Treatment cessation in HBeAg-negative chronic hepatitis B: clinical response is associated with increase in specific proinflammatory cytokines.

Patients with HBeAg-negative chronic hepatitis B may experience an immune response after stopping nucleos(t)ide analogue (NA)therapy, which may potentially trigger HBsAg loss or off-therapy sustained viral control. The immunological mechanisms determining clinical response remain poorly understood. To identify inflammatory signatures associated with defined outcomes, we analysed plasma cytokines and chemokines from 57 HBeAg-negative patients enrolled in the Nuc-Stop Study at baseline and 12 weeks after NA cessation. Clinical response at 12 weeks was classified into four groups: immune control, viral relapse, evolving clinical relapse, and resolving clinical relapse. Twelve weeks after treatment cessation 17 patients (30%) experienced immune control, 19 (33%) viral relapse, 6 (11%) evolving clinical relapse, and 15 (26%) resolving clinical relapse. There was a significant increase in interferon-γ-induced protein 10 (IP-10; p = 0.012) and tumor necrosis factor (TNF; p = 0.032) in patients with evolving clinical relapse. Sparse partial least-squares multivariate analyses (sPLS-DA) showed higher first component values for the clinical relapse group compared to the other groups, separation was driven mainly by IP-10, TNF, IL-9, IFN-γ, MIP-1ß, and IL-12. Our results demonstrate that evolving clinical relapse after NA cessation is associated with a systemic increase in the proinflammatory cytokines IP-10 and TNF.Clinical trial registration: ClinicalTrials.gov, Identifier: NCT03681132.

Evaluation of the Effects of Remdesivir and Hydroxychloroquine on Viral Clearance in COVID-19 : A Randomized Trial.

BACKGROUND: New treatment modalities are urgently needed for patients with COVID-19. The World Health Organization (WHO) Solidarity trial showed no effect of remdesivir or hydroxychloroquine (HCQ) on mortality, but the antiviral effects of these drugs are not known. OBJECTIVE: To evaluate the effects of remdesivir and HCQ on all-cause, in-hospital mortality; the degree of respiratory failure and inflammation; and viral clearance in the oropharynx. DESIGN: NOR-Solidarity is an independent, add-on, randomized controlled trial to the WHO Solidarity trial that included biobanking and 3 months of clinical follow-up (ClinicalTrials.gov: NCT04321616). SETTING: 23 hospitals in Norway. PATIENTS: Eligible patients were adults hospitalized with confirmed SARS-CoV-2 infection. INTERVENTION: Between 28 March and 4 October 2020, a total of 185 patients were randomly assigned and 181 were included in the full analysis set. Patients received remdesivir (n = 42), HCQ (n = 52), or standard of care (SoC) (n = 87). MEASUREMENTS: In addition to the primary end point of WHO Solidarity, study-specific outcomes were viral clearance in oropharyngeal specimens, the degree of respiratory failure, and inflammatory variables. RESULTS: No significant differences were seen between treatment groups in mortality during hospitalization. There was a marked decrease in SARS-CoV-2 load in the oropharynx during the first week overall, with similar decreases and 10-day viral loads among the remdesivir, HCQ, and SoC groups. Remdesivir and HCQ did not affect the degree of respiratory failure or inflammatory variables in plasma or serum. The lack of antiviral effect was not associated with symptom duration, level of viral load, degree of inflammation, or presence of antibodies against SARS-CoV-2 at hospital admittance. LIMITATION: The trial had no placebo group. CONCLUSION: Neither remdesivir nor HCQ affected viral clearance in hospitalized patients with COVID-19. PRIMARY FUNDING SOURCE: National Clinical Therapy Research in the Specialist Health Services, Norway.

Estimating the attributable fraction of cirrhosis and hepatocellular carcinoma due to hepatitis B and C.

A goal of the WHO strategy on the elimination of hepatitis as a public threat is a 65% reduction in the attributable mortality. Deaths related to hepatitis B and C infections are mostly due to decompensated cirrhosis and hepatocellular carcinoma (HCC) but accurately measuring mortality is challenging as death certificates often do not capture the underlying disease. The aim of this collaborative study between European Centre for Disease Prevention and Control (ECDC) and the European Association for the Study of the Liver (EASL) was to assess a WHO-developed protocol to support countries in implementing studies to collect data on the fraction of cirrhosis and hepatocellular carcinoma attributable to hepatitis B and C. Three sentinel sites (in Bulgaria, Norway and Portugal) collected data for patients first admitted or seen in their centres during 2016. Patients with cirrhosis or HCC were identified through patient files or healthcare databases using ICD-10 codes. The proportion of patients with cirrhosis and HCC who tested positive for HBV and HCV were calculated to estimate the aetiological fractions. After the pilot study was completed, each site was asked about the feasibility and acceptability of the protocol. A total of 1249 patients presenting with cirrhosis and/or HCC were evaluated across the three sites. The prevalence of HBV and HCV among cases of cirrhosis showed that in Norway and Portugal, HCV was responsible for about one-quarter of the cases, whereas in Bulgaria, HBV was more common. For HCC, HCV was responsible for more than one-third of cases in Norway and Portugal, while in Bulgaria HBV was more frequent as the underlying cause. Results obtained during the pilot study were comparable to published estimates obtained through statistical modelling or meta-analyses. Several challenges were reported from the sites involved in the pilot including the considerable time needed for reviewing the hospital records and extracting patient data. The pilot demonstrated the feasibility of collecting data on the prevalence of HBV and HCV infection among patients with cirrhosis and HCC in sentinel sites. This method can be used to estimate mortality attributable to HBV and HCV for elimination monitoring. Where easily implementable, sentinel studies are the best way to empower countries, get up-to date data and closely monitor the changes in the attributable fraction at a country level.

Modelling the burden of hepatitis C infection among people who inject drugs in Norway, 1973-2030.

BACKGROUND: Lack of Hepatitis C virus (HCV) incidence data in (Norwegian) high-risk groups impedes the ability to make informed decisions on prevention measures. Thus we rely on modelling to estimate the incidence and burden of HCV infections. METHODS: We constructed a compartmental model for HCV infections in Norway among active and former people who inject drugs (PWIDs). We based yearly transition rates on literature. The model was fitted to absolute numbers of hepatitis C associated cirrhosis, hepatocellular carcinoma (HCC) and death from national data sources (2000-2013). We estimated the number (95%CI) of HCV infections, cirrhosis, HCC and death and disability adjusted life years (DALYs) due to HCV infections in Norway, 1973-2030. We assumed treatment rates in the projected period were similar to those in 2013. RESULTS: The estimated proportion of chronic HCV (including those with cirrhosis and HCC) among PWIDs was stable from 2000 (49%; 4441/9108) to 2013 (43%; 3667/8587). We estimated that the incidence of HCV among PWIDs was 381 new infections in 2015. The estimated number of people with cirrhosis, HCC, and liver transplant was predicted to increase until 2022 (1537 people). DALYs among active PWIDs estimated to peak in 2006 (3480 DALYs) and decrease to 1870 DALYs in 2030. Chronic HCV infection contributes most to the total burden of HCV infection, and peaks at 1917 DALYs (52%) in 2007. The burden of HCV related to PWID increased until 2006 with 81/100,000 DALYs inhabitants and decreased to 68/100,000 DALYs in 2015. CONCLUSION: The burden of HCV associated with injecting drug use is considerable, with chronic HCV infection contributing most to the total burden. This model can be used to estimate the impact of different interventions on the HCV burden in Norway and to perform cost-benefit analyses of various public health measures.

Sofosbuvir based treatment of chronic hepatitis C genotype 3 infections-A Scandinavian real-life study.

BACKGROUND AND AIMS: Chronic hepatitis C virus (HCV) genotype 3 infection with advanced liver disease has emerged as the most challenging to treat. We retrospectively assessed the treatment outcome of sofosbuvir (SOF) based regimes for treatment of HCV genotype 3 infections in a real life setting in Scandinavia. METHODS: Consecutive patients with chronic HCV genotype 3 infection were enrolled at 16 treatment centers in Denmark, Sweden, Norway and Finland. Patients who had received a SOF containing regimen were included. The fibrosis stage was evaluated by liver biopsy or transient liver elastography. The following treatments were given according availability and local guidelines: 1) SOF + ribavirin (RBV) for 24 weeks, 2) SOF + daclatasvir (DCV) +/-RBV for 12-24 weeks, 3) SOF + pegylated interferon alpha (peg-IFN-α) + RBV for 12 weeks or 4) SOF/ledipasvir (LDV) + RBV for 12-16 weeks. The primary endpoint was sustained virological response (SVR) assessed at week 12 (SVR12) after end of treatment. RESULTS: We included 316 patients with a mean age of 55 years (range 24-79), 70% men, 49% treatment experienced, 58% with compensated cirrhosis and 12% with decompensated cirrhosis.In the modified intention to treat (mITT) population SVR12 was achieved in 284/311 (91%) patients. Among 26 treatment failures, five had non-response, 3 breakthrough and 18 relapse. Five patients were not included in the mITT population. Three patients died from reasons unrelated to treatment and two were lost to follow-up. The SVR12 rate was similar for all treatment regimens, but lower in men (p = 0.042), and in patients with decompensated liver disease (p = 0.004). CONCLUSION: We found that sofosbuvir based treatment in a real-life setting could offer SVR rates exceeding 90% in patients with HCV genotype 3 infection and advanced liver disease.

Hepatitis C virus core antigen: A simplified treatment monitoring tool, including for post-treatment relapse.

BACKGROUND: Simple, affordable diagnostic tools are essential to facilitate global hepatitis C virus (HCV) elimination efforts. OBJECTIVES: This study evaluated the clinical performance of core antigen (HCVcAg) assay from plasma samples to monitor HCV treatment efficacy and HCV viral recurrence. STUDY DESIGN: Plasma samples from a study of response-guided pegylated-interferon/ribavirin therapy for people who inject drugs with chronic HCV genotype 2/3 infection were assessed for HCV RNA (AmpliPrep/COBAS Taqman assay, Roche) and HCVcAg (ARCHITECT HCV Ag, Abbott Diagnostics) during and after therapy. The sensitivity and specificity of the HCVcAg assay was compared to the HCV RNA assay (gold standard). RESULTS: A total of 335 samples from 92 enrolled participants were assessed (mean 4 time-points per participant). At baseline, end of treatment response (ETR) and sustained virological response (SVR) visits, the sensitivity of the HCVcAg assay with quantifiable HCV RNA threshold was 94% (95% CI: 88%, 98%), 56% (21%, 86%) and 100%, respectively. The specificity was between 98 to 100% for all time-points assessed. HCVcAg accurately detected all six participants with viral recurrence, demonstrating 100% sensitivity and specificity. One participant with detectable (non-quantifiable) HCV RNA and non-reactive HCVcAg at SVR12 subsequently cleared HCV RNA at SVR24. CONCLUSIONS: HCVcAg demonstrated high sensitivity and specificity for detection of pre-treatment and post-treatment viraemia. This study indicates that confirmation of active HCV infection, including recurrent viraemia, by HCVcAg is possible. Reduced on-treatment sensitivity of HCVcAg may be a clinical advantage given the moves toward simplification of monitoring schedules.

Liver fibrosis progression at autopsy in injecting drug users infected by hepatitis C: a longitudinal long-term cohort study.

BACKGROUND & AIMS: There is a paucity of unbiased data on the natural history of hepatitis C virus (HCV) infection in injecting drug users (IDUs). The purpose of this study was to assess the risk of developing advanced fibrosis associated with chronic hepatitis C (CHC) infection among injecting drug users (IDUs) who underwent an autopsy. METHODS: A longitudinal cohort design was applied, in which the stage of liver fibrosis in anti-HCV positive IDUs with or without chronic HCV infection was assessed in liver tissue from autopsies performed up to 35 years after HCV exposure. The cohort originated from 864 IDUs consecutively admitted for drug abuse treatment 1970-1984. Stored sera, mostly drawn at the time of admission for drug treatment, were available in 635 subjects. 220 out of 523 anti-HCV positive subjects had died before 2009. Liver tissue from autopsies was available from 102/220 subjects, of which 61 were HCV RNA positive. Liver sections were classified according to METAVIR scores for fibrosis. Two pathologists, both blinded for serologic results, scored sections of liver tissue. RESULTS: Among HCV RNA positive subjects 16.4% (10/61) had septal fibrosis (F3) or cirrhosis (F4) compared to 2.4% (1/41) among anti HCV positive/HCV RNA negative subjects (p=0.026). Of 18 HCV RNA positive subjects autopsied <15 years after HCV exposure none had F3 or F4. Among subjects autopsied >25 years after exposure 35% (6/17) had F3-F4. CONCLUSIONS: Among IDUs chronically infected by HCV, 1/3 developed septal fibrosis or cirrhosis 25 years or more after exposure.

All-cause and liver-related mortality in hepatitis C infected drug users followed for 33 years: a controlled study.

BACKGROUND & AIMS: The course of chronic hepatitis C virus (HCV) in injecting drug users (IDUs) has not been well described. The aim of this study was to compare long-term all-cause and liver-related mortality among anti-HCV positive IDUs with and without persisting HCV infection. METHODS: A retrospective-prospective controlled cohort design was applied. All IDUs admitted to resident drug treatment (1970-1984) and with available stored sera were screened for anti-HCV antibody. Anti-HCV positive individuals were further tested for the presence of HCV RNA. All-cause and liver-related mortality was compared between HCV RNA positive (n=328) and HCV RNA negative individuals (n=195). The observation was accomplished through register linkage to national registers. Mean observation time was 33 years. RESULTS: All-cause mortality rate was 1.85 (95% CI 1.62-2.11) per 100 person-years, male 2.11 (95% CI 1.84-2.46), female 1.39 (95% CI 1.07-1.79). Mortality rates were not influenced by persisting HCV infection. Main causes of death were intoxications (45.0%), suicide (9.1%), and accidents (8.2%). Liver disease was the cause of death in 7.5% of deaths among HCV RNA positive subjects. Five of 13 deaths among male IDUs with persisting HCV infection occurring after the age of 50 years were caused by liver disease. CONCLUSIONS: The all-cause mortality in IDUs is high and with no difference between HCV RNA positive and HCV RNA negative individuals, the first three decades after HCV transmission. However, among IDUs with chronic HCV infection who have survived until 50years of age, HCV infection emerges as the main cause of death.

Management of adverse effects of Peg-IFN and ribavirin therapy for hepatitis C.

HCV infects approximately 2-3% of the global population and is a leading cause of end-stage liver disease and hepatocellular carcinoma. Treatment of HCV infection with Peg-IFN in combination with ribavirin can eradicate HCV infection in 40-90% of patients; however, a major barrier to treatment uptake and delivery is the association of this therapy with frequent and, at times, serious adverse effects. Recognition and effective management of these adverse effects are critical components of the successful treatment of chronic HCV infection. In clinical trials, approximately 10-15% of patients discontinue Peg-IFN and ribavirin therapy due to adverse effects; however, in clinical practice, the rate of treatment discontinuation has been reported to be substantially higher. The off-target effect of Peg-IFN and ribavirin impacts most, if not all, organ systems; the most common adverse effects are hematologic, dermatologic, neurologic, immunologic, gastrointestinal, pulmonary, cardiovascular, and ocular. Regional and global variability exists in the nature of these adverse effects and the strategies employed to ameliorate their impact. This article provides a comprehensive literature review that systematically describes the adverse effects of Peg-IFN-α and ribavirin on various organ systems and, more importantly, recommends consensus approaches to managing those effects.

Liver fibrosis in hepatitis C patients of Pakistani versus Scandinavian origin.

OBJECTIVE: The aim of this study was to examine the significance of native country for the stage of liver fibrosis in a population of HCV patients of Pakistani or Scandinavian origin living in Oslo. PATIENTS AND METHODS: We included 122 consecutive HCV patients at two hepatitis clinics in Oslo, 73 of Scandinavian and 49 of Pakistani origin. Inclusion criteria were being HCV RNA positive, treatment naïve and having an adequate liver biopsy. The biopsies were scored according to the Metavir index, which scores fibrosis on a scale from 0 to 4 and necroinflammatory activity on a scale from 0 to 3. Steatosis was scored according to the percentage of hepatocytes having lipid droplets in their cytoplasm. Demographical, clinical, virological and biochemical data for the two groups were registered from the patient files. RESULTS: The median age was 43 and 42 years and 53% and 51% were male among the Scandinavian and Pakistani patients, respectively. Among the patients of Pakistani origin 18/49 (37%) had bridging fibrosis (F3) or cirrhosis (F4) compared to 11/73 (15%) Scandinavian patients (p=0.006). The mean fibrosis score was 1.78 in the Pakistani and 0.82 in the Scandinavian group (p<0.001). The mean necroinflammatory activity score was 1.22 and 0.78 in the Pakistanis and Scandinavians, respectively (p<0.001). In the Pakistani group more patients had ≥5% steatosis (59% vs. 33%; p=0.004), diabetes mellitus (24% vs. 0%; p<0.001), overweight (46% vs. 34%; p=0.232), genotype 3 (84% vs. 42%; p<0.001) and ALT and AST levels above the reference range (84% vs. 64%; p=0.020 and 88% vs. 68%; p=0.014) compared to the Scandinavian. Multivariate regression analyses identified age ≥40 years (OR 10.13; 95% CI 2.65-39.12) and genotype 3 (OR 5.02; 95% CI 1.19-21.17) as independent predictors of bridging fibrosis/cirrhosis. CONCLUSIONS: In HCV patients of similar age, those of Pakistani origin had more advanced liver disease than those of Scandinavian origin. Possible explanations are longer duration of the infection and higher occurrence of diabetes mellitus, liver steatosis and genotype 3 in the Pakistani group.

In patients with HCV genotype 2 or 3 infection and RVR 14 weeks treatment is noninferior to 24 weeks. Pooled analysis of two Scandinavian trials.

AIM: To compare 14 and 24 weeks treatment to patients with HCV genotype 2 or 3 infection and rapid virological response (RVR). MATERIALS AND METHODS: Patients included in two Scandinavian trials, one nonrandomized pilot trial (n=122) and one randomized controlled trial (RCT) (n=428) were entered into a pooled database. In both trials treatment naïve patients with genotype 2 or 3 were treated with pegylated interferon alpha 2b (1.5 microg/kg, subcutaneous) weekly and ribavirin (800-1400 mg, orally) daily. Primary endpoint was sustained virological response (SVR). RVR was defined as HCV RNA less than 50 IU/ml after 4 weeks of treatment. In the pilot trial all patients with RVR were treated for 14 weeks and in the RCT patients with RVR were randomised to either 14 or 24 weeks treatment. Patients treated per protocol were included in the primary analysis. The noninferiority margin was set to be 10% between the two groups with a one-sided 5% significance level. RESULTS: In patients with RVR and genotype 2 or 3 SVR was obtained in 181 of 199 (91.0%) and 93 of 98 (94.9%) after 14 and 24 weeks treatment, respectively. The observed difference in SVR rates was 3.9% (90% confidence interval: +1 to -8.8). The relapse rate was highest among those older than 40 years and those with genotype 3 and high viral load, but prolongation of treatment from 14 to 24 weeks did not reduce the relapse rate substantially in any of these groups. CONCLUSION: In patients with HCV genotype 2 or 3 infection and RVR 14 weeks treatment is noninferior to 24 weeks.

Individualized treatment of chronic hepatitis C with pegylated interferon and ribavirin.

Chronic infection with hepatitis C virus (HCV) is a major public health problem, with perhaps 180 million people infected worldwide. A significant proportion of these will eventually develop clinical complications, such as cirrhosis, liver decompensation and hepatocellular carcinoma. Sustained virological response (SVR) to antiviral therapy is associated with improvement in liver histology and survival free of liver-related complications. Great effort has been made to improve SVR rate by adapting the duration of therapy according to HCV genotype and to on-treatment response. Rapid virological response (RVR, undetectable HCV RNA at week 4) usually has a high positive predictive value for achieving SVR and early virological response (EVR, ≥ 2 log reduction or undetectable HCV RNA at week 12) exhibits a high negative predictive value for non-response. Individualized approach can improve cost-effectiveness of HCV antiviral therapy by reducing side effects and the costs of therapy associated with unnecessary exposure to treatment and through extending therapy for those with unfavorable features. This article summarizes recent data on strategies of individualized treatment in naïve patients with mono-infection by the different HCV genotypes. The management of common side effects, the impact of HCV infection on health-related quality of life and the potential applications of host genomics in HCV therapy are also briefly discussed.

Health-related quality of life in patients with different stages of liver disease induced by hepatitis C.

OBJECTIVE: Patients with hepatitis C have been shown to have impaired health-related quality of life (HRQoL). The aim of this study was to determine HRQoL in patients in different stages of hepatitis C virus (HCV) and to compare HRQoL in HCV cirrhosis with non-HCV-induced cirrhosis. MATERIAL AND METHODS: Out of 489 consecutive patients who fulfilled the inclusion criteria, 472 (96%) agreed to participate in the study: 158 patients with mild/moderate fibrosis with chronic hepatitis C (CHC group), 76 patients with HCV compensated cirrhosis (CC), 53 patients with HCV decompensated (DC) cirrhosis, 52 non-cirrhotic patients with sustained viral response (SVR), and a control group consisting of 32 patients with non-HCV CC and 101 with non-HCV DC who completed the Short Form-36 (SF-36) and EQ-5D questionnaire. RESULTS: The CHC group had significantly lower SF-36 scores than healthy controls, with the exception of scores for the dimensions physical function and bodily pain. HCV patients with DC had lower scores in all SF-36 dimensions in comparison with those of the CHC group, as well as in physical and mental component summaries (p<0.001). In comparison with the CHC group, the HCV CC group had lower scores on the SF-36 general health dimension (p<0.05) and lower SF-36 physical component summary (PCS) scores (p<0.05). No major differences were seen in patients with HCV- and non-HCV-induced cirrhosis. CONCLUSIONS: Impairment in HRQoL in patients with HCV was associated with the severity of liver disease, patients with decompensated cirrhosis exhibiting the highest impairment in HRQoL. The etiology of liver disease does not seem to be important in determining HRQoL in cirrhosis.

[Hepatitis C--a health problem also in Norway]. / Hepatitt C--et helseproblem også i Norge.

BACKGROUND: Hepatitis C is a large global health problem; approximately 20 - 30 000 are infected in Norway. Hepatitis C-infection is often chronic and can progress into chronic liver disease, liver cirrhosis and hepatocellular carcinoma. The most important transmission route is through percutaneous exposure to infected blood. The aim of this article is to describe the clinical course, microbiological diagnostic approaches, therapy, prophylaxis and public health aspects of Hepatitis C infection. MATERIAL AND METHODS: The paper is based on results from annual health examinations (conducted since 2001) of persons who abuse drugs intravenously in Oslo, from diagnostic work in a national reference laboratory for Hepatitis C and studies of literature (retrieved from Pubmed). RESULTS AND INTERPRETATION: The prevalence of Hepatitis C varies by country and subgroup of patients. In Norway the prevalence is 0.13 % among new blood donors, 0.7 % among pregnant women, 0.55 % in the general adult population and approximately 70 % among persons who abuse drugs intravenously. Treatment with pegylated interferon and ribavirin induces sustained virological response in 80 % of patients with genotypes 2 and 3 and in 30 - 40 % of those with genotype 1.

Treatment with pegylated interferon and ribavarin in HCV infection with genotype 2 or 3 for 14 weeks: a pilot study.

The aim of this study was to determine the efficacy of 14 weeks of treatment in patients infected with hepatitis C virus (HCV) genotype 2 or 3 who achieve early virological response (EVR). In a noncontrolled multicenter trial, 122 treatment-naive patients received 1.5 mug/kg pegylated interferon alfa-2b subcutaneously once weekly and 800 to 1,400 mg/d ribavirin based on body weight. Treatment was stopped at week 14 in patients with EVR, defined as undetectable HCV RNA at weeks 4 and 8. Patients without EVR were assigned to 24 weeks of treatment. The primary end point was sustained virological response (SVR), defined as undetectable HCV RNA 24 weeks after end of treatment. Among the 122 patients, 95 (78%) had EVR and received 14 weeks of treatment. The remaining 27 (22%) were treated for 24 weeks. SVR was obtained in 85 (90%) of 95 patients in the 14-week treatment group and 15 of (56%) 27 in the 24-week treatment group. Altogether, SVR was obtained in 100 of 122 patients (82%; 95% CI, 75%-89%). SVR after 14 weeks of treatment was achieved more frequently among genotype 3a patients with low viral load compared with high viral load (98% vs. 79%; P = .019). Logistic regression analysis showed that absence of bridging fibrosis/cirrhosis was the only independent predictor of SVR. In conclusion, patients with genotype 2 or 3 and EVR obtained a high SVR after 14 weeks of treatment. The results need to be confirmed in a randomized, controlled study before this treatment approach can be recommended, particularly for patients with genotype 3 and high viral load or severe fibrosis.