Gastrointestinal symptom burden in diabetic autonomic and peripheral neuropathy - A Danes cohort study

OBJECTIVE

We investigated associations between gastrointestinal symptoms - evaluated as a combined weighted symptom score (CWSS) - Diabetic autonomic neuropathy (DAN), and distal symmetrical polyneuropathy (DSPN) in type 1 and type 2 diabetes.

RESEARCH DESIGN AND METHODS

Cross-sectional study in a tertiary outpatient clinic. CWSS was calculated based on questionnaires: gastroparesis composite symptom index (GCSI) and gastrointestinal symptom rating score (GSRS). DAN and DSPN were addressed using the composite autonomic symptom score 31 (COMPASS-31) questionnaire, cardiac autonomic reflex tests (CARTs), electrochemical skin conductance (ESC), vibration perception threshold (VPT), Michigan Neuropathy Screening Instrument (MNSI), pain- and thermal sensation. Analyses were adjusted for age, sex, diabetes duration, smoking, LDL-cholesterol, HbA1C and systolic blood pressure. Type 1 and type 2 diabetes were evaluated separately.

RESULTS

We included 566 with type 1 diabetes and 377 with type 2 diabetes. Mean ± SD age was 58 ± 15 years and 565 (59.9 %) were women. A high CWSS was present in 143 (25 %) with type 1 and 142 (38 %) with type 2 diabetes. The odds of DAN by COMPASS-31 (p < 0.001) were higher in the high score group. For type 1 diabetes, odds of cardiac autonomic neuropathy were higher in the high CWSS group. The odds of DSPN by VPT and MNSI in type 1 diabetes, and by ESC, VPT and pain sensation in type 2 diabetes were higher in the high CWSS group.

CONCLUSIONS

A high symptom score was associated with neuropathy by COMPASS-31 and vibration perception. Gastrointestinal symptom burden associated inconsistently with other neuropathy tests between diabetes types.

Revisiting the Landscape of Potential Small and Drug Substance Related Nitrosamines in Pharmaceuticals

N-Nitrosamines are a class of indirect acting mutagens, as their metabolic degradation leads to the formation of the DNA-alkylating diazonium ion. Following up on the in-silico identification of thousands of nitrosamines that can potentially be derived from small molecule drugs and their known impurities described in a previous publication, we have now re-analyzed this dataset to apply EMA's Carcinogenic Potency Categorization Approach (CPCA) introduced with the 16th revision of their Q&A document for Marketing Authorization Holders. We find that the majority of potential nitrosamines from secondary amine precursors belongs to potency categories 4 and 5, corresponding to an acceptable daily intake of 1500 ng, whereas nitrosamines from tertiary amine precursors distribute more evenly among all categories, resulting in a substantial number of structures that are assigned the more challenging acceptable intakes of 18 ng/day and 100 ng/day for potency categories 1 and 2, respectively. However, the nitrosative dealkylation pathway for tertiary amine is generally far slower than the direct nitrosation on secondary amines, with a direct nitrosation mechanism suspected only for structures featuring electron-rich (hetero)aromatic substituents. This allows for greater focus towards those structures that require further review, and we demonstrate that their number is not substantial. In addition, we reflect on the nitrosamine risk posed by secondary amine API impurities and demonstrate that based on the ICH Q3A/B identification threshold unknown impurities may exist that could be transformed to relevant amounts of NA. We also demonstrate that the analytical sensitivity required for the quantification of high potency nitrosamines can be problematic especially for high dose APIs. In summary, the regulatory framework rolled out with the latest Q&A document represents a substantial improvement compared with the previous situation, but further refinement through interaction between manufacturers, regulators, not-for-profit and academic institutions will be required to ensure patient access to vital medicines without compromising safety.

Probiotic containing Lactobacillus reuteri DSM 17648 as an adjunct treatment for Helicobacter pylori infection: A randomized, double-blind, placebo-controlled trial

BACKGROUND

Despite multiple therapy regimens, the decline in the Helicobacter pylori eradication rate poses a significant challenge to the medical community. Adding Lactobacillus reuteri probiotic as an adjunct treatment has shown some promising results. This study aims to investigate the efficacy of Lactobacillus reuteri DSM 17648 in H. pylori eradication and its effect in ameliorating gastrointestinal symptoms and adverse treatment effects.

MATERIALS AND METHODS

This randomized, double-blinded, placebo-controlled trial involved treatment-naïve H. pylori-positive patients. Ninety patients received standard triple therapy for 2 weeks before receiving either a probiotic or placebo for 4 weeks. The posttreatment eradication rate was assessed via a 14 C urea breath test in Week 8. The Gastrointestinal Symptom Rating Scale (GSRS) questionnaire and an interview on treatment adverse effects were conducted during this study.

RESULTS

The eradication rate was higher in the probiotic group than in the placebo group, with a 22.2% difference in the intention-to-treat analysis (91.1% vs. 68.9%; p = 0.007) and 24.3% difference in the per-protocol analysis (93.2% vs. 68.9%; p = 0.007). The probiotic group showed significant pre- to post-treatment reductions in indigestion, constipation, abdominal pain, and total GSRS scores. The probiotic group showed significantly greater reductions in GSRS scores than the placebo group: indigestion (4.34 ± 5.00 vs. 1.78 ± 5.64; p = 0.026), abdominal pain (2.64 ± 2.88 vs. 0.89 ± 3.11; p = 0.007), constipation (2.34 ± 3.91 vs. 0.64 ± 2.92; p = 0.023), and total score (12.41 ± 12.19 vs. 4.24 ± 13.72; p = 0.004). The probiotic group reported significantly fewer adverse headache (0% vs. 15.6%; p = 0.012) and abdominal pain (0% vs. 13.3%; p = 0.026) effects.

CONCLUSIONS

There was a significant increase in H. pylori eradication rate and attenuation of symptoms and adverse treatment effects when L. reuteri was given as an adjunct treatment.

[Characteristic of eating behavior in functional dispepsy]

Functional dyspepsia is the actual problem of modern gastroenterology, its manifestations contribute to the lifting of lifestyle and nutrition. However, a comprehensive assessment of the effect of violations of food behavior, the distribution of adipose tissue and the level of gosters regulating appetite on the severity of gastroenterological symptoms in individuals with various types of functional dyspepsia hasn't been carried out yet. Aim - to clarify the effect of food behavior, ghrelin and leptin blood concentrations on clinical symptoms in patients with different types of functional dyspepsia. Material and methods. A prospective study with the participation of 90 people aged 22.3±0.2, divided into 3 groups was carried out: patients with postprandial distress syndrome (PDS), patients with epigastric pain syndrome (EPS), and practically healthy. All respondents were interviewed using the GSRS, DEBQ questionnaires, their anthropometric data have been defined, body composition indicators were calculated based on the measurement of body circumference measurements, leptin and ghrelin concentration in blood serum was measured by the enzyme immunoassay method. Results and discussion. EPS was characterized by more pronounced symptoms (10.10±0.32 points on the GSRS questionnaire) due to abdominal pain syndrome (4.33±0.51 points) compared with patients with PDS and healthy individuals. In both variants of the functional dyspepsia, all three types of food behavior disorders were revealed, however, the external type was more characteristic for PDS. Patients with PDS had a larger volume of visceral adipose tissue (42.84% of the total fat tissue in the body) than those with EPS (34.02%) and healthy ones (35.55%). Blood leptin concentration in patients with both variants of the functional dyspepsia was lower (especially in patients with EPS - 0.17±0.03 ng/ml, p=0.039) than in healthy (0.32±0.08 ng/ml). Ghrelin level in patients with EPS (14.91±0.17 ng/ml) was significantly higher than in healthy (11.55±0.44 ng/ml, p=0.022). Factor analysis made it possible to identify the stress factor showing the connection of emotional disorders of food behavior with increasing gastrointestinal symptoms and blood leptin concentration and decreasing blood ghrelin level. Conclusion. Different variants of functional dyspepsia are characterized by their own peculiarities of eating behavior, the distribution of fat in the body, the degree of changes in leptin and ghrelin levels, which determine their clinical symptoms. The identification and accounting of these factors will make it possible to individualize the approach to the curation of patients with functional dyspepsia.

Regulatory landscape of nanotechnology and nanoplastics from a global perspective

Nanotechnology and more particularly nanotechnology-based products and materials have provided a huge potential for novel solutions to many of the current challenges society is facing. However, nanotechnology is also an area of product innovation that is sometimes developing faster than regulatory frameworks. This is due to the high complexity of some nanomaterials, the lack of a globally harmonised regulatory definition and the different scopes of regulation at a global level. Research organisations and regulatory bodies have spent many efforts in the last two decades to cope with these challenges. Although there has been a significant advancement related to analytical approaches for labelling purposes as well as to the development of suitable test guidelines for nanomaterials and their safety assessment, there is a still a need for greater global collaboration and consensus in the regulatory field. Furthermore, with growing societal concerns on plastic litter and tiny debris produced by degradation of littered plastic objects, the impact of micro- and nanoplastics on humans and the environment is an emerging issue. Despite increasing research and initial regulatory discussions on micro- and nanoplastics, there are still knowledge gaps and thus an urgent need for action. As nanoplastics can be classified as a specific type of incidental nanomaterials, current and future scientific investigations should take into account the existing profound knowledge on nanotechnology/nanomaterials when discussing issues around nanoplastics. This review was conceived at the 2019 Global Summit on Regulatory Sciences that took place in Stresa, Italy, on 24-26 September 2019 (GSRS 2019) and which was co-organised by the Global Coalition for Regulatory Science Research (GCRSR) and the European Commission's (EC) Joint Research Centre (JRC). The GCRSR consists of regulatory bodies from various countries around the globe including EU bodies. The 2019 Global Summit provided an excellent platform to exchange the latest information on activities carried out by regulatory bodies with a focus on the application of nanotechnology in the agriculture/food sector, on nanoplastics and on nanomedicines, including taking stock and promoting further collaboration. Recently, the topic of micro- and nanoplastics has become a new focus of the GCRSR. Besides discussing the challenges and needs, some future directions on how new tools and methodologies can improve the regulatory science were elaborated by summarising a significant portion of discussions during the summit. It has been revealed that there are still some uncertainties and knowledge gaps with regard to physicochemical properties, environmental behaviour and toxicological effects, especially as testing described in the dossiers is often done early in the product development process, and the material in the final product may behave differently. The harmonisation of methodologies for quantification and risk assessment of nanomaterials and micro/nanoplastics, the documentation of regulatory science studies and the need for sharing databases were highlighted as important aspects to look at.

Gastrointestinal quality of life before and short- and long-term after Roux-en-Y gastric bypass for severe obesity

BACKGROUND

Overall quality of life (QoL) is generally improved after bariatric surgery. Gastrointestinal (GI) symptoms including abdominal pain have been reported in up to >30% of patients after Roux-en-Y gastric bypass (RYGB), and may negatively influence QoL, especially GI-QoL.

OBJECTIVES

To evaluate the evolution of GI symptoms and GI-QoL short- and long-term after RYGB.

SETTING

Two public hospitals METHODS: Candidates for bariatric surgery (n = 128, BMI = 44.2 ± 7.4) or patients who had undergone RYGB 2-4 years (n = 161, BMI = 29.3 ± 15.9) and 5-10 years (n = 121, BMI = 31.3 ± 6.5) before were invited to complete a questionnaire combining 3 validated questionnaires (GIQLI, GSRS, and PCS) specifically designed to evaluate GI-QoL. Scores were compared between the preoperative, early, and late postoperative periods.

RESULTS

The GIQLI score improved from 88.1 before surgery to 118.6 (P < .0001) and 109.7 (P < .0001) in the early and late postoperative periods respectively. GSRS score improved from 15.6 to 10.1 (P = .0001) and 12.8 (P = .012), and PCS-score improved from 19 to 4.5 (P = .0001) and 8.3 (P = .0001), respectively. The GI subscore of the GIQLI improved from 57.4 to 62.1 (P = .007) in the early period but was not significantly different in the late period (59.3 versus 57.4, P = .3). The psychological impact of GI symptoms decreased at both postoperative time points.

CONCLUSION

GI-QoL is markedly improved after RYGB, and this improvement persists up to 10 years. GI symptoms decrease early after surgery and do not worsen in the longer term. Their psychological impact is markedly reduced.

Gastrointestinal Physiology Before and After Duodenal Switch with Comparisons to Unoperated Lean Controls: Novel Use of the SmartPill Wireless Motility Capsule

Purpose

Bariatric surgery alters gastrointestinal anatomy. In this exploratory study, the SmartPill® wireless motility capsule (WMC) was used to study changes in gastrointestinal physiology following biliopancreatic diversion with duodenal switch (BPD/DS).

Material and Methods

Twenty-eight BPD/DS patients (35 ± 11 years, 50% females, body mass index [BMI] 56 ± 5) were to be examined preoperatively and postoperatively. In addition to transit time, appetite control and gastrointestinal symptoms were studied by patient-scored questionnaires (visual analogue scale and Gastrointestinal Symptom Rating Scale (GSRS)). Data was compared to 41 lean unoperated controls.

Results

About 1.8 years postoperatively, 18 patients (BMI 35.8 ± 8.3) returned for a second WMC test. As expected, small bowel transit time was reduced, from 3.9 ± 1.6 h to 2.8 ± 2.0, p = 0.02, and at both these time points, it was shorter than in lean controls (5.4 ± 1.9 h, p = 0.001). Postoperatively, a trend towards reduced colon and whole gut transit times was seen in BPD/DS-patients, thus approaching those of lean controls. Surprisingly, BPD/DS patients scored higher satiety than controls preoperatively as well as increased hunger and desire to eat postoperatively. Compared to lean, BPD/DS patients reported a higher total GSRS score at both time points (1.2 ± 0.2 vs 1.7 ± 0.6 and 2.3 ± 0.5, p < 0.001). Postoperatively, the scores for diarrhea and indigestion increased.

Conclusions

The novel use of the SmartPill system in BPD/DS patients gave the expected readouts. Although small bowel transit time was further shortened after BPD/DS, whole gut transit time did not differ from controls. Typical gastrointestinal symptoms were reported postoperatively.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s11695-021-05452-4.

Regulatory landscape of dietary supplements and herbal medicines from a global perspective

The number of Individuals that use dietary supplements and herbal medicine products are continuous to increase in many countries. The context of usage of a dietary supplement varies widely from country-to-country; in some countries supplement use is just limited to general health and well-being while others permit use for medicinal purposes. To date, there is little consensus from country to country on the scope, requirements, definition, or even the terminology in which dietary supplement and herbal medicines categories could be classified. Transparent science-based quality standards for the ingredients across these regulatory frameworks/definitions becomes even more important given the international supply chain. Meanwhile, there has been a rapid advancement in emerging technologies and data science applied to the field. This review was conceived at the Global Summit on Regulatory Sciences that took place in Beijing on September 2018 (GSRS2018) which is organized by Global Coalition for Regulatory Science Research (GCRSR) that consists of the global regulatory agencies from over ten countries including the European Union. This review summarizes a significant portion of discussions relating to a longitudinal comparison of the status for dietary supplements and herbal medicines among the different national jurisdictions and to the extent of how new tools and methodologies can improve the regulatory application.

Gastrointestinal Tolerance and Microbiome Response to Snacks Fortified with Pea Hull Fiber: A Randomized Trial in Older Adults

BACKGROUND

Consuming foods with added fiber may help older adults achieve fiber recommendations; however, many high-fiber ingredients have little effect on laxation and may contribute to unpleasant gastrointestinal side effects.

OBJECTIVES

The aim of the study was to determine the effects of consuming snacks fortified with pea hull fiber (PHF) on stool frequency and form, gastrointestinal symptoms, and appetite in older adults. An exploratory aim was to determine if PHF altered the microbiota profile.

METHODS

A 10-wk, randomized, blinded, crossover study was carried out. Following a 2-wk baseline period, participants [aged (mean ± SD) 69.7 ± 6.5 y; n = 31; 14 men, 17 women] consumed snacks providing 10 g/d of PHF or a control, each for 2-wk periods followed by 2-wk washouts. Participants used the Bristol Stool Form Scale (BSFS) to record daily stool frequency and gastrointestinal symptoms, and completed the Gastrointestinal Symptom Rating Scale (GSRS) and Simplified Nutritional Appetite Questionnaire (SNAQ) biweekly. One stool was collected per period for 16S ribosomal RNA high-throughput amplicon sequencing of the fecal microbiota profile.

RESULTS

Participants reported 1.63 ± 0.05 stools/d and 76.6% normal transit stool form at baseline and no change with PHF. GSRS syndrome scores were similarly unchanged. Daily abdominal noises and bloating were higher for PHF versus control, and flatulence was higher for PHF versus baseline, suggesting fermentation in some individuals. There was no evidence to suggest a common PHF-induced microbiome response for the group as a whole; however, a subgroup of participants (n = 7) who responded with increased flatulence (fermenters), harbored many different taxa than nonfermenters, and demonstrated lower abundance of Clostridiales with PHF. Appetite was unchanged with PHF.

CONCLUSIONS

PHF did not modulate stool form or frequency in older adults with normal bowel habits. Because snacks fortified with PHF did not suppress appetite, PHF may be an appropriate fiber source for older adults at nutritional risk. Microbiome profile may be predictive of gastrointestinal symptom response to PHF. This trial was registered at www.clinicaltrials.gov as NCT02778230.

Migalastat improves diarrhea in patients with Fabry disease: clinical-biomarker correlations from the phase 3 FACETS trial

Background

Fabry disease is frequently characterized by gastrointestinal symptoms, including diarrhea. Migalastat is an orally-administered small molecule approved to treat the symptoms of Fabry disease in patients with amenable mutations.

Methods

We evaluated minimal clinically important differences (MCID) in diarrhea based on the corresponding domain of the patient-reported Gastrointestinal Symptom Rating Scale (GSRS) in patients with Fabry disease and amenable mutations (N = 50) treated with migalastat 150 mg every other day or placebo during the phase 3 FACETS trial (NCT00925301).

Results

After 6 months, significantly more patients receiving migalastat versus placebo experienced improvement in diarrhea based on a MCID of 0.33 (43% vs 11%; p = .02), including the subset with baseline diarrhea (71% vs 20%; p = .02). A decline in kidney peritubular capillary globotriaosylceramide inclusions correlated with diarrhea improvement; patients with a reduction > 0.1 were 5.6 times more likely to have an improvement in diarrhea than those without (p = .031).

Conclusions

Migalastat was associated with a clinically meaningful improvement in diarrhea in patients with Fabry disease and amenable mutations. Reductions in kidney globotriaosylceramide may be a useful surrogate endpoint to predict clinical benefit with migalastat in patients with Fabry disease.

Trial registration

NCT00925301; June 19, 2009.

Assessment of colonic contents in patients with chronic constipation using MRI

Although chronic constipation is common, colonic functional evaluating tests are uncommon. This study examines whether chronic constipation and gastrointestinal symptoms are correlated with the lateral diameter of the colon measured from MRI images. We included chronic constipation patients in a prospective, cross-sectional study using MRI at three centers. We divided 3D MRI colorectal images into 6 segments using with specified sequences and selected the maximum luminal diameter from each segment. We used the GSRS questionnaire to evaluate gastrointestinal symptoms. We evaluated the correlation between luminal diameters and GSRS scores. We found the following positive correlations: descending colon and unsatisfactory defecation symptoms; sigmoid colon and diarrhea; and rectum and constipation. The sum and ratio of the ascending and sigmoid colon diameters correlated with nausea and diarrhea. The sum of the transvers to the sigmoid colon diameter also correlated with nausea and diarrhea. The sum of all segment diameters correlated with nausea and constipation. In conclusion, we showed cross-sectional study of colonic MRI correlate with gastrointestinal symptoms. MRI might be useful for colonic motility evaluations to determine appropriate constipation treatments (Clinical trial registry number UMIN 000021274).

Open Label Trial of the Efficacy and Safety Profile of Rikkunshito used for the Treatment of Gastrointestinal Symptoms in Patients with Parkinson's Disease: A Pilot Study

BACKGROUND

Patients with Parkinson's disease (PD) usually experience distress related not only to motor dysfunction, but also to nonmotor symptoms, including gastrointestinal dysfunction.

OBJECTIVE

The purpose of this pilot study was to evaluate the efficacy and safety profile of a traditional Japanese medicine, rikkunshito (RKT), used for the treatment of gastrointestinal symptoms, associated with anorexia and dyspepsia, in patients with PD.

METHODS

Patients were randomly assigned to either Group A (4-week treatment period with 7.5 g/d RKT followed by a 4-week off-treatment period) or Group B (4-week off-treatment period followed by a 4-week treatment period with 7.5 g/d RKT). Appetite, quality of life for gastrointestinal symptoms, and depression were assessed using a visual analog scale, the Gastrointestinal Symptom Rating Scale and the Self-Rating Depression Scale, respectively. The gastric emptying examination and assay of plasma acylated ghrelin level were performed using the ¹³C-acetate breath test and commercially available assay kits, respectively.

RESULTS

RKT treatment produced a significant increase in the appetite score (1.84 [2.34]; P < 0.05), compared to a decrease in the score over the off-treatment period (-1.36 [2.94]). The mean score for abdominal pain, on the Gastrointestinal Symptom Rating Scale, and for self-reported depression, on the Self-Rating Depression Scale, also decreased significantly with RKT treatment (P < 0.05), compared with the off-treatment period scores. No effect of RKT on plasma acylated ghrelin level and rate of gastric emptying was identified.

CONCLUSIONS

RKT may improve anorexia in patients with PD. The positive effects of RKT on depression and anorexia may improve the overall quality of life of these patients. The benefits of RKT identified in our pilot study will need to be confirmed in a randomized, double-blind, controlled trial. UMIN Clinical Trial Registry identifier: UMIN000009626.

Regulatory bioinformatics for food and drug safety

"Regulatory Bioinformatics" strives to develop and implement a standardized and transparent bioinformatic framework to support the implementation of existing and emerging technologies in regulatory decision-making. It has great potential to improve public health through the development and use of clinically important medical products and tools to manage the safety of the food supply. However, the application of regulatory bioinformatics also poses new challenges and requires new knowledge and skill sets. In the latest Global Coalition on Regulatory Science Research (GCRSR) governed conference, Global Summit on Regulatory Science (GSRS2015), regulatory bioinformatics principles were presented with respect to global trends, initiatives and case studies. The discussion revealed that datasets, analytical tools, skills and expertise are rapidly developing, in many cases via large international collaborative consortia. It also revealed that significant research is still required to realize the potential applications of regulatory bioinformatics. While there is significant excitement in the possibilities offered by precision medicine to enhance treatments of serious and/or complex diseases, there is a clear need for further development of mechanisms to securely store, curate and share data, integrate databases, and standardized quality control and data analysis procedures. A greater understanding of the biological significance of the data is also required to fully exploit vast datasets that are becoming available. The application of bioinformatics in the microbiological risk analysis paradigm is delivering clear benefits both for the investigation of food borne pathogens and for decision making on clinically important treatments. It is recognized that regulatory bioinformatics will have many beneficial applications by ensuring high quality data, validated tools and standardized processes, which will help inform the regulatory science community of the requirements necessary to ensure the safe introduction and effective use of these applications.

Benefits of a gluten-free diet for asymptomatic patients with serologic markers of celiac disease

BACKGROUND & AIMS

We investigated whether screen-detected and apparently asymptomatic adults with endomysial antibodies (EmA) benefit from a gluten-free diet (GFD).

METHODS

We performed a prospective trial of 3031 individuals at risk for celiac disease based on screens for EmA. Of 148 seropositive individuals, 40 fulfilled inclusion criteria and were assigned randomly to groups placed on a GFD or gluten-containing diets. We evaluated ratios of small-bowel mucosal villous height:crypt depth, serology and laboratory test results, gastrointestinal symptom scores, physiologic well-being, perception of health by a visual analog scale, bone mineral density, and body composition at baseline and after 1 year. Thereafter, the group on the gluten-containing diet started a GFD and was evaluated a third time; subjects in the GFD group remained on this diet.

RESULTS

After 1 year on the GFD, the mean mucosal villous height:crypt depth values increased (P < .001), levels of celiac-associated antibodies decreased (P < .003), and gastrointestinal symptoms improved to a greater extent than in patients on gluten-containing diets (P = .003). The GFD group also had reduced indigestion (P = .006), reflux (P = .05), and anxiety (P = .025), and better health, based on the visual analog scale (P = .017), than the gluten-containing diet group. Only social function scores improved more in the gluten-containing diet group than in the GFD group (P = .031). There were no differences between groups in laboratory test results, bone mineral density, or body composition. Most measured parameters improved when patients in the gluten-containing diet group were placed on GFDs. No subjects considered their experience to be negative and most expected to remain on GFDs.

CONCLUSIONS

GFDs benefit asymptomatic EmA-positive patients. The results support active screening of patients at risk for celiac disease. Clinicaltrials.gov no: NCT01116505.

Genetic polymorphisms of UGT1A8, UGT1A9 and HNF-1α and gastrointestinal symptoms in renal transplant recipients taking mycophenolic acid

Mycophenolic acid (MPA), a widely used immunosuppressant, has a complex metabolism that involves a number of enzymes. Some of its metabolites are thought to be the cause of gastrointestinal (GI) side effects. In this study, we investigated whether polymorphisms of UDP-glucuronosyltransferases (UGT1) A8, 1A9, and hepatocyte nuclear factor (HNF1α) genes or pharmacokinetic parameters of mycophenolic acid (MPA) were associated with the severity of GI symptoms in patients receiving MPA therapy. A total of 109 kidney transplant patients taking mycophenolic acid (MPA) derivatives were genotyped for UGT1A8, 1A9 and HNF1α genes. Among these, a total of 15 patients were participants in the pharmacokinetic study. Severity of GI symptoms was assessed using a validated Gastrointestinal Symptom Rating Scale (GSRS). The overall and subscale GSRS scores were measured at 1 week (baseline), 2 weeks, 3 months and 6 months post-transplantation. In the case of the pharmacokinetic study, EC-MPS was administered and a total of nine blood samples were obtained at -1, 0, 0.5, 1, 2, 4, 6, 8, and 12h. Genotypes of UGT1A8 were significantly associated with the overall GSRS scores at week 1 (p=0.02) and week 2 (p=0.036). Subscales were only statistically significant for constipation at week 1 (p=0.002) and indigestion at week 2 (p=0.02), while UGT1A9 was only significant for the constipation at week 1 (p=0.04). HNF1α genotypes were significantly different at week 1 in the overall GSRS (p=0.004), and for abdominal pain (p=0.04), acid reflux (p=0.036) and constipation subscales (p=0.04). In addition, abdominal pain was statistically significantly different at 3 months and 6 months after transplantation (p=0.03 and 0.02, respectively). In the case of the pharmacokinetic study, we have found some correlations between MPAC0 and constipation (p=0.02) where MPAAUC was correlated with acid reflux (p=0.02) and constipation (p=0.012), MPAGCL/F was correlated to acid reflux, indigestion, constipation and the sum of the GSRS scores (p=0.037, p=0.032, p=0.033 and p=0.04, respectively). Multinomial regression analysis for MPAGCL/F showed a statistical significance for the subscale indigestion and the sum of the GSRS (p=0.033 and p=0.037, respectively). Our data suggests that among patients receiving MPA the UGT1A9 alleles might play a role in determining the severity of early GI side effects, while the HNF1α allele appears to be associated with a later effect as well as early side effects. Our data also showed that some kinetic parameters might predict MPA side effects.