Efficient and safe therapeutic use of paired Cas9-nickases for primary hyperoxaluria type 1

The therapeutic use of adeno-associated viral vector (AAV)-mediated gene disruption using CRISPR-Cas9 is limited by potential off-target modifications and the risk of uncontrolled integration of vector genomes into CRISPR-mediated double-strand breaks. To address these concerns, we explored the use of AAV-delivered paired Staphylococcus aureus nickases (D10ASaCas9) to target the Hao1 gene for the treatment of primary hyperoxaluria type 1 (PH1). Our study demonstrated effective Hao1 gene disruption, a significant decrease in glycolate oxidase expression, and a therapeutic effect in PH1 mice. The assessment of undesired genetic modifications through CIRCLE-seq and CAST-Seq analyses revealed neither off-target activity nor chromosomal translocations. Importantly, the use of paired-D10ASaCas9 resulted in a significant reduction in AAV integration at the target site compared to SaCas9 nuclease. In addition, our study highlights the limitations of current analytical tools in characterizing modifications introduced by paired D10ASaCas9, necessitating the development of a custom pipeline for more accurate characterization. These results describe a positive advance towards a safe and effective potential long-term treatment for PH1 patients.

Sulfur Interaction and Regeneration of CaMn0.775Ti0.125Mg0.1O2.9-δ Perovskite as Oxygen Carrier during Combustion of Sour Gas in a 500 Wth Chemical Looping Combustion Unit

In the present study, the performance of a CaMn0.775Ti0.125Mg0.1O2.9-δ perovskite used as an oxygen carrier to burn sour gas with different H2S concentrations (up to 3000 vppm) in a continuous 500 Wth chemical looping combustion (CLC) prototype was investigated. After 29 h of sour gas combustion, the combustion efficiency had dropped by 18% in comparison with the reference test without sulfur addition. The characterization of the used particles of the perovskite confirmed that the presence of sulfur in the fuel gas had a poisonous effect through the formation of undesired compounds, such as CaSO4. The reactivity with CH4 and oxygen uncoupling capacity decreased, which could explain the decrease in the combustion efficiency. Two regeneration processes, one at high temperature (1273 K) and another one at low temperature (773-873 K), were carried out in a batch fluidized bed reactor to remove the amount of sulfur accumulated in the oxygen carrier particles. The detection of appreciable amounts of gaseous sulfur-based compounds (SO2 and H2S) during the experimentation and the postcharacterization results obtained through different techniques such as X-ray diffraction, ultimate analysis, and thermogravimetric analysis confirmed the effectiveness of both processes. Finally, the feasibility of implementation of the regeneration processes in a commercial CLC unit was thoroughly analyzed.

Tomography of irregular rough particles using the error-reduction algorithm with multi-views interferometric particle imaging

This work reports the 3D reconstruction of a particle from a set of three simulated interferometric images of this particle (from three perpendicular angles of view). The reconstruction of each view from its corresponding interferometric pattern uses the error-reduction (ER) algorithm. The 3D reconstruction enables an estimation of the volume of the particle. The method is tested on a dendrite-like particle. An experimental demonstration of the technique is done using a digital micromirror device (DMD) that generates the interferometric images of "programmable" rough particles.

Analysis of copy number alterations reveals the lncRNA ALAL-1 as a regulator of lung cancer immune evasion

Cancer is characterized by genomic instability leading to deletion or amplification of oncogenes or tumor suppressors. However, most of the altered regions are devoid of known cancer drivers. Here, we identify lncRNAs frequently lost or amplified in cancer. Among them, we found amplified lncRNA associated with lung cancer-1 (ALAL-1) as frequently amplified in lung adenocarcinomas. ALAL-1 is also overexpressed in additional tumor types, such as lung squamous carcinoma. The RNA product of ALAL-1 is able to promote the proliferation and tumorigenicity of lung cancer cells. ALAL-1 is a TNFα- and NF-κB-induced cytoplasmic lncRNA that specifically interacts with SART3, regulating the subcellular localization of the protein deubiquitinase USP4 and, in turn, its function in the cell. Interestingly, ALAL-1 expression inversely correlates with the immune infiltration of lung squamous tumors, while tumors with ALAL-1 amplification show lower infiltration of several types of immune cells. We have thus unveiled a pro-oncogenic lncRNA that mediates cancer immune evasion, pointing to a new target for immune potentiation.

bsAS, an antisense long non-coding RNA, essential for correct wing development through regulation of blistered/DSRF isoform usage

Natural Antisense Transcripts (NATs) are long non-coding RNAs (lncRNAs) that overlap coding genes in the opposite strand. NATs roles have been related to gene regulation through different mechanisms, including post-transcriptional RNA processing. With the aim to identify NATs with potential regulatory function during fly development, we generated RNA-Seq data in Drosophila developing tissues and found bsAS, one of the most highly expressed lncRNAs in the fly wing. bsAS is antisense to bs/DSRF, a gene involved in wing development and neural processes. bsAS plays a crucial role in the tissue specific regulation of the expression of the bs/DSRF isoforms. This regulation is essential for the correct determination of cell fate during Drosophila development, as bsAS knockouts show highly aberrant phenotypes. Regulation of bs isoform usage by bsAS is mediated by specific physical interactions between the promoters of these two genes, which suggests a regulatory mechanism involving the collision of RNA polymerases transcribing in opposite directions. Evolutionary analysis suggests that bsAS NAT emerged simultaneously to the long-short isoform structure of bs, preceding the emergence of wings in insects.

The Jamaican Haemophilia Registry: Describing the burden of disease

INTRODUCTION

Jamaica has an estimated 200 persons with haemophilia (PWH), who face significant constraints in access to specialized haemophilia care, including access to clotting factor concentrates.

AIM

The aim of this paper is to establish the current burden of disease in PWH in Jamaica.

METHODS

PWH were enrolled through the University Hospital of the West Indies, Jamaica. The impact of haemophilia was assessed using a comprehensive battery of heath outcome measures that included the following: laboratory, clinical information and validated outcome measures of joint structure and function, activity, and health-related quality of life (HRQoL) to provide a health profile of the Jamaican haemophilia population.

RESULTS

In all, 45 PWH were registered (mean age: 29, range: 0.17-69 years), including 13 children (<18 years of age) and 32 adults. In this sample, 41 had haemophilia A (30 severe) and 4 had haemophilia B (3 severe); 10 patients with haemophilia A were inhibitor positive. The results indicate that adults with haemophilia in Jamaica have significant joint damage: mean Haemophilia Joint Health Score (HJHS) = 42.1 (SD = 17.3); moderate activity levels - mean Haemophilia Activities List (HAL) score = 64.8 (SD = 17.8); and low HRQoL scores - mean Haemo-QoL-A score = 62.3 (SD = 19.4). Results for children are also reported but should be interpreted with caution due to the small sample size.

CONCLUSIONS

There is a very high burden of disease in PWH in Jamaica. The health profiles reported in this paper are an essential first step in advocating for a multidisciplinary Comprehensive Care Program for assessment and care of PWH in Jamaica.

High-throughput annotation of full-length long noncoding RNAs with capture long-read sequencing

Accurate annotation of genes and their transcripts is a foundation of genomics, but currently no annotation technique combines throughput and accuracy. As a result, reference gene collections remain incomplete-many gene models are fragmentary, and thousands more remain uncataloged, particularly for long noncoding RNAs (lncRNAs). To accelerate lncRNA annotation, the GENCODE consortium has developed RNA Capture Long Seq (CLS), which combines targeted RNA capture with third-generation long-read sequencing. Here we present an experimental reannotation of the GENCODE intergenic lncRNA populations in matched human and mouse tissues that resulted in novel transcript models for 3,574 and 561 gene loci, respectively. CLS approximately doubled the annotated complexity of targeted loci, outperforming existing short-read techniques. Full-length transcript models produced by CLS enabled us to definitively characterize the genomic features of lncRNAs, including promoter and gene structure, and protein-coding potential. Thus, CLS removes a long-standing bottleneck in transcriptome annotation and generates manual-quality full-length transcript models at high-throughput scales.

Comparing the burden of illness of haemophilia between resource-constrained and unconstrained countries: the São Paulo-Toronto Hemophilia Study

INTRODUCTION

Although the regular replacement of clotting factor concentrates (prophylaxis) has been well established as the standard of care for severe haemophilia, the high cost of factor concentrates has limited access to prophylaxis in countries with under-developed or developing economies.

AIMS

We studied the health gap that could be addressed by providing unlimited access to clotting factor concentrates with implementation of long-term prophylaxis initiated from an early age in life.

METHODS

We performed a cross-sectional study of a random, representative sample of boys with moderate and severe haemophilia at three haemophilia treatment centres in Sao Paulo, Brazil, and one centre in Toronto, Canada.

RESULTS

Canadian subjects were more often treated with prophylaxis, and began treatment at an earlier age. Fewer Canadian subjects had bleeds within the preceding 6 months (19 vs. 34, P = 0.003). Canadian subjects had lower (better) Pettersson radiographic scores (1.5 vs. 6.0, P = 0.0016), lower (better) Hemophilia Joint Health Scores (5.5 vs. 10.5, P = 0.0038), higher (better) Activity Scale for Kids scores (96.6 vs. 92.0, P = 0.033), more time spent in vigorous activity, and higher (better) social participation scores.

CONCLUSIONS

Our findings suggest that increasing access to clotting factor concentrates for young boys with severe haemophilia is a global imperative.

Pilot study of once-a-day prophylaxis for youth and young adults with severe haemophilia A

INTRODUCTION

Standard prophylaxis has been shown to be an effective treatment for severe haemophilia A. According to pharmacokinetic principles, daily factor infusions of smaller doses can maintain similar trough factor VIII (FVIII) levels, and perhaps the same protection as standard prophylaxis.

AIM

This multicentre study examined the feasibility of daily prophylaxis for youth and young adults with severe haemophilia A in Montreal and Toronto.

METHODS

Bleeding rates, joint status, quality of life and physical activity were monitored for 14 patients during this study. At baseline, subjects continued their regular treatment regimen and switched to daily prophylaxis after 4 months; nine had begun daily prophylaxis before enrolment. Additional visits occurred at 8 and 12 months which included a physical examination, inhibitor testing, HJHS and FISH assessments, the CHO-KLAT/Haemo-QoL-A and PDPAR. Treatment satisfaction was assessed using the Treatment Satisfaction Questionnaire for Medication ver.II and perceived difficulty questions at the end of study.

RESULTS AND CONCLUSIONS

There were no significant changes in quality of life except for concerns with the demanding daily infusion schedule. The number of bleeds did not statistically differ from the initial 4 months of the study to the last 8 months. Monthly bleeding rates from the year prior to the study and during the intervention phase were not statistically different. It was also found that daily prophylaxis used 24% less FVIII compared to standard prophylaxis. Taking all of this into account, we have found that providing daily prophylaxis is feasible and that it is feasible to prospectively study daily prophylaxis in youth and young adults.

Validity of the Portuguese CHO-KLAT in Brazil

INTRODUCTION

It is essential to assess the health-related quality of life outcomes of boys with haemophilia in Brazil. The Canadian Haemophilia Outcomes-Kids Life Assessment Tool (CHO-KLAT) was recently adapted for this population.

AIM

To test the construct validity of the Portuguese version of the CHO-KLAT.

METHODS

We recruited 50 boys, with moderate [factor VIII (FVIII) level 1-5%] or severe (FVIII level <1%) haemophilia, to participate in a descriptive study to establish a baseline understanding of the current status of boys with haemophilia in Brazil. All boys were required to complete the Brazilian CHO-KLAT and Brazilian Pediatric Quality of Life Inventory (PedsQL) by self-report. We examined the correlation between the CHO-KLAT and PedsQL scores to establish the construct validity of the Brazilian version of the CHO-KLAT.

RESULTS

We obtained CHO-KLAT and PedsQL data from 35 boys with severe haemophilia and 15 with moderate haemophilia. They ranged in age from 7.3 to 18.0 years, with a mean of 13.0 years. They reported a mean CHO-KLAT score of 72.3 (range = 44.1-93.9). The mean PedsQL score was 79.9 (range = 45.7-96.7), with physical health (mean of 83.9) being better than psychosocial health (77.8). The Pearson's correlation between CHO-KLAT and PedsQL was 0.47 respectively (P < 0.001). The CHO-KLAT had a moderate and inverse relationship with the degree to which they were bothered by their haemophilia (ρ = -0.53), while the PedsQL had a weaker relationship (ρ = -0.27).

CONCLUSION

The results confirm the validity of the Portuguese version of the CHO-KLAT. This measure is now available for clinical trials in boys with haemophilia in Brazil.

Risk factors for accidents among cocaine-dependent patient seeking treatment

Introduction

Accident rate have a high social cost. Cocaine consumption increases the risk of traffic crashes (Monras, 2011; Fierro, 2011). However, there is not extensively studies in addicts.

Objective

Compare and analyze the history of accidents and risk behaviors while driving in cocaine dependent patients (DC) and of other substances (OtherD).

Methods

One hundred and eighty-two patients seeking treatment since January 2014 to September 2015. Sociodemographic and accident-related variables were collected, also administered the MDBQ. Descriptive analysis and bivariate analysis using Chi-square test for categorical variables and Student t test was performed for quantitative.

Results

Of women, 30.3%, and 69.7% men, mean age 43.67 years (SD = 13). 65.6% currently driving or above. 45.2% DC vs. 54.8 DOther (35.6% alcohol, cannabis 8.3%, 5.8% opioid and 5.1% other drugs).

Comparing accident rate on the DC is a tendency to have suffered more accidents (χ2: 2.62 P=.072). Patients addicted to cocaine referred further potentially dangerous activities both under the influence of consumption (65.9% vs. 33.3%) and abstinence (41.7% vs. 12%).

As for the results of MDBQ, it has been detected that cocaine addicts show more errors and traffic violations. No differences in the lapses identified by patients of different groups.

Conclusion

Patients with cocaine dependence have more accidents, reduced risk perception and recognize more mistakes and traffic violations. Cocaine implies a high risk of road accidents and exposure to high-risk situations compared to the use of other substances.

References not available.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Location of the sciatic nerve at the popliteal fossa in the adult population: Relationship with gender and anthropometric data studied. Implications for daily practice

OBJECTIVE

To determine whether the location of the sciatic nerve (SN) at the popliteal fossa is related to anthropometric variables in the adult population, and to identify possible anatomical variations and their possible implications for clinical practice.

MATERIALS AND METHOD

Prospective observational study in elective ambulatory surgery patients. Patients were examined using ultrasound, looking at depth, laterality and distance at which the SN bifurcates at the level of the popliteal fossa. These measurements were linked to gender and the anthropometric data of the patients.

RESULTS

A total of 62 patients were included, with 124 measurements. A statistically significant association was found between SN depth and the diameter of the thigh measured at 10 cm from the popliteal crease (P<.001). Mean depth: 3.32 ± 0.8 cm, mean laterality: 1.43 ± 0.9 cm, mean SN bifurcation distance: 61.78 ± 12 mm and mean SN diameter: 7.45 ± 1.17 mm. There were no statistical differences when comparing the measured variables with the age and gender. Similar results were obtained between measurements when comparing both lower limbs in the same patient. There was no statistical difference between height and distance at which the SN bifurcates.

CONCLUSIONS

The depth and laterality of SN are independent of gender, weight and height. The depth at which the SN is located at the level of the popliteal fossa is related to the diameter of the thigh. The bifurcation of SN in popliteal fossa is not related to height.

Breath methane in functional constipation: response to treatment with Ispaghula husk

BACKGROUND

Colonic fermentation produces hydrogen (H2 ), and also produces methane (CH4 ) in subjects with methanogenic flora (M+). Methane production has been associated with chronic constipation (CC) and with changes in gut motility. To determine CH4 production in CC compared to controls, and to assess whether the therapeutic response to Ispaghula husk in CC differs between CH4 -producers and non-producers.

METHODS

Forty-eight patients with functional constipation or irritable bowel syndrome-constipation and 19 healthy age-and-sex-matched volunteers (HV) filled in a 1-week symptom diary and a dietary questionnaire. They then underwent a lactulose breath test (LBT) to measure H2 and CH4 production (peak and area under the time-concentration curve, AUC-) and a colonic transit time (CTT) assessment. In patients, measurements were repeated after a 4-week treatment with Ispaghula husk.

KEY RESULTS

Prevalence of M+ in patients was 60.5% vs 52.6% in HV (p = 0.37). Patients had significantly longer CTT and greater production of both H2 and CH4 during LBT. There was a significant correlation between CH4 production and CTT (r = 0.51; p = 0.07). Treatment response rate was similar for M+ and M- patients (58.3% vs 52.9%; p = 0.76) as were the increases in bowel movements and Bristol score, changes in abdominal discomfort and bloating. In M+, treatment reduced CTT (-10 ± 35 h; p = 0.029 vs baseline) and CH4 levels: peak CH4 (-13 ± 24 ppm; p = 0.014) and CH4 -AUC (-817 ± 3100 ppm/min; p = 0.04).

CONCLUSIONS & INFERENCES

Although CH4 production has been associated with CC pathophysiology, we found that CH4 status did not negatively affect the response to Ispaghula husk treatment. The measurement of CH4 levels as a biomarker tool for CC requires further appraisal.

[Cost-effectiveness analysis of aflibercept in combination with FOLFIRI in the treatment of patients with metastatic colorectal cancer]

OBJECTIVES

To estimate the incremental cost per life-year gained (LYG) of aflibercept in combination with FOLFIRI as second-line treatment in metastatic colorectal cancer (mCRC) patients previously treated with oxaliplatin.

METHODS

Based on clinical trial VELOUR results, a three-state Markov model (stable disease, progression and death) with 2-week cycle duration was designed. Transition to health state «progression» implied the interruption of second-line treatment and administration of a third-line treatment (post-second line chemotherapy). Cost estimation included disease management cost (pharmaceutical, adverse event management, administration costs, etc.). Both cost and outcomes were discounted (3% annually). Sensitivity analyses (SA) were performed to test model robustness.

RESULTS

Administration of aflibercept + FOLFIRI as second-line treatment provided 1.78 LYG (21 life-months gained). With FOLFIRI 1.43 LYG (17 months) were obtained. The cost of the clinical management of aflibercept + FOLFIRI implied an additional investment of Euros 13,564 compared with FOLFIRI for a lifetime horizon, being total costs for aflibercept + FOLFIRI of Euros 38,346, compared to Euros 24,782 with FOLFIRI. In the cost-effectiveness analysis Euros 38,931/LYG was obtained with aflibercept in combination with FOLFIRI versus FOLFIRI.

CONCLUSION

Aflibercept in combination with FOLFIRI increased overall survival versus FOLFIRI, so it is an effective strategy in the treatment of patients with mCRC. Aflibercept in combination with FOLFIRI is an efficient strategy for second-line mCRC treatment from the National Health System perspective.

Increased in vivo inhibition of gene expression by combining RNA interference and U1 inhibition

Inhibition of gene expression can be achieved with RNA interference (RNAi) or U1 small nuclear RNA—snRNA—interference (U1i). U1i is based on U1 inhibitors (U1in), U1 snRNA molecules modified to inhibit polyadenylation of a target pre-mRNA. In culture, we have shown that the combination of RNAi and U1i results in stronger inhibition of reporter or endogenous genes than that obtained using either of the techniques alone. We have now used these techniques to inhibit gene expression in mice. We show that U1ins can induce strong inhibition of the expression of target genes in vivo. Furthermore, combining U1i and RNAi results in synergistic inhibitions also in mice. This is shown for the inhibition of hepatitis B virus (HBV) sequences or endogenous Notch1. Surprisingly, inhibition obtained by combining a U1in and a RNAi mediator is higher than that obtained by combining two U1ins or two RNAi mediators. Our results suggest that RNAi and U1i cooperate by unknown mechanisms to result in synergistic inhibitions. Analysis of toxicity and specificity indicates that expression of U1i inhibitors is safe. Therefore, we believe that the combination of RNAi and U1i will be a good option to block damaging endogenous genes, HBV and other infectious agents in vivo.

Joint health and functional ability in children with haemophilia who receive intensive replacement therapy

Joint physical examination is an important outcome in haemophilia; however its relationship with functional ability is not well established in children with intensive replacement therapy. Boys aged 4-16 years were recruited from two European and three North American treatment centres. Joint physical structure and function was measured with the Haemophilia Joint Health Score (HJHS) while functional ability was measured with the revised Childhood Health Assessment Questionnaire (CHAQ₃₈. Two haemophilia-specific domains were created by selecting items of the CHAQ₃₈ that cover haemophilia-specific problems. Associations between CHAQ, HJHS, cumulative number of haemarthroses and age were assessed. A total of 226 subjects - mean 10.8 years old (SD 3.8) - participated; the majority (68%) had severe haemophilia. Most severe patients (91%) were on prophylactic treatment. Lifetime number of haemarthroses [median=5; interquartile range (IQR)=1-12] and total HJHS (median = 5; IQR=1-12) correlated strongly (ρ = 0.51). Total HJHS did not correlate with age and only weakly (ρ=-0.19) with functional ability scores (median=0; IQR=-0.06-0). Overall, haemarthroses were reported most frequently in the ankles. Detailed analysis of ankle joint health scores revealed moderate associations (ρ=0.3-0.5) of strength, gait and atrophy with lower extremity tasks (e.g. stair climbing). In this population, HJHS summating six joints did not perform as well as individual joint scores, however, certain elements of ankle impairment, specifically muscle strength, atrophy and gait associated significantly with functional loss in lower extremity activities. Mild abnormalities in ankle assessment by HJHS may lead to functional loss. Therefore, ankle joints may warrant special attention in the follow up of these children.

Liver dysfunction related to hepatitis B and C in patients with inflammatory bowel disease treated with immunosuppressive therapy

BACKGROUND

There is no information about the frequency of liver dysfunction in patients with inflammatory bowel disease (IBD) treated with immunosuppressants and infected with hepatitis B (HBV) and/or C virus (HCV).

AIM

To assess the influence of immunosuppressants on the course of HBV and HCV infection in IBD.

METHODS

Patients with IBD with HBV and/or HCV infection from 19 Spanish hospitals were included. Clinical records were reviewed for the type of immunosuppressant used, treatment duration, liver function tests and viral markers before, during and after each immunosuppressant. Logistic and Cox regression analysis were used to identify predictors of outcome.

RESULTS

162 patients were included; 104 had HBV markers (25 HBsAg positive) and 74 had HCV markers (51 HCV-RNA positive), and 16 patients had markers of both infections. Liver dysfunction was observed in 9 of 25 HBsAg positive patients (36%), 6 of whom developed hepatic failure. Liver dysfunction in HCV was observed in 8 of 51 HCV-RNA positive patients (15.7%), and only one developed hepatic failure. The frequency and severity of liver dysfunction was significantly higher in HBV-infected patients than in HCV-infected patients (p=0.045 and p=0.049, respectively). Treatment with ≥2 immunosuppressants was an independent predictor of HBV reactivation (OR 8.75; 95% CI 1.16 to 65.66). The majority of patients without reactivation received only one immunosuppressant for a short period and/or prophylactic antiviral treatment. No definite HBV reactivations were found in anti-HBc positive patients lacking HBsAg.

CONCLUSION

Liver dysfunction in patients with IBD treated with immunosuppressants is more frequent and severe in those with HBV than in HCV carriers and is associated with combined immunosuppression.

Combination of RNA interference and U1 inhibition leads to increased inhibition of gene expression

RNA interference (RNAi) has been revolutionary for the specific inhibition of gene expression. However, the application of RNAi has been hampered by the fact that many siRNAs induce dose-dependent unwanted secondary effects. Therefore, new methods to increase inhibition of gene expression with low doses of inhibitors are required. We have tested the combination of RNAi and U1i (U1 small nuclear RNA—snRNA—interference). U1i is based on U1 inhibitors (U1in), U1 snRNA molecules modified to target a pre-mRNA and inhibit its gene expression by blocking nuclear polyadenylation. The combination of RNAi and U1i resulted in stronger inhibition of reporter or endogenous genes than that obtained using either of the techniques alone. The increased inhibition observed is stable over time and allows higher inhibition than the best obtained with either of the inhibitors alone even with decreased doses of the inhibitors. We believe that the combination of RNAi and U1i will be of interest when higher inhibition is required or when potent inhibitors are not available. Also, the combination of these techniques would allow functional inhibition with a decreased dose of inhibitors, avoiding toxicity due to dose-dependent unwanted effects.

Consensus on the treatment of pancreatic cancer in Spain

Pancreatic cancer (PC) represents one of the greatest oncological challenges of our century, due to its high mortality and incidence. A group of Spanish experts in PC treatment reviewed data available on different therapeutic combinations and established consensus on what would be the best strategy in PC management, depending on the stage of the disease. Surgery with complete resection may produce 5-year survival rates of 18-24%, but definitive control is still precarious. In the absence of consensus, the best evidence suggests that adjuvant chemotherapy with gemcitabine for 6 months using the CONKO-001 regime is the treatment of choice after resection of PC for patients with acceptable functional status. This group recommends chemoradiotherapy (CT-RT) in patients with factors for poor loco-regional prognosis. However, chemotherapy is an option for the treatment of locally advanced PC in patients with good general status and in the absence of metastatic disease the recommended treatment is CT-RT followed by gemcitabine-based chemotherapy. A period of chemotherapy followed by consolidation CT-RT may be appropriate, as it allows selection of patients with locally advanced disease who may benefit most from combined treatment. Erlotinib combined with gemcitabine shows significant survival improvement in PC and must be considered an option in the first-line treatment of advanced and metastatic PC. The gemcitabine-erlotinib combination is proposed as the standard treatment for metastatic PC in patients with PS=/>2. In patients with PS<2, gemcitabine-erlotinib is recommended as the first-line treatment option, supported by a maximum degree of evidence, without ruling out other options, such as gemcitabine-oxaliplatin, gemcitabine-capecitabine or gemcitabine alone.

Pharmacogenetic analysis of TS and UGT1A polymorphisms predictive for response and toxicity in Spanish patients with advanced colorectal cancer treated with first-line irinotecan and 5-fluorouracil

4066

Background: The possible role of uridine diphosphate-glucuronosyltransferase 1A (UGT1A) and Thymidylate Synthase (TS) gene polymorphisms in predicting toxicity and outcomes in irinotecan/ 5-Fluorouracil (5FU)-treated patients is still controversial. The aim of this work was to determine whether UGT1A1, UGT1A7, and UGT1A9 as well as TS polymorphisms affect toxicities and/or outcomes of Spanish patients with advanced colorectal cancer (mCRC) Methods: A total of 149 patients with mCRC were treated either with weekly irinotecan plus high-dose 5FU (FUIRI) or biweekly irinotecan plus 5FU/Leucovorin (FOLFIRI) as first-line chemotherapy (Aranda E; Ann Oncol. 2008 Aug 20). Genomic DNA was extracted from peripheral blood and genotyped using allelic discrimination and direct sequencing. Chi-square test, Fisher's exact test and logistic regression were used to study the association of genotypes with toxicity and response. Log rank and cox regression were used in survival analysis. All statistical tests were two-sided. Results: According to TS 5’TRP genotypes, 79.3% of the 2R/2R patients responded to therapy while only 52.5% of 2R/3R or 3R/3R patients do so (HR=3.5; 95% CI=1.3- 9.1; p=0.009). TS genotypes were not associated with toxicity. UGT1A1*28 TA7/TA7 genotype was clearly associated with severe toxicity (HR=12.7; 95% CI=3.1–51.3; p=0.001) and diarrhea (HR=4; 95% CI=1.3–12; p=0.016) when compared to TA6/TA7 and TA6/TA6 genotypes. These patients also experienced more severe neutropenia (40% vs. 18.8%, p=0.087) and more frequent dose reductions (53.3% vs. 38.1%, p=ns). UGT1A7*3/*3 and UGT1A9–118(dT)9/9 were associated with severe diarrhea (50% vs. 27% p=0.032 and 43% vs. 23% p=0.012). When all non-favourable genotypes (TA7/TA7, *3/*3 and 9/9) were taken into account, there was a statistically significant association with severe diarrhea (HR=4.5; 95% CI 1.3–16.3; p=0.021), neutropenia (HR=3.5; 95% CI=1–12.7; p=0.047) and both (HR=12.4; 95% CI=2.8–54.2; p=0.001). Conclusions: Our data clearly link UGT1A genotypes with irinotecan-related severe toxicity. TS 5’TRP genotypes are predictive of response to irinotecan/5FU first-line chemotherapy.

No significant financial relationships to disclose.

In vitro-acquired resistance gene expression profile and in vivo response to oxaliplatin-based treatment

e15041

Background: Resistance to oxaliplatin is one of the main problems of colorectal cancer (CRC) treatment success. It is not clear if intrinsic and acquired resistance processes are developed by related mechanisms. In a previous work (Martinez-Cardús et al. Mol Cancer Ther, January 2009), we determined a profile of oxaliplatin-acquired resistance related genes by using an in vitro model. In the present work, we analyzed this genetic profile in paraffin-embedded primary adenocarcinomas from CRC patients treated with oxaliplatin-fluoropyrimidine. mRNA expression data was correlated with response rate and time to progression (TTP) in order to determine the role of these genes as markers of resistance to oxaliplatin-based treatment. Material and Method: mRNA levels were analyzed by using Real Time PCR. β-actin and 18s were used as housekeeping genes and, as a reference sample, we used commercial pool of mRNA from different human tumours. Chi- square and Fisher test were used in order to value differences in response rate to treatment. TTP was studied by using Kaplan Meyer curves and Log rank test. Median and percentile 33 and 66 were used as threshold values to determine both high and low expression level groups for each gene analyzed. We considered statistically significant a two-sided p-value lower than 0.05. Results: Forty-four advanced CRC patients treated with fluoropyrimidine plus oxaliplatin were analyzed. 54.5% of them were males; primary tumour was localized in colon in a 65.9% of cases. According to qRT-PCR analysis, the in vitro oxaliplatin acquired resistance related genes could be detected in the tumours but the expression of any of them correlated significantly with in vivo resistance to oxaliplatin-based treatment by using the three different threshold values to define groups. Conclusions: According to our results, these genes could not be used as markers of resistance to oxaliplatin-based treatment in non-treated tumours. Thereby, oxaliplatin resistance acquisition genes seems not to be involved in intrinsic drug resistance probably due to the fact that acquired and intrinsic oxaliplatin resistance are not related mechanisms. Further studies to typify oxaliplatin intrinsic resistance potential markers are guaranteed.

No significant financial relationships to disclose.

[Pneumomediastinum and extensive subcutaneous emphysema after normal labor]

Spontaneous pneumomediastinum associated with subcutaneous emphysema is a rare, though life-threatening, complication of late pregnancy and labor. We report the case of a primipara who, after undergoing normal labor and delivery of a normal-weight baby, developed pneumomediastinum and extensive subcutaneous emphysema with significant symptoms within minutes of delivery. This peripartum complication is usually self-limiting when the aggravating factors are no louguer present. Management includes strict monitoring of the patient and conservative treatment of symptoms.