Mass spectrometric study of stone matrix proteins of human bladder stones

Inflammatory factors and the risk of urolithiasis: a bidirectional Mendelian randomization study

Background

Urolithiasis is a prevalent condition encountered in urology. Over the past decade, its global incidence has been on an upward trajectory; paired with a high recurrence rate, this presents considerable health and economic burdens. Although inflammatory factors are pivotal in the onset and progression of urolithiasis, their causal linkages remain elusive.

Method

Mendelian randomization (MR) is predicated upon genome-wide association studies (GWASs). It integrates bioinformatics analyses to reveal causal relationships between exposures and outcomes, rendering it an effective method with minimized bias. Drawing from a publicly accessible GWAS meta-analysis comprising 8,293 samples, we identified 41 genetic variations associated with inflammatory cytokines as instrumental variables. Outcome data on upper urinary tract stones, which included renal and ureteral stones (9,713 cases and 366,693 controls), and lower urinary tract stones, including bladder and urethral stones (1,398 cases and 366,693 controls), were derived from the FinnGen Consortium R9 dataset. By leveraging the bidirectional MR methodology, we aimed to decipher the causal interplay between inflammatory markers and urolithiasis.

Results

Our study comprehensively elucidated the association between genetic inflammatory markers and urolithiasis via bidirectional Mendelian randomization. Post-MR analysis of the 41 genetic inflammation markers revealed that elevated levels of circulating interleukin-2 (IL-2) (OR = 0.921, 95% CI = 0.848-0.999) suggest a reduced risk for renal stone disease, while heightened stem cell growth factor beta (SCGF-β) (OR = 1.150, 95% CI = 1.009-1.310) and diminished macrophage inflammatory protein 1 beta (MIP-1β) (OR = 0.863, 95% CI = 0.779-0.956) levels suggest an augmented risk for lower urinary tract stones. Furthermore, renal stone disease appeared to elevate IL-2 (β = 0.145, 95% CI = 0.013-0.276) and cutaneous T cell-attracting chemokine (CTACK) (β = 0.145, 95% CI = 0.013-0.276) levels in the bloodstream, whereas lower urinary tract stones were linked to a surge in interleukin-5 (IL-5) (β = 0.142, 95% CI = 0.057-0.226), interleukin-7 (IL-7) (β = 0.108, 95% CI = 0.024-0.192), interleukin-8 (IL-8) (β = 0.127, 95% CI = 0.044-0.210), growth regulated oncogene alpha (GRO-α) (β = 0.086, 95% CI = 0.004-0.169), monokine induced by interferon-gamma (MIG) (β = 0.099, 95% CI = 0.008-0.191) and macrophage inflammatory protein 1 alpha (MIP-1α) (β = 0.126, 95% CI = 0.044-0.208) levels.

Conclusion

These discoveries intimate the instrumental role of IL-2 in the onset and progression of upper urinary tract stones. SCGF-β and MIP-1β influence the development of lower urinary tract stones. Urolithiasis also impacts the expression of cytokines such as IL-2, CTACK, IL-5, IL-7, IL-8, GRO-α, MIG, and MIP-1α. There is a pressing need for further investigation to ascertain whether these biomarkers can be harnessed to prevent or treat urolithiasis.

Metabolic syndrome, inflammation and lower urinary tract symptoms: possible translational links

BACKGROUND

Epidemiological data suggest that lower urinary tract symptoms (LUTSs) may be associated with metabolic syndrome (MetS). Inflammation has been proposed as a candidate mechanism at the crossroad between these two clinical entities. The aim of this review article is to evaluate the role of MetS-induced inflammation in the pathogenesis and progression of LUTS.

METHODS

A systematic review was conducted using the keywords 'metabolic syndrome and lower urinary tract symptoms' within the title search engines including PubMed, Web of Science and the Cochrane Library for relevant research work published between 2000 and January 2015. The obtained literature was reviewed by the primary author (QH) and was assessed for eligibility and standard level of evidence.

RESULTS

Total of 52 articles met the eligibility criteria. On the basis of database search during the past 15 years and our systematic review of prospective and retrospective cohorts, case-control trials, observational studies and animal data identified a possible link between MetS-induced inflammation and LUTS including BPH, bladder outlet obstruction, overactive bladder, urinary incontinence and other possible urinary tract abnormalities.

CONCLUSIONS

There is convincing evidence to suggest that MetS and inflammation could be important contributors to LUTS in men, particularly in the development of BPH. However, the role of MetS-induced inflammation remains unclear in overactive bladder, urinary incontinence and etiology of LUTS progression.