Hepatitis C viral load does not predict disease outcome: going beyond numbers

Evaluation of viral load in saliva from patients with chronic hepatitis C infection

Hepatitis C virus can be detected in blood and other bodily fluids, such as saliva. The aim of this study was to detect and quantify the HCV-RNA in saliva and plasma from patients with chronic hepatitis C infections, as well as check the level of viral load in sex groups (age, ethnicity and virus subtypes). Whole saliva and blood from 70 patients with chronic hepatitis C infections attended at the department of gastroenterology from University Hospital. The HCV-RNA load was performed by qRT-PCR using Sybr Green I master mix. HCV-RNA was detected in 80% (56/70) of patients in saliva and 92.85% (65/70) in plasma. The median of the viral load in the plasma was of 4.87 log10, and in saliva, it was 3.32log10, (p = 0.0005). Female patients and black patients exhibited a negative correlation between the HCV-RNA load in saliva vs. the HCV-RNA load in plasma (r = -0.3172, CI95% -0.6240 to -0.03736, p = 0.0491) and (r = -0.3141; IC95% -0.6069 to -0.05926; p = 0.0209), respectively. HCV-RNA was detected and quantified in saliva samples, and according to the quantification levels, saliva may be a possible transmission source of HCV, particularly in women and people of black ethnicity who develop chronic HCV infections.

A pilot study of interleukin-11 in subjects with chronic hepatitis C and advanced liver disease nonresponsive to antiviral therapy

OBJECTIVES

To evaluate the effects of recombinant human interleukin (rhIL)-11 on liver histology in patients with chronic hepatitis C virus (HCV) infection and advanced liver disease who had failed antiviral therapy.

METHODS

This was an open-label study of rhIL-11 (Neumega), Wyeth Laboratories, Collegeville, PA) at a dose of 5 microg/kg administered by subcutaneous injection daily for 12 wk. The primary efficacy endpoint was the change in the Knodell Histology Activity Index (HAI) between pre- and posttreatment liver biopsies. Secondary efficacy endpoints included changes in plasma alanine transaminase (ALT) concentrations and in the number of platelets.

RESULTS

The Knodell HAI improved in 11 (55%) of the 20 subjects enrolled, with the mean score improving from 7.3 to 5.9 (p= 0.006). Eight subjects (40%) experienced significant improvement as defined by a decrease of at least two points in the HAI. IL-11 treatment was also associated with a decrease in ALT levels from a mean level of 113 IU/L at baseline to 65 IU/L at week 12 (p < 0.001). Platelet levels increased from a mean of 143 x 10(3)/microl at baseline to 198 x 10(3)/mul at week 12 of treatment (p < 0.001). Overall, rhIL-11 was well tolerated and no serious adverse events (AEs) were reported. The most common AE was edema of the lower extremities, which occurred in all subjects.

CONCLUSIONS

The findings from this pilot study suggest that rhIL-11 may be beneficial for patients with hepatic inflammation and advanced liver disease associated with chronic HCV infection. Larger clinical trials are warranted to further evaluate the long-term antiinflammatory and antifibrotic effects of rhIL-11.

Humoral immunity to immunodominant epitopes of Hepatitis C virus in individuals infected with genotypes 1a or 1b

Cellular immunity against multiple Hepatitis C virus (HCV) proteins is observed in patients acutely infected with HCV most of whom later resolve infection. We wished to assess humoral immunity in patients infected with HCV 1a or 1b genotypes in relation to viral load using plasma samples from HCV-infected individuals and a panel of peptides representing immunodominant epitopes of HCV structural and nonstructural proteins. Plasma from HCV 1a- and 1b-infected patients, respectively, were divided into two groups: patients with low viral load (<==100,000 RNA copies/ml) and patients with high viral load (>/=10,000,000 RNA copies/ml). The antigens were peptides representing epitopes from immunodominant regions of HCV core, E2, NS3, and NS4 proteins, as well as the hypervariable (HVR) epitopes in E2 from genotypes 1a and 1b. Individuals infected with HCV 1a evoked a stronger immune response to many immunodominant epitopes of HCV relative to individuals infected with HCV 1b. Moreover, among individuals infected with HCV 1a, those with low viral loads mounted significantly greater responses against these epitopes than did individuals with high viral loads. Our observations demonstrate that quantitatively different antibody responses are elicited against HCV depending on the genotype of infecting virus, and suggest that humoral immunity directed against multiple immunodominant epitopes in HCV 1a-infected individuals may help lower viral load in vivo.

Hepatitis C virus dynamics and pathology: the role of CTL and antibody responses

This paper investigates the role of CTL and antibody responses in hepatitis C virus (HCV) dynamics and pathology. Mathematical models suggest that a strong CTL response is required for resolution of HCV infection and that a weak CTL response can result in persistent infection. According to the model, establishment of persistent infection is accompanied mainly by an ongoing antibody response, while CTLs are not maintained at high levels. In the model, this outcome correlates with absence of pathology. Persistent infection in the face of an ongoing antibody response can result in evolution of antigenic escape. According to the model, evolution towards escape from antibodies can shift the balance of immune responses so that the weak CTL levels become increasingly more dominant relative to antibodies. This shift results in onset of liver pathology as the virus evolves towards increased levels of antigenic escape. Therefore, the relative balance of the immune response can be a decisive factor that determines whether patients are asymptomatic or whether pathology is observed. Virus evolution can shift this balance towards pathology over time. Theoretical results are discussed in the context of published data.