Leucine-rich alpha-2 glycoprotein in combination with C-reactive protein for predicting endoscopic activity in Crohn’s disease: a single-centre, cross-sectional study

Leucine-rich alpha-2 glycoprotein (LRG) is a novel biomarker for monitoring disease activity in inflammatory bowel disease (IBD). The aim of this study was to evaluate its utility in monitoring disease activity. In this retrospective study based on case records between August 2020 and July 2021 at our two centers, we examined the correlation between serum levels of LRG and C-reactive protein (CRP) with disease activity in IBD patients. Background factors related to serum LRG levels were also analyzed. Overall, 47 Crohn's disease (CD) and 123 ulcerative colitis (UC) patients were evaluated. In patients with CD, LRG and CRP levels correlated with Harvey-Bradshaw Index (HBI) and Simple Endoscopic Score for CD (SES-CD) (LRG and HBI, r = 0.397; LRG and SES-CD, r = 0.637; CRP and HBI, r = 0.253; CRP and SES-CD, r = 0.332). In patients with UC, LRG and CRP significantly correlated with the partial Mayo score (PMS) and Mayo endoscopic subscore (MES) (LRG and PMS, r = 0.3; CRP and PMS, r = 0.282; LRG and MES, r = 0.424; CRP and MES, r = 0.459). In CD patients with normal CRP, serum LRG level was significantly higher in those with mucosal inflammation than in those with mucosal healing (16.4 vs. 10.7 μg/ mL). Stenosis was associated with serum LRG levels in CD group using multiple regression analysis. Therefore, LRG is a useful biomarker for monitoring disease activity and mucosal inflammation, and indicates the status of intestinal stenosis in IBD patients.

BackgroundThe usefulness of leucine-rich alpha 2 glycoprotein (LRG) to evaluate Crohn’s disease (CD) activity differs among various intestinal lesions. We aimed to evaluate the association between endoscopic disease activity based on the Simple Endoscopic Score for Crohn’s disease (SES-CD) and LRG level separately for small intestinal and colonic lesions.MethodsWe examined the correlation between LRG level and SES-CD and performed receiver operating characteristic (ROC) analysis to determine the LRG cutoff value in 141 patients who underwent endoscopy (total 235 measurements). Furthermore, the LRG cutoff value was analyzed by comparing small intestinal and colonic lesions.ResultsLRG levels were significantly higher in patients without mucosal healing than in those with mucosal healing (15.9 μg/mL vs 10.5 μg/mL, P < .0001). The LRG cutoff value for mucosal healing was 14.3 μg/mL (area under the ROC curve [AUC]: 0.80; sensitivity: 0.89; specificity: 0.63). The LRG cutoff value for patients with type L1 was 14.3 μg/mL (sensitivity: 0.91; specificity: 0.53), and that for patients with type L2 was 14.0 μg/mL (sensitivity: 0.95; specificity: 0.73). The diagnostic performance (AUC) of LRG and C-reactive protein (CRP) for mucosal healing was, respectively, 0.75 and 0.60 (P = 0.01) in patients with type L1 and 0.80 and 0.85 (P = 0.90) in patients with type L2.ConclusionsThe optimal LRG cutoff value for evaluating mucosal healing in CD is 14.3 μg/mL. LRG is more useful than CRP for predicting mucosal healing in patients with type L1. The superiority of LRG to CRP differs between small intestinal and colonic lesions.

Reliable biomarkers for monitoring disease activity have not been clinically established in ulcerative colitis (UC). This study aimed to investigate whether levels of serum leucine-rich alpha-2 glycoprotein (LRG), identified recently as a potential disease activity marker in Crohn's disease and rheumatoid arthritis, correlate with disease activity in UC. Serum LRG concentrations were determined by enzyme-linked immunosorbent assay (ELISA) in patients with UC and healthy controls (HC) and were evaluated for correlation with disease activity. Expression of LRG in inflamed colonic tissues from patients with UC was analyzed by western blotting and immunohistochemistry. Interleukin (IL)-6-independent induction of LRG was investigated using IL-6-deficient mice by lipopolysaccharide (LPS)-mediated acute inflammation and dextran sodium sulfate (DSS)-induced colitis. Serum LRG concentrations were significantly elevated in active UC patients compared with patients in remission (P < 0.0001) and HC (P < 0.0001) and were correlated with disease activity in UC better than C-reactive protein (CRP). Expression of LRG was increased in inflamed colonic tissues in UC. Tumor necrosis factor alpha (TNF-α), IL-6, and IL-22, serum levels of which were elevated in patients with active UC, could induce LRG expression in COLO205 cells. Serum LRG levels were increased in IL-6-deficient mice with LPS-mediated acute inflammation and DSS-induced colitis. Serum LRG concentrations correlate well with disease activity in UC. LRG induction is robust in inflamed colons and is likely to involve an IL-6-independent pathway. Serum LRG is thus a novel serum biomarker for monitoring disease activity in UC and is a promising surrogate for CRP.

BACKGROUNDAchievement of endoscopic healing (EH) is significant in the clinical practice of inflammatory bowel disease as it is correlated with improved prognosis. Existing biomarkers, including C-reactive protein (CRP), have relatively low accuracy for predicting EH, especially in small intestinal lesions in Crohn’s disease (CD); thus, noninvasive and more accurate biomarkers are required. Leucine-rich alpha-2 glycoprotein (LRG), a 50-kD protein, is produced under inflammatory conditions and has been reported to be useful in assessing disease activity in inflammatory bowel disease. However, the usefulness of LRG in small intestinal lesions in CD remains inconclusive.AIMTo determine the usefulness of LRG for EH in small bowel lesions in CD and compare it with CRP.METHODSThis study included 133 consecutive patients with CD who underwent balloon-assisted enteroscopy between June 2021 and March 2024 at Shiga University of Medical Science Hospital (Otsu, Japan). We retrospectively analyzed endoscopic scores in each of the ileum and colon and four markers including LRG, CRP, albumin, and Harvey-Bradshaw index (HBI). Spearman’s rank correlation coefficient and receiver operating characteristic analysis were performed.RESULTSEither active ileal or colonic lesions exhibited significant differences in LRG, CRP, albumin, and HBI compared with EH. CRP, albumin, and HBI showed a worse correlation with endoscopic activity in the ileum than that in the colon; however, LRG did not show a worse correlation (colon, r = 0.5218; ileum, r = 0.5602). Receiver operating characteristic analysis revealed that LRG for EH in the ileum and colon had the same cutoff values of 12.4 μg/mL. Comparing the areas under the curve of LRG and CRP for predicting EH in the ileum revealed a significantly higher areas under the curve of LRG (95% confidence interval, 0.017-0.194; P = 0.024), whereas the two showed no significant difference in the colon.CONCLUSIONLRG is a useful biomarker in assessing the endoscopic activity of CD and is more useful than CRP in the small intestine.

This study aimed to investigate whether sepsis markers act as biomarkers of ulcerative colitis (UC) and Crohn's disease (CD). The identification of noninvasive biomarkers for inflammatory bowel disease (IBD) is advantageous. This prospective observational study investigated whether the sepsis markers, interleukin-6 (IL-6), presepsin (PSEP), procalcitonin (PCT), and pentraxin 3 (PTX3), act as biomarkers of UC and CD. Patients with UC or CD underwent endoscopy and assessment of the abovementioned sepsis markers, C-reactive protein (CRP), and leucine-rich alpha 2 glycoprotein (LRG). We prospectively examined the association of these markers with clinical activity and endoscopic scores, including the Mayo endoscopic subscore (MES) and simple endoscopic score for Crohn's disease (SES-CD). Eighty-eight patients with UC and 49 patients with CD were enrolled. MES significantly correlated with LRG, CRP, IL-6, PSEP, and PTX3 in patients with UC. SES-CD significantly correlated with LRG, CRP, IL-6, and PTX3 in patients with CD. In UC, MES to 3 groups showed significantly higher LRG, CRP, and IL-6 levels than the MES 0 to 1 groups. The LRG, CRP, IL-6, PSEP, and PTX3 levels were significantly higher in the SES-CD ≥3 group than in the SES-CD ≤2 group. IL-6 in UC and IL-6, PSEP, and PTX3 in CD are potential biomarkers. Overall, our findings could promote better management of IBD.

BackgroundThis multicenter prospective study (UMIN000019958) aimed to evaluate the usefulness of serum leucin-rich alpha-2 glycoprotein (LRG) levels in monitoring disease activity in inflammatory bowel disease (IBD).MethodsPatients with moderate-to-severe IBD initiated on adalimumab therapy were enrolled herein. Serum LRG, C-reactive protein (CRP), and fecal calprotectin (fCal) levels were measured at week 0, 12, 24, and 52. Colonoscopy was performed at week 0, 12, and 52 for ulcerative colitis (UC), and at week 0, 24, and 52 for Crohn’s disease (CD). Endoscopic activity was assessed using the Simple Endoscopic Score for Crohn’s Disease (SES-CD) for CD and the Mayo endoscopic subscore (MES) for UC.ResultsA total of 81 patients was enrolled. Serum LRG levels decreased along with improvements in clinical and endoscopic outcomes upon adalimumab treatment (27.4 ± 12.6 μg/ml at week 0, 15.5 ± 7.7 μg/ml at week 12, 15.7 ± 9.6 μg/ml at week 24, and 14.5 ± 6.8 μg/ml at week 52), being correlated with endoscopic activity at each time point (SES-CD: r = 0.391 at week 0, r = 0.563 at week 24, r = 0.697 at week 52; MES: r = 0.534 at week 0, r = 0.429 at week 12, r = 0.335 at week 52). Endoscopic activity better correlated with LRG compared to CRP and fCal on pooled analysis at all time points (SES-CD: LRG: r = 0.636, CRP: r = 0.402, fCal: r = 0.435; MES: LRG: r = 0.568, CRP: 0.389, fCal: r = 0.426).ConclusionsSerum LRG is a useful biomarker of endoscopic activity both in CD and UC during the adalimumab treatment.

In the era of ‘treat-to-target’ management of inflammatory bowel disease (IBD), non-invasive methods of disease assessment are increasingly utilised [1]. The rising incidence of IBD in newly industrialised countries poses additional challenges where access to ‘traditional’ methods of disease assessment, such as ileocolonoscopy, is more limited due to resource constraints [2]. Intestinal ultrasound (IUS) provides a real-time assessment of transmural inflammation and is useful for proactive and reactive monitoring of IBD [3-5]. Despite this, IUS is limited by inter-operator variability, the need for specialised training, and relatively limited worldwide availability [5]. Existing biomarkers such as C-reactive protein (CRP) and faecal calprotectin are often used with or without IUS [3] but these markers either lack sensitivity/specificity for active IBD or are limited by patient acceptability (e.g., for collection of faecal samples). Leucine-rich alpha-2 glycoprotein (LRG) is an alternative serum biomarker that is a predictor of both clinical and endoscopic activity in patients with Crohn's disease (CD) [6, 7]. Komatsu et al. [8] have expanded on existing evidence for LRG and have investigated it as a potential alternative to IUS in assessing transmural inflammation in CD. This single-centre, retrospective analysis of 97 patients and 213 IUS studies assessed the correlations between LRG and CRP with five validated IUS scores of CD activity. LRG was a significantly superior predictor of CD activity in most IUS indices when compared with CRP and the Crohn's Disease Activity Index, in all patients, and those in clinical remission. These findings are consistent with a similar study by Takenaka et al. [9] which evaluated the correlation between LRG and magnetic resonance enterography in CD. The findings by Komatsu et al. [8] have promoted LRG as a feasible method of proactively assessing CD activity in patients who are clinically well. This allows for more timely healthcare interventions for individuals with ‘silent CD’ who have clinically quiescent disease but have an ongoing inflammatory burden and are at increased risk for adverse long-term health outcomes [10]. Despite the potential benefits of LRG as a biomarker in CD, several questions remain unanswered. The utility of LRG in individuals earlier in their disease course compared with a median disease duration of 10 years in this study by Komatsu et al. [8] is unclear. Furthermore, the associations of LRG with longitudinal CD outcomes, such as incident strictures or penetrating complications, hospitalisations, need for IBD surgery, and disability need closer interrogation. The utility of combining LRG with IUS in assessing such longer term health outcomes also requires assessment. LRG remains a relatively under-utilised biomarker worldwide. Further investigation of its accuracy in different ethnicities and regions, along with cost-effectiveness analyses in high- and low-income countries, will help to strengthen its position in the armamentarium of tools to assess IBD. In conclusion, LRG correlates well with IUS findings in patients with CD and could become a useful biomarker for proactive monitoring of transmural inflammation in IBD. Anna Mitchell: conceptualization, writing – original draft, writing – review and editing. Akhilesh Swaminathan: conceptualization, writing – original draft, writing – review and editing. The authors have nothing to report. A.S. has received honoraria for educational activities from Janssen and Celltrion (unrelated to this manuscript). This article is linked to Komatsu et al papers. To view these articles, visit https://doi.org/10.1111/apt.18430 and https://doi.org/10.1111/apt.18493. The authors have nothing to report.

Leucine-rich alpha-2 glycoprotein (LRG) is a novel serum biomarker for inflammation in inflammatory bowel disease (IBD). This prospective study aimed to compare the value of LRG with C-reactive protein (CRP) and fecal calprotectin for evaluating clinical and endoscopic disease activity in patients with IBD. At entry, clinical and endoscopic disease activity was assessed in 267 patients with IBD (ulcerative colitis [UC] 203; Crohn's disease [CD] 64), and the levels of LRG, CRP and fecal calprotectin were measured. The accuracy of the biomarkers for the detection of clinical and endoscopic disease activity was determined by the area under the receiver operating characteristic curve. Leucine-rich alpha-2 glycoprotein showed a significant relationship with the clinical and endoscopic severity in both UC and CD (both diseases, P < .0001). In the clinical assessment of UC, the accuracy of LRG was significantly higher than that of CRP (0.73 vs 0.63; P < .001). In the endoscopic assessment of UC, the accuracy of LRG was significantly higher than that of CRP (P = .01), but it was significantly lower than that of fecal calprotectin (P = .009; LRG, 0.80; CRP, 0.72; fecal calprotectin, 0.91). In the clinical and endoscopic assessment of CD, the accuracy was not significantly different between the biomarkers (clinical activity: LRG, 0.71; CRP, 0.64; fecal calprotectin, 0.66; in endoscopic activity: LRG, 0.79; CRP, 0.78; fecal calprotectin, 0.81). Leucine-rich alpha-2 glycoprotein is a reliable serum biomarker for the assessment of clinical and endoscopic disease activity in patients with IBD. It can be an alternative to CRP for the assessment of UC.

BACKGROUND The treatment goals for inflammatory bowel disease, including Crohn's disease (CD), have shifted from clinical remission to mucosal healing. However, frequent endoscopies burden patients. Leucine-rich alpha 2 glycoprotein (LRG), produced by hepatocytes, neutrophils, and the intestinal epithelium, is more gut-specific than C-reactive protein (CRP). We examined whether LRG, as a biomarker, can detect small intestinal mucosal healing in CD patients, especially in those who are CRP-negative. METHOD 1) This study examined CD patients who visited our department from May 2021 to April 2023, had LRG measured, and underwent image evaluation using capsule endoscopy or balloon-assisted endoscopy. We analyzed their clinical background, looked for a correlation between LRG and CRP, assessed the ROC-AUC of LRG and CRP for mucosal healing, and measured the LRG and CRP cutoff values to determine mucosal healing. 2) Next, in CRP-negative CD patients, we analyzed the ROC-AUC of LRG for mucosal healing and LRG cutoff value to determine mucosal healing. Endoscopic evaluation was done within 3 months before and after LRG measurement. Absent open ulcers indicated mucosal healing. The upper limit of normal CRP value was &amp;lt;3 mg/L. We used the Spearman correlation coefficient to determine the correlation. RESULTS 1) Here, 67 CD patients were analyzed; 43 (64%) were men. The median age (range) of onset was 25.6 (3-57) years. The median disease duration (range) was 7.6 (0-27) years. B1, B2, and B3 of Montreal Classification were established in 31 (46.2%), 21 (31.3%), and 15 (22.3%) patients, respectively. The median (range) of LRG was 21.7 (7.6-67.4) μg/mL. The median (range) of CRP was 10.8 (0.0-86.9) mg/L. LRG and CRP were strongly correlated (r=0.878, p&amp;lt;0.001). The ROC-AUC of LRG for mucosal healing was 0.839 (95% confidence interval [CI] 0.760-0.918). LRG cutoff value for discriminating mucosal healing was 15.5 μg/mL (sensitivity 77%, specificity 75%). The ROC-AUC of CRP for mucosal healing was 0.811 (95% CI 0.721-0.900). The CRP cutoff value to differentiate mucosal healing was 0.9 mg/L (sensitivity 55%, specificity 90%). 2) Forty CRP-negative CD patients were analyzed; 23 (57%) were men. The median age (range) of onset was 21.9 (3-57) years. The median disease duration (range) was 7.0 (0-27) years. B1, B2, and B3 of Montreal Classification were established in 17 (42.5%), 12 (30.0%), and 11 (27.5%) patients, respectively. The median (range) of LRG was 12.3 (7.6-23.5) μg/mL. The ROC-AUC of LRG for mucosal healing was 0.817 (95% CI 0.696-0.938). The LRG cutoff value to differentiate mucosal healing was 14.1 μg/mL (sensitivity 61%, specificity 76%). CONCLUSION LRG may be a better biomarker than CRP for assessing endoscopic remission of the small intestinal mucosa in CD. In CRP-negative CD patients, LRG level of ≥14.1 μg/mL could indicate small intestinal ulcers.

The clinical usefulness of serum leucine-rich alpha-2 glycoprotein (LRG) levels as a surrogate marker of endoscopic activity including postoperative recurrence in patients with Crohn’s disease (CD) remains unclear, and LRG production in the small intestinal mucosa has not been explored. The present study investigated the usefulness of serum LRG to ascertain endoscopic activity, the secretion of LRG from the small intestinal mucosa, and the significance of LRG as a predictor of postoperative disease course. We included 364 patients who underwent transanal endoscopy at Osaka University Hospital. Serum LRG correlated highly with endoscopic severity (LRG, r = 0.65; CRP, r = 0.37) and reflected strictly moderate endoscopic activity better than serum CRP. Especially, serum LRG reflected mucosal healing even in patients whose inflammation was confined to the small intestine. In multivariate analyses, serum LRG was an independent factor influencing mucosal healing. LRG was more strongly expressed in the inflamed mucosa of the small intestine compared with that in uninflamed mucosa, and serum LRG was more strongly correlated with postoperative small intestinal recurrence severity than CRP (LRG, r = 0.62; CRP, r = 0.32). In conclusion, serum LRG is a useful surrogate marker of endoscopic CD severity and activity, with increased LRG expression in the small bowel predicting postoperative recurrence.

BackgroundAsthma is a chronic inflammatory disease of airways, but an ideal biomarker that accurately reflects ongoing airway inflammation has not yet been established. The aim of this study was to examine the potential of sputum leucine-rich alpha-2 glycoprotein (LRG) as a new biomarker for airway inflammation in asthma.MethodsWe obtained induced sputum samples from patients with asthma (N = 64) and healthy volunteers (N = 22) and measured LRG concentration by sandwich enzyme-linked immunosorbent assay (ELISA). Ovalbumin (OVA)-induced asthma model mice were used to investigate the mechanism of LRG production during airway inflammation. The LRG concentrations in the bronchoalveolar lavage fluid (BALF) obtained from mice were determined by ELISA and mouse lung sections were stained with anti-LRG antibody and periodic acid-Schiff (PAS) reagent.ResultsSputum LRG concentrations were significantly higher in patients with asthma than in healthy volunteers (p = 0.00686). Consistent with patients’ data, BALF LRG levels in asthma model mice were significantly higher than in control mice (p = 0.00013). Immunohistochemistry of lung sections from asthma model mice revealed that LRG was intensely expressed in a subpopulation of bronchial epithelial cells, which corresponded with PAS-positive mucus producing cells.ConclusionThese findings suggest that sputum LRG is a promising biomarker of local inflammation in asthma.

Background/AimsEndoscopic activity confirmed by enteroscopy is associated with poor clinical outcome in Crohn’s disease (CD). We investigated which of the existing biomarkers best reflects endoscopic activity in CD patients including the small bowel, and whether their combined use can improve accuracy.MethodsOne hundred and four consecutive patients with ileal and ileocolonic type CD who underwent balloon-assisted enteroscopy (BAE) from October 2021 to August 2022 were enrolled, with clinical and laboratory data prospectively collected and analyzed.ResultsHemoglobin, platelet count, C-reactive protein, leucine-rich alpha-2 glycoprotein (LRG), fecal calprotectin, and fecal hemoglobin all showed significant difference in those with ulcers found on BAE. LRG and fecal calprotectin showed the highest areas under the curve (0.841 and 0.853) for detecting ulcers. LRG showed a sensitivity of 78% and specificity of 80% at a cutoff value of 13 μg/mL, whereas fecal calprotectin showed a sensitivity of 91% and specificity of 67% at a cutoff value of 151 μg/g. Dual positivity for LRG and fecal calprotectin, as well as LRG and fecal hemoglobin, both predicted ulcers with an improved specificity of 92% and 100%. A positive LRG or fecal calprotectin/hemoglobin showed an improved sensitivity of 96% and 91%. Positivity for LRG and either of the fecal biomarkers was associated with increased risk of hospitalization, surgery, and relapse.ConclusionsThe biomarkers LRG, fecal calprotectin, and fecal hemoglobin can serve as noninvasive and accurate tools for assessing activity in CD patients confirmed by BAE, especially when used in combination.

Mucosal healing, confirmed by endoscopic evaluation, is the long-term goal of treatment for Crohn's disease (CD). Leucine-rich alpha-2 glycoprotein (LRG) is a new serum biomarker correlated with disease activity in inflammatory bowel disease. However, studies evaluating its relationship with CD, particularly in the context of small intestinal lesions, are scarce. The aim of this study was to investigate the accuracy of LRG in assessing endoscopic activity, especially remission, in patients with CD. Between July 2020 and March 2021, 72 patients with CD who underwent LRG testing and double-balloon endoscopy at the same time were included. Endoscopic activity was evaluated using the applied Simple Endoscopic Score for Crohn's disease, including small intestine lesions. The relationship of LRG with clinical symptoms and endoscopic activity was assessed, and its predictive accuracy was evaluated. Leucine-rich alpha-2 glycoprotein showed a significant positive correlation with endoscopic activity (r = 0.619, P < .001), even in patients with active lesions in the small intestine (r = 0.626, P < .001). Multivariate logistic regression revealed that LRG was the only factor associated with endoscopic remission. An LRG cutoff value of 8.9 μg/mL had a sensitivity of 93.3%; specificity of 83.3%; positive predictive value of 96.6%; negative predictive value of 71.4%; accuracy of 91.7%; and area under the curve of 0.904 for the prediction of endoscopic remission. Leucine-rich alpha-2 glycoprotein can be used in assessing endoscopic activity and is a reliable marker of endoscopic remission in CD patients. It can be an intermediate target in the treatment of CD.

This study aimed to determine the association between umbilical cord leucine-rich alpha-2 glycoprotein (LRG) and fetal infection and investigate the underlying mechanism of LRG elevation in fetuses. We retrospectively reviewed the medical records of patients who delivered at Osaka University Hospital between 2012 and 2017 and selected those with histologically confirmed chorioamnionitis (CAM), which is a common pregnancy complication that may cause neonatal infection. The participants were divided into two groups: CAM with fetal infection (CAM-f[+] group, n = 14) and CAM without fetal infection (CAM-f[−] group, n = 31). Fetal infection was defined by the histological evidence of funisitis. We also selected 50 cases without clinical signs of CAM to serve as the control. LRG concentrations in sera obtained from the umbilical cord were unaffected by gestational age at delivery, neonatal birth weight, nor the presence of noninfectious obstetric complications (all, p > 0.05). Meanwhile, the LRG levels (median, Interquartile range [IQR]) were significantly higher in the CAM-f(+) group (10.37 [5.21–13.7] μg/ml) than in the CAM-f(−) (3.61 [2.71–4.65] μg/ml) or control group (3.39 [2.81–3.93] μg/ml; p < 0.01). The area under the receiver operating characteristic (ROC) curve of LRG for recognizing fetal infection was 0.92 (optimal cutoff, 5.08 μg/ml; sensitivity, 86%; specificity, 88%). In a mouse CAM model established by lipopolysaccharide administration, the fetal LRG protein in sera and LRG mRNA in the liver were significantly higher than those in phosphate-buffered saline (PBS)-administered control mice (p < 0.01). In vitro experiments using a fetal liver-derived cell line (WRL68) showed that the expression of LRG mRNA was significantly increased after interleukin (IL)-6, IL-1β, and tumor necrosis factor- alpha (TNF-α) stimulation (p < 0.01); the induction was considerably stronger following IL-6 and TNF-α stimulation (p < 0.01). In conclusion, LRG is an effective biomarker of fetal infection, and fetal hepatocytes stimulated with inflammatory cytokines may be the primary source of LRG production in utero.

Leucine-rich alpha-2 glycoprotein (LRG) may be a novel serum biomarker for patients with inflammatory bowel disease. The association of LRG with the endoscopic activity and predictability of mucosal healing (MH) was determined and compared with those of C-reactive protein (CRP) and fecal markers (fecal immunochemical test [FIT] and fecal calprotectin [Fcal]) in 166 ulcerative colitis (UC) and 56 Crohn’s disease (CD) patients. In UC, LRG was correlated with the endoscopic activity and could predict MH, but the performance was not superior to that of fecal markers (areas under the curve [AUCs] for predicting MH: LRG: 0.61, CRP: 0.59, FIT: 0.75, and Fcal: 0.72). In CD, the performance of LRG was equivalent to that of CRP and Fcal (AUCs for predicting MH: LRG: 0.82, CRP: 0.82, FIT: 0.70, and Fcal: 0.88). LRG was able to discriminate patients with MH from those with endoscopic activity among UC and CD patients with normal CRP levels. LRG was associated with endoscopic activity and could predict MH in both UC and CD patients. It may be particularly useful in CD.