Increased cystatin C serum concentrations in patients with hepatic diseases of various severities

Cystatin C/albumin ratio for early diagnosis of esophageal varices in liver cirrhosis

The mortality rate related to variceal bleeding is high in patients with liver cirrhosis. Early detection and treatment of varices can reduce the risk of hemorrhage and thus decrease the mortality rate related to variceal bleeding. The study comprised 81 cirrhotic patients in training set, who were categorized into 2 groups: the patients with esophageal varices (EVs group) and the patients without esophageal varices (non-EVs group). The disparity in Cystatin C/albumin ratio (CAR) was assessed between these 2 groups. Subsequently, a regression model was constructed by generating a receiver operating characteristic (ROC) curve to calculate the area under the curve (AUC). Then an external validation was performed in 25 patients. Among patients with cirrhosis in training set, a statistically significant difference in CAR was observed between the EVs group and non-EVs group (P < .05). At the CAR cutoff value of 2.79*10-5, the AUC for diagnosing EVs were 0.666. Further, a multivariate logistic regression model was constructed, after adjusting the model, the AUC for EVs diagnosis were 0.855. And the external validation showed that the model could not be considered as a poor fit. CAR exhibits potential as an early detection marker for EVs in liver cirrhosis, and the regression model incorporating CAR demonstrates a strong capability for early EVs diagnosis.

Establishment of trimester-specific reference intervals of renal function tests and their predictive values in pregnant complications and perinatal outcomes: A population-based cohort study

Objectives

In this study, we aimed to establish the trimester-specific RIs of renal function tests (RFTs) in singleton pregnant women and investigate the associations between adverse perinatal outcomes and abnormal renal function laboratory results.

Methods

The results of RFTs and the associated medical records were retrieved from 16489 singleton pregnant women who underwent first- and third-trimester prenatal screening and gave a live birth at out institute between August 2018 and December 2019. The RFTs were performed on the automated immunochemistry platform ARCHITECT ci16200 (Abbott Laboratories Ltd, Abbott Park, Illinois, US) in the clinical laboratory of our institute. The nonparametric 2.5th-97.5th percentile intervals and the indirect Hoffmann methods were used to define the trimester-specific RIs. The associations between abnormal RFTs and adverse pregnancy outcomes was assessed statistically by logistic regression.

Results

There was no significant difference between the direct observational and the indirect Hoffmann methods in establishing RIs of RFTs. Compared with RFTs in the first trimester, the concentrations of serum BUN and Crea were slightly decreased (p < 0.001), and the serum UA and Cys C levels were significantly elevated in the third trimester (p < 0.001). In the logistic regression analysis, high concentrations of UA, Crea, and Cys C in late pregnancy were associated with an increased risk of postpartum hemorrhage. Meanwhile, early pregnancy UA was associated with a modestly increased risk of GDM, GH, and PE.

Conclusion

It is necessary to establish trimester-specific RIs for RFTs, in order to appropriately interpret laboratory results and to identify women with high risks of developing various adverse outcomes.

Serum cystatin C is an early renal dysfunction biomarker in patients with hepatitis C virus

Background

Hepatitis C virus (HCV) may induce extrahepatic manifestations as acute or chronic renal dysfunction. The aim was to evaluate the diagnostic role of some biomarkers as cystatin C, cryoglobulins, rheumatoid factor (RF), and complement C3 for extrahepatic renal affection in newly diagnosed patients with HCV infection.

Methods

Blood and urine were collected from randomized individuals screened for new HCV infection (n=400). The studied populations were divided into 3 groups: control group I: thirty healthy individuals not suffering from either liver or kidney diseases, group IIa: thirty HCV patients who have positive HCV antibody test but showed negative PCR test, and group IIb: thirty HCV patients who showed positive results for both HCV antibody and PCR tests.

Results

In HCV group IIb, levels of serum total bilirubin, AST and ALT, and urine albumin/creatinine ratio were increased whereas serum albumin and creatinine clearance were decreased versus other groups. However, the levels of blood urea nitrogen and serum creatinine were still within the normal range in all groups. In HCV group IIb, cystatin C, cryoglobulins, and RF levels were increased; meanwhile, serum creatinine/cystatin C ratio and complement 3 levels were decreased compared to the other groups. HCV-infected patients significantly had higher serum cystatin C (>1.24 mg/L, P<0.001) and lower creatinine/cystatin C ratio (<70.1μMol/mg, P=0.002), and cystatin C was significantly correlated with liver and kidney parameters.

Conclusion

High serum cystatin C and low creatinine/cystatin C ratio may be early indicators of mild renal dysfunction with normal serum levels of creatinine in HCV-infected individuals.

The ratio of creatinine and cystatin C estimated glomerular filtration rates as a surrogate marker in patients with hepatocellular carcinoma undergoing hepatic resection

BACKGROUND

The ratio of creatinine and cystatin C estimated glomerular filtration rates (eGFRcre/eGFRcys) is significantly positively correlated with sarcopenia. However, there are no published reports on the relationship between eGFRcre/eGFRcys and long-term prognosis in patients after hepatic resection for hepatocellular carcinoma (HCC).

METHODS

157 patients who had undergone curative hepatic resection for HCC were retrospectively reviewed. Cystatin C levels were measured in serum samples that had been frozen after collection at surgery. We aimed to investigate the significance of cystatin C in prognostic value following hepatic resection for HCC.

RESULTS

The best cut-off eGFRcre/eGFRcys value for overall survival after hepatic resection for HCC was 1.0025. High eGFRcre/eGFRcys was significantly associated with poor liver function, low skeletal muscle mass, large tumor size, large ascitic volume, worse overall and recurrence-free survival. The eGFRcre/eGFRcys was significantly related to severe recurrence patterns (multiple liver recurrences, distant metastasis).

CONCLUSIONS

Preoperative eGFRcre/eGFRcys can predict overall and recurrence-free survival in HCC patients undergoing hepatic resection. The eGFRcre/eGFRcys is a simple and reliable surrogate marker that indicate for eligibility for hepatic resection for HCC.

Cystatin C relates to metabolism in healthy, pubertal adolescents

INTRODUCTION

The cystatin C (CysC) serum level is a marker of glomerular filtration rate and depends on age, gender, and pubertal stage. We hypothesize that CysC might overall reflect energy homeostasis and be regulated by components of the endocrine system and metabolites in pubertal adolescents.

METHODS

Serum CysC levels and further possible effector parameters in 5355 fasting, morning venous blood samples from 2035 healthy participants of the LIFE Child cohort study (age 8 to 18 years) were analyzed. Recruitment started in 2011, with probands followed up once a year. Linear univariate and stepwise multivariate regression analyses were performed.

RESULTS

Annual growth rate, serum levels of thyroid hormones, parathyroid hormone, insulin-like growth factor 1, hemoglobin A1c (HbA1c), uric acid, and alkaline phosphatase show relevant and significant associations with CysC serum concentrations (p <0.001). Furthermore, male probands' CysC correlated with the body mass index and testosterone among other sexual hormones. Multivariate analyses revealed that uric acid and HbA1c are associated variables of CysC independent from gender (p <0.001). In males, alkaline phosphatase (p <0.001) is additionally significantly associated with CysC. Thyroid hormones show significant correlations only in multivariate analyses in females (p <0.001).

CONCLUSIONS

The described associations strongly suggest an impact of children's metabolism on CysC serum levels. These alterations need to be considered in kidney diagnostics using CysC in adolescents. Additionally, further studies are needed on CysC in children.

Rat Model Investigation on the Role of Biomarkers in Hepatic Ischemia-Reperfusion Injury

OBJECTIVES

Liver function is affected by ischemiareperfusion. Ischemia-reperfusion injury to the liver often follows hepatobiliary surgery. Here, we investigated biomarkers of liver ischemia-reperfusion injury using an animal model.

MATERIALS AND METHODS

For this study, 24 male Sprague Dawley rats (146-188 g) were divided into 4 groups: group A was the control group, group B was the partial hepatic ischemia-reperfusion group, group C was the total hepatic ischemia-reperfusion group, and group D was the intermittent total hepatic ischemiareperfusion group. Laboratory liver function levels were measured before ischemia, after ischemia, and after reperfusion. We used liver and renal biopsies for histopathological examination at the end of the study.

RESULTS

After clamping and reperfusion, alanine aminotransferase and cystatin C levels in groups B, C, and D were significantly higher than levels in group A. In group B, after clamping, neutrophil gelatinaseassociated lipocalin levels were higher than in groups A and D, with significantly higher level than in group D after reperfusion. Neutrophil gelatinase-associated lipocalin levels decreased significantly in groups B, C, and D after reperfusion. There was significantly greater hepatic damage in groups B, C, and D compared with group A but no significant differences in renal injury scores among the groups. There was a significant positive correlation between hepatic damage and renal injury. With regard to histopathological examination versus laboratory results, a statistically significant positive correlation was shown between grade of hepatic damage and serum alanine aminotransferase and cystatin C levels. Similarly, there was a positive correlation between renal damage score and alanine aminotransferase level.

CONCLUSIONS

In our animal model, alanine amino - transferase and cystatin C levels tended to increase with ischemia-reperfusion injury levels but neutrophil gelatinase-associated lipocalin decreased during reperfusion. In liver ischemia, we suggest that neutrophil gelatinase-associated lipocalin may be an important biomarker for distinguishing the reperfusion phase.

Chronic kidney disease and the risk of incident hearing loss

OBJECTIVES

There is a strikingly high prevalence of sensorineural hearing loss among patients with chronic kidney disease, with estimates ranging from 36% to 77%; however, longitudinal data are limited. We assessed whether lower baseline estimated glomerular filtration rate calculated using creatinine (eGFR_Cr ), as well as decline in eGFR_Cr over time, were associated with incident hearing loss.

METHODS

Serum creatinine was measured in 1,843 individuals aged 48 to 80 years without hearing loss at the start of the Epidemiology of Hearing Loss Study in 1993. Follow-up creatinine assessments were conducted at 5 (n = 1,526) and 10 (n = 1,095) years. Hearing tests were conducted at baseline and at 5-, 10-, and 15-year follow-up visits. The risk of hearing loss was assessed as a function of baseline eGFR_Cr as well as a function of a 20% decline in eGFR_Cr between baseline and 5 years and between 5 and 10 years. Cox proportional hazards regression was used to examine the risk of incident speech-frequency hearing loss, defined as pure tone average (PTA) > 25 decibels hearing loss for thresholds at 0.5, 1, 2, and 4 kHz (PTA_0.5,1,2,4 ) in either ear.

RESULTS

During 15,676 person-years of follow up, there were 802 cases of incident hearing loss. There was no statistically significant association between lower baseline eGFR_Cr and risk of incident hearing loss. Decline in eGFR_Cr was also not associated with incident hearing loss at speech frequencies.

CONCLUSION

Overall, there was no significant association between eGFR_Cr or decline in eGFR_Cr using the serum creatinine-based equation and risk of incident hearing loss.

LEVEL OF EVIDENCE

2 Laryngoscope, 130:E213-E219, 2020.

Estimation of renal function in patients with liver cirrhosis: Impact of muscle mass and sex

BACKGROUND & AIMS

Accurate evaluation of renal function in patients with liver cirrhosis is critical for clinical management. However, there are still discrepancies between the measured glomerular filtration rate (mGFR) and creatinine-based estimated GFR (eGFR). In this study, we compared the performance of 2 common eGFR measurements with mGFR and evaluated the impact of low muscle mass on overestimation of renal function in patients with cirrhosis.

METHODS

This study included 779 consecutive cirrhotic patients who underwent ⁵¹Cr-ethylenediamine tetra acetic acid (EDTA) (as a mGFR) and abdominal computed tomography (CT). The eGFR was calculated using creatinine or cystatin C. Muscle mass was assessed in terms of the total skeletal muscle at L3 level using CT.

RESULTS

Modification of diet in renal disease (MDRD)-eGFR was overestimated in 47% of patients. A multivariate analysis showed that female sex (adjusted odds ratio [aOR] 4.91), Child B and C vs. A (aOR 1.69 and 1.84) and skeletal muscle mass (aOR 0.89) were independent risk factors associated with overestimation. Interestingly, the effect of skeletal muscle mass on overestimation varied based on sex. Decreased muscle mass significantly enhanced the risk of overestimation of MDRD-eGFR in male patients, but not in female patients. Cystatin C-based eGFR showed a better correlation with mGFR than MDRD-eGFR; it was also better at predicting overall survival and the incidence of acute kidney injury than MDRD-eGFR.

CONCLUSIONS

The risk factors associated with overestimation included female sex, impaired liver function, and decreased muscle mass in males. In particular, eGFR in male patients with sarcopenia should be carefully interpreted. Creatinine-based eGFR was overestimated more often than cystatin C-based eGFR, with overestimation of eGFR closely related to poor prognostic performance.

LAY SUMMARY

Overestimation of renal function frequently occurs in patients with liver cirrhosis when using serum creatinine. Decreased muscle mass has a great impact on overestimation of kidney function especially in male patients with cirrhosis. Compared with creatinine, cystatin C was more closely correlated with measured glomerular filtration rate and had a higher predictive ability for renal complications and survival than creatinine.

Cystatin C as a novel predictor of preterm labor in severe preeclampsia

Background

The most common cause of acute kidney injury (AKI) in pregnancy is preeclampsia. Serum cystatin C (CysC) is a potential biomarker of early kidney damage as its levels are not disturbed by volume status changes in pregnancy, and serum CysC levels could serve as a replacement for conventionally used creatinine. In this study, we investigated the serum levels of CysC in severe preeclampsia cases and the associations between CysC levels and poor obstetric outcomes.

Methods

Our cohort included severe preeclampsia patients with a normal serum creatinine level. Creatinine was measured to calculate estimated glomerular filtration rate (eGFR) based on the Cockcroft and Gault, Modification of Diet in Renal Disease Study (MDRD), and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations, while CysC was measured to calculated eGFR based on a CysC-based equation. We then evaluated the correlations between serum CysC level, eGFR, and obstetric outcomes.

Results

Twenty-six patients were evaluated of which 38.5% delivered preterm and 30.8% had low-birth weight babies. Unlike creatinine-based eGFR and CysC-based eGFR, serum CysC demonstrate significant negative correlation with gestational age. Receiver operating characteristic curve analysis indicated that serum CysC is a potential biomarker of preterm delivery with a cut-off serum level of 1.48 mg/L with 80% sensitivity and 75% specificity.

Conclusion

GFR estimation using CysC is likely to be inaccurate in pregnancy. However, we found a significant correlation between preterm delivery and serum CysC level. Our results suggest that serum CysC level has the potential to predict preterm delivery in severe preeclampsia patients.

The Clinical Importance of Cystatin C and Hepatic Artery Resistive Index in Liver Cirrhosis

Background: Data suggest cystatin C (CysC) levels and hepatic artery resistive index (HARI) correspond to the progression of chronic liver disease. We aimed to evaluate the clinical significance of these parameters in assessment of fibrosis in patients with liver cirrhosis. Methods: The cross-sectional study included 63 patients with liver cirrhosis. A control group consisted of 30 age- and gender-matched healthy persons. Results: We confirmed significantly higher values of CysC in patients with cirrhosis compared to control group (p = 0.036). Average value of HARI in the examined group was increased (0.72 ± 0.06) and there was the statistically significant difference compared to controls (0.66 ± 0.03) (p < 0.001). We found statistically significant correlation between HARI and CysC in the study group. Analyzing the possibility of distinguishing healthy subjects from patients with fibrosis, we have found that the area under the curve is far greater in the HARI index than CysC. Comparison of CysC among Child–Pugh stages and correlation with a model for end-stage liver disease (MELD) score showed statistically significant results. Conclusion: We confirmed HARI is a more accurate parameter than CysC in discriminating healthy subjects from patients with fibrosis, while CysC could be a better indicator of the stage of liver cirrhosis.

Elevated cystatin C: is it a reflection for kidney or liver impairment in hepatic children?

Aim of the study

To assess if elevated serum cystatin C (Cyst-C) is an indicator for renal or hepatic dysfunction in presence of liver fibrosis.

Material and methods

Data of 50 children with chronic liver diseases (CLDs), out of which 25 were without renal impairment, and 25 with renal impairment were analyzed. Twenty healthy children served as a healthy control group. Routine investigations, creatinine clearance, hepatitis viral markers, abdominal ultrasonography, and liver biopsy were performed for patients with CLDs. Measurement of serum Cyst-C concentration by particle induced immunonephelometry were completed for both patients and control group.

Results

Results showed that serum Cyst-C is not correlated with the degree of hepatic impairment (p > 0.05). Cyst-C levels were significantly higher in patients with renal impairment (3.66 ± 0.85) than those without (0.71 ± 0.12), and healthy control group (0.63 ± 0.85). Cystatin-C showed significant elevation in patients with severe fibrosis with renal impairment (3.66 ± 0.85) than those without (0.76 ± 0.04) (p < 0.0001). Cyst-C at cutoff levels of 1.65 mg/l showed 100% accuracy in discrimination between those with and those without renal impairment. Cyst-C > 2.34 mg/l predicting GFR < 40 ml/min with accuracy of 90%. Cyst-C > 2.73 mg/l predicting GFR < 20 ml/min with accuracy of 81.5%.

Conclusions

Serum Cyst-C is a promising marker to estimate renal impairment in children with CLDs. Further studies are needed to estimate the accuracy of serum Cyst-C for early detection of renal impairment and close monitoring of the hepatic children.

Comparison of Risk Prediction With the CKD-EPI and MDRD Equations in Non-ST-Segment Elevation Acute Coronary Syndrome

BACKGROUND

Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations estimate glomerular filtration rate (GFR) more accurately than the Modification of Diet in Renal Disease (MDRD) equation.

HYPOTHESIS

New CKD-EPI equations improve risk stratification in patients with non-ST-segment elevation acute coronary syndrome (NSTE-ACS) and provide complementary information to the Global Registry of Acute Coronary Events (GRACE) risk score.

METHODS

We studied 350 subjects (mean age, 68 ± 12 years; 70% male) with NSTE-ACS. Estimated GFR was calculated using the MDRD and new CKD-EPI equations based on serum creatinine (SCr) and/or cystatin C (CysC) concentrations obtained within 48 hours of hospital admission. The primary endpoint was all-cause death during follow-up.

RESULTS

Over the study period (median, 648 days [interquartile range, 236-1042 days]), 31 patients died (0.05% events per person-year). Decedents had poorer renal-function parameters (P < 0.001). Both CysC-based CKD-EPI equations had the highest areas under the receiver operating characteristic curve for the prediction of all-cause mortality. After multivariate adjustment, only CysC-based CKD-EPI equations were independent predictors of all-cause mortality (CKD-EPISCr - CysC , per mL/min/1.73 m(2) : hazard ratio: 0.975, 95% confidence interval: 0.956-0.994, P = 0.009; CKD-EPICysC , per mL/min/1.73 m(2) : hazard ratio: 0.976, 95% confidence interval: 0.959-0.993, P = 0.005). Reclassification analyses showed that only CysC-based CKD-EPI equations improved predictive accuracy of the GRACE risk score.

CONCLUSIONS

In patients with NSTE-ACS, CysC-based CKD-EPI equations improved clinical risk stratification for mortality and added complementary prognostic information to the GRACE risk score.

Kidney Failure and Liver Allocation: Current Practices and Potential Improvements

In February 2002, the United Network for Organ Sharing implemented a system for prioritizing candidates for liver transplantation that was based on the risk of 90-day mortality as determined by the Model for End-Stage Liver Disease (MELD) score. As the MELD score is driven in part by serum creatinine as a marker of kidney function, the prevalence of kidney dysfunction and failure in patients with end-stage liver disease at the time of listing and at transplantation has steadily risen. In this review, we discuss current practices in liver transplantation in patients with kidney dysfunction focusing briefly on the decision to perform simultaneous liver-kidney transplantation. We then discuss pitfalls to the current practices of liver transplantation in patients with kidney dysfunction. We conclude by discussing potential improvements to current practices including the use of the MELD-Na score, alternatives to creatinine and creatinine-based equation for estimating kidney function, and the use of intraoperative kidney replacement therapy during liver transplantation.

Serum cathepsin B to cystatin C ratio as a potential marker for the diagnosis of cholangiocarcinoma

Cholangiocarcinoma (CCA) is a cancer of the bile duct epithelial cells. The highest incidence rate of CCA with a poor prognosis and poor response to chemotherapy is found in Southeast Asian countries, especially in northeastern Thailand and Lao PDR. Cathepsin B is a lysosomal cysteine protease which is regulated by cysteine proteinase inhibitors such as cystatin C. Elevation of cathepsin B levels in biological fluid has been observed in patients with inflammatory diseases and many cancers. We aimed to investigate the serum cathepsin B and cystatin C levels of CCA patients to evaluate the feasibility of using cathepsin B and cystatin C as markers for the diagnosis of CCA. Fifty-six sera from CCA patients, 17 with benign biliary diseases (BBD) and 13 from controls were collected and the cathepsin B and cystatin C levels were determined. In addition, cathepsin B expression was investigated immunohistochemically for 9 matched-pairs of cancerous and adjacent tissues of CCA patients. Serum cathepsin B, but not cystatin C, was significantly higher in CCA and BBD patient groups compared to that in the control group. Consistently, all cancerous tissues strongly expressed cathepsin B while adjacent tissues were negative in 7 out of 9 cases. In contrast, serum cystatin C levels were comparable between CCA and control groups, although serum cystatin C levels in the BBD group was higher than that in the control or CCA groups. When the serum cathepsin B to cystatin C ratio was calculated, that of the CCA group was significantly higher than that of the control group, and, although statistically not significant, the ratio of CCA group showed a trend to be higher than that of the BBD group. Thus, the cathepsin B to cystatin C ratio might be used as an alternative marker for aiding diagnosis of CCA.

LC-MS/MS-based serum proteomics for identification of candidate biomarkers for hepatocellular carcinoma

Associating changes in protein levels with the onset of cancer has been widely investigated to identify clinically relevant diagnostic biomarkers. In the present study, we analyzed sera from 205 patients recruited in the United States and Egypt for biomarker discovery using label-free proteomic analysis by LC-MS/MS. We performed untargeted proteomic analysis of sera to identify candidate proteins with statistically significant differences between hepatocellular carcinoma (HCC) and patients with liver cirrhosis. We further evaluated the significance of 101 proteins in sera from the same 205 patients through targeted quantitation by MRM on a triple quadrupole mass spectrometer. This led to the identification of 21 candidate protein biomarkers that were significantly altered in both the United States and Egyptian cohorts. Among the 21 candidates, ten were previously reported as HCC-associated proteins (eight exhibiting consistent trends with our observation), whereas 11 are new candidates discovered by this study. Pathway analysis based on the significant proteins reveals upregulation of the complement and coagulation cascades pathway and downregulation of the antigen processing and presentation pathway in HCC cases versus patients with liver cirrhosis. The results of this study demonstrate the power of combining untargeted and targeted quantitation methods for a comprehensive serum proteomic analysis, to evaluate changes in protein levels and discover novel diagnostic biomarkers. All MS data have been deposited in the ProteomeXchange with identifier PXD001171 (http://proteomecentral.proteomexchange.org/dataset/PXD001171).

Estimating glomerular filtration rate in acute coronary syndromes: Different equations, different mortality risk prediction

AIMS

Renal dysfunction is a powerful predictor of adverse outcomes in patients hospitalized for acute coronary syndrome. Three new glomerular filtration rate (GFR) estimating equations recently emerged, based on serum creatinine (CKD-EPIcreat), serum cystatin C (CKD-EPIcyst) or a combination of both (CKD-EPIcreat/cyst), and they are currently recommended to confirm the presence of renal dysfunction. Our aim was to analyse the predictive value of these new estimated GFR (eGFR) equations regarding mid-term mortality in patients with acute coronary syndrome, and compare them with the traditional Modification of Diet in Renal Disease (MDRD-4) formula.

METHODS AND RESULTS

801 patients admitted for acute coronary syndrome (age 67.3±13.3 years, 68.5% male) and followed for 23.6±9.8 months were included. For each equation, patient risk stratification was performed based on eGFR values: high-risk group (eGFR<60ml/min per 1.73m(2)) and low-risk group (eGFR⩾60ml/min per 1.73m(2)). The predictive performances of these equations were compared using area under each receiver operating characteristic curves (AUCs). Overall risk stratification improvement was assessed by the net reclassification improvement index. The incidence of the primary endpoint was 18.1%. The CKD-EPIcyst equation had the highest overall discriminate performance regarding mid-term mortality (AUC 0.782±0.20) and outperformed all other equations (ρ<0.001 in all comparisons). When compared with the MDRD-4 formula, the CKD-EPIcyst equation accurately reclassified a significant percentage of patients into more appropriate risk categories (net reclassification improvement index of 11.9% (p=0.003)). The CKD-EPIcyst equation added prognostic power to the Global Registry of Acute Coronary Events (GRACE) score in the prediction of mid-term mortality.

CONCLUSION

The CKD-EPIcyst equation provides a novel and improved method for assessing the mid-term mortality risk in patients admitted for acute coronary syndrome, outperforming the most widely used formula (MDRD-4), and improving the predictive value of the GRACE score. These results reinforce the added value of cystatin C as a risk marker in these patients.

[Usefulness of cystatin C as a prognostic marker in venous thromboembolism]

BACKGROUND AND OBJECTIVE

Cystatin C (cysC) is a prognostic marker in patients with hypertension, coronary heart disease and heart failure. The aim of this study was to determine the prognostic value of cysC levels obtained at the time of diagnosis in patients with venous thromboembolism (VTE).

MATERIAL AND METHOD

Retrospective study of a cohort of 226 consecutive patients with VTE, followed for 6 months. Serum samples were obtained for the determination of cysC, creatinine, and the N-terminal fraction of the brain natriuretic peptide (NT-proBNP) at the time of diagnosis.

RESULTS

The highest discriminating power value of dying at 6 months for cysC was 1,175mg/dl (sensitivity 76%, specificity 65%, positive predictive value 26%, negative predictive value 94%). Above the cut-off, 17/48 patients died, versus 9/152 that had lower levels (odds ratio: 5.98, 95% confidence interval [95% CI]: 2.50-14.29, P<.001). The adjusted hazard ratio in a multivariate model was 3.76 (95% CI 1.46-9.66). The accuracy of this parameter was similar to that for creatinine (1.24mg/dl) but lower than the NT-proBNP (435pg/ml). Patients who exceeded the limit values of cysC and NT-proBNP together had no greater risk of death than those above NT-proBNP only (odds ratio: 9.43, 95% CI 3.90-22.81, P<.001). There was no value, which was significantly associated with bleeding episodes or recurrent thromboembolism.

CONCLUSION

CysC concentration at the time of diagnosis in VTE patients has prognostic value, which is similar to that of serum creatinine and lower than that of NT-proBNP.

Creatinine- versus cystatine C-based equations in assessing the renal function of candidates for liver transplantation with cirrhosis

Renal dysfunction is frequent in liver cirrhosis and is a strong prognostic predictor of orthotopic liver transplantation (OLT) outcome. Therefore, an accurate evaluation of the glomerular filtration rate (GFR) is crucial in pre-OLT patients. However, in these patients plasma creatinine (Pcr) is inaccurate and the place of serum cystatine C (CystC) is still debated. New GFR-predicting equations, based on standardized assays of Pcr and/or CystC, have been recently recommended in the general population but their performance in cirrhosis patients has been rarely studied. We evaluated the performance of the recently published Chronic Kidney Disease Epidemiology Collaboration equations (CKD-EPI-Pcr, CKD-EPI-CystC, and CKD-EPI-Pcr-CystC) and the more classical ones (4- and 6-variable MDRD and Hoek formulas) in cirrhosis patients referred for renal evaluation before OLT. Inulin clearance was performed in 202 consecutive patients together with the determination of Pcr and CystC with assays traceable to primary reference materials. The performance of the GFR-predicting equations was evaluated according to ascites severity (no, moderate, or refractory) and to hepatic and renal dysfunctions (MELD score  ≤ or >15 and KDOQI stages, respectively). In the whole population, CystC-based equations showed a better performance than Pcr-based ones (lower bias and higher 10% and 30% accuracies). CKD-EPI-CystC equation showed the best performance whatever the ascites severity and in presence of a significant renal dysfunction (GFR <60 mL/min/1.73 m(2)).

CONCLUSION

Pcr-based GFR predicting equations are not reliable in pre-OLT patients even when an IDMS-traceable enzymatic Pcr assay is used. Whenever a CystC-assay traceable to primary reference materials is performed and when a true measurement of GFR is not possible, CystC-based equations, especially CKD-EPI-CystC, may be recommended to evaluate renal function and for KDOQI staging.

Human cystatin C: a new biomarker of idiopathic pulmonary fibrosis?

PURPOSE

Human idiopathic pulmonary fibrosis (IPF) is a progressive interstitial lung disorder with a poor prognosis. The identification of a new and specific biomarker in bronchoalveolar lavage fluids (BALFs) may assist in the diagnosis of the disease.

EXPERIMENTAL DESIGN

Characterization of cysteine Cats and their endogenous inhibitor, cystatin C, was conducted by immunochemical analysis and measurement of endopeptidase activity of control (n = 11) and IPF (n = 25) BALFs (normalized conditions, 20 μg protein/assay).

RESULTS

Cathepsin (Cat) B was detected as proform and mature enzyme for both control and IPF samples, while Cats K, L, and S were found as zymogens with a strengthened staining in IPF BALFs. The overall endopeptidase activity related mainly to Cat B and did not vary significantly between control and IPF samples. Conversely a significant increase of immunoreactive cystatin C was measured in BALFs for each of three IPF grades.

CONCLUSIONS AND CLINICAL RELEVANCE

An excessive deposition of extracellular matrix proteins is the hallmark of fibrotic disorders. Cats are potent collagenases and might be essential for lung homeostasis. Taken together, increase of cystatin C in IPF BALFs may reflect abnormal regulation of proteolytic activity of Cats in lung, which in turn can promote the development of fibrosis.

Performance of cystatin C-based equations in a pediatric cohort at high risk of kidney injury

BACKGROUND

Limited data exist on the performance of cystatin C-based glomerular filtration rate (GFR) equations in pediatric transplant recipients and other high-risk patients. The aim of our study was therefore to evaluate the performance of current cystatin C-based equations in this population.

METHODS

This was a retrospective, cross-sectional study of 141 consecutive patients (58 % post-transplant) who received a nuclear medicine GFR (NucGFR) examination using (99m)Tc- diethylenetriaminepentaacetic acid at our institution. Subjects included children receiving liver, kidney or hematopoietic stem cell transplants and patients with oncologic or urologic disease. GFR estimates using published GFR estimating equations, including those based on cystatin C (Filler, Zappitelli, Larsson, Hoek, Rule and Le Bricon equations, respectively) and on both cystatin C and creatinine (Zappitelli, Bouvet and Schwartz equations, respectively), were evaluated and compared to the NucGFR measurement using Bland-Altman analysis.

RESULTS

The mean NucGFR was 95 (interquartile range 76-111) ml/min/1.73 m(2). Of the cystatin C-based equations, the Rule, Hoek, Zappitelli and Schwartz (2009 CKiD equation) formulas provided the closest agreement to the NucGFR estimate. All other formulas overestimated the GFR in our cohort.

CONCLUSION

Cystatin C-based GFR formulas can provide an accurate estimation of NucGFR in a pediatric population with a high proportion of transplant recipients and oncology patients.

Unveiling New Molecular Factors Useful for Detection of Pelvic Inflammatory Disease due to Chlamydia trachomatis Infection

Background. Untreated Chlamydia trachomatis infections in women can result in disease sequelae such as pelvic inflammatory disease (PID), ultimately culminating in tubal occlusion and infertility. While nucleic acid amplification tests can effectively diagnose uncomplicated lower genital tract infections, they are not suitable for diagnosing upper genital tract pathological sequelae. Objective. The purpose of this paper was to provide a comprehensive review of new molecular factors associated with the diagnosis and prognosis of PID. Material and Methods. The literature was searched using the key words “Chlamydia trachomatis infections,” “pelvic inflammatory disease,” and “molecular factors” in the PubMed database. Relevant articles published between 1996 and 2012 were evaluated. Conclusions. The use of new molecular factors could potentially facilitate earlier diagnosis and prognosis in women with PID due to C. trachomatis infection.

Serum cystatin C correlates negatively with viral load in treatment-naïve children with chronic hepatitis C

OBJECTIVES

Hepatitis C virus (HCV) infection is a serious health problem that causes chronic infection in up to 85% of cases. HCV nonstructural (NS) cysteine protease, NS2/3, is required for viral replication in vivo. Cystatin C is a naturally occurring cysteine protease inhibitor in human cells. We aimed to investigate the relation between serum levels of cystatin C and HCV viremia in treatment-naïve children with chronic hepatitis C.

METHODS

Serum cystatin C levels were measured in 27 children with chronic hepatitis C and determined their relation with liver functions, histopathological parameters, and hepatitis C viral load. Serum cystatin C was compared with that of 25 age- and sex-matched healthy controls.

RESULTS

Cystatin C was significantly higher in patients than in controls (1.4 ± 0.47 vs 0.99 ± 0.49; P = 0.006), and in those with low viremia than in those with moderate viremia (1.55 ± 0.41 vs 0.99 ± 0.43; P = 0.013). Cystatin C was not correlated with histopathological findings in liver biopsy (P > 0.05 for all). In addition, there was no significant difference of cystatin C levels in patients with normal versus those with elevated transaminases (P > 0.05). Of importance, cystatin C correlated negatively with viral load (P < 0.0001).

CONCLUSIONS

Cystatin C levels correlated negatively with HCV viremia. This finding may reflect an inhibitory effect of cystatin C on HCV replication through inhibiting its NS2/3 and tempting for further studies for cystatin C as a possible adjuvant therapy for HCV infection.

Significant elevation of plasma cathepsin B and cystatin C in patients with community-acquired pneumonia

BACKGROUND

We identified the relationship between plasma level changes of cathepsin B and cystatin C before and after antibiotic treatment in hospitalized adult patients with community-acquired pneumonia (CAP).

METHODS

We collected blood specimens from 61 adult patients with CAP before and after antibiotic treatment and from 60 healthy controls and measured the plasma concentrations of cathepsin B and cystatin C expression using the enzyme-linked immunosorbent assay (ELISA). The APACHE II, CURB-65, and Pneumonia Severity Index (PSI) scores were determined to assess CAP severity in patients upon initial hospitalization.

RESULTS

The results showed a decline in the number of WBCs and neutrophils, with decreases in the concentrations of CRP, cathepsin B, cystatin C, and the cathepsin B/cystatin C ratio being observed after antibiotic treatment. The plasma concentration of cathepsin B correlated with severity of CAP with the PSI score (r=0.290, p=0.025) and the CURB-65 score (r=0.258, p=0.047), respectively. The plasma concentration of cystatin C correlated with the APACHE II score (r=0.523, p<0.001), severity of CAP in the PSI score (r=0.721, p<0.001) and the CURB-65 score (r=0.609, p<0.001), respectively.

CONCLUSIONS

Cathepsin B and cystatin C may play a role in the diagnosis and clinical assessment of the severity of CAP, which could potentially guide the development of treatment strategies.

Comparison of cystatin C and creatinine-based glomerular filtration rate formulas with 51Cr-EDTA clearance in patients with cirrhosis

BACKGROUND AND OBJECTIVES

Renal function is an important predictor of survival in cirrhosis and liver transplantation. GFR estimates using serum cystatin C (CysC) are proposed as better predictors of renal function than ones on the basis of serum creatinine (Cr). Our aims were: (1) evaluate correlations between serum CysC and different methods of creatinine measurements; (2) compare CysC and Cr GFR formulas with (51)Cr-EDTA; and (3) evaluate liver-related parameters potentially influencing GFR.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

254 blood samples in 65 patients with cirrhosis correlating CysC with four Cr methods were used; another 74 patients comparing (51)Cr-EDTA GFR to Modification of Diet in Renal Disease and Larsson and Hoek formulas for CysC were also included. Agreement was assessed using Bland-Altman plots and concordance correlation coefficients. Multivariate linear regression analysis was used for GFR predictors.

RESULTS

Serum CysC correlated modestly with O'Leary modified Jaffe, compensated kinetic Jaffe, enzymatic creatinine, and standard kinetic Jaffe 0.72/0.71/0.72/0.72 (all P < 0.001). Bland-Altman agreement with (51)Cr-EDTA GFR was poor; the best agreement was Modification of Diet in Renal Disease (concordance 0.61; 95% CI, 0.47 to 0.71); the worst agreement was the Hoek formula (concordance 0.46; 95% CI, 0.27 to 0.61). A new GFR formula including the Child-Pugh score improved the accuracy of Cr GFR formulas compared with (51)Cr-EDTA GFR.

CONCLUSIONS

Estimated GFR in cirrhosis is not better with CysC formulas compared with creatinine ones: specific formulas may be necessary.

Estimation of glomerular filtration rate in liver-transplanted children: comparison of simplified procedures using 51Cr-EDTA and endogenous markers with Sapirstein's method as a reference standard

This study evaluated simple procedures for GFR determination in 48 liver-transplanted children. After injection of (51)Cr-EDTA, blood samples were obtained up to four h, and activity retention in the body was measured for 60 min with scintillation probes. As a reference, GFR was calculated according to Sapirstein. Simplified calculations were performed according to Brochner-Mortensen, Russel, Devaux and Oberhausen. Additionally, GFR was determined using plasma creatinine and cystatin C according to Schwartz and Filler, respectively. The reference revealed mildly reduced GFR (62 +/- 20 mL/min/1.73 m(2)). Russel's method provided the highest degree of correlation (r(2) = 0.95), the smallest bias in GFR determination (-2%), and only one false exclusion plus one false diagnosis of chronic kidney disease. Oberhausen's method with blood sampling at one h post-injection performed slightly worse (r(2) = 0.67, bias: 3%). All other methods resulted in significantly different GFR estimates compared to the reference. Nevertheless, notably, the second narrowest 95% limits of agreement (-31% to 45%) was observed using cystatin C. In conclusion, this data implies to prefer Russel's method as a simplified procedure, and if patients cannot be available long enough (four h) for measurements, Oberhausen's method instead. If radiotracer methods are not available at all or for screening GFR, cystatin C appears to be the procedure of choice.

The evaluation of renal function and disease in patients with cirrhosis

The MELD score has shown that, besides markers of liver function, serum creatinine has a strong prognostic value in cirrhosis. However, even though creatinine has a good prognostic value, it is an inaccurate marker of renal function in cirrhosis. Creatinine and creatinine-based equations tend to overestimate glomerular filtration rate (GFR), and creatinine clearance from timed urine collection also overestimates GFR. Hence, clearance of exogenous markers such as iohexol remains the only reliable method for assessing precisely GFR in cirrhosis. Whereas these investigations are limited by their costs and complexity, and they can hardly be repeated at short intervals, serum cystatin C could be an alternative, although it needs further validation. Accurate markers and/or specific equations are therefore still needed to assess GFR in cirrhotic patients. Pre-renal failure and hepatorenal syndrome (HRS) are the main causes of acute renal failure in cirrhosis. Both result from decreased renal blood flow and both can result in acute tubular necrosis. HRS is not always fully reversible with liver transplantation possibly due to underlying chronic kidney damage. A number of cirrhotic patients with acute renal failure may also have chronic kidney damage ("acute-on-chronic renal failure"); furthermore, cirrhotic patients frequently have co-morbidities such as diabetes that may result in chronic impairment in renal function. Since conventional urinary markers are biased in cirrhosis, a biopsy is the only way to document and quantify renal lesions; moreover, transvenous route should be preferred to percutaneous route. In candidates for transplantation, attention should therefore be focused on vascular lesions which may represent a risk factor for nephrotoxicities induced by calcineurin-inhibitors.

Role of N-terminal pro-brain natriuretic peptide and cystatin C to estimate renal function in patients with and without heart failure

Blood cystatin C has increasingly been used as an endogenous marker for estimating glomerular filtration rate (GFR) and evaluating prognosis in patients with acute or chronic heart failure. The goal of the study was to investigate the impact of heart failure on the determination of renal function based on cystatin C or creatinine in nonacute cardiac patients. A total of 880 consecutive and clinically stable patients with heart disease were prospectively evaluated. Serum N-terminal pro-brain natriuretic peptide (NT-pro-BNP) showed a stronger correlation with cystatin C (r = 0.60, p <0.001) compared with creatinine (r = 0.46, p <0.001). Multivariate analysis identified estimated GFR according to the MDRD Study formula (p <0.001), serum NT-pro-BNP (p <0.001), use of immunosuppressive agents (p <0.001), and allopurinol treatment (p <0.001) as the strongest independent predictors of serum cystatin C. Parallel measurement of creatinine clearance using timed urine collection in a subgroup of 160 patients showed that estimated GFR according to cystatin C was almost identical to measured creatinine clearance independent of NT-proBNP. Conversely, creatinine-based calculation using the MDRD Study formula underestimated GFR in patients from the low (12 to 238 pg/ml) and medium (241 to 990 pg/ml) NT-pro-BNP tertiles. In conclusion, in patients without severe heart failure, indicated by low serum NT-pro-BNP, estimation of GFR using creatinine-based formulas underestimated renal function. The known prognostic impact of cystatin C in cardiac patients might result from a strong correlation with NT-pro-BNP, as well as its superior ability to predict renal function in patients with and without heart failure.

Correlation of serum ribavirin concentration with pretreatment renal function estimates in patients with chronic hepatitis C receiving combination antiviral therapy with peginterferon and ribavirin

Serum ribavirin concentration is an important factor in antiviral therapy in combination with peginterferon (PEG-IFN) and ribavirin for patients with chronic hepatitis C in terms of both beneficial and adverse effects. We evaluated whether the serum ribavirin concentration can be predicted on the basis of renal function estimates. Serum creatinine and cystatin C concentrations were measured at the start of treatment in a total of 148 patients with chronic hepatitis C who underwent combination PEG-IFN and ribavirin therapy. Creatinine clearance (CrCl) and total clearance of ribavirin (CL/F) were calculated on the basis of the serum creatinine level. The glomerular filtration rate was calculated with two different formulae on the basis of the serum cystatin C level. These values were compared with serum ribavirin concentrations 4 weeks after the start of therapy. The cystatin C level increased with the progression of liver fibrosis, whereas the creatinine level was constant regardless of the degree of liver fibrosis. Significant correlation was not observed between the serum ribavirin concentration and serum creatinine level, cystatin C level, or calculated renal function estimates. However, significant correlation was found between the serum ribavirin concentration and CrCl and CL/F in patients who were given ribavirin >800 mg/day. Overall, renal function estimates do not correlate with the serum ribavirin concentration in Japanese patients with chronic hepatitis C who undergo combination PEG-IFN and ribavirin therapy. Serum creatinine-based renal function estimates might be predictive for the serum ribavirin concentration only in patients with a daily ribavirin intake of 800 mg or more.

Circulating matrix metalloproteinase-2 is associated with cystatin C level, posttransplant duration, and diabetes mellitus in kidney transplant recipients

Studies have indicated that matrix metalloproteinase-2 (MMP-2) is vital for the patient's condition after renal transplantation. Although the allograft survival rate has been improved, the relationships between various clinical parameters in stable graft function and serum MMP-2 still need to be clarified. In this study, gelatin zymography and enzyme-linked immunosorbent assay were employed to measure MMP-2 level in the plasma of 152 kidney transplant recipients, 41 chronic kidney disease patients, and 50 healthy control subjects. The creatinine and the MMP-2 levels in the transplant recipients were significantly greater (P < 0.001) than those of control subjects. Univariate and stepwise regression analysis demonstrated the MMP-2 level was associated with cystatin C level (P < 0.001), creatinine level (P = 0.036), proteinuria (P = 0.043), posttransplant days (P = 0.025), and posttransplant diabetes mellitus (P = 0.03). We conclude that circulating MMP-2 is associated with cystatin C, posttransplant duration, and diabetes mellitus in kidney transplant recipients and suggest that MMP-2 may be critical for graft survival.

Novel approaches to assessing renal function in cirrhotic liver disease

Renal dysfunction is common in patients with end-stage liver disease. Etiological factors include conditions as diverse as acute tubular necrosis, immunoglobulin A nephropathy and hepatorenal syndrome. Current standard tests of renal function, such as measurement of serum urea and creatinine levels, are inaccurate as the synthesis of these markers is affected by the native liver pathology. This article reviews novel markers of renal function and their potential use in patients with liver disease.

The upregulation of cystatin C in oral submucous fibrosis

Cystatin C is a 13kDa non-glycosylated basic protein belonging to cystatin family. It is consistently and dramatically upregulated in a variety of fibrotic diseases. The aim of this study was to compare cystatin C expression in normal human buccal mucosa and oral submucous fibrosis (OSF) specimens and further explore the potential mechanism that may lead to induction of cystatin C expression. Twenty-five OSF specimens and six of normal buccal mucosa were examined by immunohistochemistry. The activity of cystatin C from fibroblasts cultured from OSF and normal buccal mucosa were evaluated by using reverse-transcriptase polymerase chain reaction and enzyme-linked immunosorbent assay. Furthermore, the effect of arecoline, the major areca nut alkaloid, was explored. Cystatin C expression was significantly higher in OSF specimens (p<0.05) and expressed mainly by fibroblasts, endothelial cells, and inflammatory cells. OSF demonstrated significantly higher cystatin C expression than normal buccal mucosa fibroblasts both in mRNA and protein levels (p<0.05). In addition, arecoline was also found to elevate cystatin C mRNA and protein expression in a dose-dependent manner (p<0.05). Taken together, the data demonstrate that cystatin C expression is significantly upregulated in OSF from areca quid chewers and arecoline may be responsible for the enhanced cystatin C expression in vivo.

Serum cystatin C for the prediction of glomerular filtration rate with regard to the dose adjustment of amikacin, gentamicin, tobramycin, and vancomycin

Dosage regimes of aminoglycosides and vancomycin are modified according to the glomerular filtration rate (GFR). In 130 hospitalized patients who were administered amikacin, gentamicin, tobramycin, and vancomycin by intermittent intravenous infusion, we compared the predicted GFR values from the serum concentrations of creatinine (Cockcroft and Gault. Nephron. 1976;16:31-41) and cystatin C (Larsson et al. Scand J Clin Lab Invest. 2004;64:25-30) with respect to their relevance for proper dosage. In 83% and 67% of the cases, respectively, the serum levels of albumin and cholinesterase were below the corresponding lower limit of the reference range. The ratio of creatinine/cystatin C concentrations presented significant correlations with the predicted rate of creatinine production (r=0.762, P<0.001), serum albumin concentration (r=0.205, P<0.05), and catalytic serum concentrations of cholinesterase (r=0.207, P<0.05), gamma glutamyltransferase (r=-0.273, P<0.01), and alkaline phosphatase (r=-0.289, P<0.01). The GFR (mean+/-SD; median) predicted by the serum creatinine (84.0+/-35.1 mL/min/1.73 m; 82.6 mL/min/1.73 m) was significantly higher (P<0.001) than that predicted by the serum cystatin C (53.1+/-30.2 mL/min/1.73 m; 44.9 mL/min/1.73 m). The ratio between the GFR values predicted by creatinine and cystatin C had a highly significant negative correlation with the rate of creatinine production (r=-0.912, P<0.001). Furthermore, significant differences were found for the peak concentrations and clearances of amikacin and vancomycin estimated by means of the Abbottbase Pharmacokinetic Systems program, and using the GFR values predicted by the serum creatinine and cystatin C (P<0.005). In patients with hepatic dysfunction, the clearance of creatinine predicted by the Cockcroft-Gault formula leads to a significant overestimation of the GFR. Cystatin C seems to be a valid alternative as a GFR marker with regard to drug dose adjustment in these cases.

Variable expression of cystatin C in cultured trans-differentiating rat hepatic stellate cells

AIM: To study the expression of cystatin C (CysC), its regulation by transforming growth factor-β1 (TGF-β1) and platelet-derived growth factor (PDGF) and the potential interference of CysC with TGF-β1 signaling in this special cell type.

METHODS: We evaluated the CysC expression in cultured, profibrogenic hepatic stellate cells and trans-differentiated myofibroblasts by Northern and Western blotting and confocal laser scanning microscopy.

RESULTS: CysC was increased significantly in the course of trans-differentiation. Both TGF-β1 and PDGF-BB suppressed CysC expression. Furthermore, CysC secretion was induced by the treatment with TGF-β1. Although CysC induced an increased binding affinity of TGF-β receptor type III (beta-glycan) as assessed by chemical cross-linking with [¹²⁵I]-TGF-β1, it did not modulate TGF-β1 signal transduction as shown by evaluating the Smad2/3 phosphorylation status and [CAGA]-MLP-luciferase reporter gene assay. Interestingly, the shedding of type III TGF-β receptor beta-glycan was reduced in CysC-treated cells. Our data indicated that CysC expression was upregulated during trans-differentiation.

CONCLUSION: Increased CysC levels in the serum of patients suffering from liver diseases are at least partially due to a higher expression in activated hepatic stellate cells. Furthermore, TGF-β1 influences the secretion of CysC, highlighting a potentially important role of cysteine proteases in the progression of hepatic fibrogenesis.

Relationship between matrix metalloproteinase-2 activity and cystatin C levels in patients with hepatic disease

OBJECTIVES

A direct relationship between cystatin C levels and the severity of hepatic disease has been revealed in our previous study. This study was aimed to consider whether a correlation exists between matrix metalloproteinases (MMPs), which have been proven to be involved in liver cirrhosis, and cystatin C to reflect the severity of hepatic disease.

DESIGN AND METHODS

A total of 154 consecutive patients with various liver diseases were recruited to determine their serum levels of cystatin C, MMP-2 and-9, together with other hepatic parameters. These were compared with 40 normal controls.

RESULTS

Average levels of MMP-2 and cystatin C were significantly higher in patients while MMP-9 was significantly lower, as compared to controls. A linear regression analysis has revealed a direct relationship between cystatin C and MMP-2 (Y=83.39 + 270.56 X, R=0.38, P< 0.001), as well as between MMP-2 and the severity of liver diseases.

CONCLUSION

This is the first study to demonstrate a correlation between cystatin C and MMP-2, suggesting that there may be certain interactions between cystatin C and MMP-2 in patients with hepatic diseases.