Osteoradionecrosis incidence in pre-radiation teeth extractions: A prospective study

AIMS

To evaluate osteoradionecrosis (ORN) incidence in a cohort of patients undergoing tooth extraction (TE) before radiotherapy (RT) for head and neck cancers.

METHODS

The study protocol was approved by the Ethics Committee of Università Cattolica del Sacro Cuore (ID-2132) and registered at clinicaltrials.gov (ID: NCT04009161). TE was performed in case of signs of pericoronitis, periapical lesions, restorative impossibility, severe periodontitis. ORN was defined as exposed bone at an unhealed post-extraction socket in the absence of oncological recurrence. The RT plans were reviewed, and each post-extractive socket was contoured to calculate the received radiation dose.

RESULTS

In total, 156 patients with 610 TE were enrolled. The mean follow-up was 567 days. ORN was diagnosed in four patients (2.6% of patients and 0.7% of TE). Need for osteotomy and radiation dose at the extraction site were associated with ORN (OR for osteotomy: 21.9, 95% CI: 2.17-222.2, p = 0.009; OR for RT dose: 1.1, 95% CI: 1-1.15, p = 0.05).

CONCLUSIONS

TE appears to be a significant risk factor for ORN, particularly when osteotomy is required, and post-extraction sockets receive a high RT dosage. This study proposes a decision-making algorithm for TE and outlines a straightforward surgical protocol.

Long-term dynamics of natural killer cells in response to SARS-CoV-2 vaccination: Persistently enhanced activity postvaccination

Natural Killer (NK) cells play a significant role in the early defense against virus infections and cancer. Recent studies have demonstrated the involvement of NK cells in both the induction and effector phases of vaccine-induced immunity in various contexts. However, their role in shaping immune responses following SARS-CoV-2 vaccination remains poorly understood. To address this matter, we conducted a comprehensive analysis of NK cell phenotype and function in SARS-CoV-2 unexposed individuals who received the BNT162b2 vaccine. We employed a longitudinal study design and utilized a panel of 53 15-mer overlapping peptides covering the receptor binding domain (RBD) of the SARS-CoV-2 Spike protein to assess NK cell function at 0 and 20 days following the first vaccine, and 30 and 240 days following booster. Additionally, we evaluated the levels of total IgG anti-Spike antibodies and their potential neutralizing ability. Our findings revealed an increased NK cell activity upon re-exposure to RBD when combined with IL12 and IL18 several months after booster. Concurrently, we observed that the frequencies of NKG2A + NK cells declined over the course of the follow-up period, while NKG2C increased only in CMV positive subjects. The finding that NK cell functions are inducible 9 months after vaccination upon re-exposure to RBD and cytokines, sheds light on the role of NK cells in contributing to SARS-CoV-2 vaccine-induced immune protection and pave the way to further studies in the field.

Hepatitis C Virus and the Host: A Mutual Endurance Leaving Indelible Scars in the Host's Immunity

Hepatitis C virus (HCV) has spread worldwide, and it is responsible for potentially severe chronic liver disease and primary liver cancer. Chronic infection remains for life if not spontaneously eliminated and viral persistence profoundly impairs the efficiency of the host's immunity. Attempts have been made to develop an effective vaccine, but efficacy trials have met with failure. The availability of highly efficacious direct-acting antivirals (DAA) has created hope for the progressive elimination of chronic HCV infections; however, this approach requires a monumental global effort. HCV elicits a prompt innate immune response in the host, characterized by a robust production of interferon-α (IFN-α), although interference in IFN-α signaling by HCV proteins may curb this effect. The late appearance of largely ineffective neutralizing antibodies and the progressive exhaustion of T cells, particularly CD8 T cells, result in the inability to eradicate the virus in most infected patients. Moreover, an HCV cure resulting from DAA treatment does not completely restore the normal immunologic homeostasis. Here, we discuss the main immunological features of immune responses to HCV and the epigenetic scars that chronic viral persistence leaves behind.

The immunogenicity and the safety of the adjuvanted glycoprotein E (gE)-based recombinant vaccine against herpes zoster (RZV) in cancer patients during immunotherapy

Herpes zoster (HZ) is caused by the reactivation of latent varicella zoster virus (VZV). Severe immunocompromising conditions, such as solid tumors, have been largely associated with an increased risk for HZ due to waning VZV-specific cellular immunity. With the approval of the adjuvanted glycoprotein E (gE)-based recombinant vaccine (RZV; Shingrix™, GSK) also in immunocompromised subjects, HZ is considered a vaccine-preventable disease changing perspectives in immunocompromised subjects. To date, no clinical trial has evaluated the immunogenicity in the patients with cancer undergoing immunotherapy. In this study, we describe the humoral and cell-mediated immune responses in 38 cancer patients treated with immune checkpoint inhibitors (ICIs) and receiving RZV. We used samples collected at baseline (T0), 3 weeks (T2), and 6 months (T3) after the complete RV vaccination schedule. Our data showed that a significant proportion (40,5%) of RZV recipients mounted a stronger humoral and cell-mediated immune response at 3 weeks (T2) after complete RZV vaccination schedule. Interestingly, both humoral and cell-mediated immune responses were mostly stable over 6 months (T3). Interestingly, the overall IFNγ-producing lymphocytes was mainly associated with CD4 T cell response (p = .0012). In conclusion, data from our pilot study suggest a strong and long-lasting immunogenicity of RZV in ICI-treated patients. Prospective analyses at 1 year after vaccination will be performed in order to evaluate the long-term persistence of humoral and cell-mediated response against RZV.

Humoral and Cellular Immune Response Elicited by the BNT162b2 COVID-19 Vaccine Booster in Elderly

Although the safety and efficacy of COVID-19 vaccines in older people are critical to their success, little is known about their immunogenicity among elderly residents of long-term care facilities (LTCFs). A single-center prospective cohort study was conducted: a total IgG antibody titer, neutralizing antibodies against Wild-type, Delta Plus, and Omicron BA.2 variants and T cell response, were measured eight months after the second dose of BNT162b2 vaccine (T0) and at least 15 days after the booster (T1). Forty-nine LTCF residents, with a median age of 84.8 ± 10.6 years, were enrolled. Previous COVID-19 infection was documented in 42.9% of the subjects one year before T0. At T1, the IgG titers increased up to 10-fold. This ratio was lower in the subjects with previous COVID-19 infection. At T1, IgG levels were similar in both groups. The neutralizing activity against Omicron BA.2 was significantly lower (65%) than that measured against Wild-type and Delta Plus (90%). A significant increase of T cell-specific immune response was observed after the booster. Frailty, older age, sex, cognitive impairment, and comorbidities did not affect antibody titers or T cell response. In the elderly sample analyzed, the BNT162b2 mRNA COVID-19 vaccine produced immunogenicity regardless of frailty.

Ceramide present in cholangiocarcinoma-derived extracellular vesicle induces a pro-inflammatory state in monocytes

Cholangiocarcinoma (CCA) is a rare cancer characterized by a global increasing incidence. Extracellular vesicles (EV) contribute to many of the hallmarks of cancer through transfer of their cargo molecules. The sphingolipid (SPL) profile of intrahepatic CCA (iCCA)-derived EVs was characterized by liquid chromatography-tandem mass spectrometry analysis. The effect of iCCA-derived EVs as mediators of inflammation was assessed on monocytes by flow cytometry. iCCA-derived EVs showed downregulation of all SPL species. Of note, poorly-differentiated iCCA-derived EVs showed a higher ceramide and dihydroceramide content compared with moderately-differentiated iCCA-derived EVs. Of note, higher dihydroceramide content was associated with vascular invasion. Cancer-derived EVs induced the release of pro-inflammatory cytokines in monocytes. Inhibition of synthesis of ceramide with Myriocin, a specific inhibitor of the serine palmitoyl transferase, reduced the pro-inflammatory activity of iCCA-derived EVs, demonstrating a role for ceramide as mediator of inflammation in iCCA. In conclusion, iCCA-derived EVs may promote iCCA progression by exporting the excess of pro-apoptotic and pro-inflammatory ceramides.

Impaired intratumoral natural killer cell function in head and neck carcinoma

Natural killer (NK) cells are emerging as unique players in the immune response against cancer; however, only limited data are available on tumor infiltrating NK cells in head and neck squamous cell carcinoma (HNSCC), one of the most common cancer. Occurrence of HNSCC is closely related to the immune microenvironment, and immunotherapy is increasingly being applied to this setting. However, the limited success of this type of treatment in this tumor calls for further investigation in the field.

Surgical HNSSC specimens of 32 consecutive patients were mechanically and enzymatically dissociated. Tumor cells were separated from infiltrating cells by short centrifugation and infiltrating NK cells were phenotypically and functionally characterized by multiple antibody staining and flow cytometry. Tumor infiltrating NK cells in HNSCC showed a peculiar phenotype predominantly characterized by increased NKG2A and reduced Siglec-7, NKG2D, NKp30 and CD16 expression. This phenotype was associated with a decreased ability to perform antibody-dependent cellular cytotoxicity (ADCC). However, NK, CD4 and CD8 shared an increment of glucocorticoid-induced tumor necrosis factor-related (GITR) costimulatory receptor which could be exploited for immunotherapy with agonistic anti-GITR antibodies combined with checkpoint inhibitors.

Right ventricular free wall longitudinal strain (RVFWSL) a new outcome predictor in patients candiate for TAVI

Background

Right ventricular (RV) systolic dysfunction is considered an outcome predictor in various cardiovascular diseases. RV dysfunction, assessed by RV free wall longitudinal strain (RVFWSL) in patients candidate for trans-catheter aortic valve implantation (TAVI), has not been extensively explored as an outcome predictor.

Purpose

Evaluate the prognostic value of pre intervention RVFWSL in patients undergoing TAVI.

Methods

Retrospective analysis of 100 patients who underwent transfemoral TAVI in our hospital from 2015 to 2019, with at least a pre and post-TAVI echocardiography. Clinical and echocardiographic data before and after TAVI and follow-up data were collected. We considered the value of [23.3]% the cut-off of normality for RVFWSL. The primary end-point was a composite of death from any cause and hospitalization for heart failure.

Results

The median age of the patients was 81 years (79–83) with a functional status NYHA II–III (81%) before the intervention. EF was preserved in most of the patients (median 56%, 55–58), while Right ventricle dysfunction assessed with RVFWLS was reduced in half of the patients at baseline. At a median follow-up of 1023 days (630–1387), the univariate analysis demonstrated a predictive value for a reduced RVFWSL (<[23.3]%, P=0.015) and EF<50% (P=0.014) before TAVI. Cox regression analysis found that pre-TAVI reduced RVFWSL (HR 2.875, 95% CI: 1.113–7.425; P=0.03) and EF <50% (HR 2.511, 95% CI: 1.07–5.892; P=0.03) were independently associated with composite end-point of the study. Moreover, a reduced EF associated with RVFWSL <[23.3]% showed an incremental value in predicting the outcome (P=0.021).

Conclusions

Among patients with severe aortic stenosis undergoing TAVI, a reduced pre-implant RVFWSL is able to predict long-term outcome.

Funding Acknowledgement

Type of funding sources: None.

Defective DNAM-1 Dependent Cytotoxicity in Hepatocellular Carcinoma-Infiltrating NK Cells

Simple Summary

Hepatocellular carcinoma (HCC) is the most common form of primary liver cancer and the fourth leading cause of cancer-related deaths worldwide. Although therapeutic options have improved in the last few years, mortality remains disturbingly high. The key role of innate immunity, particularly of natural killer (NK) cells, in tumor surveillance and response is well established. The anti-tumor NK cell activity is modulated by interactions between NK cells activating or inhibiting receptors and their ligands, expressed or released by tumor cells. Alterations in these networks lead to inadequate NK cell responses and a lack of cancer control. In our study, we focus on NK cells activating receptor DNAM-1 and its ligand CD155, expressed in HCC cells. We provide evidence of impaired NK cytotoxic function as a result of altered receptor/ligand axis. We conclude that this may represent a tumor escape mechanism and a possible target for new immunotherapeutic approaches to HCC treatment.

Abstract

Background: Natural killer (NK) cells play a key role in immune surveillance and response to tumors, their function regulated by NK cell receptors and their ligands. The DNAM-1 activating receptor recognizes the CD155 molecule expressed in several tumor cells, such as hepatocellular carcinoma (HCC). This study aims to investigate the role of the DNAM-1/CD155 axis in mediating the NK cell response in patients with HCC. Methods: Soluble CD155 was measured by ELISA. CD155 expression was sought in HCC cells by immunohistochemistry, qPCR, and flow cytometry. DNAM-1 modulation in NK cells was evaluated in transwell experiments and by a siRNA-mediated knockdown. NK cell functions were examined by direct DNAM-1 triggering. Results: sCD155 was increased in sera from HCC patients and correlated with the parameters of an advanced disease. The expression of CD155 in HCC showed a positive trend toward better overall survival. DNAM-1 downmodulation was induced by CD155-expressing HCC cells, in agreement with lower DNAM-1 expressions in tumor-infiltrating NK (NK-TIL) cells. DNAM-1-mediated cytotoxicity was defective both in circulating NK cells and in NK-TIL of HCC patients. Conclusions: We provide evidence of alterations in the DNAM-1/CD155 axis in HCC, suggesting a possible mechanism of tumor resistance to innate immune surveillance.

Early and Polyantigenic CD4 T Cell Responses Correlate with Mild Disease in Acute COVID-19 Donors

We assessed SARS-CoV-2-specific CD4+ and CD8+ T cell responses in samples from 89 acute COVID-19 patients, utilizing blood samples collected during the first wave of COVID-19 in Italy. The goal of the study was to examine correlations between SARS-CoV-2-specific T cell responses in the early phase comparing mild, moderate, or severe COVID-19 disease outcomes. T cell responses to the spike (S) and non-S proteins were measured in a combined activation-induced marker (AIM) and intracellular cytokine staining (ICS) assay. Early CD4+ T cell responses to SARS-CoV-2 S correlated with milder disease by both AIM and IFNγ ICS readouts. The correlation of S-specific CD4+ T cell responses with milder disease severity was most striking within the first two weeks of symptom onset compared to later time points. Furthermore, donors with milder disease were associated with polyantigenic CD4+ T cell responses that recognized more prominently non-S proteins in addition to S, while severe acute COVID-19 was characterized by lower magnitudes of CD4+ T cell responses and a narrower repertoire. In conclusion, this study highlights that both the magnitude and breadth of early SARS-CoV-2-specific CD4+ T cell responses correlated with milder disease outcomes in acute COVID-19 patients.

P129 IMPACT OF THE ATHEROSCLEROTIC PABULUM ON IN–HOSPITAL MORTALI–TY FOR SARS–COV–2 INFECTION. IS CALCIUM SCORE ABLE TO IDENTIFY AT RISK PATIENTS?

Background

Although the primary cause of death in COVID–19 infection is respiratory failure, there are evidences that cardiac manifestations may contribute to overall mortality and can even be the primary cause of death. More importantly, it is recognised that COVID–19 is associated with a high incidence of thrombotic complications.

Aim of the Study

evaluate if CAC score was useful to predict in–hospital mortality and complications in patients with COVID infection

Methods

Two–hundred–eighty–four patients with proven SARS–CoV2 infection who had a non–contrast Chest CT at our facility were retrospective analysed for coronary artery calcium (CAC) score. Primary endpoint was in–h mortality. Secondary end–points were need for mechanical ventilation and Intensive Care Unit admission. Clinical and radiological data were retrieved.

Results

Patients with coronary calcium had higher inflammatory burden at admission (D–dimer, CRP, Procalcitonin) and higher high–sensitive Troponin I (HScTnI) at admission and at peak. While there was no association with presence of consolidation and ground glass opacities, patients with coronary calcium had higher incidence of bilateral infiltration and higher in–hospital mortality. The main finding of our research is that CAC alone does not completely identify all the population at risk of events in the setting of COVID 19 patients. Peak HScTnI was associated with higher mortality, intensive care unit admission and mechanical ventilation in both univariable at multivariable analysis.

Conclusions

Together with the presence of higher inflammation burden CAC may be a useful marker in identifying patients at risk of cardiovascular complications and in hospital mortality.

P104 FEASIBILITY AND ROLE OF ECHOCONTRAST EVALUATION IN PATIENTS WITH LVAD

Background

Advanced heart failure is a clinical syndrome characterized by persistent or progressive symptoms of heart failure despite optimal medical therapy. Left ventricular assist device (LVAD) brings survival benefits and improvement in quality of life, compared with conventional medical treatments. Development of Right ventricle failure in patients with LVAD has a direct effect on mortality and hospitalization.

Purpose

evaluation of clinical safety and feasibility of echocontrast in patients implanted with 3 different types of LVAD; improvement in the visualization of heart structures; intra and inter–operator agreement of RV assesement with and without contrast. Methods 43 patients were implanted with LVAD, 7 patients (16%) with Jarvik 2000, 31 (72%) with HeartMAte 3, 5 (12%) with (HeartWAre HVAD). Nine patients (21%) had contraindication or refused contrast. In 3 (7%) patients was technically challenging to obtain apical images at all levels. Two (5%) patients lost their follow–up. Our final population was of 29 (67%) patients (mean age 65±7 y; 100% Male). We assessed the reproducibility of these measurements between two different expert blind operators

Results

Total 329 (64%) of 516 RV wall segments were available for qualitative analysis without contrast vs 451 (87%) with contrast (p < 0.001) with a significant improvement of the evaluability of regional contractility (especially due to the better evaluation of medial and apical segments of lateral and anterior walls) and FAC (41% vs 90%, p < 0.001). Evaluation of TAPSE, TR and sPAP was similar with and without contrast (p=NS). All the RV parameters showed little inter–operator variability when measured with contrast. TAPSE, FAC, and RWMA showed an excellent reproducibility (ICC >0.86) while it was good for 2D–baseline derived parameters (ICC = 0.74) showing improvement of inter operator reproducibility in the evaluation of regional contractility in the contrast echocardiography modality.

Conclusion

EC is safe with all the types of LVAD examined. Accurate and reproducible visualization of RV is imperative for reliability of information, a routine use of EC could play a pivotal role in interpreting RV features. EC improves RV morphologic and functional judgment allowing greater accuracy and precision in the assessment of both global and regional RV functions. This finding may have important clinical improvement, especially in the future for analysis focused in RV prognostic role in LVAD patients.

C38 RIGHT VENTRICULAR FREE WALL LONGITUDINAL STRAIN (RVFWSL) A NEW OUTCOME PREDICTOR IN PATIENTS CANDIDATE FOR TAVI

Background

Right ventricular (RV) systolic dysfunction is considered an outcome predictor in various cardiovascular diseases. RV dysfunction, assessed by RV free wall longitudinal strain (RVFWSL) in patients candidate for trans–catheter aortic valve implantation (TAVI), has not been extensively explored as an outcome predictor.

Purpose

Evaluate the prognostic value of pre intervention RVFWSL in patients undergoing TAVI. Methods: retrospective analysis of 100 patients who underwent transfemoral TAVI in our hospital from 2015 to 2019, with at least a pre and post–TAVI echocardiography. Clinical and echocardiographic data before and after TAVI and follow–up data were collected. We considered the value of [23.3]% the cut–off of normality for RVFWSL. The primary end–point was a composite of death from any cause and hospitalization for heart failure.

Results

The median age of the patients was 81 years (79–83) with a functional status NYHA II–III (81%) before the intervention. EF was preserved in most of the patients (median 56%, 55–58), while Right ventricle dysfunction assessed with RVFWLS was reduced in half of the patients at baseline. At a median follow–up of 1023 days (630–1387), the univariate analysis demonstrated a predictive value for a reduced RVFWSL ( < [23.3]%, P = 0.015) and EF < 50% (P = 0.014) before TAVI. Cox regression analysis found that pre–TAVI reduced RVFWSL (HR 2.875, I.C. 95% 1.113–7.425; P = 0.03) and EF < 50% (HR 2.511, I.C. 95% 1.07–5.892; P = 0.03) were independently associated with composite end–point of the study. Moreover, a reduced EF associated with RVFWSL < [23.3]% showed an incremental value in predicting the outcome (P = 0.021).

Conclusions

Among patients with severe aortic stenosis undergoing TAVI, a reduced pre–implant RVFWSL is able to predict long–term outcome.

C47 CORO–CT PLAQUE ANALYSIS IN ASSESSMENT OF CARDIOVASCULAR RISK

Background

Computed tomographic (CT) coronary angiography represents a non–invasive approach to assess plaque characteristics that provides information to change treatment of coronary artery disease (CAD) and to asses risk stratification.

Purpose

Analyze the differences in plaque composition between patients with different plaque features: soft unstable plaques, hard stable plaques and no plaques; identify whether there is a relationship between the plaque density and the pericoronary fat attenuation index (pFAI). Materials and methods: 372 patients retrospectively analyzed who underwent CTCA for exclusion of CAD. They were divided into three groups: 37 (10%) patients with high attenuated plaques (> 60HU), 137 (37%)with low attenuated plaques (<29 HU and a volume of at least 15 mm3 and/or 30–59 HU with a volume greater than 52 mm3) and 198 (53%) patients without significant CAD. For each patients we collected clinical, radiological and follow–up data.

Results and Discussion

Low–attenuated plaques are significantly associated with older age, male sex, dyslipidemia and diabetes mellitus (p < 0.001). Higher values of pFAI were more present in patients with soft plaques than in those with stable plaques and without plaques (p = 0.005). It was also found that soft plaques were present in more CA segments compared to stable plaques. Overall volume of soft plaque appears greater than hard plaques and mainly localized in the anterior descendant coronary artery with higher stenosis values (p < 0.001). Presence of plaques with soft or high–risk features predisposes significantly and independently (p < 0.001) to a composite outcome (death, in–hospital admissions for percutaneous angioplasty or by–pass procedures) at the follow up.

Conclusions

Coronary plaque analysis showed a good correlation between high–risk plaques and pFAI, supporting the hypothesis that the presence of high–risk plaques can be correlated to inflammatory burden. Furthermore, the presence of high risk plaques predispose to death or hospitalization for coronary intervention.

MICA/B-targeted antibody promotes NK cell-driven tumor immunity in patients with intrahepatic cholangiocarcinoma

The major histocompatibility complex-class I chain related proteins A and B (MICA/B) is upregulated because of cellular stress and MICA/B shedding by cancer cells causes escape from NKG2D recognition favoring the emergence of cancers. Cholangiocarcinoma (CCA) is a relatively rare, though increasingly prevalent, primary liver cancer characterized by a late clinical presentation and a dismal prognosis. We explored the NKG2D-MICA/B axis in NK cells from 41 patients with intrahepatic cholangiocarcinoma (iCCA). The MICA/B-specific 7C6 mAb was used for ex vivo antibody-dependent cytotoxicity (ADCC) experiments using circulating, non tumor liver- and tumor-infiltrating NK cells against the HuCCT-1 cell line and patient-derived primary iCCA cells as targets. MICA/B were more expressed in iCCA than in non-tumoral tissue, MICA transcription being higher in moderately-differentiated compared with poorly-differentiated cancer. Serum MICA was elevated in iCCA patients in line with higher expression of ADAM10 and ADAM17 that are responsible for proteolytic release of MICA/B from tumor. Addition of 7C6 significantly boosted peripheral, liver- and tumor-infiltrating-NK cell degranulation and IFNγ production toward MICA/B-expressing established cell lines and autologous iCCA patient target cells. Our data show that anti-MICA/B drives NK cell anti-tumor activity, and provide preclinical evidence in support of 7C6 as a potential immunotherapeutic tool for iCCA.

Feasibility and role of echocontrast evaluation of patients with LVAD

Funding Acknowledgements

Type of funding sources: None.

Background

In patients with Advanced heart failure (AHF) long-term support with durable mechanical circulatory support (MCS) devices such as left ventricular assist device (LVAD) brings survival benefits and improvement in quality of life, compared with conventional medical treatments. Development of RVF in patients with LVAD has a direct effect on mortality and is associated with prolonged length of stay in intensive care unit and in-hospital stay and with poor quality of life. Purpose: the evaluation of clinical safety and feasibility of  echocontrast (EC) in patients implanted with 3 different types of LVAD (HeartWAre HVAD, Jarvik 2000, HeartMate 3); the assessment of the improvement in the visualization of heart structures; the intra and inter-operator agreement of RV measurements (FAC, TAPSE, sPAP, TR,  regional wall motion abnormalities) with and without contrast. Methods: Between 2014 and 2019, 43 patients were implanted with LVAD, in particular 7 (16%) patients were implanted with Jarvik 2000, 31 (72%) with HeartMAte 3, 5 (12%) pts with HeartWAre HVAD. Nine patients (21%) either had contraindication or refused contrast injection. In 3 (7%) patients, it was technically challenging to obtain apical images at all levels. Two (5%) patients lost their follow-up. Our final population was of 29 (67%) patients. We also assessed the reproducibility of these measurements between two different expert operators (blind analysis). Results:  We observed no allergic reaction to EC. Total 329 (64%) of 516 RV wall segments were available for qualitative analysis without contrast vs 451 (87%) with contrast (p < 0.001) with a significant improvement of the evaluability of regional contractility and FAC  (41% vs 90%, p < 0.001). Evaluation of TAPSE, TR and sPAP was similar with and without contrast (p = NS) All the RV parameters showed little inter-operator variability when measured with contrast. TAPSE, FAC, and RWMA showed an excellent reproducibility (ICC >0.86) while it was good for 2D-baseline derived parameters (ICC = 0.74) showing improvement of inter operator reproducibility in the evaluation of regional contractility in the contrast echocardiography modality. Conclusion: EC is safe with all the types of LVAD we examined. Accurate and reproducible visualization of RV is imperative for reliability of information, a routine use of EC could play a pivotal role in interpreting RV features.  EC improves RV morphologic and functional judgment; allowing greater accuracy and precision in the assessment of both global and regional RV functions. This finding may have important clinical improvement, especially in the future for analysis focused in RV prognostic role in LVAD patients

High Frequencies of Functional Virus-Specific CD4+ T Cells in SARS-CoV-2 Subjects With Olfactory and Taste Disorders

Olfactory and taste disorders (OTD) are commonly found as presenting symptoms of SARS-CoV-2 infection in patients with clinically mild COVID-19. Virus-specific T cells are thought to play an important role in the clearance of SARS-CoV-2; therefore the study of T cell specific immune responses in patients with mild symptoms may help to understand their possible role in protection from severe disease. We evaluated SARS-CoV-2-specific T cell responses to four different peptide megapools covering all SARS-CoV-2 proteins during the acute phase of the disease in 33 individuals with mild or no other symptom beside OTD and in 22 age-matched patients with severe infection. A control group of 15 outpatients with OTD and consistently negative nasopharyngeal SARS-CoV-2 RNA swabs and virus-specific IgG serology was included in the study. Increased frequencies of virus-specific CD4⁺ and CD8⁺ T cells were found in SARS-CoV-2 positive patients with OTD compared with those with severe COVID-19 and with SARS-CoV-2 negative OTD individuals. Moreover, enhanced CD4⁺ and CD8⁺ T-cell activation induced by SARS-CoV-2 peptides was associated with higher interferon (IFN)γ production. Increased frequencies of Spike (S1/S2)-specific CD4⁺ T cells showing enhanced IFNγ secretion and granzyme B content were associated with serum spike-specific IgG in the OTD group. In conclusion, patients with SARS-CoV-2 induced OTD develop highly functional virus-specific CD4⁺ and CD8⁺ T cells during the symptomatic phase of the disease, suggesting that robust and coordinated T-cell responses provide protection against extension of COVID-19 to the lower respiratory tract.

A new algorithm shows superior ability to discriminate liver fibrosis stages in chronic hepatitis C

Previous evidence suggests that sialic acid-binding Ig-like lectin 7 (Siglec-7) protein is significantly increased in patients with chronic hepatitis C virus (HCV) infection and directly correlates with clinical parameters of liver inflammation and fibrosis. The aim of this study was to determine the diagnostic value of Siglec-7 as a non-invasive tool to assess liver fibrosis in patients with chronic hepatitis C in a cross-sectional study. Serum levels of Siglec-7 were retrospectively tested in 1007 consecutive patients with chronic HCV infection recruited at three different European sites and data examined by the 'imperfect gold-standard' statistical analysis. Liver stiffness obtained by transient elastography (TE) was considered the standard reference. Liver fibrosis was staged according to published cut-offs of liver stiffness measurement by TE. Accuracy of detection of liver fibrosis stage was not increased by Siglec-7 alone. However, we developed a new index (SiGAP) including Siglec-7, γ-glutamyl transferase, age and platelet count which showed increased sensitivity and specificity in predicting fibrosis compared with APRI or FIB4 indices. The AUROC of SiGAP for the diagnosis of significant (≥F2) and advanced liver fibrosis (≥F3) showed significantly higher values than those of APRI and FIB-4. Siglec-7 may be useful as a complementary tool to assess liver fibrosis stage in patients with chronic hepatitis C when included in a specifically designed algorithm, which showed high level of accuracy in the detection of F2 and F3 fibrosis stage.

Unique immunological profile in patients with COVID-19

The relationship between severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and host immunity is poorly understood. We performed an extensive analysis of immune responses in 32 patients with severe COVID-19, some of whom succumbed. A control population of healthy subjects was included. Patients with COVID-19 had an altered distribution of peripheral blood lymphocytes, with an increased proportion of mature natural killer (NK) cells and low T-cell numbers. NK cells and CD8⁺ T cells overexpressed T-cell immunoglobulin and mucin domain-3 (TIM-3) and CD69. NK cell exhaustion was attested by increased frequencies of programmed cell death protein 1 (PD-1) positive cells and reduced frequencies of natural killer group 2 member D (NKG2D)-, DNAX accessory molecule-1 (DNAM-1)- and sialic acid-binding Ig-like lectin 7 (Siglec-7)-expressing NK cells, associated with a reduced ability to secrete interferon (IFN)γ. Patients with poor outcome showed a contraction of immature CD56^bright and an expansion of mature CD57⁺ FcεRIγ^neg adaptive NK cells compared to survivors. Increased serum levels of IL-6 were also more frequently identified in deceased patients compared to survivors. Of note, monocytes secreted abundant quantities of IL-6, IL-8, and IL-1β which persisted at lower levels several weeks after recovery with concomitant normalization of CD69, PD-1 and TIM-3 expression and restoration of CD8⁺ T cell numbers. A hyperactivated/exhausted immune response dominate in severe SARS-CoV-2 infection, probably driven by an uncontrolled secretion of inflammatory cytokines by monocytes. These findings unveil a unique immunological profile in COVID-19 patients that will help to design effective stage-specific treatments for this potentially deadly disease.

Adaptive Natural Killer Cell Functional Recovery in Hepatitis C Virus Cured Patients

BACKGROUND AND AIMS

Current evidence suggests that dysfunctional natural killer (NK) cell responses during hepatitis C virus (HCV) infection can be restored after viral eradication with direct acting antivirals (DAAs). However, the fate of the recently described adaptive NK cell population, endowed with increased ability to mediate antibody-dependent cell-mediated cytotoxicity (ADCC), during HCV infection is poorly defined, while no study has explored the effects of DAAs on this NK subset.

APPROACH AND RESULTS

We performed multicolor flow cytometry to investigate CD57⁺ FcεRIγ^neg adaptive and FcεRIγ^pos conventional NK cell phenotype and function before and after DAA treatment in 59 patients chronically infected with HCV, 39 with advanced liver fibrosis, and 20 with mild-moderate liver fibrosis. Moreover, bulk NK cell phenotype and function were analyzed after cytokine activation following contact with K562 target cells. The proportion of FcεRIγ^neg NK cells in patients with HCV was associated with increased HCV load at baseline, and it was significantly reduced after treatment. Patients with an advanced fibrosis stage displayed increased NK cell activation and exhaustion markers that normalized after therapy. Of note, adaptive NK cells from patients with HCV were characterized by increased programmed death receptor 1 expression and reduced ADCC activity at baseline. DAA treatment restored ADCC ability and reduced programmed death receptor 1 expression.

CONCLUSIONS

HCV profoundly affects the frequency, phenotype, and function of adaptive NK cells. DAA therapy restores a normal adaptive NK phenotype and enhances interferon-gamma production by this cell subset.

An Anti-MICA/B Antibody and IL-15 Rescue Altered NKG2D-Dependent NK Cell Responses in Hepatocellular Carcinoma

Natural killer (NK) cells play a pivotal role in cancer immune surveillance, and activating the receptor/ligand interaction may contribute to control the development and evolution of hepatocellular carcinoma (HCC). We investigated the role of the natural killer group 2 member D (NKG2D) activating receptor and its ligand, the major histocompatibility complex class I chain-related protein A and B (MICA/B) in patients with cirrhosis and HCC subjected to surgical resection, patients with cirrhosis and no HCC, and healthy donors (HD). The NKG2D-mediated function was determined in peripheral blood (PB), in tumor-infiltrating lymphocytes (NK-TIL), and in matched surrounding liver tissue (NK-LIL). A group of patients treated with sorafenib because of clinically advanced HCC was also studied. A humanized anti-MICA/B monoclonal antibody (mAb) was used in in vitro experiments to examine NK cell-mediated antibody-dependent cellular cytotoxicity. Serum concentrations of soluble MICA/B were evaluated by ELISA. IL-15 stimulation increased NKG2D-dependent activity which, however, remained dysfunctional in PB NK cells from HCC patients, in line with the reduced NKG2D expression on NK cells. NK-TIL showed a lower degranulation ability than NK-LIL, which was restored by IL-15 stimulation. Moreover, in vitro IL-15 stimulation enhanced degranulation and interferon-γ production by PB NK from patients at month one of treatment with sorafenib. Anti-MICA/B mAb associated with IL-15 was able to induce PB NK cytotoxicity for primary HCC cells in HD and patients with HCC, who also showed NK-TIL degranulation for autologous primary HCC cells. Our findings highlight the key role of the NKG2D-MICA/B axis in the regulation of NK cell responses in HCC and provide evidence in support of a potentially important role of anti-MICA/B mAb and IL-15 stimulation in HCC immunotherapy.

Predictors and outcome of contrast-induced acute kidney injury in older patients presenting with acute coronary syndrome

Background

The number of older patients presenting with acute coronary syndrome (ACS) is increasing. Routine percutaneous coronary intervention (PCI) is performed in order to improve outcome, but comorbidities associated with aging lead to a higher risk of treatment complications. Contrast-induced acute kidney injury (CI-AKI) represents potential harm in older and frail patients, but its impact on long term prognosis is not clear.

Purpose

To evaluate occurrence, predictors, and impact on long term outcome of CI-AKI in elderly patients presenting with ACS.

Methods

A prospective cohort of 392 older (≥70 years) ACS patients who underwent coronary angiography was enrolled. CI-AKI was defined as a serum creatinine increase at least ≥0.3 mg/dl in 48 h or at least ≥50% in 7 days. According to our department protocol, prophylactic hydration was performed to all patients with isotonic saline, given intravenously at a rate of 1 ml/kg body weight/h (0.5 ml/kg for patients with left ventricular ejection fraction <35%) for 12 h before (unless for emergent patients) and 24 h after PCI. Median follow up was 4 [3.0–4.1] years. Long term adverse outcomes include all-cause mortality and any hospitalization for cardiovascular causes (ACS, heart failure, arrhythmia, cerebrovascular accident).

Results

CI-AKI was observed in 72 patients (18.4%). Among patients who developed or not CI-AKI, no difference was found between clinical presentation (Non-ST segment elevation myocardial infarction (NSTEMI) vs. STEMI), left ventricular ejection fraction and multivessel coronary disease. Estimated glomerular filtration rate (odd ratio (OR) 3.59, confidence interval (CI) 1.79–7.20, p<0.001), contrast media volume (OR 1.006, CI 1.002–1.009, P=0.001), white blood cells (OR 1.18, CI 1.10–1.27, p<0.001), haemoglobin level (OR 0.81, CI 0.70–0.94, p=0.005) and chronic obstructive pulmonary disease (OR=5.37, CI 2.24–12.90, p<0.001) were independent predictors for CI-AKI. Patients with CI-AKI presented increased mortality rate both at 30-days (2.7% vs 0%, p=0.038) and at 4-years follow-up (all cause death 23.6 vs. 11.6%, p=0.013) (Figure 1: long term adverse outcomes). Multivariable Cox proportional hazards analysis revealed that diabetes (hazard ratio, HR 1.99, CI 1.33–2.97, p=0.001), atrial fibrillation (HR 2.49, CI 1.59–3.91, p<0.001), Killip class >1 (HR 2.20, CI 1.32–3.67, p=0.003) and haemoglobin level (HR 0.84, CI 0.76–0.92, p<0.001) were independently associated with adverse outcome, while CI-AKI represent a risk factor only at univariate analysis.

Conclusions

CI-AKI is a common complication among older adults undergoing coronary angiography for ACS. Patients who developed CI-AKI had worse outcome at long term follow-up. Actually, the occurrence of CI-AKI was not identified as an independent predictor for long-term adverse outcome, while it may represent a marker of severity of comorbidity and consequent poor prognosis, rather than a causal agent itself.

Figure 1. Kaplan-Maier Curve

Funding Acknowledgement

Type of funding source: None

Human Monoclonal Antibodies as Adjuvant Treatment of Chronic Hepatitis B Virus Infection

Despite the availability of an effective prophylactic vaccine leading to sterilizing immunity, hepatitis B virus (HBV) is responsible for chronic liver disease in more than 250 million individuals, potentially leading to cirrhosis and hepatocellular carcinoma. Antiviral drugs able to completely suppress virus replication are indeed available but they are, by and large, unable to eradicate the virus. Several alternative new treatment approaches are currently being developed but none have so far captured the interest of clinicians for possible clinical development. A constant feature of chronic HBV infection is T-cell exhaustion resulting from persistent exposure to high antigen concentrations as shown by the high expression of programmed cell death protein 1 (PD-1) by HBV-specific CD8 T cells. One way of tackling this problem is to develop HBV-specific neutralizing antibodies that would clear excess envelope proteins from the circulation, allowing for nucleos(t)ide analogs or other antiviral drugs now in preclinical and early clinical development to take advantage of a reconstituted adaptive immunity. Several fully human monoclonal antibodies (mAb) have been developed from HBV-vaccinated and subjects convalescent from acute hepatitis B that show different properties and specificities. It is envisaged that such neutralizing mAb may be used as adjuvant treatment to reduce viral protein load, thus rescuing adaptive immunity in an effort to optimize the effect of antiviral drugs.

Decreased interferon-γ production by NK cells from KIR haplotype B carriers in hepatitis C virus infection

BACKGROUND AND AIMS

Different population genetics studies showed that interactions between killer-cell immunoglobulin-like receptors (KIR) and HLA play a role in viral disease outcome, but functional correlates are missing. Building upon our previous work pointing to a regulatory role for KIR3DL1/DS1 in hepatitis C virus (HCV) infection, we analysed whether its expression may affect natural killer (NK) cell function in the presence or absence of its principal ligand HLA-Bw4 in KIR haplotype A and B carriers, which are characterized by a different representation of activating and inhibitory KIRs.

METHODS

We performed KIR and HLA class I genotypic analysis in 54 healthy donors (HD) and 50 HCV+ subjects and examined NK cell cytokine secretion and degranulation in the context of KIR3DL1-HLA-Bw4 match stratified by KIR haplotype.

RESULTS

KIR3DL1-HLA-Bw4 match induced functional NK cell modulation, reflected by reduced interferon (IFN)γ production in haplotype B HCV+ patients compared to HD. This functional impairment could be ascribed to the KIR3DS1 negative HCV-infected patient population, whose NK cells also showed a significantly decreased proportion of KIR3DL1. Haplotype A HCV-infected patients showed increased NK cell degranulation compared with HD in the absence of KIR-HLA-Bw4 match and this activity was associated with increased phosphorylation of signal transducer and activator of transcription (STAT) 1.

CONCLUSIONS

Our data show that NK cells from HCV+ patients have an unbalanced ability to produce IFNγ and to kill target cells in haplotype A and B carriers, suggesting the existence of complex functional differences governed by KIR-HLA interaction, particularly on KIR3DL1 expressing NK cells.

Speckle Tracking Echocardiography in Non-ST-Segment Elevation Acute Coronary Syndromes

Non-ST-segment elevation acute coronary syndromes (NSTE-ACSs) are a group of clinical conditions characterized by acute myocardial ischemia. Conventional echocardiography is generally used to evaluate cardiac function using wall motion analysis and left ventricular ejection fraction but may be insufficient to explore all the complex features of NSTE-ACSs, which may vary substantially from patient to patient in terms of severity of ischemia and extent of involved myocardium. In the last years, speckle tracking echocardiography (STE) has become a widely available technique for the non-invasive assessment of cardiac function and has been repeatedly applied in the setting of NSTE-ACSs. In this review we summarize current evidence about the use of STE in patients with NSTE-ACSs, trying to underline advantages and limitations in comparison with conventional echocardiography for: diagnosis of NSTE-ACS, differential diagnosis, identification of high-risk patients, and prediction of outcome.

Deficient Natural Killer Cell NKp30-Mediated Function and Altered NCR3 Splice Variants in Hepatocellular Carcinoma

The activating natural cytotoxicity receptor NKp30 is critical for natural killer (NK) cell function and tumor immune surveillance. The natural cytotoxicity receptor-3 (NCR3) gene is transcribed into several splice variants whose physiological relevance is still incompletely understood. In this study, we investigated the role of NKp30 and its major ligand B7 homolog 6 (B7-H6) in patients with hepatocellular carcinoma (HCC). Peripheral blood NK cell phenotype was skewed toward a defective/exhausted immune profile with decreased frequencies of cells expressing NKp30 and natural killer group 2, member D and an increased proportion of cells expressing T-cell immunoglobulin and mucin-domain containing-3. Moreover, NKp30-positive NK cells had a reduced expression of NCR3 immunostimulatory splice variants and an increased expression of the inhibitory variant in patients with advanced tumor, resulting in deficient NKp30-mediated functionality. Tumor-infiltrating lymphocytes showed a prevalent inhibitory NKp30 isoform profile, consistent with decreased NKp30-mediated function. Of note, there were significant differences in the cytokine milieu between the neoplastic and the surrounding non-neoplastic tissue, which may have further influenced NKp30 function. Exposure of NK cells to B7-H6-expressing HCC cells significantly down-modulated NKp30, that was prevented by small interfering RNA-mediated knockdown, suggesting a role for this ligand in inhibiting NKp30-mediated responses. Interestingly, B7-H6 expression was reduced in HCC tissue and simultaneously augmented as a soluble form in HCC patients, particularly those with advanced staging or larger nodule size. Conclusion: These findings provide evidence in support of a role of NKp30 and its major ligand in HCC development and evolution.

Altered natural killer cell cytokine profile in type 2 autoimmune hepatitis

Type 2 autoimmune hepatitis (AIH-2) is a rare disease presenting in early childhood. The immunopathogenetic mechanisms are poorly characterized, although a defect of regulatory T cells (Treg) has been shown. There is virtually no information on innate immune responses and natural killer (NK) cells in particular. We have performed an extended immunophenotypic and functional analysis of NK cells in children with AIH-2. We show that NK cell frequency is reduced in this setting and that the balance between NK activating and inhibitory receptors is skewed toward activation. More importantly, NK cells display an altered cytokine pattern characterized by increased IFNγ and reduced IL2 production which could contribute to impaired Treg function. Exposure of mononuclear cells to IL2 resulted in normalization of NK IFNγ production. Thus, our findings support treatment of AIH-2 with low-dose IL2, which would result in normalization of NK cell function and expansion of the Treg cell subset.

Lack of Siglec-7 expression identifies a dysfunctional natural killer cell subset associated with liver inflammation and fibrosis in chronic HCV infection

OBJECTIVE

Sialic-acid-binding immunoglobulin-like lectin-7 (Siglec-7) is a natural killer (NK) cell inhibitory receptor associated with NK phenotypic and functional abnormalities in HIV-1 infection. We investigated the significance of NK-expressed and serum soluble Siglec-7 in relation to NK functional ability and parameters of liver necroinflammation and fibrosis in chronic HCV infection.

DESIGN

NK-expressed and serum Siglec-7 were evaluated in 130 and 166 HCV-infected individuals by flow cytometry and ELISA, respectively. NK cell degranulation and cytokine secretion were determined by flow cytometry. 65 patients with chronic HBV infection, 84 with chronic biliary disorders and 168 healthy donors served as controls.

RESULTS

Expression of Siglec-7 was significantly decreased on NK cells from HCV-infected and HBV-infected patients and, conversely, serum Siglec-7 was significantly increased in these patients compared with controls. The frequency of Siglec-7pos NK cells was significantly higher at baseline in sustained virological responders to pegylated interferon-α/ribavirin treatment than in non-responders. Activating receptor expression was significantly higher in Siglec-7pos NK cells and was associated with increased degranulation and cytokine secretion compared with Siglec-7^neg cells. In chronic HCV infection, there was an inverse correlation between Siglec-7 expression and serum aminotransferases, γ-glutamyl transpeptidase, liver stiffness, aspartate aminotransferase to platelet ratio index and fibrosis-4 scores, and a positive correlation between serum Siglec-7 and the same clinical parameters, including histological staging.

CONCLUSIONS

These findings identify Siglec-7^neg NK cells as a dysfunctional subpopulation associated with severe liver disease in chronic HCV infection.

Hepatitis C virus inhibits CD4 T cell function via binding to Toll-like receptor 7

Toll-like receptor 7 (TLR7) is a ssRNA receptor that activates dendritic cells and macrophages upon ssRNA binding; however, little is known of its role in CD4⁺ T cells. We show here that hepatitis C virus (HCV) induces a dose dependent inhibition of cytokine production and expression of activation markers in CD4 T cells, which were restored by a TLR7-specific antagonist. These findings indicate that HCV induces CD4 T cell impairment via TLR7 which may contribute to failure of virus eradication, casting doubts on the use of TLR7 agonists to boost innate immunity in chronic RNA virus infections.

NKp30 isoforms in patients with chronic hepatitis C virus infection

Natural killer (NK) cells play an important role in virus infection, their action being regulated by several activating and inhibitory receptors. The NKp30 activating receptor and its isoforms have recently emerged as important determinants of efficient NK cell responses. We determined the relative proportions of NKp30 isoforms in patients with chronic hepatitis C virus (HCV) infection and healthy donors (HD). NK cell function (degranulation and cytokine production) and correlations with clinical parameters were assessed following unsupervised hierarchical clustering of patients according to isoform expression. NKp30 receptor expression on NK cells and all isoforms were reduced in HCV-infected patients. Patients were clustered into two groups: the HCV-1 group had similar isoform expression to the HD group, whereas the HCV-2 group had lower expression. The latter showed a better functional activity, and a higher proportion of the activating a isoform and of the NKp30 isoform a/c ratio compared with the HCV-1 cluster. There was a positive correlation between the activating a isoform and liver stiffness and an inverse relationship between the immunosuppressive c isoform and the fibrosis 4 score, suggesting a potentially important role of NKp30 isoforms in influencing liver damage and ensuing fibrosis.

Skewed B cells in chronic hepatitis C virus infection maintain their ability to respond to virus-induced activation

Chronic hepatitis C virus (HCV) infection is characterized by persistent B-cell activation, with enhanced differentiation and reduced proliferative ability. To assess the possible role of HCV in altering B-cell subset distribution, we examined ex vivo frequencies and B-cell inhibitory receptor expression in 37 chronic HCV-infected patients and 25 healthy donors (HD). In addition, we determined whether short-term exposure to culture-derived HCV (HCVcc) resulted in B-cell subset skewing and/or activation. There was a statistically significant increase in the frequencies of immature transitional, activated memory and tissue-like memory (TLM) B cells in HCV-infected patients compared with HD. We also found that the frequency of memory B cells correlated with serum HCV RNA levels. The proportion of B cells expressing the marker of exhaustion Fc receptor-like 4 (FcRL4) was generally low even though significantly higher in the patients' memory B-cell compartment compared with HD, and a positive correlation was found between the frequencies of the patients' TLM FcRL4+ B cells and serum alanine aminotransferase and histological activity index at liver biopsy. Exposure to cell-free HCVcc in vitro did not result in B-cell skewing but induced significant activation of naïve, TLM and resting memory B cells in HCV-infected patients but not in HD, in whom cell-associated virus was an absolute requirement for activation of memory B cells. These findings provide corroborative evidence in favour of significant B-cell subset skewing in chronic HCV infection and in addition show that expression of exhaustion markers in selected B-cell subsets does not impair virus-induced B-cell activation.

Environmental pollution due to cadmium: measure of semen quality as a marker of exposure and correlation with reproductive potential

PURPOSE

Contradictory reports exist in the literature regarding an association of cadmium with parameters of semen quality. The aim of the study was to assess cadmium levels in both blood and seminal plasma and to analyze the relationships between cadmium concentrations and lifestyle and semen parameters.

MATERIAL AND METHODS

Fifty healthy male volunteers were recruited to provide semen and blood samples. Each patient completed an extensive questionnaire regarding his occupation, residence, social status, diet, water source, smoking habits, and medical and surgical history. Semen analysis was carried out according to WHO guidelines. Detection of cadmium in both semen and blood samples was carried out by means of atomic absorption spectrophotometer.

RESULTS

Mean concentrations of cadmium were 8.18 ± 1.6 ng/ml in blood samples and 2.56 ± 0.9 ng/ml in semen samples. Cadmium blood levels were significantly higher in men from industrialized areas and in current smokers, but were not correlated with semen levels. A significant positive correlation was found between cadmium blood levels, number of immotile spermatozoa, and teratozoospermia index (TZI). Significant inverse relationships between cadmium blood concentration and type-a and type a + b motility were found.

CONCLUSIONS

The present data show a significant correlation between blood cadmium concentrations, cigarette smoking, occupational exposure, and parameters of semen quality. Such a reduction in spermiogenetic function could be an early marker of a toxic effect by cadmium pollution.

Sialic acid-binding Ig-like lectin-7 interacts with HIV-1 gp120 and facilitates infection of CD4pos T cells and macrophages

Background

Sialic acid-binding Ig-like lectin-7 (Siglec-7) expression is strongly reduced on natural killer (NK) cells from HIV-1 infected viremic patients. To investigate the mechanism(s) underlying this phenomenon, we hypothesized that Siglec-7 could contribute to the infection of CD4^pos target cells following its interaction with HIV-1 envelope (Env) glycoprotein 120 (gp120).

Results

The ability of Siglec-7 to bind gp120 Env in a sialic acid-dependent manner facilitates the infection of both T cells and monocyte-derived macrophages (MDMs). Indeed, pre-incubation of HIV-1 with soluble Siglec-7 (sSiglec-7) increases the infection rate of CD4^pos T cells, which do not constitutively express Siglec-7. Conversely, selective blockade of Siglec-7 markedly reduces the degree of HIV-1 infection in Siglec-7^pos MDMs. Finally, the sSiglec-7 amount is increased in the serum of AIDS patients with high levels of HIV-1 viremia and inversely correlates with CD4^pos T cell counts.

Conclusions

Our results show that Siglec-7 binds HIV-1 and contributes to enhance the susceptibility to infection of CD4^pos T cells and MDMs. This phenomenon plays a role in HIV-1 pathogenesis and in disease progression, as suggested by the inverse correlation between high serum level of sSiglec-7 and the low CD4^pos T cell count observed in AIDS patients in the presence of chronic viral replication.

Natural killer cell dynamic profile is associated with treatment outcome in patients with chronic HCV infection

BACKGROUND & AIMS

A substantial proportion of patients with chronic hepatitis C virus infection treated with pegylated interferon α/ribavirin fail to achieve sustained virological response (SVR). Since growing evidence suggests that innate immunity may influence treatment responses, we examined natural killer (NK) cell phenotypic and functional changes during standard antiviral therapy.

METHODS

Expression of several NK-cell regulatory molecules was evaluated by flow cytometry in 37 consecutive patients with chronic HCV infection at baseline and at different time points during and after discontinuation of treatment. Cytokine production was evaluated by intracellular staining. Cytolytic potential was assessed as degranulation and as antibody-dependent cytotoxicity.

RESULTS

Baseline frequencies of CD56(dim) NK cells and perforin content were significantly higher, whereas CD16 expression was lower in SVR vs. non-responder subjects. Analysis by linear regression for repeated measures during the first 12 weeks showed significantly increased frequencies of activated (CD69(+)) NK cells in rapid virological responders (RVR) and identified a typical NK cell profile associated with SVR, featuring higher NK perforin content, lower CD16 expression, and higher proportion of CD56(dim)/CD16(-) cells. Moreover, SVR patients displayed higher natural and antibody-dependent NK cell cytotoxicity. IL28B rs12979860 CC homozygosis was significantly associated with SVR, independently of NK-cell phenotype and function.

CONCLUSIONS

Different NK-cell phenotypic and functional features, in patients with chronic hepatitis C treated with standard therapy, were observed between non-responder vs. SVR patients, suggesting a potential role of NK cells in the response to treatment.

Natural killer cell functional dichotomy: a feature of chronic viral hepatitis?

Natural killer (NK) cells are involved in innate immune responses to viral infections either via direct cytotoxicity which destroys virus-infected cells or production of immunoregulatory cytokines which modulate adaptive immunity and directly inhibit virus replication. These functions are mediated by different NK subpopulations, with cytotoxicity being generally performed by CD56(dim) NK cells, whereas CD56(bright) NK cells are mainly involved in cytokine secretion. NK functional defects are usually combined so that impaired degranulation is often associated with deficient cytokine production. Innate immunity is thought to be relevant in the control of hepatitis virus infections such as hepatitis B virus (HBV) and hepatitis C virus (HCV), and recent findings reproducibly indicate that NK cells in chronic viral hepatitis are characterized by a functional dichotomy, featuring a conserved or enhanced cytotoxicity and a reduced production of interferon (IFN)-γ and tumor necrosis factor-α. In chronic HCV infection this appears to be caused by altered IFN-α signaling resulting from increased signal transducer and activator of transcription 1 (STAT1) phosphorylation, which polarizes NK cells toward cytotoxicity, and a concomitantly reduced IFN-α induced STAT4 phosphorylation yielding reduced IFN-γ mRNA levels. These previously unappreciated findings are compatible on the one hand with the inability to clear HCV and HBV from the liver and on the other they may contribute to understand why these patients are often resistant to IFN-α-based therapies.

Impaired intrahepatic natural killer cell cytotoxic function in chronic hepatitis C virus infection

Hepatitis C virus (HCV) persistence in the host results from inefficiencies of innate and adaptive immune responses. Most studies addressing the role of innate immunity concentrated on peripheral blood (PB) natural killer (NK) cells, whereas only limited information is available on intrahepatic (IH) NK cells. We therefore examined phenotypic and functional features of IH and PB NK cells in paired liver biopsy and venous blood samples from 70 patients with chronic HCV infection and 26 control persons subjected to cholecystectomy for gallstones as controls. Ex vivo isolated IH NK cells from HCV-infected patients displayed unique phenotypic features, including increased expression of NKp46-activating receptor in the face of reduced tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and cluster of differentiation (CD) 107a expression, which resulted in impaired degranulation compared with controls. To gain insights into the effect of HCV on NK cells, we exposed peripheral blood mononuclear cells (PBMCs) from patients and healthy donors to cell-culture-derived HCV (HCVcc) and measured NK cell degranulation, TRAIL, and phosphorylated extracellular signal-regulated kinase 1/2 (pERK1/2) expression. Exposure of PBMCs to HCVcc significantly boosted NK degranulation, pERK1/2, and TRAIL expression in healthy donors, but not in patients with chronic HCV infection, a defect that was completely reversed by interferon-alpha. Purified NK cells showed a minimal, though significant, increase in degranulation and TRAIL expression, both in patients and controls, after exposure to HCVcc.

CONCLUSIONS

These findings indicate dysfunctional IH NK cell cytotoxicity associated with TRAIL down-regulation in chronic HCV infection, which may contribute to virus persistence. PB NK cell impairment upon exposure to HCVcc suggests the existence of an accessory cell-dependent NK cell lytic defect in chronic HCV infection predominantly involving the TRAIL pathway.

Therapeutic effects of L-carnitine and propionyl-L-carnitine on cardiovascular diseases: a review

Several experimental studies have shown that levocarnitine reduces myocardial injury after ischemia and reperfusion by counteracting the toxic effect of high levels of free fatty acids, which occur in ischemia, and by improving carbohydrate metabolism. In addition to increasing the rate of fatty acid transport into mitochondria, levocarnitine reduces the intramitochondrial ratio of acetyl-CoA to free CoA, thus stimulating the activity of pyruvate dehydrogenase and increasing the oxidation of pyruvate. Supplementation of the myocardium with levocarnitine results in an increased tissue carnitine content, a prevention of the loss of high-energy phosphate stores, ischemic injury, and improved heart recovery on reperfusion. Clinically, levocarnitine has been shown to have anti-ischemic properties. In small short-term studies, levocarnitine acts as an antianginal agent that reduces ST segment depression and left ventricular end-diastolic pressure. These short-term studies also show that levocarnitine releases the lactate of coronary artery disease patients subjected to either exercise testing or atrial pacing. These cardioprotective effects have been confirmed during aortocoronary bypass grafting and acute myocardial infarction. In a randomized multicenter trial performed on 472 patients, levocarnitine treatment (9 g/day by intravenous infusion for 5 initial days and 6 g/day orally for the next 12 months), when initiated early after acute myocardial infarction, attenuated left ventricular dilatation and prevented ventricular remodeling. In treated patients, there was a trend towards a reduction in the combined incidence of death and CHF after discharge. Levocarnitine could improve ischemia and reperfusion by (1) preventing the accumulation of long-chain acyl-CoA, which facilitates the production of free radicals by damaged mitochondria; (2) improving repair mechanisms for oxidative-induced damage to membrane phospholipids; (3) inhibiting malignancy arrhythmias because of accumulation within the myocardium of long-chain acyl-CoA; and (4) reducing the ischemia-induced apoptosis and the consequent remodeling of the left ventricle. Propionyl-L-carnitine is a carnitine derivative that has a high affinity for muscular carnitine transferase, and it increases cellular carnitine content, thereby allowing free fatty acid transport into the mitochondria. Moreover, propionyl-L-carnitine stimulates a better efficiency of the Krebs cycle during hypoxia by providing it with a very easily usable substrate, propionate, which is rapidly transformed into succinate without energy consumption (anaplerotic pathway). Alone, propionate cannot be administered to patients in view of its toxicity. The results of phase-2 studies in chronic heart failure patients showed that long-term oral treatment with propionyl-L-carnitine improves maximum exercise duration and maximum oxygen consumption over placebo and indicated a specific propionyl-L-carnitine effect on peripheral muscle metabolism. A multicenter trial on 537 patients showed that propionyl-L-carnitine improves exercise capacity in patients with heart failure, but preserved cardiac function.

Oxidative Stress During Myocardial Ischaemia and Heart Failure

Oxidative stress is a condition in which oxidant metabolites exert their toxic effect because of an increased production or an altered cellular mechanism of protection. The heart needs oxygen avidly and, although it has powerful defence mechanisms, it is susceptible to oxidative stress, which occurs, for instance, during post-ischaemic reperfusion. Ischaemia causes alterations in the defence mechanisms against oxygen free radicals, mainly a reduction in the activity of mitochondrial superoxide dismutase and a depauperation of tissue content of reduced glutathione. At the same time, production of oxygen free radicals increases in the mitochondria and leukocytes and toxic oxygen metabolite production is exacerbated by re-admission of oxygen during reperfusion. Oxidative stress, in turn, causes oxidation of thiol groups and lipid peroxidation leading first to reversible damage, and eventually to necrosis. In man, there is evidence of oxidative stress (determined by release of oxidised glutathione in the coronary sinus) during surgical reperfusion of the whole heart, or after thrombolysis, and it is related to transient left ventricular dysfunction or stunning. Data on oxidative stress in the failing heart are scant. It is not clear whether the defence mechanisms of the myocyte are altered or whether the production of oxygen free radicals is increased, or both. Recent data have shown a close link between oxidative stress and apoptosis. Relevant to heart failure is the finding that tumour necrosis factor, which is found increased in failing patients, induces a rapid rise in intracellular reactive oxygen intermediates and apoptosis. This series of events is not confined to the myocytes, but occurs also at the level of endothelium, where tumour necrosis factor causes expression of inducible nitric oxide synthase, production of the reactive radical nitric oxide, oxidative stress and apoptosis. It is therefore, possible that the immunological response to heart failure results in endothelial and myocyte dysfunction through oxidative stress mediated apoptosis. Clarification of these mechanisms may lead to novel therapeutic strategies.