Associations of Kidney Functional Magnetic Resonance Imaging Biomarkers with Markers of Inflammation in Individuals with Chronic Kidney Disease.

BACKGROUND: Greater fibrosis and decreased oxygenation may amplify systemic inflammation, but data on the associations of kidney functional magnetic resonance imaging (fMRI) measurements of fibrosis (apparent diffusion coefficient [ADC]) and oxygenation (relaxation rate [R2*]) with systemic markers of inflammation are limited. METHODS: We evaluated associations of baseline kidney fMRI-derived ADC and R2* with baseline and follow-up serum interleukin-6 (IL-6) and C-reactive protein (CRP) in 127 participants from the COMBINE trial, a randomized, 12-month trial of nicotinamide and lanthanum carbonate vs. placebo in individuals with CKD stages 3-4. Cross-sectional analyses of baseline kidney fMRI biomarkers and markers of inflammation used multivariable linear regression. Longitudinal analyses of baseline kidney fMRI biomarkers and change in markers of inflammation over time used linear mixed effects models. RESULTS: Mean±SD eGFR, ADC, and R2* were 32.2±8.7 ml/min/1.73m2, 1.46±0.17 x10-3 mm2/s, and 20.3±3.1 s-1, respectively. Median [IQR] IL-6 and CRP were 3.7 [2.4-4.9] pg/mL and 2.8 [1.2-6.3] mg/L. After multivariable adjustment, IL-6 and CRP were 13.1% and 27.3% higher per 1 SD decrease in baseline cortical ADC. Baseline cortical R2* did not have a significant association with IL-6 or CRP. Mean annual IL-6 and CRP slopes were 0.98 pg/mL per year and 0.91 mg/L per year, respectively. Baseline cortical ADC and R2* did not have significant associations with change in IL-6 or CRP over time. CONCLUSIONS: Lower cortical ADC, suggestive of greater fibrosis, was associated with higher systemic inflammation. Baseline kidney fMRI biomarkers did not associate with changes in systemic markers of inflammation over time.

Influence of peritoneal dialysis catheter type on complications and long-term outcomes: an updated systematic review and meta-analysis.

BACKGROUND: There is currently no consensus regarding the optimal type of peritoneal dialysis catheter (PDC). We compared the outcomes of PDCs according to the number of cuffs, intercuff and intraperitoneal segment shape, and presence of a weighted tip. METHODS: A systematic review of the literature was performed using the MEDLINE and Cochrane Library databases (end-of-search date: October 16th, 2019). We included studies comparing double-cuff vs. single-cuff, swan-neck vs. straight-neck, coiled-tip vs. straight-tip, and weighted vs. non-weighted PDCs for the outcomes of interest. We performed meta-analyses using the random-effects model. We assessed the risk of bias using the Newcastle-Ottawa scale and the Cochrane Collaboration's Tool. RESULTS: In total, 38 studies were identified, of which 20 were randomized controlled trials (RCTs) and 18 were observational studies. No statistically significant differences were detected between double-cuff vs. single-cuff, swan-neck vs. straight-neck, and coiled-tip vs. straight tip PDCs in any of the outcomes of interest. Weighted catheters were associated with significantly lower rates of tunnel infection (relative risk [RR] 0.52, 95% confidence interval [CI] 0.31-0.95, p = 0.03), migration (RR 0.07, 95% CI 0.03-0.16, p < 0.001), drainage failure (RR 0.62, 95% CI 0.39-0.96, p = 0.03), cuff extrusion (RR 0.40, 95% CI 0.21-0.74, p < 0.001), and complication-related removal (RR 0.53, 95% CI 0.44-0.64, p < 0.001). DISCUSSION: Among the different types of PDCs, weighted catheters result in lower complication rates and superior long-term outcomes compared to non-weighted catheters. Other aspects of the catheter design do not significantly affect PDC outcomes. PROTOCOL REGISTRATION: PROSPERO 2020 CRD42020158177.

IgG4-related tubulointerstitial nephritis associated with chronic lymphocytic leukemia.

BACKGROUND: Tubulointerstitial nephritis (TIN) is typically seen in association with drug exposure and infection or in autoimmune diseases such as Sjogren's syndrome or systemic lupus erythematosis. The recently described IgG4-related systemic diseases can affect many organ systems including the kidney and typically respond to corticosteroid treatment. CASE: We present a case of IgG4-related TIN in a patient with concomitant chronic lymphocytic leukemia. To our knowledge, IgG4-related TIN has not been associated with any hematological disorder such as chronic lymphocytic leukemia.
 CONCLUSION: We propose that all kidney biopsies with significant plasma cell infiltrate should be stained for IgG4 as response to treatment is common.