Multi-analyte profile analysis of plasma immune proteins: altered expression of peripheral immune factors is associated with neuropsychiatric symptom severity in adults with and without chronic hepatitis C virus infection

BackgroundThe purpose of this study was to characterize hepatitis C virus (HCV)-associated differences in the expression of 47 inflammatory factors and to evaluate the potential role of peripheral immune activation in HCV-associated neuropsychiatric symptoms-depression, anxiety, fatigue, and pain. An additional objective was to evaluate the role of immune factor dysregulation in the expression of specific neuropsychiatric symptoms to identify biomarkers that may be relevant to the treatment of these neuropsychiatric symptoms in adults with or without HCV. MethodsBlood samples and neuropsychiatric symptom severity scales were collected from HCV-infected adults (HCV+, n = 39) and demographically similar noninfected controls (HCV-, n = 40). Multi-analyte profile analysis was used to evaluate plasma biomarkers. ResultsCompared with HCV- controls, HCV+ adults reported significantly (P < 0.050) greater depression, anxiety, fatigue, and pain, and they were more likely to present with an increased inflammatory profile as indicated by significantly higher plasma levels of 40% (19/47) of the factors assessed (21%, after correcting for multiple comparisons). Within the HCV+ group, but not within the HCV- group, an increased inflammatory profile (indicated by the number of immune factors > the LDC) significantly correlated with depression, anxiety, and pain. Within the total sample, neuropsychiatric symptom severity was significantly predicted by protein signatures consisting of 4-10 plasma immune factors; protein signatures significantly accounted for 19-40% of the variance in depression, anxiety, fatigue, and pain. ConclusionsOverall, the results demonstrate that altered expression of a network of plasma immune factors contributes to neuropsychiatric symptom severity. These findings offer new biomarkers to potentially facilitate pharmacotherapeutic development and to increase our understanding of the molecular pathways associated with neuropsychiatric symptoms in adults with or without HCV.

Protective effects of higher cognitive reserve for neuropsychological and daily functioning among individuals infected with hepatitis C

Higher levels of cognitive reserve (CR) can be protective against the neuropsychological manifestation of neural injury across a variety of clinical disorders. However, the role of CR in the expression of neurocognitive deficits among persons infected with the hepatitis C virus (HCV) is not well understood. Thirty-nine HCV-infected participants were classified as having either high (n = 19) or low (n = 20) CR based on educational attainment, oral word reading, and IQ scores. A sample of 40 demographically comparable healthy adults (HA) was also included. All participants completed the Neuropsychological Assessment Battery, Delis-Kaplan Executive Function System, and Behavioral Rating Inventory of Executive Function, Adult Version (BRIEF-A). Linear regression analyses, controlling for gender, depression, and lifetime substance use disorders, found significant effects of HCV/CR group on verbal fluency, executive functions, and daily functioning T scores, but not in learning or the BRIEF-A. Pairwise comparisons revealed that the HCV group with low CR performed significantly below the HCV high CR and HA cohorts, who did not differ from one another. Findings indicate that higher levels of CR may be a protective factor in the neurocognitive and real-world manifestation of neural injury commonly associated with HCV infection.

Differential antigenic hierarchy associated with spontaneous recovery from hepatitis C virus infection: implications for vaccine design

BACKGROUND

Cellular immune responses play a central role in the control of hepatitis C virus (HCV) infection, and in some individuals the adaptive immune response can spontaneously eradicate HCV infection. The development of vaccine candidates to prevent the spread of this infection remains a top priority; however, understanding the correlates of effective immunological containment is an important prerequisite.

METHODS

Using 750 overlapping peptides, we directly characterized ex vivo total and subgenomic HCV-specific CD4(+) and CD8(+) T cell responses in a large cohort of participants with either chronic infection or spontaneously resolved infection.

RESULTS

In chronic infection, the frequency of total CD4(+) T cells specific for HCV averaged 0.06%, compared with 0.38% in resolved infection. Total HCV-specific CD4(+) and CD8(+) T cell responses were strongly correlated in the setting of spontaneous resolution but not in the setting of viral persistence. NS3 protein-specific responses comprised a significantly greater proportion of the total response in resolved infection than in chronic infection, whereas responses to different regions comprised a larger proportion of responses in chronic infection.

CONCLUSION

Because these data comprehensively define the breadth, specificity, and threshold of the T cell response associated with spontaneous recovery from HCV infection, they have important implications in the development of multigenic vaccine candidates for this common infection.

Prospective multicenter study of eligibility for antiviral therapy among 4,084 U.S. veterans with chronic hepatitis C virus infection

BACKGROUND

Many veterans may not be candidates for hepatitis C virus (HCV) treatment due to contraindications to therapy. The aims of this study were to determine the proportion of HCV-infected veterans who were eligible for interferon alfa and ribavirin therapy and to evaluate barriers to HCV treatment.

METHODS

We prospectively enrolled 4,084 veterans who were referred for HCV treatment over a 1-yr period at 24 Veterans Affairs (VA) Medical Centers. Treatment candidacy was assessed using standardized criteria and the opinion of the treating clinician.

RESULTS

Overall, 32.2% (95% CI, 30.8-33.7%) were candidates for HCV treatment according to standardized criteria, whereas 40.7% (95% CI, 39.2-42.3%) were candidates in the opinion of the treating clinician. Multivariable analysis identified ongoing substance abuse (OR = 17.68; 95% CI, 12.24-25.53), comorbid medical disease (OR = 9.62; 95% CI, 6.85-13.50), psychiatric disease (OR = 9.45; 95% CI, 6.70-13.32), and advanced liver disease (OR = 8.43; 95% CI, 4.42-16.06) as the strongest predictors of not being a treatment candidate. Among patients who were considered treatment candidates, 76.2% (95% CI, 74.0-78.3%) agreed to be treated and multivariable analysis showed that persons >/=50 yr of age (OR = 1.37; 95% CI, 1.07-1.76) and those with >50 lifetime sexual partners (OR = 1.44; 95% CI, 1.08-1.93) were more likely to decline treatment.

CONCLUSIONS

The majority of veteran patients are not suitable candidates for HCV treatment because of substance abuse, psychiatric disease, and comorbid medical disease, and many who are candidates decline therapy. Multidisciplinary collaboration is needed to overcome barriers to HCV therapy in this population.

Comparative analysis of outcome following liver transplantation in US veterans

The purpose of this study was to evaluate whether there was a difference in mortality following orthotopic liver transplantation (OLT) in a US veteran (VA) population (n = 149) compared to a non-VA (university) population (n = 285) and what factors could explain this difference. Survival following OLT for 149 VA patients was compared with that of 285 university patients. By Kaplan-Meier survival analysis, VA patients had higher mortality than university patients with respective 1-year, 3-year, and 5-year survival of 82%, 75%, and 68% vs. 87%, 82%, and 78% (p = 0.006). Gender, etiology of end-stage liver disease (ESLD) and donor age (i.e. older than 34 years) also significantly influenced survival. However, when donor and recipient age, gender, model for end-stage liver disease (MELD) score, and etiology of liver disease were included with hospital status in a multivariate Cox proportional hazards model, the VA population did not have higher mortality. A final model to predict mortality following transplantation was derived for all 434 patients where individuals were assigned risk scores based on the equation R = 0.219 (gender) + 0.018 (donor age) + 0.032 (recipient age) + 0.021 (MELD), where recipient age, donor age, and MELD score are the respective continuous variables and gender = 1 (men) and 0 for women (c-statistic = 0.71).

Novel CD4+ and CD8+ T-cell determinants within the NS3 protein in subjects with spontaneously resolved HCV infection

Spontaneous resolution of hepatitis C virus (HCV) infection is a relatively infrequent event, and these individuals provide a unique opportunity to characterize correlates of protective immunity as an important first step in the development of vaccine candidates. The aim of this study was to directly and comprehensively enumerate HCV-nonstructural protein 3 (NS3) specific CD4(+) and CD8(+) T cells ex vivo from HLA diverse individuals who had been successful in spontaneously resolving HCV infection. We measured interferon gamma (IFN-gamma) production with an ELISPOT assay using magnetic bead-separated CD4(+) or CD8(+) T cells in response to autologous DCs that had been pulsed with 15mer per peptides overlapping by 11 amino acids and spanning all of the NS3 protein (150 total peptides). All subjects with spontaneously recovered HCV infection demonstrated vigorous and multispecific CD4(+) T-cell responses to NS3 peptides, and 6 of 10 subjects demonstrated CD8(+) T-cell responses. More importantly, we identified novel, previously unpredicted antigenic regions, which in most cases elicited high frequencies within a given individual. In conclusion, subjects who have spontaneously eradicated HCV infection up to 35 years earlier demonstrate persistent CD4(+) and CD8(+) T-cell responses specific to NS3. By providing a comprehensive screening of all potential T-cell epitopes contained in the NS3 region, our strategy defines the breadth of the T-cell response and identifies novel, unpredicted specificities.

Frequencies of HCV-specific effector CD4+ T cells by flow cytometry: correlation with clinical disease stages

Hepatitis C virus (HCV) is the leading cause of chronic hepatitis, affecting approximately 2% of the world's population. The immune mechanisms responsible for the highly variable natural history in a given individual are unknown. We used a multiparameter flow cytometric technique to functionally and phenotypically characterize HCV-specific effector T cells in the peripheral blood of 32 individuals with different stages of hepatitis C disease (resolved, mild chronic, advanced chronic) and normal controls. We found the highest frequencies of virus-specific effector cells with an activated memory phenotype (CD45RO+CD69+) in subjects who had resolved HCV infection, either spontaneously or with antiviral therapy. Effector cells from patients with resolved infection produced Th1 type cytokines following stimulation with nonstructural antigens (NS3 and NS4), whereas effector cells from chronically infected patients produced Th1 type cytokines predominantly following stimulation with the HCV core antigen. Stimulation with superantigen staphylococcal enterotoxin (SEB) induced the same levels of cytokine production in the different patient groups. Among the HCV-seropositive patients, viral load inversely correlated with the Th1 effector cell response to NS3. Interleukin (IL)-4 was produced only in response to the control antigens, but not in response to the HCV recombinant proteins. Taken together, these findings suggest that a vigorous HCV-specific CD4+ Th1 response, particularly against the nonstructural proteins of the virus, may be associated with viral clearance and protection from disease progression. Prospective studies using this new flow cytometric assay will be required to determine whether antiviral therapy modifies the frequency, specificity, and function of these virus-specific effector cells.

Molecular epidemiology of hepatitis C infection in U.S. veteran liver transplant recipients: evidence for decreasing relative prevalence of genotype 1B

OBJECTIVE

The U.S. Veteran population represents a unique patient group to study different HCV genotypes because of geographically diverse exposures. The aim of this study was to characterize the distribution of HCV genotypes in U.S. veterans undergoing liver transplantation (OLT), trace genotypes to modes of acquisition (risk behavior and location), and evaluate the relative prevalence of HCV genotypes according to the time of acquisition.

METHODS

Between 10/88 and 12/95, 110 primary OLTs were performed in U.S. Veterans at our center. Forty-nine (45%) patients had detectable HCV-RNA by PCR at the time of OLT. Determination of HCV genotypes was performed by restriction fragment length polymorphism of the 5' noncoding region and classified according to Simmonds et al.

RESULTS

Twenty-three of 49 (47%) veterans had 1a, 17 (35%) 1b, two (4%) 2a, three (6%) 2b, two (4%) 3a, two (4%) mixed (1a/2a, 1b/2a). This distribution of HCV genotypes was comparable to the genotypic distribution of a contemporary cohort of nonveteran OLT recipients at the University of Washington. There was a statistically significant association between illicit injection drug use (IDU) and 1a, with 63% of 1a patients having IDU whereas only 14% of 1b patients admitted to IDU (p = 0.03). All patients in whom the mode of acquisition was unknown had genotype 1b (p = 0.04). Intranasal cocaine use was strongly correlated with IDU (p = 0.002). Patients who had tattoos but no history of blood transfusion (BT) or recreational drug use had genotype 1 (2 had 1a, 2 had 1b; p = NS). Twenty-two (45%) patients had serological evidence of prior hepatitis B (HBV) infection. Patients who had genotype 2a, 2b, 3a, or mixed were much more likely to have had HBV (seven of nine, 78%) than patients with genotype 1a or 1b (15 of 40, 37.5%) (p = 0.03). There was no significant correlation between BT, dates, or military branch of service, high risk behavior in Southeast Asia, level of education, ethnicity, and particular genotype(s). Whereas the proportion of 1b accounting for HCV infection in patients with a first exposure before 1968 was 50%, all patients with a first exposure post-1975 were non-1b (p = 0.04), suggesting a change in the epidemiology of HCV in our cohort.

CONCLUSIONS

In U.S. Veterans undergoing OLT: 1) 45% had PCR-confirmed HCV infection, 2) 1a was the predominant genotype and was associated with IDU, and 3) a significant decrease in the prevalence of genotype 1b from the pre-Vietnam era to post-1975 suggests a changing epidemiology of HCV genotypes.

T cell receptor-beta mRNA splicing: regulation of unusual splicing intermediates

The expression of functional T cell receptor-beta (TCR-beta) transcripts requires the activation of programmed DNA rearrangement events. It is not clear whether other mechanisms dictate TCR-beta mRNA levels during thymic ontogeny. We examined the potential role of RNA splicing as a regulatory mechanism. As a model system, we used an immature T cell clone, SL12.4, that transcribes a fully rearranged TCR-beta gene but essentially lacks mature 1.3-kb TCR-beta transcripts in the cytoplasm. Abundant TCR-beta splicing intermediates accumulate in the nucleus of this cell clone. These splicing intermediates result from inefficient or inhibited excision of four of the five TCR-beta introns; the only intron that is efficiently spliced is the most 5' intron, IVSL. The focal point for the regulation appears to be IVS1C beta 1 and IVS2C beta 1, since unusual splicing intermediates that have cleaved the 5' splice site but not the 3' splice site of these two introns accumulate in vivo. The block in 3' splice site cleavage is of interest since sequence analysis reveals that these two introns possess canonical splice sites. A repressional mechanism involving a labile repressor protein may be responsible for the inhibition of RNA splicing since treatment of SL12.4 cells with the protein synthesis inhibitor cycloheximide reversibly induces a rapid and dramatic accumulation of fully spliced TCR-beta transcripts in the cytoplasm, concomitant with a decline in TCR-beta pre-mRNAs in the nucleus. This inducible system may be useful for future studies analyzing the underlying molecular mechanisms that regulate RNA splicing.

Fibrosing cytolytic liver failure secondary to recurrent hepatitis B after liver transplantation

Four patients who underwent transplantation for hepatitis B virus-related liver disease developed rapidly progressive liver failure attributable to recurrent hepatitis B disease typified by hyperbilirubinemia and distinctive hepatocyte ballooning and progressive fibrosis consistent with recently reported fibrosing cholestatic hepatitis. Among these four patients, the mean interval from transplantation to redocumentation of hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg) was 5 months, to development of malaise and jaundice 6 months, to histological diagnosis 7 months, and to graft failure 8 months. The only patient who underwent retransplantation had accelerated recurrence of the same syndrome with biopsy documentation 1 month later and graft failure 2 months later. Distinctive histological features included confluent hepatocellular ballooning and progressive periportal fibrosis followed by lobular collapse over 4-6 weeks without significant inflammation. Immunohistochemical staining showed marked HBsAg and hepatitis B core antigen (HBcAg) immunoreactivity. The rapid development of cytolytic hepatocellular necrosis and lobular collapse with prominent HBcAg immunoreactivity without significant inflammation suggests a cytolytic rather than immune pathogenesis for this unique and devastating form of recurrent hepatitis B that might better be termed "fibrosing cytolytic hepatitis."

Importance of precise determination of technetium-labeled DISIDA concentrations for in vitro hepatocellular transport studies

Technetium 99m-labeled diisopropyliminodiacetic (acid [99mTc]DISIDA) has been used extensively in the evaluation of hepatobiliary diseases. As a result of investigation into transport mechanisms of [99mTc]DISIDA, we undertook to determine precise concentrations of this compound in the standard clinical formulation. Calculations based on published formulas were used. These take into account column efficiency, the time since the previous elution of 99mTc from the 99Mo column, and the total quantity of 99mTc eluted. Primary cultures of rat hepatocytes were used to evaluate the transport of Na99mTcO4 and the 99mTc-labeled DISIDA monomer. Pertechnetate was not taken up by the hepatocytes, the amount of [99mTc]DISIDa taken up was not dependent on the concentration of DISIDA but rather on the concentration of technetium, when the DISIDA/99mTc ratio was varied in the culture medium. We conclude that calculation of the total technetium concentration is necessary to determine the amount of compound taken up by the liver, and to interpret kinetic studies of hepatocellular transport mechanisms.

The oncofetal gene Pem encodes a homeodomain and is regulated in primordial and pre-muscle stem cells

The oncofetal gene, Pem, is expressed in a stage specific manner during murine ontogeny. The carboxy terminal portion of the predicted Pem protein has significant similarity to homeodomains of the Drosophila prd family. The Pem gene is expressed in undifferentiated embryonal stem (ES) and embryonal carcinoma (EC) cell lines. Pem mRNA is induced 35-fold in ES cells differentiated in the absence of retinoic acid. Pem mRNA is increased in EC cells differentiated towards parietal or visceral endoderm, consistent with the abundant Pem expression in embryonic yolk sac. In 10T mesenchymal stem cells committed to muscle cell differentiation, Pem mRNA expression is dramatically increased. The elevation in Pem expression preceded the induction of the muscle master regulatory gene, myoD. We conclude that the Pem gene encodes a candidate transcription factor which is developmentally regulated.

Verapamil improves rat hepatic preservation with UW solution

Verapamil, a calcium channel blocker, improves myocardial preservation during cold cardioplegia and protects against renal damage during periods of warm and cold ischemia. To determine if verapamil could prevent ischemic damage to livers during and after cold storage, harvested rat livers were flushed with either University of Wisconsin (UW) solution or UW solution with 25 mg/liter verapamil. Twenty rats were used in each group. After 24 hr of storage at 4 degrees C, livers were perfused with oxygenated blood through the portal veins for 2 hr at 37 degrees C and pH 7.4. Liver enzymes, electrolytes, and perfusate flow rate were determined at 30-min intervals. At 90 min of perfusion, the verapamil group of livers had less elevation of AST (110 +/- 17 IU/liter vs 172 +/- 25 IU/liter, P less than 0.05), ALT (115 +/- 21 IU/liter vs 210 +/- 34 IU/liter, P less than 0.05), and LDH (962 +/- 170 IU/liter vs 1452 +/- 253 IU/liter, NS). Verapamil livers produced more bile than controls (6.9 +/- 1.9 microliters/g vs 2.3 +/- 1.7 microliter/g, P less than 0.05) and maintained a higher portal flow rate throughout the perfusion. Both groups showed similar reduction in liver weights after storage (3.9 +/- 0.9% vs 2.8 +/- 0.7%) and required the same amount of bicarbonate for correction of acidosis during perfusion (2.6 +/- 0.2 mM vs 2.8 +/- 0.2 mM). Light microscopic exam after perfusion showed hepatocyte damage in 30% of control livers, but 0% of verapamil livers. We conclude that verapamil-treated rat livers showed less damage and better function upon reperfusion after 24 hr of cold storage. This agent may be clinically useful as an additive to the UW preservation solution for livers.

Initial two-year results of the Oregon Liver Transplantation Program

During the first 24 months of the Oregon Liver Transplantation Program, which began in October 1988, 94 patients were formally evaluated and 47 adults underwent 54 liver transplantations. Thirty-four percent of patients were veterans. The recipient operation lasted a mean of 7.4 hours (range: 4 to 16 hours). Veno-venous bypass was used routinely at first but selectively later (7 of the last 26 cases), resulting in reduced operating time. Hepatic artery reconstruction was end-to-end anastomosis in 52 cases and iliac conduit in 2. No arterial thrombosis occurred. Biliary reconstruction was choledochocholedochostomy in 83% and choledochojejunostomy in 17%. Biliary complications occurred in 28%. Operative mortality was 2%, and 1-year actual survival was 80%. Patients with hepatitis B fared worse, with four of six dying at a mean of 7.6 months. Overall, the median hospital stay was 30 days. Patients surviving more than 3 months had a mean Karnofsky score of 82%. No significant difference in outcome was noted in patients receiving prophylactic OKT3 monoclonal antibody (used in 45%) versus conventional immunosuppressive therapy. Overall, allograft rejection occurred in 55% of patients. Retransplantation was required in seven patients, three for primary graft nonfunction, two for uncontrolled rejection during induction therapy with OKT3, and two for graft failure secondary to recurrent hepatitis B.

Mechanism of sucrose uptake by isolated rat hepatocytes

The transport of molecules by nonspecific endocytosis has been described in many cell types, but it has not been characterized in hepatocytes. Because of its central role in the clearance of solutes from portal blood, endocytosis might represent a significant mode of cellular transport. We investigated the mechanism of sucrose uptake in an isolated hepatocyte system. Liver cells were isolated by perfusion and collagenization of rat liver, followed by differential centrifugation. Hepatocytes were then incubated with 14C-sucrose and harvested by spinning through oil in microfuge tubes. Radioactivity was standardized against DNA content. We found that sucrose uptake is concentration-dependent from 5 microM to 100 mM and follows first-order kinetics. Washout studies indicate that exocytosis is responsible for the dynamic equilibrium reached. Arrhenius analysis of temperature dependence yields a linear plot (Ea = 14.2 Kcal/mol). In addition, sucrose uptake is independent of cellular ATP levels. We conclude that sucrose is transported by fluid-phase micropinocytosis in isolated hepatocytes and that this transport mechanism may be important in the uptake of diverse molecules into liver cells.