Platelet retention in inflamed glomeruli occurs via selective prolongation of interactions with immune cells

Hallmarks for Thrombotic and Hemorrhagic Risks in Chronic Kidney Disease Patients

Chronic kidney disease (CKD) is a global health issue causing a significant health burden. CKD patients develop thrombotic and hemorrhagic complications, and cardiovascular diseases are associated with increased hospitalization and mortality in this population. The hemostatic alterations are multifactorial in these patients; therefore, the results of different studies are varying and controversial. Endothelial and platelet dysfunction, coagulation abnormalities, comorbidities, and hemoincompatibility of the dialysis membranes are major contributors of hypo- and hypercoagulability in CKD patients. Due to the tendency of CKD patients to exhibit a prothrombotic state and bleeding risk, they require personalized clinical assessment to understand the impact of antithrombotic therapy. The evidence of efficacy and safety of antiplatelet and anticoagulant treatments is limited for end-stage renal disease patients due to their exclusion from major randomized clinical trials. Moreover, designing hemocompatible dialyzer membranes could be a suitable approach to reduce platelet activation, coagulopathy, and thrombus formation. This review discusses the molecular mechanisms underlying thrombotic and hemorrhagic risk in patients with CKD, leading to cardiovascular complications in these patients, as well as the evidence and guidance for promising approaches to optimal therapeutic management.

Both Classical and Non-Classical Monocytes Patrol Glomerular Capillaries and Promote Acute Glomerular Inflammation

Monocyte patrolling of the vasculature has been ascribed primarily to the non-classical monocyte subset. However, a recent study of the glomerular microvasculature provided evidence that both classical and non-classical monocytes undergo periods of intravascular retention and migration. Despite this, whether these subsets contribute differentially to acute glomerular inflammation is unknown. This study used glomerular multiphoton intravital microscopy to investigate the capacity of classical and non-classical monocytes to patrol the glomerular microvasculature and promote acute, neutrophil-dependent glomerular inflammation. In imaging experiments in monocyte reporter Cx3cr1gfp/+ mice, co-staining with anti-Ly6B or anti-Ly6C revealed that both non-classical monocytes [CX3C chemokine receptor 1-green fluorescent protein positive (CX3CR1-GFP+)] and classical monocytes (CX3CR1-GFP+ and Ly6B+ or Ly6C+) underwent prolonged (>10 minutes) retention and migration in the glomerular microvasculature. On induction of acute glomerulonephritis, in these behaviors were increased in classical but not non-classical monocytes. Using non-classical monocyte-deficient Csf1rCreNr4a1fl/fl mice, or anti-CCR2 to deplete classical monocytes, the removal of either subset reduced neutrophil retention and activation in acutely inflamed glomeruli, while the depletion of both subsets, via anti-CCR2 treatment in Csf1rCreNr4a1fl/fl mice, led to further reductions in neutrophil activity. In contrast, in a model of CD4+ T cell-dependent glomerulonephritis, the depletion of either monocyte subset failed to alter neutrophil responses. These findings indicate that both classical and non-classical monocytes patrol the glomerular microvasculature and promote neutrophil responses in acutely inflamed glomeruli.

Potential for modulation of platelet function via adenosine receptors during inflammation

Traditionally, platelets are known to play an important role in haemostasis and thrombosis; however, they serve also as important modulators of inflammation and immunity. Platelets secrete adhesion molecules and cytokines, interact with leukocytes and endothelium, and express toll-like receptors involved in a direct interaction with pathogens. Platelets express A2A and A2B subtypes of receptors for adenosine. The activation of these receptors leads to an increase in cAMP concentration in the cytoplasm, thereby resulting in inhibited secretion of pro-inflammatory mediators and reduced cell activation. Therefore, platelet adenosine receptors could be a potential target for inhibiting platelet activation and thus down-regulating inflammation or immunity. The biological effects of adenosine are short-lasting, because the compound is rapidly metabolized; hence, its lability has triggered efforts to synthesize new, longer-lasting adenosine analogues. In this article, we have reviewed the literature regarding the pharmacological potential of adenosine and other agonists of A2A and A2B receptors to affect platelet function during inflammation. LINKED ARTICLES: This article is part of a themed issue on Platelet purinergic receptor and non-thrombotic disease. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v181.4/issuetoc.

Removal of the endothelial surface layer via hyaluronidase does not modulate monocyte and neutrophil interactions with the glomerular endothelium

OBJECTIVE

The endothelial surface layer (ESL), a layer of macromolecules on the surface of endothelial cells, can both impede and facilitate leukocyte recruitment. However, its role in monocyte and neutrophil recruitment in glomerular capillaries is unknown.

METHODS

We used multiphoton intravital microscopy to examine monocyte and neutrophil behavior in the glomerulus following ESL disruption with hyaluronidase.

RESULTS

Constitutive retention and migration of monocytes and neutrophils within the glomerular microvasculature was unaltered by hyaluronidase. Consistent with this, inhibition of the hyaluronan-binding molecule CD44 also failed to modulate glomerular trafficking of these immune cells. To investigate the contribution of the ESL during acute inflammation, we induced glomerulonephritis via in situ immune complex deposition. This resulted in increases in glomerular retention of monocytes and neutrophils but did not induce marked reduction in the glomerular ESL. Furthermore, hyaluronidase treatment did not modify the prolonged retention of monocytes and neutrophils in the acutely inflamed glomerular microvasculature.

CONCLUSIONS

These observations indicate that, despite evidence that the ESL has the capacity to inhibit leukocyte-endothelial cell interactions while also containing adhesive ligands for immune cells, neither of these functions modulate trafficking of monocytes and neutrophils in steady-state or acutely-inflamed glomeruli.

The role of platelets in immune-mediated inflammatory diseases

Immune-mediated inflammatory diseases (IMIDs) are characterized by excessive and uncontrolled inflammation and thrombosis, both of which are responsible for organ damage, morbidity and death. Platelets have long been known for their role in primary haemostasis, but they are now also considered to be components of the immune system and to have a central role in the pathogenesis of IMIDs. In patients with IMIDs, platelets are activated by disease-specific factors, and their activation often reflects disease activity. Here we summarize the evidence showing that activated platelets have an active role in the pathogenesis and the progression of IMIDs. Activated platelets produce soluble factors and directly interact with immune cells, thereby promoting an inflammatory phenotype. Furthermore, platelets participate in tissue injury and promote abnormal tissue healing, leading to fibrosis. Targeting platelet activation and targeting the interaction of platelets with the immune system are novel and promising therapeutic strategies in IMIDs.

Thrombopoietin-Dependent Myelo-Megakaryopoiesis Fuels Thromboinflammation and Worsens Antibody-Mediated Chronic Renal Microvascular Injury

SIGNIFICANCE STATEMENT

Kidney-derived thrombopoietin (TPO) increases myeloid cell and platelet production during antibody-mediated chronic kidney disease (AMCKD) in a mouse model, exacerbating chronic thromobinflammation in microvessels. The effect is mirrored in patients with extracapillary glomerulonephritis associated with thromboinflammation, TGF β -dependent glomerulosclerosis, and increased bioavailability of TPO. Neutralization of TPO in mice normalized hematopoiesis, reduced chronic thromboinflammation, and ameliorated renal disease. The findings suggest that TPO is a relevant biomarker and a promising therapeutic target for patients with CKD and other chronic thromboinflammatory diseases.Neutralization of TPO in mice normalized hematopoiesis, reduced chronic thromboinflammation, and ameliorated renal disease. The findings suggest that TPO is a relevant biomarker and a promising therapeutic target for patients with CKD and other chronic thromboinflammatory diseases.

BACKGROUND

Chronic thromboinflammation provokes microvascular alterations and rarefaction, promoting organ dysfunction in individuals with various life-threatening diseases. Hematopoietic growth factors (HGFs) released by the affected organ may sustain emergency hematopoiesis and fuel the thromboinflammatory process.

METHODS

Using a murine model of antibody-mediated chronic kidney disease (AMCKD) and pharmacological interventions, we comprehensively monitored the response to injury in the circulating blood, urine, bone marrow, and kidney.

RESULTS

Experimental AMCKD was associated with chronic thromboinflammation and the production of HGFs, especially thrombopoietin (TPO), by the injured kidney, which stimulated and skewed hematopoiesis toward myelo-megakaryopoiesis. AMCKD was characterized by vascular and kidney dysfunction, TGF β -dependent glomerulosclerosis, and microvascular rarefaction. In humans, extracapillary glomerulonephritis is associated with thromboinflammation, TGF β -dependent glomerulosclerosis, and increased bioavailability of TPO. Analysis of albumin, HGF, and inflammatory cytokine levels in sera from patients with extracapillary glomerulonephritis allowed us to identify treatment responders. Strikingly, TPO neutralization in the experimental AMCKD model normalized hematopoiesis, reduced chronic thromboinflammation, and ameliorated renal disease.

CONCLUSION

TPO-skewed hematopoiesis exacerbates chronic thromboinflammation in microvessels and worsens AMCKD. TPO is both a relevant biomarker and a promising therapeutic target in humans with CKD and other chronic thromboinflammatory diseases.

[Recent research on platelet-leukocyte aggregates and their role in the pathogenesis of Kawasaki disease]

Activated platelets may interact with various types of leukocytes such as monocytes, neutrophils, dendritic cells, and lymphocytes, trigger intercellular signal transduction, and thus lead to thrombosis and synthesis of massive inflammatory mediators. Elevated levels of circulating platelet-leukocyte aggregates have been found in patients with thrombotic or inflammatory diseases. This article reviews the latest research on the formation, function, and detection methods of platelet-leukocyte aggregates and their role in the onset of Kawasaki disease, so as to provide new ideas for studying the pathogenesis of Kawasaki disease.

Studies on the metabolism and mechanism of acteoside in treating chronic glomerulonephritis

ETHNOPHARMACOLOGICAL RELEVANCE

Acteoside (ACT) is the main ingredient derived from the leaves of Rehmannia glutinosa (Dihuangye). Dihuangye has the function of clearing heat, replenishing qi and activating blood, nourishing yin and tonifying kidney in traditional Chinese medicine. Recent studies have demonstrated that Dihuangye can be used to treat nephritis and ACT is a promising antinephritic agent.

AIM OF THE STUDY

To clarify the metabolites of ACT in biological samples and investigate the renoprotective effect and mechanism of ACT in rats with chronic glomerulonephritis (CGN).

MATERIALS AND METHODS

In this study, the biotransformation of ACT in rat biological samples was clarified by quadrupole time-of-flight tandem mass spectrometry. The metabolites were validated by urine samples in nephropathy model rats. The effect of ACT and its metabolites was evaluated by glomerular podocyte injury due to high glucose. Based on an analysis of the ingredients in vivo, the potential therapeutic targets in the treatment of CGN were investigated by using network pharmacological analysis and molecular docking. Then, the renoprotective effect and mechanism of ACT were determined in rats in a passive Heymann nephritis (PHN) model.

RESULTS

A total of 49 metabolites of ACT were detected and identified. Meanwhile, 21 metabolites were detected in nephropathy model rats. ACT was absorbed rapidly and transferred from the kidney, and the metabolites were eliminated via urine. The whole process lasted approximately 8 h. ACT had a significant protective effect on glomerular podocytes damaged by high glucose and 3,4-dihydroxyphenylacetic acid might be the main metabolite of ACT underlying its functions in vivo. The network pharmacology and molecular docking results showed 84 ACT-CGN targets, among which MAPK1, HRAS, AKT1, EGFR, and others were a highly correlated. In the PHN rat model, ACT significantly reduced the 24-h urine protein and serum creatinine concentrations, suppressed the leukocyte CD18 expression levels, decreased the serum tumor necrosis factor α (TNF-α) levels and tended to reduce serum interleukin 6 (IL-6) levels. ACT significantly reduced the platelet aggregation rate and inhibited the proliferative activity of splenic lymphocytes in response to the mitogen concanavalin A. Meanwhile, ACT inhibited transforming growth factor-β and fibronectin expression in renal tissues and dose-dependently inhibited TNF-α and IL-6 production in RAW264.7 mouse macrophages at doses ranging from 1.8 to 1330 μg/mL.

CONCLUSIONS

ACT had therapeutic effects on PHN rats, and its mechanism might be related to the inhibition of intercellular or intercellular-matrix adhesion, suppression of inflammatory response, regulation of immune function, improvement of tissue hemodynamics and hemorheology, and relief of fibrotic lesions.

C-type lectin-like receptor (CLEC)-2, the ligand of podoplanin, induces morphological changes in podocytes

Podoplanin (PDPN) is intensely expressed on the podocyte membrane in an evolutionally conserved manner. CLEC-2, the endogenous ligand of PDPN, is highly expressed in platelets and also exists in a soluble form in plasma. Normally, podocytes are sequestered from CLEC-2, but when the glomerular barrier is injured, podocytes gain access to CLEC-2. We tested the effects of CLEC-2 in podocytes in vitro and in vivo. Cultured podocytes treated with Fc-CLEC-2 demonstrated that CLEC-2 induced the dephosphorylation of ezrin, radixin, and moesin (ERM) proteins. Podocytes treated with Fc-CLEC-2 also showed the dissociation of F-actin filaments from PDPN, F-actin degradation, detachment, and round morphology. Next, we perfused normal mouse kidney in vivo with FLAG-CLEC-2. CLEC-2 induced dephosphorylation of ERM and widening of the foot processes of podocytes. Platelets were detected by immunostaining for CD41 in the urine of mice with podocyte injury, indicating that podocytes can encounter platelets when glomeruli are injured. Collectively, these observations suggest that when platelets leak through the injured glomeruli, CLEC-2 from the platelets acts on PDPN in podocytes and induces morphological change and detachment, which may further aggravate podocyte injury. Thus, PDPN on podocytes may work as a leaked-platelet sensor.

Immune cell behaviour and dynamics in the kidney - insights from in vivo imaging

The actions of immune cells within the kidney are of fundamental importance in kidney homeostasis and disease. In disease settings such as acute kidney injury, anti-neutrophil cytoplasmic antibody-associated vasculitis, lupus nephritis and renal transplant rejection, immune cells resident within the kidney and those recruited from the circulation propagate inflammatory responses with deleterious effects on the kidney. As in most forms of inflammation, intravital imaging - particularly two-photon microscopy - has been critical to our understanding of immune cell responses in the renal microvasculature and interstitium, enabling visualization of immune cell dynamics over time rather than statically. These studies have demonstrated differences in the recruitment and function of these cells from those in more conventional vascular beds, and provided a wealth of information on the actions of blood-borne immune cells such as neutrophils, monocytes and T cells, as well as kidney-resident mononuclear phagocytes, in a range of diseases affecting different kidney compartments. In particular, in vivo imaging has furthered our understanding of leukocyte function within the glomerulus in acute glomerulonephritis, and in the tubulointerstitium and interstitial microvasculature during acute kidney injury and following transplantation, revealing mechanisms of immune surveillance, antigen presentation and inflammation in the kidney.

The Chemokine CXCL7 Is Related to Angiogenesis and Associated With Poor Prognosis in Colorectal Cancer Patients

Objective

The present study was designed to investigate the role of the chemokine CXCL7 in angiogenesis and explore its prognostic value in colorectal cancer (CRC).

Methods

A total of 160 CRC patients who had undergone surgery were included in this study, and staged according to the guidelines of the AJCC, 7^th Edition. Expression of CXCL7 and VEGF was detected by immunohistochemical (IHC) staining and divided into high and low expression subgroups. The correlation between CXCL7 and VEGF expression was evaluated by Spearman’s rank-correlation coefficient. Prognosis based on CXCL7 and VEGF was evaluated using the Cox proportional hazards regression model and a nomogram of 5-year overall survival (OS) time.

Results

CXCL7 was highly expressed in tumor tissues (65.63% vs 25.00% in paracancerous tissue, P < 0.001), as was VEGF. CXCL7 and VEGF expression correlated well with N and TNM stage cancers (all P < 0.001). Importantly, CXCL7 was positively correlated with VEGF expression in CRC tissues. CXCL7 was an independent predictor of poor OS of CRC patients (HR = 2.216, 95% CI: 1.069-4.593, P = 0.032), and co-expression of CXCL7 and VEGF of predicted poor OS of 56.96 months.

Conclusion

Expression of CXCL7 correlated with VEGF and was associated with poor clinical outcomes in CRC patients.

Tetraspanin CD53 modulates lymphocyte trafficking but not systemic autoimmunity in Lyn-deficient mice

The leukocyte-restricted tetraspanin CD53 has been shown to promote lymphocyte homing to lymph nodes (LNs) and myeloid cell recruitment to acutely inflamed peripheral organs, and accelerate the onset of immune-mediated disease. However, its contribution in the setting of chronic systemic autoimmunity has not been investigated. We made use of the Lyn^-/- autoimmune model, generating Cd53^-/- Lyn^-/- mice, and compared trafficking of immune cells into secondary lymphoid organs and systemic autoimmune disease development with mice lacking either gene alone. Consistent with previous observations, absence of CD53 led to reduced LN cellularity via reductions in both B and T cells, a phenotype also observed in Cd53^-/- Lyn^-/- mice. In some settings, Cd53^-/- Lyn^-/- lymphocytes showed greater loss of surface L-selectin and CD69 upregulation above that imparted by Lyn deficiency alone, indicating that absence of these two proteins can mediate additive effects in the immune system. Conversely, prototypical effects of Lyn deficiency including splenomegaly, plasma cell expansion, elevated serum immunoglobulin M and anti-nuclear antibodies were unaffected by CD53 deficiency. Furthermore, while Lyn^-/- mice developed glomerular injury and showed elevated glomerular neutrophil retention above than that in wild-type mice, absence of CD53 in Lyn^-/- mice did not alter these responses. Together, these findings demonstrate that while tetraspanin CD53 promotes lymphocyte trafficking into LNs independent of Lyn, it does not make an important contribution to development of autoimmunity, plasma cell dysfunction or glomerular injury in the Lyn^-/- model of systemic autoimmunity.

Platelet and Erythrocyte Extravasation across Inflamed Corneal Venules Depend on CD18, Neutrophils, and Mast Cell Degranulation

Platelet extravasation during inflammation is under-appreciated. In wild-type (WT) mice, a central corneal epithelial abrasion initiates neutrophil (PMN) and platelet extravasation from peripheral limbal venules. The same injury in mice expressing low levels of the β₂-integrin, CD18 (CD18_hypo mice) shows reduced platelet extravasation with PMN extravasation apparently unaffected. To better define the role of CD18 on platelet extravasation, we focused on two relevant cell types expressing CD18: PMNs and mast cells. Following corneal abrasion in WT mice, we observed not only extravasated PMNs and platelets but also extravasated erythrocytes (RBCs). Ultrastructural observations of engorged limbal venules showed platelets and RBCs passing through endothelial pores. In contrast, injured CD18_hypo mice showed significantly less venule engorgement and markedly reduced platelet and RBC extravasation; mast cell degranulation was also reduced compared to WT mice. Corneal abrasion in mast cell-deficient (Kit^W-sh/W-sh) mice showed less venule engorgement, delayed PMN extravasation, reduced platelet and RBC extravasation and delayed wound healing compared to WT mice. Finally, antibody-induced depletion of circulating PMNs prior to corneal abrasion reduced mast cell degranulation, venule engorgement, and extravasation of PMNs, platelets, and RBCs. In summary, in the injured cornea, platelet and RBC extravasation depends on CD18, PMNs, and mast cell degranulation.

Mired in the glomeruli: witnessing live neutrophil recruitment in the kidney

Inflammation of the kidney is a key contributor to proliferative glomerulonephritis, and kidney damage during glomerulonephritis can lead to renal failure. The immune response associated with glomerulonephritis episodes is a major determinant of patient outcomes, and understanding this response is paramount for effective therapeutic treatment. Neutrophils are the first responders to sites of infection or tissue injury and are a significant cellular infiltrate during proliferative glomerulonephritis. This immune cell was initially recognized as a "blunt" nonspecific effector cell that was recruited to kill pathogens and then die quickly. However, recent studies have shown that the behavior and function of neutrophils are substantially more complex. Neutrophil recruitment to inflammatory sites must be carefully regulated so that these potent cells accurately arrive at tissue sites and perform their functions without nonspecific injury to other locations. As the kidney contains unique microvasculature befitting their specialized role in blood filtration, the recruitment of neutrophils in the renal environment differs from other organs. This Mini-Review will describe how advances in live-animal (intravital) imaging led to the discovery of novel recruitment pathways in the kidney, particularly in the glomeruli, and highlight these differences to canonical neutrophil recruitment. In addition, molecular engagement of surface molecules that lead to intracellular signaling, which is followed by neutrophil capture in the glomeruli, is also briefly discussed. Finally, the contribution of other immune cells in renal neutrophil recruitment, the fate of the emigrated neutrophils after inflammation, and the relevance of mouse models compared with human glomerulonephritides will also be explored.

Serum Chemokine CXCL7 as a Potential Novel Biomarker for Obstructive Colorectal Cancer

Due to the lack of typical symptoms and signs and sensitive indicators for early diagnosis of obstructive colorectal cancer (OCRC), it is critically needed to find new novel biomarkers to ameliorate the management of OCRC patients. In this study, 472 blood samples were collected and measured by enzyme-linked immunosorbent assay (ELISA) to investigate the value of serum chemokine ligand 7 (CXCL7) in diagnosis and prognosis for OCRC patients. The median concentrations of CXCL7 in non-OCRC and OCRC were both higher than that in controls (both P < 0.05). Importantly, the median serum concentration of CXCL7 in OCRC was also higher than that in non-OCRC (P < 0.001). In all OCRC patients, the area under the curve (AUC) of CXCL7 was 0.918 with a sensitivity of 86.54% and a specificity of 81.87%. Similarly, the AUC of CXCL7 was 0.684 when the diagnostic test was performed between OCRC and CRC patients. CXCL7 had a higher AUC than other markers. The concentration of CXCL7 in 40 postoperative OCRC patients was higher than normal people and lower than preoperative patients. The median survival time was 62.00 months and the 5-year overall survival (OS) rate of the patients was 51.80% in all 155 OCRC patients. Multivariate Cox proportional hazard regression model analysis showed that high CXCL7 in serum was independent factors associated with poor OS of OCRC patients (HR = 2.216, P = 0.032). These results demonstrate that serum CXCL7 may be a potential biomarker both in diagnosis and prognosis for OCRC patients.

Platelets: Mechanistic and Diagnostic Significance in Transplantation

Purpose of Review

In addition to their function in coagulation, platelets recently have been recognized as an important component of innate immune responses. This review relates salient immune functions of platelets to transplants.

Recent Findings

Platelets are critical bridges between vascular endothelium and leukocytes. Real-time imaging of platelets has demonstrated that platelets rapidly adhere to vascular endothelium and form a nidus for attachment of neutrophils and then monocytes. However, the majority of platelets subsequently release from endothelium and return to the circulation in an activated state. These recycled platelets have the potential to transport proteins and RNA from the graft to the recipient. Some of the platelets that return to the circulation are attached to leukocytes.

Summary

Platelets have the potential to modulate many elements of the graft and the immune response from the time of organ retrieval through ischemia-reperfusion to acute and chronic rejection. Beyond mechanistic considerations, assays that detect changes in platelet protein or RNA expression could be used to monitor early inflammatory responses in transplants.

Serum Chemokine CXCL7 as a Diagnostic Biomarker for Colorectal Cancer

Identification of effective biomarkers is crucial for monitoring the treatment and remission of colorectal cancer (CRC) and improving survival. It is particularly important to diagnose CRC before the tumor metastasizes (stage I–II disease) where possible, to provide the greatest opportunity for patient recovery. Here, we evaluated the clinical value of serum chemokine (C-X-C) ligand 7 (CXCL7) concentration as a biomarker for CRC diagnosis. An enzyme-linked immunosorbent assay was used to measure CXCL7 concentration in 560 serum samples from patients with CRC and controls. Logistic regression and receiver operating characteristic (ROC) curve analysis was used to assess the diagnostic efficacy and build mathematical diagnostic models. The concentration of CXCL7 in the CRC group was significantly higher than that in the control group (P < 0.001), with an area under the ROC curve (AUC) value of 0.862 [95% confidence interval (CI): 0.831–0.890]. Further, the AUC of a regression model including the markers carcinoembryonic antigen (CEA), carbohydrate antigen 19-9 (CA19-9), and carbohydrate antigen 125 (CA125), along with CXCL7, was 0.933 (95% CI: 0.909–0.952). For stage I–II tumors, CXCL7 had the highest AUC (0.823, 95% CI: 0.783–0.858) among the four individual biomarkers. The AUC value for combination model analysis of samples from patients with stage I–II tumors was 0.904 (95% CI: 0.872–0.930), with a sensitivity of 82.76% and a specificity of 87.14%, and an optimal cut-off value of 2.66. AUC values for application of the regression model in subgroup analysis were 0.947 (0.917–0.968) and 0.919 (0.874–0.951) for males and females, respectively. These results suggest that CXCL7 has potential as a serum diagnostic biomarker for detection of CRC. Importantly, the combination of CXCL7, CEA, CA125, and CA19-9 may facilitate diagnosis of CRC with relatively high sensitivity and specificity.

Clinical Trial Registration Number: LS2017001.