Urinary stone disease prevalence and associations in cystic fibrosis

Cystic fibrosis foundation position paper: Redefining the cystic fibrosis care team

Interdisciplinary teams care for people with cystic fibrosis (pwCF) at specialized treatment centers. These teams have laid the foundation for the cystic fibrosis (CF) care model responsible for gains in health outcomes and quality of life within the CF community. However, the landscape of CF care is transforming, invigorated by new technologies, accessibility of cystic fibrosis transmembrane conductance regulator (CFTR) therapies, and increased utilization of telemedicine. In light of these advances, it is appropriate to re-evaluate the CF care team structure. This position paper offers guidance for the structure of a CF care center designed to meet the evolving needs of the CF community. Fundamental to the proposed center structure is recognition of pwCF and their families as integral members of their care teams, underpinning the necessity for shared decision making, awareness of social determinants of health, and active partnership between all healthcare professionals involved in the care of pwCF.

Beneficial roles of gastrointestinal and urinary microbiomes in kidney stone prevention via their oxalate-degrading ability and beyond

Formation of calcium oxalate (CaOx) crystal, the most common composition in kidney stones, occurs following supersaturation of calcium and oxalate ions in the urine. In addition to endogenous source, another main source of calcium and oxalate ions is dietary intake. In the intestinal lumen, calcium can bind with oxalate to form precipitates to be eliminated with feces. High intake of oxalate-rich foods, inappropriate amount of daily calcium intake, defective intestinal transporters for oxalate secretion and absorption, and gastrointestinal (GI) malabsorption (i.e., from gastric bypass surgery) can enhance intestinal oxalate absorption, thereby increasing urinary oxalate level and risk of kidney stone disease (KSD). The GI microbiome rich with oxalate-degrading bacteria can reduce intestinal oxalate absorption and urinary oxalate level. In addition to the oxalate-degrading ability, the GI microbiome also affects expression of oxalate transporters and net intestinal oxalate transport, cholesterol level, and short-chain fatty acids (SCFAs) production, leading to lower KSD risk. Recent evidence also shows beneficial effects of urinary microbiome in KSD prevention. This review summarizes the current knowledge on the aforementioned aspects. Potential benefits of the GI and urinary microbiomes as probiotics for KSD prevention are emphasized. Finally, challenges and future perspectives of probiotic treatment in KSD are discussed.

Bone health outcomes in post-lung transplant patients with cystic fibrosis

BACKGROUND

Osteoporosis is a common comorbidity in patients with cystic fibrosis (CF). Although lung transplantation (LTx) improves quality of life of CF patients, there is little research examining long-term bone health outcomes following LTx in these patients.

METHODS

Data were collected on 59 patients who underwent LTx between 2006 and 2019, including 30 with CF and 29 without CF. We compared baseline characteristics, long-term bone mineral density (BMD) trends, and fracture incidence between the two patient populations, and examined factors associated with post-LTx fractures in CF patients.

RESULTS

Compared with non-CF patients, patients with CF were younger, had lower body mass index, and lower baseline BMD Z-scores at the lumbar spine, femoral neck, and total hip (all p<0.001). BMD at all sites declined in both groups in the first year post-LTx. In subsequent years, CF patients exhibited better BMD recovery relative to pre-transplantation, but continued to have lower BMD post-LTx. Post-transplant fractures occurred in 30% and 34% of CF and non-CF patients, respectively. CF patients who developed fractures after LTx had significantly lower BMD and lower pre-transplantation percent predicted forced expiratory volume in one second (FEV1%).

CONCLUSIONS

Although CF patients exhibit better BMD recovery following LTx compared to their non-CF counterparts, CF patients start with significantly lower pre-LTx BMD and experience a similarly high rate of post-LTx fractures. These findings highlight the unique contribution of the CF disease process to bone health, as well as a clear need for better prevention and treatment of osteoporosis in CF patients before and after LTx.

Antimicrobial Stewardship in Cystic Fibrosis

The chronic airway infection and inflammation characteristic of cystic fibrosis (CF) ultimately leads to progressive lung disease, the primary cause of death in persons with CF (pwCF). Despite many recent advances in CF clinical care, efforts to preserve lung function in many pwCF still necessitate frequent antimicrobial use. Incorporating antimicrobial stewardship (AMS) principles into management of pulmonary exacerbations (PEx) would facilitate development of best practices for antimicrobial utilization at CF care centers. However, AMS can be challenging in CF given the unique aspects of chronic, polymicrobial infection in the CF airways, lack of evidence-based guidelines for managing PEx, limited utility for antimicrobial susceptibility testing, and increased frequency of adverse drug events in pwCF. This article describes current evidence-based antimicrobial treatment strategies for pwCF, highlights the potential for AMS to beneficially impact CF care, and provides practical strategies for integrating AMS programs into the management of PEx in pwCF.

Association Study Between Polymorphic Loci in Cholesterol Metabolism Pathway and Gallstone in the Tibetan Population

Background: The incidence of gallstones in the Tibetan population is increasing rapidly. Previous studies indicated that genetic variation located in the cholesterol metabolism pathway may be associated with the incidence of gallstones.

Methods: By recruiting 132 Tibetan gallstone patients and 52 normal Tibetan controls, we performed next-generation sequencing for 508 genes in the cholesterol metabolism pathway. Additionally, by integrating the sequence data of 41 normal Tibetan subjects in the public database, we finally obtained 93 normal Tibetan controls. Single nucleotide polymorphisms (SNPs) calling were performed by using the GATK pipeline. The quality control criteria for SNPs were: missing rate <0.05; minor allele frequency (MAF) > 0.01; and p value >0.001 in the Hardy-Weinberg Equilibrium (HWE) test. To eliminate the influence of population heterogeneity, Principal Component Analysis (PCA) was carried out by using the smartpca software. Association analyses were performed by Plink software. Multiple tests were adjusted by the false discovery rate (FDR) method.

Results: A total of 2,401 SNPs were obtained by analyzing 508 genes, and 2,011 SNPs left after quality control. After adjusting the eigen vectors, we found that 10 SNPs (SNV05997, rs80145081, rs80005560, rs79074685, rs748546375, rs201880593, rs142559357, rs750769471, rs869789 and rs4072341) were significantly associated with gallstone. Subsequently, by comparing the case group with our control group and the public database control group separately, we further found that the SNP rs869789 was consistently significantly associated with gallstone (p = 9.04 × 10^–3 in cases vs. our controls and 5.73 × 10^–3 in cases vs. public controls, respectively).

Conclusion: By systematically analyzed SNPs in the cholesterol metabolism pathway, we identified one polymorphic locus rs869789 significantly associated with the pathogenesis of gallstone in the Tibetan population. This study will provide clue for further mechanism study of gallstone in the Tibetan population.