Relationships between inflammation, hemodynamic function and RAAS in longstanding type 1 diabetes and diabetic kidney disease

The renin angiotensin aldosterone system (RAAS) is associated with renal disease and inflammation in a diabetes setting, however, little is known about the implicated mechanisms in individuals with long standing diabetes. Accordingly, our aim was to perform an observational study to quantify urinary excretion of inflammatory biomarkers in participants with long standing type 1 diabetes (T1D) (with and without diabetic kidney disease [DKD]) and controls, at baseline and in response to RAAS activation. GFR_INULIN, ERPF_PAH, and 42 urine inflammatory biomarkers were measured in 74 participants with T1D for ≥50 years (21 with DKD and 44 without DKD [DKD resistors]) and 73 healthy controls. Additionally, inflammatory biomarkers were measured before and after an angiotensin II infusion (ANGII, 1 ng∙kg^-1∙min^-1). Significantly lower urinary excretion of cytokines (IL-18, IL-1RA, IL-8), chemokines (MCP1, RANTES) and growth factors (TGF-α, PDGFAA, PDGFBB, VEGF-A) was observed in participants with T1D at baseline compared to controls. Urinary IL-6 was higher in DKD than in DKD resistors in an exploratory analysis unadjusted for multiple comparisons. In T1D only, lower GFR_INULIN correlated with greater excretion of proinflammatory biomarkers (IL-18, IP-10, & RANTES), growth factors (PDGF-AA & VEGFAA), and chemokines (eotaxin & MCP-1). ANGII increased 31 of 42 inflammatory biomarkers in T1D vs controls (p < 0.05), regardless of DKD resistor status. In conclusion, lower GFR and intra-renal RAAS activation were associated with increased inflammation even after longstanding T1D. The increased urinary IL-6 in patients with DKD requires further investigation to determine whether IL-6 is a candidate protective biomarker for prognostication or targeted therapy in DKD.

Early Increased Urinary IL-2 and IL-10 Levels Were Associated With Development of Chronic UTI in a Murine Model

OBJECTIVES

To analyze factors during early stage of urinary tract infection (UTI) that are associated with development of chronic UTI.

METHODS

Mice were inoculated with Uropathogenic Escherichia coli (UPEC) 2 times 24 hours apart. At 1, 3, 7, 10, 14, 21 and 28 days post infection (dpi), urine bacterial loads and voiding behavior (voiding spot assay, VSA) were measured. At 1 and 28 dpi, 32 urine inflammatory cytokines/chemokines were measured using enzyme-linked immunosorbent assay (ELISA). Bladder and kidney cytokines/chemokines were measured on 28 dpi. Mice that had no more than 1 episode of urine bacterial load < 104 colony forming unit/ml during the entire 4 weeks were defined as susceptible to chronic UTI, otherwise, mice were considered resistant.

RESULTS

At 28 dpi, 64.3% mice developed chronic UTI (susceptible group) and 35.7% mice did not (resistant group). Factors at 1 dpi that were predictive of chronic UTI included increased urine IL-2 (OR 11.9, 95%CI 1.1-130.8, P = .043) and increased urine IL-10 (OR 14.0, 95%CI 1.0-201.2, P = .052). At 28 dpi, there were several significant differences between the susceptible vs resistant groups including urine/tissue bacterial loads and certain urine/tissue cytokines/chemokines.

CONCLUSIONS

Higher urine IL-2 and IL-10 at 1 dpi predicted chronic UTI infection in this model. There have been recent publications associating both of these cytokines to UTI susceptibility. Further explorations into IL-2 and IL-10 mediated pathways could shed light on the biology of recurrent and chronic UTI which are difficult to treat.

New Biomarkers in Acute Tubulointerstitial Nephritis: A Novel Approach to a Classic Condition

Acute tubulointerstitial nephritis (ATIN) is an immunomediated cause of acute kidney injury. The prevalence of ATIN among the causes of acute kidney injury (AKI) is not negligible, especially those cases related to certain drugs. To date, there is a lack of reliable non-invasive diagnostic and follow-up markers. The gold standard for diagnosis is kidney biopsy, which shows a pattern of tubulointerstitial leukocyte infiltrate. The urinalysis findings can aid in the diagnosis but are no longer considered sensitive or specific. Atthe present time, there is a rising attentiveness tofinding trustworthy biomarkers of the disease, with special focus in urinary cytokines and chemokines that may reflect kidney local inflammation. Cell-based tests are of notable interest to identify the exact drug involved in hypersensitivity reactions to drugs, manifesting as ATIN. Certain single-nucleotide polymorphisms in HLA or cytokine genes may confer susceptibility to the disease according to pathophysiological basis. In this review, we aim to critically examine and summarize the available evidence on this topic.

Molecular correlates in urine for the obesity and prostatic inflammation of BPH/LUTS patients

PURPOSE

Benign prostatic hyperplasia (BPH) is strongly associated with obesity and prostatic tissue inflammation, but the molecular underpinning of this relationship is not known. Here, we examined the association between urine levels of chemokines/adipokines with histological markers of prostate inflammation, obesity, and lower urinary tract symptoms LUTS in BPH patients.

METHODS

Frozen urine specimens from 207 BPH/LUTS patients enrolled in Nashville Men's Health Study were sent for blinded analysis of 11 analytes, namely sIL-1RA, CXC chemokines (CXCL-1, CXCL-8, CXCL-10), CC chemokines (CCL2, CCL3, CCL5), PDGF-BB, interleukins IL-6, IL-17, and sCD40L using Luminex™ xMAP® technology. After adjusting for age and medication use, the urine levels of analytes were correlated with the scales of obesity, prostate inflammation grade, extent, and markers of lymphocytic infiltration (CD3 and CD20) using linear regression.

RESULTS

sIL-1RA levels were significantly raised with higher BMI, waist circumference and waist-hip ratio in BPH patients after correction for multiple testing (P = 0.02). Men with greater overall extent of inflammatory infiltrates and maximal CD3 infiltration were marginally associated with CXCL-10 (P = 0.054) and CCL5 (P = 0.054), respectively. CCL3 in 15 patients with moderate to severe grade inflammation was marginally associated with maximal CD20 infiltration (P = 0.09), whereas CCL3 was undetectable in men with mild prostate tissue inflammation. There was marginal association of sCD40L with AUA-SI scores (P = 0.07).

CONCLUSIONS

Strong association of sIL-1RA in urine with greater body size supports it as a major molecular correlate of obesity in the urine of BPH patients. Increased urine levels of CXCL-10, CCL5, and CCL3 were marginally associated with the scores for prostate tissue inflammation and lymphocytic infiltration. Overall, elevated urinary chemokines support that BPH is a metabolic disorder and suggest a molecular link between BPH/LUTS and prostatic inflammation.

The urinary cytokine/chemokine signature of renal hyperfiltration in adolescents with type 1 diabetes

OBJECTIVE

Urinary cytokine/chemokine levels are elevated in adults with type 1 diabetes (T1D) exhibiting renal hyperfiltration. Whether this observation extends to adolescents with T1D remains unknown. Our first objective was to determine the relationship between hyperfiltration and urinary cytokines/chemokines in normotensive, normoalbuminuric adolescents with T1D using GFR(cystatin). Our second aim was to determine the relationship between urine and plasma levels of inflammatory biomarkers, to clarify the origin of these factors.

METHODS

Urine and serum cytokines/chemokines (Luminex platform) and GFR(cystatin) were measured in normofiltering (n = 111, T1D-N, GFR<135 ml/min/1.73 m(2)) and hyperfiltering (n = 31, T1D-H, GFR ≥ 135 ml/min/1.73 m(2)) adolescents with T1D (ages 10-16), and in age and sex matched healthy control subjects (HC, n = 59).

RESULTS

We noted significant step-wise increases in urinary cytokine/chemokine excretion according to filtration status with highest levels in T1D-H, with parallel trends in serum analyte concentrations. After adjusting for serum glucose at the time of sampling, differences in urinary cytokine excretion were not statistically significant. Only serum IL-2 significantly differed between HC and T1D (p = 0.0076).

CONCLUSIONS

Hyperfiltration is associated with increased urinary cytokine/chemokine excretion in T1D adolescents, and parallel trends in serum cytokine concentration. The GFR-associated trends in cytokine excretion may be driven by the effects of ambient hyperglycemia. The relationship between hyperfiltration, glycemia, and variations in serum and urine cytokine expression and their impact on future renal and systemic vascular complications requires further study.

Urinary cytokine and chemokine profiles across the menstrual cycle in healthy reproductive-aged women

OBJECTIVE

To assess the utility of urinary cytokines for monitoring reproductive function by considering detection, variation across the menstrual cycle, and relations with hormones.

DESIGN

Longitudinal cohort study.

SETTING

Academic institution.

PATIENT(S)

Healthy, reproductive-aged women with self-reported regular menstrual cycles and at least one observed ovulatory cycle (n = 248).

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Urinary cytokines measured by 30-plex immunoassays in 3,550 biospecimens, and nested random-effects analysis of variance (ANOVA) and marginal structural models used to evaluate variability and relations with hormones.

RESULT(S)

For 24 of 30 evaluated factors, detectable levels were observed in at least 50% of urine samples. Interleukin-6 (IL-6), IL-8, IL-10, IL-15, granulocyte colony stimulating factor (G-CSF), hepatocyte growth factor (HGF), interferon-α (IFN-α), and RANTES (regulated upon activation normal T-cell expressed and secreted) levels varied significantly across the menstrual cycle. The proinflammatory factors IL-1β, IL-6, IL-8, and HGF were 1.5-3 times higher during menses than the late follicular phase. In marginal structural models, IL-1β, IL-6, IL-8 were associated with lower estradiol and progesterone concentrations.

CONCLUSION(S)

Variability during the menstrual cycle and correlations with reproductive hormone levels support a role of cytokines in the menstrual cycle; however, because of the limited variability for most cytokines considered, the utility of urine as a matrix for assessment of inflammation in menstrual cycle function appears limited for clinical purposes.

The effect of aliskiren on urinary cytokine/chemokine responses to clamped hyperglycaemia in type 1 diabetes

AIMS/HYPOTHESIS

Acute clamped hyperglycaemia activates the renin-angiotensin-aldosterone system (RAAS) and increases the urinary excretion of inflammatory cytokines/chemokines in patients with uncomplicated type 1 diabetes mellitus. Our objective was to determine whether blockade of the RAAS would blunt the effect of acute hyperglycaemia on urinary cytokine/chemokine excretion, thereby giving insights into potentially protective effects of these agents prior to the onset of clinical nephropathy.

METHODS

Blood pressure, renal haemodynamic function (inulin and para-aminohippurate clearances) and urinary cytokines/chemokines were measured after 6 h of clamped euglycaemia (4-6 mmol/l) and hyperglycaemia (9-11 mmol/l) on two consecutive days in patients with type 1 diabetes mellitus (n = 27) without overt nephropathy. Measurements were repeated after treatment with aliskiren (300 mg daily) for 30 days.

RESULTS

Before aliskiren, clamped hyperglycaemia increased filtration fraction (from 0.188 ± 0.007 to 0.206 ± 0.007, p = 0.003) and urinary fibroblast growth factor-2 (FGF2), IFN-α2 and macrophage-derived chemokine (MDC) (p < 0.005). After aliskiren, the filtration fraction response to hyperglycaemia was abolished, resulting in a lower filtration fraction after aliskiren under clamped hyperglycaemic conditions (p = 0.004), and none of the biomarkers increased in response to hyperglycaemia. Aliskiren therapy also reduced levels of urinary eotaxin, FGF2, IFN-α2, IL-2 and MDC during clamped hyperglycaemia (p < 0.005).

CONCLUSIONS/INTERPRETATION

The increased urinary excretion of inflammatory cytokines/chemokines in response to acute hyperglycaemia is blunted by RAAS blockade in humans with uncomplicated type 1 diabetes mellitus.

The effect of renal hyperfiltration on urinary inflammatory cytokines/chemokines in patients with uncomplicated type 1 diabetes mellitus

AIMS/HYPOTHESIS

High intraglomerular pressure causes renal inflammation in experimental models of diabetes. Our objective was to determine whether renal hyperfiltration, a surrogate for intraglomerular hypertension, is associated with increased excretion of urinary cytokines/chemokines in patients with type 1 diabetes mellitus.

METHODS

Blood pressure, renal haemodynamic function (inulin and para-aminohippurate clearances for glomerular filtration rate (GFR) and effective renal plasma flow (ERPF), respectively) and urine samples were obtained during clamped euglycaemia in individuals with type 1 diabetes with either hyperfiltration (GFR determined using inulin [GFRINULIN] ≥ 135 ml min⁻¹ 1.73 m⁻², n = 28) or normofiltration (n = 21) and healthy control individuals (n = 18).

RESULTS

Baseline clinical characteristics, dietary sodium and protein intake and blood pressure levels were similar in the diabetic and healthy control groups. In addition, HbA1c levels were similar in the two diabetic groups. As expected baseline GFR was higher in hyperfilterers than either normofiltering diabetic patients or healthy control patients (165 ± 9 vs 113 ± 2 and 116 ± 4 ml min⁻¹ 1.73 m⁻², respectively, p < 0.01). ERPF and renal blood flow were also comparatively higher and renal vascular resistance was lower in hyperfiltering patients (p < 0.01). Hyperfiltering diabetic patients had higher excretion rates for eotaxin, IFNα2, macrophage-derived chemokine, platelet-derived growth factor (PDGF)-AA, PDGF-AB/BB and granulocyte-macrophage colony-stimulating factor (p ≤ 0.01). Urinary monocyte chemoattractant protein (MCP)-1 and RANTES (regulated on activation, normal T expressed and secreted) excretion was also higher in hyperfiltering vs normofiltering diabetic individuals (p < 0.01) and fibroblast growth factor-2, MCP-3 and CD40K excretion was elevated in hyperfiltering diabetic individuals vs healthy controls (p < 0.01).

CONCLUSIONS/INTERPRETATION

Renal hyperfiltration is associated with increased urinary excretion of inflammatory cytokines/chemokines in patients with uncomplicated type 1 diabetes.

Distinct renal pathology and a chemotactic phenotype after enterohemorrhagic Escherichia coli shiga toxins in non-human primate models of hemolytic uremic syndrome

Enterohemorrhagic Escherichia coli cause approximately 1.5 million infections globally with 176,000 cases occurring in the United States annually from ingesting contaminated food, most frequently E. coli O157:H7 in ground beef or fresh produce. In severe cases, the painful prodromal hemorrhagic colitis is complicated by potentially lethal hemolytic uremic syndrome (HUS), particularly in children. Bacterial Shiga-like toxins (Stx1, Stx2) are primarily responsible for HUS and the kidney and neurologic damage that ensue. Small animal models are hampered by the inability to reproduce HUS with thrombotic microangiopathy, hemolytic anemia, and acute kidney injury. Earlier, we showed that nonhuman primates (Papio) recapitulated clinical HUS after Stx challenge and that novel therapeutic intervention rescued the animals. Here, we present detailed light and electron microscopic pathology examination of the kidneys from these Stx studies. Stx1 challenge resulted in more severe glomerular endothelial injury, whereas the glomerular injury after Stx2 also included prominent mesangiolysis and an eosinophilic inflammatory infiltration. Both toxins induced glomerular platelet-rich thrombi, interstitial hemorrhage, and tubular injury. Analysis of kidney and other organs for inflammation biomarkers showed a striking chemotactic profile, with extremely high mRNA levels for IL-8, monocyte chemoattractant protein 1, and macrophage inflammatory protein 1α and elevated urine chemokines at 48 hours after challenge. These observations give unique insight into the pathologic consequences of each toxin in a near human setting and present potential pathways for therapeutic intervention.

Urinary markers of renal inflammation in adolescents with Type 1 diabetes mellitus and normoalbuminuria

AIMS

Patients with the highest albumin:creatinine ratio within the normal range are at an increased risk for developing microalbuminuria. The mechanistic basis for this is unknown, but may be related to renal inflammation. Our goal was to characterize the urinary excretion of cytokines/chemokines in normoalbuminuric adolescents with Type 1 diabetes to determine whether higher range normoalbuminuria is associated with evidence of renal inflammation.

METHODS

Forty-two urinary cytokines/chemokines were measured in subjects who were screened for the Adolescent Type 1 Diabetes Cardio-Renal Intervention Trial. Urinary cytokines/chemokines were compared across low (n = 50), middle (n = 50) or high (n = 50) albumin:creatinine ratio tertile groups.

RESULTS

At baseline, participants in the upper tertile were younger and had shorter diabetes duration compared with the other groups. Other clinical characteristics were similar. Urinary levels of interleukin 6, interleukin 8, platelet-derived growth factor-AA and RANTES differed across albumin:creatinine ratio tertiles, with higher values in patients in the middle and high tertiles compared with the lower tertile (ANCOVA P ≤ 0.01).

CONCLUSIONS

Within the normal albumin:creatinine ratio range, higher urinary albumin excretion is associated with elevated urinary levels of inflammatory markers. Ultimately, this may provide mechanistic insights into disease pathophysiology and stratify the risk of nephropathy in Type 1 diabetes.

Effect of a phytotherapeutic agent, Eviprostat®, on prostatic and urinary cytokines/chemokines in a rat model of nonbacterial prostatitis

BACKGROUND

Chronic inflammation in the prostate has recently been recognized as an important component of the symptom progression of benign prostatic hyperplasia. The objective of this study was to evaluate a range of cytokines/chemokines in prostate tissue and urine to identify markers of prostate inflammation in a prostatitis model and to investigate the effect of a phytotherapeutic agent, Eviprostat®, on these markers.

METHODS

Ten-month-old male Wistar rats were divided into four groups. Nonbacterial prostatitis (NBP) was experimentally induced in groups 2-4 by castration followed by daily subcutaneous injection of 17β-estradiol for 30 days. Control rats were fed a standard diet, while animals in the Eviprostat groups were fed a diet containing 0.05 or 0.1% Eviprostat for 30 days. The levels of cytokines/chemokines in prostate tissue on the 31st day and in urine collected the day before castration and the day before removal of the prostate were determined.

RESULTS

Experimentally induced NBP increased the prostatic levels of the cytokines interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α). The levels of the chemokines CCL2/monocyte chemoattractant protein-1 (MCP-1), CCL3/macrophage inflammatory protein-1α (MIP-1α), CXCL1/CINC-1, CXCL3/CINC-2, and CXCL5/LIX were elevated in both prostate and urine. Eviprostat significantly suppressed the increases in prostate IL-1β, TNF-α and CCL3/MIP-1α and prostatic and urinary CCL2/MCP-1 and CXCL1/CINC-1.

CONCLUSIONS

Chemokines, including CCL2/MCP-1 and CXCL1/CINC-1, were elevated in the prostate and urine of NBP rats, and Eviprostat potently suppressed the increases in CCL2/MCP-1 and CXCL1/CINC-1. These chemokines are therefore candidate diagnostic biomarkers for nonbacterial chronic prostatic inflammation.

Biomarkers in lupus nephritis

Biomarkers have the potential to be useful tools for noninvasively evaluating and managing patients with lupus nephritis. Many candidate biomarkers have been identified, but they require validation in larger cohorts. It is likely that combinations or biomarker profiles, rather than individual markers, will emerge to help better predict the severity of inflammation, the extent of fibrosis, degree of drug responsiveness, and other variables. This approach has the potential to reduce the use of the renal biopsy, improve therapeutic efficacy, and limit toxicity. We predict algorithms based on genotype and biomarkers combined with clinical presentation will emerge to help guide physicians in management. Assays that show the most potential include serum erythrocyte bound complement C4d, interleukin 17, interleukin 23, interferon score/chemokine score ratio, and anti-C1q antibodies. Such urinary biomarkers as fractional excretion of endothelial-1, monocyte chemoattractant protein-1, vascular cell adhesion molecule-1, and TWEAK (tumor necrosis factor-like weak inducer of apoptosis) may also be useful but require validations.

Urine chemokines: biomarkers of human lupus nephritis?

Lupus nephritis is characterized by intrarenal inflammation. Leukocytes trafficking from peripheral blood into affected tissues spaces represent an important factor in the development of many renal diseases. During the past few years has been attributed the crucial role of a family of chemotactic cytokines--the chemokines--in this process. In the course of renal diseases, the infiltration of monocytes/macrophages and T cells into kidneys represent an important role in progressive interstitial fibrosis and the progression of chronic renal failure. In this review, we summarize the in vitro and in vivo data on chemokines and chemokine receptors in kidney diseases, with a special focus on urine chemokine measurement as possible biomarker of human lupus nephritis.

Mycobacterium bovis bacillus Calmette-Guérin (BCG) induces human CC- and CXC-chemokines in vitro and in vivo

Both CC- and CXC-chemokines are known to be potent leucocyte activators and chemoattractants and play important roles in inflammatory responses. However, chemokine response to bacillus Calmette-Guérin (BCG) infection remains incompletely defined. In this study, we investigated human CC- [macrophage-derived chemokine (MDC), monocyte chemoattractant protein (MCP)-1, macrophage inflammatory protein (MIP)-1alpha and eosinophil chemoattractant activity (eotaxin)] and CXC-interferon-inducible protein (IP)-10 chemokine production in response to BCG stimulation. BCG efficiently induced all chemokines tested in the urine of four bladder cancer patients undergoing intravesical BCG immunotherapy. The peak urinary chemokine responses occurred generally between the fourth and sixth weekly treatment, except eotaxin, which was less predictable. To evaluate the effect of BCG on induction of chemokines in vitro, urothelial cell lines and peripheral blood mononuclear cells (PBMCs) were used. Although BCG induced no or marginal chemokines from urothelial SV-HUC-1, RT4 and T24 cells, BCG-derived cytokines [interleukin (IL)-1beta, interferon (IFN)-gamma and tumour necrosis factor (TNF)-alpha] induced all chemokines tested except eotaxin from these cell lines. BCG also efficiently induced all chemokines tested except eotaxin from PBMCs of both BCG-naive and BCG-vaccinated subjects. MCP-1 and MIP-1alpha emerged at 4-5 h post-BCG exposure (early chemokines); IP-10 elevated at day 1 and peaked at day 2 (intermediate chemokine); and MDC elevated at day 1 and peaked at day 7 (late chemokine). This kinetic pattern was paralleled with that of BCG-induced cytokines [early: TNF-alpha; intermediate: IL-6 and IL-10; and late: IFN-gamma and granulocyte-macrophage colony-stimulating factor (GM-CSF)]. Taken together, these results indicate that BCG directly or indirectly induces human CC- and CXC-chemokine production, which may represent one of the mechanisms by which BCG exerts its anti-tumour activity.

Chemokines in renal diseases

The chemokines, members of a large family of chemotactic cytokines, act as directional cues for sorting inflammatory cell subsets to sites of inflammation or lymphoid microenvironments. In addition to their effects on migration, chemokines can also activate effector function in leukocytes and are involved in cell proliferation and angiogenesis. Therefore, it is not surprising that chemokines play important roles in a wide range of human diseases, including genetic immunodeficiencies, infections, autoimmune diseases, and malignant tumors. In this report, we have reviewed recent developments (since mid 2003) in chemokines in renal diseases. In animal models, chemokines are produced at the site of injury, leading to inflammatory cell recruitment. The therapeutic impact of the blockade of CCR1, CCR2, CCR4, CCR5, or the corresponding ligands has been further studied in various renal disease models. Recent studies on the role of the chemokine receptors in human diseases have demonstrated the expression of CXCR1, CXCR3, CCR2, and CCR5 on different subsets of inflammatory cells. The number of CCR5- and CXCR3-positive interstitial infiltrating cells (mainly T cells) correlates with renal function and proteinuria in glomerular diseases. Polymorphisms of chemokines and chemokine receptors are of impact on renal disease courses and allograft survival. Chemokine receptor blockade has approached clinical applications in nonrenal diseases and awaits the application in patients with kidney diseases.

Intrinsic expression of Th2 cytokines in urothelium of congenital ureteropelvic junction obstruction

BACKGROUND

The cytokine-producing ability of urothelium, a urinary tract barrier between urine and underlying connective tissue, may exacerbate the pathogenesis of congenital ureteropelvic junction obstruction (UPJ-O) disease. A role for urothelium in human urinary tract obstruction has rarely been described. In this study, we investigated the immunopathologic characteristics of, and cytokine production by, urothelium in children with congenital UPJ-O.

METHODS

Twenty-four children with congenital UPJ-O who had received pyeloplasty were enrolled. Morphologic abnormalities and pathologic and inflammatory changes of UPJ-O segments were studied. Expression of cytokines and chemokines in urothelium was investigated and compared with control tissue by immunohistochemistry (IHC), in situ hybridization (ISH), and urinary enzyme-linked immunosorbent assay (ELISA).

RESULTS

Atypical or simple hyperplasia of the urothelium with evidence of Ki67 over-expression was found frequently in UPJ-O. There were variable degrees of inflammatory cell and eosinophil infiltration. Augmented expression of IL-5 and eotaxin detected by IHC and ISH, and enhanced degranulation of tissue mast cells were observed in the urothelium of UPJ-O segments. IL-4, IFN-gamma, and TNF-alpha were undetectable. Significantly higher levels of urinary IL-5, IFN-gamma, and eotaxin were detected in urine collected from the obstructed kidney. Among these, high urinary IL5 and/or IFN-gamma levels were associated with more severe obstructive uropathy (P < 0.05).

CONCLUSION

Urothelium, like intestinal and respiratory epithelia, plays an active role in immunoregulation and may contribute to exacerbation of the pathogenesis of congenital UPJ-O. Many eosinophil-associated disease cytokines, which can lead to the degranulation of mast cells, are predominant regulators in UPJ-O urothelium.

Macrophage inflammatory protein-2, neutrophil recruitment and bacterial persistence in an experimental mouse model of urinary tract infection

This study analyzed macrophage inflammatory protein-2 (MIP-2) production and neutrophil recruitment in urinary tract in response to Pseudomonas aeruginosa in an ascending model of urinary tract infection (UTI) in mice. Both planktonic and biofilm cells of P. aeruginosa were used for inducing UTI in mice. MIP-2 levels determined in urine, bladder and kidney showed maximum MIP-2 production 6 h postinfection, which correlated with neutrophil recruitment. Biofilm cells showed significantly more MIP-2 production and neutrophil recruitment. However, no correlation between bacterial numbers and neutrophil recruitment was observed in urine and kidney tissue. The role of MIP-2 and neutrophils in relation to the persistence of P. aeruginosa in the urinary tract of mice is discussed.

Urine chemokines as biomarkers of human systemic lupus erythematosus activity

The purpose of this study was to evaluate urine monocyte chemoattractant protein-1 (MCP-1) and IL-8 as biomarkers of SLE flare. Urine was collected every 2 mo from patients who were followed prospectively in the Ohio SLE Study. Renal and nonrenal flares were identified and MCP-1 and IL-8 were measured by specific ELISA in samples that were collected at flare. When available, MCP-1 and IL-8 were also measured in urine samples before and after flare. For comparison, MCP-1 and IL-8 were measured in the urine of healthy individuals and in renal and nonrenal SLE patients with stable disease activity (disease controls). Most patients were receiving maintenance immunosuppressive therapy before flare. At renal flare, mean urine MCP-1 (uMCP-1) was significantly greater than uMCP-1 at nonrenal flare and from healthy volunteers and renal disease controls. The level of uMCP-1 correlated with the increase in proteinuria at flare and was higher in patients with proliferative glomerulonephritis and in patients with impaired renal function. Urine MCP-1 was increased beginning 2 to 4 mo before flare. Patients who responded to therapy showed a slow decline in uMCP-1 over several months, whereas nonresponders had persistently high uMCP-1. In contrast, uIL-8 did not change with disease activity and was not elevated at renal or nonrenal flare compared with disease controls. In conclusion, uMCP-1 but not uIL-8 is a sensitive and specific biomarker of renal SLE flare and its severity, even in patients who receive significant immunosuppressive therapy. Persistently elevated uMCP-1 after treatment may indicate ongoing kidney injury that may adversely affect renal prognosis.

CXCR3 and CCR5 positive T-cell recruitment in acute human renal allograft rejection

BACKGROUND

Experimental studies suggest that the infiltration of activated T cells into the allograft, the key event in the development of acute renal allograft rejection, depends on the expression of chemokines and their interaction with chemokine receptors expressed on T cells.

METHODS

For a more detailed comprehension of the pathogenesis of T-cell recruitment in human acute rejection, the in situ expression of chemokines and chemokine receptors in allografts of 26 patients between day 3 and 9 after renal transplantation was examined in the present prospective study.

RESULTS

Immunohistochemical staining showed a significantly increased number of CXCR3 (P<0.01) and CCR5 positive T cells (P<0.01) in the tubulointerstitium of patients with acute allograft rejection according to Banff grade Ia-IIb. Likewise the intrarenal RNA expression of the CXCR3 ligands IP-10 (5.2-fold) and I-TAC (7.2-fold) and the CCR5 ligand RANTES (5.7-fold), was significantly up-regulated in rejecting organs. In situ hybridization revealed that IP-10 but not I-TAC was predominantly expressed by infiltrating leukocytes in the tubulointerstitial area, co-localizing with CXCR3 positive T cells. To a lesser degree expression by tubular cells could be detected, providing a possible explanation for the increased urinary IP-10 excretion we found in patients with rejecting organs.

CONCLUSIONS

These data from a prospective, biopsy-controlled study indicate that the local expression of IP-10 and RANTES leads to the directional movement of activated CXCR3 and CCR5 bearing T cells into the renal allograft and mediates acute rejection. Our data provide a rationale that blocking CXCR3 and CCR5 may offer a unique therapeutic approach to prevent episodes of acute rejection in the early phase after renal transplantation.

Elevation of CXCR3-binding chemokines in urine indicates acute renal-allograft dysfunction

A noninvasive urinary test that diagnoses acute renal allograft dysfunction would benefit renal transplant patients. We aimed to develop a rapid urinary diagnostic test by detecting chemokines. Seventy-three patients with renal allograft dysfunction prompting biopsy and 26 patients with stable graft function were recruited. Urinary levels of CXCR3-binding chemokines, monokine induced by IFN-gamma (Mig/CXCL9), IFN-gamma-induced protein of 10 kDa (IP-10/CXCL10), and IFN-inducible T-cell chemoattractant (I-TAC/CXCL11), were determined by a particle-based triplex assay. IP-10, Mig and I-TAC were significantly elevated in renal graft recipients with acute rejection, acute tubular injury and BK virus nephritis. Using 100 pg/mL as the threshold level, both IP-10 and Mig had diagnostic value (sensitivity 86.4%; specificity 91.3%) in differentiating acute graft dysfunction from other clinical conditions. In terms of monitoring the response to antirejection therapy, this urinary test is more sensitive and predictive than serum creatinine. These results indicate that this rapid test is clinically useful.

Cytokines and chemokines in serum and urine as early predictors to identify septic patients on intensive care unit

The aim of this prospective cohort study was to address the feasibility of measuring cytokines in serum and urine as early predictor tests for the identification of septic Intensive Care Unit (ICU) patients. The study group consisted of 10 septic and 5 non-septic patients at the onset of sepsis according to modified definitions by the American College of Chest Physicians (ACCP)/Society of Critical Care Medicine (SCCM). Serum and urine samples were taken from septic patients at the onset of sepsis and from non-septic patients, every 12 h for 3 days and thereafter every 24 h until day 10. Levels of TNF-alpha, IL-1beta, IL-6, IL-10, IL-18, IFN-gamma, MCP-1, and PCT (procalcitonin) were measured by ELISA. Apart from serum IL-18 and PCT levels, which were elevated in septic patients (p<0.05), levels of all other cytokines and chemokines in the serum of septic patients did not exceed those of the control group. In urine, in contrast with TNF-alpha, IL-1beta, IL-6, IL-10, IFN-gamma, and MCP-1 in which no differences between the two groups were observed, a distinct trend of elevated IL-18 levels was observed only in the septic group. Whereas elevated serum IL-18 and PCT are clear candidate markers for sepsis criteria, the present data indicating elevated urine IL-18 levels albeit from a limited number of septic patients is an interesting observation. The profile of inflammatory mediators in serum and urine from septic patients herein warrants further investigations in a larger group of patients at the onset of sepsis driven by different infectious foci.