Clinical and genetic factors predicting response to therapy in patients with Crohn’s disease

Aim - To identify clinical and/or genetic predictors of response to several therapies in Crohn’s disease (CD) patients. Methods - We included 242 patients with CD (133 females) aged (mean ± standard deviation) 39 ± 12 years and a disease duration of 12 ± 8 years. The single-nucleotide polymorphisms (SNPs) studied were ABCB1 C3435T and G2677T/A, IL23R G1142A, C2370A, and G9T, CASP9 C93T, Fas G670A and LgC844T, and ATG16L1 A898G. Genotyping was performed with real-time PCR with Taqman probes. Results - Older patients responded better to 5-aminosalicylic acid (5-ASA) and to azathioprine (OR 1.07, p = 0.003 and OR 1.03, p = 0.01, respectively) while younger ones responded better to biologicals (OR 0.95, p = 0.06). Previous surgery negatively influenced response to 5-ASA compounds (OR 0.25, p = 0.05), but favoured response to azathioprine (OR 2.1, p = 0.04). In respect to genetic predictors, we observed that heterozygotes for ATGL16L1 SNP had a significantly higher chance of responding to corticosteroids (OR 2.51, p = 0.04), while homozygotes for Casp9 C93T SNP had a lower chance of responding both to corticosteroids and to azathioprine (OR 0.23, p = 0.03 and OR 0.08, p = 0.02,). TT carriers of ABCB1 C3435T SNP had a higher chance of responding to azathioprine (OR 2.38, p = 0.01), while carriers of ABCB1 G2677T/A SNP, as well as responding better to azathioprine (OR 1.89, p = 0.07), had a lower chance of responding to biologicals (OR 0.31, p = 0.07), which became significant after adjusting for gender (OR 0.75, p = 0.005). Conclusions - In the present study, we were able to identify a number of clinical and genetic predictors of response to several therapies which may become of potential utility in clinical practice. These are preliminary results that need to be replicated in future pharmacogenomic studies.

Modulation of inflammatory mediators by Opuntia ficus-indica and Prunus avium bioproducts using an in vitro cell-based model of intestinal inflammation

Dissertation to obtain a Master Degree in Biotechnology

Pyoderma Gangrenosum Associated with Sclerosing Cholangitis, Type 1 Diabetes Mellitus and Ulcerative Colitis

We describe the case of a 22-year-old black female with type 1 diabetes mellitus diagnosed when she was 12 years old. She first presented (March 1994) with pustules and ulcerations on the upper and lower limbs, trunk and scalp at the age 17. The diagnosis of pyoderma gangrenosum was made. Since presentation, changes in liver function were detected and subsequent study led to the diagnosis of sclerosing cholangitis. The diagnosis of ulcerative colitis was made after colonoscopy. Partial response was obtained with minocycline and clofazimine, but treatment with 5-aminosalicylic acid achieved no improvement of the ulcerations. Liver transplantation, followed by immunosuppressive therapy led to complete regression of the cutaneous lesions.

Best practice in the management of mild-to-moderately active ulcerative colitis and achieving maintenance of remission using mesalazine.

Optimizing treatment goals in ulcerative colitis requires recognizing the needs of patients. It is increasingly recognized that adapting treatment strategies aligned with patient needs can improve patient compliance and consequently minimize relapse rates. Tailoring of treatment strategies can improve not only patient quality of life, and decrease the number harmed by adverse events from more potent drugs, but can also save valuable healthcare costs by avoiding high-cost treatment interventions associated with acute ulcerative colitis. This review will consider several elements of mesalazine management from the patient perspective based on a range of clinical and patient-focused evidence. By highlighting patient preferences in disease management it is envisaged that this review will aid physicians to optimize treatment decisions with the different mesalazine preparations available.

Topische Therapie bei Colitis ulcerosa [Topical therapy of ulcerative colitis].

The availability of new topical preparations for the treatment of left sided ulcerative colitis ulcerosa offers a therapy optimization for many patients. Rectal application of steroids and 5-aminosalicylic acid (5-ASA) is associated with fewer side effects and has a higher therapeutic efficacy in mild to moderate-active left-sided colitis as compared to a systemic therapy. Often it is argued that the patients' compliance is insufficient with a rectal therapy. However, with sufficient information on the proven advantages this is usually not the case. The rectal application of drugs in distal ulcerative colitis is suitable also for the maintenance of remission. Therefore the new therapy guidelines recommend topical therapy more than in former times. Subsequently, these manuscripts focussed specifically on the topical therapy of distal colitis, to elucidate that clear treatment advantages are present in daily practice.

Topical therapy is underused in patients with ulcerative colitis.

The availability of new topical preparations for the treatment of left sided ulcerative colitis offers a therapy optimization for many patients. Rectal application of steroids and 5-aminosalicylic acid (5-ASA) is associated with fewer side effects and has a higher therapeutic efficacy in left-sided colitis as compared to a systemic therapy. Therefore, we were interested in the use of topical therapy in patients with ulcerative colitis. The key question was whether topical treatment is more frequently used than oral therapy in patients with proctitis and left sided colitis. Data of 800 patients of the Swiss IBD cohort study were analyzed. Sixteen percent of patients of the cohort had proctitis, 21% proctosigmoiditis and 41% pancolitis. Topical therapy with 5-ASA or corticosteroids was given in 26% of patients with proctitis, a combined systemic and topical treatment was given in 13%, whereas systemic treatment with 5-ASA without topical treatment was given in 29%. Proportion of topical drug use decreased with respect to disease extension from 39% for proctitis to 13.1% for pancolitis (P=0.001). Patients with severe colitis received a significantly higher dose of topical 5-ASA than patients in remission. Side effects of topical or systemic 5-ASA or budesonide treatment were less frequently seen compared to other medications. Topical treatment was frequently stopped over time. The quality of life was the same in patients with limited disease compared to patients with pancolitis. Topical treatment in proctitis patients was underused in Switzerland. Since topical treatment is safe and effective it should be used to a larger extend.

Topical therapy is underused in patients with ulcerative colitis.

The availability of new topical preparations for the treatment of left sided ulcerative colitis offers a therapy optimization for many patients. Rectal application of steroids and 5-aminosalicylic acid (5-ASA) is associated with fewer side effects and has a higher therapeutic efficacy in left-sided colitis as compared to a systemic therapy. Therefore, we were interested in the use of topical therapy in patients with ulcerative colitis. The key question was whether topical treatment is more frequently used than oral therapy in patients with proctitis and left sided colitis. Data of 800 patients of the Swiss IBD cohort study were analyzed. Sixteen percent of patients of the cohort had proctitis, 21% proctosigmoiditis and 41% pancolitis. Topical therapy with 5-ASA or corticosteroids was given in 26% of patients with proctitis, a combined systemic and topical treatment was given in 13%, whereas systemic treatment with 5-ASA without topical treatment was given in 29%. Proportion of topical drug use decreased with respect to disease extension from 39% for proctitis to 13.1% for pancolitis (P=0.001). Patients with severe colitis received a significantly higher dose of topical 5-ASA than patients in remission. Side effects of topical or systemic 5-ASA or budesonide treatment were less frequently seen compared to other medications. Topical treatment was frequently stopped over time. The quality of life was the same in patients with limited disease compared to patients with pancolitis. Topical treatment in proctitis patients was underused in Switzerland. Since topical treatment is safe and effective it should be used to a larger extend.

Prevalence and risk factors for therapy escalation in ulcerative colitis in the Swiss IBD Cohort Study

BACKGROUND: Physicians traditionally treat ulcerative colitis (UC) using a step-up approach. Given the paucity of data, we aimed to assess the cumulative probability of UC-related need for step-up therapy and to identify escalation-associated risk factors. METHODS: Patients with UC enrolled into the Swiss IBD Cohort Study were analyzed. The following steps from the bottom to the top of the therapeutic pyramid were examined: (1) 5-aminosalicylic acid and/or rectal corticosteroids, (2) systemic corticosteroids, (3) immunomodulators (IM) (azathioprine, 6-mercaptopurine, methotrexate), (4) TNF antagonists, (5) calcineurin inhibitors, and (6) colectomy. RESULTS: Data on 996 patients with UC with a median disease duration of 9 years were examined. The point estimates of cumulative use of different treatments at years 1, 5, 10, and 20 after UC diagnosis were 91%, 96%, 96%, and 97%, respectively, for 5-ASA and/or rectal corticosteroids, 63%, 69%, 72%, and 79%, respectively, for systemic corticosteroids, 43%, 57%, 59%, and 64%, respectively, for IM, 15%, 28%, and 35% (up to year 10 only), respectively, for TNF antagonists, 5%, 9%, 11%, and 12%, respectively, for calcineurin inhibitors, 1%, 5%, 9%, and 18%, respectively, for colectomy. The presence of extraintestinal manifestations and extended disease location (at least left-sided colitis) were identified as risk factors for step-up in therapy with systemic corticosteroids, IM, TNF antagonists, calcineurin inhibitors, and surgery. Cigarette smoking at diagnosis was protective against surgery. CONCLUSIONS: The presence of extraintestinal manifestations, left-sided colitis, and extensive colitis/pancolitis at the time of diagnosis were associated with use of systemic corticosteroids, IM, TNF antagonists, calcineurin inhibitors, and colectomy during the disease course.

Nanotechnological delivery systems for the oral administration of active molecules: Polymeric microparticles and microemulsions applied to anti-inflammatory and anti-infectious drugs

This thesis was devoted to the development of innovative oral delivery systems for two different molecules. In the first part, microparticles (MPs) based on xylan and Eudragit® S- 100 were produced and used to encapsulate 5-aminosalicylic acid for colon delivery. Xylan was extracted from corn cobs and characterized in terms of its physicochemical, rheological and toxicological properties. The polymeric MPs were prepared by interfacial cross-linking polymerization and spray-drying and characterized for their morphology, mean size and distribution, thermal stability, crystallinity, entrapment efficiency and in vitro drug release. MPs with suitable physical characteristics and satisfactory yields were prepared by both methods, although the spray-dried systems showed higher thermal stability. In general, spraydried MPs would be preferable systems due to their thermal stability and absence of toxic agents used in their preparation. However, drug loading and release need to be optimized. In the second part of this thesis, oil-in-water microemulsions (O/W MEs) based on mediumchain triglycerides were formulated as drug carriers and solubility enhancers for amphotericin B (AmB). Phase diagrams were constructed using surfactant blends with hydrophiliclipophilic balance values between 9.7 and 14.4. The drug-free and drug-loaded MEs presented spherical non-aggregated droplets around 80 and 120 nm, respectively, and a low polydispersity index. The incorporation of AmB was high and depended on the volume fraction of the disperse phase. These MEs did not reduce the viability of J774.A1 macrophage-like cells for concentrations up to 25 μg/mL of AmB. Therefore, O/W MEs based on propylene glycol esters of caprylic acid may be considered as suitable delivery systems for AmB

Horseradish peroxidase-catalyzed oxidation of rifampicin: Reaction rate enhancement by co-oxidation with anti-inflammatory drugs

The tuberculostatic drug rifampicin has been described as a scavenger of reactive species. Additionally, the recent demonstration that oral therapy with a complex of rifampicin and horseradish peroxidase (HRP) was more effective than rifampicin alone, in an animal model of experimental leprosy, suggested the importance of redox reactions involving rifampicin and their relevance to the mechanism of action. Hence, we studied the oxidation of rifampicin catalyzed by HRP, since this enzyme may represent the prototype of peroxidation-mediated reactions. We found that the antibiotic is efficiently oxidized and that rifampicin-quinone is the product, in a reaction dependent on both HRP and hydrogen peroxide. The steady-state kinetic constants Km app (101±23 mmol/l), Vmax app (0.78±0.09 μmol/l·s-1) and kcat (5.1±0.6 s-1) were measured (n=4). The reaction rate was increased by the addition of co-substrates such as tetramethylbenzidine, salicylic acid, 5-aminosalicylic acid and paracetamol. This effect was explained by invoking an electron-transfer mechanism by which these drugs acted as mediators of rifampicin oxidation. We suggested that this drug interaction might be important at the inflammatory site. © 2005 Pharmaceutical Society of Japan.

Polymeric Nanoparticles as Oral Delivery Systems for Encapsulation and Release of Polyphenolic Compounds: Impact on Quercetin Antioxidant Activity & Bioaccessibility

A delivery system containing polymeric (Eudragit) nanoparticles has been developed for encapsulation and controlled release of bioactive flavonoids (quercetin). Nanoparticles were fabricated using a solvent displacement method. Particle size, morphology, and charge were measured by light scattering, electron microscopy and zeta-potential. Encapsulation efficiency (EE) and release profiles were determined using electrochemical methods. Molecular interactions within the particle matrix were characterized by X-ray diffraction, differential scanning calorimetry, and infrared spectroscopy. Antioxidant properties of free and encapsulated quercetin were analyzed by TBARS and fluorescence spectroscopy. Bioaccessibility of quercetin was evaluated using an in vitro digestion model. Relatively small (d a parts per thousand aEuro parts per thousand 370 nm) anionic polymeric nanoparticles were formed containing quercetin in a non-crystalline form (EE a parts per thousand aEuro parts per thousand 67 %). The main interaction between quercetin and Eudragit was hydrogen bonding. Encapsulated quercetin remained stable during 6 months storage and maintained its antioxidant activity. Quercetin bioaccessibility within simulated small intestinal conditions was improved by encapsulation. The knowledge obtained from this study will facilitate the rational design and fabrication of polymeric nanoparticles as oral delivery systems for encapsulation, protection, and release of bioactive compounds.

[Topical therapy of ulcerative colitis]

The availability of new topical preparations for the treatment of left sided ulcerative colitis ulcerosa offers a therapy optimization for many patients. Rectal application of steroids and 5-aminosalicylic acid (5-ASA) is associated with fewer side effects and has a higher therapeutic efficacy in mild to moderate-active left-sided colitis as compared to a systemic therapy. Often it is argued that the patients' compliance is insufficient with a rectal therapy. However, with sufficient information on the proven advantages this is usually not the case. The rectal application of drugs in distal ulcerative colitis is suitable also for the maintenance of remission. Therefore the new therapy guidelines recommend topical therapy more than in former times. Subsequently, these manuscripts focussed specifically on the topical therapy of distal colitis, to elucidate that clear treatment advantages are present in daily practice.