Medical management and surgery versus medical management alone for symptomatic cerebral cavernous malformation (CARE): a feasibility study and randomised, open, pragmatic, pilot phase trial

BACKGROUND

The highest priority uncertainty for people with symptomatic cerebral cavernous malformation is whether to have medical management and surgery or medical management alone. We conducted a pilot phase randomised controlled trial to assess the feasibility of addressing this uncertainty in a definitive trial.

METHODS

The CARE pilot trial was a prospective, randomised, open-label, assessor-blinded, parallel-group trial at neuroscience centres in the UK and Ireland. We aimed to recruit 60 people of any age, sex, and ethnicity who had mental capacity, were resident in the UK or Ireland, and had a symptomatic cerebral cavernous malformation. Computerised, web-based randomisation assigned participants (1:1) to medical management and surgery (neurosurgical resection or stereotactic radiosurgery) or medical management alone, stratified by the neurosurgeon's and participant's consensus about the intended type of surgery before randomisation. Assignment was open to investigators, participants, and carers, but not clinical outcome event adjudicators. Feasibility outcomes included site engagement, recruitment, choice of surgical management, retention, adherence, data quality, clinical outcome event rate, and protocol implementation. The primary clinical outcome was symptomatic intracranial haemorrhage or new persistent or progressive non-haemorrhagic focal neurological deficit due to cerebral cavernous malformation or surgery during at least 6 months of follow-up. We analysed data from all randomly assigned participants according to assigned management. This trial is registered with ISRCTN (ISRCTN41647111) and has been completed.

FINDINGS

Between Sept 27, 2021, and April 28, 2023, 28 (70%) of 40 sites took part, at which investigators screened 511 patients, of whom 322 (63%) were eligible, 202 were approached for recruitment, and 96 had collective uncertainty with their neurosurgeon about whether to have surgery for a symptomatic cerebral cavernous malformation. 72 (22%) of 322 eligible patients were randomly assigned (mean recruitment rate 0·2 [SD 0·25] participants per site per month) at a median of 287 (IQR 67-591) days since the most recent symptomatic presentation. Participants' median age was 50·6 (IQR 38·6-59·2) years, 68 (94%) of 72 participants were adults, 41 (57%) were female, 66 (92%) were White, 56 (78%) had a previous intracranial haemorrhage, and 28 (39%) had a previous epileptic seizure. The intended type of surgery before randomisation was neurosurgical resection for 19 (26%) of 72, stereotactic radiosurgery for 44 (61%), and no preference for nine (13%). Baseline clinical and imaging data were complete for all participants. 36 participants were randomly assigned to medical management and surgery (12 to neurosurgical resection and 24 to stereotactic radiosurgery) and 36 to medical management alone. Three (4%) of 72 participants withdrew, one was lost to follow-up, and one declined face-to-face follow-up, leaving 67 (93%) retained at 6-months' clinical follow-up. 61 (91%) of 67 participants with follow-up adhered to the assigned management strategy. The primary clinical outcome occurred in two (6%) of 33 participants randomly assigned to medical management and surgery (8·0%, 95% CI 2·0-32·1 per year) and in two (6%) of 34 participants randomly assigned to medical management alone (7·5%, 1·9-30·1 per year). Investigators reported no deaths, no serious adverse events, one protocol violation, and 61 protocol deviations.

INTERPRETATION

This pilot phase trial exceeded its recruitment target, but a definitive trial will require extensive international engagement.

FUNDING

National Institute for Health and Care Research.

Risks of second primary cancers among 584,965 female and male breast cancer survivors in England: a 25-year retrospective cohort study

Background

Second primary cancers (SPCs) after breast cancer (BC) present an increasing public health burden, with little existing research on socio-demographic, tumour, and treatment effects. We addressed this in the largest BC survivor cohort to date, using a novel linkage of National Disease Registration Service datasets.

Methods

The cohort included 581,403 female and 3562 male BC survivors diagnosed between 1995 and 2019. We estimated standardized incidence ratios (SIRs) for combined and site-specific SPCs using incidences for England, overall and by age at BC and socioeconomic status. We estimated incidences and Kaplan-Meier cumulative risks stratified by age at BC, and assessed risk variation by socio-demographic, tumour, and treatment characteristics using Cox regression.

Findings

Both genders were at elevated contralateral breast (SIR: 2.02 (95% CI: 1.99-2.06) females; 55.4 (35.5-82.4) males) and non-breast (1.10 (1.09-1.11) females, 1.10 (1.00-1.20) males) SPC risks. Non-breast SPC risks were higher for females younger at BC diagnosis (SIR: 1.34 (1.31-1.38) <50 y, 1.07 (1.06-1.09) ≥50 y) and more socioeconomically deprived (SIR: 1.00 (0.98-1.02) least deprived quintile, 1.34 (1.30-1.37) most).

Interpretation

Enhanced SPC surveillance may benefit BC survivors, although specific recommendations require more detailed multifactorial risk and cost-benefit analyses. The associations between deprivation and SPC risks could provide clinical management insights.

Funding

CRUK Catalyst Award CanGene-CanVar (C61296/A27223). Cancer Research UK grant: PPRPGM-Nov 20∖100,002. This work was supported by core funding from the NIHR Cambridge Biomedical Research Centre (NIHR203312)]. The views expressed are those of the author(s) and not necessarily those of the NIHR or the Department of Health and Social Care.

Feasibility of comparing medical management and surgery (with neurosurgery or stereotactic radiosurgery) with medical management alone in people with symptomatic brain cavernoma - protocol for the Cavernomas: A Randomised Effectiveness (CARE) pilot trial

INTRODUCTION

The top research priority for cavernoma, identified by a James Lind Alliance Priority setting partnership was 'Does treatment (with neurosurgery or stereotactic radiosurgery) or no treatment improve outcome for people diagnosed with a cavernoma?' This pilot randomised controlled trial (RCT) aims to determine the feasibility of answering this question in a main phase RCT.

METHODS AND ANALYSIS

We will perform a pilot phase, parallel group, pragmatic RCT involving approximately 60 children or adults with mental capacity, resident in the UK or Ireland, with an unresected symptomatic brain cavernoma. Participants will be randomised by web-based randomisation 1:1 to treatment with medical management and with surgery (neurosurgery or stereotactic radiosurgery) versus medical management alone, stratified by prerandomisation preference for type of surgery. In addition to 13 feasibility outcomes, the primary clinical outcome is symptomatic intracranial haemorrhage or new persistent/progressive focal neurological deficit measured at 6 monthly intervals. An integrated QuinteT Recruitment Intervention (QRI) evaluates screening logs, audio recordings of recruitment discussions, and interviews with recruiters and patients/parents/carers to identify and address barriers to participation. A Patient Advisory Group has codesigned the study and will oversee its progress.

ETHICS AND DISSEMINATION

This study was approved by the Yorkshire and The Humber-Leeds East Research Ethics Committee (21/YH/0046). We will submit manuscripts to peer-reviewed journals, describing the findings of the QRI and the Cavernomas: A Randomised Evaluation (CARE) pilot trial. We will present at national specialty meetings. We will disseminate a plain English summary of the findings of the CARE pilot trial to participants and public audiences with input from, and acknowledgement of, the Patient Advisory Group.

TRIAL REGISTRATION NUMBER

ISRCTN41647111.

Primary retroperitoneal sarcoma: A comparison of survival outcomes in specialist and non-specialist sarcoma centres

BACKGROUND

Consensus guidelines outline that patients with primary retroperitoneal sarcoma (RPS) should be managed within specialist sarcoma centres (SSC). There is, however, a paucity of population-based data detailing incidence and outcomes in these patients. Hence, we aimed to evaluate patterns of care among RPS patients in England and compare outcomes for those undergoing surgery in high-volume specialist sarcoma centres (HV-SSC), low-volume SSC (LV-SSC), and non-SSC (N-SSC).

METHODS

Data on patients diagnosed with primary RPS between 2013 and 2018 were extracted from NHS Digital's National Cancer Registration and Analysis Service using the national cancer registration dataset. Diagnostic pathways, treatment, and survival outcomes were compared between HV-SSC, LV-SSC, and N-SSC. Uni- and multivariate analyses were calculated.

RESULTS

Of 1878 patients diagnosed with RPS, 1120 (60%) underwent surgery within 12 months of diagnosis, with 847 (76%) operated on at SSC; of these, 432 patients (51%) were operated on in HV-SSC, and 415 (49%) in LV-SSC. One- and 5-year estimated overall survival (OS) rates for patients undergoing surgery in N-SSC were 70.6% (95% confidence interval [CI]: 64.8-75.7) and 42.0% (CI: 35.9-47.9), compared to 85.0% (CI: 81.1-88.1) and 51.7% (CI: 46.6-56.6) in LV-SSC (p < 0.01), and 87.4% (CI: 83.9-90.2) and 62.8% (CI: 57.9-67.4) in HV-SSC, (p < 0.01). After adjusting for patient- and treatment-related factors, patients treated in HV-SSC were found to have significantly longer OS than those treated at LV-SSC, with an adjusted hazard ratio of 0.78 (CI: 0.62-0.96, p < 0.05).

CONCLUSION

Patients with RPS undergoing surgery in HV-SSC have significantly better survival outcomes than those treated in N-SSC and L-SSC.

Incidence and survival of soft tissue sarcoma in England between 2013 and 2017, an analysis from the National Cancer Registration and Analysis Service

There is a paucity of population-based data detailing the incidence and survival of patients with soft tissue sarcoma (STS), in part due to the heterogeneity of disease and changes to classification. Here, the incidence and survival of all STS subtypes registered in England between 2013 and 2017 were analysed using cancer registry data held by the National Cancer Registration and Analysis Service. Age-standardised incidence rates were calculated per 1 000 000 using the 2013 European Standard Population. Net survival was computed using Brenner's alternative method, with the Ederer II estimator. Age-specific overall survival was assessed using Kaplan-Meier. The influence of age, sex, socioeconomic deprivation and diagnostic routes on survival was assessed using Cox proportional hazards modelling. In total, 19 717 patients were diagnosed with STS, an average of 3943 patients per year and representing approximately 0.8% of malignancies. The most common histological diagnoses were Gastrointestinal Stromal Tumours (GIST), leiomyosarcoma and undifferentiated sarcoma, accounting for 20.2%, 13.3% and 12.7% of all sarcomas, respectively. Five-year net survival for all malignant STS was 65.0%; and was lowest for patients with vascular tumours at 39%. Patients from most deprived cohorts had 23% greater chance of dying within 5 years than patients in least deprived areas. This population-based study has allowed us for the first time to define the incidence and survival rates of prevalent STS subtypes in England such as GIST, liposarcoma and leiomyosarcoma, as well as rare entities and groups with inferior outcome. This data is invaluable for service provision, benchmarking and addressing inequality.

Abstract 988: Long-term health outcomes of bilateral salpingo-oophorectomy in women with personal history of breast cancer

Introduction: Breast cancer is the most common cancer in women. Women with personal history of breast cancer are at increased risk of second primary cancers including ovarian cancer. Bilateral salpingo-oophorectomy (BSO) is a well-established option for ovarian cancer risk reduction. However, the benefit of ovarian cancer risk reduction should be balanced against the health sequelae caused by the premature estrogen loss. We examined the associations between BSO after breast cancer diagnosis and long-term health outcomes, using large-scale linked electronic health records.

Methods: We selected women diagnosed with invasive breast cancer before the age of 75 between 1995 and 2019 using data from the National Cancer Registration Dataset (NCRD), which describes all cancers registered in England. These women were linked to the Hospital Episode Statistics (HES) Admitted Patient Care (APC) dataset to identify the delivery of BSO, while the use of hormonal replacement therapy (HRT) was identified from the community dispensed prescriptions dataset. Long-term outcomes (e.g., ischemic heart disease) were selected from HES, and the NCRD provided data on second cancer diagnosis and all-cause mortality. Multiple imputation was used to impute missing data on stage, grade, hormonal receptor status and ethnicity. Women were followed from the date of breast cancer diagnosis to development of an outcome of interest or censoring or end of data collection. Multivariable Cox regression was used to examine the associations, with BSO modeled as a time-dependent covariate. The analysis was stratified by patient age at BSO (&lt;55 and ≥55 years).

Results: The study included 566,731 women, with median follow up time 8.40 (IQR: 4.4-14.5) years. Of those, 23,881 women had BSO after their breast cancer diagnosis. BSO before the age of 55 was not associated with all-cause mortality (hazard ratio (HR):1.03, 95%CI:0.98-1.08), while BSO after the age of 55 was associated with a small reduction in the risk of all-cause mortality (HR:0.93, 95%CI:0.89-0.99). BSO before and after the age of 55 was associated with increased risk of ischemic heart disease with HRs of 1.23(95%CI:1.07-1.41) and 1.13(95%CI:1.02-1.25), respectively. There was no association between BSO and cerebrovascular events (HR:0.97, 95%CI:0.82-1.15, for BSO under age 55, HR:0.96, 95%CI:0.87-1.07, for BSO after age 55). Ongoing analyses are investigating the associations stratified by the severity of cardiovascular outcome (fatal/non-fatal) and the use of HRT, and the associations with second cancers and neuropsychiatric outcomes.

Conclusion: BSO after 55 does not appear to be associated with detrimental health effects in women diagnosed with breast cancer. Further examination of the associations between BSO and other long-term health outcomes and the influence of HRT in younger women is needed.

Citation Format: Hend Hassan, Tameera Rahman, Andrew Bacon, Craig Knott, Isaac Allen, Catherine Huntley, Lucy Loong, Yvonne Walburga, Katrina Lavelle, Eva Morris, Steven Hardy, Bethany Torr, Diana M Eccles, Clare Turnbull, Marc Tischkowitz, Paul Pharoah, Antonis C. Antoniou. Long-term health outcomes of bilateral salpingo-oophorectomy in women with personal history of breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 988.

Abstract 3057: Second primary cancer risks for female and male breast cancer survivors

Background: Second primary cancer (SPC) incidence is rising among breast cancer (BC) survivors, but these risks remain unclear. We estimated SPC risks for male and female BC survivors using large-scale electronic health record data from a linkage of National Cancer Registration and Analysis Service data and Hospital Episode Statistics surgical records in England.

Material and Methods: We used a retrospective cohort study design comprising 763,578 female and 4,795 male BC survivors first diagnosed with BC between 1995-2018. We calculated overall and site-specific SPC standardized incidence ratios (SIRs) by comparing observed and expected SPC counts for 19 cancer sites. Study participants were followed from one year after the first BC diagnosis until either a SPC diagnosis (excluding ipsilateral breast and non-melanoma skin cancers), death, migration, relevant surgical procedures, or the end of 2019. Expected SPC counts were calculated using year-, age- and sex-specific cancer incidence rates in the general English population. We stratified the SIRs by age group, sex, and cancer site. We estimated Kaplan-Meier absolute risks of site-specific SPCs and assessed the influence of age at first BC diagnosis using Cox proportional hazards models.

Results: There were 68,550 and 720 incident SPCs among female and male BC survivors, respectively. There was a significant increased risk of all SPCs combined for female BC survivors (SIR: 1.19, 95%CI: 1.18-1.20). There were significant increased risks for SPC at all sites combined, all non-breast sites combined, and at 12 further specific sites for females and at 2 specific sites for males. Among females, the increase was greatest for contralateral breast (SIR: 1.82, 95%CI: 1.79-1.85) and uterine cancers (SIR: 1.80, 95%CI: 1.76-1.85). The risk at all sites combined was higher for women first diagnosed with BC before age 50 (SIR: 1.89, 95%CI: 1.85-1.92) compared to women diagnosed with BC at age 50 or over (SIR: 1.11, 95%CI: 1.10-1.12). The largest associations were observed for contralateral breast (SIR: 3.19, 95%CI: 3.11-3.29) and uterine (SIR: 1.77, 95%CI: 1.73-1.82) SPCs in the younger and older age groups, respectively. Increasing age at first female BC diagnosis was associated with decreasing CBC absolute risks, but significantly increased absolute risks of all other SPCs. Male BC survivors were at increased risk of contralateral breast (SIR: 42.39, 95%CI: 28.39-60.89) and prostate (SIR: 1.29, 95%CI: 1.13-1.46) SPCs.

Conclusions: This is the largest study to date to assess SPC risks following BC in either men or women. SPC risks were significantly increased, both in combination and at specific sites. These findings could help guide clinical management, such as screening recommendations, for BC survivors. Further analysis is underway to investigate the effects of chemotherapy, radiotherapy, hormonal therapy, comorbidities, or germline BC susceptibility.

Citation Format: Isaac Allen, Tameera Rahman, Andrew Bacon, Craig Knott, Sophie Jose, Sally Vernon, Hend Hassan, Catherine Huntley, Lucy Loong, Yvonne Walburga, Katrina Lavelle, Eva Morris, Steven Hardy, Beth Torr, Diana Eccles, Clare Turnbull, Marc Tischkowitz, Paul Pharoah, Antonis C. Antoniou. Second primary cancer risks for female and male breast cancer survivors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3057.

A survey of the radiological follow-up of unruptured intracranial aneurysms in the United Kingdom

OBJECTIVE

Unruptured intracranial aneurysms (UIA) are common. For many the treatment risks outweigh their risk of subarachnoid haemorrhage and patients undergo surveillance imaging. There is little data to inform if and how to monitor UIAs resulting in widely varying practices. This study aimed to determine the current practice of unruptured UIA surveillance in the United Kingdom.

METHODS

A questionnaire was designed to address the themes of surveillance protocols for UIA including when surveillance is initiated, how frequently it is performed, and when it is terminated. Additionally, how aneurysm growth is managed and how clinically meaningful growth is defined were explored. The questionnaire was distributed to members of the British Neurovascular Group using probability-based cluster and non-probability purposive sampling methods.

RESULTS

Responses were received from 30 of the 30 (100.0%) adult neurosurgical units in the United Kingdom of which 27 (90.0%) routinely perform surveillance for aneurysm growth. Only four units had a unit policy. The mean patient age up to which a unit would initiate follow-up of a low-risk UIA was 65.4 ± 9.0 years. The time points at which imaging is performed varied widely. There was an even split between whether units use a fixed duration of follow-up or an age threshold for terminating surveillance. Forty percent of units will follow-up patients more than 5 years from diagnosis. The magnitude in the change in size that was felt to constitute growth ranged from 1 to 3mm. No units routinely used vessel wall imaging although 27 had access to 3T MRI capable of performing it.

CONCLUSIONS

There is marked heterogeneity in surveillance practices between units in the United Kingdom. This study will help units better understand their practice relative to their peers and provide a framework forplanning further research on aneurysm growth.

Risk of Aneurysm Rupture (ROAR) study: protocol for a long-term, longitudinal, UK multicentre study of unruptured intracranial aneurysms

INTRODUCTION

Unruptured intracranial aneurysms (UIA) are common in the adult population, but only a relatively small proportion will rupture. It is therefore essential to have accurate estimates of rupture risk to target treatment towards those who stand to benefit and avoid exposing patients to the risks of unnecessary treatment. The best available UIA natural history data are the PHASES study. However, this has never been validated and given the known heterogeneity in the populations, methods and biases of the constituent studies, there is a need to do so. There are also many potential predictors not considered in PHASES that require evaluation, and the estimated rupture risk is largely based on short-term follow-up (mostly 1 year). The aims of this study are to: (1) test the accuracy of PHASES in a UK population, (2) evaluate additional predictors of rupture and (3) assess long-term UIA rupture rates.

METHODS AND ANALYSIS

The Risk of Aneurysm Rupture study is a longitudinal multicentre study that will identify patients with known UIA seen in neurosurgery units. Patients will have baseline demographics and aneurysm characteristics collected by their neurosurgery unit and then a single aggregated national cohort will be linked to databases of hospital admissions and deaths to identify all patients who may have subsequently suffered a subarachnoid haemorrhage. All matched admissions and deaths will be checked against medical records to confirm the diagnosis of aneurysmal subarachnoid haemorrhage. The target sample size is 20 000 patients. The primary outcome will be aneurysm rupture resulting in hospital admission or death. Cox regression models will be built to test each of the study's aims.

ETHICS AND DISSEMINATION

Ethical approval has been given by South Central Hampshire A Research Ethics Committee (21SC0064) and Confidentiality Advisory Group support (21CAG0033) provided under Section 251 of the NHS Act 2006. The results will be disseminated in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

ISRCTN17658526.

Generation of a thermostable, oral Zika vaccine that protects against virus challenge in non-human primates

Here we report the development of a thermally stable, orally administered, candidate Zika vaccine using human serotype 5 adenovirus (AdHu5). We engineered AdHu5 to express the genes for the envelope and NS1 proteins of Zika virus. AdHu5 was formulated using a proprietary platform, OraPro, comprising a mix of sugars and modified amino acids that can overcome elevated temperatures (37 C), and an enteric coated capsule that protects the integrity of the AdHu5 from the acid in the stomach. This enables the delivery AdHu5 to the immune system of the small intestine. We show that oral delivery of AdHu5 elicited antigen-specific serum IgG immune responses in a mouse model and in a non-human primate model. Importantly, these immune responses were able reduce viral counts in mice and to prevent detectable viraemia in the non-human primates on challenge with live Zika virus. This candidate vaccine has significant advantages over many current vaccines that are maintained in a cold or ultra-cold chain and require parenteral administration.

Evidence of Antineutrinos from Distant Reactors Using Pure Water at SNO

The SNO+ Collaboration reports the first evidence of reactor antineutrinos in a Cherenkov detector. The nearest nuclear reactors are located 240 km away in Ontario, Canada. This analysis uses events with energies lower than in any previous analysis with a large water Cherenkov detector. Two analytical methods are used to distinguish reactor antineutrinos from background events in 190 days of data and yield consistent evidence for antineutrinos with a combined significance of 3.5σ.

Radiological follow-up of endovascularly treated intracranial aneurysms: a survey of current practice in the UK and Ireland

PURPOSE

Due to the risk of intracranial aneurysm (IA) recurrence and the potential requirement for re-treatment following endovascular treatment (EVT), radiological follow-up of these aneurysms is necessary. There is little evidence to guide the duration and frequency of this follow-up. The aim of this study was to establish the current practice in neurosurgical units in the UK and Ireland.

METHODS

A survey was designed with input from interventional neuroradiologists and neurosurgeons. Neurovascular consultants in each of the 30 neurosurgical units providing a neurovascular service in the UK and Ireland were contacted and asked to respond to questions regarding the follow-up practice for IA treated with EVT in their department.

RESULTS

Responses were obtained from 28/30 (94%) of departments. There was evidence of wide variations in the duration and frequency of follow-up, with a minimum follow-up duration for ruptured IA that varied from 18 months in 5/28 (18%) units to 5 years in 11/28 (39%) of units. Young patient age, previous subarachnoid haemorrhage and incomplete IA occlusion were cited as factors that would prompt more intensive surveillance, although larger and broad-necked IA were not followed-up more closely in the majority of departments.

CONCLUSIONS

There is a wide variation in the radiological follow-up of IA treated with EVT in the UK and Ireland. Further standardisation of this aspect of patient care is likely to be beneficial, but further evidence on the behaviour of IA following EVT is required in order to inform this process.

Incidence, prevalence and survival in patients with Langerhans cell histiocytosis: A national registry study from England, 2013-2019

This analysis is the largest population-based study to date to provide contemporary and comprehensive epidemiological estimates of all third edition of the International Classification of Diseases for Oncology (ICD-O-3) coded Langerhans cell histiocytosis (LCH) from England. People of all ages were identified from the National Cancer Registration Dataset using ICD-O-3 morphologies 9751-9754 for neoplasms diagnosed in 2013-2019. A total of 658 patients were identified, of whom 324 (49%) were children aged <15 years. The age-standardised incidence rate was 4.46 (95% confidence interval [CI] 3.99-4.98) per million children and 1.06 (95% CI 0.94-1.18) per million adults aged ≥15 years. Prevalence of LCH was 9.95 (95% CI 9.14-10.81) per million persons at the end of 2019. The 1-year overall survival (OS) was 99% (95% CI 97%-100%) for children and 90% (95% CI 87%-93%) for adults. Those aged ≥60 years had poorer OS than those aged <15 years (hazard ratio [HR] 22.12, 95% CI 7.10-68.94; p < 0.001). People in deprived areas had lower OS than those in the least deprived areas (HR 5.36, 95% CI 1.16-24.87; p = 0.03). There will inevitably be other environmental factors and associations yet to be identified, and the continued standardised data collection will allow further evaluation of data over time. This will be increasingly important with developments in LCH management following the large collaborative international trials such as LCH IV.

1671 The Effect Of COVID-19 On the Management and Outcome of Neck of Femur Fractures in A District General Hospital - A Comparative Study

Aim

We wanted to see how the virus has impacted the management and outcome of our neck of femur fracture patients during Spring 2020.

Method

We performed a retrospective study of all neck of femur fracture patients presenting to our hospital from 23rd March 2020 (start of official lockdown in UK) until the end of May 2020 and compared them to patients presenting in the same time period in 2019. We recorded patient demographics, COVID-19 swab results, time to surgery, length of stay, transfers between wards, and 30-day mortality rates.

Results

We identified 75 patients in 2020 compared to 88 in 2019. Average length of stay was 11.4 days compared to 14.3 a year earlier. Mean time to surgery was 32.3 hours compared to 31.6 in 2019. The 30-day mortality increased significantly from 5.7% (5/88) in 2019 to 16% (12/75) in 2020 (p &lt; 0.05) From 73 patients tested for COVID-19, 3 had a positive swab. Of these, 2 died. During their admission, 14 patients were transferred to 3 or more wards; in this group, 30-day mortality was 42.9% (6/14).

Conclusions

There has been a significant increase in 30-day mortality during COVID-19. Despite maintaining our time to surgery and reducing overall length of stay, we saw an increase in mortality, associated with multiple ward transfers rather than a high number of COVID-19 positive swab cases. Changes in pathways and wards configurations led to some patients requiring multiple transfers. This can cause difficulties in coordinated, multidisciplinary care for patients with NOF Fractures.

Dual-Antigen COVID-19 Vaccine Subcutaneous Prime Delivery With Oral Boosts Protects NHP Against SARS-CoV-2 Challenge

We have developed a dual-antigen COVID-19 vaccine incorporating genes for a modified SARS-CoV-2 spike protein (S-Fusion) and the viral nucleocapsid (N) protein with an Enhanced T-cell Stimulation Domain (N-ETSD) to increase the potential for MHC class II responses. The vaccine antigens are delivered by a human adenovirus serotype 5 platform, hAd5 [E1-, E2b-, E3-], previously demonstrated to be effective in the presence of Ad immunity. Vaccination of rhesus macaques with the hAd5 S-Fusion + N-ETSD vaccine by subcutaneous prime injection followed by two oral boosts elicited neutralizing anti-S IgG and T helper cell 1-biased T-cell responses to both S and N that protected the upper and lower respiratory tracts from high titer (1 x 106 TCID50) SARS-CoV-2 challenge. Notably, viral replication was inhibited within 24 hours of challenge in both lung and nasal passages, becoming undetectable within 7 days post-challenge.

National Health Service interventions in England to improve care to Armed Forces veterans

Armed Forces veterans (AFVs) are first and foremost citizens of the UK and are therefore—like all UK residents—entitled to universal healthcare, free at the point of need. This means that AFVs have nearly all their healthcare needs met by the NHS, which provides access to a full range of generic services. However, since 2013 there has been an Armed Forces team that can also support veterans. This review is an assessment of the work of this group over the last eight years. The health needs of AFVs have been investigated and are not significantly different from those of their demographically matched peers. However, due to their demographics, selection at recruitment and their roles, AFVs compared with the general population are more likely to be male, white and old and have fewer pre-existing or hereditary conditions. However, they do suffer from higher rates of musculoskeletal injury, different patterns of mental health illness and have historically been higher users—and abusers—of alcohol and tobacco. In addition to supporting mainstream services used by AFVs, the NHS in England commissions a bespoke range-specific ‘Priority’ NHS services such as those for mental health or for rehabilitation of veterans using prostheses. New interventions are continuing to be developed to improve AFVs’ healthcare and are aligned to the NHS Long Term Plan and the restoration and recovery plans after the COVID-19 pandemic.

Comparison of Navigated versus Fluoroscopic-Guided Pedicle Screw Placement Accuracy and Complication Rate

OBJECTIVES

Accurate placement of the pedicle screw is requisite for any successful spinal instrumentation procedure. Screw insertion can be achieved using free-hand and fluoroscopic- or navigation-guided techniques. We sought to assess the variation in accuracy between fluoroscopic- and navigation-guided techniques, which are both used in Sheffield Teaching Hospitals National Health Service Trust, a tertiary spine referral center.

METHODS

Using a retrospective study design, we assessed all the pedicle screws placed between 2013 and 2018. Radiographic and clinical assessment of all cases was performed.

RESULTS

We studied 176 spinal instrumented cases, with a total of 831 screws implanted, out of which 296 (35.6%) were navigated and 535 (64.4%) were fluoroscopic guided. Pathology treated included spinal stenosis, spondylolisthesis, tumors, and trauma. Suboptimal screw position was identified in 2.03% (n = 6) of the navigation-guided series and 4.11% (n = 22) of the fluoroscopic-guided series with an overall screw misplacement rate of 3.4%. Evaluating surgeons' individual accuracy rates revealed that suboptimal screw placement registered a higher variation for the fluoroscopy-guided technique, and the misplacement rate was higher for surgeons with a lower volume of cases.

CONCLUSIONS

Use of navigation during spinal instrumentation helps lower the rate of screw misplacement for spinal surgeons who are at the beginning of their learning curve or do not frequently perform this kind of procedure. Navigation-guided spinal instrumentation is more accurate compared with fluoroscopic-guided techniques and appears to have a lower complication rate.

Spinal manipulation for the management of cervicogenic headache: A systematic review and meta-analysis

BACKGROUND

Spinal manipulative therapy (SMT) is frequently used to manage cervicogenic headache (CGHA). No meta-analysis has investigated the effectiveness of SMT exclusively for CGHA.

OBJECTIVE

To evaluate the effectiveness of SMT for CGHA.

DATABASES AND DATA TREATMENT

Five databases identified randomized controlled trials comparing SMT with other manual therapies. The PEDro scale assessed the risk-of-bias. Pain and disability data were extracted and converted to a common scale. A random effects model was used for several follow-up periods. GRADE described the quality of evidence.

RESULTS

Seven trials were eligible. At short-term follow-up, there was a significant, small effect favouring SMT for pain intensity (mean difference [MD] -10.88 [95% CI, -17.94, -3.82]) and small effects for pain frequency (standardized mean difference [SMD] -0.35 [95% CI, -0.66, -0.04]). There was no effect for pain duration (SMD - 0.08 [95% CI, -0.47, 0.32]). There was a significant, small effect favouring SMT for disability (MD - 13.31 [95% CI, -18.07, -8.56]). At intermediate follow-up, there was no significant effects for pain intensity (MD - 9.77 [-24.21 to 4.68]) and a significant, small effect favouring SMT for pain frequency (SMD - 0.32 [-0.63 to - 0.00]). At long-term follow-up, there was no significant effects for pain intensity (MD - 0.76 [-5.89 to 4.37]) and for pain frequency (SMD - 0.37 [-0.84 to 0.10]).

CONCLUSION

For CGHA, SMT provides small, superior short-term benefits for pain intensity, frequency and disability, but not pain duration, however, high-quality evidence in this field is lacking. The long-term impact is not significant.

SIGNIFICANCE

CGHA are a common headache disorder. SMT can be considered an effective treatment modality, with this review suggesting it providing superior, small, short-term effects for pain intensity, frequency and disability when compared with other manual therapies. These findings may help clinicians in practice better understand the treatment effects of SMT alone for CGHA.

Transarterial CT angiography for surgical planning of spinal dural arteriovenous fistula

OBJECTIVE

We report a novel method to provide excellent anatomical depiction of a dural arteriovenous fistula (dAVF) for surgical planning.

METHODS

A 78-year-old female presented with progressive back pain, deteriorating mobility and urinary incontinence with a background of obesity and severe osteoarthritis. Initial MRI suspected dAVF and subsequent spinal angiography encountered an extremely tortuous and arteriosclerotic aorta, hence catheterisation of the segmental-intercostal and lumbar vessels proved challenging. Contrast injection into the aortic arch via a pigtail catheter for arterial-phase CT angiogram of the descending aorta was performed.

RESULTS

This modality of imaging delineated the dAVF showing extensive involvement of the whole spine accounting for the patient's symptoms. Furthermore this allowed characterisation of bony anatomy in relation to the fistula facilitating precise surgical approach. The dAVF was successfully disconnected through a localised laminectomy centred over the lesion.

CONCLUSION

This specific technique for dAVF characterisation has not been previously reported, although trans-venous angiography has been used to some effect. In view of diagnostic and therapeutic technical difficulties that are often faced in such patients, this technique may be a useful alternative that is not only helpful in accurate diagnosis but helps in providing an invaluable guide for the surgical approach.

ADVANCES IN KNOWLEDGE

This case highlights the difficulties that one may be faced within cases of tortuous vasculature and the obese patient population. With this in mind we demonstrate how a unique hybridised technique may provide valuable alternative to the neurosciences team should such a future scenario arise.

A computational model for prediction of clot platelet content in flow-diverted intracranial aneurysms

Treatment of intracranial aneurysms with flow-diverting stents is a safe and minimally invasive technique. The goal is stable embolisation that facilitates stent endothelialisation, and elimination of the aneurysm. However, it is not fully understood why some aneurysms fail to develop a stable clot even with sufficient levels of flow reduction. Computational prediction of thrombus formation dynamics can help predict the post-operative response in such challenging cases. In this work, we propose a new model of thrombus formation and platelet dynamics inside intracranial aneurysms. Our novel contribution combines platelet activation and transport with fibrin generation, which is key to characterising stable and unstable thrombus. The model is based on two types of thrombus inside aneurysms: red thrombus (fibrin- and erythrocyte-rich) can be found in unstable clots, while white thrombus (fibrin- and platelet-rich) can be found in stable clots. The thrombus generation model is coupled to a CFD model and the flow-induced platelet index (FiPi) is defined as a quantitative measure of clot stability. Our model is validated against an in vitro phantom study of two flow-diverting stents with different sizing. We demonstrate that our model accurately predicts the lower thrombus stability in the oversized stent scenario. This opens possibilities for using computational simulations to improve endovascular treatment planning and reduce adverse events, such as delayed haemorrhage of flow-diverted aneurysms.

Positioning a proned patient with cauda equina syndrome who presents at 15 weeks gestation: a case report

Cauda equina syndrome is a neurosurgical emergency that requires prompt intervention to prevent irreversible spinal cord paralysis. This article describes how we managed a case of an obese pregnant patient who was placed in the prone position for surgery. We discuss the evidence behind the management options and choice of operating tables available.

Immunogenicity of DNA- and recombinant protein-based Alzheimer disease epitope vaccines

Alzheimer disease (AD) process involves the accumulation of amyloid plaques and tau tangles in the brain, nevertheless the attempts at targeting the main culprits, neurotoxic β-amyloid (Aβ) peptides, have thus far proven unsuccessful for improving cognitive function. Important lessons about anti-Aβ immunotherapeutic strategies were learned from the first active vaccination clinical trials. AD progression could be safely prevented or delayed if the vaccine (1) induces high titers of antibodies specific to toxic forms of Aβ; (2) does not activate the harmful autoreactive T cells that may induce inflammation; (3) is initiated before or at least at the early stages of the accumulation of toxic forms of Aβ. Data from the recent passive vaccination trials with bapineuzumab and solanezumab also indicated that anti-Aβ immunotherapy might be effective in reduction of the AD pathology and even improvement of cognitive and/or functional performance in patients when administered early in the course of the disease. For the prevention of AD the active immunization strategy may be more desirable than passive immunotherapy protocol and it can offer the potential for sustainable clinical and commercial advantages. Here we discuss the active vaccine approaches, which are still in preclinical development and vaccines that are already in clinical trials.

Liposome-encapsulated peptides protect against experimental allergic encephalitis

Multiple sclerosis (MS) is a severe inflammatory and neurodegenerative disease with an autoimmune background. Despite the variety of therapeutics available against MS, the development of novel approaches to its treatment is of high importance in modern pharmaceutics. In this study, experimental autoimmune encephalomyelitis (EAE) in Dark Agouti rats has been treated with immunodominant peptides of the myelin basic protein (MBP) encapsulated in mannosylated small unilamellar vesicles. The results show that liposome-encapsulated MBP_46–62 is the most effective in reducing maximal disease score during the first attack, while MBP_124–139 and MBP_147–170 can completely prevent the development of the exacerbation stage. Both mannosylation of liposomes and encapsulation of peptides are critical for the therapeutic effect, since neither naked peptides nor nonmannosylated liposomes, loaded or empty, have proved effective. The liposome-mediated synergistic effect of the mixture of 3 MBP peptides significantly suppresses the progression of protracted EAE, with the median cumulative disease score being reduced from 22 to 14 points, compared to the placebo group; prevents the production of circulating autoantibodies; down-regulates the synthesis of Th1 cytokines; and induces the production of brain-derived neurotrophic factor in the central nervous system. Thus, the proposed formulation ameliorates EAE, providing for a less severe first attack and rapid recovery from exacerbation, and offers a promising therapeutic modality in MS treatment.—Belogurov, A. A., Jr., Stepanov, A. V., Smirnov, I. V., Melamed, D., Bacon, A., Mamedov, A. E., Boitsov, V. M., Sashchenko, L. P., Ponomarenko, N. A., Sharanova, S. N., Boyko, A. N., Dubina, M. V., Friboulet, A., Genkin, D. D., Gabibov, A. G. Liposome-encapsulated peptides protect against experimental allergic encephalitis.

[Therapeutic effect of encapsulated into the nanocontainers MBP immunodominant peptides on EAE development in DA rats]

Multiple Sclerosis (MS) is a serve autoimmune neurodegenerative disease. Development of innovative approaches of MS treatment is of a high priority in the modern immunology and pharmacy. In the present study we showed high therapeutic efficiency of immunodominant peptides of myelin basic protein (MBP) incorporated into the monolayer mannosylated liposomes on the development of experimental autoimmune encephalomyelitis (EAE) in DA rats. MBP is a component ofoligodendrocytes' membrane, which form axonal sheath, and is one of the major autoantigens in MS. We analyzed binding pattern ofanti-MBP autoantibodies from MS patients using previously designed MBP epitope library. Utilizing the same approach we investigated pool of anti-MBP antibodies from SJL/J and C57/BL6 mice and DA rats with induced EAE. The most relevant rodent model to MS was EAE in DA rats according to the autoantibodies' binding pattern. We selected three immunodominant MBP fragments encapsulated in monolayer mannosylated liposomes for the following treatment of verified DA rodent model. MBP fragment 46-62 was the most effective in reducing of the first EAE attack, whereas MBP 124-139 and 147-160 inhibited development of pathology during remission stage. Simultaneous administration of these peptides in liposomes significantly decreased level of anti-MBP antibodies. Synergetic therapeutic effect of MBP fragments reduced integral disease score by inhibiting first EAE wave and subsequent remission, thus, our findings disclosure novel approaches for efficient treatment of Multiple Sclerosis.

Galanin acts as a trophic factor to the central and peripheral nervous systems

The neuropeptide galanin is widely, but not ubiquitously, expressed in the adult nervous system. Its expression is markedly up-regulated in many neuronal tissues after nerve injury or disease. Over the last 10 years, we have demonstrated that the peptide plays a developmental survival role to subsets of neurons in the peripheral and central nervous systems with resulting phenotypic changes in neuropathic pain and cognition. Galanin also appears to play a trophic role to adult sensory neurons following injury, via activation of GalR2, by stimulating neurite outgrowth. Furthermore, galanin also plays a neuroprotective role to the hippocampus following excitotoxic injury, again mediated by activation of GalR2. Most recently, we have shown that galanin expression is markedly up-regulated in multiple sclerosis (MS) lesions and in the experimental autoimmune encephalomyelitis (EAE) model of MS. Over-expression of galanin in transgenic mice abolishes disease in the EAE model, whilst loss-of-function mutations in galanin or GalR2 increase disease severity. In summary, these studies demonstrate that a GalR2 agonist might have clinical utility in a variety of human diseases that affect the nervous system.

Strategies for induction of catalytic antibodies toward HIV-1 glycoprotein gp120 in autoimmune prone mice

Tremendous efforts to produce an efficient vaccine for HIV infection have been unsuccessful. The ability of HIV to utilize sophisticated mechanisms to escape killing by host immune system rises dramatic problems in the development of antiviral therapeutics. The HIV infection proceeds by interaction of coat viral glycoprotein gp120 trimer with CD4(+) receptor of the lymphocyte. Thus this surface antigen may be regarded as a favorable target for immunotherapy. In the present study, we have developed three different strategies to produce gp120-specific response in autoimmune prone mice (SJL strain) as potential tools for production "catalytic vaccine". Therefore (i) reactive immunization by peptidylphosphonate, structural part of the coat glycoprotein, (ii) immunization by engineered fused epitopes of gp120 and encephalogenic peptide, a part of myelin basic protein, and (iii) combined vaccination by DNA and corresponding gp120 fragments incorporated into liposomes were investigated. In the first two cases monoclonal antibodies and their recombinant fragments with amidolytic and gp120-specific proteolytic activities were characterized. In the last case, catalytic antibodies with virus neutralizing activity proved in cell line models were harvested.

The ‘Co-Delivery’ Approach to Liposomal Vaccines: Application to the Development of influenza-A and hepatitis-B Vaccine Candidates

DNA vaccination with mammalian-expressible plasmid DNA encoding protein antigens is known to be an effective means to elicit cell-mediated immunity, sometimes in the absence of a significant antibody response. This may be contrasted with protein vaccination, which gives rise to antibody responses with little evidence of cell-mediated immunity. This has led to considerable interest in DNA vaccination as a means to elicit cell-mediated immune responses against conserved viral antigens or intracellular cancer antigens, for the purpose of therapeutic vaccination. However, almost all current vaccines are used prophylactically and work by producing antibodies rather than cell mediated immune responses. In the present study we have therefore explored the combination of DNA and protein forms of an antigen using two exemplary prophylactic vaccine antigens, namely inactivated influenza virion and hepatitis-B surface antigen. We studied the effects of various combinations of DNA and protein on the antibody response. Co-administration of soluble forms of DNA and protein representations of the same antigen gave rise to the same level of antibody response as if protein were administered alone. In contrast, we found that when these antigens are entrapped in the same liposomal compartment, that there was a strong synergistic effect on the immune response, which was much greater than when either antigen was administered alone, or in various other modes of combination (e.g. co-administration as free entities, also pooled liposomal formulations where the two materials were contained in separate liposomal vehicles in the same suspension). The synergistic effect of liposomally co-entrapped DNA and protein exceeded, markedly, the well known adjuvant effects of plasmid DNA and liposomes. We have termed this new approach to vaccination 'co-delivery' and suggest that it may derive from the simultaneous presentation of antigen via MHC class-I (DNA) and MHC class-II (protein) pathways to CD8+ and CD4+ cells at the same antigen presenting cell--a mode of presentation that would commonly occur with live viral pathogens. We conclude that co-delivery is a very effective means to generate protective antibody responses against viral pathogens.

A role for liposomes in genetic vaccination

Genetic immunization by the use of plasmid DNA encoding antigens from bacteria, viruses, protozoa and cancers has often led to protective humoral and cell-mediated immunity, and has some practical advantages over conventional vaccines. However, naked DNA vaccines can be degraded by nucleases in situ, are unable to target antigen presenting cells (APCs), and exhibit poor performance when administered by routes other than the intramuscular, all of which have reduced the value of the approach. We have been able to avoid DNA degradation and also target DNA to APCs by the use of liposomes as DNA vaccine carriers. Entrapment of plasmid DNA within the aqueous spaces of cationic liposomes is effected by a one step procedure which results in most of the DNA being incorporated into a freeze dried, ready to use preparation. Animal experiments have shown that immunization by the intramuscular or the subcutaneous route with liposome-entrapped plasmid DNA encoding the hepatitis B surface antigen leads to much greater humoral (IgG subclasses) and cell mediated (splenic IFN-gamma) immune responses than with naked DNA. In other experiments with a plasmid DNA encoding a model antigen (ovalbumin), a cytotoxic T lymphocyte (CTL) response was also observed. These results could be explained by the ability of liposomes to protect their DNA content from local nucleases and direct it to APCs in the lymph nodes draining the injected site.

The importance of the short-term leaching dynamics of wood preservatives

The potential environmental impacts from the use of treated timber in aquatic areas is under scrutiny as a result of environmental legislation and reports of the deleterious environmental effects around treated structures. In this study leaching experiments of up to 3 weeks duration were conducted on two species of chromated copper arsenate treated timber, dried for different periods of time. Increased drying time significantly reduced leaching of Cr and As. The addition of a synthetic humic acid increased leaching of Cu and As, but reduced leaching of Cr. Putative risk assessments conducted using short-term copper leaching data suggested protocol design may influence decisions made regarding the environmental acceptability of such preservatives.

Targeted disruption of galanin: new insights from knock-out studies

The neuropeptide galanin has a widespread but no means ubiquitous expression pattern in the nervous and endocrine systems. Profound changes in the levels and distribution of the peptide occur in a range of path-physiological situations including nerve injury or damage and alterations in the circulating levels of a number of hormones. There is now a substantial body of work to indicate that galanin plays an important biological role as a regulator of neurotransmitter and hormone release in the adult. The recent generation of mice carrying a loss-of-function mutation within the galanin gene has allowed us new insights into the physiological actions of galanin. In this manuscript we detail three sets of data relating to the major phenotypic effects thus far delineated, putting them in the context of existing published data. These studies demonstrate that galanin acts as a developmental and trophic factor to subsets of neurons in the nervous and neuroendocrine systems.

Induction of a cytotoxic T lymphocyte (CTL) response to plasmid DNA delivered via Lipodine liposomes

We have previously shown that liposome-mediated plasmid DNA immunisation may be a preferred alternative to the use of naked DNA. Lipodine DNA formulations consist of liposomes containing entrapped DNA plasmid by the dehydration-rehydration (DRV) method. Such liposome formulations are distinct from liposomes with externally complexed DNA in that the majority of the DNA is "internal" to the liposome structure and hence protected from DNAase degradation. Previous studies on the immune response induced by DNA vaccines entrapped in Lipodine have focused on the humoural response. In the present study, we have expanded the analysis profile in order to include the cytotoxic T lymphocyte (CTL) component of the immune response. We have analysed the immune response induced by DNA entrapped in Lipodine compared to that induced by DNA alone when delivered subcutaneously, a route of administration not normally inducing significant plasmid DNA mediated immune activation. Our results indicate that delivery of a small dose of plasmid DNA in Lipodine results in an improved antibody response to the plasmid encoded antigen and a strong antigen specific CTL response compared to that induced by DNA delivered alone.

Galanin regulates the postnatal survival of a subset of basal forebrain cholinergic neurons

The neuropeptide galanin colocalizes with choline acetyltransferase, the synthetic enzyme for acetylcholine, in a subset of cholinergic neurons in the basal forebrain of rodents. Chronic intracerebroventricular infusion of nerve growth factor induces a 3- to 4-fold increase in galanin gene expression in these neurons. Here we report the loss of a third of cholinergic neurons in the medial septum and vertical limb diagonal band of the basal forebrain of adult mice carrying a targeted loss-of-function mutation in the galanin gene. These deficits are associated with a 2-fold increase in the number of apoptotic cells in the forebrain at postnatal day seven. This loss is associated with marked age-dependent deficits in stimulated acetylcholine release, performance in the Morris water maze, and induction of long-term potentiation in the CA1 region of the hippocampus. These data provide unexpected evidence that galanin plays a trophic role to regulate the development and function of a subset of septohippocampal cholinergic neurons.

Targeted disruption of the galanin gene reduces the number of sensory neurons and their regenerative capacity

The neuropeptide galanin is expressed developmentally in the dorsal root ganglion (DRG) and is rapidly up-regulated 120-fold after peripheral nerve section in the adult. Here we report that adult mice carrying a loss-of-function mutation in the galanin gene have a 13% reduction in the number of cells in the DRG associated with a 24% decrease in the percentage of neurons that express substance P. These deficits are associated with a 2.8- and 2.6-fold increase in the number of apoptotic cells in the DRG at postnatal days 3 and 4, respectively. After crush injury to the sciatic nerve, the rate of peripheral nerve regeneration is reduced by 35% with associated long-term functional deficits. Cultured DRG neurons from adult mutant mice demonstrate similar deficits in neurite number and length. These results identify a critical role for galanin in the development and regeneration of sensory neurons.

Carbohydrate biopolymers enhance antibody responses to mucosally delivered vaccine antigens

We have evaluated the ability of two carbohydrate biopolymers, chitosan and gellan, to enhance antibody responses to subunit influenza virus vaccines delivered to the respiratory tracts of mice. Groups of mice were vaccinated three times intranasally (i.n.) with 10 microg of purified influenza B/Panama virus surface antigens (PSAs), which consist of hemagglutinin (HA) and neuraminidase (NA), either alone or admixed with chitosan or gellan solutions. Separate groups were vaccinated subcutaneously (s.c.) with PSAs adsorbed to Alhydrogel or chitosan or gellan alone i.n. Serum antibody responses were determined by enzyme-linked immunosorbent assay (ELISA) for influenza virus-specific immunoglobulin G (IgG) and by HA inhibition (HAI) and NA inhibition (NAI) assays. The local respiratory immune response was measured by assaying for influenza virus-specific IgA antibody in nasal secretions and by enumerating nasal and pulmonary lymphocytes secreting IgA, IgG, and IgM anti-influenza virus-specific antibodies by enzyme-linked immunospotting (ELISPOT). When administered alone i.n., B/Panama PSA was poorly immunogenic. Parenteral immunization with B/Panama PSA with Alhydrogel elicited high titers of anti-B/Panama antibodies in serum but a very poor respiratory anti-B/Panama IgA response. In contrast, i.n. immunization with PSA plus chitosan stimulated very strong local and systemic anti-B/Panama responses. Gellan also enhanced the local and serum antibody responses to i.n. PSA but not to the same extent as chitosan. The ability of chitosan to augment the immunogenicity of influenza vaccines given i.n. was confirmed using PSA prepared from an influenza A virus (A/Texas H1N1).