Alterations in the fecal microbiota in patients with advanced cystic fibrosis liver disease after 6 months of elexacaftor/tezacaftor/ivacaftor.

BACKGROUND: Cystic fibrosis associated liver disease (CFLD) carries a significant disease burden with no effective preventive therapies. According to the gut-liver axis hypothesis for CFLD pathogenesis, dysbiosis and increased intestinal inflammation and permeability permit pathogenic bacterial translocation into the portal circulation, leading to hepatic inflammation and fibrosis. Evaluating the effect of CFTR (cystic fibrosis transmembrane conductance regulator) modulation with elexacaftor/tezacaftor/ivacaftor (ETI) may help determine the role of CFTR in CFLD and increase understanding of CFLD pathogenesis, which is critical for developing therapies. We aimed to characterize the fecal microbiota in participants with CF with and without advanced CFLD (aCFLD) before and after ETI. METHODS: This is an ancillary analysis of stool samples from participants ages ≥12 y/o enrolled in PROMISE (NCT04038047). Included participants had aCFLD (cirrhosis with or without portal hypertension, or non-cirrhotic portal hypertension) or CF without liver disease (CFnoLD). Fecal microbiota were defined by shotgun metagenomic sequencing at baseline and 1 and 6 months post-ETI. RESULTS: We analyzed 93 samples from 34 participants (11 aCFLD and 23 CFnoLD). Compared to CFnoLD, aCFLD had significantly higher baseline relative abundances of potential pathogens Streptococcus salivarius and Veillonella parvula. Four of 11 aCFLD participants had an initially abnormal fecal calprotectin that normalized 6 months post-ETI, correlating with a significant decrease in S. salivarius and a trend towards decreasing V. parvula. CONCLUSIONS: These results support an association between dysbiosis and intestinal inflammation in CFLD with improvements in both post-ETI, lending further support to the gut-liver axis in aCFLD.

Considerations for liver transplantation in deoxyguanosine kinase deficiency: A case series and review of the literature.

BACKGROUND: Deoxyguanosine kinase (DGUOK) deficiency is a rare mitochondrial disorder characterized by early onset liver failure and varying degrees of neurologic dysfunction. Patients typically present during infancy with progressive hepatic dysfunction leading to liver failure, which can precede neurologic deterioration. Outcomes posttransplantation are historically worse than average and the role of liver transplantation remains controversial. These factors, in combination with the increasing number of patients being diagnosed via molecular genetic testing, may impede waitlist access. METHODS: We report our single-center experience with three patients with DGUOK deficiency, all of whom were considered for transplant. We review the current literature regarding management and discuss the role of liver transplantation in DGUOK deficiency-associated liver failure. RESULTS: Two patients presented with hypoglycemia, conjugated hyperbilirubinemia, and lactic acidosis within the first week of life, were diagnosed with DGUOK deficiency prior to 2 months of age and had severe neurologic involvement. The third patient presented in later infancy was diagnosed with DGUOK deficiency at 18 months of age and had minimal neurologic involvement. All three patients were considered for transplant, though only two patients were listed. All three died from complications of end-stage liver failure prior to liver transplantation between the ages of 5-20 months. CONCLUSION: Selection for liver transplantation in DGUOK deficiency is complex, requiring a multidisciplinary team approach. Recent data suggest that liver transplantation can be successful in select patients with absent or mild neurologic manifestations. National databases reporting long-term outcomes posttransplantation are needed.

Cystic Fibrosis-Associated Gastrointestinal Disease in Neonates.

See Bonus NeoBriefs videos and downloadable teaching slides Gastrointestinal complications of cystic fibrosis (CF) are often the earliest manifestations of disease and contribute to significant morbidity and mortality. Early diagnosis of CF is paramount, as early intervention has been associated with improved long-term pulmonary and nutritional outcomes. In this review, we describe common gastrointestinal, pancreatic, hepatic, and nutritional manifestations of CF in neonates to aid clinicians in diagnosing and managing the earliest gastrointestinal manifestations of CF. Furthermore, we discuss how the use of CFTR-targeted therapies by pregnant and/or breastfeeding persons may affect CF diagnosis in newborns and their potential impact on halting or reversing CF disease progression.

Sirolimus for management of GI bleeding in blue rubber bleb nevus syndrome: A case series.

Blue rubber bleb nevus syndrome (BRBNS) commonly presents with anemia from bleeding gastrointestinal (GI) vascular malformations. Management is highly variable, as no consensus guidelines for medical treatment currently exist. Sirolimus has been used in BRBNS to decrease GI bleeding and seems well tolerated, though questions remain regarding dosing, duration of therapy, and adverse effects. Here, we report our single-center experience of four pediatric patients with BRBNS who were successfully treated with sirolimus and review the existing literature regarding sirolimus for treatment of GI bleeding in BRBNS. Further prospective studies are needed to establish optimal dosage, drug monitoring, and duration.

Delivery of custom-purposed colloidal nanocrystals to cancer cells.

Colloidal inorganic nanocrystals are abound with magnetic, luminescent and plasmonic properties that are attractive for medical diagnostics and therapy. Our group, among others, have been interested in conferring nanocrystals, by design, with new capabilities that are not possible with conventional materials approaches. Two areas where the fruits of these efforts are paying dividends are in their implementation as in vivo imaging probes and as biosensors that dynamically respond to the local chemical or physical environment in cells and tissues. For applications in medical imaging, nanocrystal probes with unusual shapes are showing exceptional promise over existing technologies, while for environment-responsive probes, a hybrid approach involving tailored organic coatings is being implemented alongside the nanocrystals for the realization of dynamic, information-rich optical outputs.