce mitochondrial swelling. Using inhibitors of the mPTP (cyclosporine A or ADP) lipid peroxidation (ferrostatin-1, MitoQ), we determined how the triggers elicit mitochondrial damage. Additionally, we used the combination of inhibitors during I/R injury in mice to determine if dual inhibition of these pathways is additivity protective. RESULTS: In the absence of Ca2+, we determined that ROS fails to trigger mPTP opening. Instead, high levels of ROS induce mitochondrial dysfunction and rupture independently of the mPTP through lipid peroxidation. As expected, Ca2+ in the absence of ROS induces mPTP-dependent mitochondrial swelling. Subtoxic levels of ROS and Ca2+ synergize to induce mPTP opening. Furthermore, this synergistic form of Ca2+- and ROS-induced mPTP opening persists in the absence of CypD (cyclophilin D), suggesting the existence of a CypD-independent mechanism for ROS sensitization of the mPTP. These ex vivo findings suggest that mitochondrial dysfunction may be achieved by multiple means during I/R injury. We determined that dual inhibition of the mPTP and lipid peroxidation is significantly more protective against I/R injury than individually targeting either pathway alone. CONCLUSIONS: In the present study, we have investigated the relationship between Ca2+ and ROS, and how they individually or synergistically induce mitochondrial swelling. Our findings suggest that Ca2+ mediates mitochondrial damage through the opening of the mPTP, although ROS mediates its damaging effects through lipid peroxidation. However, subtoxic levels both Ca2+ and ROS can induce mPTP-mediated mitochondrial damage. Targeting both of these triggers to preserve mitochondria viability unveils a highly effective therapeutic approach for mitigating I/R injury.

A Review of Recent Low-dose Research and Recommendations for Moving Forward.

ABSTRACT: The linear no-threshold (LNT) model has been the regulatory "law of the land" for decades. Despite the long-standing use of LNT, there is significant ongoing scientific disagreement on the applicability of LNT to low-dose radiation risk. A review of the low-dose risk literature of the last 10 y does not provide a clear answer, but rather the body of literature seems to be split between LNT, non-linear risk functions (e.g., supra- or sub-linear), and hormetic models. Furthermore, recent studies have started to explore whether radiation can play a role in the development of several non-cancer effects, such as heart disease, Parkinson's disease, and diabetes, the mechanisms of which are still being explored. Based on this review, there is insufficient evidence to replace LNT as the regulatory model despite the fact that it contributes to public radiophobia, unpreparedness in radiation emergency response, and extreme cleanup costs both following radiological or nuclear incidents and for routine decommissioning of nuclear power plants. Rather, additional research is needed to further understand the implications of low doses of radiation. The authors present an approach to meaningfully contribute to the science of low-dose research that incorporates machine learning and Edisonian approaches to data analysis.

Extraintestinal Manifestations and Family History of Inflammatory Bowel Disease Increase the Risk of Pouchitis in a State-Level Epidemiology Study.

INTRODUCTION: Our understanding of the epidemiology of inflammatory conditions of the pouch and effectiveness of treatment is largely based on selected populations. We created a state-level registry to evaluate the incidence of pouchitis and the effectiveness of treatments used in an initial episode of pouchitis. METHODS: In a state-level retrospective cohort of all patients undergoing proctocolectomy with ileal pouch-anal anastomosis (IPAA) for ulcerative colitis between January 1, 2018, and December 31, 2020, we evaluated the incidence of pouchitis and compared the proportion of patients developing recurrent pouchitis and chronic antibiotic-dependent pouchitis according to initial antibiotic therapy. RESULTS: A total of 177 patients underwent surgery with 49 (28%) developing pouchitis within the 12 months after the final stage of IPAA. Patients with extraintestinal manifestations of inflammatory bowel disease (IBD) were significantly more likely to develop pouchitis within the first 12 months after IPAA (adjusted odds ratio 2.45, 95% confidence interval 1.03-5.81) after adjusting for family history of IBD (adjusted odds ratio 3.50, 95% 1.50-8.18). When comparing the proportion of patients who developed recurrent pouchitis or chronic antibiotic-dependent pouchitis with those who experienced an isolated episode of pouchitis, there were no significant differences among the initial antibiotic regimens used. DISCUSSION: In a state-level examination of outcomes after IPAA for ulcerative colitis, patients with extraintestinal manifestations of IBD were more likely to develop pouchitis; however, the initial antibiotic regimen chosen did not seem to affect long-term outcomes.

Role of Temporomandibular Total Joint Replacement in Correction of Facial Deformities.

Introduction: Individuals suffering from facial deformities experience esthetic, functional and social setback in their lives every day. These patients benefit greatly with single-stage temporomandibular joint replacement along with orthognathic surgical procedures to correct functional as well as esthetic components. Methodology: Five individuals with facial deformities due to hemifacial macrosomia, fibrous dysplasia, idiopathic condylar resorption, ankylosis, etc., were treated with total joint replacement along with orthognathic surgical procedures for functional and esthetic correction. The customized temporomandibular joint was digitally custom designed, and the orthognathic procedures were virtually planned on NemoFAB software before performing the surgical procedure. Results: Intraoperatively, the overall time was reduced considerably with minimal unpredictable complications. One-week postoperative computed tomographs were obtained and superimposed on preoperative virtual surgical planning which showed minimal discrepancy. Follow-up period of 18-30 months was maintained for all the patients with stable results, minimal relapse and satisfactory functional abilities. Discussion: Total joint replacement along with orthognathic procedure provides single-stage functional and esthetic corrections for the patients, considerably improving their quality of life. Precise preoperative surgical planning proves to be an indispensable step for achieving desired results with minimal margin of error and avoid any unseen complications during the surgical procedure.

Conformation-selective rather than avidity-based binding to tumor associated antigen derived peptide-MHC enables targeting of WT1-pMHC low expressing cancer cells by anti-WT1-pMHC/CD3 T cell engagers.

T cell engagers, a category of T cell-retargeting immunotherapy, are rapidly transforming clinical cancer care. However, the lack of tumor-specific targets poses a significant roadblock for broad adaptation of this therapeutic modality in many indications, often resulting in systemic on-target off-tumor toxicity. Though various tumor-derived intracellular mutations provide a massive pool of potential tumor-specific antigens, targeting them is extremely challenging, partly due to the low copy number of tumor associated antigen (TAA)-derived pMHC on tumor cell surface. Further, the interplay of binding geometry and format valency in relation to the capacity of a T cell engager to efficiently target low density cell-surface pMHC is not well understood. Using the Wilms' tumor 1 (WT1) oncoprotein as a proof-of-principle TAA, combined with an array of IgG-like T cell engager modalities that differ in their anti-TAA valency and binding geometry, we show that the ability to induce an immunological synapse formation, resulting in potent killing of WT1 positive cancer cell lines is primarily dependent on the distinct geometrical conformations between the Fab arms of anti-WT1-HLA-A*02:01 and anti-CD3. The augmented avidity conferred by the binding of two anti-WT1-HLA-A*02:01 Fab arms has only minimal influence on cell killing potency. These findings demonstrate the need for careful examination of key design parameters for the development of next-generation T cell engagers targeting low density TAA-pMHCs on tumor cells.

Genetic separation of Brca1 functions reveal mutation-dependent Polθ vulnerabilities.

Homologous recombination (HR)-deficiency induces a dependency on DNA polymerase theta (Polθ/Polq)-mediated end joining, and Polθ inhibitors (Polθi) are in development for cancer therapy. BRCA1 and BRCA2 deficient cells are thought to be synthetic lethal with Polθ, but whether distinct HR gene mutations give rise to equivalent Polθ-dependence, and the events that drive lethality, are unclear. In this study, we utilized mouse models with separate Brca1 functional defects to mechanistically define Brca1-Polθ synthetic lethality. Surprisingly, homozygous Brca1 mutant, Polq-/- cells were viable, but grew slowly and had chromosomal instability. Brca1 mutant cells proficient in DNA end resection were significantly more dependent on Polθ for viability; here, treatment with Polθi elevated RPA foci, which persisted through mitosis. In an isogenic system, BRCA1 null cells were defective, but PALB2 and BRCA2 mutant cells exhibited active resection, and consequently stronger sensitivity to Polθi. Thus, DNA end resection is a critical determinant of Polθi sensitivity in HR-deficient cells, and should be considered when selecting patients for clinical studies.

Drug reaction with eosinophilia and systemic symptoms (DRESS): an unusual manifestation of multi-visceral abnormalities and long-term outcome.

Drug reaction with eosinophilia and systemic symptoms (DRESS), also known as drug induced hypersensitivity (DiHS) is a rare, however a severe hypersensitivity reaction with a mortality rate of up to 10%, accounting for 10 to 20% of all cutaneous drug reactions in hospitalized patients. The clinical features of DRESS/DiHS may be challenging to recognize and diagnose, since they are delayed, stepwise, and heterogeneous. The classic presentation of DRRSS/DiHS involves a combination of cutaneous, hematologic, and internal organ involvement with a 2 to 8 weeks latency between drug exposure and the onset of symptoms. Finding the culprit drug in our case was difficult as the patient was taking multiple antibiotics. Drugs such as vancomycin and cefepime used before the rash outbreak for post-reconstructive surgery for left toal knee arthroplasty (TKA) approximately four weeks before the onset of the rash are likely offending agents. This patient also had multi-visceral involvement with eosinophilia and systemic symptoms. The current treatment guidelines for DRESS/DiHS are primarily based on expert opinion, as no randomized control trials exist. After the prompt withdrawal of the offending drug, systemic corticosteroids seem to have shown the best outcome for patients. Delaying discontinuing offending medications and initiating corticosteroid treatment may lead to poor results. The present case emphasizes that the close observation of patients with drug eruption induced by antibiotics is imperative. Primary care team should be able to promptly diagnose patients with DRESS syndrome, detect causative drug, and play a crucial role in the timely evaluation and treatment to reduce mortality rate. The later phase disease relapse or autoimmune complications may occur up to 5 years following the initial presentation. Therefore, we advised the patient to have an outpatient follow up for appropriate testing, including but not limited to genetic susceptibility due to the high risk of relapse and emerging risk of autoimmune diseases.

Neurosyphilis Mimicking Connective Tissue Disease.

A male in his 60s developed a pruritic, maculopapular rash on his torso and arms, sparing his palms and soles. He tested positive for ANA and an initial skin biopsy identified "bullous lupus," supporting the diagnosis of a connective tissue disease. Additional symptoms included headaches, facial nerve palsy and hearing loss, which partially responded to oral corticosteroids. He subsequently developed a steroid-dependent left eye scotoma, neuroretinitis and optic nerve papillitis. Mycophenolate mofetil was added but an attempted oral steroid taper led to a worsening rash, progressive retinitis and papillitis. Neurosyphilis was confirmed by serum positive rapid plasma reagin test, reactive treponema pallidum antibodies, positive cerebrospinal fluid venereal disease research laboratory and positive spirochete immunostain of skin biopsy of lesional (rash) tissue. Treatment with intravenous ceftriaxone resolved his rash and visual symptoms. It is important to consider syphilis as a mimicker of connective tissue diseases.

Extensive Colitis and Smoking Are Associated With Postoperative Complications Within 30 Days of Ileal Pouch-Anal Anastomosis.

BACKGROUND: Our understanding of outcomes after proctocolectomy with ileal pouch-anal anastomosis (IPAA) for ulcerative colitis (UC) is largely based on analyses of selected populations. We created a state-level registry to evaluate the epidemiology of IPAA surgery and pouch-related outcomes across the major healthcare systems performing these surgeries in our state. METHODS: We created a retrospective cohort of all patients undergoing restorative proctocolectomy with IPAA for UC at 1 of 4 centers between January 1, 2018, and December 31, 2020. The primary outcomes of this study were the rate of complications and all-cause readmissions within the first 30 days of the final stage of IPAA surgery. RESULTS: During the study period, 177 patients underwent IPAA surgery with 66 (37%) experiencing a complication within 30 days. After adjusting for the number of stages in IPAA surgery, patients with extensive UC (odds ratio, 3.61; 95% confidence interval, 1.39-9.33) and current or former smokers (odds ratio, 2.98; 95% confidence interval, 1.38-6.45) were more likely to experience a complication. Among all patients, 57 (32%) required readmission within 30 days. The most common reasons for readmission were ileus/small bowel obstruction (22%), peripouch abscess (19%), and dehydration (16%). CONCLUSION: In this first state-level examination of the epidemiology of IPAA for UC, we demonstrated that the complication rate after IPAA for UC was 37%, with one-third of patients being readmitted within 30 days. Extensive disease at the time of colectomy appears to be an indicator of more severe disease and may portend a worse prognosis after IPAA.

Incidental Pulmonary Nodules and Lung Cancer Screening.

Incidental nodules and lung cancer screening nodules are causes of concern and anxiety for the patients. Both these require diligent follow up according to their respective guidelines.

BRCA1 secondary splice-site mutations drive exon-skipping and PARP inhibitor resistance.

BRCA1 splice isoforms Δ11 and Δ11q can contribute to PARP inhibitor (PARPi) resistance by splicing-out the mutation-containing exon, producing truncated, partially-functional proteins. However, the clinical impact and underlying drivers of BRCA1 exon skipping remain undetermined. We analyzed nine ovarian and breast cancer patient derived xenografts (PDX) with BRCA1 exon 11 frameshift mutations for exon skipping and therapy response, including a matched PDX pair derived from a patient pre- and post-chemotherapy/PARPi. BRCA1 exon 11 skipping was elevated in PARPi resistant PDX tumors. Two independent PDX models acquired secondary BRCA1 splice site mutations (SSMs), predicted in silico to drive exon skipping. Predictions were confirmed using qRT-PCR, RNA sequencing, western blots and BRCA1 minigene modelling. SSMs were also enriched in post-PARPi ovarian cancer patient cohorts from the ARIEL2 and ARIEL4 clinical trials. We demonstrate that SSMs drive BRCA1 exon 11 skipping and PARPi resistance, and should be clinically monitored, along with frame-restoring secondary mutations.

A Novel Method to Rehabilitate Post-mucormycosis Maxillectomy Defect by Using Patient-Specific Zygoma Implant.

Aim: During second wave of COVID pandemic, India faced heavy surge of mucormycosis. Treatment option for these patients included either total or partial maxillectomy with primary closure. Rehabilitation of these patients became challenging because of their age and size of defect. The purpose of the present study is to present a new digital technique for the fabrication of patient-specific zygoma implants (PSI) and to report on its survival and complication rates. Material and Methods: Total 21 patients who had undergone either partial or total maxillectomy after mucormycosis and who were disease-free clinically and radiographically for 6 or more months post-resection were rehabilitated using patient-specific zygoma implant. CT scan was obtained for all patients post-maxillectomy for evaluation of existing bone condition. Exocad software was used for virtual surgical planning of zygoma implant considering surgical and prosthetic technicality to achieve goal of maximum functionality and sustainability. Result: All the patients were followed up after 15, 30, 45 and 90 days and there after every month for evaluation of soft tissue healing, infection, dehiscence, loosening of prosthesis, eating efficiency and aesthetic. Follow-up period for all 15 patients was in the range of 6-12 months. Conclusion: In case of post-mucor maxillectomy patients, use of PSI offers the advantages of minimal bone augmentation, reduction in time required to restore lost function, and reduced financial burden of multiple procedures. Therefore, PSI may represent a valid alternative treatment for the prosthetic restoration of post-mucor maxillectomy patients.

A Systematic Review of Warfarin Use in Post-Bariatric Surgery Patients: Cases Compiled From a Literature Review.

OBJECTIVE: The objective of this review was to provide dosing recommendations for percentage change in weekly warfarin dose and rates of thrombotic and bleeding events in patients requiring long-term warfarin therapy after bariatric surgery. DATA SOURCES: A comprehensive literature search of PubMed (through April 5, 2021), Cochrane Library, and Google Scholar (through April 5, 2021) databases was completed using the keywords warfarin OR vitamin k antagonist AND bariatric surgery. STUDY SELECTION AND DATA EXTRACTION: Retrospective studies and matched-cohort studies evaluating preoperative and postoperative use of warfarin after bariatric surgery for obesity were considered. Weekly dose defined as sum of daily doses of warfarin for 7 consecutive days was a required outcome to be considered in this review. Patients were excluded from review if post-operative dosage change was not reported. DATA SYNTHESIS: Six studies were included with a total of 160 patients who met the criteria. A decrease in average warfarin dose was seen in all studies, with the largest decrease occurring at 1 month postsurgery followed by an upward trend toward baseline about 90 days postsurgery. While thrombotic events were observed in none of the patients, there was an increased risk of bleeding in patients, particularly in those who underwent roux-en-y gastric bypass (RYGB) surgery. RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE: The study provides a specific warfarin dosing titration regimen, as well as embolic and bleed risk in post-bariatric surgery population. CONCLUSIONS: Clinicians may consider lowering warfarin weekly dose by about 25% immediately postsurgery, with doses approaching closer to baseline about 90 days postsurgery.

The Development and Mechanistic Study of an Iron-Catalyzed Intramolecular Nitroso Ene Reaction of Nitroarenes.

An intramolecular iron-catalyzed nitroso ene reaction was developed to afford six- or seven-membered N-heterocycles from nitroarenes using an earth abundant iron catalyst and phenylsilane as the terminal reductant. The reaction can be triggered using as little as 3 mol % of iron(II) acetate and 3 mol % of 4,7-dimethoxyphenanthroline as the ligand. The scope of the reaction is broad tolerating a range of electron-releasing or electron-withdrawing substituents on the nitroarene, and the ortho-substituent can be modified to diastereoselectively construct benzoxazines, dihydrobenzothiazines, tetrahydroquinolines, tetrahydroquinoxalines, or tetrahydrobenzooxazepines. Mechanistic investigations indicated that the reaction proceeds via a nitrosoarene intermediate, and kinetic analysis of the reaction revealed a first-order rate dependence in catalyst-, nitroarene-, and silane concentration, and an inverse kinetic order in acetate was observed. The difference in rates between PhSiH3 and PhSiD3 was found to be 1.50 ± 0.09, and investigation of the temperature dependence of the reaction rate revealed that the activation parameters to be ΔH‡ = 13.5 kcal•mol-1 and ΔS‡ = -39.1 cal•mol-1•K-1. These data were interpreted to indicate that the turnover-limiting step to be hydride transfer from iron to the coordinated nitroarene, which occurs through an ordered transition state with little Fe-H bond breaking.

Spectrum of thyroid disease in a single patient: A case of papillary thyroid carcinoma in a patient with Graves' disease and Hashimoto's thyroiditis.

A 65-year-old man with a history of Hashimoto's thyroiditi on Levothyroxine developed Graves' disease with ocular symptoms and was treated with teprotumumab without improvement. Total thyroidectomy was performed to control hyperthyroidism. Surgical pathology revealed multifocal papillary thyroid carcinoma. Rarely, a spectrum of thyroid disorders is seen in a single patient.

Drug-Induced Hyperthermia Review.

Humans maintain core body temperature via a complicated system of physiologic mechanisms that counteract heat/cold fluctuations from metabolism, exertion, and the environment. Overextension of these mechanisms or disruption of body temperature homeostasis leads to bodily dysfunction, culminating in a syndrome analogous to exertional heat stroke (EHS). The inability of this thermoregulatory process to maintain the body temperature is caused by either thermal stress or certain drugs. EHS is a syndrome characterized by hyperthermia and the activation of systemic inflammation. Several drug-induced hyperthermic syndromes may resemble EHS and share common mechanisms. The purpose of this article is to review the current literature and compare exertional heat stroke (EHS) to three of the most widely studied drug-induced hyperthermic syndromes: malignant hyperthermia (MH), neuroleptic malignant syndrome (NMS), and serotonin syndrome (SS). Drugs and drug classes that have been implicated in these conditions include amphetamines, diuretics, cocaine, antipsychotics, metoclopramide, selective serotonin reuptake inhibitors (SSRIs), tricyclic antidepressants (TCAs), and many more. Observations suggest that severe or fulminant cases of drug-induced hyperthermia may evolve into an inflammatory syndrome best described as heat stroke. Their underlying mechanisms, symptoms, and treatment approaches will be reviewed to assist in accurate diagnosis, which will impact the management of potentially life-threatening complications.

Checkpoint inhibitor-associated bullous cutaneous immune-related adverse events: a multicentre observational study.

BACKGROUND: Checkpoint inhibitor (CPI) therapy has significantly improved overall survival in several cancers including metastatic melanoma (MM) and in the adjuvant setting. Cutaneous immune-related adverse events (irAEs) secondary to CPIs are commonly observed; however, autoimmune blistering disorders such as bullous pemphigoid (BP) are rare. OBJECTIVES: To review the prevalence, incidence risk, clinicopathological features and management of toxicity in bullous cutaneous irAEs associated with CPI therapy. METHODS: A multicentre, retrospective, observational study of CPI-associated bullous irAEs in adults with all cancers across four UK specialist centres between 2006 and 2019. RESULTS: In total, 7391 patients were identified. CPI-associated bullous irAEs including BP (n = 16) occurred in 0·3% (n = 22). The median age of onset was 76 years, and there was a male predominance. Most patients had cutaneous melanoma (73%, n = 16), of which 81% (13 of 16) were BRAF wildtype. Grade 1, 2, 3 and 4 skin toxicity occurred in 9%, 45%, 41% and 5%, respectively. The mucosae were involved in 27%, and 25% of confirmed cases of BP did not present with bullae. The median time to onset of bullous irAEs was 12 months, with a median total symptom duration of 6 months. Single PD-1/PD-L1 agents had a longer time to onset of symptoms than combination therapy (median 12 vs. 7 months, respectively). Overall, 91%, 64% and 9% of patients required one, two or three lines of treatment, respectively. Two cases occurred after completion of CPIs (1 and 3 months). Of the 20 cases that presented while on CPIs this was permanently discontinued in 55% (11 of 20) and temporarily held in 20% (four of 20). In the four held cases of CPI, bullous eruption reflared in 50%. CONCLUSIONS: CPI-associated bullous skin toxicity is a rare cutaneous irAE occurring in approximately 0·3% of cases over 13 years of treated patients in this series. Not all cases are diagnostic of BP, but management remains the same. There is a prolonged latency of onset compared with other cutaneous irAEs, with a median time of 12 months, and they can occur after cessation of therapy. Discontinuation of CPIs may be required. Recognizing bullous irAEs promptly and referral to dermatology are essential to optimize management and improve patient outcomes and tumour responses. What is already known about this topic? Checkpoint inhibitor (CPI)-associated bullous pemphigoid is a rare dermatological immune-related adverse event (irAE) that has been reported in small case series and reports. What does this study add? This is the largest multicentre, observational study conducted in the UK over the longest period of 13 years, which demonstrates an overall incidence of bullous cutaneous irAEs secondary to CPIs of 0·3%. Clinical presentation is variable, with one-quarter of patients with bullous pemphigoid presenting without bullae, and mucosal involvement was noted in 27%. Prolonged pruritus is frequently a prodromal symptom. The median time to diagnosis is 12 months and irAEs rarely present after cessation of treatment. Time to onset of symptoms is longer with a single CPI, but with a shorter duration of symptoms compared with combination CPI therapy. Most patients had cutaneous melanoma, of which 81% were BRAF wildtype.

High-resolution profiling of MHC II peptide presentation capacity reveals SARS-CoV-2 CD4 T cell targets and mechanisms of immune escape.

Understanding peptide presentation by specific MHC alleles is fundamental for controlling physiological functions of T cells and harnessing them for therapeutic use. However, commonly used in silico predictions and mass spectroscopy have their limitations in precision, sensitivity, and throughput, particularly for MHC class II. Here, we present MEDi, a novel mammalian epitope display that allows an unbiased, affordable, high-resolution mapping of MHC peptide presentation capacity. Our platform provides a detailed picture by testing every antigen-derived peptide and is scalable to all the MHC II alleles. Given the urgent need to understand immune evasion for formulating effective responses to threats such as SARS-CoV-2, we provide a comprehensive analysis of the presentability of all SARS-CoV-2 peptides in the context of several HLA class II alleles. We show that several mutations arising in viral strains expanding globally resulted in reduced peptide presentability by multiple HLA class II alleles, while some increased it, suggesting alteration of MHC II presentation landscapes as a possible immune escape mechanism.