Evaluation of cellular immune responses and soluble mediators in patients with chronic hepatitis C virus (cHCV) infection

The Involvement of Neutrophil in the Immune Dysfunction Associated with BVDV Infection

Bovine viral diarrhea virus (BVDV) induces immune dysfunction that often results in a secondary bacterial infection in the infected animals. The underlying mechanism of BVDV-induced immune dysfunction is not well understood. The role of BVDV-infected macrophage-secreted factors was investigated. BVDV-infected monocyte-derived macrophage (MDM) supernatants down-regulated the expression of neutrophil L-selectin and CD18. Regardless of the biotype, phagocytic activity and oxidative burst were downregulated by BVDV-infected MDM supernatants. However, only supernatants from cytopathic (cp) BVDV down-regulated nitric oxide production and neutrophil extracellular traps (NET) induction. Our data suggested that BVDV-induced macrophage-secreted factors caused immune dysfunction in neutrophils. Unlike lymphocyte depletion, the negative impact on neutrophils seems to be specific to cp BVDV biotype. Interestingly the majority of modified live BVDV vaccines are based on cp strain of BVDV.

The Effect of Bovine Viral Diarrhea Virus (BVDV) Strains and the Corresponding Infected-Macrophages' Supernatant on Macrophage Inflammatory Function and Lymphocyte Apoptosis

Bovine viral diarrhea virus (BVDV) is an important viral disease of cattle that causes immune dysfunction. Macrophages are the key cells for the initiation of the innate immunity and play an important role in viral pathogenesis. In this in vitro study, we studied the effect of the supernatant of BVDV-infected macrophage on immune dysfunction. We infected bovine monocyte-derived macrophages (MDM) with high or low virulence strains of BVDV. The supernatant recovered from BVDV-infected MDM was used to examine the functional activity and surface marker expression of normal macrophages as well as lymphocyte apoptosis. Supernatants from the highly virulent 1373-infected MDM reduced phagocytosis, bactericidal activity and downregulated MHC II and CD14 expression of macrophages. Supernatants from 1373-infected MDM induced apoptosis in MDBK cells, lymphocytes or BL-3 cells. By protein electrophoresis, several protein bands were unique for high-virulence, 1373-infected MDM supernatant. There was no significant difference in the apoptosis-related cytokine mRNA (IL-1beta, IL-6 and TNF-a) of infected MDM. These data suggest that BVDV has an indirect negative effect on macrophage functions that is strain-specific. Further studies are required to determine the identity and mechanism of action of these virulence factors present in the supernatant of the infected macrophages.

Incidence of hospitalization for infection among patients with hepatitis B or C virus infection without cirrhosis in Taiwan: A cohort study

BACKGROUND

Infection is a major complication in liver cirrhosis and causes major morbidity and mortality. However, the incidence and mortality related to these conditions in patients infected with hepatitis C virus (HCV) are unclear, as is whether antiviral therapy could change their infection risk.

METHODS AND FINDINGS

In this community-based cohort study, a total of 115,336 adults (mean age 52.2 years; 35.6% men) without cirrhosis participating in the New Taipei City Health Screening in 2005-2008 were classified as having noncirrhotic HCV (NC-HCV) (n = 2,839), noncirrhotic hepatitis B virus (NC-HBV) (n = 8,316), or no HBV or HCV infection (NBNC) (n = 104,181). Participants were followed to their first hospitalization for infection or death after data linkage with the Taiwan National Health Insurance Research Database (NHIRD) and Death Registry. A Cox proportional hazard regression model, adjusted for age, sex, body mass index (BMI), smoking, alcohol consumption, education level, diabetes, renal function, systemic steroids, and history of hospitalization, was used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for overall and individual sites of infection and infection-related mortality. The reference group was NBNC participants with normal to mildly elevated alanine aminotransferase (ALT) (<1.5 times upper normal limit [UNL]) levels. To further address the impact of antiviral treatment on infection risk, we conducted analyses of data from the nationwide NHIRD and compared the risks for hospitalization because of infections and infection-related deaths between patients with HCV who received antiviral therapy (n = 20,264) and those who remained untreated (n = 104,360). During a median 8.2-year follow-up, the incidence of hospitalization for infection was substantially higher in NC-HCV patients. Compared to the reference group, NC-HCV was associated with a significantly higher risk for hospitalization because of overall infections (adjusted HR: 1.22; 95% CI: 1.12-1.33), but we observed no increased risk for patients in the NC-HBV (adjusted HR: 0.94; 95% CI: 0.88-1.01) or NBNC group with moderate to markedly elevated ALT levels (adjusted HR: 1.03; 95% CI: 0.93-1.14). For specific sites of infection, the NC-HCV group had increased risks for septicemia and lower respiratory tract, reproductive, and urinary tract infections. We noted no increased risk for infection-related death among patients with NC-HCV. Patients with HCV who received antiviral therapy had significantly reduced infection-related hospitalization and death risks (adjusted HR: 0.79; 95% CI: 0.73-0.84 for infection-related hospitalization and adjusted HR: 0.08; 95% CI: 0.04-0.16 for infection-related deaths). Study limitations include the exclusion of patients with cirrhosis from the cohort, the possibility of unmeasured confounding, and the lack of information on direct-acting antiviral agents (DAAs).

CONCLUSIONS

In this study, patients with NC-HCV were at increased risk for hospitalization for infection, while no increased risk was observed for NC-HBV-infected patients.

Does active hepatitis C virus infection increase the risk for infection due to Staphylococcus aureus?

Infections with Staphylococcus aureus may be more frequent in subjects with active hepatitis C virus (HCV) infection. In this retrospective dual-cohort study, we sought to determine whether persons with active HCV infection (positive HCV antibody, detectable blood HCV RNA) were at greater risk of S. aureus infection than those with spontaneously resolved HCV infection (positive HCV antibody, negative blood HCV RNA). Based on prestudy power calculation, we included 231 subjects with active HCV and 116 subjects with resolved HCV infection. The two groups were well matched at baseline, except that subjects with active HCV had a higher mean Charlson's comorbidity index (2.2 vs. 1.3; p < 0.0001). Cohorts were followed for a mean of 3.67 years. Thirty-one of the 231 (13%) subjects with active HCV infection developed ≥1 S. aureus infection(s) as compared to 4/116 (3.4%) subjects with resolved HCV (p = 0.004), with a trend towards more recurrent S. aureus infections in subjects with active HCV infection. The S. aureus infections were mostly serious, necessitating hospitalization and intravenous antibiotics. In the logistic regression, factors that independently predicted S. aureus infection were active HCV and Charlson's comorbidity index. Our regression models confirmed that the enhanced susceptibility to S. aureus infections was related to active HCV infection and not attributable solely to the increased number of comorbidities [adjusted odds ratio (OR) = 3.3, 95% confidence interval (CI) 1.1-9.8; p = 0.03]. This study shows that subjects with active HCV infection have a significantly higher incidence of serious S. aureus infections than those with spontaneously resolved HCV, even after adjustment for comorbidities.

High Serum Lipopolysaccharide-Binding Protein Level in Chronic Hepatitis C Viral Infection Is Reduced by Anti-Viral Treatments

Background

Lipopolysaccharide-binding protein (LBP) has been reported to associate with metabolic diseases, such as obesity, diabetes, and non-alcoholic fatty liver disease. Since chronic hepatitis C virus (HCV) infection is associated with metabolic derangements, the relationship between LBP and HCV deserves additional studies. This study aimed to determine the serum LBP level in subjects with or without HCV infection and investigate the change of its level after anti-viral treatments with or without interferon.

Methods and Findings

We recruited 120 non-HCV subjects, 42 and 17 HCV-infected subjects respectively treated with peginterferon α-2a/ribavirin and direct-acting antiviral drugs. Basic information, clinical data, serum LBP level and abdominal ultrasonography were collected. All the subjects provided written informed consent before being enrolled approved by the Research Ethics Committee of the National Taiwan University Hospital. Serum LBP level was significantly higher in HCV-infected subjects than non-HCV subjects (31.0 ± 8.8 versus 20.0 ± 6.4 μg/mL; p-value < 0.001). After multivariate analyses, LBP at baseline was independently associated with body mass index, hemoglobin A1c, alanine aminotransferase (ALT) and HCV infection. Moreover, the baseline LBP was only significantly positively associated with ALT and inversely with fatty liver in HCV-infected subjects. The LBP level significantly decreased at sustained virologic response (27.4 ± 6.6 versus 34.6 ± 7.3 μg/mL, p-value < 0.001; 15.9 ± 4.4 versus 22.2 ± 5.7 μg/mL, p-value = 0.001), regardless of interferon-based or -free therapy.

Conclusions

LBP, an endotoxemia associated protein might be used as an inflammatory biomarker of both infectious and non-infectious origins in HCV-infected subjects.

Review: The role of the liver in the response to LPS: experimental and clinical findings

The liver plays an important physiological role in lipopolysaccharide (LPS) detoxification and, in particular, hepatocytes are involved in the clearance of endotoxin of intestinal derivation. In experimental shock models, tumor necrosis factor (TNF)-α induces hepatocyte apoptosis and lethal effects are due to secreted TNF-α and not to cell-associated TNF-α. An exaggerated production of TNF-α has been reported in murine viral infections, in which mice become sensitized to low amounts of LPS and both interferon (IFN)-γ and IFN-α/β are involved in the macrophage-induced release of TNF-α. The prominent role of LPS and TNF-α in liver injury is also supported by studies of ethanol-induced hepatic damage. In humans, evidence of LPS-induced hepatic injury has been reported in cirrhosis, autoimmune hepatitis, and primary biliary cirrhosis and a decreased phagocytic activity of the reticulo-endothelial system has been found in these diseases. The origin of endotoxemia in hepatitis C virus (HCV) infected patients seems to be multifactorial and LPS may be of exogenous or endogenous derivation. In endotoxemic HCV-positive patients responsive to a combined treatment with IFN-α/ribavirin (RIB), endotoxemia was no longer detected at the end of the therapeutic regimen. By contrast, 48% of the non-responders to this treatment were still endotoxemic and their monocytes displayed higher intracellular TNF-α and interleukin (IL)-1β levels than responders. Moreover, in responders, an equilibrium between IFN-γ and IL-10 serum levels was attained. In the non-responders, serum levels of IL-10 did not increase following treatment. This may imply that an imbalance between T helper (Th)1 and Th2 derived cytokines could be envisaged in the non-responders.

Circulating Biomarkers and their Possible Role in Pathogenesis of Chronic Hepatitis B and C Viral Infections

The present study evaluated the plausible role of circulating biomarkers in immune pathogenesis of chronic hepatitis considered a priority in clinical hepatology. Total viral load of chronic hepatitis B virus (HBV) and hepatitis C virus (HCV) patients was quantified and correlation studies were performed with circulating levels of Th1/Th2 cytokines; C reactive protein and circulating nucleosomes; glutathione reductase (GR) and superoxide dismutase. To our knowledge, the study is first among its kind that validates strong positive correlation of viral load with IL-4, IL-6, GR in HBV and IL-6, IL-10, GR in HCV infections. Although, multi-centric studies including large cohorts are required for translating our findings to clinical practice, however, role of these biomarkers with potential diagnostic or prognostic significance might be helpful in clinical assessment of high-risk individuals, thereby, designing interventional strategies, towards development of personalized medicare. The results of our study also offer valuable insights of immune signaling mediators engaged in development of hepatocellular carcinoma.

Hepatitis C infection and the risk of bacteremia in hemodialysis patients with tunneled vascular access catheters

BACKGROUND

The major complication of tunneled vascular catheters in dialysis patients is infection. In preliminary work, an association was noted between hepatitis C virus (HCV) infection and bacteremia in these patients. On this basis, we theorized that HCV infection may be associated with bacteremia in dialysis patients with tunneled catheters.

METHODS

We conducted a two-phase clinical study to define the association between HCV infection and bacteremia in hemodialysis patients with catheters. Phase 1 was a cross-sectional study designed to assess the association between HCV serologic status and bacteremia. Phase 2 was a prospective study that examined the relationship between HCV viral load and bacteremia.

RESULTS

In Phase 1, HCV (+) patients had a significantly greater prevalence of bacteremia than HCV (-) patients (61 vs 7.7% respectively, P < 0.05). In Phase 2, the presence of detectable virus was associated with a numerical trend toward an increase in the incidence of bacteremia (40 vs 0% for patients with and without detectable virus, respectively, P = 0.09).

CONCLUSION

These studies suggest that HCV infection may be associated with the development of bacteremia in hemodialysis patients with tunneled catheters.

Interleukin 6 and 12, Alanine Aminotransferase Activity, and HCV Viral Load in Children with Chronic Hepatitis C Treated with Interferon and Ribavirin

The response to viral infections is mediated through the co-operation of cellular and humoral mechanisms. The aim of this study was to seek the correlation between IL-6 and IL-12 level, HCV viral load, ALT activity during the 48-week treatment with interferon-alpha-2b (IFN-alpha-2b) combined with ribavirin in children with diagnosed CHC and to search their influence on positive response to treatment. The group of 27 children with CHC was enrolled into this study. The children were treated with interferon-alpha and ribavirin in the course of 48-week therapy. The results show that both ALT activity and the viral load at the time of implementation of treatment with IFN-alpha and ribavirin is an important prognostic tool when treating children. It has been shown that the levels of IL-6 do not bear any significant prognostic importance to the implemented therapy, yet the increase of IL-12 levels in the 24th week of the treatment may be of prognostic value and may point out the possible elimination of HCV-RNA.

Candida esophagitis: Risk factors in non-HIV population in Pakistan

AIM: Candida esophagitis is a frequent infection in immunocompromised patients. This study was designed to determine its characteristics in non-human immune deficiency virus (HIV) infected patients attending a teaching hospital.

METHODS: Clinical records of all patients coded by international classification of diseases 9th revision with clinical modifications’ (ICD-9-CM), with candida esophagitis diagnosed by esophagogastroduodenoscopy (EGD) and histopathology over a period of 5 years were studied.

RESULTS: Fifty-one patients (27 males, 24 females, range 21-77 years old and mean age 52.9 years) fulfilled the criteria (0.34% of the EGD). The common predisposing factors were carcinoma (OR 3.87, CI 1.00-14.99) and diabetes mellitus (OR 4.39, CI 1.34-14.42). The frequent clinical symptoms were retrosternal discomfort, dysphagia and epigastric abdominal pain with endoscopic appearance of scattered mucosal plaques. Another endoscopic lesion was associated with candida esophagitis in 15% patients.

CONCLUSION: Carcinomas, diabetes mellitus, corticosteroid and antibiotic therapy are major risk factors for candida esophagitis in Pakistan. It is an easily managed complication that responds to treatment with nystatin.

Candida oesophagitis with hepatitis C virus: an uncommon association

Candida oesophagitis is an acquired immune deficiency syndrome (AIDS)-defining illness. We report a 28-year-old woman who presented with Candida oesophagitis with underlying chronic hepatitis C. The patient presented with anorexia and weakness and was noted to have raised serum transaminases. Upper-gastrointestinal endoscopy revealed Candida oesophagitis involving the whole oesophagus. Oesophageal biopsy demonstrated changes consistent with Candida oesophagitis. Serology was positive for hepatitis C antibodies, and polymerase chain reaction (PCR) genotyped hepatitis C virus (HCV) as genotype 3. Liver biopsy revealed chronic hepatitis with moderately active portal inflammation. A human immunodeficiency virus (HIV) test was non-reactive for types 1 and 2. The development of Candida oesophagitis in a patient with chronic HCV infection demands prompt consideration of general debility and immunosuppression as effects of HCV that led to an occurrence of opportunistic infection. Evaluation of this case provides insight into various mechanisms of immune suppression associated with HCV infection.

Recurrence of hepatitis C after liver transplantation is associated with increased systemic IL-10 levels

BACKGROUND

Recurrence of hepatitis C after liver transplantation is an almost universal occurrence. T-cell derived cytokines have an important role in the development of liver damage associated with chronic hepatitis C, their post-transplant levels, however, have not been correlated with histologic recurrence of the disease.

AIMS

We sought to analyze levels of TNF-alpha, soluble IL-2 receptor, IL-4 and IL-10 at 1 month, 6 months and 1 year after transplantation in 27 patients undergoing transplantation for hepatitis C related end-stage liver disease.

METHODS

HCV RNA levels were monitored by a branched-chain DNA signal amplification assay. Diagnosis of recurrent hepatitis was based on 1-year protocol biopsies and on biopsies performed for liver enzyme elevations.

RESULTS

Recurrent hepatitis C was detected in 52% (n=14) of the 27 patients. HCV RNA levels rose over time in all patients regardless of histologic recurrence. TNF-alpha, and IL-4 levels, although elevated, did not show specific patterns over time or in correlation with recurrence. Similarly, the early elevation followed by a gradual decrease over the first year in the amount of soluble IL-2 receptor was not related to histologic recurrence. We observed a significant increase in circulating IL-10 levels over the first year in patients with biopsy-proven recurrence, while patients with no signs of histologic recurrence displayed increased, but steady levels.

CONCLUSIONS

These results suggest that while these cytokines are associated with post-transplant recurrence of hepatitis C, their production may be altered by additional factors.

In vitro effects of naloxone on T-lymphocyte-dependent antibacterial activity in hepatitis C virus (HCV) infected patients and in inflammatory bowel disease (IBD) patients

Naloxone acts as an opioid antagonist, displacing opioid drugs from cellular receptors. Among opioid substances, beta-endorphins are able to bind to several cell receptors, even including those expressed by immune cells. In this respect, evidence has been provided that in the course of viral infections, as well as in patients with ulcerative colitis high levels of beta-endorphins are detectable. Here, peripheral blood lymphocytes (PBL) from 21 HCV infected patients and 14 patients with IBD, respectively, were incubated with Naloxone and Naloxone + Ca2+ in order to evaluate a putative modulation of PBL-mediated antibacterial activity. In fact, previous studies have demonstrated a reduction of this T-cell activity in HCV and IBD patients. In general terms, the above treatment led to a recovery of the depressed antibacterial activity. In some cases, increase in T lymphocyte function was obtained with Naloxone alone, while in other cases the combination Naloxone + Ca2+ gave rise to a restorative effect. Of note, in some instances, lymphocytes were unresponsive to pharmacological modulation. The overall results suggest that beta-endorphins may down modulate T-cell antibacterial response in HCV and in IBD patients by saturating peripheral receptors on immune cells. Therefore, it is likely that Naloxone and/or Naloxone + Ca2+ may displace opioid drugs, thus antagonizing their effects.

Combination therapy with ribavirin and alpha interferon for the treatment of chronic hepatitis C refractory to interferon

BACKGROUND

Up to 80% of hepatitis C patients are refractory to treatment with interferon-alpha. These patients are not likely to benefit from higher dosages or longer duration of interferon alone. The addition of ribavirin has been shown to improve the response rate in patients resistant to a previous course of interferon-alpha alone.

AIM

To evaluate whether a sustained hepatitis C virus (HCV) RNA response could be obtained with combination therapy of interferon-alpha and ribavirin in patients who did not respond to or relapsed after a standard interferon-alpha treatment.

METHODS

A total of 73 patients, 59 non-responders and 14 relapsers after interferon-alpha alone, were treated with a combination of ribavirin (1000-1200 mg/day) and interferon-alpha (3 MU three times a week) for 24 weeks. Alanine aminotransferase levels and HCV RNA were checked for 24 weeks after completion of therapy.

RESULTS

At the end of the combination therapy, 36 patients (49%) showed alanine aminotransferase normalization and in 20 patients (27%), HCV RNA was undetectable in serum. At the end of the 24 weeks follow-up period, only 12 patients (16%) had a sustained response with serum negativity of HCV RNA. This response was significantly higher in relapsers than in non-responders: five (36%) vs. seven (12%) patients (P=0.03), respectively. Adverse effects were restricted to flu-like symptoms and moderate haemolytic anaemia.

CONCLUSIONS

Combination of interferon-alpha and ribavirin is quite limited, both in scope and efficacy, in HCV patients who had a non-response to monotherapy with interferon. Better results may be expected in relapsers, but larger studies are necessary.

Serum cytokine values and fatigue in chronic hepatitis C infection

Patients with chronic hepatitis C infection often experience fatigue. In many clinical situations, an association between fatigue and altered serum cytokine levels has been found. Altered cytokine levels in patients with hepatitis C have not shown a correlation with the degree of serum transaminase elevation or pathological change on liver biopsy. The aim of our study was to examine whether there was an association between abnormal serum cytokine levels and fatigue in patients with compensated chronic hepatitis C. Patients referred to a tertiary care hepatology clinic who were hepatitis C antibody positive and who had elevated alanine aminotransferase (ALT) levels were eligible for entry into the study. A control group was also included. Subjects in both groups who had characteristics other than hepatitis C that were known to alter cytokine values and/or cause fatigue were excluded. Patients completed a validated questionnaire to determine their fatigue severity score (FSS). Bioassays were used to measure interleukin (IL)-1, IL-6 and tumour necrosis factor-alpha (TNF-alpha) levels in early morning serum samples taken from patients and controls. Altered cytokine values were defined as those more than two standard deviations above the mean control value. Data was analysed using SPSS, version 8.01. Of the 78 patients with chronic hepatitis C who participated in the study, 19 (24%), 24 (30%) and 45 (56%) had elevated levels of IL-1, IL-6 and TNF-alpha, respectively, compared with only two (6%) of the control group who had elevation of any of the three cytokines. No correlation was found between the FSS and serum cytokine levels, when analysed singly or in combination, in patients with chronic hepatitis C. Hence, alteration in early morning serum levels of IL-1, IL-6 and TNF-alpha in patients with chronic hepatitis C infection and elevated ALT levels bear no correlation with the symptom of fatigue.

Relationship between interferon-gamma, interleukin-10, and interleukin-12 production in chronic hepatitis C and in vitro effects of interferon-alpha

In the current study, increased interferon (IFN)-gamma, interleukin (IL)-10, and IL-12 p40 serum levels were observed in patients with chronic hepatitis C (CHC) compared to controls. Patients also displayed an increased spontaneous IFN-gamma release but a deficient peripheral blood mononuclear cells (PBMC) IFN-gamma production following stimulation with Staphylococcus aureus Cowan I strain (SAC). No difference was found with reference to spontaneous or phytohaemagglutinin (PHA)-induced IL-10 release between patients and controls, whereas a higher IL-12 p70 and IL-12 p40 secretion triggered by SAC was observed in patients. Moreover, IL-12 p40/p70 ratio following SAC stimulation was higher in patients compared to controls and a negative correlation was found between this ratio and IFN-gamma amounts. Recombinant IL-12 (rIL-12) as well as neutralizing anti-IL-10 monoclonal antibodies (mAbs) were able to restore the compromised IFN-gamma production. Of note, anti-IL-10 supplementation induced a lower IL-12 p40/p70 ratio in HCV subjects as compared to controls. Finally, IFN-alpha upregulated in vitro IFN-gamma, IL-10, and IL-12 p70 release but not IL-12 p40 secretion, this giving rise to a normalization of IL-12 p40/p70 ratio. The data suggest the occurrence of an enhanced responsiveness to IL-10 modulating effects, likely mediated by an imbalance of IL-12 p40/p70 ratio, in chronic HCV infection. Cytokine balance restoration might thus contribute to achieve therapeutical results in chronic hepatitis C.

Immunoresponsiveness in chronic hepatitis C patients: correlation between tissue and serum findings

In the present study, intrahepatic CD8+ lymphocyte infiltrates as well as HLA class I and CD54 (ICAM-1) antigen expression at both tissue and serum levels were evaluated in 54 untreated patients with chronic hepatitis C stratified on the basis of histological diagnosis (Chronic Persistent Hepatitis/Chronic Lobular Hepatitis -CPH/CLH- and Chronic Active Hepatitis -CAH-: 22 and 32 subjects, respectively). The relationships between soluble HLA-I (sHLA-I) and ICAM-1 (sICAM-1) serum levels and their membrane-bound counterparts, CD8+ liver infiltration and serum alanine aminotransferase (ALT) were also studied. A strong HLA-I and CD54 tissue expression, associated to the presence of CD8+ cell infiltrates in necro-inflammatory areas, and elevated sHLA-I and sICAM-1 serum amounts were observed in all patients. At the same time, no difference was found at tissue level between the two groups of patients with respect to the mean scores of HLA-I and CD54 expression, while CAH subjects displayed a significantly higher CD8 periportal and lobular reactivity in comparison to the other subset. Serological assays outlined higher values of circulating HLA-I molecules in CPH/CLH patients and higher sICAM-1 levels in the CAH group. Finally, a negative correlation was found between sHLA-I and ALT in CAH subjects while, in all patients, sICAM-1 positively correlated with both CD8 tissue infiltration and ALT. Our findings confirm the occurrence of an immune activation status during chronic hepatitis C and suggest that sHLA-I molecules might play a down-modulating role on immunoresponsiveness of these patients.

Increased peroxide production by polymorphonuclear cells of chronic hepatitis C virus-infected patients

To evaluate the oxidative burst in hepatitis C virus (HCV) infection, intracellular hydrogen peroxide (H2O2) production of polymorphonuclear (PMN) cells isolated from 15 chronic HCV-infected patients and 11 controls was assessed by flow cytometry in a time kinetic. Under nonstimulated and phorbol myristate acetate (PMA)-stimulated conditions, H2O2 production was higher in HCV-infected patients than in controls (P <0.05) at the time points of 20, 30, and 40 min. A positive correlation between H2O2 production by PMA-stimulated cells and serum levels of alanine aminotransferase and aspartate aminotransferase was found in the HCV-infected patients (r = 0.877, P <0.01 and r = 0.9351, P <0.001, respectively). RT-PCR analysis of purified mononuclear (MN) and PMN cells from HCV-infected patients revealed the presence of HCV RNA in 60% of MN and 27% of PMN cell samples. These results suggest that a functional alteration of PMN cells is manifested in this chronic viral infection which may represent an additional factor in the development of liver lesions.

Impairment of phagocytic and T-cell-mediated antibacterial activity and plasma endotoxins in patients with untreated gastrointestinal cancer

BACKGROUND

Cancer patients have multiple immune deficits, and mediators, such as prostaglandins, transforming growth factor-beta, and interleukin (IL)-10, may play a role in the pathogenesis of these immune dysfunctions.

METHODS

Fifty-six patients with gastrointestinal cancer (11 gastric cancer, 7 papilla of Vater cancer, and 38 colorectal cancer) were enrolled for this study, before starting conventional treatments. Phagocytosis and killing exerted by polymorphonuclear cells and monocytes, peripheral blood mononuclear cell absolute numbers, T-cell-mediated antibacterial activity, serum levels of IL-10 and interferon (IFN)-gamma, and plasma bacterial endotoxin concentration were evaluated.

RESULTS

Data show an impaired phagocytic and T-cell-mediated antibacterial activity in all cancer patients, whereas only in subjects with gastric cancer were IFN-gamma serum levels reduced. Circulating endotoxins were detected in 17 patients.

CONCLUSIONS

In untreated gastrointestinal cancer patients the capacity of phagocytes and T-cells to clear pathogens is reduced. This dysfunction may increase the risk of becoming infected and may account for the presence of endotoxin in 30% of patients.

Decrease of interferon gamma serum levels in patients with chronic hepatitis C

Cytokines can play a crucial role in defending the organism from viral infections. One of these, interferon gamma (IFN-gamma), possesses marked immunomodulating activity. As cell immunity seems to be involved in chronic hepatitis C virus (HCV), study of the events regulated by IFN-gamma may be useful in evaluating the host's immunological response. We studied 63 patients (36 males, 27 females) affected by chronic HCV and 28 (14 males, 14 females) healthy controls. IFN-gamma concentrations were significantly lower in the former, and were positively correlated with the histological activity index, suggesting that low IFN-gamma values play a part in determining chronicity. We believe they may be an unfavorable factor and may be useful in detecting patients who are not capable of eradicating the virus.

Soluble (s) CD14 and plasmatic lipopolysaccharides (LPS) in patients with chronic hepatitis C before and after treatment with interferon (IFN)-alpha

CDI4 is a monocyte/polymorphonuclear cell receptor for lipopolysaccharide (LPS)-LPS Binding Protein (LBP), which mediates most of the toxic effects exerted by such a bacterial component in the host. Here, we provide evidence that sCD14 and interferon (IFN)-gamma serum levels are significantly higher in chronic hepatitis C (CH-C) patients than those detected in normal donors. On the other hand, CD4+/CD8+ antibacterial activity is depressed, thus facilitating entry of bacteria into the host. Of note, all these immune parameters are not modified by in vivo IFN-alpha administration over a period of one year. Finally, after 12 months of IFN-alpha treatment number of CH-C patients with detectable levels of plasmatic LPS increased, thus indicating a continuous release of LPS into the host and also suggesting a putative pathogenetic role for sCD14 LPS-LBP complex in subjects affected by CH-C virus infection.

Chronic hepatitis C: T-helper1/T-helper2 imbalance could cause virus persistence in peripheral blood

Interferon gamma (IFN gamma) and interleukin 4, 10 and 12 (IL-4, -10, -12) production was measured in whole peripheral blood (WPB) and peripheral blood mononuclear cells (PBMC) of 10 chronic hepatitis C (CHC) patients. The level of IFN gamma in supernatants in mitogen-activated WPB was lower than in healthy donors. IL-10 served as a possible downregulative factor for IFN gamma, since its spontaneous IL-10 production was enhanced in CHC. Neutralization of IL-10 partly restored IFN gamma response in CHC patients. Recombinant IL-12 (rIL-12) also enhanced IFN gamma of CHC patients, but IL-12 production was decreased in CHC. Thus, IFN gamma production deficiency in CHC patients is secondary to blockage by high levels of IL-10-impaired IL-12 production.

Effects of interferon-alpha treatment on neutrophil oxidative metabolism, lymphocyte proliferation and monocyte HLA class I antigen expression in patients with chronic hepatitis C

Polymorphonuclear cell (PMN) oxidative metabolism, lymphocyte polyclonal proliferation and monocyte HLA class I antigen expression were evaluated at different intervals of time in patients with chronic hepatitis C (CH-C) subjected to a 6 month interferon alpha (IFN-alpha) treatment and divided into Responder ('R') and Nonresponder ('NR') subsets according to clinical outcome. Before therapy, all subjects exhibited multiple immune alterations even if to a different extent between 'R' and 'NR' subsets: an elevated superoxide anion (O2-) generation by suspended PMN, a failure to further increase neutrophil oxidative responsiveness under adherence conditions, an augmented phytohaemagglutin-induced lymphocyte proliferative capacity and an enhanced HLA class I antigen expression on CD14+ cells. IFN-alpha administration gave rise to a modulation of oxidative response in 'R' group only, since these individuals displayed an O2- release by suspended and adherent PMN which fell within normal values. At the same time, a decrease of lymphocyte proliferation occurred in both groups of patients during IFN-alpha therapy, even if it reached statistical significance in 'R' group only. Finally, a more marked difference between 'R' and 'NR' individuals was noted in terms of HLA class I antigen induction on CD14+ cells at the end of therapy, as a consequence of a reduced expression of these structures in 'NR' subjects. Altogether, these findings suggest the occurrence of a strict relationship between immunoresponsiveness and IFN-alpha induced therapeutical effects in CH-C patients.

Immunological effects following administration of interferon-alpha in patients with chronic hepatitis C virus (cHCV) infection

The immunological effects of interferon (IFN)-alpha administration were evaluated in 15 patients with cHCV infection. Individuals were treated with 6 MU of lymphoblastoid IFN-alpha three times a week for 6 months and with 3 MU three times a week for an additional 6 months. Patients were divided into responders (12 subjects) and nonresponders (3 subjects), respectively, according to alanine aminotransferase serum levels at the end of treatment. Before therapy (T0), absolute numbers of CD3+, CD4+, CD8+, CD14+ and CD16+ cells were significantly reduced in both groups when compared to normal values. At the same time, all patients displayed a profound decrease of phagocytosis and killing exerted by both polymorphonuclear cells (PMN) and monocytes (MO). However, MO Killing resulted to be normal in the responder group. With special reference to T cell function, T cell mediated antibacterial activity, using Salmonella typhi as a target, was also significantly reduced. After therapy (T12), in responder patients a significant increase of CD3+, CD4+, CD14+ and CD16+ cell absolute numbers was observed, while phagocytic and T cell functions were still depressed. Among the nonresponders, in two of three patients IFN-alpha administration gave rise to an increase (above normality) of CD3+, CD4+, CD8+, CD14+, CD16+ and CD20+ cell absolute numbers, while in one patient the same markers dramatically dropped below normal range. In two patients, antibacterial activity was significantly augmented by IFN-alpha treatment, whereas in one patient no modification was observed. Finally, in the same patients IFN-alpha did not correct PMN and MO pretreatment deficits.