Eric T. Tjwa

Viral load reduction improves activation and function of natural killer cells in patients with chronic hepatitis B

BACKGROUND & AIMS Natural killer (NK) cells play a major role in anti-viral immunity as first line defense and regulation of virus-specific T cell responses. This study aimed to investigate phenotype and function of NK cells in patients with chronic hepatitis B virus (HBV) infection and to study the effect of anti-viral therapy. METHODS Peripheral blood NK cells from 40 chronic HBV patients were compared to NK cells of 25 healthy controls. The effect of entecavir-induced viral load reduction on NK cell phenotype and function was investigated in 15 chronic HBV patients. RESULTS NK cell numbers and subset distribution did not differ between HBV patients and normal subjects. In chronic HBV patients, the cytotoxic capacity was retained, but NK cell activation and subsequent IFNγ and TNFα production, especially of the CD56(dim) subset, were strongly hampered. This functional dichotomy was paralleled by an altered activation state, elevated expression of NKG2A, and downregulated expression of CD16 and NKp30, which correlated with serum HBV-DNA load. Anti-viral therapy partially restored NK cell phenotype, as shown by NKG2A downregulation. Moreover, viral replication inhibition improved IFNγ production as a result of an increased ability of CD56(dim) NK cells to become activated de novo. This improved NK cell activation and function which correlated with therapy-induced reduction in serum ALT levels, but not HBV-DNA load. CONCLUSIONS The specific defect in CD56(dim) NK cell activation and the reduced capacity to produce anti-viral and Th1-skewing cytokines may play a role in HBV persistence. Restoration of this NK cell cytokine-producing capacity, as achieved by viral load reduction, could therefore contribute to definite clearance of the virus.

Hemospray Application in Nonvariceal Upper Gastrointestinal Bleeding: Results of the Survey to Evaluate the Application of Hemospray in the Luminal Tract.

Background: Hemospray TM (TC-325) is a novel hemostatic agent licensed for use in nonvariceal upper gastrointestinal bleeding (NVUGIB) in Europe. Goals: We present the operating characteristics and performance of TC-325 in the largest registry to date of patients presenting with NVUGIB in everyday clinical practice. Methods: Prospective anonymized data of device performance and clinical outcomes were collected from 10 European centers using the multicentre SEAL survey (Survey to Evaluate the Application of Hemospray in the Luminal tract). TC-325 was used as a monotherapy or as second-line therapy in combination with other hemostatic modalities at the endoscopists’ discretion. Results: Sixty-three patients (44 men, 19 women), median age 69 (range, 21 to 98) years with NVUGIB requiring endoscopic hemostasis were treated with TC-325. There were 30 patients with bleeding ulcers and 33 with other NVUGIB pathology. Fifty-five (87%) were treated with TC-325 as monotherapy; 47 [85%; 95% confidence interval (CI), 76%-94%] of them achieved primary hemostasis, and rebleeding rate at 7 days was 15% (95% CI, 5%-25%). Primary hemostasis rate for TC-325 in patients with ulcer bleeds was 76% (95% CI, 59%-93%). Eight patients, who otherwise may have required either surgery or interventional radiology, were treated with TC-325 as second-line therapy after failure of other endoscopic treatments, all of whom achieved hemostasis following the adjunct of TC-325. Conclusions: This multicentre registry identifies potentially useful characteristics of Hemospray (TC-325) when used either as monotherapy or as a rescue therapy in a wide variety of ulcer and nonulcer NVUGIB.

Hemospray in the treatment of upper gastrointestinal hemorrhage in patients on antithrombotic therapy

Patients on antithrombotic therapy (ATT) have the highest risk of ongoing bleeding and mortality. Hemospray (Cook Medical, Winston-Salem, North Carolina, USA) is a novel hemostatic agent for the treatment of upper gastrointestinal bleeding (UGIB). Initial reports on its use appear promising in terms of initial hemostasis and rebleeding rates. It is unknown whether this also pertains to patients on ATT. The aim of the current study therefore was to evaluate the efficacy of Hemospray in the treatment of UGIB in patients taking ATTs. A total of 16 unselected consecutive patients with UGIB who were treated with Hemospray were analyzed (eight taking ATT for various indications and eight not on ATT). Initial hemostasis was achieved after Hemospray application in 5 /8 patients on ATT (63 %) and in all eight patients not on therapy (P = 0.20). Rebleeding rates were similar in both groups. These preliminary data on the use of Hemospray in the management of UGIB are promising in both patients with and without ATT; however, caution should be exercised for its use in patients on ATT with spurting arterial bleeding.

Covered transjugular intrahepatic portosystemic shunt versus endoscopic therapy + β‐blocker for prevention of variceal rebleeding

Gastroesophageal variceal bleeding in patients with cirrhosis is associated with significant morbidity and mortality, as well as a high rebleeding risk. Limited data are available on the role of transjugular intrahepatic portosystemic shunt (TIPS) with covered stents in patients receiving standard endoscopic, vasoactive, and antibiotic treatment. In this multicenter randomized trial, long‐term endoscopic variceal ligation (EVL) or glue injection + β‐blocker treatment was compared with TIPS placement in 72 patients with a first or second episode of gastric and/or esophageal variceal bleeding, after hemodynamic stabilization upon endoscopic, vasoactive, and antibiotic treatment. Randomization was stratified according to Child‐Pugh score. Kaplan‐Meier (event‐free) survival estimates were used for the endpoints rebleeding, death, treatment failure, and hepatic encephalopathy. During a median follow‐up of 23 months, 10 (29%) of 35 patients in the endoscopy + β‐blocker group, as compared to 0 of 37 (0%) patients in the TIPS group, developed variceal rebleeding (P = 0.001). Mortality (TIPS 32% vs. endoscopy 26%; P = 0.418) and treatment failure (TIPS 38% vs. endoscopy 34%; P = 0.685) did not differ between groups. Early hepatic encephalopathy (within 1 year) was significantly more frequent in the TIPS group (35% vs. 14%; P = 0.035), but during long‐term follow‐up this difference diminished (38% vs. 23%; P = 0.121). Conclusions: In unselected patients with cirrhosis, who underwent successful endoscopic hemostasis for variceal bleeding, covered TIPS was superior to EVL + β‐blocker for reduction of variceal rebleeding, but did not improve survival. TIPS was associated with higher rates of early hepatic encephalopathy. (Hepatology 2016;63:581–589)

Controlling gastric variceal bleeding with endoscopically applied hemostatic powder (HemosprayTM)

To the Editor: Gastric variceal bleeding tends to be more severe (2.9 vs. 4.8 transfusion units per patient) and is associated with a higher mortality (30% vs. 45%) than bleeding from oesophageal varices [1–3]. Failure of endoscopic therapy commonly requires rescue placement of a transjugular intrahepatic portosystemic shunt (TIPS) [4], but this option is costly and not always feasible. Hemospray is a novel hemostatic spray recently introduced for the management of non-variceal upper gastrointestinal bleeding [5]. We describe the first case of variceal bleeding refractory to standard endoscopic therapy, successfully treated with Hemospray, obviating the need for TIPS. A 79-year-old woman presented to the emergency department with a 3-day history of melena. Her previous medical history included idiopathic myelofibrosis with hepatosplenomegaly due to extramedullary hematopoiesis. This was complicated by portal hypertension and ascites. Furthermore, she suffered from a severe hypertension-related pre-existent dilated cardiomyopathy. Previous upper endoscopy did not show the presence of varices. At presentation she had a blood pressure of 80/40 mmHg with a pulse rate of 90 bpm with peripheral cyanosis. On rectal examination, black stools were noticed. Laboratory test results showed haemoglobin 4.8 mmol/L, urea 27 mmol/L, creatinine 68 mmol/L, INR 1.4, and normal transaminases and bilirubin. In anticipation of a variceal haemorrhage, standard administration of an antibiotic (norfloxacin 400 mg twice daily) and vasopressor drugs (octreotide) was initiated. Fluid and packed cell administration was restricted to stabilize vital signs. The patient was meanwhile transferred to the intensive care unit. Upper gastrointestinal endoscopy was performed using an Olympus Q180-1T scope (Olympus, Japan). In the distal esophagus, small varices without bleeding stigmata were seen, but in the gastric fundus, a profusely bleeding varix of 8 mm (GOV2 [2]) was observed. Next, in three consecutive injections, a total volume of 2.6 ml HistoAcryl with lipiodol was injected. However, hemostasis could not be achieved and hemodynamic instability ensued. Rescue treatment with TIPS was considered, but not pursued given her cardiac condition. Instead of injecting more HistoAcryl, we decided to apply Hemospray (Cook Medical, USA). For this, we sprayed approximately 10 g of Hemospray covering the entire bleeding varix. Persistent hemostasis was confirmed after 5 min of visual inspection. The patient received standard post-endoscopic care and went home. No rebleeding occurred at follow-up at day 7 and 30. We did not perform a second-look endoscopy given the absence of signs of rebleeding. Gastric variceal haemorrhage is an acute life-threatening condition in which the endoscopist is challenged to act swift in a technically demanding retroflexed position. Endoscopic management involves single or multiple injection(s) of cyanoacrylate glue into

Covered TIPS vs endoscopic therapy + Β‐blocker for prevention of variceal rebleeding

Gastroesophageal variceal bleeding in patients with cirrhosis is associated with significant morbidity and mortality, as well as a high rebleeding risk. Limited data are available on the role of transjugular intrahepatic portosystemic shunt (TIPS) with covered stents in patients receiving standard endoscopic, vasoactive, and antibiotic treatment. In this multicenter randomized trial, long‐term endoscopic variceal ligation (EVL) or glue injection + β‐blocker treatment was compared with TIPS placement in 72 patients with a first or second episode of gastric and/or esophageal variceal bleeding, after hemodynamic stabilization upon endoscopic, vasoactive, and antibiotic treatment. Randomization was stratified according to Child‐Pugh score. Kaplan‐Meier (event‐free) survival estimates were used for the endpoints rebleeding, death, treatment failure, and hepatic encephalopathy. During a median follow‐up of 23 months, 10 (29%) of 35 patients in the endoscopy + β‐blocker group, as compared to 0 of 37 (0%) patients in the TIPS group, developed variceal rebleeding (P = 0.001). Mortality (TIPS 32% vs. endoscopy 26%; P = 0.418) and treatment failure (TIPS 38% vs. endoscopy 34%; P = 0.685) did not differ between groups. Early hepatic encephalopathy (within 1 year) was significantly more frequent in the TIPS group (35% vs. 14%; P = 0.035), but during long‐term follow‐up this difference diminished (38% vs. 23%; P = 0.121). Conclusions: In unselected patients with cirrhosis, who underwent successful endoscopic hemostasis for variceal bleeding, covered TIPS was superior to EVL + β‐blocker for reduction of variceal rebleeding, but did not improve survival. TIPS was associated with higher rates of early hepatic encephalopathy. (Hepatology 2016;63:581–589)

Hemospray treatment is effective for lower gastrointestinal bleeding

Acute lower gastrointestinal bleeding (LGIB) is diverse in origin and can be substantial, requiring urgent hemostasis. Hemospray is a promising novel hemostatic agent for upper gastrointestinal bleeding (UGIB). It has been claimed in a small series that the use of Hemospray is also feasible in LGIB. We aimed to expand our knowledge of the application of Hemospray for the treatment of LGIB in a wider range of conditions to further define the optimal patient population for this new therapeutic modality. We analyzed the outcomes of nine unselected consecutive patients with active LGIB treated with Hemospray in two major hospitals in Europe. Initial hemostasis was achieved after Hemospray application in all patients. Rebleeding occurred in two patients (22%) who were on acetyl salicylic acid and presented with spurting bleeds. These preliminary data show that Hemospray can be effective in the management of LGIB, but suggest cautious use for patients on antithrombotic therapy and spurting bleeds.

Hepatitis B virus suppresses the functional interaction between natural killer cells and plasmacytoid dendritic cells

Summary.  Natural killer cells (NK) are one of the key players in the eradication and control of viral infections. Infections with the hepatitis B virus (HBV) may lead to persistence in a subgroup of patients, and impaired NK cell functions have been observed in these patients. Crosstalk with other immune cells has been shown to modulate the function of NK cells. We studied the functional crosstalk between NK cells and plasmacytoid dendritic cell (pDC) and its modulation by HBV. Healthy human peripheral blood–derived NK cells and pDC were purified and cocultured in the presence or absence of HepG2.2.15‐derived HBV under various in vitro conditions. The functionality of NK cells was assessed by evaluation of activation markers, cytokine production and cytotoxicity of carboxyfluorescein succinimidyl ester‐labelled K562 target cells by flow cytometry or immunoassays. Additionally, the crosstalk was examined using NK and pDC from patients with chronic HBV. The activation of NK cells in cocultures with pDC, as demonstrated by CD69, CD25 and HLA‐DR, was not affected by the presence of HBV. Similarly, when cocultured with pDC, the cytotoxic potential of NK cells was not influenced by HBV. However, HBV significantly inhibited pDC‐induced IFN‐γ production by NK cells both in the presence and in the absence of CpG. As HBV did not affect cytokine‐induced IFN‐γ production by NK cells cultured alone, the suppressive effect of HBV on NK cell function was mediated via interference with pDC–NK cell interaction. In contrast to other viruses, HBV does not activate pDC–NK cell interaction but inhibits pDC‐induced NK cell function. In parallel with NK cells of patients with chronic HBV, which show diminished cytokine production with normal cytotoxicity, HBV specifically suppressed pDC‐induced IFN‐γ production by NK cells without affecting their cytolytic ability. These data demonstrate that HBV modulates pDC–NK cell crosstalk, which may contribute to HBV persistence.

Self-expandable metal stents as definitive treatment for esophageal variceal bleeding.

The use of self-expandable metal stents (SEMS) has occasionally been described for the treatment of uncontrollable esophageal variceal bleeding (EVB) as a bridge to an alternative treatment option (i. e. transjugular intrahepatic portosystemic shunt [TIPS]). It is currently not known whether SEMS placement is appropriate for more than temporary hemostasis. This case series report describes five patients in whom EVB could not be controlled with variceal band ligation and who were not suitable to undergo a TIPS procedure at the time of bleeding. SEMS were placed in these patients with the intent of definitive treatment. Successful initial hemostasis was achieved in all five patients, and sustained hemostasis occurred in four. Stents were removed from two patients after > 14 days and remained in situ until death in three other patients (range 6 - 214 days). No complications related to this longer duration were observed. In one case, TIPS could be performed at a later stage. SEMS could be a definitive treatment for uncontrollable esophageal bleeding in patients with a limited life expectancy or those unsuitable for TIPS at the time of bleeding.

Restoration of TLR3-activated myeloid dendritic cell activity leads to improved natural killer cell function in chronic hepatitis B virus infection

ABSTRACT There is increasing evidence that the function of NK cells in patients with chronic hepatitis B (CHB) infection is impaired. The underlying mechanism for the impaired NK cell function is still unknown. Since myeloid dendritic cells (mDC) are potent inducers of NK cells, we investigated the functional interaction of mDC and NK cells in CHB and the influence of antiviral therapy. Blood BDCA1+ mDC and NK cells were isolated from 16 healthy controls or 39 CHB patients at baseline and during 6 months of antiviral therapy. After activation of mDC with poly(I · C) and gamma interferon (IFN-γ), mDC were cocultured with NK cells. Phenotype and function were analyzed in detail by flow cytometry and enzyme-linked immunosorbent assay. Our findings demonstrate that on poly(I · C)/IFN-γ-stimulated mDC from CHB patients, the expression of costimulatory molecules was enhanced, while cytokine production was reduced. In cocultures of poly(I · C)/IFN-γ-stimulated mDC and NK cells obtained from CHB patients, reduced mDC-induced NK cell activation (i.e., CD69 expression) and IFN-γ production compared to those in healthy individuals was observed. Antiviral therapy normalized mDC activity, since decreased expression of CD80 and CD86 on DC and of HLA-E on NK cells was observed, while poly(I · C)/IFN-γ-induced cytokine production by mDC was enhanced. In parallel, successful antiviral therapy resulted in improved mDC-induced NK cell activation and IFN-γ production. These data demonstrate that CHB patients display a diminished functional interaction between poly(I · C)/IFN-γ activated mDC and NK cells due to impaired mDC function, which can be partially restored by antiviral therapy. Enhancing this reciprocal interaction could reinforce the innate and thus the adaptive T cell response, and this may be an important step in achieving effective antiviral immunity.