Outcome and feasibility of radiotherapy bridging in large B-cell lymphoma patients receiving CD19 CAR T in the UK

Radiotherapy (RT) has potential synergistic effects with chimeric antigen receptor (CAR) T but is not widely used as bridging therapy due to logistical challenges and lack of standardised protocols. We analysed RT bridging in a multicentre national cohort of large B-cell lymphoma patients approved for 3L axicabtagene ciloleucel or tisagenlecleucel across 12 UK centres. Of 763 approved patients, 722 were leukapheresed, 717 had data available on bridging therapy. 169/717 (24%) received RT bridging, 129 as single modality and 40 as combined modality treatment (CMT). Of 169 patients, 65.7% had advanced stage, 36.9% bulky disease, 86.5% elevated LDH, 41.7% international prognostic index (IPI) ≥3 and 15.2% double/triple hit at the time of approval. Use of RT bridging varied from 11% to 32% between centres and increased over time. Vein-to-vein time and infusion rate did not differ between bridging modalities. RT-bridged patients had favourable outcomes with 1-year progression-free survival (PFS) of 56% for single modality and 47% for CMT (1-year PFS 43% for systemic bridging). This is the largest cohort of LBCL patients receiving RT bridging prior to CAR T reported to date. Our results show that RT bridging can be safely and effectively used even in advanced stage and high-risk disease, with low dropout rates and excellent outcomes.

Improved outcomes of large B-cell lymphoma patients treated with CD19 CAR T in the UK over time

The success of CD19 Chimeric antigen receptor (CAR) T-cell therapy in large B-cell lymphoma (LBCL) has been partially offset by toxicity and logistical challenges, which off-the-shelf agents like CD20xCD3 bispecific antibodies might potentially overcome. However, when using CAR T outcomes as the 'standard-of-care comparator̕ for relapsed/refractory (r/r) LBCL, a potential learning curve with implementing a novel, complex therapy like CAR T needs to be considered. To address this, we analysed 726 UK patients intended to be treated with CD19 CAR T for r/r LBCL and compared outcomes between the first year of the national CAR T programme (Era 1; 2019) and the more recent treatment era (Era 2; 2020-2022). We identified significant improvements for Era 2 versus Era 1 in dropout rate (17% vs. 27%, p = 0.001), progression-free survival (1-year PFS 50% vs. 32%, p < 0.001) and overall survival (1-year OS 60% vs. 40%, p < 0.001). We also observed increased use of bridging therapy, improvement in bridging outcomes, more tocilizumab/corticosteroid use, reduced high-grade cytokine release syndrome (4% vs. 9%, p = 0.01) and intensive care unit admissions (20% vs. 32%, p = 0.001). Our results demonstrate significant improvement in CAR T outcomes over time, highlighting the importance of using up-to-date clinical data when comparing CAR T against new treatment options for r/r LBCL.

The 2023 Impact of Inflammatory Bowel Disease in Canada: Epidemiology of IBD

Inflammatory bowel disease (IBD), consisting of Crohn's disease and ulcerative colitis, is recognized across the world, though Canada has among the highest burdens of IBD in the world. The Canadian Gastro-Intestinal Epidemiology Consortium (CanGIEC) led a six-province study that demonstrated the compounding prevalence of IBD in Canada from 400 per 100,000 in 2002 to 636 per 100,000 in 2014. The prevalence in 2023 is estimated at 825 per 100,000, meaning that over 320,000 people in Canada are living with IBD. Prevalence is forecasted to rise by 2.44% per year such that 1.1% of the population, 470,000 Canadians, will live with IBD by 2035. The overall incidence of IBD in 2023 is 30 per 100,000 person-years, indicating that over 11,000 Canadians will be newly diagnosed with IBD in 2023. Incidence is forecasted to rise by 0.58% per year up to 32.1 per 100,000 by 2035. The rising incidence of IBD is propelled by pediatric-onset IBD, which is rising by 1.23% per year from 15.6 per 100,000 in 2023 to 18.0 per 100,000 in 2035. In contrast, incidence rates among adults and seniors are relatively stable. Understanding the determinates of IBD has expanded through prospective cohort studies such as the Crohn's and Colitis Canada Genetic, Environmental, Microbial (CCC-GEM) project. Consensus recommendations towards diet, lifestyle, behavioural and environmental modifications have been proposed by international organizations with the goal of optimizing disease control and ultimately preventing the development of IBD. Despite these efforts, Canadian healthcare systems will need to prepare for the rising number of people living with IBD.

The 2023 Impact of Inflammatory Bowel Disease in Canada: Mental Health and Inflammatory Bowel Disease

Psychiatric disorders are 1.5 to 2 times more prevalent in persons with inflammatory bowel disease (IBD) than in the general population, with pooled prevalence estimates of 21% for clinical anxiety and 15% for depression. Rates are even higher when considering mental health symptoms, as nearly one-third of persons with IBD experience elevated anxiety symptoms and one-quarter experience depression symptoms. Rates of these symptoms were much higher during periods of disease activity, more common in women than men, and more common in Crohn's disease than ulcerative colitis. There is robust evidence of the detrimental effects of comorbid depression and anxiety on the subsequent course of IBD based on longitudinal studies tracking outcomes over time. However, psychiatric disorders and IBD have bidirectional effects, with each affecting risk of the other. Elevated mental health concerns have been consistently associated with greater healthcare utilization and costs related to IBD. There is some signal that low resilience in adolescence could be a risk factor for developing IBD and that enhancing resilience may improve mental health and intestinal disease outcomes in IBD. Psychological therapies used to treat anxiety and depression occurring in the context of IBD have been shown to significantly improve the quality of life for persons with IBD and reduce anxiety and depression. There is less evidence in regard to the impact of psychotropic medications on mental health or disease outcomes in persons with IBD. There is consensus, however, that mental health must be addressed as part of comprehensive IBD care for children and adults.

CAR T in patients with large B-cell lymphoma not fit for autologous transplant

Large B-cell lymphoma (LBCL) patients with comorbidities and/or advanced age are increasingly considered for treatment with CD19 CAR T, but data on the clinical benefit of CAR T in the less fit patient population are still limited. We analysed outcomes of consecutive patients approved for treatment with axicabtagene ciloleucel (axi-cel) or tisagenlecleucel (tisa-cel) by the UK National CAR T Clinical Panel, according to fitness for autologous stem cell transplant (ASCT). 81/404 (20%) of approved patients were deemed unfit for ASCT. Unfit patients were more likely to receive tisa-cel versus axi-cel (52% vs. 48%) compared to 20% versus 80% in ASCT-fit patients; p < 0.0001. The drop-out rate from approval to infusion was significantly higher in the ASCT-unfit group (34.6% vs. 23.5%; p = 0.042). Among infused patients, response rate, progression-free and overall survival were similar in both cohorts. CAR T was well-tolerated in ASCT-unfit patients with an incidence of grade ≥3 cytokine release syndrome and neurotoxicity of 2% and 11%, respectively. Results from this multicentre real-world cohort demonstrate that CD19 CAR T can be safely delivered in carefully selected older patients and patients with comorbidities who are not deemed suitable for transplant.

Health care utilization differences between First Nations people and the general population with inflammatory bowel disease: a retrospective cohort study from Saskatchewan, Canada

BACKGROUND

Indigenous people in Canada often face barriers to access specialized care, with limited data in evaluating health care utilization among Indigenous people with inflammatory bowel disease (IBD). We aimed to compare health care utilization between First Nations patients and those in the general population diagnosed with IBD in Saskatchewan.

METHODS

We conducted a patient-oriented, population-based, retrospective cohort study by linking administrative health databases of Saskatchewan between fiscal years 1998/99 and 2017/18. We designed and completed this study in partnership with Indigenous patients and family advocates. We applied a validated algorithm to identify IBD incident cases and then used the self-declared First Nations status variable to divide those cases. We applied a 1:5 ratio for age and sex matching and used Cox proportional models to assess associations. Hazard ratios (HRs) and 95% confidence intervals (CIs) were reported.

RESULTS

We created a matched cohort with 696 IBD incident cases: 116 First Nations patients and 580 patients in the general population. We observed differences between the groups for IBD-specific hospital admissions (HR 1.33, 95% CI 1.01-1.75), IBD-related hospital admissions (HR 1.55, 95% CI 1.20-2.01), medication claims for IBD (HR 0.52, 95% CI 0.41-0.65) and 5-aminosalicylic acid claims (HR 0.56, 95% CI 0.45-0.71) adjusting by rural or urban residence and diagnosis type. There were no significant differences in the hazard rate of outpatient gastroenterology visits (HR 1.13, 95% CI 0.90-1.41), colonoscopies (HR 1.14, 95% CI 0.92-1.41) and surgeries for IBD (HR 1.14, 95% CI 0.80-1.64).

INTERPRETATION

We identified that First Nations patients diagnosed with IBD had a higher rate of hospital admissions owing to IBD than patients in the general population diagnosed with IBD. We also found an inverse association between First Nations status and having prescription medication claims for IBD.

Increasing Prevalence and Stable Incidence Rates of Inflammatory Bowel Disease Among First Nations: Population-Based Evidence From a Western Canadian Province

BACKGROUND

There is limited to no evidence of the prevalence and incidence rates of inflammatory bowel disease (IBD) among Indigenous peoples. In partnership with Indigenous patients and family advocates, we aimed to estimate the prevalence, incidence, and trends over time of IBD among First Nations (FNs) since 1999 in the Western Canadian province of Saskatchewan.

METHODS

We conducted a retrospective population-based study linking provincial administrative health data from the 1999-2000 to 2016-2017 fiscal years. An IBD case definition requiring multiple health care contacts was used. The prevalence and incidence data were modeled using generalized linear models and a negative binomial distribution. Models considered the effect of age groups, sex, diagnosis type (ulcerative colitis [UC], Crohn disease [CD]), and fiscal years to estimate prevalence and incidence rates and trends over time.

RESULTS

The prevalence of IBD among FNs increased from 64/100,000 (95% confidence interval [CI], 62-66) in 1999-2000 to 142/100,000 (95% CI, 140-144) people in 2016-2017, with an annual average increase of 4.2% (95% CI, 3.2%-5.2%). Similarly, the prevalence of UC and CD, respectively, increased by 3.4% (95% CI, 2.3%-4.6%) and 4.1% (95% CI, 3.3%-4.9%) per year. In contrast, the incidence rates of IBD, UC, and CD among FNs depicted stable trends over time; no statistically significant changes were observed in the annual change trend tests. The ratio of UC to CD was 1.71.

CONCLUSIONS

We provided population-based evidence of the increasing prevalence and stable incidence rates of IBD among FNs. Further studies are needed in other regions to continue understanding the patterns of IBD among Indigenous peoples.

OP0039 ALPN-303, AN ENHANCED, POTENT DUAL BAFF/APRIL ANTAGONIST ENGINEERED BY DIRECTED EVOLUTION FOR THE TREATMENT OF SYSTEMIC LUPUS ERYTHEMATOSUS (SLE) AND OTHER B CELL-RELATED AUTOIMMUNE DISEASES

Background:

BAFF and APRIL are TNF superfamily members that form homo- and heteromultimers that bind TACI and BCMA on B cells; BAFF also binds BAFF-R. BAFF and APRIL support B cell development, differentiation, and survival, particularly for plasmablasts and plasma cells, and play critical roles in the pathogenesis of B cell-related autoimmune diseases. In nonclinical models, inhibition of either BAFF or APRIL alone mediates relatively modest effects, whereas their co-neutralization dramatically reduces B cell function, including antibody production. Fc fusions of wild-type (WT) TACI (e.g. atacicept and telitacicept) target both BAFF and APRIL and have demonstrated promising clinical potential in e.g. systemic lupus erythematosus (SLE) and IgA nephropathy but have not yet clearly exhibited long-term and/or complete disease remissions.

Objectives:

To generate a dual BAFF/APRIL antagonist with inhibitory activity superior to WT TACI and BCMA and with the potential to improve clinical outcomes in B cell-mediated diseases.

Methods:

Our directed evolution platform was used to identify a potent variant TNFR domain (vTD) of TACI that exhibits significantly enhanced affinity for BAFF and APRIL as compared to WT TACI; this TACI vTD domain was fused to a human IgG Fc to generate the therapeutic candidate ALPN-303. ALPN-303 was evaluated for functional activity in: 1) human lymphocyte assays, 2) the NOD.Aec1Aec2 spontaneous model of Sjogren’s syndrome (SjS), 3) the bm12-induced mouse model of lupus, 4) the (NZB/NZW)F1 spontaneous model of lupus, and 5) preclinical rodent and cynomolgus monkey pharmacokinetic/pharmacodynamic studies.

Results:

ALPN-303 inhibited BAFF- and APRIL-mediated signaling in vitro in human lymphocyte assays, with significantly lower IC50 values than WT TACI-Fc and belimumab comparators. In all mouse models evaluated, administration of ALPN-303 rapidly and significantly reduced key lymphocyte subsets including plasma cells, germinal center B cells, and follicular T helper cells. ALPN-303 significantly reduced autoantibodies and sialadenitis in the spontaneous SjS model, inhibited glomerular IgG deposition in the bm12-induced model of lupus, and potently suppressed anti-dsDNA autoAbs, blood urea nitrogen levels, proteinuria, sialadenitis, kidney lesions, and renal immune complex deposition in the NZB/W lupus model. As compared to WT TACI-Fc, ALPN-303 exhibited higher serum exposure and significantly and persistently decreased titers of serum IgM, IgG, and IgA antibodies in mice and cynomolgus monkeys (Figure 1).

Figure 1.

ALPN-303 induces more potent suppression, as compared to WT TACI-Fc, of serum immunoglobulins following a single 9 mg/kg IV infusion (on Day 0; arrows) in female cynomolgus monkeys.

Conclusion:

ALPN-303 is a potent BAFF/APRIL antagonist derived from our directed evolution platform that consistently demonstrates encouraging immunomodulatory activity and efficacy in vitro and in vivo, superior in preclinical studies to anti-BAFF antibody and WT TACI-Fc. This novel Fc fusion molecule demonstrates favorable preliminary developability characteristics, including higher serum exposures and more potent immunosuppressive activities, which may enable lower clinical doses and/or longer dosing intervals than WT TACI-Fc therapeutics. ALPN-303 may thus be an attractive development candidate for the treatment of multiple autoimmune and inflammatory diseases, particularly B cell-related diseases such as SLE, SjS, and other connective tissue diseases. Preclinical development is underway to enable the initiation of clinical trials later this year.

Disclosure of Interests:

Stacey R. Dillon Shareholder of: Alpine Immune Sciences, Bristol Myers Squibb, Employee of: Alpine Immune Sciences, Bristol Myers Squibb, Lawrence S. Evans Shareholder of: Alpine Immune Sciences, Employee of: Alpine Immune Sciences, Katherine E. Lewis Shareholder of: Alpine Immune Sciences, Employee of: Alpine Immune Sciences, Jing Yang Shareholder of: Alpine Immune Sciences, Employee of: Alpine Immune Sciences, Mark W. Rixon Shareholder of: Alpine Immune Sciences, Employee of: Alpine Immune Sciences, Joe Kuijper Shareholder of: Alpine Immune Sciences, Employee of: Alpine Immune Sciences, Dan Demonte Shareholder of: Alpine Immune Sciences, Employee of: Alpine Immune Sciences, Janhavi Bhandari Shareholder of: Alpine Immune Sciences, Employee of: Alpine Immune Sciences, Steve Levin Shareholder of: Alpine Immune Sciences, Employee of: Alpine Immune Sciences, Kayla Kleist Shareholder of: Alpine Immune Sciences, Employee of: Alpine Immune Sciences, Sherri Mudri Shareholder of: Alpine Immune Sciences, Employee of: Alpine Immune Sciences, Susan Bort Shareholder of: Alpine Immune Sciences, Employee of: Alpine Immune Sciences, Daniel Ardourel Shareholder of: Alpine Immune Sciences, Employee of: Alpine Immune Sciences, Michelle A. Seaberg Shareholder of: Alpine Immune Sciences, Employee of: Alpine Immune Sciences, Rachel Wang Shareholder of: Alpine Immune Sciences, Employee of: Alpine Immune Sciences, Chelsea Gudgeon Shareholder of: Alpine Immune Sciences, Employee of: Alpine Immune Sciences, Russell Sanderson Shareholder of: Alpine Immune Sciences, Employee of: Alpine Immune Sciences, Martin F. Wolfson Shareholder of: Alpine Immune Sciences, Employee of: Alpine Immune Sciences, Jan Hillson Shareholder of: Alpine Immune Sciences, Employee of: Alpine Immune Sciences, Stanford L. Peng Shareholder of: Alpine Immune Sciences, Employee of: Alpine Immune Sciences

A19 HEALTH CARE UTILIZATION DIFFERENCES BETWEEN FIRST NATIONS AND THE GENERAL POPULATION WITH INFLAMMATORY BOWEL DISEASE IN SASKATCHEWAN

Background

Indigenous patients with inflammatory bowel disease (IBD) have expressed concerns about barriers to access IBD care. The limited evidence of IBD among Indigenous people highlights the need for studies evaluating access to IBD care in this population.

Aims

We aimed to compare health care utilization between First Nations (FNs) and individuals from the general population (GP) diagnosed with IBD in Saskatchewan (SK).

Methods

A population-based retrospective cohort study was conducted using administrative health databases of SK from 1998 to 2017 fiscal years. As a patient-oriented research initiative, outcomes of interest were chosen in collaboration with Indigenous patients and family advocates. A validated algorithm requiring multiple health care contacts was applied to identify incident IBD cases. The self-declared FN status variable was used to divide IBD cases between FNs and the general population (GP). To balance the groups, 1:5 age and sex matching was applied. Cox-proportional models were used to estimate hazard ratios (HRs) and 95% confidence intervals (95%CI). Stratified analysis was completed for those diagnosed before and after 2008 (pre- and post-biologic eras).

Results

A matched cohort with 696 IBD incident cases was created (FN=116, GP=580). Comparing health care utilization of FNs and individuals from the GP with IBD, there were no statistically significant differences in outpatient gastroenterology visits (FNs=81.0%, GP=83.6%), colonoscopies (FNs=91.4%, GP=86.9%), and surgeries for IBD (FNs=31.0%, GP=33.5%). We observed differences in prescription claims for any medication for IBD (FNs=79.3%, GP=89.3%) and 5-aminosalicylic acid (5-ASA) claims (FNs=75.9%, GP=81.4%). The HRs adjusted by rural/urban residence and diagnostic type showed differences in prescription claims for any IBD medication (HR=0.52, 95%CI 0.41–0.65) and 5-ASA (HR=0.57, 95%CI 0.45–0.72). In the pre-biologic era, FNs had a lower risk of having a prescription claim for any IBD medication (HR=0.32, 95%CI 0.23–0.45) and 5-ASA (HR=0.33, 95%CI 0.24–0.47), respectively. These differences were not significant in the post-biologic era.

Conclusions

Our study identified an inverse association between FN status and having prescription medication claims for IBD in SK. We considered multiple confounding variables when evaluating this association but could not control by disease severity. Thus, this association might reflect a barrier to access IBD medications or that FNs with IBD might present a milder disease. Further studies should continue evaluating access to IBD care, medication use, and disease severity among FNs living with IBD.

Funding Agencies

Saskatchewan Centre for Patient-Oriented Research (SCPOR), Saskatchewan Health Research Foundation (SHRF), and College of Medicine, University of Saskatchewan.

SAT0196 A DOUBLE BLIND, PLACEBO CONTROLLED, SINGLE ASCENDING DOSE (SAD) AND MULTIPLE ASCENDING DOSE (MAD) STUDY OF ALPN-101, A FIRST-IN-CLASS DUAL ICOS/CD28 ANTAGONIST, IN HEALTHY VOLUNTEERS (HV)

Background:

ALPN-101 (ICOSL vIgD-Fc) is an Fc fusion protein of a human inducible T cell costimulatory ligand (ICOSL) variant immunoglobulin domain (vIgD™) designed to inhibit simultaneously the CD28 and ICOS inflammation pathways (1). ALPN-101 is effective in preclinical studies of lupus, arthritis, and Sjögren’s, and shows greater activity than single pathway inhibitors (2,3,4). It is in development for the treatment of multiple rheumatic and other inflammatory diseases.

Objectives:

To evaluate the safety, pharmacokinetics (PK), and pharmacodynamics (PD) of ALPN-101 in HV

Methods:

This was a first-in-human study of ALPN-101 (NCT03748836). 72 HV were allocated 4:2 to single intravenous (IV) or subcutaneous (SC) doses of ALPN-101: placebo at 0.001 – 10 mg/kg; 24 HV were allocated 6:2 to repeated IV doses of up to 1 mg/kg weekly x 4. Subjects were followed for 28 (SAD) or 49 (MAD) days to assess safety, PK, target saturation (TS) on T cells, circulating cytokines and PD, the latter based on suppression of IgG responses to keyhole limpet hemocyanin (KLH).

Results:

ALPN-101 was generally well-tolerated, with no treatment related serious adverse events, no cytokine release, no clinical immunogenicity, and no adverse trends in safety laboratories. Overall, adverse events were reported in 74.2% of subjects on ALPN-101 and 66.7% of subjects on placebo. All events were mild or moderate and resolved without sequelae. Dose-dependent increase in ALPN-101 exposure was observed from 0.012 to 10 mg/kg. The estimated t1/2was 2-8.6 days over 0.3 – 10 mg/kg. SC bioavailability was ~60% at 3 mg/kg. Minimal to modest accumulation was observed with repeat IV dosing. The TS at Cmaxincreased with dose between 0.001–0.03 mg/kg; thereafter the duration of high level TS (>95%) increased with dose (Figure 1). The duration of suppression of IgG anti-KLH response paralleled the duration of high level TS (Figure 2).

Figure 1.

Mean + SD Target Saturation of ALPN-101 on Circulating CD4+T Lymphocytes

Figure 2.

Mean + SD Serum Anti-KLH IgG Change Relative to Baseline

Conclusion:

ALPN-101 was well tolerated when administered as single doses up to 10 mg/kg or as repeated doses of up to 1 mg/kg weekly for 4 weeks, exhibiting dose-dependent PK, TS and PD including the inhibition of antibody responses to KLH immunization. These findings support future studies to evaluate the efficacy of ALPN-101 in multiple rheumatic and other inflammatory diseases.

References:

[1]Levin SD et al. Frontiers in Immunology 2020; 10:3086

[2]Evans L et al. Arthritis and Rheumatology 2019:71: Supplement: Abstract 1531

[3]Dillon S et al. Arthritis and Rheumatology 2018:70: Supplement: Abstract 136

[4]Dillon S et al. Arthritis and Rheumatology 2019:71: Supplement: Abstract 2416

Disclosure of Interests:

Jing Yang Shareholder of: Alpine Immune Sciences, Inc., Employee of: Alpine Immune Sciences, Inc., Jan Hillson Shareholder of: Alpine Immune Sciences, Inc., Employee of: Alpine Immune Sciences, Inc., Jason Lickliter Consultant of: AUD 2500 from QBiotics for participation in an expert review panel for development of their oncology phase 1 trial (in Nov 2015), Kristi Manjarrez Shareholder of: Alpine Immune Sciences, Inc., Employee of: Alpine immune sciences, Inc., Almudena Tercero Shareholder of: Alpine Immune Sciences, Inc., Employee of: Alpine Immune Sciences, Inc., Jennifer Wiley Shareholder of: Alpine Immune Sciences, Inc., Employee of: Alpine Immune Sciences, Inc., Gary Means Shareholder of: Alpine Immune Sciences, Inc., Employee of: Alpine Immune Sciences, Inc., Russell Sanderson Shareholder of: Alpine Immune Sciences, Inc., Employee of: Alpine Immune Sciences, Inc., Kay Carley Shareholder of: Alpine Immune Sciences, Inc., Employee of: Alpine Immune Sciences, Inc., Stanford L. Peng Shareholder of: Alpine Immune Sciences, Inc., Employee of: CMO and President of Alpine Immune Sciences, Inc.

THU0222 B CELL MODULATORY VARIANT TNF RECEPTOR DOMAINS (VTDS) IDENTIFIED BY DIRECTED EVOLUTION TO INHIBIT BAFF AND APRIL, ALONE OR COMBINED WITH VARIANT IG DOMAINS (VIGD™) THAT INHIBIT T CELL COSTIMULATION, FOR THE TREATMENT OF SEVERE AUTOIMMUNE AND/OR INFLAMMATORY DISEASE

Background:

BAFF and APRIL are TNF superfamily members that bind both TACI and BCMA on B cells; BAFF also binds BAFF-R. Together, BAFF and APRIL support B cell development, differentiation, and survival. Their co-neutralization dramatically reduces B cell function, including antibody production, whereas inhibition of either BAFF or APRIL alone mediates relatively modest effects.

Objectives:

While CTLA-4-based therapeutics that block T cell costimulation provide safe and moderately effective T cell inhibition in many disease settings, and while B cell targeting therapies have demonstrated promising therapeutic potential, we postulate that improved, combined BAFF and APRIL inhibition, either alone or coupled with inhibition of T cell costimulation, will provide more effective and durable relief from severe B cell-related autoimmune diseases like SLE.

Methods:

We used our directed evolution platform to identify variant domains of the TNF family receptors TACI or BCMA that exhibit enhanced affinity for BAFF and APRIL as compared to their wild-type (WT) counterparts. These variant TACI or BCMA domains (vTD), alone or together with platform-derived CTLA-4 domains (vIgD), were fused to a modified human IgG1 Fc lacking effector function, yielding a panel of immunomodulatory molecules: TACI vTD-Fc, BCMA vTD-Fc, TACI vTD/CTLA-4 vIgD-Fc, & BCMA vTD/CTLA-4 vIgD-Fc. All were evaluated for functional activity: 1)in vitroin primary human B cell & MLR assays and in a Jurkat/NF-kB reporter cell line expressing TACI, and 2)in vivoin standard immunization models, and in the bm12-induced and NZB/NZW spontaneous mouse models of lupus.

Results:

The novel engineered TACI vTD-Fc or BCMA vTD-Fc fusion proteins significantly inhibited BAFF- and APRIL-mediated signalingin vitroin TACI+Jurkat cells. TACI (or BCMA) vTD/CTLA-4 vIgD-Fc proteins also attenuated T cell activation in primary human lymphocyte assays. When administered to mice, these molecules rapidly and potently reduced key B and T cell subsets, including plasma cells, follicular T helper cells, germinal center cells, & memory T cells. Treatment with TACI vTD-Fc or TACI vTD/CTLA-4 vIgD-Fc proteins also significantly reduced titers of antigen-specific antibodies in immunized mice more so than abatacept or WT TACI-Fc, and potently suppressed anti-dsDNA autoantibodies, blood urea nitrogen levels, proteinuria, and renal immune complex deposition in the bm12 & NZB/W lupus models.

Conclusion:

Directed evolution of TNFR and IgSF domains has successfully facilitated the development of Fc fusion proteins containing TACI or BCMA vTDs, with or without fusion to CTLA-4 vIgDs. These novel immunomodulators consistently demonstrate potent immunosuppressive activity and efficacyin vitroandin vivo, appearing superior to existing and/or approved immunomodulators like belimumab, abatacept, or atacicept. Such biologics may therefore be attractive candidates for the treatment of serious autoimmune diseases, particularly B cell-related diseases such as SLE, Sjogren’s syndrome, etc.

Disclosure of Interests: :

Stacey R. Dillon Shareholder of: Shareholder of Alpine Immune Sciences, Inc., Employee of: Employee of Alpine Immune Sciences, Inc., Lawrence S. Evans Shareholder of: Shareholder of Alpine Immune Sciences, Inc., Employee of: Employee of Alpine Immune Sciences, Inc., Mark W. Rixon Shareholder of: Shareholder of Alpine Immune Sciences, Inc., Employee of: Employee of Alpine Immune Sciences, Inc., Joe Kuijper Shareholder of: Shareholder of Alpine Immune Sciences, Inc., Employee of: Employee of Alpine Immune Sciences, Inc., Dan Demonte Shareholder of: Shareholder of Alpine Immune Sciences, Inc., Employee of: Employee of Alpine Immune Sciences, Inc., Katherine E. Lewis Shareholder of: Shareholder of Alpine Immune Sciences, Inc., Employee of: Employee of Alpine Immune Sciences, Inc., Steve Levin Shareholder of: Shareholder of Alpine Immune Sciences, Inc., Employee of: Employee of Alpine Immune Sciences, Inc., Kayla Kleist Shareholder of: Shareholder of Alpine Immune Sciences, Inc., Employee of: Employee of Alpine Immune Sciences, Inc., Sherri Mudri Shareholder of: Shareholder of Alpine Immune Sciences, Inc., Employee of: Employee of Alpine Immune Sciences, Inc., Susan Bort Shareholder of: Shareholder of Alpine Immune Sciences, Inc., Employee of: Employee of Alpine Immune Sciences, Inc., Janhavi Bhandari Shareholder of: Shareholder of Alpine Immune Sciences, Inc., Employee of: Employee of Alpine Immune Sciences, Inc., Fariha Ahmed-Qadri Shareholder of: Shareholder of Alpine Immune Sciences, Inc., Employee of: Employee of Alpine Immune Sciences, Inc., Jing Yang Shareholder of: Alpine Immune Sciences, Inc., Employee of: Alpine Immune Sciences, Inc., Michelle A. Seaberg Shareholder of: Shareholder of Alpine Immune Sciences, Inc., Employee of: Employee of Alpine Immune Sciences, Inc., Rachel Wang Shareholder of: Shareholder of Alpine Immune Sciences, Inc., Employee of: Employee of Alpine Immune Sciences, Inc., Russell Sanderson Shareholder of: Alpine Immune Sciences, Inc., Employee of: Alpine Immune Sciences, Inc., Martin F. Wolfson Shareholder of: Shareholder of Alpine Immune Sciences, Inc., Employee of: Employee of Alpine Immune Sciences, Inc., Jan Hillson Shareholder of: Alpine Immune Sciences, Inc., Employee of: Alpine Immune Sciences, Inc., Stanford L. Peng Shareholder of: Alpine Immune Sciences, Inc., Employee of: CMO and President of Alpine Immune Sciences, Inc., Kristine M. Swiderek Shareholder of: Shareholder of Alpine Immune Sciences, Inc., Employee of: Employee of Alpine Immune Sciences, Inc.

A4 A FRAMEWORK TO STUDY INFLAMMATORY BOWEL DISEASE AMONG INDIGENOUS PEOPLES AND PRELIMINARY RESULTS FROM SASKATCHEWAN, CANADA

Background

Inflammatory Bowel Disease (IBD) is a chronic condition with significant life-threatening disease-related complications and reductions in quality of life if left untreated. Despite available research about IBD in the general population, there is limited-to-no evidence about IBD among Indigenous peoples in Canada and around the world.

Aims

We aimed to define a collaborative framework, estimate the prevalence and incidence rates of IBD among First Nations in Saskatchewan, Canada, and explore perceptions of IBD among Indigenous peoples in the province.

Methods

This study began when Indigenous patients shared their health experiences with IBD with research team members. An interdisciplinary research team was formed including Indigenous patient and family advocates (IPFAs, Indigenous patients living with IBD and parents of an Indigenous person with IBD), an IBD gastroenterologist, knowledge users, and Indigenous and non-Indigenous researchers. Our research team committed to raise awareness of IBD among Indigenous peoples within Indigenous communities and among health care providers and to advocate for better healthcare and well-being by providing evidence of IBD among Indigenous peoples living with IBD in Saskatchewan. We defined a mixed methodology. The first phase of the study used Saskatchewan administrative health data to estimate the prevalence and incidence rates with 95% confidence intervals (95%CI) of IBD among First Nations. The second phase of the study will use a photovoice methodology to gather “the voices” of Indigenous peoples with IBD, encouraging self-interpretation of pictures, engaging their communities, and empowering them with the study findings.

Results

The IPFAs play a critical role in the project by sharing their experiences and defining the directions of the project, as well as defining our research framework (Figure 1). Preliminary results show that the prevalence of IBD among First Nations in Saskatchewan increased from 66 (95%CI 65–68) per 100,000 population in 1999 to 148 (95%CI 145–151) per 100,000 people in 2015. In contrast, the incidence rates appear to be stable over time, 11/100,000 (95%CI 4–24) in 1999 and 11/100,000 (95%CI 5–20) in 2015. We started recruiting participants for the photovoice study in September 2019.

Conclusions

This ground-breaking patient-driven study is the first stage to improve health among Indigenous peoples living with IBD in Saskatchewan. This project will generate community-engaged knowledge and expertise to inform the development of an Indigenous IBD framework that could promote better and knowledge-based healthcare for Indigenous peoples with IBD in Canada and worldwide.

Funding Agencies

CIHRSaskatchewan Health Research Foundation (SHRF) and Saskatchewan Centre for Patient-Oriented Research (SCPOR)

Stability, fatty acid composition and sensory properties of the M. Longissimus muscle from beef steers grazing either chicory/ryegrass or ryegrass

Research has shown both production and health benefits for the use of chicory (Cichorium intybus) within ruminant diets. Despite this, little was known about the effects of this forage, containing differing fatty acid profiles and secondary plant compounds compared with ryegrass, on beef stability, fatty acid composition or sensory properties. An experiment was conducted to investigate whether the inclusion of chicory in the diet of grazing beef steers would alter these three properties in the M. Longissimus muscle when compared with beef steers grazing perennial ryegrass (Lolium perenne). Triplicate 2 ha plots were established with a chicory (cv. Puna II)/perennial ryegrass mix or a perennial ryegrass control. A core group of 36 Belgian Blue - cross steers were used within a 2-year beef finishing experiment (n=6/replicate plot). In the 2nd grazing year, steers were slaughtered as they reached a target fat class of 3. Muscle pH was checked 2 and 48 h post-slaughter. A section of the hindloin joint containing the M. Longissimus lumborum muscle was removed and a 20 mm-thick steak was cut and muscle samples were taken for analysis of vitamin E and fatty acid analysis. The remaining section of the loin was vacuum packed in modified atmosphere packs and subjected to simulated retail display. A section of the conditioned loin was used for sensory analysis. Data on pH, vitamin E concentration and colour stability in a simulated retail display showed there were no effects of including chicory in the diet of grazing beef steers on meat stability. There were also no differences found in the fatty acid composition or the overall eating quality of the steaks from the two treatments. In conclusion, there were no substantive effects of including chicory in the swards of grazing beef cattle on meat stability, fatty acid composition or sensory properties of the M. Longissimus muscle when compared with beef steers grazing ryegrass-only swards.

Comment on “The structural relationship: regression in biology”

Supplementary information relevant to structural relationship regression in biology as discussed by McArdle (1988; Can. J. Zool. 66(11): 2329–2339) is presented. Although McArdle presented both linear and multiple linear regression models, we limit our comment to the linear model only. McArdle’s eq. 2 is corrected. Deming’s alternative form of the maximum likelihood (ML) solution (Deming 1943; Statistical adjustment of data. John Wiley and Sons, Inc., New York) is introduced. In the ML solution, the ratio of the mean measurement variances of the y and x variables is assumed constant over the range of the data. However, when λMLis not constant, then iteratively reweighted generalized Deming regression or functional relationship estimation by maximum likelihood is more appropriate.

Biodiversity in urban habitat patches

We examined the biodiversity of urban habitats in Birmingham (England) using a combination of field surveys of plants and carabid beetles, genetic studies of four species of butterflies, modelling the anthropochorous nature of the floral communities and spatially explicit modelling of selected mammal species. The aim of the project was to: (i) understand the ecological characteristics of the biota of cities model, (ii) examine the effects of habitat fragment size and connectivity upon the ecological diversity and individual species distributions, (iii) predict biodiversity in cities, and (iv) analyse the extent to which the flora and fauna utilise the 'urban greenways' both as wildlife corridors and as habitats in their own right. The results suggest that cities provide habitats for rich and diverse range of plants and animals, which occur sometimes in unlikely recombinant communities. The studies on carabids and butterflies illustrated the relative importance of habitat quality on individual sites as opposed to site location within the conurbation. This suggests that dispersal for most of our urban species is not a limiting factor in population persistence, although elements of the woodland carabid fauna did appear to have some geographical structuring. Theoretical models suggested that dormice and water voles may depend on linear habitats for dispersal. The models also indicated that other groups, such as small and medium sized mammals, may use corridors, although field-based research did not provide any evidence to suggest that plants or invertebrates use urban greenways for dispersal. This finding indicates the importance of identifying a target species or group of species for urban greenways intended as dispersal routeways rather than as habitat in their own right. Their importance for most groups is rather that greenways provide a chain of different habitats permeating the urban environment. We suggest that planners can have a positive impact on urban biodiversity by slowing the pace of redevelopment and by not hurrying to tidy up and redevelop brownfield sites.

Fatty Acid Profiles Associated with Microbial Colonization of Freshly Ingested Grass and Rumen Biohydrogenation

Two in situ studies were conducted to examine the use of odd-chain fatty acid profiles to study microbial colonization of freshly ingested herbage in the rumen as well as fatty acid biohydrogenation. In the first study, fresh perennial ryegrass was subjected to a range of sample preparation methods before incubation in the rumen for 2 or 7 h. In the second study, fresh perennial ryegrass was chopped into 1-cm lengths and incubated in polyester bags in the rumen for 2, 8, and 24 h. After removal of bags from the rumen, 4 different washing methods, ranging from manual squeezing to machine washing, were applied. Fatty acids were extracted from washed residues and determined, as methyl esters, by gas chromatography. The main odd-chain fatty acids (with the exception of anteiso C(15:0)) were not found in fresh grass and were useful markers of the effects of incubation time, sample preparation method, and washing method on microbial colonization/contamination. The concentration of these and other odd-chain fatty acids increased with incubation time in both studies. The results indicate rapid and continued microbial colonization of freshly ingested forages, although patterns of odd-chain fatty acids did not reveal any further information about the types of bacteria-colonizing herbage. Principal component, biplot analysis provided a useful overall description of the processes of microbial colonization and degradation of plant fatty acids on fresh herbage incubated in the rumen. Bolus formation during mastication and ingestion results in extensive damage to herbage; none of the techniques (cutting, crushing, and drying/grinding) investigated in this work was able to replicate the effects of bolus formation in the animal. The study provided further evidence of loss of unfermented feed particles through polyester bag pores, especially when feeds are dried and ground. Biohydrogenation of the polyunsaturated fatty acids of fresh herbage was used principally by solid-associated bacteria to enable them to take up high levels of trans-11 C(18:1) and C(18:0) fatty acids. Although trans-11 C(18:1) was strongly associated with bacterial markers (odd- and branched-chain fatty acids), its precursor (cis-9, trans-11 C(18:2)) was not associated with bacterial variation, suggesting that its production in the rumen under these conditions was mainly extracellular.

Photoproduction of eta-mesic 3He

The photoproduction of eta-mesic 3He has been investigated using the TAPS calorimeter at the Mainz Microtron accelerator facility MAMI. The total inclusive cross section for the reaction gamma3He-->etaX has been measured for photon energies from threshold to 820 MeV. The total and angular differential coherent eta cross sections have been extracted up to energies of 745 MeV. A resonancelike structure just above the eta production threshold with an isotropic angular distribution suggests the existence of a resonant quasibound state. This is supported by studies of a competing decay channel of such a quasibound eta-mesic nucleus into pi(0)pX. A binding energy of (-4.4+/-4.2) MeV and a width of (25.6+/-6.1) MeV is deduced for the quasibound eta-mesic state in 3He.

Technical note: A proposed method to determine the extent of degradation of a feed in the rumen from the degradation profile obtained with the in vitro gas production technique using feces as the inoculum1

A method is proposed to determine the extent of degradation in the rumen involving a two-stage mathematical modeling process. In the first stage, a statistical model shifts (or maps) the gas accumulation profile obtained using a fecal inoculum to a ruminal gas profile. Then, a kinetic model determines the extent of degradation in the rumen from the shifted profile. The kinetic model is presented as a generalized mathematical function, allowing any one of a number of alternative equation forms to be selected. This method might allow the gas production technique to become an approach for determining extent of degradation in the rumen, decreasing the need for surgically modified animals while still maintaining the link with the animal. Further research is needed before the proposed methodology can be used as a standard method across a range of feeds.

The reaction gammap-->pi0gamma'p and the magnetic dipole moment of the Delta+ 1232 resonance

The reaction gammap-->pi(0)gamma'p has been measured with the TAPS calorimeter at the Mainz Microtron accelerator facility MAMI for energies between sqrt[s]=1221-1331 MeV. The cross section's differential in angle and energy have been determined for the photon gamma' in three bins of the excitation energy. This reaction channel provides access to the magnetic dipole moment of the Delta(+)(1232) resonance and, for the first time, a value of mu(Delta(+))=[2.7(+1.0)(-1.3)(stat)+/-1.5(syst)+/-3(theor)]mu(N) has been extracted.

In-medium modifications of the pipi interaction in photon-induced reactions

Differential cross sections of the reactions (gamma,pi(0)pi(0)) and (gamma,pi(0)pi(+/-)) have been measured for several nuclei (1H,12C, and (nat)Pb) at an incident-photon energy of E(gamma)=400-460 MeV at the tagged-photon facility at MAMI-B using the TAPS spectrometer. A significant nuclear-mass dependence of the pipi invariant-mass distribution is found in the pi(0)pi(0) channel. This dependence is not observed in the pi(0)pi(+/-) channel and is consistent with an in-medium modification of the pipi interaction in the I=J=0 channel. The data are compared to pi-induced measurements and to calculations within a chiral-unitary approach.

Functional results following pharyngolaryngooesophagectomy with free jejunal graft reconstruction

OBJECTIVE

A free jejunal graft is used for reconstruction following pharyngolaryngooesophagectomy, due to the relative ease of harvesting, low donor site morbidity and a lumen diameter compatible with that of the oesophagus. Our aim is to evaluate the postoperative outcome and functional results of the procedure.

METHODS

Retrospective analysis of 20 consecutive patients, with a mean age of 62.5 years (range 48--76), who underwent free jejunal reconstruction following pharyngolaryngooesophagectomy for laryngeal malignancy. Surgery was performed secondary to radiotherapy or as the main stem of treatment. The functional results were assessed at 6 months and 1 year and correlated with postoperative morbidity. Chi-square test was used for statistical significance and Kaplan--Meyer to estimate survival.

RESULTS

There were six transient leaks and six cases with anastomotic stricture. There was no morbidity associated with the donor site and the perioperative mortality (30 days) was zero. At 6 months, 13 (87%) out of the 15 patients alive had satisfactory speech and 11 (78%) had satisfactory swallowing. At 1 year, 11 patients were alive and maintained a satisfactory speech, while nine (81%) of them were eating well. The incidence of leaks, strictures, or the moment of radiotherapy has no influence on the functional outcome. The 1- and 3-year survival rates were 52.3 and 33.2%, respectively.

CONCLUSIONS

A free jejunal graft reconstruction is technically demanding, but provides a near-physiologic swallowing mechanism, avoiding the complications of a gastric pull-up procedure. Functional results are good and justify the procedure despite the relatively high co-morbidity.

Acantholysis and spongiosis are associated with loss of syndecan-1 expression

BACKGROUND

Syndecan-1, a heparan sulfate proteoglycan present on the membrane of keratinocytes, functions in intercellular adhesion. Acantholysis and spongiosis are both characterized by diminished intercellular adhesion that may lead to blister formation. In spongiotic conditions, desmosomal stretching occurs prior to cell separation while in acantholytic conditions, cell separation occurs without stretching. While many of the structural relationships have been described, the molecular interactions regulating keratinocyte to keratinocyte adhesion are not yet fully understood.

METHODS

Sections from ten cases of Grover's disease, two pemphigus vulgaris, one pemphigus foliaceus, one bullous pemphigoid, two herpes simplex, and ten spongiotic dermatitis were stained with BB-4, a monoclonal anti-syndecan-1 antibody.

RESULTS

Nine of ten Grover's, all three pemphigus, and both herpes cases showed absent or markedly decreased syndecan-1 expression by acantholytic keratinocytes, with a sharp delineation from adjacent unaffected skin. The remaining Grover's case showed moderate loss of syndecan-1 expression. The pemphigus foliaceus case showed retention of staining along the basal cell layer, but expression was lost in the mid stratum spinosum. All ten spongiotic cases showed a diffuse mild decrease in staining, with loss of syndecan-1 expression surrounding microvesicles. Bullous pemphigoid, as expected, did not show loss of syndecan expression.

CONCLUSIONS

The loss of syndecan-1 expression evident in acantholytic conditions and, to a lesser extent in spongiotic conditions, may contribute to the decreased intercellular adhesion characteristic of these lesions.

Variation in the probability of cardiac complications with radiation technique in early breast cancer

Cardiac damage is recognized to be a potentially serious side effect of breast cancer radiotherapy, the risk of which may be reduced by the choice of appropriate radiotherapy technique. We have previously described variation in physical dose to the heart dependent upon radiotherapy technique. In this paper we report the calculated improvement in normal tissue complication probability (NTCP) (for cardiac damage) achievable by these methods. Cardiac doses were calculated from dose-volume histograms (DVHs) using a "Helax" planning system for 11 patients with left-sided tumours and 5 patients with right-sided tumours. The DVH reduction algorithm of Lyman and Wolbarst [1989] was applied to each DVH to produce a value for the NTCP. For left-sided tumours, mean NTCP with the standard technique was 7.4 +/- 5.6% (range 0.6-17%) and for the optimum technique mean NTCP was 0.3 +/- 0.6% (range 0-2%) (p < 0.003 for the difference between the two techniques): a predicted reduction in late cardiac complications of 23-fold, which is not clearly evident from viewing the DVH raw data.

Comparison of Pulmicort pMDI plus Nebuhaler and Pulmicort Turbuhaler in asthmatic patients with dysphonia

BACKGROUND

Dysphonia is a known local adverse effect of inhaled corticosteroids. This symptom was investigated by laryngoscopy and assessment in a voice laboratory. The effects of changing the treatment of patients with dysphonia, reported whilst using the pMDI, to pMDI plus Nebuhaler or Tubuhaler was also assessed.

METHODS

Seventy-two patients reporting dysphonia and taking inhaled steroids from a pMDI entered a 12-week, open, parallel group study. Fifty-one completed the study per protocol; 26 in the Nebuhaler group [21 female, mean age 57 years (22-77)] and 25 in the Turbuhaler group [18 female, mean age 58 years (21-81)]. A dysphonia diary card was completed weekly. Voice laboratory assessments and laryngoscopy were performed on entry and at 12 weeks.

RESULTS

There were no differences in voice laboratory data, laryngoscopic evidence of disordered glottic closure and diary data between the two groups at 12 weeks. At study entry laryngoscopic appearances were normal in almost half the patients. Vocal cord bowing was rarely seen. Glottic closure changed in nine patients during the study period, but there was no correlation with voice symptoms. The trend of symptomatic improvement of voice status in the Turbuhaler group did not correlate with voice laboratory assessments and laryngoscopic evidence of disordered glottic closure. After 4 weeks, 40% of patients using Turbuhaler and 8% in the Nebuhaler group scored their voice status as better (P < 0.02) but there was no significant difference between the two groups at 12 weeks (Turbuhaler 52%, Nebuhaler 23%, P=0.08).

CONCLUSION

This study does not support the view that dysphonia in asthmatics inhaling corticosteroids is usually caused by myopathic bowing of the vocal cord muscles.

Estimating the extent of degradation of ruminant feeds from a description of their gas production profiles observed in vitro: comparison of models

An evaluation of general models that describe gas production profiles is presented. The models are derived from first principles by considering a simple three-pool scheme and permit the extent of ruminal degradation to be calculated, as described in the companion paper. The models evaluated were the generalized Mitscherlich, simple Mitscherlich, generalized Michaelis-Menten, simple Michaelis-Menten, Gompertz, and logistic. Five sets of gas production data consisting of 216 curves, obtained using a wide range of feeds (including straw, hay, silage, grain and various byproducts), were analysed to study the performance of these gas production models. Application of the non-sigmoidal models (simple Mitscherlich and Michaelis-Menten) to the data resulted in convergence problems and these models were found to be inadequate in many cases. Based on results of a pairwise comparison between models (variance ratio test), ranking of residual mean squares, lack-of-fit test, and of analyses of residuals, the generalized Mitscherlich and the generalized Michaelis-Menten models seemed particularly suited because of their flexibility to encompass sigmoidal and non-sigmoidal shapes of gas production profiles, whether symmetrical or not.

Lung uptake of thallium-201: a marker of defect reversibility?

High lung uptake of thallium-201 at stress is reported to be associated with a large number of perfusion defects and poor prognosis. This study was performed to assess whether the reversibility of stress perfusion defects was related to lung uptake. Gated planar thallium scans at stress and at redistribution from 102 consecutive patients with essentially normal left ventricular ejection fraction (using 99mTc gated blood pool ventriculography) were graded in terms of defect size. Lung and myocardial uptake of thallium were quantitated by region of interest methods relative to the given activity in a previously validated method. There was no significant correlation (non-parametric) between lung uptake and degree of redistribution (p = ns, rs = 0.140). There was a weak but positive correlation between lung uptake and defect size (p < 0.05, rs = 0.188). Both exercise time and double product showed a negative correlation with lung uptake (e.g. for double product, p < 0.0005, rs = -0.541). In conclusion, contrary to our expectation, lung uptake is not related to the degree of redistribution. High lung uptake seems to reflect poor cardiovascular reserve.

Coding mutations in p57KIP2 are present in some cases of Beckwith-Wiedemann syndrome but are rare or absent in Wilms tumors

The Beckwith-Wiedemann syndrome (BWS) is marked by fetal organ overgrowth and conveys a predisposition to certain childhood tumors, including Wilms tumor (WT). The genetics of BWS have implicated a gene that maps to chromosome 11p15 and is paternally imprinted, and the gene encoding the cyclin-cdk inhibitor p57KIP2 has been a strong candidate. By complete sequencing of the coding exons and intron/exon junctions, we found a maternally transmitted coding mutation in the cdk-inhibitor domain of the KIP2 gene in one of five cases of BWS. The BWS mutation was an in-frame three-amino-acid deletion that significantly reduced but did not fully abrogate growth-suppressive activity in a transfection assay. In contrast, no somatic coding mutations in KIP2 were found in a set of 12 primary WTs enriched for cases that expressed KIP2 mRNA, including cases with and without 11p15.5 loss of heterozygosity. Two other 11p15.5 loci, the linked and oppositely imprinted H19 and IGF2 genes, have been previously implicated in WT pathogenesis, and several of the tumors with persistent KIP2 mRNA expression and absence of KIP2 coding mutations showed full inactivation of H19. These data suggest that KIP2 is a BWS gene but that it is not uniquely equivalent to the 11p15.5 "WT2" tumor-suppressor locus.

Air contamination following aerosol ventilation in the gamma camera room

Air contamination levels arising from lung aerosol ventilation studies have previously been monitored [1]. Residence time in the room used for ventilation was perceived to be an important factor in dose received. This study was designed to assess air contamination levels when ventilation and imaging are carried out in the same room. Air samples were taken before, during and after aerosol administration, over 24 studies where a mouthpiece was used. The mean airborne contamination during administration was 4.39 kBq m-3, implying an effective dose equivalent (EDE) to the operator from inhaled activity of 0.004 microSv. Measurements made during studies on three patients where a mask was used gave a mean EDE of 0.065 microSv (the highest EDE was 0.08 microSv). Ten minutes after nebulizing had stopped, the contamination had reduced to background levels in all but two cases; in these cases, the levels were less than 1.1 kBq m-3. Aerosol ventilation in the gamma camera room does not constitute a significant radiation hazard to staff. Patient compliance is an important factor in minimizing doses. Clear instructions and practice are a vital part of the procedure.

Breast irradiation in the older woman: a toxicity study

OBJECTIVE

To establish the tolerance of breast irradiation by women aged 65 and older.

DESIGN

Retrospective chart review.

PATIENTS AND SETTING

Women undergoing partial mastectomy and postoperative radiation therapy at the H. Lee Moffitt Cancer Center and Research Institute between 1986 and 1990. Of 163 women eligible for the study, 100 were under age 65, and 63 were aged 65-78.

MEASUREMENTS

Comparison of total treatment dose, treatment duration, number of treatment interruptions, incidence of cutaneous, mucosal, and hematological toxicity between women aged 65 and older and women younger than age 65.

MAIN RESULTS

All study measurements were comparable among younger and older women: total radiation dose (P = 0.5); treatment interruptions (P = 0.063); treatment duration (P = 0.78); cutaneous toxicity (P = 0.37); anemia (P = 0.83); leukopenia (P = 0.07), and thrombocytopenia (P = 0.94). There was no mucosal toxicity, nor higher than grade 2 hematological or cutaneous toxicity. The incidence and severity of toxicity was not higher for women aged 70 and older.

CONCLUSIONS

Postoperative breast irradiation is well tolerated by older women. Age is not a contraindication to breast preservation.

Cost-effectiveness of white cell-reduction filters in treatment of adult acute myelogenous leukemia

The objective of this study was to compare the cost and cost-effectiveness of three transfusion strategies in the treatment of acute myelogenous leukemia: 1) the use of unfiltered pooled platelets until alloimmunization developed and of crossmatch-compatible single-donor platelets thereafter; 2) the use of filtered blood components until alloimmunization occurred and of crossmatch-compatible single-donor platelets thereafter; and 3) the use of single-donor platelets from the beginning. The data sources were English language articles on transfusion medicine in acute leukemia and the management of acute leukemia and review of the transfusion experience at the H. Lee Moffitt Cancer Center. The method was decision analysis with a software program for cost-effectiveness, sensitivity analysis, threshold evaluation, and Monte Carlo sensitivity analysis. In the basic models, the total costs of the first, second, and third strategies are, respectively, $12,557.14, $11,406.17, and $13,016.16 without bone marrow transplant and $14,002.72, $12,281.89, and $13,727.48 with bone marrow transplant. The threshold between the first and second strategies in regard to risk of refractoriness to filtered blood components and pooled platelets was 0.30 and 0.27, respectively, without bone marrow transplant and 0.28 and 0.40 with bone marrow transplant. According to a Monte Carlo sensitivity analysis of 500 samples, the second strategy is more cost-effective than the first in 76 percent of cases. It is concluded that the use of filtered blood components is unlikely to increase the cost of treatment.

Immunocytochemical localization of endopeptidase-24.11 in the nucleus tractus solitarius of the rat brain

Recently, it has been hypothesized that the N-terminal portion of substance P (SP), SP(1-7), which results from the action of endopeptidase 24.11 (EC3.4.24.11), could be involved in mediating the depressor effects of baroreceptor afferent activation via its action on cells in the nucleus tractus solitarius (NTS). In this study, the binding of a monoclonal antibody to endopeptidase 24.11 was examined immunohistochemically at the level of the caudal medulla of the rat brain. By light microscopy, intense immunoreactivity was seen in the NTS, in fibers bordering the area postrema, and in the area postrema itself. After electron microscopy, endopeptidase 24.11-like immunoreactivity was seen to be associated with the cytoskeleton and plasma membrane in axons, dendrites and glial processes. Antigen was also associated with synaptic vesicles and plasma membranes in presynaptic terminals forming mainly axo-dendritic synapses typical of vagal afferent terminals involved in the baroreceptor reflex. Thus, endopeptidase 24.11 appears to be localized at sites where it could effectively process SP prior to its binding to postsynaptic receptors.

Transverse traction in the treatment of scoliosis. A preliminary report

Nineteen scoliotic patients were treated with the standard Harrington distraction rod supplemented with transverse traction. The latter consists of a compressive device (either Harrington';s or Cotrel's) applied to the convex side of the curve to correct disc space wedging and then drawn toward the distraction rod with a simple traction apparatus. Intraoperative roentgenograms were taken with the Harrington distraction rod alone after maximal distraction was applied. This was followed by postoperative roentgenograms with the transverse traction added. The 50.3% correction by distraction rod alone is increased to 66% with the addition of transverse traction. Detailed analysis of each curve, segment by segment, showed that the correction was augmented, not only in the center of the curve, where the compression corrected disc space wedging, but in the ends of the curve as well. This series uses each patient as his or her own control in demonstrating increased correction added by transverse traction.