Titus Andrian

Background: kidney transplant recipients are exposed to multiple pathogenic pathways that may alter short and long-term allograft survival. Metabolomic profiling is useful for detecting potential biomarkers of kidney disease with a predictive capacity. This field is still under development in kidney transplantation and metabolome analysis is faced with analytical challenges. We performed a cross-sectional study including stable kidney transplant patients and aimed to search for relevant associations between baseline plasmatic and urinary metabolites and relevant outcomes over a follow-up period of 3 years. Methods: we performed a cross-sectional study including 72 stable kidney transplant patients with stored plasmatic and urinary samples at the baseline evaluation which were there analyzed by nuclear magnetic resonance in order to quantify and describe metabolites. We performed a 3-year follow-up and searched for relevant associations between renal failure outcomes and baseline metabolites. Between-group comparisons were made after classification by observed estimated glomerular filtration rate slope during the follow-up: positive slope and negative slope. Results: The mean estimated GFR (glomerular filtration rate) was higher at baseline in the patients who exhibited a negative slope during the follow-up (63.4 mL/min/1.73 m² vs. 55.8 mL/min/1.73 m², p = 0,019). After log transformation and division by urinary creatinine, urinary dimethylamine (3.63 vs. 3.16, p = 0.027), hippuric acid (7.33 vs. 6.29, p = 0.041), and acetone (1.88 vs. 1, p = 0.023) exhibited higher concentrations in patients with a negative GFR slope when compared to patients with a positive GFR slope. By computing a linear regression, a significant low-strength regression equation between the log 2 transformed plasmatic level of glycine and the estimated glomerular filtration rate was found (F (1,70) = 5.15, p = 0.026), with an R² of 0.069. Several metabolites were correlated positively with hand grip strength (plasmatic tyrosine with r = 0.336 and p = 0.005 and plasmatic leucine with r = 0.371 and p = 0.002). Other urinary metabolites were found to be correlated negatively with hand grip strength (dimethylamine with r = −0.250 and p = 0.04, citric acid with r = −0.296 and p = 0.014, formic acid with r = −0.349 and p = 0.004, and glycine with r = −0.306 and p = 0.01). Conclusions: some metabolites had different concentrations compared to kidney transplant patients with negative and positive slopes, and significant correlations were found between hand grip strength and urinary and plasmatic metabolites.

Vitamin K supplementation has been considered recently as a potential treatment for addressing vascular calcification in chronic kidney disease patients.We conducted a systematic review and meta-analysis to summarize the impact of vitamin K supplementation in dialysis patients. Electronic databases were searched for clinical randomized trials among patients treated with vitamin K. Random effects models were performed and risk of bias was evaluated with Cochrane tools and the search was conducted until 15 of September 2023.Eleven trials comprising 830 patients (both adult and pediatric, mainly hemodialysis) compared vitamin K with different controls: lower doses of vitamin K, standard care or placebo. Vitamin K supplementation had no effect on mortality. Vitamin K administration improved vitamin K levels and led to lower levels of dp-uc-MGP and moderately increased calcium levels [0.18 (0.04–0.32)]. Vitamin K1 proved more potency in reducing dp-uc-MGP [SMD −1.64 (−2.05, −1.23) vs. −0.56 (−0.82, −0.31)] and also raised serum vitamin K levels in comparison with vitamin K2 [5.69 (3.43, 7.94) vs. 2.25 (−2.36, 6.87)]. While it did not have a proved benefit in changing calcification scores [−0.14 (−0.37 ± 0.09)], vitamin K proved to be a safe product. There was some concern with bias.Vitamin K supplementation has no impact on mortality and did not show significant benefit in reversing calcification scores. Vitamin K1 improved vitamin K deposits and lowered dp-uc-MGP, which is a calcification biomarker more than vitamin K2. As it proved to be a safe product, additional randomized well-powered studies with improved treatment regimens are needed to establish the true impact of vitamin K in dialysis patients.

Rates of late allograft loss have improved slowly in the last decades. Well described traditional risk factors that influence allograft survival include cardiovascular events, rejection, infections and post-transplant neoplasia. Here, we critically evaluate the influence of several non-immunological, non-traditional risk factors and describe their impact on allograft survival and cardiovascular health of kidney transplant recipients. We assessed the following risk factors: arterial stiffness, persistent arteriovenous access, mineral bone disease, immunosuppressive drugs residual levels variability, hypomagnesemia, glomerular pathological alterations not included in Banff criteria, persistent inflammation and metabolic acidosis.

Glomerulonephritis associated with infective endocarditis is a form of immune-mediated glomerular injury and frequently presents with acute kidney injury (AKI) and kidney failure [ 1]. Bartonella henselae is a less common cause of endocarditis and occurs in patients with pre-existing valvular disease and cat-exposure. Antineutrophil cytoplasmic antibodies (ANCA) positivity and complement pathway activation in infective endocarditis make diagnosis challenging and treatment choices depend on the autoimmune or infectious origin of the glomerulonephritis [ 2].