Effect of Increased Convection Volume by Mid-Dilution Hemodiafiltration on the Subclinical Chronic Inflammation in Maintenance Hemodialysis Patients

Abstract

Mid-dilution hemodiafiltration (MID) is a dialytic technique that might improve systemic inflammation of patients in chronic hemodialysis (HD) by increasing substitution volumes. To verify this hypothesis, we performed a prospective cross-over study comparing the effect on inflammatory biomarkers of higher convection by MID versus standard convection by post-dilution hemodiafiltration (HDF). Patients under chronic HD were therefore treated by MID and HDF by crossover design. Each treatment period lasted 4 months, with 1 month of wash-out where patients were treated by HD, for a total of 9 months. Primary outcome was the change of serum pre-dialytic C-Reactive Protein (CRP), interleukin 6 (IL-6), IL-1, IL-10, transforming growth factor-β (TGF-β), tumor necrosis factor-α, albumin and pre-albumin. Samples were obtained monthly. Ten HD patients were enrolled (age: 64.9 ± 12.6 years; 70% males; dialytic vintage: 10.6 [2.7–16.2] years). Mean convection volume was 40.1 ± 2.5 L/session in MID and 20.1 ± 2.6 L/session in HDF. A significant reduction of β2-Microglobulin was detected as a result of either treatment. In MID, CRP decreased from 11.3 (3.2–31.0) to 3.1 (1.4–14.4) mg/L (p = 0.007), IL-6 from 12.7 (5.0–29.7) to 8.3 (4.4–14.0) pg/mL (p = 0.003), and TGF-β from 10.6 (7.4–15.6) to 7.4 (5.9–9.3) ng/mL (p = 0.001). A significant reduction of CRP from 8.5 (3.2–31.0) to 4.6 (3.2–31.0) mg/L was also detected in HDF (p = 0.037), whereas no significant reduction of IL-6 (p = 0.147) and TGF-β (p = 0.094) was found. Percentage reduction of IL-6 correlated with mean convective volume in HDF (R = 0.666; p = 0.036) and in MID (R = 0.760; p = 0.020). Therefore, MID and HDF are associated with an attenuation of inflammatory pattern that is correlated with a high convective volume.

Iron Infusion and Induced Hypophosphatemia: The Role of Fibroblast Growth Factor‐23

“…Gan and Zhou conducted a study on FGF23 and Klotho in 180 patients with CKD‐mineral bone disorder. They observed that in HD patients, especially those with secondary hyperparathyroidism, the levels of FGF23 were high and levels of Klotho were low: this predisposed for greater ectopic calcifications, which are known to be typically present in patients in chronic renal diseases even before undergoing dialysis treatment and suggested a significant correlation with increasing volume of the left ventricle and cardiac hypertrophy . The pro‐fibrotic action of FGF23 on the heart has recently been documented, using cardiac autopsies from 24 patients on HD and in vitro studies.…”