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BACKGROUND Rejection is the main cause of kidney allograft failure, and kidney biopsy is the criterion standard method to diagnose it. However, non-invasive techniques to detect kidney transplant rejection are necessary. This study aimed to evaluate urinary chemokines CXCL9 and CXCL10 as potential biomarkers of kidney transplant rejection and to analyze chemokine association with allograft prognosis. MATERIAL AND METHODS We collected 117 urine samples from kidney transplant recipients undergoing allograft biopsy. CXCL9 and CXCL10 levels were measured by ELISA and the ratio to urine creatinine was calculated. Histology and other clinical data were collected from medical records. RESULTS The diagnostic performance of urinary CXCL9/cre in discriminating rejection from all other histological groups showed an ROC AUC value of 0.728 (95% CI 0.632-0.824, p<0.001), and a cut-off value 0.11 ng/mmol had the best sensitivity (76.9%) and specificity (73.1%). The ability of CXCL10/cre to discriminate transplant rejection from all other histological groups had ROC AUC value 0.73 (95% CI 0.63-0.84, P<0.001), the cut-off value 0.42 ng/mmol with best sensitivity (71.4%) and specificity (84.6%). CXCL9 and CXCL10 levels were also increased in patients with polyoma BK virus, recurrent AA amyloidosis, and thrombotic microangiopathy. Patients with higher CXCL9/cre (≥0.11 ng/mmol) and CXCL10/cre (≥0.42 ng/mmol) levels were at increased risk of transplant progression to ESRD (HR 3.25, 95% CI=1.27-8.36, P=0.01), irrespective of serum creatinine at the time of biopsy. CONCLUSIONS Urinary CXCL9/cre and CXCL10/cre were able to distinguished between patients with transplant rejection and those without rejection. High levels of urinary CXCL9/cre and CXCL10/cre were associated with worse allograft survival.

In kidney transplant recipients, urine CXCL9 and CXCL10 (uCXCL9/10) chemokines have reached a sufficiently high level of evidence to be recommended by the European Society of Organ Transplantation for the monitoring of immune quiescence. To assess the risk of acute rejection (AR), the advantage of uCXCL9/10 is their cost-effectiveness and their high diagnostic performance. Here, we evaluated the feasibility of a next-generation immunoassay for quantifying uCXCL9/10 levels. It demonstrated high efficiency with minimal workflow and a 90-min time to result. Preanalytical studies indicated stability of uCXCL9/10 levels and analytical studies confirmed excellent linearity and precision. In a cohort of 1048 samples collected at biopsy, the results correlated significantly with ELISA quantification and were integrated into a previously validated 8-parameter urine chemokine model. The next generation immunoassay achieved an accuracy of 0.84 for AR diagnosis. This study validates this technology as a robust, locally available and unexpensive platform and marks a significant step towards the widespread implementation of uCXCL9/10, for immune quiescence monitoring. Therefore, we developed an open-access web application using uCXCL9/10 to calculate AR risk and improve clinical decision-making to perform biopsy, ushering in a new era in kidney transplantation, where personalized, data-driven care becomes the norm., (© 2024. The Author(s).)

CRISPR-based detection of target DNA or RNA exploits a dual function, including target sequence-specific recognition followed by trans -cleavage activity of a collateral ssDNA linker between a fluorophore (F) and a quencher (Q), which amplifies a fluorescent signal upon cleavage. In this work, we have extended such dual functionality in a modified immunoassay format to detect a target protein, CXCL9, which is markedly elevated in the urine of kidney transplant recipients undergoing acute rejection episodes. To establish the "immuno-CRISPR" assay, we used anti-CXCL9 antibody-DNA barcode conjugates to target CXCL9 and amplify fluorescent signals via Cas12a-based trans -cleavage activity of FQ reporter substrates, respectively, and in the absence of an isothermal amplification step. To enhance detection sensitivity, the DNA barcode system was engineered by introducing multiple Cas12a recognition sites. Use of biotinylated DNA barcodes enabled self-assembly onto streptavidin (SA) to generate SA-DNA barcode complexes to increase the number and density of Cas12a recognition sites attached to biotinylated anti-CXCL9 antibody. As a result, we improved the rate of CXCL9 detection approximately 8-fold when compared to the use of a monomeric DNA barcode. The limit of detection (LOD) for CXCL9 using the immuno-CRISPR assay was 14 pg/mL, which represented an ∼7-fold improvement when compared to traditional HRP-based ELISA. Selectivity was shown with a lack of crossover reactivity with the related chemokine CXCL1. Finally, we successfully evaluated the presence of CXCL9 in urine samples from 11 kidney transplant recipients using the immuno-CRISPR assay, resulting in 100% accuracy to clinical CXCL9 determination and paving the way for use as a point-of-care noninvasive biomarker for the detection of kidney transplant rejection.

Acute kidney injury (AKI) is nearly universally associated with worse outcomes, especially among children after hematopoietic stem cell transplant (HCT). Our objective was to examine urinary immune biomarkers of AKI after HCT to provide insights into novel mechanisms of kidney injury in this population. Studying patients undergoing allogeneic HCT provides a unique opportunity to examine immune markers of AKI because the risk of AKI is high and the immune system newly develops after transplant. Children (>2 years old) and young adults undergoing their first allogeneic HCT and enrolled in a prospective, observational cohort study at 2 large children's hospitals had urine collected pre-HCT and monthly for the first 4 months after HCT. Urine samples at each monthly time point were assayed for 8 immune-related biomarkers. AKI was defined as a 1.5-fold increase in the monthly serum creatinine value, which was recorded ±1 day from when the research urine sample was obtained, as compared with the pre-HCT baseline. Generalized estimating equation regression analysis evaluated the association between the monthly repeated measures (urinary biomarkers and AKI). A total of 176 patients were included from 2 pediatric centers. Thirty-six patients from 1 center were analyzed as a discovery cohort and the remaining 140 patients from the second center were analyzed as a validation cohort. AKI rates were 18% to 35% depending on the monthly time point after HCT. Urine CXCL10 and CXCL9 concentrations were significantly higher among children who developed AKI compared with children who did not (P < .01) in both cohorts. In order to gain a better understanding of the cellular source for these biomarkers in the urine, we also analyzed in vitro expression of CXCL10 and CXCL9 in kidney cell lines after stimulation with interferon-γ and interferon-α. HEK293-epithelial kidney cells demonstrated interferon-induced expression of CXCL10 and CXCL9, suggesting a potential mechanism driving the key finding. CXCL10 and CXCL9 are associated with AKI after HCT and are therefore promising biomarkers to guide improved diagnostic and treatment strategies for AKI in this high-risk population., (Copyright © 2020 American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc. All rights reserved.)

In organ transplantation, infection and rejection are major causes of graft loss. They are linked by the net state of immunosuppression. To diagnose and treat these conditions earlier, and to improve long-term patient outcomes, refined strategies for the monitoring of patients after graft transplantation are needed. Here, we show that a fast and inexpensive assay based on CRISPR-Cas13 accurately detects BK polyomavirus DNA and cytomegalovirus DNA from patient-derived blood and urine samples, as well as CXCL9 messenger RNA (a marker of graft rejection) at elevated levels in urine samples from patients experiencing acute kidney transplant rejection. The assay, which we adapted for lateral-flow readout, enables-via simple visualization-the post-transplantation monitoring of common opportunistic viral infections and of graft rejection, and should facilitate point-of-care post-transplantation monitoring.

Conversion to belatacept immunosuppression is a therapeutic option for renal-transplant recipients with calcineurin inhibitors (CNI) toxicity, but it associates with high risk of acute rejection. Gradual conversion and serial immune monitoring with urinary chemokine CXCL9 may allow increasing safety of this maneuver. We converted kidney transplant recipients with signs of toxicity to CNI or other immunosuppressive drugs to belatacept over a 2-month period. We monitored renal function, metabolic profile, and circulating lymphocyte subsets. We also quantified urinary CXCL9 over a 12-month follow-up period. Between September 2016 and March 2017, 35 patients were successfully switched to belatacept immunosuppression at 3.3 (1.3-7.2) years after transplant. Two patients had a reversible rise in serum creatinine, associated with acute rejection in one case. Urinary CXCL9 increased before serum creatinine. After conversion, blood pressure and HbA1c significantly declined while eGFR and proteinuria remained stable. The percentage of circulating effector T cells and memory B cells significantly declined. Conversion from CNI to belatacept, in this setting, was feasible and safe, provided it was performed over a 2-month time-period. Monitoring urinary CXCL9 may further increase safety through earlier identification of patients at risk for acute rejection. The procedure associates with improved blood pressure, metabolic profile, and reduced circulating effector T and B cells., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Background: An early posttransplant biomarker/surrogate marker for kidney allograft loss has the potential to guide targeted interventions. Previously published findings, including results from the Clinical Trials in Organ Transplantation (CTOT)-01 study, showed that elevated urinary chemokine CXCL9 levels and elevated frequencies of donor-reactive interferon gamma (IFNγ)-producing T cells by enzyme-linked immunosorbent spot (ELISPOT) assay associated with acute cellular rejection within the first year and with lower 1-year posttransplant estimated glomerular filtration rate (eGFR). How well these biomarkers correlate with late outcomes, including graft loss, is unclear., Methods: In CTOT-17, we obtained 5-year outcomes in the CTOT-01 cohort and correlated them with (a) biomarker results and (b) changes in eGFR (Chronic Kidney Disease Epidemiology Collaboration formula) over the initial 2 years posttransplant using univariable analysis and multivariable logistic regression., Results: Graft loss occurred in 14 (7.6%) of 184 subjects 2 to 5 years posttransplant. Neither IFNγ ELISPOTs nor urinary CXCL9 were informative. In contrast, a 40% or greater decline in eGFR from 6 months to 2 years posttransplant independently correlated with 13-fold odds of 5-year graft loss (adjusted odds ratio, 13.1; 95% confidence interval, 3.0-56.6), a result that was validated in the independent Genomics of Chronic Allograft Rejection cohort (n = 165; adjusted odds ratio, 11.2)., Conclusions: We conclude that although pretransplant and early posttransplant ELISPOT and chemokine measurements associate with outcomes within 2 years posttransplant, changes in eGFR between 3 or 6 months and 24 months are better surrogates for 5-year outcomes, including graft loss.

Purpose of Review: Improved long-term kidney allograft survival remains a critical goal in transplantation; the achievement of this, however, is highly dependent on the identification of biomarkers that can either predict or allow advance detection of patients at risk of allograft injury. The present review outlines the commonly used biomarkers in kidney transplantation, while also highlighting those currently under investigation, discussing their advantages and limitations., Recent Findings: Most of the approved biomarkers currently used in kidney transplantation capture antigen recognition or alloantibody production. However, tremendous progress has recently been made in the development of markers of other signaling pathways pertinent to the alloimmune response. Microarray gene sets that predict rejection or poor prognostic phenotypes have been identified in kidney biopsies (the 'molecular microscope diagnostic system' and the 'genomics of chronic allograft rejection' scores), peripheral blood (the 'kidney solid organ response test'), and urine (the '3-genes signature'). Strategies targeting serial measurements of urinary chemokines such as CXCL9 and CXCL10 also appear promising., Summary: Although the range of biomarkers in current use is limited, there are many assays in the development and validation pipeline that appear promising but that have yet to reach mainstream clinical transplantation. The 'ideal biomarker' may eventually transpire to be the combination of several assays.

Diabetic nephropathy (DN) is a serious and one of the most common microvascular complications of diabetes. There is accumulating evidence to indicate that advanced glycation end products (AGEs), senescent macroprotein derivatives formed at an accelerated rate under conditions of diabetes, play a role in DN. In this study, we found that the serum and urine levels of C-X-C motif chemokine ligand 9 (CXCL9) were significantly elevated in patients with DN compared with healthy controls. Based on an in vitro model of mouse podocyte injury, AGEs decreased the proliferation of podocytes and increased the expression of CXCL9 and C-X-C motif chemokine receptor 3 (CXCR3), and promoted the activation of signal transducer and activator of transcription 3 (STAT3). The knockdown of CXCL9 by the transfection of mouse podoyctes with specific siRNA significantly increased the proliferation and decreased the apoptosis of the podoyctes. Moreover, the levels of inflammatory factors, such as tumor necrosis factor (TNF)‑α and interleukin (IL)‑6 were also decreased in the podoyctes transfected with siRNA-CXCL9, accompanied by the increased expression of nephrin and podocin, and decreased levels of Bax/Bcl-2 and activated caspase-3. The knockdown of CXCL9 also led to the inactivation of the Janus kinase 2 (JAK2)/STAT3 pathway. Importantly, the use of the JAK2 inhibitor, AG490, and valsartan (angiotensin II receptor antagonist) attenuated the injury induced to mouse podoyctes by AGEs. On the whole, and to the best of our knowledge, this study demonstrates for the first time that AGEs exert pro-apoptotic and pro-inflammatory effects in mouse podoyctes through the CXCL9-mediated activation of the JAK2/STAT3 pathway. Thus, our data provide a potential therapeutic target for DN.

We monitored the urinary C-X-C motif chemokine (CXCL)9 and CXCL10 levels in 1722 urine samples from 300 consecutive kidney recipients collected during the first posttransplantation year and assessed their predictive value for subsequent acute rejection (AR). The trajectories of urinary CXCL10 showed an early increase at 1 month (p = 0.0005) and 3 months (p = 0.0009) in patients who subsequently developed AR. At 1 year, the AR-free allograft survival rates were 90% and 54% in patients with CXCL10:creatinine (CXCL10:Cr) levels <2.79 ng/mmoL and >2.79 ng/mmoL at 1 month, respectively (p < 0.0001), and 88% and 56% in patients with CXCL10:Cr levels <5.32 ng/mmoL and >5.32 ng/mmoL at 3 months (p < 0.0001), respectively. CXCL9:Cr levels also associate, albeit less robustly, with AR-free allograft survival. Early CXCL10:Cr levels predicted clinical and subclinical rejection and both T cell- and antibody-mediated rejection. In 222 stable patients, CXCL10:Cr at 3 months predicted AR independent of concomitant protocol biopsy results (p = 0.009). Although its positive predictive value was low, a high negative predictive value suggests that early CXCL10:Cr might predict immunological quiescence on a triple-drug calcineurin inhibitor-based immunosuppressive regimen in the first posttransplantation year, even in clinically and histologically stable patients. The clinical utility of this test will need to be addressed by dedicated prospective clinical trials., (© Copyright 2015 The American Society of Transplantation and the American Society of Transplant Surgeons.)

Concerns about adverse effects of calcineurin inhibitors (CNIs) have prompted development of protocols that minimize their use. Whereas previous CNI withdrawal trials in heterogeneous cohorts showed unacceptable rates of acute rejection (AR), we hypothesized that we could identify individuals capable of tolerating CNI withdrawal by targeting immunologically quiescent kidney transplant recipients. The Clinical Trials in Organ Transplantation-09 Trial was a randomized, prospective study of nonsensitized primary recipients of living donor kidney transplants. Subjects received rabbit antithymocyte globulin, tacrolimus, mycophenolate mofetil, and prednisone. Six months post-transplantation, subjects without de novo donor-specific antibodies (DSAs), AR, or inflammation at protocol biopsy were randomized to wean off or remain on tacrolimus. The intended primary end point was the change in interstitial fibrosis/tubular atrophy score between implantation and 24-month protocol biopsies. Serially collected urine CXCL9 ELISA results were correlated with outcomes. The study was terminated prematurely because of unacceptable rates of AR (4 of 14) and/or de novo DSAs (5 of 14) in the tacrolimus withdrawal arm. Positive urinary CXCL9 predated clinical detection of AR by a median of 15 days. Analyses showed that >16 HLA-DQ epitope mismatches and pretransplant, peripheral blood, donor-reactive IFN-γ ELISPOT assay results correlated with development of DSAs and/or AR on tacrolimus withdrawal. Although data indicate that urinary CXCL9 monitoring, epitope mismatches, and ELISPOT assays are potentially informative, complete CNI withdrawal must be strongly discouraged in kidney transplant recipients who are receiving standard-of-care immunosuppression, including those who are deemed to be immunologically quiescent on the basis of current clinical and laboratory criteria., (Copyright © 2015 by the American Society of Nephrology.)

Urinary levels of C-X-C motif chemokine 9 (CXCL9) and CXCL10 can noninvasively diagnose T cell-mediated rejection (TCMR) of renal allografts. However, performance of these molecules as diagnostic/prognostic markers of antibody-mediated rejection (ABMR) is unknown. We investigated urinary CXCL9 and CXCL10 levels in a highly sensitized cohort of 244 renal allograft recipients (67 with preformed donor-specific antibodies [DSAs]) with 281 indication biopsy samples. We assessed the benefit of adding these biomarkers to conventional models for diagnosing/prognosing ABMR. Urinary CXCL9 and CXCL10 levels, normalized to urine creatinine (Cr) levels (CXCL9:Cr and CXCL10:Cr) or not, correlated with the extent of tubulointerstitial (i+t score; all P<0.001) and microvascular (g+ptc score; all P<0.001) inflammation. CXCL10:Cr diagnosed TCMR (area under the curve [AUC]=0.80; 95% confidence interval [95% CI], 0.68 to 0.92; P<0.001) and ABMR (AUC=0.76; 95% CI, 0.69 to 0.82; P<0.001) with high accuracy, even in the absence of tubulointerstitial inflammation (AUC=0.70; 95% CI, 0.61 to 0.79; P<0.001). Although mean fluorescence intensity of the immunodominant DSA diagnosed ABMR (AUC=0.75; 95% CI, 0.68 to 0.82; P<0.001), combining urinary CXCL10:Cr with immunodominant DSA levels improved the diagnosis of ABMR (AUC=0.83; 95% CI, 0.77 to 0.89; P<0.001). At the time of ABMR, urinary CXCL10:Cr ratio was independently associated with an increased risk of graft loss. In conclusion, urinary CXCL10:Cr ratio associates with tubulointerstitial and microvascular inflammation of the renal allograft. Combining the urinary CXCL10:Cr ratio with DSA monitoring significantly improves the noninvasive diagnosis of ABMR and the stratification of patients at high risk for graft loss., (Copyright © 2015 by the American Society of Nephrology.)

Objective: Increasing evidence suggests that T helper (Th) cells play a significant role in the pathogenesis of hypertension. The aim of this study was to evaluate the effect of obesity and anti-hypertensive treatment on urinary Th1 chemokines., Methods: The study groups consisted of three types of patients: hypertensive obese, healthy, and non-hypertensive obese. Pre-treatment and post-treatment samples of the hypertensive obese group and one sample from the other two groups were evaluated for urinary chemokine: regulated on activation, normal T cell expressed and secreted (RANTES), interferon-gamma-inducible protein 10 (IP10), and monokine induced by interferon-gamma (MIG). In the hypertensive obese group, urine microalbumin: creatinine ratio was examined before and after treatment. We recommended lifestyle changes to all patients. Captopril was started in those who could not be controlled with lifestyle changes and those who had stage 2 hypertension., Results: Twenty-four hypertensive obese (mean age 13.1), 27 healthy (mean age 11.2) and 22 non-hypertensive obese (mean age 11.5) children were investigated. The pre-treatment urine albumin: creatinine ratio was positively correlated with pre-treatment MIG levels (r=0.41, p<0.05). RANTES was significantly higher in the pre-treatment hypertensive and non-hypertensive obese group than in the controls. The urinary IP10 and MIG levels were higher in the pre-treatment hypertensive obese group than in the non-hypertensive obese. Comparison of the pre- and post-treatment values indicated significant decreases in RANTES, IP10, and MIG levels in the hypertensive obese group (p<0.05)., Conclusion: Th1 cells could be activated in obese hypertensive children before the onset of clinical indicators of target organ damage. Urinary RANTES seemed to be affected by both hypertension and obesity, and urinary IP10 and MIG seemed to be affected predominantly by hypertension.

Noninvasive biomarkers are needed to assess immune risk and ultimately guide therapeutic decision-making following kidney transplantation. A requisite step toward these goals is validation of markers that diagnose and/or predict relevant transplant endpoints. The Clinical Trials in Organ Transplantation-01 protocol is a multicenter observational study of biomarkers in 280 adult and pediatric first kidney transplant recipients. We compared and validated urinary mRNAs and proteins as biomarkers to diagnose biopsy-proven acute rejection (AR) and stratify patients into groups based on risk for developing AR or progressive renal dysfunction. Among markers tested for diagnosing AR, urinary CXCL9 mRNA (odds ratio [OR] 2.77, positive predictive value [PPV] 61.5%, negative predictive value [NPV] 83%) and CXCL9 protein (OR 3.40, PPV 67.6%, NPV 92%) were the most robust. Low urinary CXCL9 protein in 6-month posttransplant urines obtained from stable allograft recipients classified individuals least likely to develop future AR or a decrement in estimated glomerular filtration rate between 6 and 24 months (92.5-99.3% NPV). Our results support using urinary CXCL9 for clinical decision-making following kidney transplantation. In the context of acute dysfunction, low values can rule out infectious/immunological causes of injury. Absent urinary CXCL9 at 6 months posttransplant defines a subgroup at low risk for incipient immune injury., (© Copyright 2013 The American Society of Transplantation and the American Society of Transplant Surgeons.)

Renal transplant recipients require periodic surveillance for immune-based complications such as rejection and infection. Noninvasive monitoring methods are preferred, particularly for children, for whom invasive testing is problematic. We performed a cross-sectional analysis of adult and pediatric transplant recipients to determine whether a urine-based chemokine assay could noninvasively identify patients with rejection among other common clinical diagnoses. Urine was collected from 110 adults and 46 children with defined clinical conditions: healthy volunteers, stable renal transplant recipients, and recipients with clinical or subclinical acute rejection (AR) or BK infection (BKI), calcineurin inhibitor (CNI) toxicity or interstitial fibrosis (IFTA). Urine was analyzed using a solid-phase bead-array assay for the interferon gamma-induced chemokines CXCL9 and CXCL10. We found that urine CXCL9 and CXCL10 were markedly elevated in adults and children experiencing either AR or BKI (p = 0.0002), but not in stable allograft recipients or recipients with CNI toxicity or IFTA. The sensitivity and specificity of these chemokine assays exceeded that of serum creatinine. Neither chemokine distinguished between AR and BKI. These data show that urine chemokine monitoring identifies patients with renal allograft inflammation. This assay may be useful for noninvasively distinguishing those allograft recipients requiring more intensive surveillance from those with benign clinical courses., (©Copyright 2011 The American Society of Transplantation and the American Society of Transplant Surgeons.)

Background: Chronic renal allograft injury resulting in progressive interstitial fibrosis and tubular atrophy (IFTA) is a leading cause of graft loss. The goal of this study was to identify early urinary predictors for the subsequent development of IFTA in a prospective cohort of patients (n=111) who underwent serial protocol biopsies at 0, 6, and 24 months., Methods: The urinary proteins evaluated were CCL2, CXCL9, CXCL10, and alpha1-microglobulin (alpha1M) using ELISA and immunonephelometry., Results: We first evaluated urines obtained at 1 to 3 months and found that alpha1M and CXCL10 were associated with IFTA at 6 months but not at 24 months. Next, we evaluated urines at 6 months and found that CCL2 was associated with both IFTA and graft dysfunction at 24 months. On univariate analysis, 6-month urinary CCL2 was a risk factor for developing 24-month IFTA, defined as ci+ct score more than 0 (odds ratio 1.045, 95% confidence interval: 1.005-1.084, P=0.028). Furthermore, CCL2 remained an independent predictor of IFTA on multivariate analysis (odds ratio 1.049, 95% confidence interval: 1.006-1.094, P=0.024) when adjusted for donor age, delayed graft function, deceased donation, and angiotensin-converting enzyme inhibitor/angiotensin receptor blocker exposure. In comparison, alpha1M, CXCL9, and CXCL10 were not associated with late graft outcomes., Conclusion: This study demonstrates that early urinary CCL2 is an independent predictor for the subsequent development of IFTA at 24 months.

Subclinical tubulitis has been associated with the later development of interstitial fibrosis and tubular atrophy (IF/TA), leading to diminished allograft survival. The aim of this study was to investigate how concentrations of urinary CXC-receptor 3 (CXCR3) chemokines (i.e. CXCL4/9/10/11) and CCL2 relate to the extent of subclinical tubulitis. Using ELISA, urinary CXCR3 chemokines, CCL2 and tubular injury markers (i.e. urinary NGAL and alpha1-microglobulin [alpha1 m]) were measured in patients with stable estimated GFR >or=40 mL/min exhibiting normal tubular histology (n = 24), subclinical borderline tubulitis (n = 18) or subclinical tubulitis Ia/Ib (n = 22), as well as in patients with clinical tubulitis Ia/Ib (n = 17) or IF/TA (n = 10). CXCL9 and CXCL10 were significantly higher in subclinical tubulitis Ia/Ib than in subclinical borderline tubulitis (p

CXC chemokines are particularly significant for leukocyte infiltration in inflammatory diseases. Recent reports have shown that inflammation is one of potential pathogenic mechanisms for diabetic nephropathy. However, information on inflammation related with CXC chemokines in human Type 2 diabetic nephropathy still remains scarce. We measured urinary and serum levels of three CXC chemokines, CXCL5, CXCL8 and CXCL9, in 45 Type 2 diabetic patients (DM), 42 primary renal disease (PRD) patients and 22 healthy controls by enzyme-linked immunosorbent assay. Urinary levels of CXCL5, CXCL8 and CXCL9 in DM were significantly elevated compared to those in controls (P<.0001, P<.01, P<.001; respectively). They increased consistent with urinary albumin excretion rate (UAER) and correlated with UAER in partial correlation analyses (r=0.41, P<.01; r=0.40, P<.01; r=0.45, P<.01; respectively). Urinary levels of CXCL5 in DM were significantly interrelated to HbA(1c) (r=0.42, P<.01). On the other hand, PRD showed significant increased levels of urinary CXCL8 and CXCL9 compared to controls (P<.001, P<.01; respectively), and so did PRD as UAER increased. However, there were no significant elevations of urinary levels of CXCL5 in PRD in spite of the increased UAER. We found significant associations of UAER in DM with diabetes duration, 1/serum creatinine, urinary CXCL5 (adjusted R(2)=0.67, P<.0001) or CXCL9 (adjusted R(2)=0.69, P<.0001) in a stepwise multiple regression analysis. These results suggest that these three CXC chemokines may be involved in the progression of human Type 2 diabetic nephropathy and that CXCL5 may be of use for telling diabetic nephropathy from primary renal diseases.