Long term peripheral AAV9-SMN gene therapy promotes survival in a mouse model of spinal muscular atrophy.

Spinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disease characterized by motor neuron loss and skeletal muscle atrophy. SMA is caused by the loss of the SMN1 gene and low SMN protein levels. Current SMA therapies work by increasing SMN protein in the body. Although SMA is regarded as a motor neuron disorder, growing evidence shows that several peripheral organs contribute to SMA pathology. A gene therapy treatment, onasemnogene abeparvovec, is being explored in clinical trials via both systemic and central nervous system (CNS) specific delivery, but the ideal route of delivery as well as the long-term effectiveness is unclear. To investigate the impact of gene therapy long term, we assessed SMA mice at 6 months after treatment of either intravenous (IV) or intracerebroventricular (ICV) delivery of scAAV9-cba-SMN. Interestingly, we observed that SMN protein levels were restored in the peripheral tissues but not in the spinal cord at 6 months of age. However, ICV injections provided better motor neuron and motor function protection than IV injection, while IV-injected mice demonstrated better protection of neuromuscular junctions and muscle fiber size. Surprisingly, both delivery routes resulted in an equal rescue on survival, weight, and liver and pancreatic defects. These results demonstrate that continued peripheral AAV9-SMN gene therapy is beneficial for disease improvement even in the absence of SMN restoration in the spinal cord.

Optimization of base editors for the functional correction of SMN2 as a treatment for spinal muscular atrophy.

Spinal muscular atrophy (SMA) is caused by mutations in SMN1. SMN2 is a paralogous gene with a C•G-to-T•A transition in exon 7, which causes this exon to be skipped in most SMN2 transcripts, and results in low levels of the protein survival motor neuron (SMN). Here we show, in fibroblasts derived from patients with SMA and in a mouse model of SMA that, irrespective of the mutations in SMN1, adenosine base editors can be optimized to target the SMN2 exon-7 mutation or nearby regulatory elements to restore the normal expression of SMN. After optimizing and testing more than 100 guide RNAs and base editors, and leveraging Cas9 variants with high editing fidelity that are tolerant of different protospacer-adjacent motifs, we achieved the reversion of the exon-7 mutation via an A•T-to-G•C edit in up to 99% of fibroblasts, with concomitant increases in the levels of the SMN2 exon-7 transcript and of SMN. Targeting the SMN2 exon-7 mutation via base editing or other CRISPR-based methods may provide long-lasting outcomes to patients with SMA.

Base editing as a genetic treatment for spinal muscular atrophy.

Spinal muscular atrophy (SMA) is a devastating neuromuscular disease caused by mutations in the SMN1 gene. Despite the development of various therapies, outcomes can remain suboptimal in SMA infants and the duration of such therapies are uncertain. SMN2 is a paralogous gene that mainly differs from SMN1 by a C•G-to-T•A transition in exon 7, resulting in the skipping of exon 7 in most SMN2 transcripts and production of only low levels of survival motor neuron (SMN) protein. Genome editing technologies targeted to the SMN2 exon 7 mutation could offer a therapeutic strategy to restore SMN protein expression to normal levels irrespective of the patient SMN1 mutation. Here, we optimized a base editing approach to precisely edit SMN2, reverting the exon 7 mutation via an A•T-to-G•C base edit. We tested a range of different adenosine base editors (ABEs) and Cas9 enzymes, resulting in up to 99% intended editing in SMA patient-derived fibroblasts with concomitant increases in SMN2 exon 7 transcript expression and SMN protein levels. We generated and characterized ABEs fused to high-fidelity Cas9 variants which reduced potential off-target editing. Delivery of these optimized ABEs via dual adeno-associated virus (AAV) vectors resulted in precise SMN2 editing in vivo in an SMA mouse model. This base editing approach to correct SMN2 should provide a long-lasting genetic treatment for SMA with advantages compared to current nucleic acid, small molecule, or exogenous gene replacement therapies. More broadly, our work highlights the potential of PAMless SpRY base editors to install edits efficiently and safely.

Disparities in Decompressive Cranial Surgery Utilization in Severe Traumatic Brain Injury Patients without a Primary Extra-Axial Hematoma: A U.S. Nationwide Study.

OBJECTIVE: Decompressive craniectomy is recommended to reduce mortality in severe traumatic brain injury (TBI). Disparities exist in TBI treatment outcomes; however, data on disparities pertaining to decompressive craniectomy utilization is lacking. We investigated these disparities, focusing on race, insurance, sex, and age. METHODS: Hospitalizations (2004-2014) were retrospectively extracted from the Nationwide Inpatient Sample. The criteria included are as follows: age ≥18 years and indicators of severe TBI diagnosis. Poor outcomes were defined as discharge to institutional care and death. Multivariable logistic regression models were used to assess the effects of race, insurance, age, and sex, on craniectomy utilization and outcomes. RESULTS: Of 349,164 hospitalized patients, 6.8% (n = 23,743) underwent craniectomy. White (odds ratio [OR] = 0.50, 95% confidence interval [CI] = 0.44-0.57; P < 0.001) and Black (OR = 0.45, 95% CI = 0.32-0.64; P = 0.003) Medicare beneficiaries were less likely to undergo craniectomy. Medicare (P < 0.0001) and Medicaid beneficiaries (P < 0.0001) of all race categories had poorer outcomes than privately insured White patients. Black (OR = 1.2, 95% CI = 1.08-2.34; P = 0.001) patients with private insurance and Black (OR = 1.39, 95% CI = 1.22-1.58; P < 0.0001) Medicaid beneficiaries had poorer outcomes than privately insured White patients (P < 0.0001). Older patients (OR = 0.74, 95%, CI = 0.71-0.76; P < 0.001) were less likely to undergo craniectomy and were more likely to have poorer outcomes. Females (OR = 0.82, 95% CI = 0.76-0.88; P < 0.001) were less likely to undergo craniectomy. CONCLUSIONS: There are disparities in race, insurance status, sex, and age in craniectomy utilization and outcome. This data highlights the necessity to appropriately address these disparities, especially race and sex, and actively incorporate these factors in clinical trial design and enrollment.

Curing SMA: Are we there yet?

Loss or deletion of survival motor neuron 1 gene (SMN1) is causative for a severe and devastating neuromuscular disease, Spinal Muscular Atrophy (SMA). SMN1 produces SMN, a ubiquitously expressed protein, that is essential for the development and survival of motor neurons. Major advances and developments in SMA therapeutics are shifting the natural history of the disease. With three relatively new available therapies, nusinersen (Spinraza), onasemnogene abeparvovec (Zolgensma), and risdiplam (Evrysdi), patients survive longer and have improved outcomes. However, patients and families continue to face many challenges associated with use of these therapies, including poor treatment response and a variability in the benefits to those that do respond, suggesting that the quest for the SMA cure is not over. In this review, we discuss the current therapies, their limitations, and highlight necessary gaps that need to be addressed to guarantee the best outcomes for SMA patients.

The All-Ireland Guidelines for the diagnosis, assessment and management of lymphoedema.

The last decade has produced a plethora of lymphoedema-based research. As such, a new All-Ireland Guideline for lymphoedema diagnosis, assessment and management was required to replace the 2008 CREST Guideline. A research team was commissioned to work with healthcare staff and service users following international research standards practice. An evidence-based clinical practice guideline was developed to aid clinicians in the diagnosis, assessment, and management of lymphoedema. Recommendations were formulated based on the evidence available to answer each clinical question and were assigned a grade based on the strength of the evidence. In the absence of sufficient evidence and in an effort to maximise clinical applicability, recommendations were also based on expert opinion, which was gathered via guideline member consensus. The recommendations from the guideline, which aim to provide healthcare professionals with clear, evidence-based guidance on the diagnosis, assessment and management of patients with all types of lymphoedema, should be communicated at all levels regarding responsibility for implementation in clinical care and service development. Audit should be a core component of the implementation. A budget impact analysis should be completed to determine additional costs required to fully implement the guideline.

Haemophilus influenzae type f in the post-Haemophilus influenzae type b vaccination era: a systematic review.

Since the introduction of Haemophilus influenzae (Hi) serotype b (Hib) vaccination, reports of increasing incidence rates of non-Hib serotypes have emerged. A systematic review was performed to investigate whether the Hi serotype f (Hif) incidence rate has increased globally and to describe its associated disease burden. In the post-Hib vaccine era, evidence shows that the incidence rate of Hif infection is increasing worldwide. In total 94 studies including 2 701 patients reported Hif infections. The estimated pooled incidence rate of Hif infection was 0.15/100 000 population per year (range: 0.05-0.40/100 000), with a median case fatality ratio of 14.3 %. Invasive infections most frequently presented as pneumonia (45 %), septicaemia (34 %) and meningitis (20 %). Of 191 Hif isolates, 87 % were ampicillin-susceptible. Multi-locus sequence typing revealed that Hif were relatively clonal, with the majority belonging to clonal complex 124. Hif causes invasive infections of significant variance in both severity and presentation. Globally, the Hif population shows little genetic variability and currently appears to possess low resistance to antimicrobials.

Central and peripheral delivered AAV9-SMN are both efficient but target different pathomechanisms in a mouse model of spinal muscular atrophy.

Spinal muscular atrophy (SMA) is a neuromuscular disease caused by loss of the SMN1 gene and low SMN protein levels. Although lower motor neurons are a primary target, there is evidence that peripheral organ defects contribute to SMA. Current SMA gene therapy and clinical trials use a single intravenous bolus of the blood-brain-barrier penetrant scAAV9-cba-SMN by either systemic or central nervous system (CNS) delivery, resulting in impressive amelioration of the clinical phenotype but not a complete cure. The impact of scAAV9-cba-SMN treatment regimens on the CNS as well as on specific peripheral organs is yet to be described in a comparative manner. Therefore, we injected SMA mice with scAAV9-cba-SMN either intravenously (IV) for peripheral SMN restoration or intracerebroventricularly (ICV) for CNS-focused SMN restoration. In our system, ICV injections increased SMN in peripheral organs and the CNS while IV administration increased SMN in peripheral tissues only, largely omitting the CNS. Both treatments rescued several peripheral phenotypes while only ICV injections were neuroprotective. Surprisingly, both delivery routes resulted in a robust rescue effect on survival, weight, and motor function, which in IV-treated mice relied on peripheral SMN restoration but not on targeting the motor neurons. This demonstrates the independent contribution of peripheral organs to SMA pathology and suggests that treatments should not be restricted to motor neurons.

Venous Thromboembolism Risk and Outcomes Following Decompressive Craniectomy in Severe Traumatic Brain Injury: An Analysis of the Nationwide Inpatient Sample Database.

OBJECTIVE: Traumatic brain injury (TBI) is a risk factor for venous thromboembolism (VTE). The risk of VTE after decompressive craniectomy (DC) and its effects on the outcomes are unknown. We assessed the incidence of VTE, associated risk factors, and effects on the outcomes. METHODS: Using the National Inpatient Sample database, the hospitalizations of patients aged ≥18 years with a severe TBI diagnosis from 2004 to 2014 were extracted. The outcome was discharge status without mortality. Multivariable logistic and linear regressions were used. RESULTS: Of the 349,165 TBI hospitalizations, 23,813 (6.82%) had undergone DC and 14,175 (4.06%) had developed VTE. The VTE incidence was higher after DC compared with no DC (6.14% vs. 3.91%; P < 0.0001). DC (odds ratio [OR], 1.29; P < 0.005) was an independent predictor for the development of VTE. Age (OR, 1.26; P < 0.005), chronic lung disease (OR, 1.58; P < 0.05), electrolyte imbalance (OR, 1.43; P < 0.05), liver disease (OR, 0.10; P < 0.05), urinary tract infection (OR, 1.56; P < 0.05), pneumonia (OR, 2.03; P < 0.0001), and sepsis (OR, 1.57; P < 0.05) were significantly associated with the development of VTE. Obesity (OR, 2.09; P > 0.05) and spine injury (OR, 2.03; P > 0.05) showed a trend toward significance. VTE was associated with worse discharge outcomes (OR, 1.40; P < 0.05), longer lengths of stay (OR, 1.01; P < 0.00001), and higher costs (P < 0.0001). CONCLUSIONS: Our study showed an independent association between DC and an increased risk of VTE for patients with severe TBI. The development of VTE after DC increased the proportion of poor outcomes, prolonged the length of stay, and increased the hospitalization costs. Older patients with obesity, an electrolyte imbalance, chronic lung disease, spine injury, and infections were at a greater risk of VTE after DC. These risk factors could help in considering VTE prophylaxis for these patients.

Costing pressure ulcer care in an Irish acute care setting: a feasibility study.

OBJECTIVE: To test the feasibility of using a standardised data collection tool to estimate the cost of stage 2-4 pressure ulcer (PU) care within an acute care setting. METHOD: Data on resource use and cost were obtained through a retrospective survey of nursing and medical notes collecting cost data for individual patients who received care for stage 2-4 PUs. RESULTS: Data for 20 patients (12 male/8 female) were analysed. The average patient age was 69 years (range: 37-95 years). Of this sample, seven patients had hospital-acquired PUs (HAPUs) and 14 patients had community-acquired PUs (CAPU) (one patient had both-in different anatomical areas). Over half of the total sample (55%; n=11) had a stage 2 PU. The average length of stay was 31.8 days (range: 5-119 days). Most of the patients (70%; n=14) had a CAPU. The average cost per patient with PU care was €878 (range: €39-2393). The mean cost for patients with a HAPU was €866 (SD: €1313) versus €911 (SD: €567) for patients with a CAPU. The majority of the cost related to equipment and staff time for treatment. CONCLUSION: Overall, the application of the standardised data collection tool to obtain cost data from retrospective inspection of nursing and medical notes is feasible. The cost of PU care in this sample was high, indicating that these wounds may impose a substantial burden on health systems. The costs varied greatly between patients in the sample, reflecting the complexity of PU care. Furthermore, given that costs increased with the higher PU stages, there is a potential to reduce costs by preventing the development of higher stage PUs. Larger-scale studies are required to understand the cost variation and full economic impact of PU care. DECLARATION OF INTEREST: The authors have no conflicts of interest.

A clinical investigation into the ability of subjects with lung disease to provide breath specimens using the EvidenzerIRL evidential breath analyser in alcohol intoxicant driving in criminal justice evidence.

The EvidenzerIRL instrument has been in use as an evidential breath analyser in the application of drink driving laws in the Republic of Ireland since 2011. The result of the analysis is used as evidence in prosecutions before the Courts in per se offences of driving under the influence of alcohol as distinct from screening results at the roadside. This study aims to assist doctors, lawyers and judges in assessing drivers' failure to provide valid evidential breath specimens. Since the introduction of the EvidenzerIRL, approximately 10% of evidential breath tests annually result in failure or refusal to provide a successful breath specimen, this is an offence under Irish road traffic laws. The presence of lung disease has been given as a reason for the driver failing to provide evidential breath specimens. The aim of this study is to assess the ability of subjects with lung disease to provide breath specimens using the EvidenzerIRL. Pulmonary function tests (PFT) were carried out on volunteers from outpatients of the pulmonary laboratory in St Vincent's University Hospital, Dublin (n = 58) and a control group with no underlying lung disease (n = 19). After the PFTs all volunteers were asked to provide breath specimens using the EvidenzerIRL. Fourteen (24%) out of 58 lung disease volunteers failed to provide a breath specimen, no one from the control group was unsuccessful. Thirteen females and one male volunteer could not successfully provide. Female volunteers were more likely to fail to provide than male volunteers. A significant difference was found between the median age of successful (62.2 years) and unsuccessful (69.2 years) lung disease volunteers. Only one PFT, percentage predicted of Forced Expiratory Volume in 1 second (FEV1), had a significant difference between the mean of successful (86.6%) and unsuccessful (66.5%) lung disease volunteers. A subject with lung disease was more likely to be successful than unsuccessful. Drivers' effort and operators' guidance through the process were found to be crucial parts to a successful outcome.

The Use of Targeted Monoclonal Antibodies in the Treatment of ABPA-A Case Series.

Allergic bronchopulmonary aspergillosis (ABPA) is a pulmonary disorder occurring in response to Aspergillus fumigatus that can complicate the course of asthma and cystic fibrosis. Here we present a case of acute ABPA without central bronchiectasis, a case of chronic active ABPA with central bronchiectasis, and a case of severe relapsing ABPA with central bronchiectasis. All three were initially treated with corticosteroids and antifungal agents but had an incomplete response. These patients were then treated with anti-IgE therapy with omalizumab before being switched to the anti-IL5R agent benralizumab. They responded well to both agents. These case reports highlight the potential role of omalizumab and benralizumab in the treatment of ABPA, but further studies are required to evaluate the effectiveness of these medications. Longer follow-up periods and objective measurements of the impact of treatment are necessary.

Sepsis in surgical inpatients: under-recognised but with significant consequences.

BACKGROUND: The true incidence of sepsis in surgical cohorts in Ireland remains unclear. According to inpatient audits, patients in surgical diagnostic groups (DRG) who developed sepsis had a longer length of stay and higher mortality rate compared with medical DRG patients who developed sepsis. AIMS: We investigated sepsis incidence on a general surgical ward to identify risk factors and strategies to improve management. METHODS: Demographics, admission and discharge details, infection risk factors, infection, and sepsis were studied prospectively on a surgical ward in July 2018. RESULTS: The mean age of 164 patients was 60.5 years (range 18-93 years), 107 (65.2%) were admitted electively, 16 (9.8%) were colonised with a multidrug-resistant organism (MDRO), and 30 (18.3%) were classified as frail on admission. Twelve (7.3%) developed sepsis (ward sepsis rate 118.2/10,000 bed days used). 'Sepsis' was documented in six cases and the national sepsis screening form used in four patients. Patients with sepsis were three times as likely to be MDRO-colonised (OR 3.56; 95% CI = 0.86-14.82; p = 0.065) or frail (OR 3.63; 95% CI = 1.07-12.35; p = 0.03), four times as likely to be an inpatient at the end of the study (OR 4.22, 96% CI 1.23-14.49; p = 0.01), and three times as likely to be readmitted (OR 3.46, 95% CI 1.02-11.76; p = 0.03). CONCLUSION: Sepsis was under-documented, and barriers exist with use of the national sepsis screening form. Frailty, which is a sepsis risk factor, should be assessed pre-operatively to maximise prevention.

Applying rigorous eligibility criteria to studies evaluating prognostic utility of serum biomarkers in pulmonary embolism: A systematic review and meta-analysis.

PURPOSE: To evaluate the value of biomarkers to prognosticate outcomes in patients with pulmonary embolism among studies of sound methodical quality. METHODS: Ovid MEDLINE, Embase, CENTRAL, and non-indexed citations were searched from inception to March 2019. Biomarkers of interest included troponin I (TnI), troponin T (TnT), high-sensitive TnT (HS-TnT), brain natriuretic peptide (BNP), N-terminal pro-BNP (NT-proBNP), heart fatty acid binding protein (H-FABP), and D-dimer (DD). Included studies utilized key features of the Reporting Recommendations for Tumour Marker Prognostic Studies (REMARK) checklist and satisfied requirements of the Quality in Prognosis Studies (QUIPS) tool. The primary outcome was 30-day all-cause mortality (ACM). Secondary outcomes included PE-related mortality, or complicated clinical course (CCC). Pooled relative risk ratios (RR) were calculated using inverse-variance-weighted random-effects method. RESULTS: Seventeen studies were analyzed. TnT ≥ 0.1 ng/mL and HS-TnT ≥ 14 pg/mL were associated with an increased 30-day ACM with RRs of 6.24 (95% CI, 1.86-20.96, I2 = 35%) and 6.81 (95% CI, 2.46-18.88, I2 = 0%), respectively. In the short-term (≤30 days): (1) TnI can prognosticate PE-related mortality; (2) both TnT and HS-TnT can prognosticate a CCC; (3) H-FABP can prognosticate a CCC; and (4) NT-proBNP can prognosticate a CCC. In the long-term (>30 days): (1) HS-TnT can prognosticate ACM; and (2) NT-proBNP can prognosticate ACM and PE-related mortality. CONCLUSIONS: Several methodically sound studies allow for data pooling, and suggest that TnT, HS-TnT, TnI, NT-proBNP and H-FABP have prognostic value in patients with PE but confidence intervals are wide and relatively few patients constitute the analyses. The value of such markers on influencing clinical management remains to be determined. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42019129889.

A clinical investigation into the ability of subjects with a lung disease to provide breath specimens using the Dräger 6510.

In the enforcement of drink driving laws failing to provide a breath specimen for alcohol analysis at the roadside when requested by a Police Officer is an offence in many countries. Some drivers claim that a lung disease prevented their ability to be successful. This study aims to investigate the relationship between the presence of a lung disease and the ability to provide a successful breath specimen using the Dräger 6510 screening device. Sixty participants with lung disease and nineteen control participants underwent pulmonary function tests and were then tested with a Dräger 6510 screening device. Only one participant was unsuccessful using the Dräger 6510, this participant suffered from interstitial lung disease. The pulmonary function test results did not indicate if someone would be successful or how many attempts would be needed to be successful. The presence of a lung disease did not indicate if a driver would be unsuccessful however all participants were free from infection and the participants with a lung disease were stable at the time of testing. Correct instruction, subject cooperation and the technique used by the driver to provide a breath specimen were found to be important factors in the success of a breath test.

Motor transmission defects with sex differences in a new mouse model of mild spinal muscular atrophy.

BACKGROUND: Mouse models of mild spinal muscular atrophy (SMA) have been extremely challenging to generate. This paucity of model systems has limited our understanding of pathophysiological events in milder forms of the disease and of the effect of SMN depletion during aging. METHODS: A mild mouse model of SMA, termed Smn2B/-;SMN2+/-, was generated by crossing Smn-/-;SMN2 and Smn2B/2B mice. This new model was characterized using behavioral testing, histology, western blot, muscle-nerve electrophysiology as well as ultrasonography to study classical SMA features and extra-neuronal involvement. FINDINGS: Smn2B/-;SMN2+/- mice have normal survival, mild but sustained motor weakness, denervation and neuronal/neuromuscular junction (NMJ) transmission defects, and neurogenic muscle atrophy that are more prominent in male mice. Increased centrally located nuclei, intrinsic contractile and relaxation muscle defects were also identified in both female and male mice, with some male predominance. There was an absence of extra-neuronal pathology. INTERPRETATION: The Smn2B/-;SMN2+/- mouse provides a model of mild SMA, displaying some hallmark features including reduced weight, sustained motor weakness, electrophysiological transmission deficit, NMJ defects, and muscle atrophy. Early and prominent increase central nucleation and intrinsic electrophysiological deficits demonstrate the potential role played by muscle in SMA disease. The use of this model will allow for the understanding of the most susceptible pathogenic molecular changes in motor neurons and muscles, investigation of the effects of SMN depletion in aging, sex differences and most importantly will provide guidance for the currently aging SMA patients treated with the recently approved genetic therapies. FUNDING: This work was supported by Cure SMA/Families of SMA Canada (grant numbers KOT-1819 and KOT-2021); Muscular Dystrophy Association (USA) (grant number 575466); and Canadian Institutes of Health Research (CIHR) (grant number PJT-156379).