Renal fibrosis is the central pathogenic process in progression of chronic kidney disease (CKD). Collagen type VI (COL VI) is upregulated in renal fibrosis. Endotrophin is released from COL VI and ...promotes pleiotropic pro-fibrotic effects. Kidney disease severity varies considerably and accurate information regarding CKD progression may improve clinical decisions. We tested the hypothesis that urinary endotrophin derived during COL VI deposition in fibrotic human kidneys is a marker for progression of CKD in the Renal Impairment in Secondary Care (RIISC) cohort, a prospective observational study of 499 CKD patients. Endotrophin localised to areas of increased COL VI deposition in fibrotic kidneys but was not present in histologically normal kidneys. The third and fourth quartiles of urinary endotrophin:creatinine ratio (ECR) were independently associated with one-year disease progression after adjustment for traditional risk factors (OR (95%CI) 3.68 (1.06-12.83) and 8.65 (2.46-30.49), respectively). Addition of ECR quartiles to the model for disease progression increased prediction as seen by an increase in category-free net reclassification improvement (0.45, 95% CI 0.16-0.74, p = 0.002) and integrated discrimination improvement (0.04, 95% CI 0.02-0.06, p < 0.001). ECR was associated with development of end-stage renal disease (ESRD). It is concluded that ECR predicts disease progression of CKD patients.
Background: The drug combinations for rewriting trajectories of renal pathologies in type 2 diabetes (DC-ren) study focuses on DKD, a complication of diabetes often accompanied by cardiovascular ...disease. Novel biomarkers for identifying persons at increased risk of disease progression and predicting treatment response are currently needed. Levels of urinary C3M, a marker of type III collagen degradation, have been shown to correlate with CKD progression, and dulaglutide treatment improved levels of this biomarker compared with insulin glargine in persons with type 2 diabetes (T2D). We investigated the effect of combination therapy on urinary C3M in persons with T2D.
Method: We measured urinary C3M in urine collected at baseline and after years 1, 2, and 3 from 229 individuals with T2D enrolled in the DC-ren study. All persons were on renin-angiotensin system inhibitor (RASi) treatment at baseline and during follow-up. While some persons remained on RASi treatment (n = 184), others received glucagon-like peptide-1 receptor agonist (GLP-1 RA) on top of RASi (n = 45).
Results: The cohort consisted of 48% males (age of 66 ± 8 years and eGFR was 65 ± 17 ml/min/1.73 m2). Lower baseline levels of urinary C3M were associated with lower eGFR, and this relation remained consistent over time. Levels of urinary C3M were higher in persons after treatment with GLP-1 RA in combination with RASi compared to RASi alone (P = 0.034). In adjusted linear models (for the RASi group), an association of current urinary C3M with future eGFR was found (P < 0.01), indicating that urinary C3M is a prognostic risk marker for kidney function decline.
Conclusion: RASi in combination with GLP-1 RA treatment was associated with increased type III collagen degradation, suggesting a potential effect to reduce kidney fibrosis. This anti-fibrotic effect could be a mechanism for the beneficial effects observed with GLP-1 RA treatment on CKD in T2D.
Disclosure
A.Møller: None. S.Thöni: None. C.F.G.Laursen: None. M.A.Karsdal: Speaker's Bureau; Pfizer Inc. F.Genovese: Employee; Nordic Bioscience A/S, Stock/Shareholder; Nordic Bioscience A/S. D.Rasmussen: Employee; Nordic Bioscience A/S, Stock/Shareholder; Nordic Bioscience A/S.
Patients with chronic kidney disease (CKD) have increased risk of development of end-stage renal disease (ESRD) and early mortality. Fibrosis is the central pathogenic process in CKD and is caused by ...dysregulated extracellular matrix (ECM) remodeling. The laminin γ1 chain (LAMC1) is a core structural protein present in the basement membrane of several organs, including the kidneys. We hypothesized that dysregulation of LAMC1 remodeling could be associated with a higher risk of adverse clinical outcomes in patients with CKD.
A novel immunoassay targeting LG1M, a specific MMP-9-generated neo-epitope fragment of LAMC1, was developed and used to measure the levels of the fragment in urine and serum from 492 patients from the Renal Impairment in Secondary Care (RIISC) study, a prospective cohort of patients with high-risk CKD. Patients were monitored for a median follow-up time of 3.5 years. Associations between serum and urine LG1M levels and progression of CKD at 12 months were assessed by a multivariable logistic regression model. The association with ESRD or mortality was assessed by Kaplan-Meier survival curves and Cox proportional hazards regression.
Forty-six (11%) of the 416 patients who reached 12-month follow-up had progression of CKD; during the study follow-up, 125 patients (25.4%) developed ESRD and 71 patients (14.4%) died. Serum and urine levels of LG1M correlated with baseline eGFR (r = -0.43, p<0.0001 and r = -0.17, p = 0.0002, respectively). Serum levels of LG1M were higher in patients with one-year progression of CKD compared to those who did not progress (p<0.01). Baseline serum levels of LG1M were associated with development of ESRD (HR 3.2, 95% CI 1.99-5.2 for patients in the highest LG1M tertile compared to patient in the lowest tertile). Baseline urinary levels of LG1M (uLG1M) were significantly associated with mortality (HR 5.0, 95% CI 2.8-8.9, p<0.0001 for patients in the highest LG1M tertile compared to patients in the lowest tertile). Urine LG1M was retained in the model for prediction of mortality (HR per standard deviation of uLG1M: 1.01, 95% CI 1.00-1.02, p = 0.001).
LG1M, a marker of basement membrane remodeling, is increased in serum and urine of patients with CKD and levels are associated with one-year disease progression, development of ESRD, and mortality.
Background: Glucagon-like peptide 1 receptor agonists (GLP-1 RAs) and sodium-glucose co-transporter-2 inhibitors (SGLT2i) demonstrated cardiovascular (CV) and kidney outcomes benefit in persons with ...type 2 diabetes (T2D). The long-acting amylin analogue, cagrilintide, is under investigation for the treatment of obesity and T2D. Endotrophin, a pro-fibrotic fragment derived from collagen type VI, is an independent risk marker of mortality, CV and kidney outcomes, and dulaglutide treatment decreased levels of this biomarker compared with insulin glargine in persons with T2D. We investigated for the first time the effect of semaglutide, empagliflozin, and cagrilintide on endotrophin in type 2 diabetic rats.
Method: We measured endotrophin (by the rodent PRO-C6 ELISA) in serum collected at baseline and study end from diabetic ZDF rats treated with either vehicle (n = 10), semaglutide (n = 7), empagliflozin (n = 4), or cagrilintide (n = 10). The dose chosen for semaglutide (50 nmol/kg), empagliflozin (30 mg/kg), and cagrilintide (10 nmol/kg) was based on previous research.
Results: Levels of endotrophin increased significantly during the study in vehicle-treated rats, reflecting the disease progression (median 95% CI for increase: 182.5 55.87-298.0, P < 0.01). Interestingly, treatment with semaglutide, empagliflozin, and cagrilintide each attenuated this increase, resulting in significantly lower levels of endotrophin compared to vehicle at study end (P < 0.01), (P < 0.05), and (P < 0.01), respectively.
Conclusion: We developed a novel, robust assay to detect the clinically relevant endotrophin biomarker in rodents. Levels of serum endotrophin increased over time in vehicle-treated rats, which is in line with endotrophin predicting disease progression in persons with T2D. In addition to the beneficial effects on metabolic factors, semaglutide, empagliflozin, and cagrilintide each reduced levels of endotrophin, suggesting a potential effect to reduce fibrosis.
Disclosure
A.Møller: None. S.A.Melander: None. A.T.Larsen: Employee; Nordic Bioscience A/S. C.F.G.Laursen: None. F.Genovese: Employee; Nordic Bioscience A/S, Stock/Shareholder; Nordic Bioscience A/S. M.A.Karsdal: Speaker's Bureau; Pfizer Inc. D.Rasmussen: Employee; Nordic Bioscience A/S, Stock/Shareholder; Nordic Bioscience A/S. K.Henriksen: Employee; Nordic Bioscience A/S, Stock/Shareholder; Nordic Bioscience A/S.
Renal fibrosis is a hallmark of chronic kidney disease (CKD) caused by an imbalance between formation and degradation of extracellular matrix proteins. We investigated the collagen turnover profile ...of 81 non-dialysis CKD stage 2-5 patients by measuring peptides reflecting formation and degradation of collagen type (COL) I, III, IV, and VI. Based on the collagen turnover profile, we identified four clusters of patients. Cluster 1 contained one patient with prostate cancer, who had a distinct collagen turnover. The other clusters generally had severe (Cluster 2), moderate (Cluster 4), or mild CKD (Cluster 3). Cluster 4 patients were characterized by higher levels of COL III, COL IV, and COL VI (all p < 0.001) degradation fragments in plasma, while patients in Clusters 2 and 4 had higher levels of COL VI formation (p < 0.05). COL IV fragments in plasma were lower in Cluster 2 (p < 0.01). Urinary COL III fragments decreased from Cluster 3 to 4, and from Cluster 4 to 2 (both p < 0.001). We show that patients with similar kidney function have a different collagen remodeling profile, suggesting that different phenotypes exist with different disease activity and potentially disease progression. Biomarkers of collagen remodeling could provide additional information to traditional markers of renal function.
Peptide receptor radionuclide therapy (PRRT) is a treatment for neuroendocrine tumours (NET). Renal impairment is a known side effect due to kidney fibrosis. We investigated the association between ...novel specific fibrosis markers and kidney function following PRRT. We included 38 patients who had all finished PRRT. In serum and urine, we analysed levels of three different fibrosis markers, PRO-C6 (type VI collagen formation), PRO-C3 (type III collagen formation) and C3M (type III collagen degradation). We determined kidney function by the
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Cr-EDTA plasma clearance. We used Wilcoxon rank sum test and Spearman's rank correlation to evaluate the association between the fibrosis markers and kidney function. We included 38 NET patients, 25 small-intestinal NET, 6 pancreatic NET, 2 pulmonary NET and 5 other types of NET. Median age was 69 years (IQR: 61-73). Median time from last PRRT to inclusion was 8 months (IQR: 3-20). We found significantly increased levels of serum PRO-C6 (p = .007) and urinary PRO-C6 (p = .033) and significantly decreased levels of urinary C3M (p = .035) in patients with impaired kidney function. Further, we observed a negative association between serum PRO-C6 and kidney function (rho = −0.33, p = .04) and a positive association between urinary C3M and kidney function (rho = 0.37, p = .02). We showed an association between the three fibrosis markers, serum PRO-C6, urinary PRO-C6 and urinary C3M and kidney function. These markers may help to improve the understanding of potential pathological tissue turnover and potentially improve monitoring of kidney function after PRRT in NET patients.
Enhanced de-novo collagen type VI (COL VI) formation has been associated with kidney and cardiovascular fibrosis. We hypothesized that endotrophin (ETP), a product specifically generated during ...collagen type VI formation, may be prognostic for heart failure (HF), cardiovascular death (CVD), kidney endpoints, and all-cause mortality in patients with type 2 diabetes.
We measured ETP in plasma (P-ETP) and urine (U-ETP) samples collected at baseline and follow-up (year 3) from the randomized controlled trial, CANagliflozin cardioVascular Assessment Study (CANVAS), by use of the PRO-C6 ELISA measuring COL VI formation and ETP. At baseline, plasma and urine samples were available for 3531 and 3423 patients, respectively. At year 3, plasma and urine samples were available for 2178 (61.7%) and 2070 (60.5%) patients, respectively Patients were followed for a median of 6.1 years, and endpoints included: incident HF, CVD, three kidney composite endpoints, and all-cause mortality. Backward selection was used to identify variables to be included in the analyses. Robustness of the association with outcome was assessed by bootstrap analyses.
In univariable analysis, P-ETP predicted all investigated outcomes (all p < 0.0001), remained independently associated with all outcomes after adjustment for conventional risk factors (all p < 0.004), and increased C-statistics of the models for the outcomes HF, CVD, HFCVD, all-cause mortality, and kidney composite 2 (ΔC ≥ 0.002). In bootstrap analysis, P-ETP was retained with a frequency ranging from 41.0 to 98.4% for all outcomes. Levels of U-ETP were associated with outcomes in univariable analysis, but associations with most outcomes were lost after adjustment for conventional risk factors. The increase in P-ETP over time was greater with increasing albuminuria stage (p < 0.0001) and was independently associated with the kidney endpoints (p < 0.03). In the placebo arm, the increase in P-ETP was prognostic for all-cause mortality (HR 95% CI; 1.14 1.05-1.23, p = 0.003). Whereas levels of P-ETP were not impacted by treatment, levels of U-ETP significantly increased with canagliflozin treatment.
P-ETP generated during COL VI formation predicts cardiovascular, kidney and mortality outcomes in patients with type 2 diabetes. As ETP identifies patients at increased risk of experiencing relevant outcomes, it may be used for patient enrichment in future clinical trials. Trial Registry Number (ClinicalTrials.gov Identifier): NCT01032629.
Natural cytokine-specific autoantibodies (c-aAb) have been measured in healthy and diseased individuals, and have been considered as both endogenous immune-regulators and pathogenic factors. Overall, ...the etiology and potential pathology of c-aAb are still undefined. To further characterize the sero-prevalence, predictors and consequences of high c-aAb levels, we performed the largest population-based study of c-aAb to date, using participants and epidemiological data from the Danish Blood Donor Study. Using a validated bead-based multiplex assay we assessed plasma levels of IL-1α, IL-6, IL-10, IFNα and GM-CSF-specific c-aAb in 8,972 healthy blood donors. Trace levels of at least one of the investigated c-aAb could be measured in 86% of the participants. The presence of high levels of potentially inhibitory c-aAb was generally associated with increasing age and male or female sex, depending on the c-aAb in question. A negative correlation between high levels of IL-6-specific c-aAb and plasma levels of C-reactive protein was observed, indicating cytokine-neutralizing levels of c-aAb in healthy blood donors. There was no substantial correlation between high levels of the five individual c-aAb investigated in this study. These data suggest that autoimmunity against endogenous cytokines is a relatively common phenomenon in healthy individuals, and that predictive factors for high, potentially neutralizing c-aAb levels vary depending on the cytokine in question, and may differ from predictors of general c-aAb presence.
Renal fibrogenesis is associated with increased ECM remodeling and release of collagen fragments in urine in progressive renal disease. We investigated the diagnostic value of urinary collagen ...degradation products in a proteinuria-driven fibrosis rat model with and without anti-fibrotic S1P-receptor modulator FTY720 treatment.
Proteinuria was induced in male Wistar rats by Adriamycin (ADR) injection (n = 16). Healthy rats served as controls (n = 12). Six weeks post-injection, all underwent renal biopsy, and FTY720-treatment started in ADR-rats (n = 8) and controls (n = 6). Others remained untreated. Rats were sacrificed after 12 weeks. Collagen type I (C1M) and III (C3M) degradation fragments were measured in blood and urine using ELISA. Kidneys were stained for various inflammatory and fibrotic markers.
Six weeks post-injection proteinuria increased (versus controls, P < 0.001) and although no accumulation of interstitial renal collagen type III (iColl3) was observed at this time, urinary C3M (uC3M) and C1M (uC1M) were significantly increased (both P < 0.001). At 12 weeks, uC3M (P < 0.001) and uC1M (P < 0.01) further increased in ADR-rats versus controls, just as fibronectin, PDGF-β receptor, hyaluronan (all P < 0.01), iColl3, PAS, myofibroblasts, macrophages and T-cells (all P < 0.05). FTY720-treatment reduced accumulation of immune cells, α-SMA+ myofibroblasts and PAS-score, but not iColl3 and uC3M. Correlation analyses indicated that uC3M and uC1M reflected and predicted tubulointerstitial fibrogenesis.
These data displayed urinary collagen breakdown products as sensitive early markers of interstitial fibrosis, preceding histological fibrotic changes, which might replace the invasive renal biopsy procedure to assess fibrosis. Anti-fibrotic FTY720 intervention reduced some fibrotic markers without affecting collagen type III metabolism.
Extracellular matrix (ECM) remodeling is a hallmark of the pathology of gastrointestinal disorders. Collagen type VI (COL6) is produced by fibroblasts, and the COL6 α3-chain has shown to be elevated ...in patients with ulcerative colitis (UC), Crohn's disease (CD) and colorectal cancer (CRC). Measuring COL6α3 in serum may therefore have potential as a biomarker for gastrointestinal disorders. The aims of this study were to develop and validate a competitive ELISA targeting a specific neo-epitope of COL6α3 and evaluate its associations with the gastrointestinal disorders UC, CD and CRC, in comparison to healthy controls. A monoclonal antibody was raised against a matrix metalloproteinase-2 and -9 specific cleavage site of COL6α3 (C6Mα3) and employed in a competitive enzyme-linked immunosorbent assay (ELISA). The assay was developed and technically validated. Levels of C6Mα3 were measured in serum from patients with UC (n = 58), CD (n = 44) and CRC (n = 39) and compared to healthy controls (n = 32). The levels of C6Mα3 were elevated in patients with UC, CD and CRC patients compared to healthy controls (all p < 0.0001). The area under the receiver operating characteristics (AUROC) curve for separation of patients with UC from healthy controls was 0.972 (95% CI: 0.925-1.020, p < 0.0001), with CD from healthy controls was 0.947 (95% CI: 0.885-1.009, p < 0.0001) and with CRC from healthy controls was 0.890 (95% CI: 0.809-0.972, p < 0.0001). We developed a technically robust assay targeting a fragment of COL6, which was elevated in serum from patients with UC, CD and CRC.
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