Residual Renal Function in Hemodialysis and Inflammation

Abstract

Residual renal function (RRF) has an important effect on uremic toxin clearance, on volume control, on quality of life, and on mortality. In patients with chronic kidney disease (CKD), microinflammation with an increased percentage of CD14 /CD16 inflammatory monocytes has been reported, even with no clinical evidence of inflammation. No correlation has been established between these and RRF in hemodialysis (HD) patients. Our objective was to assess the relationship between RRF and the inflammatory parameters in HD patients. Cross-sectional observational study was carried out on 69 adult patients on chronic HD for at least 6 months, from which demographic, analytic and HD-technique data were collected and the following were measured: (i) RRF with average urea and creatinine clearance ((CCr + CU)/2) in 24-h urine (if >1 mL/min and diuresis >100 mL/day, RRF was considered); (ii) Inflammation through biochemical parameters (C-reactive protein, β microglobulin, albumin) and monocyte subpopulations in peripheral blood. The average age was 70.9 [40-88] years old; 38 (55.1%) were male; and 25 (36.2%) were diabetic. 43.5% (30/69) presented RRF, with an average of ((CCr + CU)/2): 1.8 (2.6) mL/min and diuresis: 454.5 (569) mL /24 h. Patients with RRF presented lower concentrations of C-reactive protein (6.2 vs 21.4 mg/L) (P = 0.038) and a lower percentage of non-classical CD14 /CD16 monocytes (14.6 vs. 28.3%, P = 0.02). In our study, patients with RRF present lower concentrations of inflammatory parameters, which is another reason why its preservation is an essential objective in HD.

The importance of residual kidney function in haemodialysis patients

“…Patients with KRU < 0.5 mL/min had significantly higher β2M levels than those with KRU of 0.5–1 mL/min (28.2 ±6.2 vs 23.1 ±4.6 mg/L, P < 0.001), suggesting that even low levels of RKF may be beneficial. Similar results were reported in another study where patients with RKF were found to have significantly lower levels of β2M …”

“…A cross‐sectional observational study by de Sequera et al . found that higher RKF was associated with lower levels of inflammatory parameters . A lower percentage of CD14+/CD16++ inflammatory monocytes (14.6% vs 28.3%, P = 0.02) and lower concentrations of C‐reactive protein (CRP) (6.2 vs 21.4 mg/L, P = 0.038) were found in patients with KRU >1 mL/min and diuresis >100 mL/day.…”

Predicting 3‐year mortality based on the tumor necrosis factor alpha concentration in low‐flux hemodialysis patients

“…The results of our study, as well as those of Yang and several other authors, confirm that in maintenance HD patients, the concentration of the inflammatory markers such as hs-CRP, IL-6, and TNF-α were significantly lower than that of patients with residual renal function. 16,17 Our results are also consistent with Yang's and Vanitha's results, and high serum TNF-α concentration in HD patients was common, but our TNF-α level was higher than the results of the other studies. However, this result requires further explanation.…”

Subjective global assessment of nutrition, dialysis quality, and the theory of the scientific method in Nephrology practice

“…54 Moreover, persisting hypervolemia leads to high ultrafiltration rates with increased risk for hemodynamic instability during dialysis 50 resulting in intra-dialytic tissue hypoxia in the gut, in the myocardium, in the brain and elsewhere. 50,53,[55][56][57][58] The propensity to low-degree inflammation seems to be also associated with residual renal function 59 probably partly due to the potential contribution of the latter to volume control. Additional mechanisms for the development of chronic inflammation on hemodialysis may include oxidative and carbonyl stress, impaired pro-inflammatory cytokine clearance, comorbidities, and dialysis-related factors such as bio-incompatibility, water quality, and vascular access type.…”