Bacteremia from streptococcus constellatus revealing a gastrointestinal stromal tumor.

BACKGROUND: Pyogenic Liver Abscesses (PLA) are the most common type of visceral abscess. They generally develop in a context of biliary disease or hematogenous seeding, but a complete diagnostic work-up is always required in order not to miss other important causes, including above all malignancies of the gastro-intestinal tract. CASE PRESENTATION: Herein, we report a particular case of a 80 years-old immunocompetent woman hospitalized for sepsis. At the end of the diagnostic process, Streptococcus constellatus (Sc) was identified as the cause of sepsis, multiple PLA were found together with a previous unknown ileal malignancy. We speculated about a possible correlation among these three entities (i.e. sepsis from Sc, PLA and tumors). CONCLUSIONS: Detection of Sc in blood should raise red flags in clinicians as aggressive clinical presentation are possible.

HCV treatment in Sardinian HIV-HCV coinfected patients: a real-life perspective study on safety, efficacy, and immune reconstitution.

BACKGROUND: HIV-HCV co-infected patients have long been considered difficult-to-treat. The introduction of direct-acting antivirals (DAAs) changed this paradigm.We evaluated the efficacy and safety of DAA-based regimens and the impact of DAAs-induced HCV clearance on the immunological status in HIV-HCV co-infected patients. RESEARCH DESIGN AND METHODS: HIV patients starting HCV treatment with DAAs were included. Sustained virological response at 12 weeks after DAAs treatment (SVR12) was assessed. CD4+ and CD8+ blood cell count and CD4+/CD8+ ratio were recorded at baseline and six months post DAA treatment. We enrolled 201 patients, 76.1% males, median age 54 years, the most common genotypes 3 (29.8%) and 1a (29.4%), 40.3% with cirrhosis, 32.3% with prior interferon-based treatment. All patients were on antiretroviral treatment, 24.4% on methadone maintenance therapy and 22.6% on psychotropic drugs. RESULTS: SVR12 was 98.4%, the most common side effects were pruritus (8.4%), headache (7.4%) and fatigue (5.9%). An increase in CD4+ and CD8+ cell count was observed six months after completion of DAAs treatment, in particular in patients with low CD4+ cell count at baseline. CONCLUSIONS: DAAs treatment resulted in high SVR12 rates, was well tolerated and Increased CD4+ and CD8+, especially in patients with low CD4+ cell count at baseline.

Natural killer-cell immunoglobulin-like receptors trigger differences in immune response to SARS-CoV-2 infection.

BACKGROUND: The diversity in the clinical course of COVID-19 has been related to differences in innate and adaptative immune response mechanisms. Natural killer (NK) lymphocytes are critical protagonists of human host defense against viral infections. It would seem that reduced circulating levels of these cells have an impact on COVID-19 progression and severity. Their activity is strongly regulated by killer-cell immuno-globulin-like receptors (KIRs) expressed on the NK cell surface. The present study's focus was to investigate the impact of KIRs and their HLA Class I ligands on SARS-CoV-2 infection. METHODS: KIR gene frequencies, KIR haplotypes, KIR ligands and combinations of KIRs and their HLA Class I ligands were investigated in 396 Sardinian patients with SARS-CoV-2 infection. Comparisons were made between 2 groups of patients divided according to disease severity: 240 patients were symptomatic or paucisymptomatic (Group A), 156 hospitalized patients had severe disease (Group S). The immunogenetic characteristics of patients were also compared to a population group of 400 individuals from the same geographical areas. RESULTS: Substantial differences were obtained for KIR genes, KIR haplotypes and KIR-HLA ligand combinations when comparing patients of Group S to those of Group A. Patients in Group S had a statistically significant higher frequency of the KIR A/A haplotype compared to patients in Group A [34.6% vs 23.8%, OR = 1.7 (95% CI 1.1-2.6); P = 0.02, Pc = 0.04]. Moreover, the KIR2DS2/HLA C1 combination was poorly represented in the group of patients with severe symptoms compared to those of the asymptomatic-paucisymptomatic group [33.3% vs 50.0%, OR = 0.5 (95% CI 0.3-0.8), P = 0.001, Pc = 0.002]. Multivariate analysis confirmed that, regardless of the sex and age of the patients, the latter genetic variable correlated with a less severe disease course [ORM = 0.4 (95% CI 0.3-0.7), PM = 0.0005, PMC = 0.005]. CONCLUSIONS: The KIR2DS2/HLA C1 functional unit resulted to have a strong protective effect against the adverse outcomes of COVID-19. Combined to other well known factors such as advanced age, male sex and concomitant autoimmune diseases, this marker could prove to be highly informative of the disease course and thus enable the timely intervention needed to reduce the mortality associated with the severe forms of SARS-CoV-2 infection. However, larger studies in other populations as well as experimental functional studies will be needed to confirm our findings and further pursue the effect of KIR receptors on NK cell immune-mediated response to SARS-Cov-2 infection.