C-reactive protein in patients on chronic hemodialysis with different techniques and different membranes

Premature Aging in Chronic Kidney Disease: The Outcome of Persistent Inflammation beyond the Bounds

Over the last hundred years, life expectancy in developed countries has increased because of healthier living habits and the treatment of chronic pathologies causing premature aging. Aging is an inexorable, time-dependent, multifactorial process characterized by a series of progressive and irreversible physiological changes associated with loss of functional, psychological, and social capabilities. Numerous factors, such as oxidative stress, inflammation, and cellular senescence, and an irreversible geriatric syndrome known as frailty, contribute to human body deterioration in aging. The speed of aging may differ between individuals depending on the presence or absence of multiple factors (genetic and/or environment) and the subsequent misbalance of homeostasis, together with the increase of frailty, which also plays a key role in developing chronic diseases. In addition, pathological circumstances have been reported to precipitate or accelerate the aging process. This review investigated the mechanisms involved in the developing pathologies, particularly chronic kidney disease, associated with aging.

Seroprevalence of a "new" bacterium, Simkania negevensis, in renal transplant recipients and in hemodialysis patients

Background

Simkania negevensis is an obligate intracellular bacterium belonging to the family Simkaniaceae in the Chlamydiales order. It is considered an ubiquitous microorganism and aquatic environments may be involved as a source of infection for humans. It was just isolated in samples from domestic water supplies and from mains water supplies, like spa water or swimming pool water, confirming its ability to resist to the common chlorination treatments. Evidence indicates a possible role of the microorganism in respiratory tract infections, in gastroenteric disorders and in the pathogenesis of cardiovascular disease, furthermore it has hypothesized that it could play a role in lung transplant rejection. Prevalence and possible effects in nephrology are unknown.

Methods

We examined the occurrence of Simkania negevensis in two differents populations, both characterized by a high susceptibility to infectious complications: 105 hemodialysis patients, 105 renal transplant recipients and 105 healthy subjects through the IgG and IgA response to Simkania negevensis in their sera. Serum antibodies to Simkania negevensis were detected by a homemade ELISA performed according to the Kahane’s protocol. Furthermore water samples from hemodialytic circuit were collected, to evaluate Simkania negevensis resistance to usual treatment of disinfection.

Results

Our results were unexpected, showing a higher seroprevalence of antibodies against Simkania negevensis in the hemodialysis patients, compared to renal transplant patients (IgG 22% vs 9% - IgA 9% vs 3%). S. negevensis was isolated in all water samples analyzed.

Conclusions

Our study detected for the first time the occurrence of S. negevensis in hemodialysis and in renal transplant patients. Our findings suggest that water used in hemodialysis could be one of the possible sources of S. negevensis infection, without clinical involvement risk for patients.

Association between depression and inflammatory/anti-inflammatory cytokines in chronic kidney disease and end-stage renal disease patients: a review of literature

Depression is a common psychiatric disorder in patients with advanced chronic kidney diseases (CKDs). Strong correlation has been reported between depression and patients' morbidity and mortality among dialysis patients. On the contrary, chronic inflammation may be a major contributor to morbidity and mortality in these patients. Elevated plasma levels of proinflammatory cytokines, especially C-reactive protein and interleukin (IL)-6, have been correlated with cardiovascular events, hospitalization, and all-cause and cardiovascular-associated mortality in dialysis patients. Studies suggested that inflammation-mediated atherosclerotic cardiovascular diseases are the possible reasons for depression-induced mortality among patients without renal diseases. Several studies found significant elevations in circulating levels of proinflammatory cytokines, particularly IL-6 and tumor necrosis factor-α, in patients with major depression. Furthermore, depressive mood and behaviors, including sadness and suicidal ideation, were observed in patients who received repeated injections of recombinant cytokines. A thorough literature review indicates that while depressive symptoms and elevated inflammatory cytokine levels coexist in CKD and dialysis patients, their association is uncertain. Depression seems to be more associated with elevated serum levels of IL-6 than other cytokines in these patients. Further studies are needed to clarify the possibility of a causal relationship between inflammation and depressive symptoms in CKD and dialysis patients.

Cardiovascular Biomarkers in Chronic Kidney Disease

Cardiovascular morbidity and mortality are markedly increased in chronic renal failure patients. Although it cannot be regarded as a cardiovascular disease risk equivalent, kidney dysfunction is considered an independent predictor of increased cardiovascular risk that increases with deteriorating kidney function. The association is a very complex one, and the term cardiorenal syndrome is now widely used. Cardiovascular disease in chronic kidney disease patients usually manifests as ischemic heart disease (in the form of angina, acute coronary syndrome or sudden cardiac death), cerebrovascular disease, peripheral vascular disease, and congestive heart failure. Vascular disease includes atherosclerosis and vascular calcifications, and cardiomyopathy comprises left ventricular hypertrophy, cardiac fibrosis and left ventricular systolic and diastolic dysfunction. In addition to the well-established traditional risk factors such as hypertension, hyperlipidemia, insulin resistance and diabetes mellitus, the association is supported by synergistic action of non-traditional risk factors such as excessive calcium-phosphorus load, hyperparathyroidism, anemia, hemodynamic overload, malnutrition, inflammation, hyperhomocysteinemia, altered nitric oxide synthase and increased oxidative stress. This paper summarizes the current understanding of the significance of specific uremic retention solutes, natriuretic peptides, biochemical markers of disorders in calcium-phosphorus homeostasis, systemic inflammation, oxidative stress, and dyslipidemia.

Inflammation and oxidative stress in patients on hemodiafiltration

BACKGROUND

Chronic inflammation and oxidative stress are common features in hemodialysis patients. However, research results on the long-term influence of hemodiafiltration (HDF) on oxidative stress and inflammation are limited.

METHODS

We studied changes of inflammatory and oxidative stress biomarkers in 9 stable patients on post-dilution HDF for 9 months. Total antioxidant capacity (TAC), reactive oxygen metabolites (d-ROMs) and superoxide dismutase (SOD) measured by spectrophotometry were used as oxidative stress biomarkers. High-sensitivity CRP (hs-CRP) and IL-6 measured by ELISA were used as inflammation biomarkers.

RESULTS

d-ROMs showed significant reduction at 3 months (323.0 +/- 81.9 vs. 275.0 +/- 62.0 U, p < 0.008) and remained low (267.9 +/- 45.8 U) to the end of the study. At the end of the study there was a significant increase in TAC levels (1.3 +/- 0.1 vs. 1.4 +/- 0.1 mmol/l, p < 0.03), while SOD rise did not reach statistical significance (13.1 +/- 9.8 vs. 18.7 +/- 9.4 U/ml, p = 0.06). hs-CRP values at the end of the study decreased significantly (16.3 +/- 11.4 vs. 6.0 +/- 5.1 microg/ml, p < 0.02), while IL-6 levels showed a non-significant reduction (16.9 +/- 9.3 vs. 12.0 +/- 7.3 pg/ml, p = 0.2).

CONCLUSION

Our results suggest that post-dilution HDF for 9 months suppresses oxidative stress by rapid lowering of d-ROMs and improves antioxidant capacity by increasing TAC, while it reduces inflammation by decreasing hs-CRP.