A231 UNDERSTANDING THE IMPACT OF TNF-ALPHA ANTAGONISTS ON THE SEVERITY OF NON-MELANOMA SKIN CANCER IN INFLAMMATORY BOWEL DISEASE AND THE CONSEQUENCES FOR THERAPY

Background

Non-melanoma skin cancer (NMSC) accounts for at least 40% of all new cancer diagnoses in Canada annually and presents a significant cost to the health care system due to the volume of cases. The incidence of NMSC in patients with Inflammatory Bowel Disease (IBD) is higher when compared to the general population. Generally, in a non-IBD population, the risk of further NMSC progression is low, however, little data exists that highlights differences in clinical course of patients diagnosed with NMSC who have IBD and are TNF-α antagonist exposed. It is unclear if TNF-α antagonist therapy should be discontinued in this patient population.

Aims

Our goal is to determine whether TNF-α antagonist exposure in IBD is associated with a high risk NMSC presentation at diagnosis, as defined by the National Comprehensive Cancer Network (NCCN) stratification. Our secondary objectives include presence of positive margins following resection, presence of metastatic disease on initial presentation, requirement of additional therapy to treat NMSC, number of patients who had TNF-α antagonist therapy discontinued following diagnosis of NMSC and number of individuals with recurrent NMSC.

Methods

Four hundred and twenty-four IBD patients seen at London Health Sciences Centre were reviewed. We have identified 22 patients who were diagnosed with NMSC. Twelve patients had a pre-NMSC TNF-α antagonist exposure while 10 patients who developed an NMSC and had no TNF-α antagonist exposure prior to NMSC diagnosis.

Results

Preliminary results of the primary outcome demonstrate that fifty-percent (6/12) of patients who have been exposed to TNF antagonist therapy presented with a high risk NMSC lesion at diagnosis compared to 40% (4/10) who were not exposed (OR 5.16, 95%CI 0.47–57.00; p = 0.181). Preliminary results of the secondary outcomes suggest that 25% (3/12) of patients exposed to TNF-α antagonist had positive margins compared with 0% (0/10) of patients who were not exposed. No patients in either group presented with metastatic disease. Twenty-five percent (3/12) of patients in the exposed group received more advanced treatment compared with 0% (0/10) in the non-exposed group. Eight percent (1/12) of patients in the TNF-α antagonist group had their IBD therapy changed from a TNF-α antagonist to an alternative biologic class, and 17% of patients (2/12) in the TNF-α antagonist group had recurrent NMSC lesions.

Conclusions

In conclusion, preliminary results suggest that TNF-α antagonist exposure may be associated with higher risk NMSC lesion at presentation. Further expansion of the sample size is required to explore these hypotheses further.

Funding Agencies

None

A254 IGA-MEDIATED WARM AUTOIMMUNE HEMOLYTIC ANEMIA IN A PATIENT WITH CROHN’S DISEASE ON VEDOLIZUMAB

Background

Iron deficiency anemia and anemia of chronic disease are relatively common manifestations of Crohn’s disease. Autoimmune hemolytic anemia, however, is quite rare with few reported cases.

Aims

To present a rare case of IgA-mediated warm autoimmune hemolytic anemia in Crohn’s Disease.

Methods

A chart review and literature search were performed in preparation of this case report.

Results

A 21-year-old male with a recent diagnosis of Crohn’s disease on Vedolizumab presents to infusion clinic with generalized weakness, coke-colored urine and weight loss. Physical examination was remarkable for tachycardia and jaundice. Laboratory investigations revealed profound anemia with IgA-mediated DAT positivity. The patient remained admitted in hospital for a prolonged period. Bone marrow biopsy, CT imaging and infectious workup were negative. Vedolizumab was held and treatment with both high-dose corticosteroids and rituximab was required. Eventually, the anemia would stabilize and Vedolizumab was safely resumed as an outpatient.

Conclusions

Here we report a both rare and challenging case of IgA-mediated DAT positive autoimmune hemolytic anemia in a patient with Crohn’s disease who was successfully treated with corticosteroids and rituxumab.

Funding Agencies

None

Pentoxifylline Does Not Influence Maximum Ultrafiltration Rates and Peritoneal Transport in Rats

Previous publications have suggested that peritoneal capillary blood flow and filtration pressure equilibrium may limit ultrafiltration rates with very hypertonic exchanges. Rats were treated with pentoxifylline, which decreases blood viscosity by increasing red blood cell deformability. Decreases in blood viscosity should reduce microcirculatory resistance and increase effective capillary flow. Transport studies were performed after 2, 4, and 8 weeks of therapy with peritoneal dialysis solutions containing 15 grams % dextrose and using 30-min cycles. Even though rats ingested near the maximum recommended dose of pentoxifylline (20 mg/kg) significant changes in blood viscosity and shear stress were not detected compared to controls. Also, there were no significant differences in clearances of urea and phosphorus, glucose absorption, protein losses, and net ultrafiltration compared to controls.

P41 Correlation of doppler ultrasound assessment of carotid femoral pulse wave velocity with coronary artery disease

Funding Acknowledgements

self

Background

Arterial stiffness is an important cardiovascular risk factor. Carotid femoral pulse wave velocity (cfPWV) is simple noninvasive  method to determine aortic stiffness. Arterial stiffness measures, cfPWV in particular,  have been found to be correlate with stroke and peripheral artery disease. Usually SphygmoCor or Complior are used to calculate cfPWV. Doppler ultrasound can serve as an alternative to these methods. 

Purpose

To assess cfPWV using doppler ultrasound and study its correlation with coronary artery disease and its severity. 

Methods

cfPWV was assessed by ultrasound Doppler in patient aged 20-70 years undergoing coronary angiography.  cfPWV was measured by sequential recordings of arterial pressure waveform at the carotid and femoral arteries with a Doppler ultrasound with ECG gating and calculated as the distance between the carotid and the femoral sampling site divided by the time interval. 

Result

Of the 358 subjects studied, 243 had coronary artery disease(CAD) (>50% diameter stenosis) and were further divided into single, double or triple vessel disease groups. 115 patients  had mild CAD (< 50% stenosis) or no CAD and served as controls. Baseline characteristics were similar except diabetes (more common in CAD group)(39.09% v/s 27.82%). cfPWV was found to increase with age in all groups. cfPWV was not significantly affected  by sex, diabetes, dyslipidemia, BMI, smoking or hypothyroidism. Mean cfPWV was significantly higher in patients with CAD (8.99 v/s 6.51 m/s, p < 0.001) and hypertensives (8.71 v/s 7.83 m/s, p < 0.001). Patients with triple vessel disease(TVD) had significantly higher cfPWV (10.12 m/s) than those with double(DVD)(8.84 m/s) or single vessel disease(SVD)(8.28m/s)(p < 0.001). Multinomial logistic regression revealed an odds ratio of 2.00, 2.375 and 3.368 respectively for SVD, DVD and TVD groups in comparison to controls (p < 0.001). cfPWV value > 7.25 m/s predicted CAD with sensitivity 78.6 % and specificity 74.8% (AUC =0.848, P < 0.001). 

Conclusion

Carotid femoral pulse wave velocity can be measured noninvasively by ultrasound Doppler. cfPWV increases with age and hypertension and has strong correlation with coronary artery disease and its severity. The cfPWV can be an independent risk factor and may be utilized for cardiovascular risk prediction.

Abstract P41 Figure. cfPWV in various subgroups.

Comorbidities in Mycosis Fungoides and Racial Differences in Co-Existent Lymphomatoid Papulosis: A Cross-Sectional Study of 580 Patients in an Urban Tertiary Care Center

Background: Mycosis fungoides (MF) is a cutaneous T-cell lymphoma. Previous reports have suggested MF is associated with inflammatory conditions such as psoriasis, increased cardiovascular risk factors as well as secondary neoplasms. Methods: A cross-sectional study of MF patients seen from 2013 to 2019 was performed. Comorbidities were selected based on the 2015 Medicare report highlighting the most common chronic medical illnesses in the United States. Lifetime comorbidity occurrence in patients with MF were compared with that in patients with atopic dermatitis, psoriasis and patients without MF. Additional analyses were performed with patients sub-stratified by race. Results: Compared to control groups, MF was strongly associated with lymphomatoid papulosis and Hodgkin's disease, but not significantly associated with lung, breast or colon cancer. Interestingly, the association with lymphomatoid papulosis was observed in Caucasians (CI 1062-4338; p < 0.001) and not African Americans (p = 0.9). Patients with MF had a greater association with congestive heart failure, hypertension (HT) and hyperlipidemia (HLD) compared with the general population. However, they were significantly less likely to have HT and HLD when compared with psoriasis patients (HT CI: 0.6-0.9; p < 0.001, and HLD CI: 0.05-0.07; p < 0.001). MF patients were also significantly less likely to have concomitant vitamin D deficiency compared with atopic dermatitis (AD) and psoriasis (p < 0.001). Conclusions: Our results suggest that the association of MF with lymphomatoid papulosis varies by race. Compared to the general population, hypertension and hyperlipidemia were positively associated with MF, however, these were significantly less likely on comparison to psoriasis. Unlike previously described, vitamin D deficiency was found to be significantly less in patients with MF.

Proteomic and Phosphoproteomic Analysis Reveals that Neurokinin-1 Receptor (NK1R) Blockade with Aprepitant in Human Keratinocytes Activates a Distinct Subdomain of EGFR Signaling: Implications for the Anti-Pruritic Activity of NK1R Antagonists

Background: Epidermal growth factor receptor (EGFR) inhibitors can cause serious cutaneous toxicities, including pruritus and papulopustular acneiform skin eruptions. Increasingly, the neurokinin-1 receptor (NK1R) antagonist aprepitant is being utilized as an anti-pruritic agent in the treatment of EGFR-inhibitor induced pruritus. Aprepitant is believed to reduce itching by blocking NK1R on the surface of dermal mast cells. However, the effects of aprepitant on human keratinocytes remains unexplored. Methods: Herein, we examine the effects of aprepitant on EGFR stimulation in HaCaT cells using a phosphoproteomic approach including reverse phase protein arrays and Ingenuity Pathway Analysis. Changes in EGFR phosphorylation were visualized using Western blotting and the effect of EGF and aprepitant on the growth of HaCaT cells was determined using the WST-1 Cell Proliferation Assay System. Results: We found that aprepitant increased the phosphorylation of EGFR, as well as 10 of the 23 intracellular proteins phosphorylated by EGF. Analysis of phosphoproteomic data using Ingenuity Pathway Analysis software revealed that 5 of the top 10 pathways activated by EGF and aprepitant are shared. Conclusions: We propose that aprepitant produces its antipruritic effects by partially activating EGFR. Activation of EGFR by aprepitant was also seen in primary human keratinocytes. In addition to itch reduction through partial activation of shared EGFR pathways, aprepitant exerts a dose-dependent cytotoxicity to epithelial cells, which may contribute to its antitumor effects.

P1496Use of strain, strain rate, tissue velocity imaging and endothelial function for early detection of cardiovascular involvement in young diabetics

Background

Subtle structural and functional changes may precede the onset of overt global left ventricular dysfunction and obvious reduction of ejection fraction (EF), especially in young diabetics. Data pertaining to tissue velocity indices (TVI) and strain imaging to assess regional myocardial function and flow mediated vasodilatation is limited in young patients with diabetes.

Purpose

To evaluate conventional echocardiography parameters, tissue doppler indices, global and regional strain, carotid intimal medial thickness (CIMT), endothelial dependent (FMD) and independent function (NMD) of brachial artery in young patients (age <18 years) with type 1 diabetes and compare them with matched controls.

Methods

Conventional echocardiography parameters, tissue velocity indices (TVI) parameters along with strain (S), and strain rate (SR) in basal and mid left ventricular (LV) lateral wall, right ventricular (RV) lateral wall and septum were measured in 50 young diabetics (age 15.16±2.95 years, mean HBA1c 8.15±1.37 gm %) and 25 controls (age 15.60±2.51 years). Flow-mediated dilatation (FMD), nitrate mediated dilatation and carotid intimal media thickness (CIMT) were also estimated.

Results

Conventional echocardiography parameters were similar in patients and controls however deceleration time of the mitral inflow velocity (EDT) was significantly shorter in patients when compared with controls (149.06±31.66 vs. 184.56±19.27 ms, p<0.05). Lateral early diastolic myocardial velocity (LV-Em) was significantly lower (10.30±0.99 vs. 11.67±3.21, p<0.05) whereas lateral late diastolic myocardial velocity (LV-Am) was significantly higher than controls (11.73±1.44 vs. 8.82±1.69, p<0.05), thus a significantly lower ratio of early/late diastolic velocity at the basal segment of lateral LV (LV-Em/Am). Lower strain values at the basal lateral LV (21.39±4.12 vs. 23.78±2.02; p<0.05), mid lateral LV (21.43±4.27 vs. 23.17±1.92; p<0.05), basal septum (20.59±5.28 vs. 22.91±2.00; p<0.05), and mid septum (22.06±4.75 vs. 24.10±1.99; p<0.05) as compared to controls. SR at the basal and mid segments of the lateral LV wall and at the basal septum were also significantly lower in diabetic subjects. Strain rate (SR) in mid septal, basal and mid RV were lower than controls although not statistically significant. Patients also had significantly lower flow mediated dilatation (FMD) (8.36±4.27 vs. 10.57±4.12, p<0.05) implying endothelial dysfunction.

Strain rate in diabetic patient

Conclusion

Left ventricular strain indices are impaired in asymptomatic children and adolescents with type 1 DM despite absence of overt heart failure and normal ejection fraction. Early detection of subclinical regional myocardial dysfunction by deformation analysis including strain and strain rate may be useful in the asymptomatic diabetic population. In addition, evidence of endothelial dysfunction in the form of impaired flow mediated vasodilatation was observed in the diabetic children.

Acknowledgement/Funding

None

Racial differences in dermatologic conditions associated with HIV: A cross-sectional study of 4679 patients in an urban tertiary care center

BACKGROUND

Because of reduced mortality, patients with HIV are living longer and presenting with chronic diseases. Little is known about racial differences in dermatologic conditions associated with HIV infection.

OBJECTIVE

This study examines associated dermatologic conditions in a large population of patients with HIV at a tertiary care center with a diverse patient population.

METHODS

Cross-sectional study of patients with HIV seen between July 14, 2013, and July 14, 2018, in a tertiary health care system. The burden of HIV-related dermatologic conditions was collected by using medical records. Patients with HIV were compared with control individuals of the same race, and significance was assessed using the chi-square test. A Bonferroni correction was performed to control for multiple hypothesis testing.

RESULTS

The study population (N = 4679) was 64.7% male and 69% African American, with 88.7% of patients receiving antiretroviral therapy. African American patients with HIV had a greater risk of oral hairy leukoplakia (odds ratio [OR], 64.49), herpes zoster (OR, 9.27), prurigo nodularis (OR, 8.80), and squamous cell carcinoma (OR, 5.72).

LIMITATIONS

Our data describe patients seen by 1 health care system.

CONCLUSIONS

African American patients with HIV may be at increased risk for pruritic disorders compared with race-matched control individuals and white patients with HIV.

Genetic and pharmacological antagonism of NK1 receptor prevents opiate abuse potential

Development of an efficacious, non-addicting analgesic has been challenging. Discovery of novel mechanisms underlying addiction may present a solution. Here we target the neurokinin system, which is involved in both pain and addiction. Morphine exerts its rewarding actions, at least in part, by inhibiting GABAergic input onto substance P (SP) neurons in the ventral tegmental area (VTA), subsequently increasing SP release onto dopaminergic neurons. Genome editing of the neurokinin 1 receptor (NK1R) in the VTA renders morphine non-rewarding. Complementing our genetic approach, we demonstrate utility of a bivalent pharmacophore with dual activity as a μ/δ opioid agonist and NK1R antagonist in inhibiting nociception in an animal model of acute pain while lacking any positive reinforcement. These data indicate that dual targeting of the dopaminergic reward circuitry and pain pathways with a multifunctional opioid agonist-NK1R antagonist may be an efficacious strategy in developing future analgesics that lack abuse potential.

Concentration of rare earth elements during high temperature pyrolysis of waste printed circuit boards

An in-depth investigation was carried out on the recovery of rare earth elements (REEs) from a variety of waste printed circuit boards (PCBs). High temperature pyrolysis was carried out at 850 °C for 15 min using horizontal resistance and thermal plasma furnaces with different levels of turbulence. The concentration of REEs in key pyrolysis residues, namely, copper rich red metallic fraction, lead/tin rich white metallic fraction and slag rich carbonaceous residues, were determined using ICP analysis. Most of the REEs were found concentrated in the carbonaceous residue with negligible levels of REEs recovered in the two metallic fractions. Most of the recovered REEs showed a high affinity towards to refractory oxides silica and alumina, and little affinity towards metals Cu, Pb and Sn. The yield of REEs was significantly higher from the plasma furnace indicating the important role of turbulence in the dissociation & subsequent diffusion of REEs during pyrolysis. While La, Pr, Sm and Y required turbulent conditions for their recovery, Nd, Gd, Ce and Dy were relatively easy to dissociate and extract from the waste. Significant amounts of REEs could thus be recovered from waste PCBs as concentrated recyclates for further processing and extraction of individual rare earths. This study has shown that PCBs could prove to be a valuable urban mining resource of REEs. The recovery of REEs, in addition to precious and other metals, could play an important role towards enhancing the economic and environmental sustainability of e-waste recycling.

Diet and dermatology: Google search results for acne, psoriasis, and eczema

It is difficult to regulate the abundance of medical information that is available to patients on the Internet. This systematic review evaluated content available online related to diet and 3 dermatologic conditions: acne, psoriasis, and eczema. Ultimately, our results indicated that most of the information that can be found online regarding diet and these dermatologic conditions is unfounded and/or misleading. Although current medical research may support some Internet findings, it is important to advise patients that many results of online searches for medical conditions are unconfirmed.

Radiomic biomarkers informative of cancerous transformation in neurofibromatosis-1 plexiform tumors

BACKGROUND

This study explores whether objective, quantitative radiomic biomarkers derived from magnetic resonance (MR), positron emission tomography (PET), and computed tomography (CT) may be useful in reliably distinguishing malignant peripheral nerve sheath tumors (MPNST) from benign plexiform neurofibromas (PN).

METHODS

A registration and segmentation pipeline was established using a cohort of NF1 patients with histopathological diagnosis of PN or MPNST, and medical imaging of the PN including MR and PET-CT. The corrected MR datasets were registered to the corresponding PET-CT via landmark-based registration. PET standard-uptake value (SUV) thresholds were used to guide segmentation of volumes of interest: MPNST-associated PET-hot regions (SUV≥3.5) and PN-associated PET-elevated regions (2.0<SUV<3.5). Quantitative imaging features were extracted from the MR, PET, and CT data and compared for statistical differences. Intensity histogram features included (mean, media, maximum, variance, full width at half maximum, entropy, kurtosis, and skewness), while image texture was quantified using Law's texture energy measures, grey-level co-occurrence matrices, and neighborhood grey-tone difference matrices.

RESULTS

For each of the 20 NF1 subjects, a total of 320 features were extracted from the image data. Feature reduction and statistical testing identified 9 independent radiomic biomarkers from the MR data (4 intensity and 5 texture) and 4 PET (2 intensity and 2 texture) were different between the PET-hot versus PET-elevated volumes of interest.

CONCLUSIONS

Our data suggests imaging features can be used to distinguish malignancy in NF1-realted tumors, which could improve MPNST risk assessment and positively impact clinical management of NF1 patients.

Systematic review with meta-analysis: endoscopic and histologic placebo rates in induction and maintenance trials of ulcerative colitis

BACKGROUND

Regulatory requirements for claims of mucosal healing in ulcerative colitis (UC) will require demonstration of both endoscopic and histologic healing. Quantifying these rates is essential for future drug development.

AIMS

To meta-analyse endoscopic and histologic placebo response and remission rates in UC randomised controlled trials (RCTs) and identify factors influencing these rates.

METHODS

MEDLINE, EMBASE and the Cochrane Library were searched from inception to March 2017 for placebo-controlled trials of pharmacological interventions for UC. Endoscopic and histologic placebo rates were pooled by random effects. Mixed effects univariable and multivariable meta-regression was used to evaluate the influence of patient, intervention and trial-related study-level covariates on these rates.

RESULTS

Fifty-six induction (placebo n = 4171) and 8 maintenance trials (placebo n = 1011) were included. Pooled placebo endoscopic remission and response rates for induction trials were 23% [95 confidence interval (CI) 19-28%] and 35% [95% CI 27-42%] respectively, and 20% [95% CI 16-24%] for maintenance of remission. The pooled histologic placebo remission rate was 14% [95% CI 8-22%] for induction trials. High heterogeneity was observed for all outcomes (I² 56.2%-88.3%). On multivariable meta-regression, central endoscopy reading was associated with significantly lower endoscopic placebo remission rates (16% vs 25%; OR = 0.52, [95% CI 0.29-0.92], P = 0.03). On univariable meta-regression, higher histologic placebo remission was associated with concomitant corticosteroids (OR = 1.17 [95% CI 1.08-1.26], P < 0.0001, per 10% increase in corticosteroid use).

CONCLUSIONS

Placebo endoscopic and histologic rates range from 14% to 35% in UC RCTs but are highly heterogeneous. Outcome standardisation may reduce heterogeneity and is needed in this field.

Characterization of L-Histidine Ammonia-lyase Immobilized by Microencapsulation in Artificial Cells: Preparation, Kinetics, Stability, and in Vitro Depletion of Histidine

L-histidine ammonia-lyase (histidase) was encapsulated within cellulose nitrate artificial cells, and its kinetic parameters were evaluated. Microencapsulated histidase had an apparent activity of histidase in solution. Encapsulation did not alter the Km of histidase. The Km of histidase solution and the Km apparent of micro-encapsulated histidase were both 20mM. Encapsulation of histidase resulted in increased stability of enzymatic activity at storage temperatures of 4°C and 37°C. At 37°C histidase solution reached 50% of its original activity after 9.5 days of storage, while microencapsulated histidase reached the same level after 15 days. At 4°C histidase solution had 63% of its original activity after 21 days of storage, while encapsulated histidase had 95%. In vitro experiments to evaluate the feasibility of microencapsulated histidase for possible experimental therapy in histidinemia were carried out. These experiments evaluated the effectiveness of encapsulated histidase in depleting histidine. Three different volume ratios of histidase loaded artificial cells to substrate solution were tested. A ratio of 1: 100 allowed 25% histidine depletion after 120 hours. A 1: 50 ratio allowed 35% histidine depletion after 72 hours. A 1: 25 ratio allowed 40% histidine depletion after 24 hours.

Total Creatine Kinase and Isoenzyme Fractions in Chronic Dialysis Patients

We measured total serum creatine kinase (CK) and serum creatine kinase MB fraction (CK-MB) in 53 patients on continuous ambulatory peritoneal dialysis (CAPD) and 52 patients on maintenance hemodialysis (HD), using Scalva UV methodology for CK and electrophoresis for CK-MB. Seven of the 53 CAPD patients (13%) had an elevated total CK, and only one of these 7 patients had an elevated CK-MB > 5%. In contrast 22 HD patients (42%) had increased total CK values, and 6 of these 22 HD patients (27%) showed elevated CK-MB isoenzyme > 5%. For each sex, blacks had higher mean CK values than whites. Twenty-one out of the 43 HD patients who received intramuscular injections had elevated total CK values and 6 of these 21 patients had elevated CK-MB isoenzyme independent of the timing of injection. The increased frequency of higher total CK values in HD patients appears to be related to race and androgen administration. The modest elevations in CK-MB fraction (5 to 8%) in these patients require careful interpretation.

Osmotic Agents for Peritoneal Dialysis

Glucose has more advantages than drawbacks and is now the sole agent used in clinical practice. Yet there is interest in finding a substitute for glucose as an osmotic agent in peritoneal dialysis solution. Work has identified several promising agents such as albumin, amino acids, gelatin and glycerol but it appears that every one of them, including glucose, would be useful for a short-dwell or for a long-dwell exchange but not for both. Some of them, such as albumin and the amino acids, are close to being an ideal osmotic agent but are prohibitively costly to manufacture. We predict that interest in the future will focus on dialysis solutions containing a mixture of osmotic agents. Such a solution would be acceptable for both short and long-dwell exchanges. It will have a sufficiently low concentration of different agents to minimize toxicity and long-term undesirable side effects. We expect that solutions will be available to better meet patients needs in the near future.

High temperature investigations on optimising the recovery of copper from waste printed circuit boards

High temperature pyrolysis investigations were carried out on waste printed circuit boards (PCBs) in the temperature range 800-1000°C under inert conditions, with an aim to determine optimal operating conditions for the recovery of copper. Pyrolysis residues were characterized using ICP-OES analysis, SEM/EDS and XRD investigations. Copper foils were successfully recovered after pyrolysis at 800°C for 10-20 min; the levels of Pb and Sn present were found to be quite low and these were generally present near the foil edges. The relative proportions of Pb and Sn became progressively higher at longer heating times due to enhanced diffusion of these molten metals in solid copper. While a similar behaviour was observed at 900°C, the pyrolysis at 1000°C resulted in copper forming Cu-Sn-Pb alloys; copper foils could no longer be recovered. Optimal conditions were identified for the direct recovery of copper from waste PCBs with minimal processing. This approach is expected to make significant contributions towards enhancing material recovery, process efficiency and the environmental sustainability of recycling e-waste. Pyrolysis at lower temperatures, short heating times, coupled with reductions in process steps are expected to significantly reduce energy consumption and pollution associated with the handling and processing of waste PCBs.

HLA-DQA1-HLA-DRB1 polymorphism is a major predictor of azathioprine-induced pancreatitis in patients with inflammatory bowel disease

BACKGROUND

Azathioprine (AZA)-induced pancreatitis is an unpredictable and dose-independent adverse event affecting 2%-7% of patients with inflammatory bowel disease (IBD) patients treated with AZA. There are no tools in clinical practice to identify at-risk individuals; however, a genome wide association study (GWAS) identified a strong association between the Class II HLA gene region polymorphism (rs2647087) and thiopurine-induced pancreatitis.

AIM

To independently confirm the findings of the GWAS in an IBD cohort, to evaluate its utility in clinical practice and to offer a novel AZA treatment algorithm for IBD based on pharmacogenomic principles.

METHODS

A retrospective cohort study evaluated 373 AZA-exposed IBD patients from a tertiary care academic centre in London, Canada. Due to the limited number of patients taking mercaptopurine (MP), such patients were not included this cohort. All subjects underwent screening for the single nucleotide polymorphism (SNP) rs2647087 mapped to the HLA-DQA1*02:01-HLA-DRB1*07:01 haplotype and were sub-divided based on the presence (n = 13) or absence (n = 360) of an AZA-induced pancreatitis diagnosis. The risk of AZA-induced pancreatitis was assessed based on rs2647087 genotype.

RESULTS

The risk of pancreatitis during AZA-therapy was highly predictable and genotype dependent: 0.53% for wild type (A/A), 4.25% (OR = 4.19, 95% CI 1.02-36.45, P = 0.044) for heterozygous (A/C), and 14.63% (OR = 15.83, 95% CI 3.80-145.26, P = 0.0001) for homozygous variant (C/C) patients.

CONCLUSIONS

The class II HLA region (at rs2647087) is an important marker of AZA-induced pancreatitis risk. We propose a simple and clinically implementable algorithm based on rs2647087 and TPMT genotypes for AZA selection and dosing for patients with IBD.