Photo Credit: Nadezhda Buravleva

The following is a summary of “Associations of Kidney Functional Magnetic Resonance Imaging Biomarkers with Markers of Inflammation in Individuals with CKD,” published in the May 2024 issue of Nephrology by Trujillo et al.

More fibrosis and less oxygenation may increase overall inflammation, but not much data is available on how kidney function magnetic resonance imaging (fMRI) measurements of fibrosis (apparent diffusion coefficient [ADC]) and oxygenation relaxation rate ([R2^*]) relate to inflammation.

Researchers conducted a retrospective study exploring the correlation between kidney fMRI markers of fibrosis and oxygenation with inflammation.

They investigated the relationship between fMRI-derived ADC and R2^* with baseline and follow-up serum IL-6 and CRP in individuals with CKD stages 3-4. Data from 127 participants in the CKD optimal management with binders and nicotinamide trial was analyzed. The trial compared the effects of nicotinamide and lanthanum carbonate to a placebo over 12 months. Multivariable linear regression was used to assess associations between baseline kidney fMRI biomarkers and levels of inflammatory markers. Additionally, linear mixed-effects models were employed to examine how baseline kidney fMRI relates to changes in inflammatory markers over the year.

The result showed average ± SD values for eGFR, ADC, and R2^* were 32.2 ± 8.7 ml/min per 1.73 m², 1.46 ± 0.17 × 10^-3 mm²/s, and 20.3 ± 3.1 s^-1, respectively. Median (IQR) levels of IL-6 and CRP were 3.7 (2.4–4.9) pg/ml and 2.8 (1.2–6.3) mg/L. After adjusting for multiple variables, SD decrease in baseline cortical ADC was linked to 13.1% and 27.3% higher levels of IL-6 and CRP, respectively. Baseline cortical R2^* showed no correlation with IL-6 or CRP. The average annual increase in IL-6 and CRP was 0.98 pg/ml and 0.91 mg/L, respectively. No significant associations were observed between baseline cortical ADC and R2^* and changes in IL-6 or CRP over time.

Investigators concluded that lower cortical ADC, indicating greater fibrosis, correlated with higher systemic inflammation, while baseline kidney fMRI biomarkers did not predict changes in systemic inflammation over time.

Source: journals.lww.com/kidney360/fulltext/2024/05000/associations_of_kidney_functional_magnetic.9.aspx