Dendritic cell function in the setting of chronic hepatitis c infection and changes during antiviral treatment

The role of the innate immune system and in particular of dendritic cells, in the establishment of chronic hepatitis C has been studied quite extensively over the last few years but controversy remains as to whether a potential virus-induced defect in DC function leads to sub-optimal initiation of adaptive immune responses and finally to the establishment of chronic infection. In the present thesis we examined monocyte-derived DC (MDDC), generated from patients with chronic hepatitis C (CHC), and healthy subjects in order to gain a better understanding of dendritic cell functions in the setting of hepatitis C infection. We initially observed a defect in CHC patients’ DC capacity to stimulate ‘naïve’ CD4+ T-cells into proliferation. Investigating for factors potentially contributing to this defect we demonstrated that HCV genome (both positive strand HCV RNA and the replicative intermediate negative strand HCV RNA) and HCV protein products (HCV core protein) are present in DC without though any obvious correlation to DC functions. We further proccedeed to investigate for potential influence of other, host-related, parameters on DC and tested liver fibrosis, ethanol consumption, HCV viraemia levels and HCV protein products’ concentration in the serum demonstarting significant influences of HCV viraemia / HCV core serum concentration and ethanol consumption on DC functional and phenotypic output. After successful antiviral treatment (with pegylated interferon α and ribavirin) our patients restored their DC functions (allostimulatory capacity, HCV-specific immune-reactivity and IL-12production). Performing ‘cross-over’ experiments we suggest that antiviral treatment exerted its effect by improving mainly DC capacities and not effector CD4+ T-cell reactivity. We also tested plasmacytoid dendritic cell cytokine output after HCV infection and we observed a controversial effect of the virus on the Th1-skewing capacity of this DC subset

Co-existence of a giant splenic hemangioma and multiple hepatic hemangiomas and the potential association with the use of oral contraceptives: a case report

<p>Abstract</p> <p>Introduction</p> <p>Hepatic and splenic hemangiomas are common benign tumors that mainly affect female patients. Giant splenic hemangiomas are extremely rare, especially when correlated with multiple hepatic hemangiomas. Pathogenetic mechanisms between hemangiomas and oral contraceptives, as well as therapeutic approaches, are analyzed in this case report, in particular for the management of synchronous splenic and hepatic hemangiomas.</p> <p>Case presentation</p> <p>We report here a 42-year-old woman with a giant splenic hemangioma, multiple hepatic hemangiomas and a history of oral estrogen intake for many years. At first it was difficult to determine the organ from which the giant hemangioma originated. Angiography proved extremely helpful in tracing its origin in the spleen. Hematomas in the giant hemangioma posed a significant threat of rupture and catastrophic hemorrhage. We left the small hepatic hemangiomas in place, and removed the spleen along with the giant splenic hemangioma.</p> <p>Conclusion</p> <p>Diagnostic pitfalls in the determination of the origin of this giant hemangioma, attribution of its origin to the spleen angiographically, the unusual co-existence of the giant splenic hemangioma with multiple hepatic ones, and the potential threat of rupture of the giant hemangioma are some of the highlights of this case report. Estrogen administration represents a pathogenic factor that has been associated with hemangiomas in solid organs of the abdominal cavity. The therapeutic dilemma between resection and embolization of giant hemangiomas is another point of discussion in this case report. Splenectomy for the giant splenic hemangioma eliminates the risk of rupture and malignant degeneration, whereas observation for the small hepatic ones (<4 cm) was the preferable therapeutic strategy in our patient.</p

Mirizzi syndrome type IV associated with cholecystocolic fistula: a very rare condition- report of a case

<p>Abstract</p> <p>Background</p> <p>Mirizzi syndrome is a rare complication of prolonged cholelithiasis with presence of large, impacted gallstone into the Hartman's pouch, causing chronic extrinsic compression of common bile duct (CBD). Fistula formation between the CBD and the gallbladder may represent an outcome of that condition. According to Mirizzi's classification and Csendes's subclassification, Mirizzi syndrome type IV represents the most uncommon type (4%).</p> <p>Spontaneous biliary-enteric fistulas have also been rarely reported (1.2–5%) in a large series of cholecystectomies. Cholecystocolic fistula is the most infrequent biliary enteric fistula, causing significant morbidity and representing a diagnostic challenge.</p> <p>Case presentation</p> <p>We describe a very rare, to our knowledge, combination of Mirizzi syndrome type IV and cholecystocolic fistula. A 52 year old male, presented to our clinic complaining of episodic diarrhea (monthly episodes lasting 16 days), high temperature (38°C–39°C), right upper quadrant pain without jaundice. The definitive diagnosis was made intraoperatively. Magnetic Resonance Imaging (MRI) and Endoscopic Retrograde Cholangiopancreatography (ERCP) demonstrated the presence of Mirizzi syndrome with cholecystocolic fistula formation. The patient was operated upon, and cholecystectomy, cholecystocolic fistula excision and Roux-en-Y biliary-enteric anastomosis were undertaken with excellent post-operative course.</p> <p>Conclusion</p> <p>Appropriate biliary tree imaging with ERCP and MRI/MRCP is essential for the diagnosis of Mirizzi syndrome and its complications. Cholecystectomy, fistula excision and biliary-enteric anastomosis with Roux-en-Y loop appears to be the most appropriate surgical intervention in order to avoid damage to Calot's triangle anatomic elements. Particularly in our case, ERCP was a valuable diagnostic tool that Mirizzi syndrome type IV and cholecystocolic fistula.</p

Network-Based Pipeline for Analyzing MS Data: An Application toward Liver Cancer

10.1021/pr1010845Journal of Proteome Research1052261-2272JPRO

IL28B genetic variations are associated with high sustained virological response (SVR) of interferon-α plus ribavirin therapy in Taiwanese chronic HCV infection

Chronic hepatitis C virus (HCV) infection patients exhibit different sustained virological responses (SVRs) following the treatment with pegylated interferon-α (IFN-α) and ribavirin. Genome-wide association studies consistently linked SVR of IFN-α-based therapy to the IL28B single-nucleotide polymorphisms (SNPs) on chromosome 19q.13 in various populations. This study was undertaken to investigate the association of IL28B SNPs with SVR in a cohort of Taiwanese chronic HCV patients. Ten SNPs of IL28B were genotyped in 728 chronic HCV patients and 960 healthy controls. Genotype distributions, allele frequencies and haplotypes were tested for SVR and susceptibility in Taiwanese chronic HCV patients. Non-genotype 1 infection (adjusted P=3.3 × 10−12, odds ratio (OR) 0.179; 95% confidence interval (CI): 0.110–0.290) and low HCV viral load (<400 000 IU ml–1) (adjusted P=3.5 × 10−9, OR 0.299; 95% CI: 0.200–0.446) were two major factors identified for high SVR. Notably, eight IL28B SNPs including previously described disease-associated SNPs (Trend test P=0.005) were significantly associated with SVR. Our data indicate that IL28B polymorphisms are the essential contributing factors for high SVR in Taiwanese chronic HCV patients. Combination of virus genotyping and host genetic data may be used to select the optimal treatment regimes in IFN-based therapy

Dendritic cell function in the setting of chronic hepatitis c infection and changes during antiviral treatment .

The role of the innate immune system and in particular of dendritic cells, in the establishment of chronic hepatitis C has been studied quite extensively over the last few years but controversy remains as to whether a potential virus-induced defect in DC function leads to sub-optimal initiation of adaptive immune responses and finally to the establishment of chronic infection. In the present thesis we examined monocyte-derived DC (MDDC), generated from patients with chronic hepatitis C (CHC), and healthy subjects in order to gain a better understanding of dendritic cell functions in the setting of hepatitis C infection. We initially observed a defect in CHC patients’ DC capacity to stimulate ‘naïve’ CD4+ T-cells into proliferation. Investigating for factors potentially contributing to this defect we demonstrated that HCV genome (both positive strand HCV RNA and the replicative intermediate negative strand HCV RNA) and HCV protein products (HCV core protein) are present in DC without though any obvious correlation to DC functions. We further proccedeed to investigate for potential influence of other, host-related, parameters on DC and tested liver fibrosis, ethanol consumption, HCV viraemia levels and HCV protein products’ concentration in the serum demonstarting significant influences of HCV viraemia / HCV core serum concentration and ethanol consumption on DC functional and phenotypic output. After successful antiviral treatment (with pegylated interferon α and ribavirin) our patients restored their DC functions (allostimulatory capacity, HCV-specific immune-reactivity and IL-12production). Performing ‘cross-over’ experiments we suggest that antiviral treatment exerted its effect by improving mainly DC capacities and not effector CD4+ T-cell reactivity. We also tested plasmacytoid dendritic cell cytokine output after HCV infection and we observed a controversial effect of the virus on the Th1-skewing capacity of this DC subset.

The role of dendritic cells in the chronicity of hepatitis C

In the present thesis we examined the functions of monocyte-derived DC (MDDC), generated from patients with chronic hepatitis C (CHC), against the same parameters of DC generated from healthy subjects. We observed a defect in DC, generated from CHC patients, capacity to stimulate ‘naïve’ CD4+ T-cells into proliferation, in Mixed Lymphocyte Reactions (MLR). We further investigated other parameters of DC function and in particular, the production of IL-12, the expression on DC surface of CD40, CD80, CD83, CD86, HLA DR and we tried to correlate them with virus- and patient- specific characteristics. We observed statistically significant stimulatory effect of HCV viraemia and antigenaemia on DC immune-phenotype and on DC allostimulatory capacity. The presence of HCV specific sequences and in particular “positive” and “negative” strand HCV RNA and of HCV proteins (HCV core) inside the DC did not appear to influence DC function. A negative effect on DC IL-12 secretion was seen in “heavy drinkers” (>24units of ethanol/week). We further studied the effect of the anti-viral treatment on DC function, assuming restoration of DC reactivity as a result of therapy. We observed increased induction of IFN-γ production from autologous CD4+ T-lymphocytes in patients achieving undetectable viraemia by treatment week 12 and we showed evidence, by implementing “cross-over” experiments, that the observed improvement in autologous reactivity was possibly due to DC function restoration post-treatment. In a quite crude first attempt at accessing plasmacytoid dendritic cell (pDC) contribution to anti-HCV immunity we infected pDC from healthy donors with HCV plasma and we subsequently tested their capacity to produce various cytokines both Th1 and Th2-skewing, namely: IFN-α, IL-6 and IL-12 as compared to cytokine secretion elicited by “positive” markers: a. TLR 7/8 ligand), b. HBV serum and c. TLR 9 ligand . We showed evidence of simultaneous induction of IFN-α secretion and reduced IL-12 production related to HCV infection. Testing the effect of antiviral drug Ribavirin on pDC we came across a spectacular induction of IL-12 secretion, for the first time in the literature, adding one more potential mechanism of the antiviral capacity of the drug. In summary our data overall: 1. add evidence to the negative effect of HCV on DC function, 2. indicate improvement of DC function as a result of viraemia clearance after antiviral treatment, an improvement that eventually restores adaptive antiviral responses, 3. point towards low-grade active HCV replication inside DC without an effect on DC function, probably as a trick HCV uses to escape antiviral immunity by exploiting the “immunological safe-haven” of the DC endosomal compartments, 4. show induction of IFN-a production along with reduced IL-12production by pDC in the setting of HCV infection and finally 5. indicate one more potential mechanism of the antiviral effect of Ribavirin that of IL-12 induction from pDC.Ο ρόλος του ενδογενούς ανοσιακού συστήματος και ιδιαίτερα των δενδριτικών κυττάρων στην εγκατάσταση χρόνιας ηπατίτιδας C, έχει μελετηθεί τα τελευταία χρόνια. Ωστόσο δεν υπάρχει συμφωνία σχετικά με πιθανή δυσλειτουργία των δενδριτικών κυττάρων στα πλαίσια της HCV λοίμωξης. Στην παρούσα διατριβή αρχικά παρατηρήσαμε έλλειμμα στην ικανότητα των DC από ασθενείς με χρόνια ηπατίτιδα C να προάγουν τον πολλαπλασιασμό “naïve” CD4+ T-λεμφοκυττάρων. Χρησιμοποιώντας ως αφετηρία αυτή την παρατήρησή μας μελετήσαμε περαιτέρω και άλλες λειτουργικές παραμέτρους των DC όπως η έκκριση IL-12 και η έκφραση επί των DC CD40, CD80, CD83, CD86, και HLA DR, αναζητώντας παράγοντες σχετιζόμενους με τον HCV ή με τα χαρακτηριστικά των μελετηθέντων ασθενών που επηρεάζουν τις παραμέτρους αυτές. Διαπιστώσαμε στατιστικά σημαντική διεγερτική επίδραση της HCV ιαιμίας και αντιγοναιμίας επί του ανοσοφαινότυπου των DC αλλά και επί της αλλοδιεγερτικής ικανότητας τους. Αντίθετα η παρουσία HCV γονιδιώματος αλλά και αντιγόνων του ιού εντός των DC δεν φάνηκε στα πειράματά μας να επηρεάζει τη λειτουργία των τελευταίων. Αρνητική επίδραση επί της έκκρισης IL-12 από τα DC παρατηρήσαμε σε ασθενείς με αυξημένη κατανάλωση αλκοόλ. Επίσης μελετήσαμε την επίδραση της αντι-ιϊκής θεραπείας επί της λειτουργικότητας των DC με την υπόθεση της βελτίωσής της μετά τον φαρμακευτικό έλεγχο της ιαιμίας. Όντως σε ασθενείς που πέτυχαν μη-ανιχνεύσιμα επίπεδα του HCV μέχρι τη 12η εβδομάδα της θεραπείας παρατηρήσαμε αυξημένη ικανότητα παραγωγής και έκκρισης IFN-γ από αυτόλογα CD4+ T-λεμφοκύτταρα. Για να διαχωρίσουμε ωστόσο τη συμβολή της βελτίωσης της λειτουργικότητας των DC από τη θεραπεία έναντι της βελτίωσης της επίκτητης ανοσίας δοκιμάσαμε DC και CD4+ T-λεμφοκύτταρα πριν και μετά τη θεραπεία, σε συν-καλλιέργειες, σε όλους τους δυνατούς συνδυασμούς, σε ασθενείς οι οποίοι εμφάνισαν μη-ανιχνεύσιμο HCV RNA στο τέλος της 12ης εβδομάδας της θεραπείας. Από αυτά τα πειράματά μας προέκυψαν σημαντικές ενδείξεις βελτίωσης της λειτουργικότητας των DC και όχι των CD4+ Τ-λεμφοκυττάρων. Σε μια αρχική απόπειρα εκτίμησης της συμβολής των pDC στην αντι-HCV ανοσία επιμολύναμε pDC από υγιείς εθελοντές με πλάσμα ασθενούς με υψηλή HCV ιαιμία και μελετήσαμε την έκκριση IFN-α, IL-6 και IL-12 από αυτά συγκρίνοντάς την με την αντίστοιχη έκκριση που προκλήθηκε από a. TLR 7/8 ligand, b. ορό ασθενούς με υψηλή HBV ιαιμία και c. TLR 9 ligand. Διαπιστώσαμε ενδείξεις κατασταλτικής επίδρασης από την μία μεριά επί της έκκρισης IL-12p70 και από την άλλη επαγωγικής της έκκρισης IFN-α, από τον HCV. Τέλος μελετήσαμε την επίδραση της Ριμπαβιρίνης επί των pDC και αναγνωρίσαμε για πρώτη φορά στη βιβλιογραφία την διεγερτική επίδραση θεραπευτικών συγκεντρώσεων Ριμπαβιρίνης επί της έκκρισης IL-12. Επιγραμματικά θα μπορούσαμε να πούμε ότι τα δεδομένα της παρούσας διατριβής προσθέτουν μαρτυρία: 1. στον αρνητικό επηρεασμό της λειτουργίας των DC από τον HCV, 2. στην αποκατάσταση της λειτουργίας των DC στα πλαίσια της αντιϊκής θεραπείας και στην επακόλουθη βελτίωση της επίκτητης αντι-HCV ανοσίας, 3.στην παρατήρηση ότι η παρουσία του ιού εντός των DC δεν επηρεάζει τη λειτουργία τους, 4. στην επαγωγή έκκρισης IFN-α και στην μειωμένη έκκριση IL-12 από τα pDC στα πλαίσια της λοίμωξης από τον HCV και τέλος 5. αναδεικνύουν για πρώτη φορά στη βιβλιογραφία την ευεργετική επίδραση της αντι-ιϊκής θεραπείας, και συγκεκριμένα της Ριμπαβιρίνης, επί των pDC και ιδιαίτερα επί της έκκρισης IL-12 από τα τελευταία