Acute phase reactants (APRs) plays vital role on the regulation of inflammation and repairment of tissue damage.13
Synthesis and catabolism of APR is regulated by interleukin (IL-1, IL-6, IL-11), tumor necrosis factor (TNF), leukemia inhibitor factor, and oncostatin M. Tissue damage is associated with acceleration of positive APR (ceruloplasmin, C3, A1AG, A2MG, alpha-1 antitrypsin, alpha-1 antichymotrypsin, fibrinogen, haptoglobulin, CRP, and serum amyloid A protein) or deceleration of negative APR (prealbumin, albumin, transferrin, and alpha-2 glycoprotein) synthesis.14
Tsui et al.15
found HCV seropositivity to be associated with lower lipids, CRP and fibrinogen levels, and higher levels of IL-6 and TNF-α.
Liver biopsy is an invasive procedure that has been associated with complications; morbidity risk of 0.3% to 0.6% and mortality risk of 0.05%. Bourliere et al.16
combined noninvasive procedures like Fibroscan and Hepascore (Echosens, Paris, France), and concluded that diagnostic accuracy was increased and necessitance of liver biopsy was diminished.
HCV RNA and ALT are recent virologic and biochemical parameters to evaluate response to treatment in CHC. Early virologic response is determined by negative HCV RNA or reduction of 2 log by PCR analysis at the 12th week of therapy.17
APR may provide supplementary data as a cost-effective and feasible parameter in patients with CHC and may predict the response to therapy.
Patients with chronic viral hepatitis have increased levels of IL-1 and TNF-α; and elevated levels of cytokines stimulate the production of CRP. However, exact role of CRP on the progression of hepatitis is still unknown and remains to be determined. Shima et al.18
compared CRP levels of patients with chronic hepatitis B (CHB) or CHC and mentioned correlation between CRP and histologic activity in patients with CHB. Significant correlation exists between serum ALT and CRP levels and also between disease progression and CRP in patients with CHB. However, it was nonsignificant in patients with CHC. In contrast to patients with nonA-nonB hepatitis, Atono et al.19
determined significantly higher levels of CRP in patients with acute hepatitis A or B. Huang et al.20
determined significantly higher high-sensitivity CRP (hsCRP) levels in a study conducted on 95 patients with CHC and 95 healthy controls, and also achieved significant decrease in hsCRP level following to treatment with pegylated IFN and ribavirin. Bíró et al.21
examined the effect of IFN-α-2b therapy on APRs. They observed elevated complemant proteins (C-9 and C1-INH) subsequent to antiviral therapy for 3 months. Increment in C-9 and C1-INH was strongly correlated with virological response.21
In our study, CRP levels were similar between patients with CHC and healthy control group however decrease in CRP levels between initial evaluation and 4th and 12th week was significant (p=0.005 and p=0.014, respectively).
Alcoholic patients with CHC have diminished response to IFN therapy and significantly higher levels of CRP than nonalcoholic patients with CHC subsequent to IFN therapy.22
carried out a study in 20 patients with CHC that underwent to IFN-α-2a therapy and determined no significant difference between CRP and albumin levels at the 2nd and 12th week. We observed no significant difference between responders and nonresponders in terms of CRP levels at baseline evaluation and 12th week. Elevation of CRP was significant between baseline evaluation and 4th or 12th week; however, difference between baseline evaluation and 48th week was nonsignificant. In contrast to previous reports, IFN use is considered to be the cause of elevation of CRP levels.
Ferritin levels were significantly higher in patients with CHC than healthy control group; similar to published data.24
Stam et al.25
emphasized that IFN therapy is related with increase of synthesis and secretion of ferritin. Exact mechanism of elevation of ferritin levels subsequent to IFN therapy is unknown; however, it is possibly related with liver tissue damage. Some other recent reports mentioned that combined IFN and ribavirin therapy is associated with decrease in the levels of serum iron, ferritin, transferrin, and increase amount of transferrin receptor.26
Our patients exhibit significantly higher ferritin levels at 4th, 12th, and 48th week. Early virologic response was evaluated at the 12th week and ferritin levels of responders were nonsignificantly higher than nonresponders. No significant correlation was observed between HCV RNA and ferritin levels. Elevated ferritin level is considered to be related with IFN therapy.
Nonresponders to IFN therapy have high levels of iron saturation.27
Hepatic fibrogenesis is stimulated by both liver tissue damage by viral infection induced oxygen radicals and increased liver iron storage.28
In a study from Turkey, 21 and 19 patients underwent to IFN+desferrioxamine and IFN alone, respectively.29
Ferritin and HCV RNA levels were significantly lower and histologic activity was better in the former group. Serum iron, ferritin levels and transferrin saturation were significantly higher in African-Americans with CHC and response to IFN therapy was significantly poorer in this group of patients.30
In contrast to relation of liver iron concentration and response to therapy, elevated level of ferritin is associated with poorer response to therapy (combined ribavirin and pegIFN therapy).31
Significant relation exist between serum iron level and hepatic fibrosis in patients with CHC. Serum ferritin level indicates the severity of hepatic fibrosis; independent from liver iron deposition.32
Serum iron level and liver iron storage are extremely high in IFN-nonresponders. Excessive iron load leads to poorer response to IFN however improves by iron chelation.33
Ferritin levels of our patients that response to IFN were nonsignificantly lower than nonresponders. The presence of increased hepatic iron, which is present in 30% to 40% of patients with CHC, has been linked to more severe liver disease and poorer response to IFN monotherapy. Iron depletion by phlebotomy has been shown to be associated with decreased incidence of decompensation and HCC.15
Serum transferrin levels exhibit hepatic iron load and related with poorer response to IFN therapy.33
Kalabay et al.34
performed a study in 40 patients with CHC that underwent to IFN-α-2b therapy. Patients responsive to treatment had significantly lower levels of transferrin than unresponsive group; however, CRP levels were similar between two groups.34
Patients with CHC usually higher levels of transferrin saturation.33
Iron load influences the natural course of HCV infection by leading to hepatic dysfunction and macrophage activation.35
Combined IFN and ribavirin therapy decreases serum iron, ferritin, and transferrin levels and increases the density of transferrin receptors.26
Transferrin levels of our patients significantly decreased from baseline point to 48th week. No significant difference was observed between transferrin levels of responders and nonresponders at the 12th week of therapy. This may be related to the fact that responders had higher transferrin levels at the initial evaluation.
A2MG, haptoglobulin, gammaglutamyl transferase (GGT) and total bilirubin are serum predictors of hepatic fibrosis.36
A2MG is an APR; produced by hepatocytes and stellate cells, inhibits catabolism of matrix proteins and hepatic fibrosis. Fibrogenesis and cytokine induced hepatocyte growth factor stimulates the synthesis of A2MG while inhibiting the synthesis of haptoglobulin.36
Patel et al.37
determined high levels of A2MG in patients with moderate to severe fibrosis. Patients with chronic persistant hepatitis and cirrhosis have increased density of lymphocytes and fibroblasts in liver tissue and higher levels of serum IgG and A2MG.38
Poynard et al.39
stated that serum markers like A2MG, haptoglobulin, GGT, and total bilirubin may have a predictive role on the progression of fibrosis and virologic response in patients with CHC without possible harmful effects of invasive methods such as liver biopsy. Ho et al.40
carried out a study to assess the predictive role of noninvasive serologic biomarkers such as A2MG, vitamin D binding protein (VDBP) and apolipoprotein AI (ApoAI). They revealed that the serum concentration of A2MG significantly increased from mild to advanced fibrosis however the protein levels of VDBP and ApoAI were significantly higher in normal or mild fibrosis, when compared to those in advanced fibrosis (both p<0.01). A2MG levels were significantly higher in our patients with CHC than healthy control group. Nonresponders had nonsignificantly higher levels of A2MG than responders. A2MG levels of our patients significantly decreased at the 4th and 12th week of treatment; however, it did not remain stable at the 48th week.
Serum albumin level and thrombocyte count indicate the severity of liver damage.41
Thrombocyte count lower than 140,000/mm3
, AST/ALT >1, globulin/albumin >1 are considered to be the predictors of progression to cirrhosis.42
Volchkova et al.43
reported that patients with acute viral hepatitis have low levels of albumin, prealbumin, transferrin and high levels of haptoglobulin. However, patients with CHC had low levels of haptoglobulin as well as the other markers. No significant difference was observed in terms of albumin levels at the 4th, 12th, and 48th week. Nonresponders had nonsignificantly but remarkbly lower albumin levels than responders at the baseline evaluation (p=0.054). Negative correlation exist between HCV RNA and albumin levels at the 48th week and between ALT and albumin levels at the 12th week. Low albumin levels at the baseline evaluation is associated with poorer response to therapy.
A1AG, an internal membrane protein related with collagen overproduction, is synthesized by neutrophils, lymphocytes, monocytes, and hepatocytes. Stam et al.25
established elevated A1AG levels at the 4th week and at the 6th month of IFN-α-2b therapy.26
Nonresponders had higher A1AG levels at the 12th week when compared to responders. There was a significant increase in A1AG levels during treatment period however nonresponders exhibit remarkably higher increase in A1AG levels. Patients with CHC have increased levels of A1AG; however, elevation of A1AG subsequent to antiviral therapy is considered to associated with effect of IFN.
The present study has some limitations. First, sample size in our study was relatively low. Statistical significance may be enhanced by increasing sample size. Second limitation of the study was that ALT and HCV RNA are globally accepted parameters in predicting response to treatment in patients with CHC. However combining ALT and HCV RNA with APP may be more accurate to predict response to antiviral therapy. Third, patients in our study have different duration of CHC. Heterogenity in the duration of CHC may have significant impact on response to treatment. Also racial factors may play important in response to antiviral therapy. Ioannou et al.30
mentioned the effect of race and stated African-American patients with CHC exhibit poorer response to IFN therapy when compared to patients from other origin.
In conclusion, variations of ferritin, A2MG, albumin, CRP, transferrin, and A1AG levels would not be an alternative to virologic and biochemical parameters as a predictor of early response to therapy in patients with CHC. However these parameters may provide supplementary data in predicting response to treatment. Further studies with large number of individuals are required to establish these data.