Occult hepatitis C virus infection and its relevance in clinical practice

Occult Infection with Hepatitis C Virus: Looking for Clear-Cut Boundaries and Methodological Consensus

The sustained virologic response and elimination of HCV is widely viewed as a true cure of chronic hepatitis C as it associates with amelioration of histological liver damage and improved clinical outcomes. Therefore, the existence and clinical burden of occult HCV infection (OCI) has been a controversial issue for many years. In this review, we summarize recently published data that adds new information on the molecular and clinical background of OCI and its epidemiological significance. We also identify and discuss the most important methodological pitfalls, which can be a source of inconsistency between studies. Data that have accumulated so far, strongly support the existence of extrahepatic HCV replication in individuals negative for serum HCV-RNA by conventional clinical tests. OCI emerges as a condition where the immune system is unable to fully resolve infection but it is continuously stimulated by low levels of HCV antigens, leading to progression of liver pathology and extrahepatic HCV-related complications. Moreover, the development of monitoring strategies or management guidelines for OCI is still hampered by the lack of clear definition and the confusion regarding its clinical significance. Careful study design and the introduction of uniform protocols for the detection of low-level HCV-RNA are crucial for obtaining reliable data on OCI.

Occult hepatitis C virus infection in patients with malignant lymphoproliferative disorders

Despite the link between HCV and malignant lymphoproliferative disorders has been established, the association between occult hepatitis C virus infection and malignant lymphoproliferative disorders remains obscure. The present study intended to identify the possible association between occult HCV infection and malignant lymphoproliferative disorders. Newly diagnosed patients with LPDs were screened for the presence of HCV-RNA in both plasma and PBMCs. PBMCs of the subjects were also, examined by transmission and immuno-electron microscopy. LPD patients showed a high percentage of HCV infection (71.9%): OCI-HCV (37.5%) and HCV (34.38%). Meanwhile, 28.13% of LPD patients did not show any evidence of HCV infection. Ultrastructural examination of PBMCs revealed the presence of intracytoplasmic vacuoles enclosing viral like particles, which were less prominent in occult HCV patients. The possibility of occult HCV should be considered in patients with LPDs which can be helpful in the management of the treatment protocol in order to set up a balance between the control of the tumor progression and minimizing post chemotherapy complications related to HCV infection.

Recurrence of Cryoglobulinemia Secondary to Hepatitis C in a Patient with HCV RNA (-) Negative in the Serum

Hepatitis C virus infection is associated with many extrahepatic manifestations such as mixed cryoglobulinemia (MC). Renal manifestation of HCV infection might present as cryo-positive membranoproliferative glomerulonephritis (MPGN). First-line therapy includes antiviral treatment as the underlying infection leads to formation of immune complexes. After introducing direct-acting antiviral agents (DAAs) cure rates of HCV infection increased. Sustained virologic response (SVR) is defined as the absence of HCV RNA in serum by a sensitive test performed 12 or 24 weeks after the end of antiviral treatment. Although HCV RNA is undetectable in the serum, it may be present in hepatocytes and peripheral blood mononuclear cells (occult HCV infection). However, the impact of DAA treatment on occult HCV infection is not clear. We report a case of recurrence of MC with MPGN and development of lymphoproliferative disorder 2 years after achieving SVR.

Occult hepatitis C virus infection in the Middle East and Eastern Mediterranean countries: A systematic review and meta-analysis

BACKGROUND

The presence of hepatitis C virus (HCV) RNA in liver tissue or peripheral blood mononuclear cells with no identified virus genome in the serum has been reported worldwide among patients with either normal or elevated serum liver enzymes. The characterization of occult HCV infection (OCI) epidemiology in the Middle East and Eastern Mediterranean (M and E) countries, a region with the highest incidence and prevalence rates of HCV infection in the world, would be effective for more appropriate control of the infection.

AIM

To estimate the pooled prevalence of OCI in M and E countries using a systematic review and meta-analysis.

METHODS

A systematic literature search was performed using international, regional and local electronic databases. Some conference proceedings and references from bibliographies were also reviewed manually. The search was carried out during May and June 2020. Original observational surveys were considered if they assessed the prevalence of OCI among the population of M and E countries by examination of HCV nucleic acid in peripheral blood mononuclear cells in at least 30 cases selected by random or non-random sampling methods. The meta-analysis was performed using Comprehensive Meta-analysis software based on heterogeneity assessed by Cochran’s Q test and I-square statistics. Data were considered statistically significant at a P value < 0.05.

RESULTS

A total of 116 non-duplicated citations were found in electronic sources and grey literature. A total of 51 non-overlapping original surveys were appraised, of which 37 met the inclusion criteria and were included in the analysis. Data were available from 5 of 26 countries including Egypt, Iran, Pakistan, Saudi Arabia, and Turkey. The overall prevalence rate of OCI was estimated at 10.04% (95%CI: 7.66%-13.05%). The lowest OCI rate was observed among healthy subjects (4.79%, 95%CI: 2.86%-7.93%). The higher rates were estimated for patients suffering from chronic liver diseases (12.04%, 95%CI: 5.87%-23.10%), and multi-transfused patients (8.71%, 95%CI: 6.05%-12.39%). Subgroup analysis indicated that the OCI rates were probably not associated with the studied subpopulations, country, year of study, the detection method of HCV RNA, sample size, patients’ HCV serostatus, and sex (all P > 0.05). Meta-regression analyses showed no significant time trends in OCI rates among different groups.

CONCLUSION

This review estimated high rates of OCI prevalence in M and E countries, especially among multi-transfused patients as well as patients with chronic liver diseases.

Development of a gene signature for predicting cirrhosis risk score of chronic liver disease associated with HCV infection in Egyptians

BACKGROUND

Complex diseases such as fibrosis are likely polygenic. Lately, cirrhosis risk score (CRS) clearly discriminated Chronic HCV patients with high-risk versus those with low-risk for cirrhosis better than clinical factors.

METHODS

Herein, the CRS was assessed via genotyping by allelic discrimination assays in 243 HCV Egyptian patients categorized into 164 patients didn't develop HCC (93 mild, 71 advanced fibrosis); and 79 patients developed HCC. APRI and FIB-4 scores were calculated, compared with CRS and correlated with degree of fibrosis progression.

RESULTS

Median of the three CRS, APRI and FIB-4 scores were significantly elevated in late fibrotic and HCC patients (p < 0.001); however CRS displayed proper discrimination (mild fibrosis (0.59; 0.4-0.75), advanced fibrosis (0.75; 0.7-0.86) and HCC (0.73; 0.57-0.77); (p < 0.001)). The ROC analysis of CRS score displayed modest accuracy to discriminate between mild and advanced fibrotic patient; AUC was 0.73; p < 0.0001), while AUC was only 0.57 (p = 0.05) for the discrimination between HCC and no HCC. Moreover, the combination of CRS, APRI and FIB4 lessened the power of correlation (AUC, 0.63 (p < 0.0001)) in fibrosis prognosis. In HCC prognosis, the combination of CRS, APRI and FIB4 in HCC patients showed modest accuracy with AUC, 0.59 (p = 0.0001).

CONCLUSION

The diagnostic accuracy of FIB-4 for predicting liver fibrosis was nearly identical to that of CRS, however the strength of CRS score stemmed from that it is built on 7 SNPs host genetic factor. Our study validates non invasive algorithms for fibrosis prognosis purposes which may aid in decision making for therapeutic intervention.

Residual hepatitis C virus in peripheral blood mononuclear cell as a risk factor for hepatocellular carcinoma after achieving a sustained virological response: a dogma or fiction

BACKGROUND

Clinical worsening after achieving a sustained virological response (SVR) needs to be clarified and explained. Persistence of hepatitis C virus (HCV) core antigen interacts with the host proteins to interfere with signaling pathways and increases the susceptibility to hepatic carcinogenesis.

OBJECTIVE

This study aimed to investigate the risk factors that increase the progression of liver disease and hepatocellular carcinoma in a subgroup of HCV patients who achieved a SVR.

PATIENTS AND METHODS

Eighty-nine HCV patients with hepatic decompensation were selected 8.2 ± 1.8 months after achieving SVR24. HCV core antigen and HCV RNA were detected in peripheral blood mononuclear cells. Matched control (n = 100) and training (n = 200) groups were recruited.

RESULTS

Eighty-five patients showed a progression of Child-Turcotte-Pugh and model for end-stage liver disease scores, with positive RNA in peripheral blood mononuclear cell (357.4 ± 42.1 IU/million cell) and positive hepatitis C virus core antigen (n = 73); four patients were excluded. Susceptibility to decompensation and hepatocellular carcinoma after direct-acting antiviral drugs increased with age [odds ratio (OD) = 1.87], and was associated with male sex (OD = 1.65), diabetes (OD = 3.68), thrombocytopenia (OD = 2.44), pretreatment Alfa-fetoprotein (OD = 3.41), and occult HCV (OD = 4.1).

CONCLUSION

Clinical deterioration after SVR could be explained by occult HCV mainly in older male patients with diabetes and thrombocytopenia.

Evaluation of hepatitis C viral RNA persistence in HIV-infected patients with long-term sustained virological response by droplet digital PCR

Several studies have reported the persistence of HCV RNA in liver and/or peripheral blood mononuclear cells (PBMCs) in spite of undetectable viremia in patients who have achieved sustained virological response (SVR). This event, defined as occult HCV infection, remains controversial and low titers of persistent virus may be underestimated because it has not yet been analyzed by a highly sensitive test such as droplet digital PCR (ddPCR). This method provides an alternate ultra-sensitive detection technique for very low numbers of copies of viral RNA or DNA. The aim of this study was to evaluate the persistence of HCV in HIV-coinfected patients with long-term SVR using ddPCR. For each patient, the presence of HCV RNA in serum and PBMCs at baseline was determined by nested RT-ddPCR. Patients with HCV RNA in PBMCs at baseline were followed until the end of the study. One hundred and twenty-three patients were analyzed for persistence of HCV RNA in serum and PBMCs. Persistence of HCV was not found in serum in any patient. HCV RNA was detected in PBMCs in one patient (0.81%; 95% CI: 0.04–3.94) and resolved spontaneously during follow-up. Persistence of HCV RNA in PBMCs is not a common event in HIV/HCV co-infected patients with long-term SVR evaluated by RT-ddPCR.

Detection of residual HCV-RNA in patients who have achieved sustained virological response is associated with persistent histological abnormality

BACKGROUND

Whether achieving sustained virological response (SVR) in patients with hepatitis C attains complete elimination of hepatitis C virus (HCV) is unknown, because occult HCV infection (OCI), defined as the detection of HCV-RNA in hepatocytes or peripheral blood mononuclear cells (PBMC) in absence of serum HCV-RNA, may occur. We thus investigated the prevalence and clinical relevance of OCI.

METHODS

Subjects from three hospitals who had achieved serum HCV clearance, including 60 of Direct-acting antiviral agents (DAAs) induced SVR, 50 of pegylated interferon plus ribavirin (PR) induced SVR, and 30 of spontaneous resolution, were subjected to detect HCV-RNA in liver by robust RNAscope assay and PBMC by qPCR. Paired liver biopsies at baseline and at SVR24 were analyzed.

RESULTS

OCI was detected in 16 of 140 subjects (11.4%), with 15.0% in DAA-based group, 10.0% in PR group and 6.7% in spontaneously resolved group. In DAA-based subgroups, the incidence of OCI was gradually increased in group of solely DAA(s) therapy, combining DAA and PR therapy and combining DAA and ribavirin therapy. OCI is more frequent in patients with genotype 3. No correlation between baseline viral load, interleukin-28B genotype, baseline transaminases, post-SVR transaminases and OCI were found. However, OCI was significantly linked with severity of fibrosis and active inflammation at post-SVR, even considering basal fibrosis status. In addition, both the magnitude and the frequency of fibrosis regression were lower in patients with OCI than in those without OCI. In the multivariate analysis, PR therapy was identified an independent negative prognostic factor for both hepatic inflammation (P = .022) and fibrosis regression (P = .015). Importantly, we found HCV relapse in one of the OCI patients at 48 weeks after the end of PR treatment.

CONCLUSIONS

HCV-RNA can persist in hepatocytes and/or PBMC in a certain of patients who achieved spontaneous or treatment-induced HCV RNA clearance from serum and associated with persistent histological abnormality. Our findings provide new insights into cure of HCV and could influence the following-up scenario after SVR.

Neutrocyte-to-lymphocyte ratio predicts the presence of a replicative hepatitis C virus strand after therapy with direct-acting antivirals

Residual HCV-RNA can persist in liver tissue and peripheral blood mononuclear cells (PBMCs) long after antiviral therapy of chronic hepatitis C in patients repeatedly negative for viral RNA in serum. This occult infection associates with impaired immune response and the risk of lymphoproliferative disorders or progressive liver disease. There are currently no monitoring strategies for patients after treatment. We investigated if serum inflammation markers and interferon lambda (IFNL) genotype can be predictors of the presence of HCV-RNA and the replicative HCV-RNA (−) strand in patients who reached sustained virological response after interferon-free therapy. Forty-two consecutive patients who remained HCV-RNA negative in serum 24 weeks after the end of treatment (EOT) and during the follow-up were enrolled. Total HCV-RNA and HCV-RNA (−) strand were detected using ultrasensitive RT-PCR in PBMCs collected 12–15 months after EOT. Polymorphisms within IFNL3–IFNL4 region (rs12979860 and ss469415590) were genotyped with allele-specific PCR. Viral RNA was found in PBMCs from 31 (74%) patients, and of those 29 (69%) were also positive for HCV-RNA (−). Neither normalization of alanine aminotransferase nor IFNL genotype predicted the presence of residual HCV-RNA. A significantly higher neutrocyte-to-lymphocyte ratio (NLR) 24 weeks after the start of treatment predicted elimination of replicative HCV-RNA strand (OR 0.23; 95% CI 0.10–0.86; P = 0.019). Patients with no HCV-RNA (−) in PBMCs showed a greater increase in neutrocyte count between EOT and baseline (P = 0.028). Lack of significant elevation of NLR after therapy with direct-acting antivirals could predict the presence of residual replicative HCV-RNA strand in PBMCs.

IL-28B genetic variation, gender, age, jaundice, hepatitis C virus genotype, and hepatitis B virus and HIV co-infection in spontaneous clearance of hepatitis C virus

BACKGROUND/AIMS

Spontaneous viral clearance observed in some patients is one of the variants of the hepatitis C virus (HCV) infection natural history. We aimed to look at the complexity of factors affecting the spontaneous clearance of HCV (SC HCV).

MATERIALS AND METHODS

A total of 357 anti-HCV positive patients (309 with chronic hepatitis C and 48 patients with SC HCV) were included into the study. We studied the effects of the interleukin-28B (IL-28B) gene polymorphism, gender, age, the routes of virus transmission, past hepatitis C with jaundice, HCV genotype, and hepatitis B virus (HBV) and HIV co-infection on the outcome of HCV infection.

RESULTS

Based on the study results, the SC HCV was found in 48 individuals (13.4%). The most significant positive factors affecting the SC HCV included IL-28B single nucleotide polymorphism (SNP) rs12979860 (CC) and SNP rs8099917 (TT) (OR 4.03, p<0.001) and (OR 3.14, p<0.002), female gender (OR 2.72, p<0.001), young age (OR 2.30, p<0.008), and past history of jaundice (OR 5.12, p<0.001). The markers of a past HBV infection were found significantly more often in SC.

CONCLUSION

Positive predictors of the SC HCV include favorable IL-28B genotype, female gender, young age, a history of jaundice, markers of a past HBV infection, the absence of HIV infection, but not the viral genotype.

Hepatitis C virus serologic relapse after treatment with direct-acting antivirals is dependent on viral RNA levels in peripheral blood mononuclear cells and the grade of liver cirrhosis

The disappearance of hepatitis C virus (HCV) from serum and tissues for 12 weeks after the end of treatment (EOT) with direct-acting antivirals (DAAs) is known as a "sustained virologic response" (SVR) and occurs more frequently in non-cirrhotic patients than in cirrhotic patients. In this study, we evaluated the outcome of HCV treatment with sofosbuvir (SOF) plus ledipasvir (LDV) at both EOT and 12 weeks after EOT in patients with and without hepatic cirrhosis to address the relationship of serologic relapse to persistent infection of PBMCs and the frequency of hepatic encephalopathy and hepatocellular carcinoma (HCC) after treatment. Seventy-five patients with post-HCV liver cirrhosis were assigned to one of three groups (A, B, and C), each of which included 25 patients and corresponded to the patients' Child-Turcotte-Pugh (CTP) classification. All of the patients received a daily dose of SOF (400 mg) plus LDV (90 mg) for 24 weeks and were tested using HCV single-strand reverse transcription (SRT) and PCR analysis of PBMCs at both EOT and 12 weeks after EOT. Fourteen (18.7%) out of 75 patients (all study populations) had intra-PBMC HCV RNA, but only nine of them (64.3%) developed HCV RNA serum relapse (seroconversion) 12 weeks after EOT (P < 0.001). Encephalopathy was significantly higher in group C at EOT and 12 weeks after EOT (P < 0.05). Development of HCC was observed in decompensated patients of group C (2 out of 5 = 40.0%) 12 weeks post-EOT (P = 0.03). In conclusion, detection of HCV RNA within PBMCs at the EOT provides an indication of potential relapse after 12 weeks. Moreover, development of encephalopathy and HCC after HCV eradication by SOF plus LDV therapy is perhaps a future warning for post-treatment hepatic decompensation in cirrhotic patients.

Prevalence of Occult Hepatitis C Virus Infection among Blood Donors in Jiangsu, China

OBJECTIVE

In 2010, only 1 donor blood sample was found to be anti-hepatitis C virus (HCV) negative and HCV RNA positive, as detected by nucleic acid testing. In occult HCV infection (OCI), HCV RNA is found in peripheral blood mononuclear cells (PBMCs). We investigated the prevalence of OCI among blood donors.

METHODS

We collected 513 samples from 334 eligible and 179 deferred donors, including 55 anti-HCV-positive, 113 alanine aminotransferase (ALT)-elevated, and 11 hepatitis B virus surface antigen (HBsAg)-positive blood donors. PBMCs were isolated, the 5'-untranslated region of HCV RNA was amplified by reverse transcription nested PCR, and the genotype of the core region was determined.

RESULTS

No HCV RNA was detected among the eligible samples. Among the deferred donors, 15 (27.2%) had detectable HCV RNA in 55 anti-HCV PBMC specimens. HCV RNA was detected in 1 (9.1%) HBsAg-positive and 9 (8%) ALT-elevated samples. The prevalence of OCI in the blood donors was 2.2% (10/458). HCV genotypes were determined in 10 subjects, indicating that 2 (20.0%) were subtype 2a, 7 (70.0%) were 1b, and 1 (10%) was 6a.

CONCLUSIONS

This study showed that OCI does exist among Chinese blood donors. However, to determine the epidemiology and outcome of this HCV infection, further follow-up with more participants and patients receiving blood components with OCI is needed.

Practical guidelines for examination of adults with asymptomatic hypertransaminasaemia

The causes of sustained elevation of serum transaminases in asymptomatic adults, both hepatic and extrahepatic, are varied. In order to reach an aetiological diagnosis, a standardized protocol should be applied, aimed firstly at ruling out the most common causes, such as chronic hepatitis (viral or autoimmune), metabolic diseases, and toxic liver diseases. Several biochemical patterns, which take into account transaminase, cholestatic enzyme, muscle enzyme, ferritin and ceruloplasmin levels, as well protein electrophoresis and autoantibody measurement, will identify most causes. In cases in which a diagnosis cannot be reached with the use of these non-invasive methods, a needle liver biopsy will be justified.

Epidemiology of hepatitis C virus in Iran

In Iran, the prevalence of hepatitis C virus (HCV) infection is relatively low according to the population-based epidemiological studies. However, the epidemiology of HCV is changing and the rate of HCV infection is increasing due to the growth in the number of injecting drug users in the society. In addition, a shift has occurred in the distribution pattern of HCV genotypes among HCV-infected patients in Iran. Genotype 1a is the most prevalent genotype in Iran, but in recent years, an increase in the frequency of 3a and a decrease in 1a and 1b have been reported. These variations in the epidemiology of HCV reflect differences in the routes of transmission, status of public health, lifestyles, and risk factors in different groups and geographic regions of Iran. Health policy makers should consider these differences to establish better strategies for control and prevention of HCV infection. Therefore, this review was conducted to present a clear view regarding the current epidemiology of HCV infection in Iran.

A New Twist to a Chronic HCV Infection: Occult Hepatitis C

Background. The prevalence of occult hepatitis C infection (OCI) in the population of HCV-RNA negative but anti-HCV positive individuals is presently unknown. OCI may be responsible for clinically overt recurrent disease following an apparent sustained viral response (SVR) weeks to years later. Purpose. To review the available current literature regarding OCI, prevalence, pathogenic mechanisms, clinical characteristics, and future directions. Data Sources. Searching MEDLINE, article references, and national and international meeting abstracts for the diagnosis of OCI (1990-2014). Data Synthesis. The long-term followup of individuals with an OCI suggests that the infection can be transient with the loss of detectable HCV-RNA in PPBMCs after 12-18 months or alternatively exist intermittently and potentially long term. The ultimate outcome of HCV infection is decided by interplay between host immune responses, antiviral therapies, and the various well-identified viral evasion mechanisms as well as the presence of HCV infection within extrahepatic tissues. Conclusion. The currently widely held assumption of a HCV-cure in individuals having had "SVR" after 8-12 weeks of a course of DAA therapy as recently defined may not be entirely valid. Careful longitudinal followup utilizing highly sensitive assays and unique approaches to viral isolation are needed.

Xanthohumol, a main prenylated chalcone from hops, reduces liver damage and modulates oxidative reaction and apoptosis in hepatitis C virus infected Tupaia belangeri

Hepatitis C virus (HCV) infection in Tupaia belangeri (Tupaia) represents an important model of HCV infection. Xanthohumol (XN), a major prenylated chalcone from hops, has various biological activities including hepatopreventive and anti-viral activities. In this study, Tupaias infected with HCV RNA positive serum were used to evaluate the effects of XN on liver damage, oxidative reaction, apoptosis and viral protein expression in liver tissues. The Tupaias inoculated with HCV positive serum had elevated serum aminotransferase levels and inflammation, especially hepatic steatosis, and HCV core protein expression in liver tissue. In the animals inoculated with HCV positive serum, XN significantly decreased aminotransferase levels, histological activity index, hepatic steatosis score and transforming growth factor β1 expression in liver tissue compared with the animals without XN intervention. XN reduced HCV core protein expression in liver tissue compared with those without XN intervention but the difference was not significant. XN significantly decreased malondialdehyde, potentiated superoxide dismutase and glutathione peroxidase, reduced Bax expression, promoted Bcl-xL and inhibited caspase 3 activity in liver tissues compared with the animals without XN intervention. These results indicate that XN may effectively improve hepatic inflammation, steatosis and fibrosis induced by HCV in Tupaias primarily through inhibition of oxidative reaction and regulation of apoptosis and possible suppression of hepatic stellate cell activation. The anti-HCV potential of XN needs further investigation.