Soluble PD-L1 and Circulating CD8+PD-1+ and NK Cells Enclose a Prognostic and Predictive Immune Effector Score in Immunotherapy Treated NSCLC patients

INTRODUCTION

Upfront criteria to foresee immune checkpoint inhibitors (ICIs) efficacy are far from being identified. Thus, we integrated blood descriptors of pro-inflammatory/immunosuppressive or effective anti-tumor response to non-invasively define predictive immune profiles in ICI-treated advanced non-small cell lung cancer (NSCLC).

METHODS

Peripheral blood (PB) was prospectively collected at baseline from 109 consecutive NSCLC patients undergoing ICIs as first or more line treatment. Soluble PD-L1 (sPD-L1) (immunoassay), CD8+PD-1+ and NK (FACS) cells were assessed and interlaced to generate an Immune effector Score (I_effS). Lung Immune Prognostic Index (LIPI) was computed by LDH levels and derived Neutrophil-to-Lymphocyte Ratio (dNLR). All these parameters were correlated with survival outcome and treatment response.

RESULTS

High sPD-L1 and low CD8+PD-1+ and NK number had negative impact on PFS (P < 0.001), OS (P < 0.01) and ICI-response (P < 0.05). Thus, sPD-L1^high, CD8+PD-1+^low and NK^low were considered as risk factors encompassing I_effS, whose prognostic power outperformed that of individual features and slightly exceeded that of LIPI. Accordingly, the absence of these risk factors portrayed a favorable I_effS characterizing patients with significantly (P < 0.001) prolonged PFS (median NR vs 2.3 months) and OS (median NR vs 4.1) and greater benefit from ICIs (P < 0.01). We then combined each risk parameter composing I_effS and LIPI (LDH^high, dNLR^high), thus defining three distinct prognostic classes. A remarkable impact of I_effS-LIPI integration was documented on survival outcome (PFS, HR = 4.61; 95%CI = 2.32-9.18; P < 0.001; OS, HR=4.03; 95%CI=1.91-8.67; P < 0.001) and ICI-response (AUC=0.90, 95%CI=0.81-0.97, P < 0.001).

CONCLUSION

Composite risk models based on blood parameters featuring the tumor-host interaction might provide accurate prognostic scores able to predict ICI benefit in NSCLC patients.

Optimal processing of ESD specimens to avoid pathological artifacts

BACKGROUND

En bloc endoscopic submucosal dissection (ESD) has been recently introduced as a treatment for precancerous/neoplastic gastrointestinal conditions. The aim of the present study was histological assessment of en bloc ESD specimens.

METHODS

Fifty-three ESD specimens were positioned over a cellulose acetate support (40 specimens; 12 from the upper gastrointestinal tract and 28 from the lower gastrointestinal tract) or pinned with nails on polystyrene or cork (13 specimens; 7 from the upper gastrointestinal tract and 6 from the lower gastrointestinal tract). We cut consecutive 2 mm-thick sections stained with hematoxylin and eosin. From the first and the last sections, we obtained a second slide, after a 180° rotation and re-embedding. The quality of ESD samples was scored as inadequate, suboptimal and adequate, based on the amount of crushing, shearing and stretching artifacts that were scored from 0 (absent) to 2 (diffuse or maximum). From the sum of these we obtained a global artifact score (GAS).

RESULTS

Removed lesions were: adenocarcinoma (5 cases), neuroendocrine tumor (NET) G1 (1 case), premalignant conditions, including adenomatous polyps (41 cases) and hyperplastic lesions (6 cases). A positive deep surgical margin was found in 8/53 cases (15%): high- and low-grade dysplastic glands were detected in 5 cases, low-grade adenocarcinoma in 2, and NET cells in 1. Dysplastic glands were detected in the lateral surgical margins of 12 ESD specimens (23%). Among the ESD specimens positioned on the cellulose acetate support, apart from the modifications due to electrocoagulation, 2 (5%) showed shearing modifications. In the group of ESD specimens fixed with nails, 5 (38%) showed shearing, 10 (77%) crushing artifacts, 11 (85%) stretching and 11 (85%) multiple holes caused by the nails. On the basis of these data all histological specimens from ESD on cellulose acetate were adequate (GAS 0-1).However, in the group of ESD fixed with nails, 1 was adequate (GAS 0), 11 suboptimal (GAS 2-5) and 1 inadequate (GAS 6).

CONCLUSIONS

Specific devices including cellulose support and adequate sampling blocks can be helpful to perform accurate histological assessment of ESD specimens after en bloc ESD for precancerous/neoplastic gastrointestinal lesions, with complete analysis of the status of the margins and the entirely en bloc evaluation of the lesion.

The novel HBx mutation F30V correlates with hepatocellular carcinoma in vivo, reduces hepatitis B virus replicative efficiency and enhances anti-apoptotic activity of HBx N terminus in vitro

OBJECTIVE

We aimed to investigate HBx genetic elements correlated with hepatitis B virus (HBV) -related hepatocellular carcinoma (HCC) and their impact on (a) HBV replicative efficiency, (b) HBx binding to circular covalently closed DNA (cccDNA), (c) apoptosis and cell-cycle progression, and (d) HBx structural stability.

METHODS

This study included 123 individuals chronically infected with HBV: 27 with HCC (77.9% (21/27) genotype D; 22.1% (6/27) genotype A) and 96 without HCC (75% (72/96) genotype D; 25.0% (24/96) genotype A). HepG2 cells were transfected by wild-type or mutated linear HBV genome to assess pre-genomic RNA (pgRNA) and core-associated HBV-DNA levels, HBx-binding onto cccDNA by chromatin immunoprecipitation-based quantitative assay, and rate of apoptosis and cell-cycle progression by cytofluorimetry.

RESULTS

F30V was the only HBx mutation correlated with HCC (18.5% (5/27) in HCC patients versus 1.0% (1/96) in non-HCC patients, p 0.002); a result confirmed by multivariate analysis. In vitro, F30V determined a 40% and 60% reduction in pgRNA and core-associated HBV-DNA compared with wild-type (p <0.05), in parallel with a significant decrease of HBx binding to cccDNA and decreased HBx stability. F30V also decreased the percentage of apoptotic cells compared with wild-type (14.8 ± 6.8% versus 19.1 ± 10.1%, p <0.01, without affecting cell-cycle progression) and increased the probability of HBx-Ser-31 being phosphorylated by PI3K-Akt kinase (known to promote anti-apoptotic activity).

CONCLUSIONS

F30V was closely correlated with HBV-induced HCC in vivo, reduced HBV replicative efficiency by affecting HBx-binding to cccDNA and increased anti-apoptotic HBx activity in vitro. This suggests that F30V (although hampering HBV's replicative capacity) may promote hepatocyte survival, so potentially allowing persistent production of viral progeny and initiating HBV-driven hepatocarcinogenesis. Investigation of viral genetic markers associated with HCC is crucial to identify those patients at higher risk of HCC, who hence deserve intensive liver monitoring and/or early anti-HBV therapy.

Years of life that could be saved from prevention of hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) causes premature death and loss of life expectancy worldwide. Its primary and secondary prevention can result in a significant number of years of life saved.

AIM

To assess how many years of life are lost after HCC diagnosis.

METHODS

Data from 5346 patients with first HCC diagnosis were used to estimate lifespan and number of years of life lost after tumour onset, using a semi-parametric extrapolation having as reference an age-, sex- and year-of-onset-matched population derived from national life tables.

RESULTS

Between 1986 and 2014, HCC lead to an average of 11.5 years-of-life lost for each patient. The youngest age-quartile group (18-61 years) had the highest number of years-of-life lost, representing approximately 41% of the overall benefit obtainable from prevention. Advancements in HCC management have progressively reduced the number of years-of-life lost from 12.6 years in 1986-1999, to 10.7 in 2000-2006 and 7.4 years in 2007-2014. Currently, an HCC diagnosis when a single tumour <2 cm results in 3.7 years-of-life lost while the diagnosis when a single tumour ≥ 2 cm or 2/3 nodules still within the Milan criteria, results in 5.0 years-of-life lost, representing the loss of only approximately 5.5% and 7.2%, respectively, of the entire lifespan from birth.

CONCLUSIONS

Hepatocellular carcinoma occurrence results in the loss of a considerable number of years-of-life, especially for younger patients. In recent years, the increased possibility of effectively treating this tumour has improved life expectancy, thus reducing years-of-life lost.

Comparison between alcohol- and hepatitis C virus-related hepatocellular carcinoma: clinical presentation, treatment and outcome

BACKGROUND

Hepatitis C virus (HCV) and alcohol abuse are the main risk factors for hepatocellular carcinoma (HCC) in Western countries.

AIM

To investigate the role of alcoholic aetiology on clinical presentation, treatment and outcome of HCC as well as on each Barcelona Clinic Liver Cancer (BCLC) stage, as compared to HCV-related HCCs.

METHODS

A total of 1642 HCV and 573 alcoholic patients from the Italian Liver Cancer (ITA.LI.CA) database, diagnosed with HCC between January 2000 and December 2012 were compared for age, gender, type of diagnosis, tumour burden, portal vein thrombosis (PVT), oesophageal varices, liver function tests, alpha-fetoprotein, BCLC, treatment and survival. Aetiology was tested as predictor of survival in multivariate Cox regression models and according to HCC stages.

RESULTS

Cirrhosis was present in 96% of cases in both groups. Alcoholic patients were younger, more likely male, with HCC diagnosed outside surveillance, in intermediate/terminal BCLC stage and had worse liver function. After adjustment for the lead-time, median (95% CI) overall survival (OS) was 27.4 months (21.5-33.2) in alcoholic and 33.6 months (30.7-36.5) in HCV patients (P = 0.021). The prognostic role of aetiology disappeared when survival was assessed in each BCLC stage and in the Cox regression multivariate models.

CONCLUSIONS

Alcoholic aetiology affects survival of HCC patients through its negative effects on secondary prevention and cancer presentation but not through a greater cancer aggressiveness or worse treatment result. In fact, survival adjusted for confounding factors was similar in alcoholic and HCV patients.

Interleukin 28B polymorphisms as predictors of sustained virological response in chronic hepatitis C: systematic review and meta-analysis

Polymorphism of interleukin 28B gene represents a powerful outcome predictor for interferon-based regimens in hepatitis C virus infection. However, some studies report conflicting results. The predictive value of interleukin 28B genotype over the outcome interferon-α/ribavirin treatment was thoroughly evaluated and compared with virological predictors of response. Literature revision was performed on PubMed. Pooled odds ratios (ORs) were calculated by fixed- or random-effects models. Heterogeneity and publication bias were also assessed. Sixty-two eligible papers including 20 290 patients were retrieved. Both polymorphisms (rs12979860 and rs8099917) were strongly associated with response (OR=4.09 and 4.00, respectively), however, the association was weaker for subjects infected with viral genotypes 2 and 3 (OR=1.52 and 1.49, respectively). Compared with interleukin 28B genotype, the association with response was lower for baseline viremia (OR=2.15) and higher for rapid virological response (OR=13.86). These results provide a critical evaluation of interleukin 28B genotype as a pharmacogenetic predictor in hepatitis C patients.

L-Asparaginase and inhibitors of glutamine synthetase disclose glutamine addiction of β-catenin-mutated human hepatocellular carcinoma cells

Selected oncogenic mutations support unregulated growth enhancing glutamine availability but increasing the dependence of tumor cells on the amino acid. Data from literature indicate that a subset of HepatoCellular Carcinomas (HCC) is characterized by mutations of β-catenin and overexpression of Glutamine Synthetase (GS). To assess if this phenotype may constitute an example of glutamine addiction, we treated four human HCC lines with the enzyme L-Asparaginase (ASNase), a glutaminolytic drug. ASNase had a significant antiproliferative effect only in the β-catenin mutated HepG2 cells, which were partially rescued by the anaplerotic intermediates pyruvate and α-ketoglutarate. The enzyme severely depleted cell glutamine, caused eIF2α phosphorylation, inhibited mTOR activity, and increased autophagy in both HepG2 and in the β-catenin wild type cell line Huh-7. When used with ASNase, the GS inhibitor methionine sulfoximine (MSO) emptied cell glutamine pool, arresting proliferation in ASNase-insensitive Huh-7 cells and activating caspase-3 and apoptosis in HepG2 cells. Compared with Huh-7 cells, HepG2 cells accumulated much higher levels of glutamine and MSO, due to the higher expression and activity of SNAT2, a concentrative transporter for neutral amino acids, but were much more sensitive to glutamine withdrawal from the medium. In the presence of ASNase, MSO caused a paradoxical maintenance of rapamycin-sensitive mTOR activity in both HepG2 and Huh-7 cells. β-catenin silencing lowered ASNase sensitivity of HepG2 cells and of Huh-6 cells, another β-catenin-mutated cell line, which also exhibited high sensitivity to ASNase. Thus, β-catenin mutated HCC cells are more sensitive to glutamine depletion and accumulate higher levels of GS inhibitors. These results indicate that glutamine deprivation may constitute a targeted therapy for β-catenin-mutated HCC cells addicted to the amino acid.

Percutaneous ultrasound-guided radiofrequency ablation of an allograft renal cell carcinoma: a case report

BACKGROUND

Renal cell carcinomas (RCCs) are rarely described in transplanted kidneys. Available therapeutic strategies range from allograft nephrectomy to nephron-sparing procedures such as partial nephrectomy or image-guided thermal ablation. Percutaneous radiofrequency ablation (RFA) is a minimally invasive technique which provides promising oncologic outcomes in small allograft RCCs while preserving allograft function. So far, only a few cases have been reported in the transplant setting. We describe a renal transplant RCC successfully approached by ultrasound-guided RFA.

METHODS

A 42-year-old renal transplant recipient developed a small subcapsular allograft RCC at 11 years after transplantation. The decline in glomerular filtration rare prompted us to preserve as much parenchyma as possible. Ultrasound-guided RFA was performed under light sedation and local analgesia in a single session with a Starbust Talon needle.

RESULTS

Postablation contrast-enhanced ultrasound displayed a 25×23 mm avascular area of complete necrosis. After 3 months gadolinium-enhanced magnetic resonance imaging confirmed the absence of viable tumor tissue and while the patient did not experience any graft function reduction (serum creatinine 2.6 mg/dL).

CONCLUSIONS

Image-guided RFA represents a promising therapeutic modality for small allograft RCCs in recipients with mild graft dysfunction and/or elevated surgical risk. It is associated with low morbidity and parenchymal preservation.

IL28B polymorphisms predict reduction of HCV RNA from the first day of therapy in chronic hepatitis C

BACKGROUND & AIMS

Single nucleotide polymorphisms (SNPs) associated with IL28B influence the outcome of peginterferon-α/ribavirin therapy of chronic hepatitis C virus (HCV) infection. We analyzed the kinetics of HCV RNA during therapy as a function of IL28B SNPs.

METHODS

IL28B SNPs rs8099917, rs12979860, and rs12980275 were genotyped in 242 HCV treatment-naïve Caucasian patients (67% genotype 1, 28% genotype 2 or 3) receiving peginterferon-α2a (180 μg weekly) and ribavirin (1000-1200 mg daily) with serial HCV-RNA quantifications. Associations between IL28B polymorphisms and early viral kinetics were assessed, accounting for relevant covariates.

RESULTS

In the multivariate analyses for genotype 1 patients, the T allele of rs12979860 (T(rs12979860)) was an independent risk factor for a less pronounced first phase HCV RNA decline (log(10) 0.89IU/ml among T carriers vs. 2.06 among others, adjusted p < 0.001) and lower rapid (15% vs. 38%, adjusted p = 0.007) and sustained viral response rates (48% vs. 66%, adjusted p < 0.001). In univariate analyses, T(rs12979860) was also associated with a reduced second phase decline (p = 0.002), but this association was no longer significant after adjustment for the first phase decline (adjusted p = 0.8). In genotype 2/3 patients, T(rs12979860) was associated with a reduced first phase decline (adjusted p = 0.04), but not with a second phase decline.

CONCLUSIONS

Polymorphisms in IL28B are strongly associated with the first phase viral decline during peginterferon-α/ribavirin therapy of chronic HCV infection, irrespective of HCV genotype.

Early kinetics of innate and adaptive immune responses during hepatitis B virus infection

BACKGROUND AND AIMS

Innate immunity appears to be silent in acutely hepatitis B virus (HBV)-infected chimpanzees, as shown by microarray analysis of intrahepatic gene expression. Whether this observation also applies to HBV pathogenesis in man remains undefined. The aim of this study was thus to characterise natural killer (NK) and CD56(+) natural T (NT) cell responses early after human HBV infection and their relationship to the induction of adaptive immunity.

METHODS

Two HBV-seronegative blood donors who became hepatitis B surface antigen (HBsAg) and HBV DNA positive but had persistently normal alanine aminotransferase (ALT) were followed from a very early stage of HBV infection. The phenotype (CD69 and NKG2D) and function (cytotoxicity and interferon gamma (IFN gamma) production) of NK and NT cells were analysed. CD4- and CD8-mediated responses were studied in parallel with overlapping peptides covering the entire HBV sequence by ex vivo intracellular cytokine staining (ICS) for IFN gamma, interleukin 2 (IL2), IL4 and IL10, and by ex vivo Elispot for IFN gamma. Healthy subjects, and patients with chronic and acute HBV infection were studied for comparison.

RESULTS

An early induction of both innate and adaptive responses was observed. NK and NT cells showed faster kinetics than HBV-specific T cells with an earlier peak of activity, while CD4(+) and CD8(+) cell responses were mounted with a similar profile, with higher frequencies of IFN gamma-producing CD8(+) cells at the peak of the response.

CONCLUSIONS

The innate immune system is able to sense HBV infection, as shown by the early development of NK and NT cell responses, which probably contribute to contain the HBV infection and to allow timely induction of adaptive responses.

Targeted therapy with trastuzumab in dysplasia and adenocarcinoma arising in Barrett's esophagus: a translational approach

AIM

Human epidermal growth factor receptor (HER2) protooncogene, overexpressed/ amplified in preneoplastic lesions and in adenocarcinoma (ADC) of the esophagus, can be considered a target for treatment of esophageal dysplasia/ADC. The aim of this study was to evaluate the therapeutic role of the anti-HER2 monoclonal antibody, trastuzumab, in the management of ADC originating from HER2-positive Barrett's esophagus (BE).

METHODS

Two patients with high-grade dysplasia and ADC of the esophagus after esophageal mucosectomy and no metastatic disease were studied. Patients were not eligible for radical surgery or chemo-radiotherapy because of age and comorbidities. HER2 status was assessed by immunohistochemistry and fluorescence in situ hybridization. Additional immunohistochemical analyses were performed. The whole panel was analysed at baseline, after treatment and at follow-up.

RESULTS

At baseline, the two patients showed HER-2 overexpression/amplification in all areas of dysplasia and ADC but not in BE. Six months after treatment no significant differences in terms of endoscopical and histological patterns of the disease were found. HER-2, EGFR, TOPOII-alpha and anti-ssDNA analysis demonstrated a down-regulation of these markers and increased apoptosis.

CONCLUSION

This study demonstrates that this treatment is feasible. No clear evidence of dysplasia regression was observed. However, HER2 and TopoII-alpha downregulation and induction of apoptosis occurring 6 months after treatment encourages further investigation.

COX-2, CDX2, and CDC2 immunohistochemical assessment for dysplasia-carcinoma progression in Barrett's esophagus

BACKGROUND

Immunohistochemical changes associated with development of cancer in Barrett's esophagus offer potential areas of intervention to prevent and manage esophageal cancer.

AIMS

To assess the role of cyclooxygenase 2, caudal-type homeobox transcription factor 2 and cell division cycle 2/cyclin-dependent kinase 1 in the Barrett's metaplasia-dysplasia-adenocarcinoma sequence.

PATIENTS AND METHODS

Specimens from 46 patients with Barrett's esophagus (39% without dysplasia, 33% with dysplasia and 28% with adenocarcinoma) were stained for cyclooxygenase 2, caudal-type homeobox transcription factor 2 and cell division cycle 2.

RESULTS

Cyclooxygenase 2: No expression differences between groups were found, except for adenocarcinomas (p=0.04). Caudal-type homeobox transcription factor 2: Nuclear positivity decreased from Barrett's esophagus without dysplasia (71.6%), to Barrett's esophagus with low grade dysplasia (35.3%), to Barrett's esophagus with high grade dysplasia (17.14%); in adenocarcinoma these percentages were intermediate between high and low grade dysplasia (30.5%). Cell division cycle 2: Expression on deeper glandular structures was 40% in Barrett's esophagus without dysplasia, 55.47% in Barrett's esophagus with dysplasia, and 63.84% in adenocarcinoma, with no statistical differences between groups. Concerning cells of the superficial layer, Barrett's esophagus with low grade dysplasia expressed focal positivity (p=0.0001 vs. no dysplasia); Barrett's esophagus with high grade dysplasia displayed diffuse positivity (p=0.0001 vs. no dysplasia and low grade dysplasia). A diffuse positivity was found in Barrett's esophagus with adenocarcinoma (p=0.0001 vs. no dysplasia and low grade dysplasia).

CONCLUSIONS

Further evaluation of cyclooxygenase 2, cell division cycle 2 and caudal-type homeobox transcription factor 2, in association with morphology, might help to improve the accuracy of diagnosis and be useful for the clinical-pathological assessment of patients with Barrett's esophagus.

Screening for and surveillance of Barrett's esophagus is clinically indicated

Barrett's esophagus (BE) is a complication of chronic gastroesophageal reflux disease (GERD) and is the precursor of esophageal adenocarcinoma (EA), through a progression from intestinal metaplasia (IM), through high-grade dysplasia (HGD). Although the progression from BE to EA seems to be infrequent (0.5% per year), endoscopic and bioptic surveillance would play a significant role in the evaluation of HGD and the detection of EA in early, curable stage, improving survival rates after treatments. The severity and the duration of GERD could be helpful in the assessment of the risk for BE and to enroll these subjects into screening protocols to detect any dysplastic or neoplastic change. The benefits of screening-surveillance programs could be furthermore enhanced by an improvement in diagnostic methods, such as high-resolution endoscopic techniques and the use of biomarkers for the histological examination seems to play a primary role in the cancer risk stratification; in such way, endoscopic resection techniques (mucosal resection and submucosal dissection) can be considered as a helpful method to stage dysplastic changes in BE.

Impact of hepatic steatosis on viral kinetics and treatment outcome during antiviral treatment of chronic HCV infection

Liver steatosis is highly prevalent in chronic hepatitis C virus (HCV) infection, especially in patients infected with genotype 3 virus, but its significance for the outcome of antiviral treatment is not fully understood. We have monitored steatosis in liver biopsies from 231 patients with chronic HCV infection who received pegylated recombinant interferon-alpha and ribavirin in a phase III study (DITTO trial). The degree of steatosis, along with relevant metabolic parameters, was correlated with the early disappearance of virus and with the final outcome of treatment. Our data suggest that the presence of steatosis impairs the early reduction of viral load during treatment in patients infected with HCV genotype 3 and non-3. Steatosis negatively affected the final outcome of treatment mainly in patients infected with HCV genotype non-3 virus. Based on these findings, we propose that interventions aiming at reducing hepatic steatosis prior to the onset of antiviral therapy may be of benefit to patients infected with HCV of the non-3 genotypes. Patients infected with genotype 3, on the other hand, should be offered early antiviral treatment.

Immunoglobulin G fragment C receptor polymorphisms and response to trastuzumab-based treatment in patients with HER-2/neu-positive metastatic breast cancer

13090

Background: A potential mechanism of action of the humanized anti-HER-2/neu monoclonal antibody Trastuzumab involves antibody-dependent cellular cytotoxicity (ADCC) with the activation of immune effector cells via their immunoglobulin G fragment C receptors (FcγRs). Trastuzumab has been shown to engage both activation (FcγRIIIa; FcγRIIa) and inhibitory (FcγRIIb) antibody receptors on myeloid cells and several FcγR polymorphisms have been identified that may affect the antibody-dependent cytotoxicity of natural killer cells and macrophages. Methods: Forty consecutive HER-2/neu-positive (FISH+) metastatic breast cancer patients receiving a trastuzumab-based treatment (combined with paclitaxel for the majority) were examined for the FcγRIIIa 158 valine (V)/phenylalanine (F), FcγRIIa 131 histidine (H)/arginine (R), and FcγRIIb 232 isoleucine (I)/threonine (T) polymorphisms. A PCR-RFLP based assay using genomic DNA was performed for FcγRIIIa and FcγRIIa genotyping, while PCR-SSCP methods using complementary DNA were utilized for FcγRIIb. Patients’ peripheral blood mononuclear cells were drawn before treatment initiation and their trastuzumab-mediated killing function was measured by 51Cr release using a HER-2/neu-expressing human breast cancer cell line as a target. The results were then correlated with clinical outcome of these patients. Results: Median age was 60 years (range 26–83 years). Thirty-six (90%) patients received a trastuzumab-based treatment as first-line therapy. The overall clinical benefit rate (CR+PR+SD) was 65% (95% Confidence Interval: 62–71%), including 8 (20%) complete and 11 (27.5%) partial responses. Median survival was 22.3 mo with a median PFS of 7 mo. Trastuzumab-based treatment was well tolerated and no changes in cardiac function were observed. Conclusions: This study evaluates for the first time the potential role of FcγR polymorphisms in predicting response to trastuzumab-based treatment. Results according to this study purpose will be presented at the meeting.

No significant financial relationships to disclose.

Is there a role for immunotherapy in hepatocellular carcinoma?

Incidence of hepatocellular carcinoma has been rising in the last two decades because of the wide exposure to hepatitis C virus during 1960s and 1970s. Improvement in treatment has been achieved by local ablative therapies, however because of early recurrence and lack of effective chemotherapies, alternative treatments based on stimulation of the anti-tumour immune response could represent new strategies to control hepatocellular carcinoma spread and recurrence. Proof of principle of an effective immunotherapy has been achieved for other solid tumours such as melanoma and several results could be transferred to the immunotherapy of hepatocellular carcinoma. Specific tumour antigens have been identified in hepatocellular carcinoma, such as cancer testis antigens expressed in a large part of hepatocellular carcinomas and alpha-fetoprotein that has been already employed in clinical trials demonstrating immunogenicity without however significant clinical efficacy. Better results have been achieved by non-antigen-specific immunotherapies that demonstrated improvement in recurrence and recurrence-free survival in patients undergoing surgical resection for hepatocellular carcinoma. Passive immunotherapy and targeted therapies blocking tumour cell receptors or enzymatic pathways are already in the clinic for other malignancies and the near future will see these new treatments applied to hepatocellular carcinoma patients along with the development of efficacious active immunotherapies aimed at reducing disease recurrence and improving survival.

Immunological markers anti-saccharomyces cerevisiae antibodies (ASCA) and anti-neutrophil cytoplasmic antibodies (ANCA) in inflammatory bowel disease: a helpful diagnostic tool

AIM

Nowadays the diagnosis of inflammatory bowel disease (IBD) and the differentiation between Crohn disease (CD) and ulcerative colitis (UC) is still based on morphological changes identified at endoscopy, radiology, and histopathology. In 5-15% of cases this differentiation is not possible (diagnosed with indeterminate colitis).

METHODS

We evaluated if recently developed commercial kits for the determination of anti-Saccharomyces Cerevisiae antibodies (ASCA) and anti-neutrophil cytoplasmic antibodies (ANCA) are useful in differentiating cases of UC from CD diseases with a consequent reduced number of undefined colitis and improved clinical management. Sera from 56 consecutive patients with a clinical diagnoses of IBD were evaluated in a blinded fashion for the presence of ASCA IgA and IgG and ANCA IgG with 2 different diagnostic methods: indirect immunofluorescence (IIF) and enzyme-linked immunosorbent assay (ELISA).

RESULTS

In our cases we observed good agreement between histopathological examination and laboratory results and the combined use of ASCA and ANCA yielded a correct diagnosis in 93% of patients with CD and in 97% of the UC patients.

CONCLUSIONS

We confirm the value of the test for the diagnosis of CD and UC and the differentiation from other forms of colitis.

Role of viral and host factors in HCV persistence: which lesson for therapeutic and preventive strategies?

Several lines of evidence support the view that hepatitis C virus is not directly cytopathic for infected host cells and that the immune response plays a central role in the pathogenesis of liver damage. Innate and adaptive immune responses are induced in most individuals infected with hepatitis C virus but are insufficient to eliminate the virus. The mechanisms responsible for this failure are largely unknown but the kinetics of hepatitis C virus replication relative to the priming of the adaptive responses may exert a profound influence on the balance between virus and host. Immediately after hepatitis C virus infection, the virus replicates efficiently, inducing the production of type I interferons. However, the rapid increase in viral replication seems to be ignored by the adaptive immune response, and after a short interval from exposure, viral load can reach levels comparable to those of patients with established persistent infection. The CD8-mediated response shows functional defects, with impaired production of interferon-gamma, low perforin content, decreased capacity of expansion and lysis of target cells. Late appearance and functional defects of T cells in hepatitis C virus infection might be the result of the rapid increase of the viral load that could create the conditions for exhaustion of the adaptive response or reflect an insufficient function of the innate immune response. This possibility is suggested by in vitro studies showing that hepatitis C virus gene products can interfere with the anti-viral activity of type I interferons and natural killer cells as well as with the maturation of dendritic cells. While T-cell defects are reversed in a minority of infected individuals who succeed in controlling the infection, the T-cell impairment becomes progressively more profound as infection progresses to chronicity. In this situation, therapeutic restoration of adaptive responses may represent a rational strategy to obtain resolution of infection and to complement available therapies. The peculiar kinetics of hepatitis C virus replication and T-cell induction soon after infection may have important implications also for the design of protective vaccines since memory responses may not be able to precede the early peak of viral replication. Therefore, vaccines against hepatitis C virus may be unable to prevent infection but may rather be effective in facilitating a self-limited evolution of infection.

Dilated intercellular spaces as markers of reflux disease: histology, semiquantitative score and morphometry upon light microscopy

BACKGROUND AND AIMS

A recent electron microscopy study suggested that dilated intercellular spaces (DIS) are specific for acid reflux-damaged esophageal epithelium. Electron microscopy is, however, expensive and difficult to apply to routine biopsies. The aims of this study are to establish a method for assessing DIS on light microscopy of esophageal biopsies and to estimate its association with current clinicopathological parameters of esophagitis.

MATERIALS AND METHODS

21 patients with reflux symptoms were investigated. Light microscopy biopsies were assessed for DIS size by a semiquantitative method and computer-assisted, static morphometry. A DIS score accounting for DIS size and distribution was assigned to each patient and its association with 30 clinicopathological variables investigated by univariate and multivariate logistic regression.

RESULTS

Both the semiquantitative method and static morphometry identified 4 different classes of DIS size. The DIS score was significantly and independently associated with the esophageal symptoms score, the histological score of esophagitis and the relevant morphometry data.

CONCLUSIONS

DIS may be efficiently assessed during light microscopy of routine esophageal biopsies. Since correlation with both the histology and the symptoms of esophagitis, the DIS score may be considered a novel parameter of esophagitis and is suggested for the routine evaluation of esophageal biopsies in patients with reflux disease.

[Intestinal brushing. Technical-cytological contribution in the pathological study of Vater's ampulla, common bile duct, and pancreatic system]

OBJECTIVE

This experience shows the effectiveness of the cytological examination in the diagnosis of biliary and pancreatic neoplasm on samples obtained from Vater's papilla through endoscopic intestinal brushing.

STUDY DESIGN

From June 1997 to October 1998, 28 patients, suffering from suspicious neoplasm of Vater's papilla or biliary system, were studied. Each sample was obtained through intestinal brushing during an Endoscopic Retrograde Colangio-Pancreatography (ERCP) and processed with the technique of direct smear stained with Papanicolaou's method. The sample was followed by the corresponding biopsy in 16 cases and by surgical specimens in 8 cases.

RESULTS

27 patients out of 28 were correctly classified by the intestinal brushing. The method carried out a positive predictive value of 100% and a sensitivity of 93%. The sensitivity of biopsy turned out to be 80%.

CONCLUSIONS

The intestinal brushing is an effective method of diagnosis, which turned out to be relevant as a support and, in several cases, as a substitute of the biopsy. We think, therefore, that the brushing should be carried out whenever a lesion of the Vater's papilla or of the biliary system is suspected during an ERCP.

Conserved hepatitis C virus sequences are highly immunogenic for CD4(+) T cells: implications for vaccine development

The HLA class II-restricted T-cell response to hepatitis C virus (HCV) antigens is believed to influence the final outcome of hepatitis C, because it is vigorous in patients who recover from acute hepatitis C, but it is weak in those who develop a chronic infection. For this reason, exogenous stimulation of T-cell responses in chronic HCV infection may represent a strategy to cure patients with chronic hepatitis C by approximating the vigor of their T-cell reactivity to that of patients who succeed in recovering from hepatitis. It may also be a preventive approach to avoid spread of the virus by facilitating the development of a vigorous protective response at the very early stages of infection. T-cell-based vaccines composed of immunodominant, promiscuous, and conserved T-cell epitopes may represent a powerful tool to achieve optimal stimulation of the T-cell reactivity. To identify HLA class II-restricted T-cell epitopes useful for this purpose, 22 subjects with acute HCV infection were studied and followed for an average time of 29 months. Eight of them recovered from hepatitis, and 14 developed a chronic infection. Overlapping 20-mer peptides covering the entire core and NS4 antigens and a panel of peptides representing highly conserved regions of core, NS3, NS4, and NS5 were used. By direct peripheral blood T-cell stimulation and by fine-specificity analysis of HCV-specific T-cell lines and clones, highly immunogenic T-cell epitopes were identified within core, NS3, and NS4. All these epitopes are immunodominant and highly conserved among the known HCV isolates. Moreover, they are promiscuous, because they can be presented to T cells by different HLA class II molecules. Immunodominance, sequence conservation, and promiscuity make these epitopes ideal components of preventive or therapeutic T-cell-based vaccines against HCV.

Antibody responses to hepatitis C virus hypervariable region 1: evidence for cross-reactivity and immune-mediated sequence variation

Sequence heterogeneity of hepatitis C virus (HCV) is unevenly distributed along the genome, and maximal variation is confined to a short sequence of the HCV second envelope glycoprotein (E2), designated hypervariable region 1 (HVR1), whose biological function is still undefined. We prospectively studied serological responses to synthetic oligopeptides derived from HVR1 sequences of patients with acute and chronic HCV infection obtained at baseline and after a defined follow-up period. Extensive serological cross-reactivity for unrelated HVR1 peptides was observed in the majority of the patients. Antibody response was restricted to the IgG1 isotype and was focused on the carboxyterminal end of the HVR1 region. Cross-reactive antibodies could be readily elicited following immunization of mice with multiple antigenic peptides carrying HVR1 sequences derived from our patients. The vigor and heterogeneity of cross-reactive antibody responses were significantly higher in patients with chronic hepatitis compared with those with acute hepatitis and in patients infected with HCV type 2 compared with patients infected with other viral genotypes (predominantly type 1), which suggest that higher time-related HVR1 sequence diversification previously described for type 2 may result from immune selection. The finding of a statistically significant correlation between HVR1 sequence variation, and intensity, and cross-reactivity of humoral immune responses provided stronger evidence in support of the contention that HCV variant selection is driven by the host's immune pressure.

Antiviral cell-mediated immune responses during hepatitis B and hepatitis C virus infections

Cell-mediated immune responses to hepatitis B (HBV) and hepatitis C virus (HCV) antigens are vigorous and multispecific in acute, self-limited infections. Moreover, the prevalent cytokine pattern of circulating virus-specific T cells from patients who recover spontaneously from acute hepatitis is Th1-like. Longitudinal analysis of the T cell response to HCV antigens from the early stages of HCV infection in patients who recover from hepatitis and those who do not indicates that weaker responses and a prevalent Th2 pattern of cytokine production is associated with viral persistence and chronic evolution of disease. Although similar sequential studies are missing in hepatitis B, the observation that HBV-specific T cell responses are very weak or totally undetectable in the peripheral blood of patients with long-lasting chronic hepatitis B suggests that strength and quality of virus-specific T cell responses at the early stages of infection may influence the final outcome of both hepatitis B and C. While T cell hyporesponsiveness seems to be an important determinant for HBV persistence once chronic hepatitis has developed, this mechanism appears to be less critical in chronic HCV infection, because the vigor and quality of HCV-specific T cell responses seem to improve as a function of the duration of infection. This is shown by the finding that HCV-specific CD4- and CD8-mediated responses are easily detectable in the peripheral blood of patients with long-lasting chronic hepatitis C and that production of Th1 cytokines predominates within their livers. HCV therefore seems to be able to persist even in the face of an active T cell response and to acquire the capacity to survive within a host environment apparently unfavorable to its persistence. The high variability of HCV may explain its efficiency in escaping immune surveillance.

[Flow cytometry sutdy of DNA and cell kinetics in the adenoma- carcinoma sequence in the large intestine]

The quantitation of DNA and growth fraction in the different step from dysplastic to neoplastic process in large bowel is the aim of this study. 70 colonic polyps were studied. The fresh specimens were processed and DNA analysis was carried out using a Partec CA II flow cytometer and the growth fraction was tested with KI-67 monoclonal antibody. The percentage of S-phase cells has been calculated with the Multicycle program. Our results demonstrated that 7 adenomas were tubulo-villous with mild dysplasia, 39 with mild-moderate dysplasia, 1 with severe dysplasia, 5 were polypoid carcinomas, 2 juvenile polyps, 1 polypoid leiomyoma, 1 inflammatory fibroid polyps. DNA analysis showed a diploid DNA content in non adenomatous polyps, in all adenomas with mild dysplasia, in 37 with mild-moderate dysplasia, in 8 cases with moderate-severe dysplasia and 1 cancer. Aneuploidy was discovered in 2 cases with mild-moderate dysplasia, in 6 cases with moderate-severe dysplasia, in the case of severe dysplasia and in 4 cases of carcinomas. Best indexes of linear correlation (Pearson's r) has been found between S-phase and DNA index (r = .75) and between S-phase and KI-67 (r = .82).

IN CONCLUSION

1) No relationship was found between DNA content and age, sex, size and location of polyps. 2) Aneuploidy is strictly related to moderate-severe grade of dysplasia therefore it is an important element in the development of adenomacarcinoma sequence. 3) DNA-index, S-phase and KI-67 are strictly related.

Effects of interferon treatment on the antiviral T-cell response in hepatitis C virus genotype 1b- and genotype 2c-infected patients

The viral genotype may influence the response to interferon (IFN) treatment in chronic hepatitis C virus (HCV) infection. To characterize potential mechanisms responsible for this effect, we assessed whether IFN modulation of HCV-specific T-cell responses differs in patients infected by different genotypes. The T-cell response to HCV core protein was sequentially analyzed before and during IFN treatment in two groups of patients chronically infected with HCV genotype 1b (eight patients) or 2c (eight patients). Overlapping 20 mer peptides corresponding to the amino acid sequence of the prevalent viral population identified in the serum of each patient were used for the analysis of the T-cell proliferative response to avoid possible problems caused by amino acid differences between infecting virus and HCV proteins used in vitro. Recombinant HCV core antigen was used in parallel. The level of viremia was monitored by competitive polymerase chain reaction (PCR). The T-cell response to HCV peptides and recombinant core protein detected throughout the follow-up was significantly more vigorous in genotype 2c- than in genotype 1b-infected patients. This difference was the result of a greater enhancement of the T-cell response caused by IFN treatment in genotype 2c- compared with genotype 1b-infected patients. The different IFN modulatory effect on T cells from genotype 1b- and genotype 2c-infected patients illustrates an aspect of the virus-host interaction, which may contribute toward the explanation of why different genotypes differ in responsiveness to IFN treatment.

Different cytokine profiles of intraphepatic T cells in chronic hepatitis B and hepatitis C virus infections

BACKGROUND & AIMS

The cytokine pattern secreted by T cells at the site of viral replication may influence the final outcome of hepatitis B virus (HBV) and hepatitis C virus (HCV) infections. The aim of this study was to assess whether a cytokine imbalance oriented toward T helper (Th) 1 or Th2-type responses may play a role in chronic hepatitis B or C.

METHODS

Production of interferon (IFN)-gamma, interleukin (IL)-4, and IL-5 by wide series of T-cell clones derived from the liver of 6 patients with chronic hepatitis B (291 clones) and 9 patients with chronic hepatitis C (260 clones) was studied. T-cell clones were generated by limiting dilution from freshly isolated mononuclear cells derived from liver tissue to give a reliable representation of the intrahepatic inflammatory infiltrates.

RESULTS

The majority of liver-infiltrating T cells in chronic hepatitis C were Th1 cells able to secrete IFN-gamma but unable to secrete IL-4 or IL-5, whereas in hepatitis B, most CD4+ and CD8+ liver T cells were ThO-like cells able to produce not only IFN-gamma but also IL-4 and IL-5.

CONCLUSIONS

The different cytokine profiles of T cells within the liver in chronic HBV and HCV infections illustrate a different behavior of the local immune response in these two infections that may have pathogenetic implications.

Digestive endoscopy and portal hypertension. North Italian Endoscopic Club

Improved knowledge of pathophysiology of portal hypertension and technological progress have contributed to development of new endoscopic techniques and pharmacological approaches to treatment of this condition. To put the role of endoscopy in the right perspective, it is important to consider that liver transplantation has greatly modified prognosis of cirrhosis. Because of the increase of indications for transplantation, these complications are no longer regarded as the last, but rather as an intermediate stage before a possible transplantation. We have reviewed some pathophysiologic, diagnostic and therapeutic aspects on portal hypertension, especially the role of endoscopy in diagnosis, natural history and therapeutic options for complications of cirrhosis. In addition to sclerotherapy, new endoscopic methods have been developed, with a low complication rate and possibility of being applied for treatment of gastric varices, i.e. injection of tissue adhesives and rubber band ligation. Besides oesophageal varices, gastric varices and portal hypertensive gastropathy (and portal colopathy) are important findings in cirrhosis. Further information is needed on natural history and treatment of these conditions. Digestive haemorrhage is the most important consequence of portal hypertension, so treatment should be aimed at controlling acute bleeding, rebleeding and, more important, at preventing first haemorrhagic episode. Good results will probably be obtained using a combination of drugs, a combination of endoscopic methods or a combination of both. All will need evaluation in randomised, controlled trials. These considerations renew interest in strategies for diagnosis and treatment of portal hypertension and a multidisciplinary approach may be necessary, involving gastroenterologists, endoscopists, interventionist radiologists and surgeons, ideally in a departmental environment.

Different clinical behaviors of acute hepatitis C virus infection are associated with different vigor of the anti-viral cell-mediated immune response

The anti-viral T cell response is believed to play a central role in the pathogenesis of hepatitis C virus infection. Since chronic evolution occurs in > 50% of HCV infections, the sequential analysis of the T cell response from the early clinical stages of disease may contribute to define the features of the T cell response associated with recovery or chronic viral persistence. For this purpose, 21 subjects with acute hepatitis C virus infection were sequentially followed for an average time of 44 wk. Twelve patients normalized transaminase values that remained normal throughout the follow-up period; all but two cleared hepatitis C virus-RNA from serum. The remaining nine patients showed persistent viremia and elevated transaminases. Analysis of the peripheral blood T cell proliferative response to core, E1, E2, NS3, NS4, and NS5 recombinant antigens and synthetic peptides showed that responses to all hepatitis C virus antigens, except E1, were significantly more vigorous and more frequently detectable in patients who normalized transaminase levels than in those who did not. By sequential evaluation of the T cell response, a difference between the two groups of patients was already detectable at the very early stages of acute infection and then maintained throughout the follow-up period. The results suggest that the vigor of the T cell response during the early stages of infection may be a critical determinant of disease resolution and control of infection.

Different neurotransmitter systems are involved in the development of esophageal achalasia

Clinical and pharmacological evidence suggests that several neurotransmitters are involved in the control of the esophageal motility; in fact, besides the well known cholinergic and sympathetic innervation, Vasoactive Intestinal Polypeptide (VIP)-containing fibers as well as dopamine (DA)-containing nerve endings have been identified within the esophageal wall. Lower Esophageal Sphincter (LES) achalasia is a neuromuscular disorder characterized by the absence of peristalsis in the body of the esophagus and by the failure of the LES to relax in response to swallowing. Stimulation of both VIP receptors and D-2 DA receptors induce a decrease in LES pressure, while D-1 receptors mediates LES contractions. In the present study we show that both VIP and DA system is disregulated in LES achalasia. In particular, this disease is associated not only with the lack of VIP nerves in the LES, but also with a failure in the responsiveness of postsynaptic receptors to VIP stimulation. Furthermore, we demonstrate a selective functional loss of the D-2 DA receptor component, without changes in the D-1 DA receptor mediated responses.

Infection of circulating and liver infiltrating T cells by hepatitis C virus of different subtypes

Hepatitis C virus (HCV) infection display a very high rate of progression to chronicity and, like many other viruses causing persistent infections, it displays a tropism for the cells of the immune system. Peripheral blood mononuclear cells (PBMCs) from 21 HCV chronic carriers and long-term T cell clones derived from circulating or liver infiltrating T lymphocytes were tested by cDNA "nested" PCR for positive and negative strand HCV-RNA. The presence of HCV genomes in PBMCs is a frequent, although not constant, finding and can be accompanied by active viral replication, as suggested by the coexistence of negative strand HCV-RNA. Infected T cells are more represented in livers than in periphery, as indicated by comparing HCV-RNA detection in T cell clones isolated from both the compartments. Sequencing of viral genomes present in PBMCs and liver infiltrating lymphocytes showed that all the three major HCV genotypes present in our population of chronic carriers can infect lymphoid cells. Although each clonal population of T cells is infected by a single strain of HCV, in the same patient lymphoid cells can harbor different viral populations, different from those circulating at that moment in the serum.

[Cytokine mediators in acute inflammation and chronic course of viral hepatitis]

Cytokines constitute a complex network of molecules involved in the regulation of the inflammatory response and the homeostasis of organ functions. Cytokines coordinate physiologic and pathologic processes going on in the liver, such as liver growth and regeneration, inflammatory processes including viral liver disease, liver fibrosis and cirrhosis. Liver growth and regeneration are regulated by several cytokines. The platelet-derived hepatocyte growth factor, in particular, delivers a strong mitogenic stimulus for hepatocyte regeneration. The cell-mediated immune response plays a central role in hepatocellular necrosis and in the immunopathogenetic mechanisms involved in viral clearance and persistence in liver disease of viral etiology. In this context, cytokines modulate the immune system and exert direct antiviral activity by cytopathic and non-cytopathic mechanisms, as demonstrated in a transgenic mouse model. IL-6, TNF-alpha, IL-1 and IL-2 increase in acute fulminant viral hepatitis; in fact, they have pro-inflammatory and cytotoxic effects. Reduced IL-2 and IFN-alpha synthesis and increased serum levels of IL-1 and IL-2 soluble receptor (IL-2R) have been observed in HBV chronic liver disease. In HCV chronic hepatitis, IL-2R increases as well, while IFN-gamma and IL-2 decrease. In personal experimental observations, intra-hepatic messenger RNA expression of several cytokines was measured in liver specimens of patients with chronic HBV and HCV infections: patients with HCV chronic liver disease had higher levels of IL-2, IL-6, IL-10, and IFN-gamma. These data are in accordance with immunological studies showing a vigorous cell-mediated immune response in HCV chronic liver disease and a deficient immune response in HBV chronic hepatitis.(ABSTRACT TRUNCATED AT 250 WORDS)

Class I-restricted cytotoxic T lymphocytes are directly cytopathic for their target cells in vivo

Although CD8-positive, class I-restricted CTL play a critical role in viral clearance and immunopathology in many model systems, they have not been shown to directly kill their target cells in vivo at the single cell level. Using a hepatitis B surface Ag transgenic mouse model of class I-restricted, CTL-mediated liver disease, we now demonstrate that CD8-positive, Ld-restricted hepatitis B surface Ag-specific CTL bind and kill their target cells in vivo by triggering them to undergo degenerative cytologic changes compatible with apoptosis. Unexpectedly, the data also indicate that the pathologic consequences of this direct, Ag-specific CTL effect are much less severe than the cytodestructive, Ag-nonspecific inflammatory response that they induce when they are activated by Ag recognition.

Class I-restricted cytotoxic T lymphocytes are directly cytopathic for their target cells in vivo

Although CD8-positive, class I-restricted CTL play a critical role in viral clearance and immunopathology in many model systems, they have not been shown to directly kill their target cells in vivo at the single cell level. Using a hepatitis B surface Ag transgenic mouse model of class I-restricted, CTL-mediated liver disease, we now demonstrate that CD8-positive, Ld-restricted hepatitis B surface Ag-specific CTL bind and kill their target cells in vivo by triggering them to undergo degenerative cytologic changes compatible with apoptosis. Unexpectedly, the data also indicate that the pathologic consequences of this direct, Ag-specific CTL effect are much less severe than the cytodestructive, Ag-nonspecific inflammatory response that they induce when they are activated by Ag recognition.

T-cell response to structural and nonstructural hepatitis C virus antigens in persistent and self-limited hepatitis C virus infections

Twenty-nine patients with chronic hepatitis C and 15 asymptomatic hepatitis C virus antibody-positive subjects who clinically recovered from hepatitis C virus infection were studied for their peripheral blood lymphomononuclear cell proliferative response to hepatitis C virus structural and nonstructural antigens (core, envelope, nonstructural 4 and nonstructural 5) expressed in yeast as superoxide dismutase fusion proteins, in an initial attempt to define some of the features of the virus-specific immune response. Hepatitis C virus core was the most immunogenic antigen for human leukocyte antigen class II-restricted T cells in both groups of patients studied, and the proliferative response to it was the most vigorous and the most frequently expressed in comparison with the other antigens tested. The specificity of the results was supported by the lack of response to hepatitis C virus antigens by healthy uninfected controls and confirmed by recognition of recombinant core proteins of different origin (yeast and baculovirus) by polyclonal T-cell lines produced by T-cell stimulation with yeast-derived core. Each of the antigens tested was able to induce significant although variable levels of proliferative response, indicating that all can be immunogenic at the T-cell level. Significant proliferative responses to core, nonstructural 4 and nonstructural 5 antigens were more frequently detected in subjects who were able to eradicate infection than in patients with chronic hepatitis C, although the difference was statistically not significant. No difference was observed between the two groups of patients with respect to the response to the putative envelope antigens.

Opposing roles for D-1 and D-2 dopamine receptors in the regulation of lower esophageal sphincter motility in the rat

In the present study we have identified biochemically DA receptors in rat Lower Esophageal Sphincter (LES) and have identified their role in the control of the sphincter motility. Dopamine (DA) both stimulated and inhibited cyclic AMP formation in rat LES; the pharmacological characterization of these effects indicated that they were mediated by D-1 and D-2 receptors, respectively. The results obtained with LES helical strips showed that DA plays both inhibitory and stimulatory effects on the sphincter function; the pharmacological characterization with selective D-1 and D-2 agonists and antagonists strongly suggested that D-1 receptors are involved in LES contraction, while D-2 receptors mediate the relaxation of the sphincter. The same results were obtained by measuring intraluminal LES pressure in anesthetized rats. The selective D-1 agonist fenoldopam (40 micrograms/kg, i.v.) increased the LES pressure; on the other hand bromocriptine (10 micrograms/kg, i.v.), which preferentially interacts with D-2 receptors, induced a decrease of the resting LES pressure.

Human leukocyte antigen class I-independent pathways may contribute to hepatitis B virus-induced liver disease after liver transplantation

The proliferative response of peripheral blood lymphocytes to the HBcAg was compared with serological, molecular and immunohistochemical parameters of hepatitis B virus infection and with biochemical and histological parameters of liver disease in a patient who received a completely human leukocyte antigen class I-mismatched liver allograft for fulminant hepatitis. The proliferative response increased progressively after transplantation, as hepatitis B virus infection became reestablished in the hepatic allograft. Strikingly, the HBcAg-specific T cells suddenly disappeared from the peripheral blood immediately before the acute onset of a severe necroinflammatory liver disease in which more than 80% of the hepatocytes expressed HBcAg. These observations are compatible with the hypothesis that human leukocyte antigen class I-independent hepatitis B virus-specific T cells might play a previously unsuspected role in the pathogenesis of hepatitis B virus-induced liver disease.

HLA A2 restricted cytotoxic T lymphocyte responses to multiple hepatitis B surface antigen epitopes during hepatitis B virus infection

Inasmuch as the hepatitis B virus (HBV) is not directly cytopathic for the infected hepatocyte, it is generally presumed that viral clearance and liver cell injury during viral hepatitis are due to a CTL response to HBV encoded Ag presented by HLA class I molecules. We have previously examined the peripheral blood CTL response to two HBV nucleocapsid epitopes in patients with acute and chronic viral hepatitis, one of which is restricted by HLA-A2, whereas the other is dually restricted by HLA-A31 and Aw68. In this study, we defined the HLA-A2-restricted CTL response to the hepatitis B surface Ag (HBsAg) by using a panel of HBsAg-derived synthetic peptides containing the ideal HLA-A2.1 binding motif (-L------V). Several novel aspects of HBV immunobiology and pathogenesis are evident from this study. First, the peripheral blood CTL response to HBV-encoded Ag is remarkably polyclonal and multispecific in most patients with acute hepatitis. Indeed, HLA-A2-restricted CTL specific for as many as four envelope epitopes and one nucleocapsid epitope were found to be present simultaneously in individual patients with acute viral hepatitis. Second, HBV-specific CTL are not detectable in the peripheral blood in a minority of patients with acute hepatitis, nor have we detected a CTL response in any of the patients with chronic hepatitis that we have studied thus far. Although the cellular and molecular basis for CTL nonresponse remains to be determined, the data suggest that it may contribute to viral persistence. Third, the diversity and the specificity of the CTL response is determined in part by the coding sequence of the viral genome present in each infected patient. Indeed, the apparent nonresponse of some acutely infected patients to at least one HBsAg-specific CTL epitope actually reflects infection by a viral variant that contains a critical substitution in one of the anchor residues within the epitope. Finally, at a fundamental level, the data suggest that the presence of the HLA-A2.1-binding motif in a peptide may not be sufficient for binding; and the capacity of a peptide to bind the class I molecule does not guarantee that it will be immunogenic.

HLA A2 restricted cytotoxic T lymphocyte responses to multiple hepatitis B surface antigen epitopes during hepatitis B virus infection

Inasmuch as the hepatitis B virus (HBV) is not directly cytopathic for the infected hepatocyte, it is generally presumed that viral clearance and liver cell injury during viral hepatitis are due to a CTL response to HBV encoded Ag presented by HLA class I molecules. We have previously examined the peripheral blood CTL response to two HBV nucleocapsid epitopes in patients with acute and chronic viral hepatitis, one of which is restricted by HLA-A2, whereas the other is dually restricted by HLA-A31 and Aw68. In this study, we defined the HLA-A2-restricted CTL response to the hepatitis B surface Ag (HBsAg) by using a panel of HBsAg-derived synthetic peptides containing the ideal HLA-A2.1 binding motif (-L------V). Several novel aspects of HBV immunobiology and pathogenesis are evident from this study. First, the peripheral blood CTL response to HBV-encoded Ag is remarkably polyclonal and multispecific in most patients with acute hepatitis. Indeed, HLA-A2-restricted CTL specific for as many as four envelope epitopes and one nucleocapsid epitope were found to be present simultaneously in individual patients with acute viral hepatitis. Second, HBV-specific CTL are not detectable in the peripheral blood in a minority of patients with acute hepatitis, nor have we detected a CTL response in any of the patients with chronic hepatitis that we have studied thus far. Although the cellular and molecular basis for CTL nonresponse remains to be determined, the data suggest that it may contribute to viral persistence. Third, the diversity and the specificity of the CTL response is determined in part by the coding sequence of the viral genome present in each infected patient. Indeed, the apparent nonresponse of some acutely infected patients to at least one HBsAg-specific CTL epitope actually reflects infection by a viral variant that contains a critical substitution in one of the anchor residues within the epitope. Finally, at a fundamental level, the data suggest that the presence of the HLA-A2.1-binding motif in a peptide may not be sufficient for binding; and the capacity of a peptide to bind the class I molecule does not guarantee that it will be immunogenic.

Definition of a minimal optimal cytotoxic T-cell epitope within the hepatitis B virus nucleocapsid protein

Residues 11 to 27 of the hepatitis B virus nucleocapsid antigen contain a cytotoxic T-cell epitope that is recognized by cytotoxic T cells from virtually all HLA-A2-positive patients with acute hepatitis B virus infection. Using panels of truncated and overlapping peptides, we now show that the optimal amino acid sequence recognized by cytotoxic T cells is a 10-mer (residues 18 to 27) containing the predicted peptide-binding motif for HLA-A2 and that this peptide can stimulate cytotoxic T cells able to recognize endogenously synthesized hepatitis B core antigen. Since patients with chronic hepatitis B virus infection fail to mount an efficient cytotoxic T-cell response to it, this epitope might serve as the starting point for the design of synthetic peptide-based immunotherapeutic strategies to terminate persistent viral infection.

HLA-A31- and HLA-Aw68-restricted cytotoxic T cell responses to a single hepatitis B virus nucleocapsid epitope during acute viral hepatitis

We have recently developed the technology to identify and characterize the human histocompatibility leukocyte antigen (HLA) class I-restricted, CD8+ cytotoxic T lymphocyte (CTL) response to hepatitis B virus (HBV)-encoded antigens in patients with acute viral hepatitis. CTL are expanded in vitro by stimulation with HBV-derived synthetic peptides and selected by restimulation with a panel of HLA-matched stable transfectants that express the corresponding HBV protein. We have recently reported the existence of an HLA-A2-restricted, CD8+ CTL response to an epitope located between residues 18 and 27 of the HBV nucleocapsid core antigen (HBcAg). We now report the discovery of a CTL epitope located between HBcAg residues 141 and 151 that completely overlaps a critical domain in the viral nucleocapsid protein that is essential for its nuclear localization and genome packaging functions as well as processing of the precore protein. The CTL response to this epitope is dually restricted by the HLA-A31 and HLA-Aw68 alleles, which, unexpectedly, appear to use a common binding motif based on the results of alanine substitution and competition analysis, and the binding properties of these two alleles predicted from their known primary sequence, and from the three-dimensional structure of HLA-Aw68. We have also demonstrated that the HBV-specific CTL response to this epitope is polyclonal during acute viral hepatitis, since these two restriction elements can present the HBcAg 141-151 epitope to independent CTL clones derived from a single patient; and that the CTL response is multispecific, since HLA-A2-restricted and HLA-Aw68-restricted CTL responses to HBcAg 18-27 and HBcAg 141-151, respectively, have been identified to coexist in another patient. The foregoing argue against the emergence of CTL escape mutants as a significant problem during HBV infection, especially at this locus, where mutations might be incompatible with viral replication. Finally, our data suggest an association between the HBV-specific CTL response and viral clearance, and they have implications for the design of immunotherapeutic strategies to terminate HBV infection in chronically infected patients.