Predicting de-novo portal vein thrombosis after HCV eradication: A long-term competing risk analysis in the ongoing PITER cohort.

BACKGROUND & AIMS: Sustained virological response (SVR) by direct-acting antivirals (DAAs) may reverse the hypercoagulable state of HCV cirrhosis and the portal vein thrombosis (PVT) risk. We evaluated the incidence and predictive factors of de novo, non-tumoral PVT in patients with cirrhosis after HCV eradication. METHODS: Patients with HCV-related cirrhosis, consecutively enrolled in the multi-center ongoing PITER cohort, who achieved the SVR using DAAs, were prospectively evaluated. Kaplan-Meier and competing risk regression analyses were performed. RESULTS: During a median time of 38.3 months (IQR: 25.1-48.7 months) after the end of treatment (EOT), among 1609 SVR patients, 32 (2.0%) developed de novo PVT. A platelet count ≤120,000/µL, albumin levels ≤3.5 mg/dL, bilirubin >1.1 mg/dL, a previous liver decompensation, ALBI, Baveno, FIB-4, and RESIST scores were significantly different (p < 0.001), among patients who developed PVT versus those who did not. Considering death and liver transplantation as competing risk events, esophageal varices (subHR: 10.40; CI 95% 4.33-24.99) and pre-treatment ALBI grade ≥2 (subHR: 4.32; CI 95% 1.36-13.74) were independent predictors of PVT. After HCV eradication, a significant variation in PLT count, albumin, and bilirubin (p < 0.001) versus pre-treatment values was observed in patients who did not develop PVT, whereas no significant differences were observed in those who developed PVT (p > 0.05). After the EOT, esophageal varices and ALBI grade ≥2, remained associated with de novo PVT (subHR: 9.32; CI 95% 3.16-27.53 and subHR: 5.50; CI 95% 1.67-18.13, respectively). CONCLUSIONS: In patients with HCV-related cirrhosis, a more advanced liver disease and significant portal hypertension are independently associated with the de novo PVT risk after SVR.

Profiling the risk of hepatocellular carcinoma after long-term HCV eradication in patients with liver cirrhosis in the PITER cohort.

BACKGROUND AND AIMS: Severe liver disease markers assessed before HCV eradication are acknowledged to usually improve after the SVR. We prospectively evaluated, in the PITER cohort, the long-term HCC risk profile based on predictors monitored after HCV eradication by direct-acting antivirals in patients with cirrhosis. METHODS: HCC occurrence was evaluated by Kaplan-Meier analysis. Cox regression analysis identified the post-treatment variables associated with de-novo HCC; their predictive power was presented in a nomogram. RESULTS: After the end of therapy (median follow-up:28.47 months), among 2064 SVR patients, 119 (5.8%) developed de-novo HCC. The HCC incidence was 1.90%, 4.21%, 6.47% at 12-, 24- and 36-months from end-of-therapy, respectively (incidence rate 2.45/100 person-years). Age, genotype 3, diabetes, platelets (PLT)≤120,000/µl and albumin ≤3.5g/dl levels were identified as pre-treatment HCC independent predictors. Adjusting for age, the post-treatment PLT≤120,000/µl (AdjHR 1.92; 95%CI:1.06-3.45) and albumin≤3.5g/dl (AdjHR 4.38; 95%CI 2.48-7.75) values were independently associated with HCC occurrence. Two different risk profiles were identified by combining long-term post-therapy evaluation of PLT ≤ vs. >120,000/µl and albumin ≤ vs. >3.5g/dl showing a significant different HCC incidence rate of 1.35 vs. 3.77/100 p-y, respectively. CONCLUSIONS: The nomogram score based on age, PLT and albumin levels after SVR showed an accurate prediction capability and may support the customizing management for early HCC detection.

Trends in chronic hepatitis B virus infection in Italy over a 10-year period: Clues from the nationwide PITER and MASTER cohorts toward elimination.

OBJECTIVES: The study measures trends in the profile of patients with chronic hepatitis B virus linked to care in Italy. METHODS: A cross-sectional, multicenter, observational cohort (PITER cohort) of consecutive patients with hepatitis B surface antigen (HBsAg) over the period 2019-2021 from 46 centers was evaluated. The reference was the MASTER cohort collected over the years 2012-2015. Standard statistical methods were used. RESULTS: The PITER cohort enrolled 4583 patients, of whom 21.8% were non-Italian natives. Compared with those in MASTER, the patients were older and more often female. The prevalence of hepatitis B e antigen (HBeAg) declined (7.2% vs 12.3; P <0.0001) and that of anti-hepatitis D virus (HDV) remained stable (9.3% vs 8.3%). In both cohorts, about 25% of the patients had cirrhosis, and those in the PITER cohort were older. HBeAg-positive was 5.0% vs 12.6% (P <0.0001) and anti-HDV positive 24.8% vs 17.5% (P <0.0017). In the logistic model, the variables associated with cirrhosis were anti-HDV-positive (odds ratio = 10.08; confidence interval 7.63-13.43), age, sex, and body mass index; the likelihood of cirrhosis was reduced by 40% in the PITER cohort. Among non-Italians, 12.3% were HBeAg-positive (vs 23.4% in the MASTER cohort; P <0.0001), and 12.3% were anti-HDV-positive (vs 11.1%). Overall, the adherence to the European Association for the Study of the Liver recommendations for antiviral treatment increased over time. CONCLUSION: Chronic hepatitis B virus infection appears to be in the process of becoming under control in Italy; however, HDV infection is still a health concern in patients with cirrhosis and in migrants.

Obesity and Dysmetabolic Factors among Deceased COVID-19 Adults under 65 Years of Age in Italy: A Retrospective Case-Control Study.

BACKGROUND: Italy has witnessed high levels of COVID-19 deaths, mainly at the elderly age. We assessed the comorbidity and the biochemical profiles of consecutive patients ≤65 years of age to identify a potential risk profile for death. METHODS: We retrospectively analyzed clinical data from consecutive hospitalized-for-COVID-19 patients ≤65 years, who were died (593 patients) or discharged (912 patients) during February-December 2020. Multivariate logistic regression identified the mortality risk factors. RESULTS: Overweight (adjusted odds ratio (adjOR) 5.53, 95% CI 2.07-14.76), obesity (adjOR 8.58, CI 3.30-22.29), dyslipidemia (adjOR 10.02, 95% CI 1.06-94.22), heart disease (adjOR 17.68, 95% CI 3.80-82.18), cancer (adjOR 13.28, 95% CI 4.25-41.51) and male sex (adjOR 5.24, 95% CI 2.30-11.94) were associated with death risk in the youngest population. In the older population (46-65 years of age), the overweight and obesity were also associated with the death risk, however at a lower extent: the adjORs varyied from 1.49 to 2.36 for overweight patients and from 3.00 to 4.07 for obese patients. Diabetes was independently associated with death only in these older patients. CONCLUSION: Overweight, obesity and dyslipidemia had a pivotal role in increasing young individuals' death risk. Their presence should be carefully evaluated for prevention and/or prompt management of SARS-CoV2 infection in such high-risk patients to avoid the worst outcomes.

A prospective study of direct-acting antiviral effectiveness and relapse risk in HCV cryoglobulinemic vasculitis by the Italian PITER cohort.

BACKGROUND AND AIMS: Mixed cryoglobulinemia is the most common HCV extrahepatic manifestation. We aimed to prospectively evaluate the cryoglobulinemic vasculitis (CV) clinical profile after a sustained virologic response (SVR) over a medium-term to long-term period. APPROACH AND RESULTS: Direct-acting antiviral-treated cryoglobulinemic patients, consecutively enrolled in the multicentric Italian Platform for the Study of Viral Hepatitis Therapy cohort, were prospectively evaluated. Cumulative incidence Kaplan-Meier curves were reported for response, clinical deterioration, relapse and relapse-free survival rates. Cox regression analysis evaluated factors associated with different outcomes. A clinical response was reported in at least one follow-up point for 373 of 423 (88%) patients with CV who achieved SVR. Clinical response increased over time with a 76% improvement rate at month 12 after the end of treatment. A full complete response (FCR) was reached by 164 (38.8%) patients in at least one follow-up point. CV clinical response fluctuated, with some deterioration of the initial response in 49.6% of patients (median time of deterioration, 19 months). In patients who achieved FCR and had an available follow-up (137 patients) a relapse was observed in 13% and it was transient in 66.7% of patients. The rate of patients without any deterioration was 58% and 41% at 12 and 24 months, respectively. After achieving SVR, a clinical nonresponse was associated with older age and renal involvement; a clinical deterioration/relapse was associated with high pretreatment rheumatoid factor values, and FCR was inversely associated with age, neuropathy, and high cryocrit levels. CONCLUSION: In patients with CV, HCV eradication may not correspond to a persistent clinical improvement, and clinical response may fluctuate. This implies an attentive approach to post-SVR evaluation through prognostic factors and tailored treatment.

Liver function following hepatitis C virus eradication by direct acting antivirals in patients with liver cirrhosis: data from the PITER cohort.

BACKGROUND: The development of direct-acting antivirals (DAA) for HCV has revolutionized the treatment of HCV, including its treatment in patients with HIV coinfection. The aim of this study was to compare the changes in liver function between coinfected and monoinfected patients with cirrhosis who achieved HCV eradication by DAA. METHODS: Patients with pre-treatment diagnosis of HCV liver cirrhosis, consecutively enrolled in the multicenter PITER cohort, who achieved a sustained virological response 12 weeks after treatment cessation (SVR12) were analysed. Changes in Child-Pugh (C-P) class and the occurrence of a decompensating event was prospectively evaluated after the end of DAA treatment. Cox regression analysis was used to evaluate factors independently associated with changes in liver function following viral eradication. RESULTS: We evaluated 1350 patients, of whom 1242 HCV monoinfected (median follow-up 24.7, range 6.8-47.5 months after viral eradication) and 108 (8%) HCV/HIV coinfected (median follow-up 27.1, range 6.0-44.6). After adjusting for age, sex, HCV-genotype, HBsAg positivity and alcohol use, HIV was independently associated with a more advanced liver disease before treatment (C-P class B/C vs A) (OR: 3.73, 95% CI:2.00-6.98). Following HCV eradication, C-P class improved in 17/20 (85%) coinfected patients (from B to A and from C to B) and in 53/82 (64.6%) monoinfected patients (from B to A) (p = 0.08). C-P class worsened in 3/56 coinfected (5.3%) (from A to B) and in 84/1024 (8.2%) monoinfected patients (p = 0.45) (from A to B or C and from B to C). Baseline factors independently associated with C-P class worsening were male sex (HR = 2.00; 95% CI = 1.18-3.36), platelet count < 100,000/µl (HR = 1.75; 95% CI 1.08-2.85) and increased INR (HR = 2.41; 95% CI 1.51-3.84). Following viral eradication, in 7 of 15 coinfected (46.6%) and in 61 of 133 (45.8%) monoinfected patients with previous history of decompensation, a new decompensating event occurred. A first decompensating event was recorded in 4 of 93 (4.3%) coinfected and in 53 of 1109 (4.8%) monoinfected patients (p = 0.83). CONCLUSIONS: Improvement of liver function was observed following HCV eradication in the majority of patients with cirrhosis; however viral eradication did not always mean cure of liver disease in both monoinfected and coinfected patients with advanced liver disease.

Clinical features and comorbidity pattern of HCV infected migrants compared to native patients in care in Italy: A real-life evaluation of the PITER cohort.

BACKGROUND: Direct-acting antivirals are highly effective for the treatment of hepatitis C virus (HCV) infection, regardless race/ethnicity. We aimed to evaluate demographic, virological and clinical data of HCV-infected migrants vs. natives consecutively enrolled in the PITER cohort. METHODS: Migrants were defined by country of birth and nationality that was different from Italy. Mann-Whitney U test, Chi-squared test and multiple logistic regression were used. RESULTS: Of 10,669 enrolled patients, 301 (2.8%) were migrants: median age 47 vs. 62 years, (p < 0.001), females 56.5% vs. 45.3%, (p < 0.001), HBsAg positivity 3.8% vs. 1.4%, (p < 0.05). Genotype 1b was prevalent in both groups, whereas genotype 4 was more prevalent in migrants (p < 0.05). Liver disease severity and sustained virologic response (SVR) were similar. A higher prevalence of comorbidities was reported for natives compared to migrants (p < 0.05). Liver disease progression cofactors (HBsAg, HIV coinfection, alcohol abuse, potential metabolic syndrome) were present in 39.1% and 47.1% (p > 0.05) of migrants and natives who eradicated HCV, respectively. CONCLUSION: Compared to natives, HCV-infected migrants in care have different demographics, HCV genotypes, viral coinfections and comorbidities and similar disease severity, SVR and cofactors for disease progression after HCV eradication. A periodic clinical assessment after HCV eradication in Italians and migrants with cofactors for disease progression is warranted.

Advanced liver disease outcomes after hepatitis C eradication by human immunodeficiency virus infection in PITER cohort.

BACKGROUND: Liver disease progression after Hepatitis C Virus (HCV) eradication following direct-acting antiviral (DAA) treatment in the real-life setting according to Human Immunodeficiency Virus (HIV) coinfection was evaluated. METHODS: Patients consecutively enrolled in PITER between April 2014 and June 2019 and with at least 12-weeks follow-up following treatment were analysed. Cox regression analysis were used to evaluate HIV coinfection and factors independently associated with liver disease outcomes following viral eradication in DAA treated patients with pre-treatment liver cirrhosis. RESULTS: 93 HIV/HCV coinfected and 1109 HCV monoinfected patients were evaluated during a median follow-up of 26.7 (range 6-44.6) and 24.6 (range 6.8-47.3) months, respectively. No difference in the cumulative HCC incidence and hepatic decompensation was observed between coinfected and monoinfected patients. Age (Hazard Ratio [HR] = 1.08; 95% CI 1.04-1.13), male sex (HR = 2.76; 95% CI 1.28-5.96), lower albumin levels (HR = 3.94; 95% CI 1.81-8.58), genotype 3 (HR = 5.05; 95% CI 1.75-14.57) and serum anti-HBc positivity (HR = 1.99, 95% CI 1.01-3.95) were independently associated with HCC incidence. Older age (HR = 1.03; 95% CI 1.00-1.07), male sex (HR = 2.13; 95% CI 1.06-4.26) and lower albumin levels (HR = 3.75; 95% CI 1.89-7.46) were independently associated with the appearance of a decompensating event after viral eradication. CONCLUSION: Different demographic, clinical and genotype distribution between HIV coinfected vs those monoinfected, was observed in a representative cohort of HCV infected patients in Italy. Once liver cirrhosis is established the disease progression is decreased, but still persists regardless of viral eradication in both coinfected and monoinfected patients. In patients with cirrhosis, HIV coinfection was not associated with a higher probability of liver complications, after viral eradication.

Real-life use of elbasvir/grazoprevir in adults and elderly patients: a prospective evaluation of comedications used in the PITER cohort.

BACKGROUND: In patients treated for HCV infection, potential drug-drug interactions (DDIs) can occur among direct-acting antiviral drugs (DAAs) and comedications used. The real-life effectiveness and safety of elbasvir/grazoprevir (ELB/GZR) among co-medicated HCV patients was evaluated. METHODS: We prospectively evaluated consecutive patients from 15 clinical centres participating in PITER who were treated with ELB/GZR and had been followed for at least 12 weeks after treatment. Data were prospectively collected on the use of comedications (including discontinuation, dose modification and addition of drugs) and potential DDIs with DAAs. RESULTS: Of the 356 patients with at least 12-week post-treatment follow-up (median age 67, range 50-88 years), 338 (95%) achieved sustained virological response. Of these, 219 (60%) had at least one comorbidity (median 2, range 1-6); information on comedication was available for 212 of them. Of 190 comedications used, 15 (8%) drugs were modified during ELB/GZR therapy, specifically in 9 (4%) patients they were interrupted, in 2 (1%) of whom, the comedication was interrupted before the DAA therapy because of potential DDI (that is, patients treated with carbamazepine); in 12 (6%) patients the comedications were modified in terms of dosage. In 29 (14%) patients, the comedications required monitoring when used with ELB/GZR, as well as with all available DAAs. Of the 190 drugs, 27 (14%) used in 67% of patients were free of DDIs when used with ELB/GZR, whereas they required monitoring if used with other DAA regimens. CONCLUSIONS: The results of this prospective study support findings that ELB/GZR is effective and safe in most treated patients.

Correction: Real-life data on potential drug-drug interactions in patients with chronic hepatitis C viral infection undergoing antiviral therapy with interferon-free DAAs in the PITER Cohort Study.

[This corrects the article DOI: 10.1371/journal.pone.0172159.].

Incidence of DAA failure and the clinical impact of retreatment in real-life patients treated in the advanced stage of liver disease: Interim evaluations from the PITER network.

BACKGROUND: Few data are available on the virological and clinical outcomes of advanced liver disease patients retreated after first-line DAA failure. AIM: To evaluate DAA failure incidence and the retreatment clinical impact in patients treated in the advanced liver disease stage. METHODS: Data on HCV genotype, liver disease severity, and first and second line DAA regimens were prospectively collected in consecutive patients who reached the 12-week post-treatment and retreatment evaluations from January 2015 to December 2016 in 23 of the PITER network centers. RESULTS: Among 3,830 patients with advanced fibrosis (F3) or cirrhosis, 139 (3.6%) failed to achieve SVR. Genotype 3, bilirubin levels >1.5mg/dl, platelet count <120,000/mm3 and the sofosbuvir+ribavirin regimen were independent predictors of failure by logistic regression analysis. The failure rate was 7.6% for patients treated with regimens that are no longer recommended or considered suboptimal (sofosbuvir+ribavirin or simeprevir+sofosbuvir±ribavirin), whereas 1.4% for regimens containing sofosbuvir combined with daclatasvir or ledipasvir or other DAAs. Of the patients who failed to achieve SVR, 72 (51.8%) were retreated with a second DAA regimen, specifically 38 (52.7%) with sofosbuvir+daclatasvir, 27 (37.5%) with sofosbuvir+ledipasvir, and 7 (9.7%) with other DAAs ±ribavirin. Among these, 69 (96%) patients achieved SVR12 and 3 (4%) failed. During a median time of 6 months (range: 5-14 months) between failure and the second DAA therapy, the Child-Pugh class worsened in 12 (16.7%) patients: from A to B in 10 patients (19.6%) and from B to C in 2 patients (10.5%), whereas it did not change in the remaining 60 patients. Following the retreatment SVR12 (median time of 6 months; range: 3-12 months), the Child-Pugh class improved in 17 (23.6%) patients: from B to A in 14 (19.4%) patients, from C to A in 1 patient (1.4%) and from C to B in 2 (2.9%) patients; it remained unchanged in 53 patients (73.6%) and worsened in 2 (2.8%) patients. Of patients who were retreated, 3 (4%) had undergone OLT before retreatment (all reached SVR12 following retreatment) and 2 (2.8%) underwent OLT after having achieved retreatment SVR12. Two (70%) of the 3 patients who failed to achieve SVR12 after retreatment, and 2 (2.8%) of the 69 patients who achieved retreatment SVR12 died from liver failure (Child-Pugh class deteriorated from B to C) or HCC complications. CONCLUSIONS: Failure rate following the first DAA regimen in patients with advanced disease is similar to or lower than that reported in clinical trials, although the majority of patients were treated with suboptimal regimens. Interim findings showed that worsening of liver function after failure, in terms of Child Pugh class deterioration, was improved by successful retreatment in about one third of retreated patients within a short follow-up period; however, in some advanced liver disease patients, clinical outcomes (Child Pugh class, HCC development, liver failure and death) were independent of viral eradication.

Modeling cost-effectiveness and health gains of a "universal" versus "prioritized" hepatitis C virus treatment policy in a real-life cohort.

We evaluated the cost-effectiveness of two alternative direct-acting antiviral (DAA) treatment policies in a real-life cohort of hepatitis C virus-infected patients: policy 1, "universal," treat all patients, regardless of fibrosis stage; policy 2, treat only "prioritized" patients, delay treatment of the remaining patients until reaching stage F3. A liver disease progression Markov model, which used a lifetime horizon and health care system perspective, was applied to the PITER cohort (representative of Italian hepatitis C virus-infected patients in care). Specifically, 8,125 patients naive to DAA treatment, without clinical, sociodemographic, or insurance restrictions, were used to evaluate the policies' cost-effectiveness. The patients' age and fibrosis stage, assumed DAA treatment cost of €15,000/patient, and the Italian liver disease costs were used to evaluate quality-adjusted life-years (QALY) and incremental cost-effectiveness ratios (ICER) of policy 1 versus policy 2. To generalize the results, a European scenario analysis was performed, resampling the study population, using the mean European country-specific health states costs and mean treatment cost of €30,000. For the Italian base-case analysis, the cost-effective ICER obtained using policy 1 was €8,775/QALY. ICERs remained cost-effective in 94%-97% of the 10,000 probabilistic simulations. For the European treatment scenario the ICER obtained using policy 1 was €19,541.75/QALY. ICER was sensitive to variations in DAA costs, in the utility value of patients in fibrosis stages F0-F3 post-sustained virological response, and in the transition probabilities from F0 to F3. The ICERs decrease with decreasing DAA prices, becoming cost-saving for the base price (€15,000) discounts of at least 75% applied in patients with F0-F2 fibrosis. CONCLUSION: Extending hepatitis C virus treatment to patients in any fibrosis stage improves health outcomes and is cost-effective; cost-effectiveness significantly increases when lowering treatment prices in early fibrosis stages. (Hepatology 2017;66:1814-1825).

Real-life data on potential drug-drug interactions in patients with chronic hepatitis C viral infection undergoing antiviral therapy with interferon-free DAAs in the PITER Cohort Study.

BACKGROUND: There are few real-life data on the potential drug-drug interactions (DDIs) between anti-HCV direct-acting antivirals (DAAs) and the comedications used. AIM: To assess the potential DDIs of DAAs in HCV-infected outpatients, according to the severity of liver disease and comedication used in a prospective multicentric study. METHODS: Data from patients in 15 clinical centers who had started a DAA regimen and were receiving comedications during March 2015 to March 2016 were prospectively evaluated. The DDIs for each regimen and comedication were assigned according to HepC Drug Interactions (www.hep-druginteractions.org). RESULTS: Of the 449 patients evaluated, 86 had mild liver disease and 363 had moderate-to-severe disease. The use of a single comedication was more frequent among patients with mild liver disease (p = 0.03), whereas utilization of more than three drugs among those with moderate-to-severe disease (p = 0.05). Of the 142 comedications used in 86 patients with mild disease, 27 (20%) may require dose adjustment/closer monitoring, none was contraindicated. Of the 322 comedications used in 363 patients with moderate-to-severe liver disease, 82 (25%) were classified with potential DDIs that required only monitoring and dose adjustments; 10 (3%) were contraindicated in severe liver disease. In patients with mild liver disease 30% (26/86) used at least one drug with a potential DDI whereas of the 363 patients with moderate-to-severe liver disease, 161 (44%) were at risk for one or more DDI. CONCLUSIONS: Based on these results, we can estimate that 30-44% of patients undergoing DAA and taking comedications are at risk of a clinically significant DDI. This data indicates the need for increased awareness of potential DDI during DAA therapy, especially in patients with moderate-to-severe liver disease. For several drugs, the recommendation related to the DDI changes from "dose adjustment/closer monitoring", in mild to moderate liver disease, to "the use is contraindicated" in severe liver disease.

Glances in Immunology of HIV and HCV Infection.

Since the identification of HIV and HCV much progress has been made in the understanding of their life cycle and interaction with the host immune system. Despite these viruses markedly differ in their virological properties and in their pathogenesis, they share many common features in their immune escape and survival strategy. Both viruses have developed sophisticated ways to subvert and antagonize host innate and adaptive immune responses. In the last years, much effort has been done in the study of the AIDS pathogenesis and in the development of efficient treatment strategies, and a fatal infection has been transformed in a potentially chronic pathology. Much of this knowledge is now being transferred in the HCV research field, especially in the development of new drugs, although a big difference still remains between the outcome of the two infections, being HCV eradicable after treatment, whereas HIV eradication remains at present unachievable due to the establishment of reservoirs. In this review, we present current knowledge on innate and adaptive immune recognition and activation during HIV and HCV mono-infections and evasion strategies. We also discuss the genetic associations between components of the immune system, the course of infection, and the outcome of the therapies.

Exogenous HIV-1 Nef upsets the IFN-γ-induced impairment of human intestinal epithelial integrity.

BACKGROUND: The mucosal tissues play a central role in the transmission of HIV-1 infection as well as in the pathogenesis of AIDS. Despite several clinical studies reported intestinal dysfunction during HIV infection, the mechanisms underlying HIV-induced impairments of mucosal epithelial barrier are still unclear. It has been postulated that HIV-1 alters enterocytic function and HIV-1 proteins have been detected in several cell types of the intestinal mucosa. In the present study, we analyzed the effect of the accessory HIV-1 Nef protein on human epithelial cell line. METHODOLOGY/PRINCIPAL FINDINGS: We used unstimulated or IFN-γ-stimulated Caco-2 cells, as a model for homeostatic and inflamed gastrointestinal tracts, respectively. We investigated the effect of exogenous recombinant Nef on monolayer integrity analyzing its uptake, transepithelial electrical resistance, permeability to FITC-dextran and the expression of tight junction proteins. Moreover, we measured the induction of proinflammatory mediators. Exogenous Nef was taken up by Caco-2 cells, increased intestinal epithelial permeability and upset the IFN-γ-induced reduction of transepithelial resistance, interfering with tight junction protein expression. Moreover, Nef inhibited IFN-γ-induced apoptosis and up-regulated TNF-α, IL-6 and MIP-3α production by Caco-2 cells while down-regulated IL-10 production. The simultaneous exposure of Caco-2 cells to Nef and IFN-γ did not affect cytokine secretion respect to untreated cells. Finally, we found that Nef counteracted the IFN-γ induced arachidonic acid cascade. CONCLUSION/SIGNIFICANCE: Our findings suggest that exogenous Nef, perturbing the IFN-γ-induced impairment of intestinal epithelial cells, could prolong cell survival, thus allowing for accumulation of viral particles. Our results may improve the understanding of AIDS pathogenesis, supporting the discovery of new therapeutic interventions.

Effects of HIV-1 Nef on virus co-receptor expression and cytokine release in human bladder, laryngeal, and intestinal epithelial cell lines.

HIV infections are mainly acquired by mucosal transmission, through oral, rectal, or genital mucosa. Epithelial cells (EC) are the first cells encountered by HIV during infection through sexual transmission and breastfeeding. EC express several receptors critical for both primary HIV infection and secondary transmission. The regulation of co-receptor expression correlates with changes in susceptibility to infection by HIV-1 strains with different tropism. Moreover, inflammatory responses at mucosal surfaces after HIV-1 transmission may influence disease outcome. In the present study, we analyzed the effect of the accessory HIV-1 Nef protein on mucosal EC, using unstimulated or IFN-γ-stimulated HEp-2, T24, and Caco2 cell lines as models for homeostatic or inflamed mucosal tracts. We found that Nef significantly upregulated the expression of CXCR4 on the Caco-2 cell surface and the expression of galactosylceramide on the T24 cell surface. In addition, Nef significantly upregulated IL-6 production by T24 and Caco-2 cells, and TNF-α release by all three cell lines analyzed. Notably, Nef abrogated the IFN-γ-induced modulation of co-receptor expression and cytokine secretion. Our findings suggest that Nef differently regulates co-receptor expression and cytokine secretion at the epithelial level, depending on the anatomical derivation of the cells and the inflammatory status.

Docosahexaenoic acid modulates in vitro the inflammation of celiac disease in intestinal epithelial cells via the inhibition of cPLA2.

BACKGROUND & AIMS: The cytosolic phospolypase A(2) (cPLA(2)) - dependent release of arachidonic acid (AA) from the intra-epithelial lymphocytes plays a pivotal role in arming lymphocytes to cytolysis in the immune response of celiac disease. However, little is known about the role of enterocytes in releasing AA. Docosahexaenoic acid (DHA) is a long chain polyunsaturated fatty acid that counteracts many of the proinflammatory effect of AA. The aims of the present work were to evaluate if: 1) intestinal epithelial cells have a role in the celiac inflammation, releasing AA, and 2) if DHA is able to modulate the celiac inflammation, down-regulating the release of AA. METHODS: A human intestinal epithelial cell line (Caco-2) was exposed to gliadin peptides (PT-gl) (500 µg/ml) and DHA (2 µg/ml), both alone and simultaneously up to 24 h. RESULTS: The exposure of those cells to PT-gl alone resulted in an increased AA release, cycloxygenase-2 expression, cPLA(2) activity and prostaglandin E(2) and interleukin-8 release in culture medium, whereas the simultaneous exposure of the cells to DHA and PT-gl prevented the above-mentioned increases. CONCLUSIONS: These results suggest that intestinal epithelial cells sustain the celiac inflammation, releasing AA when stimulated with gliadin and that DHA inhibits the AA release by these cells.

Immunoregulatory effects of HIV-1 Nef protein.

During HIV infection, the perturbation of the adaptive and innate immune responses contributes to the progressive immunosuppression leading to an increased susceptibility to opportunistic infections and neoplastic diseases. Several impairments observed in HIV-infected patients include a gradual loss of CD4(+) T cells, CD8(+) T cell dysfunction, and a decreased number and function of natural killer (NK) cells. Moreover, a functional impairment and variation in the number of DC and B cells were observed during HIV infection. HIV-1 codes for proteins, including the accessory Nef proteins, that interacting with immune cells may contribute to AIDS pathogenesis. Here, we review the recent progress on the immunomodulatory effect of the accessory Nef protein and its role in the pathogenesis of HIV-1 infection. (c) 2009 International Union of Biochemistry and Molecular Biology, Inc.

Leptin exerts an anti-apoptotic effect on human dendritic cells via the PI3K-Akt signaling pathway.

Leptin is an adipocyte-derived hormone/cytokine that modulates immune responses. It induces functional and morphological changes in human dendritic cells (DCs), licensing them towards Th1 priming and promoting DC survival. Here we found that leptin protects DCs from spontaneous, UVB and H(2)O(2)-induced apoptosis, by triggering the activation of nuclear factor-kappa B (NF-kappaB) and a parallel up-regulation of bcl-2 and bcl-XL gene expression and Akt activation. We found that leptin activates the PI3K-Akt signaling pathway as demonstrated by the suppression of the effect of leptin on DC survival by wortmannin and API-2, which suppress the leptin-induced activation of Akt, NF-kappaB, bcl-2, bcl-XL and protection from apoptosis. These results provide insights on the immunoregulatory function of leptin, supporting a potential application in immunotherapeutic approaches.

Leptin as an immunological adjuvant: enhanced migratory and CD8+ T cell stimulatory capacity of human dendritic cells exposed to leptin.

Leptin is an adipocyte-derived hormone/cytokine that links nutrition, metabolism, and immune homeostasis and is endowed to modulate several immune responses. We previously demonstrated that both immature and mature human dendritic cells (DCs) express a functional leptin receptor, and we found that leptin activates DCs, licenses them for Th1 priming, and promotes DC survival. Moreover, we found that leptin induces rearrangement of actin microfilaments, leading to uropod and ruffle formation. Here we monitor the effects of leptin on DC migratory capacities, focusing on the intracellular signaling driving cytoskeleton rearrangement. We found that leptin increases immature DC migratory performance both by favoring cytoskeleton dynamics and by up-regulating CCR7 surface expression, thus favoring chemotactic responsiveness. We found that in immature DCs, leptin activates cofilin, favoring the turnover of actin microfilaments, and, by triggering Vav phosphorylation, promotes Rac1 activation. Finally, we found that in immature DCs, leptin up-regulates interleukin-12p70 production on CD40 stimulation and, more importantly, increases their capacity to stimulate activation of autologous CD8(+) T cells. Taken altogether, the findings herein highlight the potential use of leptin as an adjuvant tool in vaccination protocols employing ex vivo-generated autologous DCs.