الفهرس 
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Abstract
Hepatitis B is an infectious disease caused by the hepatitis B virus (HBV) which affects the liver. It can cause both acute and chronic infections. In 2015, hepatitis B resulted in 887,000 deaths, mostly from complications (including cirrhosis and hepatocellular carcinoma). National and regional prevalence ranges from over 10% in Asia to under 0.5% in the United States and northern Europe.
Chronic hepatitis B virus is an important public health problem, with more than 3.5 million chronic HBV carriers worldwide. Egypt is consider to be region of intermediate prevalence for HBV infection.
Early diagnosis remains the key to effective therapy of hepatic fibrosis. The assessment of liver fibrosis is not only important to determine the prognosis of the disease and to identify patients who require antiviral therapy.
Liver biopsy was traditionally considered to be the gold standard for the staging of fibrosis. However, sampling error can lead to underestimation of the degree of liver fibrosis e.g. small or fragmented tissues. Moreover, the biopsy is not suitable for repetition because of it invasiveness and tendency to cause major complications, including hemorrhage and death. The latter’s and others, therefore, can subtract from goodness or interpretation of the results of liver biopsy. Therefore, liver biopsy has been challenged in the past decade by non-invasive techniques.
These techniques rely on two distinct but complementary approaches: a ‘biological’ approach, based on the quantification of biomarkers of fibrosis in serum, and a ‘physical’ approach, based on the measurement of liver stiffness using elastography-based technologies. Advantages of serum biomarkers include their high applicability (>95%) and good reproducibility.
Many serum biomarkers have been evaluated to determine the stage of liver fibrosis. The so called direct markers reflect the deposition or removal of the extracellular matrix in the liver. These include glycoproteins such as serum hyaluronate, laminin, YKL-40, collagens such as procollagen III N-peptide and type IV collagen, collagenases and their inhibitors such as matrix metalloproteases and tissue inhibitory metalloprotease-1.
The so called indirect markers include factors that can be measured in routine blood tests, such as the prothrombin index, platelet count and ratio of aspartate to alanine aminotransferase (AST/ALT), which indicate alterations in hepatic function.
The indirect markers based scores which were selected for comparison with chitin related proteins include AAR, API, Fib-4 index, Fibro Q index, GUCI, King’s score, APRI, CDS, FI, AGE to AST ratio and LOK (Model 3). The results from measurements of direct and indirect markers can be combined and used as a diagnostic tool.
This study was carried out at the outpatient’s clinic at the Egyptian Liver Hospital, Sherbin, Dakahlia, Egypt. The patients were randomly chosen from adult males and females. A group of individuals (adult males and females) free from any disease, especially hepatitis B virus, were taken as controls.
An informed consent was taken from each participant before enrollment in the study (n=91). This study was conducted on 71 subjects who were divided into 5 groups according to liver biopsy and transient elastography.
The present study was conducted on seventy one individuals which were classified into five groups (F0, F1, F2, F3 and F4). These pathological groups were recombined to form new 4 classifications; ,namely patients with non-significant fibrosis (F0 and F1), those with significant liver fibrosis (F2, F3 and F4), patients with non-severe fibrosis (F0 , F1 and F2) and those with severe fibrosis (F3 and F4). A group of apparently normal and healthy which were free from any disease, especially liver disorder (n = 20) were used as a control group.
Aim of this study:
The aim of this study is to assess the degree of liver damage accompanying hepatitis B virus infection using fibrosis markers. These markers include chitinase like proteins; namely YKL-40 (direct fibrotic marker) and enzymes (N-acetyl-β-D-glucosaminidase (NAG) and Acid mammalian chitinase (AMCase) (direct markers). Besides, some of the routine laboratory tests were included.
The correlation of the chitin related protein with the histological features of fibrosis to predict the presence, absence or the severity of the fibrosis and/or cirrhosis in such patients will be discussed.
Also, the correlation of the levels of these chitin-related patients with the already used non-invasive and indirect scores of hepatic disorders will be illustrated.
Six ml venous blood was withdrawn from each individual;1.8 ml of blood was collected in sodium citrate tube for determination of prothrombin time, then 1.2 ml of blood was collected in EDTA tube for determination of complete blood picture, and other three ml of blood was collected in gel vacationer tube, then left for 10 minutes in water bath at 37°C until clot, then centrifuged at 2000 rpm for 10 minutes for separation of serum which was transferred into another tube and kept frozen at -80°C to detect YKL-40, NAG, AMCase and liver functions.
The most important findings of the present study was demonstrated as follow:
1- The mean level of YKL-40 in sera of patients which were HBV positive was extremely significantly increased when compared with that of the control group (P<0.0001). Also, YKL-40 was highly significantly increased when patients with non-significant fibrosis were compared with that of patients with significant fibrosis (P<0.0001). In addition, YKL-40 was extremely significant when used for discriminating patients with non-severe fibrosis from those with severe fibrosis (P<0.0001).
2- The diagnostic power which include the sensitivity, specificity, predictive value of positive (PPV), predictive value of negative (NPV) and area under curve (AUC) were 86,100, 100, 87.2 and 0.941 when used for discriminating patients with non-significant fibrosis were compared with that of patients with significant fibrosis (P<0.001). Also, the parameters of diagnostic power were 95, 74, 60, 97 and 0.932 when used for discriminating patients with non- severe fibrosis were compared with that of patients with severe fibrosis (P<0.001).
3- When the numerical value of YKL-40 for each patients was combined with the corresponding numerical values of AAR, API, Fib-4 index, Fibro Q index, GUCI, King’s score, APRI, CDS, FI, AGE to AST ratio and LOK (Model 3) the parameters of the diagnostic powers were significantly improved except that of the sensitivity of APRI when patients with non-significant fibrosis were compared with that of patients with significant fibrosis. The same findings were reported for AAR, API, Fib-4 index, GUCI, CDS, FI, AGE to AST ratio and LOK (Model 3) when patients with non- severe fibrosis were compared with that of patients with severe fibrosis.
4- The correlation between the individual results of YKL-40 and those of the 11 selected scores were done (correlation coefficient, r). Weak or no correlations were found between YKL-40 and those with scores LOK (Model 3) and AGE to AST ratio in non-significant versus significant fibrosis and in non-severe versus severe fibrosis.
5- YKL-40 was strong correlated with those of NAG in both classifications non-significant versus significant fibrosis and in non-severe versus severe fibrosis.
Further, moderate correlations were between YKL-40 levels and age (r=0.531), Albumin (r=0.508), FI (r=0.551), CDS (r=0.522), API (r=0.536), FIB-4 (r=0.617) and FIBQ scores (r=0.573). YKL-40 was fairly correlated with RBCs (r=0.326), direct bilirubin (r=0.461), platelets count (r=0.380), SGOT (r=0.350), AAR (r=0.384) and GUCI scores (r=0.488). On the other hand, weak or no correlations were also found between YKL-40 and Hb (r=0.05), WBCs (r=0.136), total bilirubin (r=0.006), SGPT (r=0.061) and INR (r=0.202).
6- The mean activity of serum NAG was increased in sera of patients which having positive HBV when its activity was compared with that of the control group (P<0.001). In addition, the activity difference was highly significant when patients with non-significant compared with that of patients with significant fibrosis(P<0.001). In addition, the mean NAG activity was extremely significant when comparing such activity in patients with non-severe with those with severe fibrosis (P<0.001).
7- The mean NAG activity was found to be moderately correlated with Age, APRI, FI, CDS, API, FIB4, FIBQ, KING score. In addition, The individual levels of NAG were found to be fairly correlated with RBCs, platelets count, direct bilirubin, GOT, AAR and GUCI in both groups. On the other hand, NAG individual activity in sera of HBV infected patients were found to be weakly or no correlated with Hb, WBCs, total bilirubin, GPT, INR, AGE/AST ratio and LOK Mode in group 1 and group 2.
8- A strong negative correlation between YKL-40 levels, as one of the extracellular matrix (ECM) components, and that of NAG in both classifications. Such finding confirm the interrelationship between NAG activity and ECM remodeling. Thus, NAG activity was considered as a direct marker of hepatic disorders.
9- In this study, AMCase activity was assayed in sera of chronic hepatitis B virus. The parameter of Its diagnostic power was 97, 14, 55, 83 and 0.522 for the sensitivity, specificity, positive predictive value, negative predictive value and AUC, respectively in non-significant and significant fibrosis (P=0.754). They were 60, 59, 37, 78 and 0.560, respectively during differentiating patients with non-severe from those with severe fibrosis (P=0.370).
Conclusion:
from the results of the present study, YKL-40 level and NAG activity can be used to assess hepatic fibrosis in HBV infected patients. Otherwise their levels can be added to those of the selected non-invasive scores to precisely evaluate hepatic damage. The hope is to reduce the need of liver biopsy in the future.
We recommend to use the results of this thesis on out patients of hepatic centers and university hospital. This is because the parameters included in this study are easy to perform, simple, sensitive and to somewhat, specific. In addition, encouragement and funding of such researches are advisable.