The renal catabolic pathways of cytokines

Profile of Urinary Cytokines in Kawasaki Disease: Non-Invasive Markers

This cohort study aimed to investigate urinary cytokines expression to help identify a less invasive method of cytokine detection for Kawasaki disease (KD). Patients with confirmed KD were recruited. Patients with fever or urinary tract infection (UTI) were enrolled as control groups. Urinary samples were collected before and 3 days after intravenous immunoglobulin (IVIG) treatment. The levels of cytokines were detected by MILLPLEX^® MAP human multiplex assay. All cytokines, i.e., epidermal growth factor (EGF), interferon (IFN)-γ, interleukin (IL)-1β, IL-2, IL-4, IL-5, IL-6, IL-8, IL-9, IL-10, IL-13, IL-17A, IL-33, interferon-gamma-induced protein (IP)-10, macrophage inflammatory protein (MIP)-1β, tumor necrosis factor (TNF)-α, and vascular endothelial growth factor (VEGF) except monocyte chemoattractant protein (MCP)-1 were significantly higher in the KD group, compared with the fever-control (FC) group, whereas the expressions of IFN-γ, IL-1β, IL-6, IL-8, IL-17A, IL-33, MCP-1, MIP-1β, and TNF-α were significantly lower in the urine of KD patients, as compared with the UTI group. The expressions of EGF, IFN-γ, IL-8, IL-13, and IL-17A were higher in the urine of KD patients than in the FC group, whereas the level of IL-1β was lower in KD than in the UTI group after age adjustment by logistic regression. Levels of IL-6, IL-8, IL-13, IP-10, and MCP-1 were significantly higher in the pre-IVIG urine of KD patients than in the post-IVIG treatment group. Additionally, urine IL-4 and blood C-reactive protein were higher in the KD group with coronary artery lesion (CAL) than in the non-CAL group. Results of this study provide a new view of urinary cytokine expression in the disease progress of KD, which may help clinicians to predict and prevent morbidity early and non-invasively.

Cytokine phenotype, genotype, and renal outcomes at cardiac surgery

BACKGROUND

Cardiac surgery modulates pro- and anti-inflammatory cytokine balance involving plasma tumour necrosis factor alpha (TNFα) and interleukin-10 (IL-10) together with urinary transforming growth factor beta-1 (TGFβ1), interleukin-1 receptor antagonist (IL1ra) and tumour necrosis factor soluble receptor-2 (TNFsr2). Effects on post-operative renal function are unclear. We investigated if following cardiac surgery there is a relationship between cytokine (a) phenotype and renal outcome; (b) genotype and phenotype and (c) genotype and renal outcome. Since angiotensin-2 (AG2), modulates TGFβ1 production, we determined whether angiotensin converting enzyme insertion/deletion (ACE I/D) genotype affects urinary TGFβ1 phenotype as well as renal outcome.

METHODS

In 408 elective cardiac surgery patients we measured pre- and 24 h post-operative urinary TGFβ-1, IL1ra and TNFsr2 and pre- and 2 h post-operative plasma TNFα and IL-10. Post-operative responses were compared for each cytokine in patients grouped according to presence or absence of renal dysfunction defined as a drop from baseline eGFR of greater than 25% (as calculated by the method of modification of diet in renal disease (MDRD)) occurring (1) within the first 24 and (2) 48 postoperative hours (early renal dysfunction), (3) on the fifth postoperative day (late renal dysfunction) or (4) at any time throughout the 5 day postoperative period (early and late combined). Patient genotype was determined for TNF/G-308A, TGFβ1-509 C/T, IL10/G-1082A and ACE I/D.

RESULTS

Post-operative plasma IL-10 and urinary TGFβ1 responses were significantly higher in patients who developed early renal dysfunction. IL1ra and TNFsr2 responses were significantly lower 24h post-operatively in patients who developed late renal dysfunction. Genotype did not alter cytokine phenotype or outcome. CONCLUSIONS/INFERENCES: Cytokine profiling may help predict early and late renal dysfunction. Genotypes studied did not alter phenotype or outcome.

Amelioration of renal ischaemia-reperfusion injury by synthetic oligopeptides related to human chorionic gonadotropin

BACKGROUND

We have previously reported that small synthetic oligopeptides related to human beta-chorionic gonadotropin (beta-hCG) can reduce inflammation. Here we investigated whether such oligopeptides can reduce renal ischaemia-reperfusion injury in the mouse.

METHODS

Ten different oligopeptides were administered 1 min before induction of renal ischaemia and 1 min before reperfusion.

RESULTS

Survival at 72 h post-reperfusion was significantly higher in mice treated with oligopeptides MTRV, LQG, VLPALPQ or AQGV as compared to placebo-treated mice. Some oligopeptides were more effective than others. AQGV completely prevented mortality and best preserved kidney function. Next, AQGV was tested in a dose-escalating study in a range of 0.3-30 mg/kg. A survival gain was observed with all doses. Improvement of kidney function was observed from 1 mg/kg. Highest survival and best preserved kidney function were observed at 3 and 10 mg/kg. Upon treatment with AQGV, a significantly lower influx of neutrophils was found, apoptosis was decreased, whereas tubular epithelial cell proliferation was significantly increased at 24 h post-reperfusion. Serum levels of TNF-alpha, INF-gamma, IL-6 and IL-10 were significantly decreased at 24 h post-reperfusion. E-selectin mRNA levels in kidneys were significantly decreased at 6 h post-reperfusion. AQGV did not reduce mortality when treatment was started after reperfusion.

CONCLUSIONS

This study shows that small oligopeptides related to the primary structure of beta-hCG, especially AQGV, are promising potential drugs for preventing the development of renal ischaemia-reperfusion injury.

Acute renal failure after bilateral nephrectomy is associated with cytokine-mediated pulmonary injury

Clinical studies demonstrate that acute renal failure (ARF) is associated with increased mortality, which may be due to pulmonary complications. ARF may affect the lung via increased renal production or impaired clearance of mediators of lung injury, such as proinflammatory cytokines. Bilateral nephrectomy is a method to examine directly the deleterious systemic effects of absent renal clearance in ARF without the confounding effects that are associated with ischemia-reperfusion injury (e.g., ischemic ARF) or systemic toxicity (e.g., cisplatin-induced ARF). This study contrasts the effects of ischemic ARF and bilateral nephrectomy on serum cytokines and lung injury. It demonstrates that the acute absence of kidney function after both ischemic ARF and bilateral nephrectomy is associated with an increase in multiple serum cytokines, including IL-6 and IL-1beta, and that the cytokine profiles were distinct. Lung injury after ischemic ARF and bilateral nephrectomy was similar and was characterized by pulmonary vascular congestion and neutrophil infiltration. For investigation of the role of proinflammatory cytokines in pulmonary injury after ARF, the anti-inflammatory cytokine IL-10 was administered before bilateral nephrectomy. IL-10 treatment improved pulmonary architecture and was associated with a reduction in inflammatory markers, including bronchoalveolar lavage fluid total protein, pulmonary myeloperoxidase activity (a biochemical marker of neutrophils), and the chemokine macrophage inflammatory protein 2. These data demonstrate for the first time that the acute absence of kidney function results in pulmonary injury independent of renal ischemia and highlight the critical role of the kidney in the maintenance of serum cytokine balance and pulmonary homeostasis.

Is kidney function altered by the duration of cardiopulmonary bypass?

BACKGROUND

Cardiopulmonary bypass (CPB) is considered responsible for kidney damage. By using sensitive markers of kidney damage we assessed whether the length of CPB influences kidney function.

METHODS

In a prospective study, 50 consecutive cardiac operation patients with CPB times of less than 70 minutes were compared with 50 consecutive patients showing CPB times of more than 90 minutes. Aside from creatinine clearance and fractional excretion of sodium, urine concentrations of N-acetyl-beta-D-glucosaminidase, alpha1-microglobulin, glutathione transferase-pi, and glutathione transferase-alpha were measured after induction of anesthesia at the end of the operation, and on the first and second postoperative days in the intensive care unit.

RESULTS

CPB times were 58 +/- 12 minutes and 116 +/- 18 minutes, respectively. Hemodynamics, volume replacement, and use of catecholamines during cardiopulmonary bypass (CPB) were without significant differences between groups. Concentrations of all kidney-specific proteins increased significantly after CPB, showing the highest significant increases in the CPB more than 90 minutes group (eg, glutathione transferase-alpha CPB > 90 minutes from 3.0 +/- 1.0 to 12.9 +/- 2.9 microg/L; glutathione transferase-alpha CPB < 70 minutes from 2.4 +/- 0.5 to 5.5 +/- 1.2 microg/L). By the second postoperative day, urine concentrations of kidney-specific proteins had returned to almost baseline in the CPB less than 70 minutes patients, but remained slightly elevated in the other group.

CONCLUSIONS

Patients with CPB times more than 90 minutes showed more pronounced kidney damage than patients with CPB times less than 70 minutes as assessed by sensitive kidney-specific proteins. Whether patients with preexisting renal dysfunction undergoing prolonged CPB times would profit from renal protection strategies needs to be elucidated.