Expression and clinical significance of antinuclear antibody in hepatitis C virus infection

Prevalence and Significance of Autoantibody Seropositivity in Children with Wilson's Disease

Autoantibodies occur in healthy subjects as well as in children with Wilson's disease (WD), but their prevalence and significance are unknown. Thus, we aimed to assess the prevalence of autoantibodies and autoimmune markers, and their relationship to liver injury in WD children. The study included 74 WD and 75 healthy children as a control group. Patients with WD underwent transient elastography (TE) examinations, as well as determination of liver function tests, copper metabolism markers, and serum immunoglobulins (Ig). In the sera of the WD patients and controls, anti-nuclear (ANA), anti-smooth muscle, anti-mitochondrial, anti-parietal cell, anti-liver/kidney microsomal, anti-neutrophil cytoplasmic autoantibodies, and specific celiac antibodies were determined. Among the autoantibodies, only the prevalence of ANA in children with WD was higher than in the controls. There was no significant relationship between the presence of autoantibodies and liver steatosis or stiffness after TE. However, advanced liver stiffness (E > 8.2 kPa) was related to IgA, IgG, and gamma globulin production. The type of treatment did not influence the prevalence of autoantibodies. Our results suggest that autoimmune disturbances in WD might not be directly related to liver damage as expressed by steatosis and/or liver stiffness after TE.

A retrospective study of prevalence and pattern of international consensus on ANA patterns among patients with hepatitis C virus infection

Background

A previous study reported a 30% prevalence of various autoantibodies among patients with hepatitis C virus (HCV) infection. The International Consensus on Anti-Nuclear Antibody (ANA) Patterns was recently introduced to classify ANA patterns based on immunoassay on HEp-2 cells. There is no previous report with this newly developed classification to evaluate patients with HCV infection. The study aims to study the prevalence and pattern of ANA patterns among HCV-infected patients.

Methods

We retrospectively analyzed the medical records of patients with HCV infection from September 2020 to June 2021 at our institution. A positive ANA is defined as a titer of more than 1:320. We compared patient features among the positive and negative groups.

Results

Overall, 258 patients were enrolled-184 patients with negative ANA and 74 patients (28.7%) with positive ANA. The mean age was 67.3 in ANA positive group and 61.2 ANA negative group. Female was prominent with ANA positive and accounted for 63.5%. The most detected ANA pattern was AC-1(homogeneous) (25.9%), followed by AC-4(fine speckled) (25.2%) and AC-21(anti-mitochondrial antibody) (9.6%). In ANA positive group, we found a trend of lower HCV viral load (5.72 log₁₀ IU/ML vs. 6.02 log₁₀ IU/ML), lower alanine aminotransferase level (39.5 U/L vs. 44 U/L), and higher advanced fibrosis (F3 and F4) (38.5% vs. 26.1%). In addition, higher positive ANA (more than 1:640) is significantly associated with lower estimated glomerular filtration rate (eGFR) (77.76 vs. 87.94 mL/min/1.73 m², P = 0.044).

Conclusions

A high prevalence (28.7%) of ANA was found in patients with chronic hepatitis C. The presence of positive ANA is not related to the severity of their hepatic manifestation. However, higher positive ANA was significantly associated with lower eGFR.

Frequent occurrence of low-level positive autoantibodies in chronic hepatitis C

Evidence of autoimmune disease associated with hepatitis C virus (HCV)-infection has important clinical implications. A systematic profile of these autoantibodies in relevant clinical cohorts relative to healthy controls is needed to better inform current standard of care for chronic hepatitis C. Samples from an Australian cohort of chronic HCV-infected subjects (n=127) were tested for the presence of 19 diagnostic autoantibodies and compared with data available from a control cohort representing a general Caucasian population (n=198). Chronic HCV-infected individuals had a greater number of autoantibodies than controls (p<0.0001). Anti-nuclear antibodies (ANA) followed by anti-smooth muscle antibodies (SMA) were the most frequently detected autoantibodies within the HCV cohort and significantly more than in the control cohort (p<0.0001 and p=0.006, respectively). However, for most autoantibody assays the 95th percentile approximated the reference value for positivity. None of the autoantibodies were significantly associated with age or sex for the HCV cohort, except SMA positivity that was significantly higher in chronic HCV-infected male subjects (p<0.0001). Autoantibodies found in chronic HCV-infected subjects were commonly low positive and not disease-specific. Accordingly, general screening for autoimmunity in HCV-infected subjects should not be performed unless there is high clinical suspicion of an underlying autoimmune disease.

Anti-rod and ring antibodies in patients with chronic hepatitis C using direct-acting antivirals

Anti-rods and rings (anti-RR) antibody induction is related to the combination of interferon and ribavirin in the treatment of hepatitis C virus (HCV) infection. If the main factor leading to this autoimmune reaction is the combination of these drugs, is not well known, but in vitro studies shows that ribavirin alone can induce rods and rings structures. New direct-acting antivirals (DAAs) permit HCV treatment without needing interferon but may be associated with ribavirin in the most difficult-to-treat patients. The aim of this study is to evaluate the occurrence of anti-RR in patients with chronic HCV infection, before and after 12 weeks of treatment with DAAs, with and without ribavirin. From Jun 2016 to Oct 2017, 52 HCV-infected patients were screened for anti-RR before and after DAA therapy, including sofosbuvir, daclatasvir, simeprevir, and ribavirin. Serum samples were analyzed using indirect immunofluorescence. The anti-RR was present in 11 (21%) of the 52 patients (51.9% male and mean age of 59.1 years) before using DAAs. All of them had been previously treated and previous exposed to interferon/ribavirin, with exposure time to ribavirin associated with the presence of anti-RR. After 12 weeks of DAA treatment, 3 patients (5.7%) developed the antibody in low titers, and two of them (66%) were interferon/ribavirin experienced. Only one of the 29 naïve patients (3.44%) developed anti-RR during the current treatment. Anti-RR was present in patients previously treated with interferon/ribavirin and can emerge after DAA treatment probably at a lower frequency than after interferon/ribavirin treatment.

Long-term persistence of anti-rods and rings antibodies in patients with chronic hepatitis C after antiviral treatment

Anti-rods and rings (anti-RR) antibodies are related to hepatitis C virus (HCV) in patients treated with pegylated interferon (PEG-IFN) and ribavirin (RBV). Only RBV induces rods/rings structures in vitro; but in vivo, the antibody appearance is related to the combination of these drugs, because data about patients using just one of these drugs alone is missing. Some studies suggest disappearance of these antibodies over time. The aim of this study was to describe the occurrence of anti-RR in patients with chronic hepatitis C treatment-naïve or previously PEG-IFN/RBV-experienced, evaluating the persistence of anti-RR antibodies long after PEG-IFN/RBV treatment. From 2016 to 2017, 70 HCV-infected patients were screened for anti-RR using indirect immunofluorescence. Demographic and clinical data about previous treatments against HCV were assessed. Thirty-four patients (49%) had been previously treated with PEG-IFN/RBV and the average time since they had received the last antiviral treatment was 85.4 months. Anti-RR seropositivity was detected in 16 patients (23%), and all of these had used PEG-IFN/RBV (corresponding to 47% of experienced patients). Previous antiviral treatment and previous exposure time to RBV were associated with anti-RR positivity. Median time elapsed since last treatment was similar between anti-RR-positive and anti-RR-negative patients. Anti-RR seropositivity was not observed in treatment-naïve patients, but was detected in almost half of patients previously treated with PEG-IFN and RBV, even after a long period without exposure to these drugs. This antibody was related to extended prior exposure to ribavirin.

Autoantibodies in chronic hepatitis C virus infection: impact on clinical outcomes and extrahepatic manifestations

Goals

To examine the role that autoantibodies (auto-abs) play in chronic hepatitis C virus (HCV) regarding demographics, presence of extrahepatic manifestations and long-term outcomes in a large US cohort.

Background

Auto-abs have been reported to be prevalent in patients with chronic HCV infection, but data on the natural history of these patients are limited.

Study

The study included 1556 consecutive patients with HCV without concurrent HIV and/or HBV who had testing for antinuclear antibody (ANA), antimitochondrial antibody (AMA), antismooth muscle antibody (ASMA) and/or antiliver kidney microsomal antibody (LKM). Primary outcomes included development of cirrhosis, hepatic decompensations, hepatocellular carcinoma (HCC), mortality and/or sustained virological response (SVR) to antiviral therapy.

Results

A total of 388 patients tested positive for any auto-ab (ANA 21.8%, ASMA 13.3%, AMA 2.2% and LKM 1.2%). Patients who tested positive versus negative were more likely to be women (29.3% vs 20.9%, p<0.001) and less likely to achieve SVR with most treated patients receiving interferon-based therapies (37.2% vs 47.1%, p=0.031). There was no difference between groups for baseline laboratory data, disease state or rate of extrahepatic manifestations (42.8% vs 45.0%, p=0.44). Kaplan-Meier analysis revealed no statistically significant difference between groups for the 10-year development of cirrhosis, hepatic decompensations, HCC nor survival. Furthermore, auto-ab positivity was only found to be a predictor for a lower rate of SVR on multivariate analysis (adjusted OR=1.61, 95 %  CI 1.00 to 2.58, p=0.048).

Conclusions

In our cohort, auto-ab positivity was common, especially in women, and predicted a lower rate of SVR but otherwise had no impact on the natural history of chronic HCV or presence of extrahepatic manifestations.

Anti-cyclic citrullinated peptide and rheumatoid factor in patients with chronic hepatitis B and hepatitis B carriers

OBJECTIVE

Rheumatoid factor (RF) positivity that may occur in a number of patients with hepatitis B (HBV) infection poses challenges in terms of differential diagnosis with rheumatoid arthritis (RA). On the other hand, antibodies to cyclic citrullinated peptide (anti-CCP) may prove to be an important marker for differential diagnosis of the two conditions. This study aimed to assess anti-CCP and RF positivity among patients with hepatitis B and rheumatoid arthritis.

MATERIAL AND METHODS

Anti-CCP and RF seropositivity was assessed in 61 patients with HBV infection (32 patients with chronic hepatitis, 29 patients with inactive HBV carrier status) and 40 patients with RA as the control group.

RESULTS

RF positivity was found in 18.7% and 34.4% of the patients with chronic hepatitis B and inactive HBV carrier status, respectively. On the other hand, only one patient with chronic HBV had low positive anti-CCP. RF was positive in 24 (60%) and anti-CCP was positive in 26 (65%) patients among the 40 patients with RA.

CONCLUSION

Anti-CCP may be helpful in the differential diagnosis between RA and chronic HBV infection or inactive HBV carrier status.

Autoantibody profile in individuals with chronic hepatitis C

INTRODUCTION

Autoantibodies are often produced during infection with chronic hepatitis C virus (HCV), but it remains controversial whether they influence the biochemical profile and histological features of this disease. Therefore, this current study sought to describe these autoantibodies and evaluate their impact on the clinical and histological presentation of hepatitis C.

METHODS

This cross-sectional analytical study assessed patients with HCV (RNA+) from October 2011 to July 2012.

RESULTS

This study included 66 patients, with a mean age of 53.2±10.5 years. Of these patients, 60.6% were male, and 54.3% presented with genotype 1. Non-organ-specific autoantibodies (NOSA) were detected in 24% of the patients; of these, 7.6% were anti-mitochondrial antibodies (AMA+), 26.7% were anti-smooth muscle antibodies (SMA+) and 6.8% were liver kidney microsomal type 1 antibodies (LKM1+). With respect to the thyroid autoantibodies, 7.4% were anti-peroxidase (ATPO+) antibodies, and none were anti-thyroglobulin (ATG+) antibodies. Regarding celiac disease autoantibodies, 5.8% were endomysial antibodies (EMA+), and no transglutaminase (TTG+) antibodies were detected. Cryoglobulins were found in 2.1% of patients. When NOSA+ individuals were compared to patients without the presence of NOSAs, they exhibited higher median alkaline phosphatase (0.7 vs. 0.6 xULN; p=0.041), lower median platelet counts (141,500.0 vs. 180,500.0/mm 3 ; p=0.036), lower mean prothrombin activity (72.6±11.5% vs. 82.2±16.0%; p=0.012) and an increased prevalence of significant fibrosis (E≥2) (45.5% vs. 18.2%; p=0.012). There was also a tendency for a greater proportion of NOSA+ cases to have marked periportal activity (APP≥3) (44.5% vs. 15.6%; p=0.087).

CONCLUSIONS

In addition to the high prevalence of autoantibodies associated with HCV infection, it was observed that NOSA positivity was associated with a more severe histological and biochemical profile of hepatitis C infection.

Autoantibodies in liver disease: important clues for the diagnosis, disease activity and prognosis

It has been well established that numerous kinds of autoantibodies have been detected in liver disease. Some kinds of autoantibodies may be helpful in the diagnosis of autoimmune liver diseases including autoimmune hepatitis, primary biliary cirrhosis or primary sclerosing cholangitis. However, these autoantibodies are present even in sera of patients with viral hepatitis, drug-induced hepatitis, alcoholic liver disease, non-alcoholic fatty liver disease and hepatocelluar carcinoma as well as in sera of patients with autoimmune liver diseases. Other kinds of autoantibodies are recognized as predictive hallmarks for disease activity or prognosis in liver diseases. On the other hand, treatment with interferon initiates the production of several types of autoantibodies in patients with chronic hepatitis C virus infection. Some of autoantibodies induced by interferon may postulate the treatment outcome in those patients. Recent studies also revealed the close correlation between oxidative stress and the production of autoantibodies in liver diseases. This article primarily reviews the recent advances of autoantibodies in the liver diseases and discusses the clinical significance of these autoantibodies.

Clinical significance of the detection of antinuclear antibodies in patients with acute hepatitis a

Background/Aims

The findings of several recent studies suggest that antinuclear antibodies (ANAs) are frequently detected in patients with acute hepatitis A (AHA). However, the clinical significance of a positive ANA test remains uncertain. This study was performed to evaluate the clinical significance of ANAs in AHA patients.

Methods

All patients admitted with AHA were consecutively enrolled in this study. An ANA assay was performed by indirect immunofluorescence during hospitalization. ANA positivity was defined as an ANA titer ≥1:80. The peak international normalized ratio (INR), peak alanine aminotransferase (ALT) and peak bilirubin levels were assessed over the duration of the hospitalization, and the incidence of AHA complications was evaluated.

Results

A total of 422 patients were enrolled in this study (age, 31±7 years), of which 260 (61.6%) were men. ANAs were detected in 179 AHA patients (42.4%). The proportion of ANA-positive patients varied significantly with AHA status on the day of the ANA assay (4.7% during the prodromal period vs 52.1% during the icteric or recovery period, p<0.001) and sex (56.2% in women vs 33.8% in men, p<0.001). The ANAs became undetectable in all ANA-positive patients within 3 months. The incidence of complications, including mortality, fulminant hepatic failure, renal dysfunction, relapse, and cholestatic hepatitis, did not differ significantly between ANA-positive and ANA-negative patients.

Conclusions

ANAs were detected frequently and transiently in patients with AHA, especially after their peak-ALT day. The presence of ANAs may not be associated with the clinical outcome of AHA, but simply with AHA status on the ANA assay day.

The initial manifestations and final diagnosis of patients with high and low titers of antinuclear antibodies after 6 months of follow-up

BACKGROUND

The antinuclear antibody (ANA) test is the most commonly used test to screen for autoimmune diseases. However, only a limited numbers of studies have addressed the characteristics of patients positive for ANA. In this study, we aimed to clarify the relationship between initial presentations, ANA titer, and final diagnoses.

METHODS

Patients who visited National Taiwan University Hospital and received a first ANA test were enrolled and then followed for a further 6 months. The symptoms and signs at the time of ANA testing, ANA titers, and the final diagnoses were recorded and analyzed.

RESULTS

A total of 355 patients were positive for ANA. Joint pain was the most common initial presentation at the time of ANA testing. Compared with the patients with low ANA titers (<1:640), those with high ANA titers (≥ 1:640) were more susceptible to autoimmune diseases. More importantly, of the patients with initial presentations of joint pain, fever, abnormal urinalysis, or skin rash/skin tightness, autoimmune diseases were more frequently diagnosed in those with high ANA titers than with low ANA titers (p<0.05). In addition, both anti-double strand DNA antibodies and anti-extractable nuclear antibodies were more commonly detected in patients with high ANA titers.

CONCLUSIONS

A high ANA titer seems to be a useful biomarker for the diagnosis of autoimmune diseases, especially for patients presenting with joint pain, fever, abnormal urinalysis, or skin rash/skin tightness.

Antinuclear antibody positivity in patients with chronic hepatitis C: clinically relevant or an epiphenomenon?

BACKGROUND

Serum autoantibodies such as antinuclear antibody (ANA) are frequently detected in patients with chronic hepatitis C virus (HCV) infection, but its relevance is a matter of discussion.

AIM

To assess the association of ANA positivity with clinical and histological features, and with the outcome of antiviral therapy in patients with HCV infection.

METHODS

Baseline samples from patients with hepatitis C treated with interferon and ribavirin were tested for ANA positivity by indirect immunofluorescence.

RESULTS

The mean age was 48.3+/-11.1 years and 56% were men. Among 234 included patients, 22 patients (9.4%) were positive for ANA. These patients showed significantly higher median alanine aminotransferase level (3.52 vs. 2.39 x upper limit of normal, P=0.009) when compared with ANA-negative patients. Fibrosis stage and necroinflammatory grading were not influenced by ANA positivity. Sustained virological response (SVR) rates were similar between ANA-positive and ANA-negative patients (27 vs. 29%, P=0.882). Alanine aminotransferase flares (> or = 1.5-fold the baseline) during treatment were observed in 28 patients (12%), irrespective of the presence of ANA and without any clinical significance.

CONCLUSION

Among HCV patients, ANA positivity seems to represent an immunological epiphenomenon. It neither influences clinical, biochemical, and histological features of chronic hepatitis C nor predicts response to antiviral treatment.

Clinical characteristics of patients with hepatitis C virus-related chronic liver disease seropositive for anticentromere antibody

The association between anticentromere antibody (ACA) and hepatitis C virus (HCV) infection remains unclear. We subjected eight patients with HCV-related chronic liver disease (CLD) seropositive for ACA to a battery of clinical and laboratory tests. The patient cohort was dominated by females, and four of the eight (50%) patients had a concomitant autoimmune disease. All of the patients had high titers of ACA (>or=1:320). The histological activity index scores in chronic hepatitis C (CH-C) patients with ACA were significantly higher than those in CH-C patients without antinuclear antibody (ANA) (12.8 +/- 1.8 vs. 8.3 +/- 4.5, P = 0.0372). The frequency of human leukocyte antigen (HLA) DR-8 in patients with HCV-related CLD seropositive for ACA was significantly higher than that in patients with CH-C seronegative for ANA (71 vs. 18%, P = 0.0108). These findings suggest that ACA is induced by chronic HCV infection in association with HLA DR-8, and that CH-C patients with ACA exhibit more severe hepatic fibrosis and inflammation than CH-C patients without ANA.

Serological markers of autoimmunity in patients infected with hepatitis C virus: impact of HIV co-infection

OBJECTIVES

We sought to evaluate the prevalence, predictors and significance of autoantibody expression in patients with chronic hepatitis C (CHC) with or without HIV co-infection.

METHODS

Retrospective review of laboratory and histologic data for all patients with CHC who had a liver biopsy available. HIV status was documented in all patients. Results analyzed in SPSS10, Chicago, IL, a p value <0.05 was considered significant.

RESULTS

170 patients with hepatitis C viremia, including 107 (63%) HIV co-infection, who had testing for anti-nuclear antibody (ANA) or anti-smooth muscle antibody (ASMA) and anti-mitochondrial antibody (AMA) were included in the study. Overall, 63% (74/117) of patients were ASMA seropositive and 6% (9/153) were positive for ANA. All 117 patients tested for AMA were negative. HIV co-infected patients were significantly more likely to be ASMA positive 71% (53/75) compared to those with hepatitis C alone (50%) [P=0.026]. There were no significant differences in age, gender, race, risk group, alanine aminotransferase (ALT) levels or grade of inflammation on histology between autoantibody positive and negative patients. ASMA positive patients had significantly higher globulin levels (P=0.036) and a trend towards more bridging fibrosis or cirrhosis. Patients with autoantibody expression rarely had histologic features of AIH.

CONCLUSION

We found a high rate of ASMA seropositivity in our cohort of patients with chronic hepatitis C, and HIV co-infection was associated with significantly higher rates of ASMA expression. Autoantibody expression was not associated with demographic or clinical characteristics and does not necessarily preclude antiviral therapy.

Management of hepatitis C virus-related arthritis

In recent years, hepatitis C virus-related arthritis (HCVrA) has been recognised as an autonomous rheumatic disorder. Two subsets of the disease have been identified: a polyarthritis involving small joints that resembles rheumatoid arthritis, but is usually milder, and a mono-oligoarthritis that shows an intermittent course and is frequently associated with the presence of cryo-globulins in serum. Few data about HCVrA treatment are reported in the literature. As a consequence, the therapeutic approach for this disorder is still largely empirical. Hydroxychloroquine, low doses of corticosteroids and NSAIDs are frequently administered to patients with HCVrA, but some authors describe an incomplete relief of symptoms, especially in the rheumatoid-like subset. Intake of low doses of corticosteroids and NSAIDs is more effective in subjects belonging to the mono-oligoarthritis group. Use of antiviral drugs (IFN plus ribavirin) shows good results, but IFN can induce or worsen autoimmune disorders. For this reason, in our opinion, this approach should be prescribed only when required by the coexistent liver disease. On the basis of the poor available data, the administration of anti-TNF-alpha agents seems safe in HCV patients, but the usually non-aggressive course of HCVrA does not justify their use as a current therapy.

Prevalence and significance of autoantibodies in patients with non-alcoholic steatohepatitis

GOALS

The aim of this study is to evaluate the prevalence and the clinical and histologic correlates of autoantibodies in patients with nonalcoholic steatohepatitis (NASH).

BACKGROUND

Antinuclear antibodies (ANA) and anti-smooth muscle antibodies (ASMA) have been identified in patients with NASH. The significance of autoantibodies in NASH is uncertain.

STUDY

Clinical data from patients with a histologic diagnosis of NASH at a university hospital in Chicago, Illinois between January 1999 and April 2003 were reviewed retrospectively. Seventy-four patients who were tested for autoantibodies and had no history of alcohol abuse or a systemic autoimmune disease were included. Demographic information and laboratory data were collected. Autoantibody titers > or = 1:40 were considered positive. A single pathologist reviewed all liver biopsies and scored features of NASH and identified characteristics of autoimmune hepatitis.

RESULTS

Thirty-four percent of patients with NASH had positive ANA titers and 6% were ASMA positive. Demographic and laboratory parameters did not differ by ANA status, except that women were more frequently ANA positive then men (P = 0.01). The severity of steatosis, inflammation, and fibrosis on liver biopsy were similar in the ANA positive and negative groups. Only 15% of ANA positive patients with NASH had a plasma cell infiltrate on liver biopsy and there was no difference in the frequency of histologic features of autoimmune hepatitis between ANA positive and negative patients.

CONCLUSIONS

Antinuclear antibodies are common in patients with NASH and most frequently represent a nonspecific antibody response that is not associated with the pattern or severity of injury on liver biopsy.

The presence of non-organ-specific autoantibodies is associated with a negative response to combination therapy with interferon and ribavirin for chronic hepatitis C

BACKGROUND

Non-organ-specific autoantibodies are found in a considerable number of anti-HCV positive patients. Previous studies investigated the clinical relevance of these antibodies in patients treated with interferon monotherapy, but not combination therapies.

METHODS

Anti-nuclear, anti-smooth muscle, anti-mitochondrial, anti-neutrophil-cytoplasmatic and anti-liver/kidney microsomal antibodies were determined in 78 consecutive anti-HCV positive patients by indirect immunofluorescence. The presence of these antibodies was related to demographic variables and to the outcome of antiviral combination therapy with interferon-alpha and ribavirin in 65 patients.

RESULTS

In our study, positivity for autoantibodies was associated with higher alanine aminotransferase levels and higher mean values for HCV-RNA (p < 0.01). Furthermore, negativity for non-organ-specific autoantibodies was associated with a favourable treatment outcome of combination therapy with at least one negative RT-PCR for HCV-RNA during treatment (OR 4.65, 95% CI 1.31 to 16.48, p = 0.02). ANA and SMA staining patterns and titers were not correlated to treatment response. With multiple logistic regression analysis, positivity for autoantibodies and HCV genotype were independently associated with outcome of antiviral combination therapy (p = 0.02).

CONCLUSIONS

The absence of non-organ-specific autoantibodies might indicate a significantly higher chance for viral clearance in response to combination therapy for chronic hepatitis C infection. Therefore, despite of an overall higher treatment response, the addition of the immunomodulatory drug ribavirin could accentuate immunological differences that affect treatment outcome and might have been less obvious in earlier studies analysing interferon monotherapy.