This is a prospective, multicenter study of a cohort of 224 cystic fibrosis (CF) patients treated with CF transmembrane conductance regulator (CFTR) modulators (CFTRm). Our aim was to prospectively analyze the effect of CFTRm treatment on fat‐soluble vitamin serum levels. Demographic and clinical data were recorded, and fat‐soluble vitamin levels were analyzed at baseline, and at 6 and 12 months after starting treatment. Two groups were analyzed separately: patients receiving dual therapy lumacaftor/ivacaftor or tezacaftor/ivacaftor (Lum/Tez+Iva), and those on triple therapy with elexacaftor/tezacaftor/ivacaftor (ETI). We found that treatment with ETI produced a significant increase in vitamin D and A levels within the first 6 months, which was maintained at 12 months. However, with dual therapy, we observed an increase only in vitamin A levels within the first 6 months, which was not maintained at 12 months. No differences were found in vitamin E serum levels between the groups.

Objectives/Background: Vitamin D-binding protein (VDBP) and free vitamin D are new markers that are being studied as a possible markers of vitamin D status. The main aim of our study was to analyze the VDBP genotype and quantify the levels of free vitamin D in a sample of cystic fibrosis (CF) patients. Methods: We conducted a multicenter, cross-sectional, and prospective study including patients with CF and exocrine pancreatic insufficiency who were clinically stable. We investigated vitamin D levels (total and free) and the different VDBP haplotypes. Free vitamin D levels were measured using an electro-chemiluminescence assay. Results: A sample of 48 patients was obtained (52% male; median age 13.8 years). The most common allele of VDBP was Gc1s (72%) > Gc2 (52%) > Gc1f (27%). The median calcidiol was 21.2 ng/mL (IR 15.3–26.9), and 81% had levels in the insufficiency range: 23 patients (48%) below 20 ng/mL, and 16 (33%) between 20 and 30 ng/mL. The median free vitamin D level was 4.2 pg/mL (IR 3.9–5.6). A positive correlation was observed between calcidiol and free vitamin D levels (r = 0.871; p < 0.0001). After adjustment for season, vitamin D supplementation, sex, and CF-related diabetes, patients with Gc1f polymorphism had a lower risk of vitamin D deficiency, OR 0.22 (95% CI 0.05–0.99), and p = 0.027. A negative linear trend was observed between the polymorphisms grouped into three categories (Gc1/Gc1, Gc1/Gc2, and Gc2/Gc2, in that order) and vitamin D and free vitamin D levels (p = 0.025 and p = 0.033, respectively). Conclusion: In CF, as in the general population, the most common VDBP haplotype in the Caucasian race is Gc1s. VDBP polymorphisms influence serum vitamin D and free vitamin D levels in CF patients. There is a good correlation between free vitamin D and calcidiol levels, suggesting that measuring the latter in CF does not seem to provide any additional benefit.

Objetives/Background: Vitamin D Binding Protein (VDBP) and free vitamin D are new markers that are being studied as a possible markers of vitamin D status. The main aim of our study was to analyse the VDBP genotype and quantify the levels of VDBP and free vitamin D in a sample of cystic fibrosis (CF) patients. Methods: Multicentre, cross-sectional and prospective study including patients with CF, exocrine pancreatic insufficiency who were clinically stable. We investigated vitamin D levels (total and free) and the different VDBP haplotypes. Free vitamin D levels were measured using an electro-chemiluminescence assay. Results: A sample of 48 patients was obtained (52% male; median age 13.8 years). The most common allele of VDBP was Gc1s (72%)>Gc2 (52%)>Gc1f (27%). Median calcidiol was 21.2 ng/ml (IR 15.3 - 26.9), 81% had levels in the insufficiency range: 23 patients (48%) below 20 ng/ml, and 16 (33%) between 20 and 30 ng/ml. The median free vitamin D level was 4.2 pg/ml (IR 3.9 – 5.6). A positive correlation was observed between calcidiol and free vitamin D levels (r=0.871; p<0.0001). After adjustment for season, vitamin D supplementation, sex and CFrelated diabetes, patients with Gc1f polymorphism had a lower risk of vitamin D deficiency, OR 0.22 (95% CI 0.05 – 0.99), p=0.027. A negative linear trend was observed between the polymorphisms grouped into 3 categories (Gc1/Gc1, Gc1/Gc2, and Gc2/Gc2, in that order) and vitamin D and free vitamin D levels (p=0.025 and p=0.033, respectively). Conclusion: In CF, as in the general population, the most common VDBP haplotype in Caucasian race is Gc1s. VDBP polymorphisms influence serum vitamin D and free vitamin D levels in CF patients. There is a good correlation between free vitamin D and calcidiol levels, suggesting that measuring the latter in CF does not seem to provide any additional benefit.

Allogeneic hematopoietic stem cell transplantation (HSCT) is a medical procedure to treat hematologic malignancies and restore bone marrow function. However, this approach may lead to graft-versus-host disease (GvHD), a major cause of mortality and morbidity after allogeneic HSCT. Some studies have suggested the involvement of gut microbiota in the development and prognosis of GvHD. In this context, the main objective of this study was to compare the fecal microbiome composition and short-chain profile of pediatric patients who underwent successful HSCT, developed GvHD or died. The bacterial composition was analyzed using 16S rRNA gene sequencing, while short-chain fatty acids (SCFAs) were quantified by gas chromatography. Fecal samples at engraftment were mainly characterized by a loss of bacterial diversity, a depletion of sequences belonging to the genus Blautia and significantly lower concentrations of fecal butyrate and acetate compared with those obtained before HSCT and 100 days after HSCT. Our findings confirm that children experiencing GvHD after HSCT have distinct gut microbiota and SCFA profiles, which might contribute to developing new microbiota-targeted strategies for GvHD prevention during HSCT procedures.