From January 2010 to June 2010, 120 patients with chronic hepatitis C were enrolled. The diagnosis of decompensated HCV-induced cirrhosis was based on the American Association for the Study of Liver Diseases Clinical Guideline for Hepatitis C (2004).

All enrolled patients were naive to antiviral treatments. Other inclusion criteria were: (1) HCV RNA >500 copies/mL; (2) absence of complications such as gastrointestinal bleeding, hepatic encephalopathy, and primary liver cancer; and (3) liver function defined as Child-Pugh grade B or C based on serum bilirubin, serum albumin, presence of ascites, presence of hepatic encephalopathy, and prothrombin time. Patients with hypersplenism were also enrolled. Exclusion criteria were: (1) infection with hepatitis A, B, D, or F virus, Epstein-Barr virus, cytomegalovirus, or human immunodeficiency virus; and (2) presence of alcoholic or drug-induced liver diseases, or severe heart, brain, or kidney disease.

A total of 120 patients meeting the inclusion criteria were enrolled. Patients were considered as part of the treatment group (n = 90) or control group (n = 30), based on whether they opted to receive antiviral therapy. The study was approved by the Institutional Review Board of the hospital, and informed consent was obtained from all study participants.

Determination of therapeutic efficacy: The primary endpoints were: (1) SVR, defined as HCV RNA undetectable or < 500 copies/mL for at least 24 wk after treatment discontinuation[11]; and (2) relapse, defined as HCV RNA undetectable or < 500 copies/mL during antiviral therapy, but becomes detectable at 24 wk after treatment discontinuation. The secondary endpoints were disease progression (defined as an increase of 2 or more in the Child-Pugh score), presence of primary hepatocellular carcinoma, renal dysfunction, spontaneous bacterial peritonitis, variceal bleeding, or death due to liver disease[12].

Measures: Patients in the treatment group were evaluated for serum HCV antibodies, liver function, HCV RNA, coagulation function, thyroid function, and alpha foetoprotein as well as liver computed tomography. Routine blood and urine tests were performed before the start of the study. Routine blood and liver function tests were performed weekly in the first month, then once every 4 wk during the study period and once every 8 wk for 24 wk after discontinuation of treatment. Quantitative detection of HCV RNA was done immediately prior to treatment (baseline), at 24 and 48 wk after treatment, and 6 mo after discontinuation of treatment. HCV RNA levels were quantitated by real-time polymerase chain reaction using a kit from the Roche company.

Patients in the control group were evaluated for liver function and HCV RNA levels. Routine blood tests and colour ultrasonography of the liver were done every 12 wk. All patients were assessed for disease progression.

Treatment regimen and follow-up: All participants received symptomatic and supportive treatment, including treatment for reducing levels of transaminase and bilirubin and supplemental albumin. For patients in the treatment group, those who had a neutrophil count ≥ 1.0 × 10⁹/L, platelet count ≥ 50 × 10⁹/L, and haemoglobin > 10 g/L were treated additionally with both pegylated interferon α 2a (Peg-IFNα-2a) and ribavirin (RBV). The initial dose of Peg-IFNα-2a was 180 μg/kg subcutaneously. Peg-IFNα-2a dosage was reduced to 90 μg/kg once weekly when neutrophil or platelet counts decreased to ≤ 0.75 × 10⁹/L or < 50 × 10⁹/L, respectively. The dose was returned to 180 μg/kg if neutrophil and platelet counts increased to > 0.75 × 10⁹/L and ≥ 50 × 10⁹/L, respectively, after 2 wk. Treatment was discontinued if neutrophil count was ≤ 0.5 × 10⁹/L or platelet count was < 30 × 10⁹/L. Patients tolerating the standard Peg-IFNα-2a dose of 180 μg/kg weekly were treated for 48 weeks. Patients who could not tolerate the standard dose were treated with the reduced dose of 90 μg/kg once weekly for up to 72 wk.

Patients with haemoglobin >100 g/L were initially treated with a standard dose of RBV (genotype 1: 1200 mg/d for patients with body weight > 75 kg and 1000 mg/d for patients with body weight ≤ 75 kg; non-genotype 1: 1000 mg/d for patients with body weight >75 kg and 800 mg/d for patients with body weight ≤ 75 kg). RBV dosage was reduced when haemoglobin levels decreased to ≤ 100g/L after the dosage increase. RBV treatment was discontinued when haemoglobin levels were ≤ 80 g/L. Patients tolerating the standard dose of RBV were treated for 48 wk. Patients developing cytopaenia during the treatment period were treated with cell growth-stimulating factor and/or erythropoietin. All patients were followed for 3 years.

A 3.0T MRI unit (Philips Medical Systems) was used[6]. All imaging was conducted after an overnight fast. An enveloping transmitter coil and a separate surface receiver coil were used. Both coils were double-tuned for protons at 64 MHz and phosphorus at 26 MHz. The proton signal was used to obtain a T1-weighted image (TR/TE, 800/16) in the axial plane to confirm patient positioning. The 31P MR spectra were localised to a centrally placed voxel within the liver by use of an image-selected in vivo spectroscopy sequence (voxel size, 70 mm × 70 mm × 70 mm; TR, 10000; number of signals averaged, 48). A voxel location within the right liver away from major vessels was used for each patient and was consistent for all baseline and follow-up images. The total examination time was 40 min with a 10-min acquisition time for the 31P MRS sequences. All patients underwent baseline 31P MRS before the start of antiviral treatment, and all underwent follow-up imaging 6 mo after the start of treatment.

Quantitation of the 31P signals was performed in the time domain with the advanced method for accurate, robust, and efficient spectral fitting (AMARES) algorithm included in the Magnetic Resonance User Interface (MRUI) software program (http://www.mrui.uab.es/mrui). Anonymity was assured and MR spectra were analysed by one blinded observer. The spectra were rechecked by another blinded observer. Peak areas for PME, PDE, inorganic phosphate, and the three nucleoside triphosphate moieties (γ, α, and β) were obtained with respect to the total phosphorus signal intensity. Because of previous findings highlighting the utility of the PME/PDE ratio, this index was used for further statistical analysis. Data from a bank of 15 age-matched healthy volunteers without a history of liver disease were used for comparison.

Age and baseline HCV RNA levels were normally distributed and presented as mean and standard deviation. Differences in age and baseline HCV RNA levels between the two groups were tested by the independent two-sample t-test. Child-Pugh scores were non-normally distributed and are presented as median and inter-quartile range. Differences in Child-Pugh scores between the two groups were tested by the non-parametric Mann-Whitney test. Other categorical variables are presented as number and percentage, and categorical variables were compared using the Fisher’s exact test. Statistically significant variables from the univariate analyses were used in the multivariate analysis. All statistical tests were two-sided, and a P-value < 0.05 was considered statistically significant. All statistical analyses were performed using the SPSS 19.0 software (SPSS Inc, Chicago, IL, United States).

As shown in Table 1, 120 patients who met the inclusion criteria were enrolled. Among them, 90 patients had sufficient blood cell counts for antiviral therapy. The remaining 30 patients, who refused antiviral therapy, were placed in the control group. Patients in the treatment group were significantly younger than those in the control group (mean age 52.7 vs 58.3 years, respectively, P < 0.001). There were no significant differences between the two groups in baseline HCV RNA levels. In addition, baseline MELD scores were not significantly different between the treatment and control groups (Table 1). Although baseline Child-Pugh scores, total bilirubin, and hepatic encephalopathy were not different between the two groups, significant differences in serum albumin, international normalised ratio (INR) for prothrombin time, and ascites were observed between the treatment and control groups (P = 0.002, P = 0.018, and P < 0.001, respectively).

The PME/PDE ratios at 6 mo after the start of antiviral therapy in the Child B and C groups were significantly higher than those before therapy, but this was not seen in Child-Pugh A group (Table 2).

Sixty-nine patients responded to antiviral treatment with a sustained viral response. In 54 of these patients, the PME/PDE ratio had decreased toward normal on follow-up MRS. Figure 1 is the graph of a responder whose spectra changed after treatment, showing a decrease in PME/PDE ratio. Fifteen of the 21 virological nonresponders had PME/PDE ratios on follow-up imaging similar to the baseline values. Another two nonresponders had an increase in the PME/PDE ratio on follow-up imaging (Table 3). An unchanged PME/PDE ratio was defined as a difference of not more than 0.03 in comparison with the baseline ratio. An increase was defined as a > 0.03 increase in PME/PDE ratio in comparison with the baseline value. A decrease in PME/PDE ratio was defined as a > 0.03 reduction in the ratio compared with the baseline value.

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Figure 1 Change in phosphomonoester to phosphodiester ratio between baseline and after treatment in the responder group (A), and the nonresponder group (B). PME/PDE: Phosphomonoester/phosphodiester.

Hepatitis C virus (HCV) is one of the leading causes of liver disease worldwide. Liver biopsy remains the gold standard for providing the stage (extent of fibrosis) and grade (degree of NI activity) of HCV-related liver disease, but this invasive procedure is not without risk. Thus, the impetus to find a reliable and repeatable biomarker of disease activity and response to treatment has a renewed focus.

Clinical (in vivo) phosphorus-31 magnetic resonance spectroscopy (31P MRS) is the only noninvasive technique that can be used to provide direct localised biochemical information on hepatic metabolic processes.

This study was the first attempt to use 3.0T 31P MRS in assessment of response to antiviral therapy for chronic hepatitis C. It assessed the value of 3.0T 31P MRS, a noninvasive technique, in testing response to antiviral therapy for chronic hepatitis C. The technique could provide biochemical information on hepatic metabolic processes. The phosphomonoester (PME)/phosphodiester (PDE) ratio can be used as an indicator of response to antiviral treatment in chronic hepatitis C patients.

This study suggests that 31P MRS could provide biochemical information on hepatic metabolic processes. The PME/PDE ratio can be used as an indicator of response to antiviral treatment in chronic hepatitis C patients.

Clinical (in vivo) 31P MRS is the only noninvasive technique that can be used to provide direct localised biochemical information on hepatic metabolic processes. A typical 31PMR spectrum of the human liver in vivo contains resonances that can be assigned to PMEs, containing information from sugar phosphates in the glycolytic pathway and from cell membrane precursors such as phosphoethanolamine and phosphocholine; and to PDEs, containing information from the endoplasmic reticulum and from cell membrane degradation products such as glycerophosphorylcholine and glycerophosphorylethanolamine, in addition to signals from inorganic phosphate and nucleotide triphosphates, including adenosine triphosphate. Many studies have reported a good correlation between elevated PME resonance and decreased PDE resonance in cirrhosis. The ratio of PME to PDE has traditionally been viewed as an index of cell membrane turnover and thus provides an indirect measure of grading of liver histology.

This is a good descriptive study in which authors attempt to use 3.0T 31P MRS in assessment of response to antiviral therapy for chronic hepatitis C. 3.0T 31P MRS represents a new noninvasive technique that provides biochemical information on hepatic metabolic processes and response to antiviral therapy for chronic hepatitis C.