Persisting dental foci increase the risk for bacterial infections before and after liver transplant.

BACKGROUND: Patients awaiting liver transplant are usually assessed for presence of dental foci to prevent bacterial infection post-transplant, but evidence to support dental examination and treatment is limited. We investigated if treatment of dental foci decreased bacterial infections before and after transplant. METHODS: Patients transplanted at the university hospital of Bonn were retrospectively assessed for occurrence of bacterial infections before and after transplant according to presence and treatment of dental foci. RESULTS: 35/110 patients showed good oral health, 39/110 patients received dental care and 36/110 patients did not receive dental care despite poor oral health. Patients with alcohol-associated liver disease presented with the highest rate of dental foci. Bleeding complications due to oral care occurred in five patients with poor coagulation. After transplant, the number of infections per patient was higher in patients with poor oral health (2.9) compared to patients after dental care (1.9) or with good oral health (1.8) (p = .02), with streptococcal infections being more frequent in patients with poor oral health. Before transplant, bacterial infections, in particular bacteraemia and spontaneous bacterial peritonitis, were also more common in patients with untreated dental foci. Streptococci and Staphylococci were more often detected in patients with dental foci. Dental treatment was associated with a reduction in bacterial infections. CONCLUSION: Presence of dental foci is associated with an increased risk for bacterial infections not only after but also before liver transplant. Dental treatment might be a safe and effective procedure to mitigate this risk.

Role of the NK cell-activating receptor CRACC in periodontitis.

Periodontitis is a highly prevalent, biofilm-mediated chronic inflammatory disease that results in the loss of the tooth-supporting tissues. It features two major clinical entities: chronic periodontitis, which is more common, and aggressive periodontitis, which usually has an early onset and a rapid progression. Natural killer (NK) cells are a distinct subgroup of lymphocytes that play a major role in the ability of the innate immune system to steer immune responses. NK cells are abundant in periodontitis lesions, and NK cell activation has been causally linked to periodontal tissue destruction. However, the exact mechanisms of their activation and their role in the pathophysiology of periodontitis are elusive. Here, we show that the predominant NK cell-activating molecule in periodontitis is CD2-like receptor activating cytotoxic cells (CRACC). We show that CRACC induction was significantly more pronounced in aggressive than chronic periodontitis and correlated positively with periodontal disease severity, subgingival levels of specific periodontal pathogens, and NK cell activation in vivo. We delineate how Aggregatibacter actinomycetemcomitans, an oral pathogen that is causally associated with aggressive periodontitis, indirectly induces CRACC on NK cells via activation of dendritic cells and subsequent interleukin 12 (IL-12) signaling. In contrast, we demonstrate that fimbriae from Porphyromonas gingivalis, a principal pathogen in chronic periodontitis, actively attenuate CRACC induction on NK cells. Our data suggest an involvement of CRACC-mediated NK cell activation in periodontal tissue destruction and point to a plausible distinction in the pathobiology of aggressive and chronic periodontitis that may help explain the accelerated tissue destruction in aggressive periodontitis.

NK cells from HCV-infected patients effectively induce apoptosis of activated primary human hepatic stellate cells in a TRAIL-, FasL- and NKG2D-dependent manner.

In mouse models it has been shown that natural killer (NK) cells can attenuate liver fibrosis via killing of activated hepatic stellate cells (HSCs) in a NKG2D- and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-dependent manner. However, only little data exist regarding interactions of human NK cells with HSCs and their potential role in hepatitis C virus (HCV)-associated fibrogenesis. Therefore, purified NK cells from untreated HCV RNA(+) patients (n=33), interferon-α (IFN-α)-treated patients (n=17) and healthy controls (n=18) were coincubated with activated primary HSCs, and were tested for degranulation (CD107a expression) and secretion of IFN-γ and TNF-α, respectively. Induction of HSC apoptosis was analyzed using an active caspase-3 assay. We found that following coincubation with HSCs a significant increase in CD107a expression could be observed in both NK cells from HCV(+) patients and healthy controls, whereas only negligible secretion of IFN-γ and TNF-α could be detected. More importantly, NK cells from untreated HCV RNA(+) patients were significantly more effective in induction of HSC apoptosis (17.8 ± 9.2%) than NK cells from healthy controls (6.2 ± 2.1%; P<0.0001). Additionally, we observed an inverse correlation of liver fibrosis stage and the ability of NK cells to induce HSC apoptosis. Induction of HSC apoptosis was contact dependent and could partly be blocked by antibodies specific for TRAIL, NKG2D and FasL, respectively. It is noteworthy that NK cells from IFN-α-treated HCV(+) patients displayed the highest capability to kill HSCs (27.6 ± 10.5%). Accordingly, pre-stimulation of NK cells with recombinant IFN-α significantly increased the ability of NK cells to induce cell death in primary HSCs and was dependent on upregulated expression of TRAIL. Here we demonstrate that NK cells from HCV-infected patients are highly efficient in inducing apoptosis of activated HSCs. Thus, NK cells may have an important anti-fibrotic role in chronic hepatitis C.

Prediction of response to pegylated interferon plus ribavirin in HIV/hepatitis C virus (HCV)-coinfected patients using HCV genotype, IL28B variations, and HCV-RNA load.

BACKGROUND & AIMS: This study aimed at developing a predictive algorithm based on interleukin 28B (IL28B) genotype, hepatitis C virus (HCV) genotype, and plasma HCV-RNA load, which could accurately allow us to define the probability of response to pegylated interferon (Peg-IFN) plus ribavirin (RBV) therapy in HIV/HCV-coinfected patients. METHODS: Five hundred and twenty-one treatment-naive HIV-infected patients, who initiated HCV therapy with Peg-IFN/RBV, were analysed in an on-treatment basis. Patients were categorized as unlikely responders, uncertain responders, and anticipated responders (<20%, 20-60%, and >60% probability to achieve SVR, respectively). RESULTS: HCV genotype, baseline HCV-RNA load, and IL28B genotype were confirmed as independent predictors of SVR in a logistic regression analysis. A stepwise algorithm based on these three variables was created based on 321 patients and evaluated in the remaining 200 patients. Unlikely responders included patients with genotype 1 or 4, HCV-RNA load ≥600,000IU/ml, and rs12979860 non-CC (rate of SVR: 17.3%). Anticipated responders were those with HCV genotype 2-3, patients harboring HCV genotype 4 and IL28B CC, as well as those who simultaneously bore HCV genotype 1, HCV-RNA load <600,000IU/ml, and IL28B CC (rate of SVR 74.1%, 77.8%, and 64.4%, respectively). The area under the receiver operating characteristic curve of the model was 0.77 (0.733-0.814). CONCLUSIONS: The combined use of IL28B genotype, HCV genotype, and HCV-RNA load enables to easily identify patients with a high and very low likelihood of SVR. HCV therapy could be deferred in the latter patients, until more effective options are available, at least if they do not show advanced liver fibrosis.

N-protein presents early in blood, dried blood and saliva during asymptomatic and symptomatic SARS-CoV-2 infection.

The COVID-19 pandemic continues to have an unprecedented impact on societies and economies worldwide. There remains an ongoing need for high-performance SARS-CoV-2 tests which may be broadly deployed for infection monitoring. Here we report a highly sensitive single molecule array (Simoa) immunoassay in development for detection of SARS-CoV-2 nucleocapsid protein (N-protein) in venous and capillary blood and saliva. In all matrices in the studies conducted to date we observe >98% negative percent agreement and >90% positive percent agreement with molecular testing for days 1-7 in symptomatic, asymptomatic, and pre-symptomatic PCR+ individuals. N-protein load decreases as anti-SARS-CoV-2 spike-IgG increases, and N-protein levels correlate with RT-PCR Ct-values in saliva, and between matched saliva and capillary blood samples. This Simoa SARS-CoV-2 N-protein assay effectively detects SARS-CoV-2 infection via measurement of antigen levels in blood or saliva, using non-invasive, swab-independent collection methods, offering potential for at home and point of care sample collection.

Pegylated interferon-alpha for the treatment of sexually transmitted acute hepatitis C in HIV-infected individuals.

BACKGROUND: Sexually transmitted acute hepatitis C among HIV-positive homosexual men has been noted as an emerging epidemic. METHODS: Forty-seven patients with mainly sexually acquired, acute hepatitis C were enrolled in this prospective, multicentre trial, and 36 of these patients were treated within the acute phase of hepatitis C infection with pegylated interferon (peg-IFN) therapy. RESULTS: Early treatment resulted in sustained virological response in 61% of patients. Peg-IFN alone showed similar treatment response rates and lower incidence of anaemia compared with peg-IFN+ribavirin combination therapy. Higher treatment response rates were observed in patients treated over 48 weeks compared with 24 weeks. CONCLUSIONS: Treatment of hepatitis C in HIV-positive individuals in the acute phase of infection leads to high rates of sustained virological response. Optimal time and mode of therapy have yet to be defined.

Effect of the interleukin-6 C174G gene polymorphism on treatment of acute and chronic hepatitis C in human immunodeficiency virus coinfected patients.

UNLABELLED: Hepatitis C virus (HCV)/human immunodeficiency virus (HIV) coinfection poses a difficult therapeutic problem. Response to HCV-specific therapy is variable but might be influenced by host genetic factors, including polymorphisms of cytokine genes. Here, we studied whether interleukin-6 (IL-6) C174G gene polymorphism affects the response to antiviral treatment in HCV-infected HIV-positive subjects. We determined IL-6 genotypes in HIV-positive patients with acute (n = 52) and chronic (n = 60) hepatitis C treated with pegylated interferon-alpha. Two hundred ten HCV monoinfected, 197 HIV monoinfected, and 100 healthy individuals were studied as controls. Patients were classified into high and low producers according to IL-6 genotypes. Rates of sustained virological responses (SVRs) were compared between the IL-6 genotypes. Signal transducer and activator of transcription three phosphorylation was analyzed by Western blot in HCV core-transfected human hepatoma cell line (HUH7) cells. Distribution of IL-6 genotypes did not differ significantly between the study groups. SVR was achieved in 63% of HIV/HCV coinfected patients. Carriers of the IL-6 high producer (HP) genotype had significantly higher SVR rates than patients with an IL-6 low producer genotype (70.1% versus 52%; P < 0.002). This effect was seen in both HIV-positive patients with acute (74% versus 33%; P < 0.05) and chronic (66% versus 33%; P < 0.05) hepatitis C. Multivariate analysis confirmed IL-6 HP carriage as an independent positive predictor for SVR (Odd's ratio 6.1; P = 0.004). This effect corresponds to the in vitro observation that in HCV core-transfected HUH7 cells, IL-6 overcomes the HCV core-mediated inhibition of STAT3 activation. CONCLUSION: Response rates to HCV-specific treatment are higher in HCV/HIV-positive patients carrying the IL-6 HP genotype, which might be because of IL-6 mediated STAT3 activation.