Abstract
AIM: Various side effects have been reported in patients infected with hepatitis C virus (HCV) who were treated with interferon-alpha (IFN-α), including the appearance or exacerbation of underlying autoimmune diseases and the development of a variety of organ and non-organ specific autoantibodies (NOSA). However, very few studies in adults have been strictly designed to address: whether the prevalence and the titre of organ and NOSA in serial samples of HCV-treated patients were affected by IFN-α, and the impact of these autoantibodies on the treatment outcome of HCV patients.
METHODS: We investigated whether parietal cell autoantibodies (PCA) and/or NOSA were related with treatment-outcome in 57 HCV-treated patients (19 sustained-responders, 16 relapsers, 22 non-responders). Serum samples from patients were studied blindly at three time-points (entry, end of treatment and end of followup). For the detection of autoantibodies we used indirect immunofluorescence, commercial and in-house ELISAs.
RESULTS: Sustained biochemical response was associated with ANA-negativity at the entry or end of follow up. Sustained virological response was associated with the absence of PCA at the entry. Combined virological and biochemical sustained response (CVBSR) was associated with the absence of antinuclear antibodies (ANA) at the end of follow up and PCA-negativity at the entry. Sustained virological and CVBSR were associated with a reduction of ANA and SMA titers during therapy.
CONCLUSION: Although PCA and/or NOSA seropositivity should not affect the decision to treat HCV patients, the presence of some of them such as ANA, PCA and SMA before treatment or their increase during therapy with IFN- α may predict a worse response, indicating the need for a closer monitoring during treatment of HCV patients positive for these autoantibodies.
Keywords: HCV infection, Autoantibodies, Interferon-alpha
INTRODUCTION
Hepatitis C virus (HCV) infection has been associated with several immune-mediated phenomena including autoimmune thyroiditis[1], Sjogren’s-like syndrome[2], essential mixed cryoglobulinemia[3], and autoantibody production[4-16].
Administration of interferon-alpha (IFN-α) in combination with ribavirin has already been proved to be the most promising therapeutic approach for the treatment of HCV infection[17-19]. Various side-effects have been reported in patients treated with this cytokine, including the appearance or exacerbation of underlying autoimmune diseases and the development of a variety of organ and non-organ specific autoantibodies (NOSA)[4-16,20-22]. However, very few studies in adults have been strictly designed to address: whether the prevalence and the titre of organ and NOSA in serial samples of HCV-treated patients were affected by IFN-α therapy, and the impact of these autoantibodies on the treatment outcome of HCV patients[6,23-28].
We conducted a retrospective serological study in order to evaluate at three time-points (entry, end of treatment, end of follow-up) whether parietal cell autoantibodies (PCA) and NOSA in HCV-treated patients were affected by the IFN-α treatment and furthermore, to address which was, if any, their impact on the treatment outcome. We report here our first results.
MATERIALS AND METHODS
Patients
Sera from 57 selected HCV patients, previously treated with a course of antiretroviral therapy, were studied. According to the aim of the study, serum samples were collected at three time-points: baseline, end of treatment and end of follow-up (6-12 mo after suspension of therapy). In order to address our hypothesis, these samples were selected from our records in an attempt to make three groups of HCV patients matched for age, sex, HCV-genotype and HCV viral load. The first group was consisted of 19 patients who achieved combined sustained virological and biochemical response (responders), the second of 16 who had relapsed after an initial response at the end of treatment (relapsers) and the third of 22 who had no response (non-responders). At the end of treatment, biochemical response was achieved in 46 patients (81%), virological response in 37 (65%) and combined biochemical and virological response in 35 (61%). At the end of follow up, sustained biochemical response was observed in 33 patients (58%), sustained virological response in 20 (35%) and combined sustained biochemical and virological response in 19 (33%).
Diagnosis of HCV infection was based on clinical, laboratory and histological evaluations as we described previously[9,11,29]. All patients had no clinical laboratory or histological signs of autoimmune hepatitis (revised score for the diagnosis of this disease was less than 10 in all of them)[30]. Twenty-seven patients were treated with IFN-α (3 MU three times weekly) and ribavirin (19 patients infected with genotype 1 or 4 and two patients with undetermined genotype received 1000-1200 mg ribavirin daily, while 6 patients with genotype 2 or 3 received 800 mg/d) for 48 wk. The remaining 30 patients received IFN-α only (3 MU three times weekly) for 24-48 wk. Patients were followed up at least for 18 mo from the beginning of treatment.
Patients were regularly seen in the outpatient clinic for physical examination, blood tests and virological assays. Serum samples of the patients were investigated at the three time-points for PCA and NOSA. A complete medical history, routine liver function tests, virological tests and histological evaluation were also available.
The end-of-treatment and end-of-follow-up responses were defined as the normalization of serum alanine aminotransferase level (ALT) at the end of treatment and follow-up period (biochemical response) and as the clearance of serum HCV-RNA by polymerase chain reaction (PCR) at the same time-points (virological response).
Histology
Liver biopsy specimens were available in 35 cases before the initiation of therapy. Nineteen HCV-infected patients with genotype 2 or 3 were excluded from biopsy, because of the favorable response to treatment and 3 patients were denied. The histological evaluation was assessed using the Knodell histologic/activity index score[31]. The inflammation score was obtained by combining the scores for the first three components of the Knodell index: portal, periportal and lobular inflammation (range 0-18). The Knodell fibrosis scores were: 0 (no fibrosis), 1 (portal fibrosis), 2 (portal fibrosis with few septa), 3 (bridging fibrosis) and 4 (cirrhosis)[31]. According to the previous publications of our group[29,32], patients were divided in to two groups according to inflammation: minimal/mild (0-8) and moderate/severe (9-18) and fibrosis none/mild/moderate (0-2) and severe fibrosis/cirrhosis (3-4).
Virologic tests
Serologic evidence of HCV infection was determined by the detection of antibodies to HCV (anti-HCV) using a third generation enzyme immunoassay (Murex Diagnostics, Temple Hill, Datford, UK). HCV-RNA levels were available in all patients using a commercially quantitative PCR (Cobas Amplicor HCV Monitor, Roche). HCV genotypes were determined by a reverse-hybridization method (InnoLipa HCV II, Innogenetics). Classification of genotypes was done according to Simmonds et al[33]. None of the patients studied was positive for hepatitis B surface antigen and antibodies to human immunodeficiency virus.
Detection of autoantibodies
Serum samples were tested for PCA and NOSA by two independent observers (N.G and G.D) blindly to the clinical status and the treatment outcome of the patients (double blind study).
Antinuclear antibodies (ANA) were detected by indirect immunofluorescence (IIF) on HEp-2 cells (INOVA Diagnostics) following standard protocols (positive titre ≥1:80), while smooth muscle antibodies (SMA), liver-kidney microsomal autoantibodies (anti-LKM), PCA, anti-mitochondrial antibodies (AMA) and antibodies against liver cytosol (anti-LC) were detected by IIF on rat liver, kidney and stomach sections as we described elsewhere[7,11,34]. Significant titers were considered ≥1:80 for SMA and ≥1:40 for anti-LKM, PCA and AMA. Anti-neutrophil cytoplasmic antibodies (ANCA) were detected by IIF on ethanol-fixed granulocytes (INOVA Diagnostics; positive titre ≥1:20). All ANCA-reactive samples by IIF were further investigated for the presence of IgG antibodies against proteinase 3 (anti-PR3, INOVA Diagnostics) and myeloperoxidase (anti-MPO, INOVA Diagnostics).
All samples were investigated for the presence of IgG antibodies against double stranded DNA (anti-dsDNA) and IgG anticardiolipin antibodies (anti-CL) using in-house ELISAs following published protocols by us[4,9,10,29,35]. The specificity, reproducibility and optimal conditions of these assays were determined in extensive preliminary experiments as described[4,9,10,29,35]. In each assay, the between-day variation of the optical density (A) values was eliminated by running serial dilutions of a positive control (standard curve) on each plate. Briefly, a standard curve was constructed by assaying repeatedly control sera positive for IgG anti-dsDNA and IgG anti-CL in serial dilutions (1:50 to 1:6400). The A value of the 1:6400 dilution was arbitrarily chosen as 1 binding unit (BU). The BU values for the test samples were calculated according to this curve. This was accomplished by dividing the A of each sample by the A value, which corresponded to 1BU for that plate. Finally, the results were expressed as binding index (BI) calculated by dividing the BU of every sample by the mean BU of the healthy controls plus 4SD, multiplied by 100. According to this formula, a BI of 100 was defined as the cut-off point of the assays. The adoption of this stringent cut-off point precluded the possibility of false-positive results[4,9,10,29,35].
All subjects consented to participate in the study at the time of interview. The Ethis Committee of Larissa University Hospital approved the study protocol.
Statistical analysis
Associations between the presence or absence of autoantibodies and different variables were assessed using the univariate unadjusted χ2 statistic. Statistical comparisons between means were calculated by one-way analysis of variance.
RESULTS
Demographic, epidemiologic, clinical, virologic and histologic characteristics of the patients at baseline are shown in Table 1. The duration of HCV disease was considered the period from the first time of iv drug abuse in iv drug abusers, while in the remaining HCV patients the duration was calculated from the first time of anti-HCV detection. No significant correlation was found between treatment outcome and sex, risk factors for contracting HCV and HCV-viral load. Patients below 45 years old had significantly increased virological (P = 0.006) and combined virological and biochemical response rates at the end of follow up (P = 0.01), while the presence of genotypes other than 1b or 4 was correlated with a significantly higher virological response rate at the end of treatment (P<0.03). In addition, none of the patients with severe fibrosis or cirrhosis achieved sustained biochemical and virological responses (P<0.05).
Table 1.
Non-responders (n = 22) | Relapsers (n = 16) | Sustained responders (n = 19) | |
Sex (M/F) | 15/7 | 10/6 | 13/6 |
Age (Mean/range) | 48±15 | 50±10 | 37±13 |
Disease duration (yr) | 2.4±2.1 | 2.9±3 | 2.5±2.4 |
Source of HCV Infection | |||
Transfusion before 1990 | 8 | 4 | 4 |
Iv drug abuse | 3 | 3 | 6 |
Multiple hospitalizations | 3 | 0 | 0 |
Multiple sexual partners | 0 | 1 | 2 |
Unknown | 8 | 8 | 7 |
Genotype | |||
1a/1b | 11 | 8 | 8 |
2a/c | 2 | 2 | 0 |
3a | 4 | 4 | 7 |
4 | 4 | 1 | 2 |
Undefined | 1 | 1 | 2 |
Viral load | |||
>2.106 copies/mL | 9 | 10 | 10 |
≤2.106 copies/mL | 13 | 6 | 9 |
Histologic data (Yes/No) | 14/8 | 11/5 | 10/9 |
Minimal/mild inflammation | 12 | 6 | 9 |
Moderate/severe inflammation | 2 | 5 | 1 |
None/mild/moderate fibrosis | 10 | 5 | 10 |
Severe fibrosis or cirrhosis | 4 | 6 | 0 |
HBV and/or HIV co-infection | 0 | 0 | 0 |
The prevalence of PCA and NOSA in HCV patients studied at the three time-points is shown in Table 2. There was no significant difference between the mean titers and autoantibodies detected at the three different time-points (Table 2). The prevalence of autoantibodies was not associated with the treatment schedule, which was administered to the patients (IFN-α with or without ribavirin; data not shown). Before treatment, the most frequent autoantibody detected was SMA (51/57; 89.5%), while ANA were found in 54.4%. Age over 45 years was significantly associated with ANA positivity at the end of treatment (22/26 patients over 45 years old vs 18/31 patients under 45 years old, P<0.05).
Table 2.
Before treatment (n = 57) |
End of treatment (n = 57) |
End of follow up (n = 57) |
P value | ||||
Pos (%) | Mean titre | Pos (%) | Mean titre | Pos (%) | Mean titre | ||
ANA | 54.4 | 1/188 | 70.2 | 1/194 | 71.9 | 1/171 | NS |
SMA | 89.5 | 1/127 | 89.5 | 1/135 | 84.2 | 1/118 | NS |
Undefined | 12.3 | 1/108 | 19.31 | 1/76 | 14 | 1/248 | NS |
cytoplasmic staining1 | |||||||
AMA | 0 | 0 | 0 | ||||
Anti-LKM | 5.3 | 1/133 | 7 | 1/100 | 5.3 | 1/67 | NS |
PCA | 15.8 | 1/76 | 17.5 | 1/108 | 15.8 | 1/231 | NS |
Anti-LC | 1.8 | 1/40 | 3.5 | 1/60 | 0 | NS | |
ANCA | 80.7 | 1/31 | 80.7 | 1/31 | 82.5 | 1/31 | NS |
CANCA | 78.9 | 1/28 | 77.2 | 1/30 | 77.2 | 1/28 | NS |
PANCA | 3.5 | 1/90 | 5.3 | 1/53 | 8.8 | 1/64 | NS |
Anti-PR-3 | 0 | 0 | 0 | ||||
Anti-MPO | 0 | 0 | 0 | ||||
Anti-dsDNA | 22.8 | 129 BI | 24.6 | 135 BI | 21.1 | 134 BI | NS |
Anti-CL | 19.3 | 148 BI | 29.8 | 138 BI | 17.5 | 129 BI | NS |
Abbreviations are same as in the text. pANCA = ANCA with perinuclear pattern, NS = not statistically significant, n = the number of individuals studied in each group. P values were calculated by one-way analysis of variance for the mean titres and by total χ2 for autoantibodies positivity.
Means an AMA-like pattern by indirect immunofluorescense on HEp-2 cells, which did not give an AMA pattern on frozen liver, renal and stomach sections and which did not react in specific ELISA for AMA and immunoblots on human liver.
ANCA were detected commonly in HCV-infected patients (80.7-82.5%). In most cases a diffuse cytoplasmic pattern (cANCA) was recorded. However, due to the absence of anti-PR3 and anti-MPO by ELISAs in all ANCA-positive samples, we considered them as ANCA-negative and they were excluded from further statistical analysis.
In overall, anti-LKM were detected in 4 out of 57 patients (7%) (Tables 2 and 3). The only anti-LKM-positive patient who had a sustained biochemical and virological response was that with the highest titer at the entry, which then decreased (end of treatment) and disappeared at the end of follow up (Table 3).
Table 3.
Gender | Genotype |
Anti-LKM titre |
Response |
|||
1st | 2nd | 3rd | End of treatment | End of follow-up | ||
M | 1b | 1/320 | 1/40 | 0 | Responder | Sustained responder |
F | 1b | 1/40 | 1/160 | 1/80 | Responder | Relapser |
F | 2a/c | 1/40 | 1/40 | 1/40 | Non-responder | Non-responder |
M | 4 | 0 | 1/160 | 1/80 | Non-responder | Non-responder |
Abbreviations are same as in the text. M = male, F = female, 1st, 2nd and 3rd refers to the sample obtained at the entry, at the end of treatment and at the end of follow-up, respectively.
The statistically significant correlations between the presence of PCA and/or NOSA and the response to treatment are shown in Tables 4A-C. The presence of ANA at the entry and at the end of follow up was significantly associated with the reduced rates of sustained biochemical response (Table 4). A combined sustained biochemical and virological response was achieved in a significantly higher proportion of ANA negative patients at the end of follow-up compared to those with ANA reactivity at the same chronic period (Table 5). None of the PCA-positive patients at the entry achieved a sustained virological or sustained biochemical and virological response (Tables 5 and 6).
Table 4.
Biochemical response at the end of follow up [n (%)] |
||||
n | Yes | No | P | |
ANA entry | ||||
Pos | 31 | 13 (41.9) | 18 (58.1) | 0.017 |
Neg | 26 | 20 (76.9) | 6 (23.1) | |
ANA end of follow up | ||||
Pos | 41 | 20 (48.8) | 21 (51.2) | 0.037 |
Neg | 16 | 13 (81.3) | 3 (18.7) |
Abbreviations are same as in the text. n = the number of individuals in each group, P values were calculated by Fischer’s exact test or χ2 where applicable.
Table 5.
Combined sustained response at the end of follow up [n (%)] |
||||
n | Yes | No | P | |
PCA entry | ||||
Pos | 9 | 0 (0) | 9 (100) | 0.022 |
Neg | 48 | 19 (39.6) | 29 (60.4) | |
ANA end of follow up | ||||
Pos | 41 | 10 (24.4) | 31 (75.6) | 0.048 |
Neg | 16 | 9 (56.3) | 7 (43.7) |
Abbreviations are same as in the text. n = the number of individuals in each group, P values were calculated by Fischer’s exact test or χ2 where applicable.
Table 6.
Virological response at the end of follow up [n (%)] |
||||
n | Yes | No | P | |
PCA entry | ||||
Pos | 9 | 0 (0) | 9 (100) | 0.02 |
Neg | 48 | 20 (41.7) | 28 (58.3) |
Abbreviations are same as in the text. n = the number of individuals in each group, P values were calculated by Fischer’s exact test or χ2 where applicable.
The treatment outcome was associated with alterations of the titres in some NOSA during the three time-points of investigation (Tables 7, 8 and 9). The decrease of ANA titers was associated with a significantly higher proportion of patients with sustained virological (P = 0.02) and combined sustained responses (P = 0.02) (Tables 7 and 8). The decrease of SMA titers was correlated with a significantly increased rate of sustained biochemical (P = 0.005), sustained virological (P = 0.003) and combined biochemical and virological responses (P = 0.001) (Tables 7, 8 and 9).
Table 7.
Virological response at the end of follow up [n (%)] |
||||
n | Yes | No | P | |
Alteration of ANA titres | ||||
Increase | 20 | 8 (40) | 12 (60) | 0.02 |
Decrease | 13 | 8 (61.5) | 5 (38.5) | |
Constant | 24 | 4 (16.7) | 20 (83.3) | |
Alteration of SMA titres | ||||
Increase | 14 | 3 (21.4) | 11 (78.6) | 0.003 |
Decrease | 18 | 12 (66.7) | 6 (33.3) | |
Constant | 25 | 5 (20) | 20 (80) |
Abbreviations are same as in the text. n = the number of individuals in each group of patients. Alterations of autoantibodies titres are referred to the period from entry to end of follow-up. P values were calculated by total χ2.
Table 8.
Combined sustained response at the end of follow up [n (%)] |
||||
n | Yes | No | P | |
Alteration of ANA titers | ||||
Increase | 20 | 7 (35) | 13 (35) | 0.02 |
Decrease | 13 | 8 (61.5) | 5 (38.5) | |
Constant | 24 | 4 (16.7) | 20 (83.3) | |
Alteration of SMA titers | ||||
Increase | 14 | 2 (14.3) | 12 (85.7) | 0.001 |
Decrease | 18 | 12 (66.7) | 6 (33.3) | |
Constant | 25 | 5 (20) | 20 (80) |
Abbreviations are same as in the text. n = the number of individuals in each group of patients. Alterations of autoantibodies titres are referred to the period from entry to end of follow up. P values were calculated by total χ2.
Table 9.
Biochemical response at the end of follow up [n (%)] |
||||
n | Yes | No | P | |
Alteration of SMA titers | ||||
Increase | 14 | 7 (50) | 7 (50) | 0.005 |
Decrease | 18 | 16 (88.8) | 2 (11.2) | |
Constant | 25 | 10 (40) | 15 (60) |
Abbreviations are same as in the text. n = the number of individuals in each group of patients. Alterations of autoantibodies titres are referred to the period from entry to end of follow-up. P values were calculated by total χ2.
DISCUSSION
We demonstrated that the majority of HCV patients had circulating NOSA while a significant proportion had also PCA. Several organ and NOSA has already been associated with HCV infection both in adults and children[4-16,22-28]. So far however, very few studies have been strictly designed to investigate the alterations of these autoantibodies and their impact on the treatment outcome after a course of IFN-α[6,23-28]. In addition, some of the previous data regarding the variation and influence of NOSA on the response to IFN-α were referred to the childhood[6,25] and not to the adult population.
Our study confirmed that PCA and NOSA were frequently detected in HCV patients. Similarly to previous reports by Gregorio et al[6,36], these autoantibodies appeared to be a part of the natural course of chronic hepatitis C, since their prevalence and titre were unaffected by IFN-α. In contrast, Agarwal et al[26] showed a disappearance of PCA and NOSA during treatment with IFN-α, but in this study a relatively small number of patients were followed up (7 patients only).
Interestingly however, we found that the presence and the titre alterations in some of these autoantibodies during the follow-up period had an effect on the treatment response. In particular, the presence of ANA at the entry and the end of follow up, as well as the detection of PCA at the entry were correlated with a worse response. Additionally, the decrease of ANA and SMA titres from the entry to the end of follow up was associated with a better outcome after IFN-α therapy. Our findings are in accordance with only two very recent studies by Muratori et al[25] and Wasmuth et al[28], which investigated the impact of NOSA on IFN-α with or without combination with ribavirin treatment in HCV-infected children and adults. However, other studies have shown no relation of organ and NOSA with response to treatment[6,23,24,27,37,38].
Apart from treatment outcome, the clinical significance of PCA and NOSA in our series of patients remains obscure. Among several autoantibodies investigated, only ANA were associated with older ages, which is in agreement with the findings of Squadrito et al[14], but in contrast with other studies[22,39]. In addition, similarly with a recent study by Stroffolini et al[39], we were not able to show any correlation between the positivity of autoantibodies and liver damage. In contrast, other reports supported that continuous hepatocellular damage due to HCV might be an essential step for the production of autoantibodies[8,13,38]. Under this context and in view of the growing evidence for molecular mimicry as a mechanism of autoimmunity, a recent elegant study by Gregorio et al[40] has shown that ANA and SMA in chronic HCV-infection may arise as a consequence of cross-reactive immune responses to HCV and host smooth muscle/nuclear antigens. The latter speculation could support, at least in part, our findings where a favorable biochemical and virological response was associated with a decline of ANA and SMA titres (the lower the viral load, the lower the cross-reactive immune response with host antigens).
We were not able to show any significant alterations of PCA during therapy, which is in contrast with recent observations by Fabbri et al[15]. These researchers demonstrated a statistically significant increase of patients positive for PCA during IFN-α treatment, which was associated with the development of autoimmune gastritis and autoimmune thyroiditis[15]. ANCA were considered to be negative because we did not find reactivity against MPO or PR-3 by specific ELISAs. This finding is similar with that reported previously by our group[41] and others[42]. However, a recent study in HCV patients by Wu et al[12] reported a high prevalence of cANCA by identifying PR-3 as their major target autoantigen.
The prevalence of anti-LKM in our patients is comparable with previous works from our group and others[5,6,8,11,24,25]. Only one of our HCV+/anti-LKM+ patients succeeded a sustained response. Interestingly, this patient had the highest titre at the entry among the anti-LKM positive patients and was infected with genotype 1b. Nevertheless, the progressive decline of anti-LKM titre up to disappearance at the end of follow up was associated with a combined sustained biochemical and virological response. The disappearance of this antibody in combination with the disappearance of the virus further supports the concept that anti-LKM production in HCV infection may be at least in part, the result of a cross-reactive immune response between the virus and cytochrome P4502D6 (CYP2D6)[7,43]. Additional supports to this hypothesis emerged from recent studies by Kerkar et al[44] and Bogdanos et al[45]. In the first study the authors were able to show cross-reactivity between the immunodominant epitope 193-212 of CYP2D6 and homologies of two unrelated viruses (HCV 2977-2996 and CMV 121-140)[44]. In the second study the investigators for the first time gave experimental support to the notion that molecular similarities between CYP2D6, HCV and herpes simplex virus could result in anti-LKM production via a cross-reactive response[45].
Although occasionally IFN-α might unmask or provoke autoimmune hepatic reactions and even “true” autoimmune hepatitis in HCV-treated patients[7,24,30,37], the response rate to IFN-α was in general the same both in anti-LKM-positive and anti-LKM-negative HCV patients. This was also the case in our patients.
In conclusion, PCA and NOSA, including anti-LKM, are commonly found in adult HCV patients. Although seropositivity for these autoantibodies should not affect the decision to treat HCV patients, the presence of some of them such as ANA, PCA and SMA before treatment or their increase during IFN-α therapy may predict a worse response, suggesting the need for a more intensive follow up during treatment of HCV patients positive for these autoantibodies. Two very recent studies, one in children and the other in adult population with hepatitis C, could enhance our findings since both of them have demonstrated a lower benefit from IFN-α therapy among NOSA-positive/HCV-positive subjects[25,28]. Future prospective studies are needed to uncover the full spectrum of these associations and to provide new insights into their operating mechanisms.
Footnotes
Edited by Wang XL
References
- 1.Tsianos EV, Dalekos GN, Merkouropoulos MH, Tsatsoulis A, Seferiadis KI. Frequency of thyroid dysfunction after recombinant alpha-interferon therapy in Greek patients with chronic active hepatitis. Eur J Gastroenterol Hepatol. 1994;6:547–551. [Google Scholar]
- 2.Fox RI, Stern M, Michelson P. Update in Sjögren syndrome. Curr Opin Rheumatol. 2000;12:391–398. doi: 10.1097/00002281-200009000-00007. [DOI] [PubMed] [Google Scholar]
- 3.Christodoulou DK, Dalekos GN, Merkouropoulos MH, Kistis KG, Georgitsi G, Zervou E, Zachou K, Tsianos EV. Cryoglobulinemia due to chronic viral hepatitis infections is not a major problem in clinical practice. Eur J Intern Med. 2001;12:435–441. doi: 10.1016/s0953-6205(01)00151-0. [DOI] [PubMed] [Google Scholar]
- 4.Dalekos GN, Manoussakis MN, Zervou E, Tsianos EV, Moutsopoulos HM. Immunologic and viral markers in the circulation of anti-HIV negative heroin addicts. Eur J Clin Invest. 1993;23:219–225. doi: 10.1111/j.1365-2362.1993.tb00765.x. [DOI] [PubMed] [Google Scholar]
- 5.Bortolotti F, Vajro P, Balli F, Giacchino R, Crivellaro C, Barbera C, Cataleta M, Muratori L, Pontisso P, Nebbia G, et al. Non-organ specific autoantibodies in children with chronic hepatitis C. J Hepatol. 1996;25:614–620. doi: 10.1016/s0168-8278(96)80228-5. [DOI] [PubMed] [Google Scholar]
- 6.Gregorio GV, Pensati P, Iorio R, Vegnente A, Mieli-Vergani G, Vergani D. Autoantibody prevalence in children with liver disease due to chronic hepatitis C virus (HCV) infection. Clin Exp Immunol. 1998;112:471–476. doi: 10.1046/j.1365-2249.1998.00574.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 7.Dalekos GN, Wedemeyer H, Obermayer-Straub P, Kayser A, Barut A, Frank H, Manns MP. Epitope mapping of cytochrome P4502D6 autoantigen in patients with chronic hepatitis C during alpha-interferon treatment. J Hepatol. 1999;30:366–375. doi: 10.1016/s0168-8278(99)80092-0. [DOI] [PubMed] [Google Scholar]
- 8.Lenzi M, Bellentani S, Saccoccio G, Muratori P, Masutti F, Muratori L, Cassani F, Bianchi FB, Tiribelli C. Prevalence of non-organ-specific autoantibodies and chronic liver disease in the general population: a nested case-control study of the Dionysos cohort. Gut. 1999;45:435–441. doi: 10.1136/gut.45.3.435. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 9.Dalekos GN, Kistis KG, Boumba DS, Voulgari P, Zervou EK, Drosos AA, Tsianos EV. Increased incidence of anti-cardiolipin antibodies in patients with hepatitis C is not associated with aetiopathogenetic link to anti-phospholipid syndrome. Eur J Gastroenterol Hepatol. 2000;12:67–74. doi: 10.1097/00042737-200012010-00013. [DOI] [PubMed] [Google Scholar]
- 10.Dalekos GN, Zachou K, Liaskos C. The antiphospholipid syndrome and infection. Curr Rheumatol Rep. 2001;3:277–285. doi: 10.1007/s11926-001-0031-4. [DOI] [PubMed] [Google Scholar]
- 11.Dalekos GN, Makri E, Loges S, Obermayer-Straub P, Zachou K, Tsikrikas T, Schmidt E, Papadamou G, Manns MP. Increased incidence of anti-LKM autoantibodies in a consecutive cohort of hepatitis C patients from central Greece. Eur J Gastroenterol Hepatol. 2002;14:35–42. doi: 10.1097/00042737-200201000-00007. [DOI] [PubMed] [Google Scholar]
- 12.Wu YY, Hsu TC, Chen TY, Liu TC, Liu GY, Lee YJ, Tsay GJ. Proteinase 3 and dihydrolipoamide dehydrogenase (E3) are major autoantigens in hepatitis C virus (HCV) infection. Clin Exp Immunol. 2002;128:347–352. doi: 10.1046/j.1365-2249.2002.01827.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 13.Muratori P, Muratori L, Stroffolini T, Pappas G, Terlizzi P, Ferrari R, Loffreda S, Cassani F, Rapicetta M, Guadagnino V, et al. Prevalence of non-organ specific autoantibodies in HCV-infected subjects in the general population. Clin Exp Immunol. 2003;131:118–121. doi: 10.1046/j.1365-2249.2003.02030.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 14.Squadrito G, Previti M, Lenzi M, Le Rose EP, Caccamo G, Restuccia T, Di Cesare E, Pollicino T, Raimondo G. High prevalence of non-organ-specific autoantibodies in hepatitis C virus-infected cirrhotic patients from southern Italy. Dig Dis Sci. 2003;48:349–353. doi: 10.1023/a:1021991813586. [DOI] [PubMed] [Google Scholar]
- 15.Fabbri C, Jaboli MF, Giovanelli S, Azzaroli F, Pezzoli A, Accogli E, Liva S, Nigro G, Miracolo A, Festi D, et al. Gastric autoimmune disorders in patients with chronic hepatitis C before, during and after interferon-alpha therapy. World J Gastroenterol. 2003;9:1487–1490. doi: 10.3748/wjg.v9.i7.1487. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 16.Cacoub P, Renou C, Rosenthal E, Cohen P, Loury I, Loustaud-Ratti V, Yamamoto AM, Camproux AC, Hausfater P, Musset L, et al. Extrahepatic manifestations associated with hepatitis C virus infection. A prospective multicenter study of 321 patients. The GERMIVIC. Groupe d'Etude et de Recherche en Medecine Interne et Maladies Infectieuses sur le Virus de l'Hepatite C. Medicine (Baltimore) 2000;79:47–56. doi: 10.1097/00005792-200001000-00005. [DOI] [PubMed] [Google Scholar]
- 17.McHutchison JG, Gordon SC, Schiff ER, Shiffman ML, Lee WM, Rustgi VK, Goodman ZD, Ling MH, Cort S, Albrecht JK. Interferon alfa-2b alone or in combination with ribavirin as initial treatment for chronic hepatitis C. Hepatitis Interventional Therapy Group. N Engl J Med. 1998;339:1485–1492. doi: 10.1056/NEJM199811193392101. [DOI] [PubMed] [Google Scholar]
- 18.Manns MP, McHutchison JG, Gordon SC, Rustgi VK, Shiffman M, Reindollar R, Goodman ZD, Koury K, Ling M, Albrecht JK. Peginterferon alfa-2b plus ribavirin compared with interferon alfa-2b plus ribavirin for initial treatment of chronic hepatitis C: a randomised trial. Lancet. 2001;358:958–965. doi: 10.1016/s0140-6736(01)06102-5. [DOI] [PubMed] [Google Scholar]
- 19.Fried MW, Shiffman ML, Reddy KR, Smith C, Marinos G, Gonçales FL, Häussinger D, Diago M, Carosi G, Dhumeaux D, et al. Peginterferon alfa-2a plus ribavirin for chronic hepatitis C virus infection. N Engl J Med. 2002;347:975–982. doi: 10.1056/NEJMoa020047. [DOI] [PubMed] [Google Scholar]
- 20.Fattovich G, Giustina G, Favarato S, Ruol A. A survey of adverse events in 11,241 patients with chronic viral hepatitis treated with alfa interferon. J Hepatol. 1996;24:38–47. doi: 10.1016/s0168-8278(96)80184-x. [DOI] [PubMed] [Google Scholar]
- 21.Dalekos GN, Christodoulou D, Kistis KG, Zervou EK, Hatzis J, Tsianos EV. A prospective evaluation of dermatological side-effects during alpha-interferon therapy for chronic viral hepatitis. Eur J Gastroenterol Hepatol. 1998;10:933–939. doi: 10.1097/00042737-199811000-00006. [DOI] [PubMed] [Google Scholar]
- 22.Clifford BD, Donahue D, Smith L, Cable E, Luttig B, Manns M, Bonkovsky HL. High prevalence of serological markers of autoimmunity in patients with chronic hepatitis C. Hepatology. 1995;21:613–619. [PubMed] [Google Scholar]
- 23.Noda K, Enomoto N, Arai K, Masuda E, Yamada Y, Suzuki K, Tanaka M, Yoshihara H. Induction of antinuclear antibody after interferon therapy in patients with type-C chronic hepatitis: its relation to the efficacy of therapy. Scand J Gastroenterol. 1996;31:716–722. doi: 10.3109/00365529609009156. [DOI] [PubMed] [Google Scholar]
- 24.Cassani F, Cataleta M, Valentini P, Muratori P, Giostra F, Francesconi R, Muratori L, Lenzi M, Bianchi G, Zauli D, et al. Serum autoantibodies in chronic hepatitis C: comparison with autoimmune hepatitis and impact on the disease profile. Hepatology. 1997;26:561–566. doi: 10.1002/hep.510260305. [DOI] [PubMed] [Google Scholar]
- 25.Muratori P, Muratori L, Verucchi G, Attard L, Bianchi FB, Lenzi M. Non-organ-specific autoantibodies in children with chronic hepatitis C: clinical significance and impact on interferon treatment. Clin Infect Dis. 2003;37:1320–1326. doi: 10.1086/379018. [DOI] [PubMed] [Google Scholar]
- 26.Agarwal N, Handa R, Acharya SK, Wali JP, Dinda AK, Aggarwal P. A study of autoimmune markers in hepatitis C infection. Indian J Med Res. 2001;113:170–174. [PubMed] [Google Scholar]
- 27.Wada M, Kang KB, Kinugasa A, Shintani S, Sawada K, Nishigami T, Shimoyama T. Does the presence of serum autoantibodies influence the responsiveness to interferon-alpha 2a treatment in chronic hepatitis C? Intern Med. 1997;36:248–254. doi: 10.2169/internalmedicine.36.248. [DOI] [PubMed] [Google Scholar]
- 28.Wasmuth HE, Stolte C, Geier A, Dietrich CG, Gartung C, Lorenzen J, Matern S, Lammert F. The presence of non-organ-specific autoantibodies is associated with a negative response to combination therapy with interferon and ribavirin for chronic hepatitis C. BMC Infect Dis. 2004;4:4. doi: 10.1186/1471-2334-4-4. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 29.Zachou K, Liaskos C, Christodoulou DK, Kardasi M, Papadamou G, Gatselis N, Georgiadou SP, Tsianos EV, Dalekos GN. Anti-cardiolipin antibodies in patients with chronic viral hepatitis are independent of beta2-glycoprotein I cofactor or features of antiphospholipid syndrome. Eur J Clin Invest. 2003;33:161–168. doi: 10.1046/j.1365-2362.2003.01110.x. [DOI] [PubMed] [Google Scholar]
- 30.Alvarez F, Berg PA, Bianchi FB, Bianchi L, Burroughs AK, Cancado EL, Chapman RW, Cooksley WG, Czaja AJ, Desmet VJ, et al. International Autoimmune Hepatitis Group Report: review of criteria for diagnosis of autoimmune hepatitis. J Hepatol. 1999;31:929–938. doi: 10.1016/s0168-8278(99)80297-9. [DOI] [PubMed] [Google Scholar]
- 31.Knodell RG, Ishak KG, Black WC, Chen TS, Craig R, Kaplowitz N, Kiernan TW, Wollman J. Formulation and application of a numerical scoring system for assessing histological activity in asymptomatic chronic active hepatitis. Hepatology. 1981;1:431–435. doi: 10.1002/hep.1840010511. [DOI] [PubMed] [Google Scholar]
- 32.Georgiadou SP, Zachou K, Rigopoulou E, Liaskos C, Mina P, Gerovasilis F, Makri E, Dalekos GN. Occult hepatitis B virus infection in Greek patients with chronic hepatitis C and in patients with diverse nonviral hepatic diseases. J Viral Hepat. 2004;11:358–365. doi: 10.1111/j.1365-2893.2004.00513.x. [DOI] [PubMed] [Google Scholar]
- 33.Simmonds P, McOmish F, Yap PL, Chan SW, Lin CK, Dusheiko G, Saeed AA, Holmes EC. Sequence variability in the 5' non-coding region of hepatitis C virus: identification of a new virus type and restrictions on sequence diversity. J Gen Virol. 1993;74(Pt 4):661–668. doi: 10.1099/0022-1317-74-4-661. [DOI] [PubMed] [Google Scholar]
- 34.Dalekos GN, Obermayer-Straub P, Bartels M, Maeda T, Kayser A, Braun S, Loges S, Schmidt E, Gershwin ME, Manns MP. Cytochrome P450 2A6: a new hepatic autoantigen in patients with chronic hepatitis C virus infection. J Hepatol. 2003;39:800–806. doi: 10.1016/s0168-8278(03)00356-8. [DOI] [PubMed] [Google Scholar]
- 35.Dalekos GN, Manoussakis MN, Goussia AC, Tsianos EV, Moutsopoulos HM. Soluble interleukin-2 receptors, antineutrophil cytoplasmic antibodies, and other autoantibodies in patients with ulcerative colitis. Gut. 1993;34:658–664. doi: 10.1136/gut.34.5.658. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 36.Gregorio GV, Jones H, Choudhuri K, Vegnente A, Bortolotti F, Mieli-Vergani G, Vergani D. Autoantibody prevalence in chronic hepatitis B virus infection: effect in interferon alfa. Hepatology. 1996;24:520–523. doi: 10.1002/hep.510240309. [DOI] [PubMed] [Google Scholar]
- 37.Todros L, Saracco G, Durazzo M, Abate ML, Touscoz G, Scaglione L, Verme G, Rizzetto M. Efficacy and safety of interferon alfa therapy in chronic hepatitis C with autoantibodies to liver-kidney microsomes. Hepatology. 1995;22:1374–1378. [PubMed] [Google Scholar]
- 38.Massard J, Johanet C, Bedossa P, Poynard T, Buffet C, Di Martino V. Impact of hepatitis C-associated autoantibodies (AAbs) on the liver pathology and the response to antiviral therapy [abstract] J Hepatol. 2003;38(Suppl 2):155. [Google Scholar]
- 39.Stroffolini T, Colloredo G, Gaeta GB, Sonzogni A, Angeletti S, Marignani M, Pasquale G, Venezia G, Craxì A, Almasio P. Does an 'autoimmune' profile affect the clinical profile of chronic hepatitis C? An Italian multicentre survey. J Viral Hepat. 2004;11:257–262. doi: 10.1111/j.1365-2893.2004.00489.x. [DOI] [PubMed] [Google Scholar]
- 40.Gregorio GV, Choudhuri K, Ma Y, Pensati P, Iorio R, Grant P, Garson J, Bogdanos DP, Vegnente A, Mieli-Vergani G, et al. Mimicry between the hepatitis C virus polyprotein and antigenic targets of nuclear and smooth muscle antibodies in chronic hepatitis C virus infection. Clin Exp Immunol. 2003;133:404–413. doi: 10.1046/j.1365-2249.2003.02229.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 41.Dalekos GN, Tsianos EV. Anti-neutrophil antibodies in chronic viral hepatitis. J Hepatol. 1994;20:561. doi: 10.1016/s0168-8278(05)80508-2. [DOI] [PubMed] [Google Scholar]
- 42.Roozendaal C, de Jong MA, van den Berg AP, van Wijk RT, Limburg PC, Kallenberg CG. Clinical significance of anti-neutrophil cytoplasmic antibodies (ANCA) in autoimmune liver diseases. J Hepatol. 2000;32:734–741. doi: 10.1016/s0168-8278(00)80241-x. [DOI] [PubMed] [Google Scholar]
- 43.Muratori L, Parola M, Ripalti A, Robino G, Muratori P, Bellomo G, Carini R, Lenzi M, Landini MP, Albano E, et al. Liver/kidney microsomal antibody type 1 targets CYP2D6 on hepatocyte plasma membrane. Gut. 2000;46:553–561. doi: 10.1136/gut.46.4.553. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 44.Kerkar N, Choudhuri K, Ma Y, Mahmoud A, Bogdanos DP, Muratori L, Bianchi F, Williams R, Mieli-Vergani G, Vergani D. Cytochrome P4502D6(193-212): a new immunodominant epitope and target of virus/self cross-reactivity in liver kidney microsomal autoantibody type 1-positive liver disease. J Immunol. 2003;170:1481–1489. doi: 10.4049/jimmunol.170.3.1481. [DOI] [PubMed] [Google Scholar]
- 45.Bogdanos DP, Lenzi M, Okamoto M, Rigopoulou EI, Muratori P, Ma Y, Muratori L, Tsantoulas D, Mieli- Vergani G, Bianchi FB, et al. Multiple viral/self immunological cross-reactivity in liver kidney microsomal antibody positive hepatitis C virus infected patients is associated with the possession of HLA B51. Int J Immunopathol Pharmacol. 2004;17:83–92. doi: 10.1177/039463200401700112. [DOI] [PubMed] [Google Scholar]