High-dose oral thiamine versus placebo for chronic fatigue in patients with primary biliary cholangitis: A crossover randomized clinical trial.

BACKGROUND & AIMS: Fatigue has high negative impact on many patients with primary biliary cholangitis (PBC) and treatment options are limited. Recently we showed favorable effects of four weeks of high-dose thiamine treatment on fatigue in patients with inflammatory bowel disease. We aimed to investigate the effect and safety of high-dose (600-1800 mg daily) oral thiamine treatment on chronic fatigue in patients with PBC. METHODS: Randomized, double-blinded, placebo-controlled crossover trial including patients with severe PBC-related fatigue. Participants were allocated 1:1 to either group 1) 4 weeks of high-dose thiamine, 4 weeks of washout, and 4 weeks of placebo; or group 2) 4 weeks of placebo, washout, and high-dose thiamine, respectively. Fatigue severity was quantified using the fatigue subscale of the PBC-40 questionnaire. The primary outcome was a fatigue reduction of ≥ 5 points after 4 weeks of high-dose thiamine treatment. RESULTS: We enrolled 36 patients; 34 completed the study. The overall mean reduction in fatigue was 5.0 points (95% CI: 2.5 to 7.5; p < 0.001) for the combined group 1 and group 2. Crossover analysis showed a mean increase in fatigue of 0.3 points (95% CI: -4.2 to 3.8) after high-dose thiamine treatment compared to a 1.4 points (95% CI: 6.2 to -3.4) mean reduction after placebo (p = 0.55). Only mild and transient adverse events were recorded. CONCLUSION: Four weeks of high-dose oral thiamine treatment in patients with PBC was well tolerated and safe. However, high-dose thiamine was not superior to placebo in reducing PBC-related fatigue. TRIAL REGISTRATION: The trial was registered in the ClinicalTrials.gov (NCT04893993) and EudraCT (2020-004935-26).

Clinical and biochemical impact of vitamin B6 deficiency in primary sclerosing cholangitis before and after liver transplantation.

BACKGROUND AND AIMS: We previously demonstrated that people with primary sclerosing cholangitis (PSC) had reduced gut microbial capacity to produce active vitamin B6 (pyridoxal 5'-phosphate [PLP]), which corresponded to lower circulating PLP levels and poor outcomes. Here, we define the extent and biochemical and clinical impact of vitamin B6 deficiency in people with PSC from several centers before and after liver transplantation (LT). METHODS: We used targeted liquid chromatography-tandem mass spectrometry to measure B6 vitamers and B6-related metabolic changes in blood from geographically distinct cross-sectional cohorts totaling 373 people with PSC and 100 healthy controls to expand on our earlier findings. Furthermore, we included a longitudinal PSC cohort (n = 158) sampled prior to and serially after LT, and cohorts of people with inflammatory bowel disease (IBD) without PSC (n = 51) or with primary biliary cholangitis (PBC) (n = 100), as disease controls. We used Cox regression to measure the added value of PLP to predict outcomes before and after LT. RESULTS: In different cohorts, 17-38% of people with PSC had PLP levels below the biochemical definition of a vitamin B6 deficiency. The deficiency was more pronounced in PSC than in IBD without PSC and PBC. Reduced PLP was associated with dysregulation of PLP-dependent pathways. The low B6 status largely persisted after LT. Low PLP independently predicted reduced LT-free survival in both non-transplanted people with PSC and in transplant recipients with recurrent disease. CONCLUSIONS: Low vitamin B6 status with associated metabolic dysregulation is a persistent feature of PSC. PLP was a strong prognostic biomarker for LT-free survival both in PSC and recurrent disease. Our findings suggest that vitamin B6 deficiency modifies the disease and provides a rationale for assessing B6 status and testing supplementation. IMPACT AND IMPLICATIONS: We previously found that people with PSC had reduced gut microbial potential to produce essential nutrients. Across several cohorts, we find that the majority of people with PSC are either vitamin B6 deficient or have a marginal deficiency, which remains prevalent even after liver transplantation. Low vitamin B6 levels strongly associate with reduced liver transplantation-free survival as well as deficits in biochemical pathways dependent on vitamin B6, suggesting that the deficiency has a clinical impact on the disease. The results provide a rationale for measuring vitamin B6 and to investigate whether vitamin B6 supplementation or modification of the gut microbial community can help improve outcomes for people with PSC.

Association between fibrosis markers and kidney function following peptide receptor radionuclide therapy in patients with neuroendocrine tumours.

Peptide receptor radionuclide therapy (PRRT) is a treatment for neuroendocrine tumours (NET). Renal impairment is a known side effect due to kidney fibrosis. We investigated the association between novel specific fibrosis markers and kidney function following PRRT. We included 38 patients who had all finished PRRT. In serum and urine, we analysed levels of three different fibrosis markers, PRO-C6 (type VI collagen formation), PRO-C3 (type III collagen formation) and C3M (type III collagen degradation). We determined kidney function by the 51Cr-EDTA plasma clearance. We used Wilcoxon rank sum test and Spearman's rank correlation to evaluate the association between the fibrosis markers and kidney function. We included 38 NET patients, 25 small-intestinal NET, 6 pancreatic NET, 2 pulmonary NET and 5 other types of NET. Median age was 69 years (IQR: 61-73). Median time from last PRRT to inclusion was 8 months (IQR: 3-20). We found significantly increased levels of serum PRO-C6 (p = .007) and urinary PRO-C6 (p = .033) and significantly decreased levels of urinary C3M (p = .035) in patients with impaired kidney function. Further, we observed a negative association between serum PRO-C6 and kidney function (rho = -0.33, p = .04) and a positive association between urinary C3M and kidney function (rho = 0.37, p = .02). We showed an association between the three fibrosis markers, serum PRO-C6, urinary PRO-C6 and urinary C3M and kidney function. These markers may help to improve the understanding of potential pathological tissue turnover and potentially improve monitoring of kidney function after PRRT in NET patients.