Differential Immune Responses in Epidemic and Endemic Tanzanian Kaposi Sarcoma Patients

Background: Mechanisms underlying Kaposi sarcoma (KS) development are unclear. The high incidence of KS in HIV-1+ individuals implicates immune dysregulation in epidemic KS (EpKS) development. In African endemic KS (EnKS), the immune response is uncharacterized. Aim: The aim was to assess a comparative quantification between newly diagnosed Tanzanian EpKS and EnKS patients, and asymptomatic controls. We also report the first comparison of KSHV NAb prevalence and titer between EpKS and EnKS patients. Methods: To compare innate and adaptive immune responses, we recruited histologically confirmed Tanzanian EpKS and EnKS patients, as well as noncancer controls. After differential detection of KSHV nucleic acids in tissues, neutralizing antibody (NAb), levels of cytokines/chemokines, and T-cell differentiation subsets were quantified. The Mann-Whitney U-test was used to assess median differences between groups. All tests were 2-tailed and P-values < 0.05 were considered significant. Results: A total of 180 patients have been recruited in this study. In addition, a comparable 25 EpKS and 10 EnKS as well as 10 noncancer controls were recruited for this study. KSHV was significantly more frequently detected in EpKS patients than in EnKS. While all EpKS, and some EnKS patients mounted NAb responses, the EpKS patients had higher prevalence and titer of NAb compared with EnKS patients ( P = 0.001). Levels of the cytokines IP-10 and IL-10 were higher in EpKS vs EnKS patients ( P = 0.006 and P = 0.005 respectively), whereas, IL-4 was lower in EpKS vs EnKS patients ( P = 0.004). The levels of all 14 cytokines/chemokines measured were comparable between EnKS patients and HIV− controls ( P < .05 ). The distribution of CD4+ and CD8+ T-cells was similar between EpKS and EnKS such as naive and effector T-cells were depleted while central memory T-cells were elevated in both KS forms. Conclusion: The detection of similar abnormalities in T-cell differentiation subsets in both EpKS and EnKS as compared with controls, suggests that KSHV-induced T-cell dysfunction plays a major role in the disease, and that HIV-1 coinfection is only exacerbating and accelerating KSHV pathogenesis and KS development.

Narrowband ultraviolet B treatment for psoriasis is highly economical and causes significant savings in cost for topical treatments

BACKGROUND

Narrowband ultraviolet B (NB-UVB) treatment for psoriasis is considered expensive. However, existing data are based on estimates and do not consider indirect cost savings.

OBJECTIVES

To define the actual costs of NB-UVB incurred by the service provider, as well as treatment-associated cost savings.

METHODS

We performed data linkage of (i) comprehensive treatment records and (ii) prescribing data for all NB-UVB treatment episodes spanning 6 years in a population of 420 000. We minimized data fluctuation by compiling data from four independent treatment sites, and using drug prescriptions unrelated to psoriasis as a negative control.

RESULTS

National Health Service Tayside spent an average of £257 per NB-UVB treatment course (mean 257 ± 63, range 150-286, across four independent treatment sites), contrasting sharply with the estimate of £1882 used by the U.K. National Institute for Health and Care Excellence. The cost of topical treatments averaged £128 per patient in the 12 months prior to NB-UVB, accounting for 42% of the overall drug costs incurred by these patients. This was reduced by 40% to £53 per patient over the 12-month period following NB-UVB treatment, while psoriasis-unrelated drug prescription remained unchanged, suggesting disease-specific effects of NB-UVB. The data were not due to site-specific factors, as confirmed by highly similar results observed between treatment sites operated by distinct staff. Finally, we detail all staff hours directly and indirectly involved in treatment, allowing direct translation of cost into other healthcare systems.

CONCLUSIONS

NB-UVB is a low-cost treatment; cost figures currently used in health technology appraisals are an overestimate based on the data presented here. Creating or extending access to NB-UVB is likely to offer additional savings by delaying or avoiding costly third-line treatments for many patients.

Meta-analysis of operative experiences of general surgery trainees during training

BACKGROUND

General surgical training curricula around the world set defined operative numbers to be achieved before completion of training. However, there are few studies reporting total operative experience in training. This systematic review aimed to quantify the published global operative experience at completion of training in general surgery.

METHODS

Electronic databases were searched systematically for articles in any language relating to operative experience in trainees completing postgraduate general surgical training. Two reviewers independently assessed citations for inclusion using agreed criteria. Studies were assessed for quantitative data in addition to study design and purpose. A meta-analysis was performed using a random-effects model of studies with appropriate data.

RESULTS

The search resulted in 1979 titles for review. Of these, 24 studies were eligible for inclusion in the review and data from five studies were used in the meta-analysis. Studies with published data of operative experience at completion of surgical training originated from the USA (19), UK (2), the Netherlands (1), Spain (1) and Thailand (1). Mean total operative experience in training varied from 783 procedures in Thailand to 1915 in the UK. Meta-analysis produced a mean pooled estimate of 1366 (95 per cent c.i. 1026 to 1707) procedures per trainee at completion of training. There was marked heterogeneity between studies (I²  = 99·6 per cent).

CONCLUSION

There is a lack of robust data describing the operative experiences of general surgical trainees outside the USA. The number of surgical procedures performed by general surgeons in training varies considerably across the world.

Risk of hepatocellular carcinoma among individuals with different aetiologies of cirrhosis: a population-based cohort study

BACKGROUND

Among patients with cirrhosis, only those determined to be at risk for hepatocellular carcinoma (HCC) should undergo surveillance. However, little is known about how different aetiologies of cirrhosis affect risk for HCC.

AIM

To quantify the cumulative incidence of HCC among a representative population of people with cirrhosis of the liver of varying aetiology.

METHODS

We identified subjects with hepatic cirrhosis from the UK's General Practice Research Database (1987-2006). Diagnoses of HCC were obtained from linked national cancer registries (1971-2006). Cox proportional hazards regression was used to estimate hazard ratios. The predicted 10-year cumulative incidence of HCC for each aetiology of cirrhosis was estimated while accounting for competing risks of death from any cause and liver transplant.

RESULTS

Among 3107 people with cirrhosis, the adjusted relative risk of HCC was increased twofold to threefold among people with viral and autoimmune/metabolic aetiologies, compared to those with alcohol-associated cirrhosis. The 10-year predicted cumulative incidence estimates of HCC for each aetiology were alcohol, 1.2%; chronic viral hepatitis, 4.0%; autoimmune or metabolic disease, 3.2%; and cryptogenic, 1.1%.

CONCLUSIONS

In a population-based study in the UK, people with cirrhosis have an estimated cumulative 10-year incidence of HCC of 4% or lower. Cumulative incidence varies with aetiology such that individuals with alcohol or cryptogenic cirrhosis have the lowest risk for HCC. These findings provide important information for cost-effectiveness analyses of HCC surveillance.

The risk of community-acquired pneumonia among 9803 patients with coeliac disease compared to the general population: a cohort study

BACKGROUND

Patients with coeliac disease are considered as individuals for whom pneumococcal vaccination is advocated.

AIM

To quantify the risk of community-acquired pneumonia among patients with coeliac disease, assessing whether vaccination against streptococcal pneumonia modified this risk.

METHODS

We identified all patients with coeliac disease within the Clinical Practice Research Datalink linked with English Hospital Episodes Statistics between April 1997 and March 2011 and up to 10 controls per patient with coeliac disease frequency matched in 10-year age bands. Absolute rates of community-acquired pneumonia were calculated for patients with coeliac disease compared to controls stratified by vaccination status and time of diagnosis using Cox regression in terms of adjusted hazard ratios (HR).

RESULTS

Among 9803 patients with coeliac disease and 101 755 controls, respectively, there were 179 and 1864 first community-acquired pneumonia events. Overall absolute rate of pneumonia was similar in patients with coeliac disease and controls: 3.42 and 3.12 per 1000 person-years respectively (HR 1.07, 95% CI 0.91-1.24). However, we found a 28% increased risk of pneumonia in coeliac disease unvaccinated subjects compared to unvaccinated controls (HR 1.28, 95% CI 1.02-1.60). This increased risk was limited to those younger than 65, was highest around the time of diagnosis and was maintained for more than 5 years after diagnosis. Only 26.6% underwent vaccination after their coeliac disease diagnosis.

CONCLUSIONS

Unvaccinated patients with coeliac disease under the age of 65 have an excess risk of community-acquired pneumonia that was not found in vaccinated patients with coeliac disease. As only a minority of patients with coeliac disease are being vaccinated there is a missed opportunity to intervene to protect these patients from pneumonia.

ID: 113: THE ENDOTHELIAL PHD2/HIF-2 AXIS REGULATES PULMONARY ARTERY PRESSURE IN MICE

Background

Pulmonary hypertension (PH), a common clinical problem characterized by increased pulmonary artery (PA) pressure, is frequently triggered by hypoxia. Key mediators of cellular hypoxia responses are hypoxia-inducible factors (HIF)-1 and -2, the activity of which is regulated by prolyl-4-hydroxylase domain (PHD) proteins, with PHD2 being the main oxygen sensor that controls HIF activity under normoxia. Although both transcription factors are expressed in the lung, little is known about their cell type-specific roles in the pathogenesis of PH.

Methods and Results

Here we used a genetic approach to investigate the role of endothelial PHD2/HIF axis in the regulation of PA pressure. Endothelial cell specific HIF activation was achieved by crossing Vecadherin (Cdh5)-Cre transgenics to Phd2 floxed mice (ePhd2), while the contribution of each HIF isoform was assessed by generating double mutants lacking Phd2 and Hif-2 (ePhd2Hif2) or Phd2 and Hif-1 (Phd2Hif1). Right ventricular systolic pressure (RVSP) was measured via insertion of a 1.4F Mikro-tip catheter transducer into a surgically exposed right internal jugular vein. ePhd2 mice showed activation of HIF-signaling as shown by immunoblot analysis of lung tissue for HIF-1 and HIF-2. These mice developed spontaneous PH (RVSP, ePhd2: 54.3±6.9 vs Cre-: 24.8±2.2 mm Hg, P=0.005), which was associated with right ventricular hypertrophy (RVH) (Fulton Index, ePhd2: 0.52 vs Cre-: 0.28, P=0.0004) and early mortality. While morphologic analysis of ePhd2 lungs did not demonstrate plexiform or lumen-obliterating lesions, enhanced muscularization of peripheral PAs was detected in mutants compared to controls, as indicated by an increase in the number of arteries with diameters <100 µm that stained positive for αSMA (22.1±1.6 vs. 7.6±1.5 muscularized vessels/10 hpf, P<0.0001). The PH phenotype was maintained in ePhd2Hif1 mutants but was reversed in ePhd2Hif2 mutants. To assess the contribution of endothelial HIF-2 in hypoxia induced PH, endothelial Hif2 single mutants or Cre-littermates were exposed to normobaric hypoxia (10% O2) for 4 weeks. In contrast to controls, eHif2 mutants were protected from development of PH and RVH. Bone marrow transplantation studies showed no contribution from hematopoietic HIF-2 in hypoxia induced PH. Because hypoxia regulates endothelin 1 (EDN1), a potent vasoconstrictor but also apelin (APLN), a vasodilatory peptide acting through binding to the apelin G-protein-coupled receptor (APLNR), we assessed the role of endothelial HIF-2 axis in the regulation of these molecules. Endothelial deletion of Phd2 resulted in 6.4-fold induction of pulmonary Edn1 mRNA (P=0.029), but not Apln mRNA. In contrast, Aplnr was downregulated by 2.5-fold in ePhd2 mutants (P=0.037). A similar pattern of expression was detected in ePhd2Hif1 mice, whereas simultaneous deletion of Hif2a and Phd2 reversed these changes. To investigate the differences between acute and chronic hypoxia, we examined the effects of acute HIF activation on Edn1 and Apln/Aplnr gene expression in vivo. To model acute hypoxia, we subjected WT mice to 8% O2 for 48 hrs and maintained controls in room air. Acute hypoxia resulted in a 4.3-fold and 1.6-fold up-regulation of Edn1 and Apln transcripts respectively (P=0.0011 for Edn1, P=0.08 for Apln) while Aplnr was reduced by 4.3-fold (P=0.0005). We observed similar gene expression changes in mice treated with a prolyl-4-hydroxylase inhibitor (PHI) that results in global HIF activation.

Conclusions

Our studies identify endothelial HIF-2 as a key transcription factor in the pathogenesis of PH and suggest that HIF-2 regulates PA pressure by modulating the expression of vasoactive molecules. Our findings identify the PHD2/HIF2 axis as a potential target for PH therapies.

Risk of symptomatic venous thromboembolism following emergency appendicectomy in adults

Background

Appendicectomy is the commonest intra-abdominal emergency surgical procedure, and little is known regarding the magnitude and timing of the risk of venous thromboembolism (VTE) after surgery. This study aimed to determine absolute and relative rates of symptomatic VTE following emergency appendicectomy.

Methods

A cohort study was undertaken using linked primary (Clinical Practice Research Datalink) and secondary (Hospital Episode Statistics) care data of patients who had undergone emergency appendicectomy from 2001 to 2011. Crude rates and adjusted incidence rate ratios (IRRs) for VTE were calculated using Poisson regression, compared with baseline risk in the year before appendicectomy.

Results

A total of 13 441 patients were identified, of whom 56 (0·4 per cent) had a VTE in the first year after surgery. The absolute rate of VTE was highest during the in-hospital period, with a rate of 91·29 per 1000 person-years, which was greatest in those with a length of stay of 7 days or more (267·12 per 1000 person-years). This risk remained high after discharge, with a 19·1- and 6·6-fold increased risk of VTE in the first and second months respectively after discharge, compared with the year before appendicectomy (adjusted IRR: month 1, 19·09 (95 per cent c.i. 9·56 to 38·12); month 2, 6·56 (2·62 to 16·44)).

Conclusion

The risk of symptomatic VTE following appendicectomy is relatively high during the in-hospital admission and remains increased after discharge. Trials of extended thromboprophylaxis are warranted in patients at particularly high risk.

Designing environmental research for impact

Transdisciplinary research, involving close collaboration between researchers and the users of research, has been a feature of environmental problem solving for several decades, often spurred by the need to find negotiated outcomes to intractable problems. In 2005, the Australian government allocated funding to its environment portfolio for public good research, which resulted in consecutive four-year programmes (Commonwealth Environmental Research Facilities, National Environmental Research Program). In April 2014, representatives of the funders, researchers and research users associated with these programmes met to reflect on eight years of experience with these collaborative research models. This structured reflection concluded that successful multi-institutional transdisciplinary research is necessarily a joint enterprise between funding agencies, researchers and the end users of research. The design and governance of research programmes need to explicitly recognise shared accountabilities among the participants, while respecting the different perspectives of each group. Experience shows that traditional incentive systems for academic researchers, current trends in public sector management, and loose organisation of many end users, work against sustained transdisciplinary research on intractable problems, which require continuity and adaptive learning by all three parties. The likelihood of research influencing and improving environmental policy and management is maximised when researchers, funders and research users have shared goals; there is sufficient continuity of personnel to build trust and sustain dialogue throughout the research process from issue scoping to application of findings; and there is sufficient flexibility in the funding, structure and operation of transdisciplinary research initiatives to enable the enterprise to assimilate and respond to new knowledge and situations.