Heightened Circulating Interferon-Inducible Chemokines, and Activated Pro-Cytolytic Th1-Cell Phenotype Features Covid-19 Aggravation in the Second Week of Illness.

Covid-19 features a delayed onset of critical illness occurring approximately one week from the beginning of symptoms, which corresponds to the bridging of innate and adaptive immunity. We reasoned that the immune events occurring at the turning point of disease might mark the direction toward pathogenic versus protective inflammatory responses. Subjects with either severe (s; PaO2/FiO2 ratio <200) or mild (m; PaO2/FiO2 ratio>300) Covid-19 were enrolled. A range of chemokines and cytokines as well as reactive oxygen species (ROS) were measured in plasma. Dendritic and NK cell frequency, monocyte and B-/T-cell phenotype and SARS-CoV-2-specific T-cell responses were assessed in PBMC. Twenty mCovid-19 and 20 sCovid-19 individuals were studied. sCovid-19 patients displayed higher non-classical monocytes, plasma chemokines (CXCL8, CXCL9, CXCL10), cytokines (IL-6, IL-10), and ROS versus mCovid-19. sCovid-19 also showed significantly increased activated CD38+HLA-DR+ T-lymphocyte, and granzyme-B+/perforin+ pro-cytolytic T-cells. All Covid-19 patients showed SARS-CoV-2 specific-T-cell response with a predominance of Th1 bi- or trifunctional IFN-γ/IL-2/TNF-α-expressing CD4+, while no difference according to disease severity was observed. Severe Covid-19 features heightened circulating IFN-inducible chemokines and activated pro-cytolytic Th1 cell phenotype in the second week of illness, yet SARS-CoV-2-specific responses are similar to that of mild illness. Altogether, our observations suggest Th1 polarization coupled to higher cytolytic profile in sCovid-19 as correlate of disease pathogenesis and as potential targets to be investigated in the roadmap to therapy and vaccine development.

Association Between Impaired Vα7.2+CD161++CD8+ (MAIT) and Vα7.2+CD161-CD8+ T-Cell Populations and Gut Dysbiosis in Chronically HIV- and/or HCV-Infected Patients.

Both HIV and HCV infections feature increased microbial translocation (MT) and gut dysbiosis that affect immune homeostasis and disease outcome. Given their commitment to antimicrobial mucosal immunity, we investigated mucosal-associated invariant T (MAIT) cells and Vα7.2+CD161- T-cell frequency/function and their possible associations with MT and gut dysbiosis, in chronic HIV and/or HCV infections. We enrolled 56 virally infected (VI) patients (pts): 13 HIV+ on suppressive cART (HIV-RNA < 40cp/ml), 13 HCV+ naive to DAA (direct-acting antiviral) anti-HCV agents; 30 HCV+/HIV+ on suppressive cART and naive to anti-HCV. 13 age-matched healthy controls (HC) were enrolled. For Vα7.2+CD161++ and Vα7.2+CD161-CD8+ T cells we assessed: activation (CD69), exhaustion (PD1/CD39), and cytolytic activity (granzymeB/perforin). Following PMA/ionomycin and Escherichia coli stimulation we measured intracellular IL17/TNFα/IFNγ. Markers of microbial translocation (Plasma LPS, 16S rDNA, EndoCAb and I-FABP) were quantified. In 5 patients per group we assessed stool microbiota composition by 16S targeted metagenomics sequencing (alpha/beta diversity, relative abundance). Compared to controls, virally infected pts displayed significantly lower circulating Vα7.2+CD161++CD8+ MAIT cells (p = 0.001), yet expressed higher perforin (p = 0.004) and granzyme B (p = 0.002) on CD8+ MAIT cells. Upon E. coli stimulation, the residual MAIT cells are less functional particularly those from HIV+/HCV+ patients. Conversely, in virally infected pts, Vα7.2+CD161-CD8+ cells were comparable in frequency, highly activated/exhausted (CD69+: p = 0.002; PD-1+: p = 0.030) and with cytolytic potential (perforin+: p < 0.0001), yet were poorly responsive to ex vivo stimulation. A profound gut dysbiosis characterized virally infected pts, especially HCV+/HIV+ co-infected patients, delineating a Firmicutes-poor/Bacteroidetes-rich microbiota, with significant associations with MAIT cell frequency/function. Irrespective of mono/dual infection, HIV+ and HCV+ patients display depleted, yet activated/cytolytic MAIT cells with reduced ex vivo function, suggesting an impoverished pool, possibly due to continuous bacterial challenge. The MAIT cell ability to respond to bacterial stimulation correlates with the presence of Firmicutes and Bacteroidetes, possibly suggesting an association between gut dysbiosis and MAIT cell function and posing viral-mediated dysbiosis as a potential key player in the hampered anti-bacterial MAIT ability.

Unconventional T cells in chronic hepatitis B patients on long-term suppressive therapy with tenofovir followed by a Peg-IFN add-on strategy: A randomized study.

HBV eradication in chronic hepatitis B (CHB) subjects is rarely achieved with either nucleos(t)ide analogues (NA) or pegylated interferon (Peg-IFN), which both have a limited effect in restoring immune responses. Thirty CHB subjects on long-term treatment with tenofovir (TDF) and HBV suppression were enrolled and randomized 1:2 to either receive Peg-IFN-α-2a add-on therapy or continue TDF alone. We studied γδ T and iNKT frequency and function (by flow cytometry) at baseline, at 12 weeks and 12 weeks after the end of treatment. A higher reduction in qHBsAg occurred in the add-on group compared with the NA group at W12 (P = .016) and at W24 (P = .012). A decline of qHBsAg ≥0.5 log10 at week 24 occurred in 4 of 10 patients in the add-on arm and 1 of 20 in the NA arm, respectively (P = .03). HBsAg loss was seen in 20% of subjects in the add-on group and in none of the NA group. Compared to HBV negative, CHB on TDF showed lower frequency of iNKT (P = .03) and γδ T cells (P = .03) as well as fewer γδ T cells expressing Vδ2 T-cell receptors (P = .005). No changes in unconventional T-cell frequency and function were shown in both add-on and NA patients nor were differences detected between the two treatment groups. We report persistent impairment of unconventional T cells in CHB. Despite a greater qHBsAg decline of add-on patients, our data failed to detect any effect of Peg-IFN treatment on unconventional T cells.

T-cell phenotype and function following a first cART regimen containing either a protease inhibitor or a non-nucleoside reverse transcriptase inhibitor in HIV-infected late presenters: results from a retrospective, ex vivo study.

BACKGROUND: We aimed to comparatively assess darunavir/ritonavir (DRV/r) and efavirenz (EFV)-based first-line cART regimens in the reconstitution of T-cell phenotype and function in HIV-infected, late presenter subjects. METHODS: Retrospective, ex vivo study on stored peripheral blood mononuclear cell samples of cART-naive, HIV-infected individuals with CD4(+) T-cell counts <50>250/µl upon cART initiation with either DRV/r or EFV as third drugs of standard antiretroviral regimens. CD4(+) and CD8(+) T-cell maturation (CCR7/CD45RA) and proliferation (Ki67), CD8(+) T-cell activation (CD38/HLA-DR) as well as HIV- and cytomegalovirus (CMV)-specific responses (CD4/CD8/IL-2/IFN-γ) were studied by flow cytometry at baseline (T0), T3, T6 and T12 months. Soluble inflammatory markers (IL-6 and sCD14) were measured in plasma at T0 and T12. Wilcoxon and Mann-Whitney tests were used for statistics. RESULTS: A total of 19 patients started DRV/r and 15 EFV. Both regimens accounted for suppression of the HIV RNA load (<40 copies/ml), reconstitution of absolute CD4(+) T-cells and CD4(+)/CD8(+) T-cell ratio. All study participants displayed a significant decrease of activated HLA-DR(+)CD38(+) CD8(+) T-cells at all study time points, yet no differences were found between study groups in T-cell activation and maturation phenotype. From a functional standpoint, only individuals receiving DRV/r displayed transitory recovery of HIV-specific IL-2(+)IFN-γ(-) CD4(+) T-cells (T3: P=0.006) and IL-2(-)IFN-γ(+) CD8(+) T-cells (T3: P=0.032). CONCLUSIONS: DRV/r- and EFV-based regimens have an equal effect on T-cell phenotype and function in HIV late presenters. A temporary restoration of HIV-specific T-cell immunity early in the course of therapy with DRV/r possibly implies a more effective control over HIV in the first months following a PI/r-based regimen, even at late stage of disease.

Multiparameter immunophenotyping by flow cytometry as a diagnostic tool in multiple myeloma and monoclonal gammopathy of undetermined significance.

BACKGROUND: Immunophenotyping by multiparameter flow cytometry (MFC) provides relevant information about prognosis and minimal residual disease detection in multiple myeloma (MM) and might be used to distinguish MM from monoclonal gammopathies of undetermined significance (MGUS). MATERIALS AND METHODS: We evaluated a possible usage of MFC to predict the differential diagnosis between MM and MGUS. One hundred consecutive patients were studied at diagnosis and underwent conventional diagnostic procedures. We carried out a double-blind study. Immunophenotyping was performed on samples from myeloaspirates before establishing diagnosis, while the final clinical diagnosis was established independently from MFC results. A five- or six-color method was carried out by means of monoclonal antibody combinations able to identify abnormal plasma cells (CD19-) and the most relevant immunophenotypic aberrations (loss of CD27; overexpression of CD117, CD56, CD28; asynchronous expression of CD20). MFC was applied following the indications of the European Myeloma Network. When abnormal plasma cells were /= 3.1%, MGUS was predicted. RESULTS: MFC results predicted 63 cases of MM and 37 cases of MGUS. At the end of our study, 61 cases of MM and 39 cases of MGUS were diagnosed. Therefore, 4% of patients were misdiagnosed by MFC parameters alone, with sensitivity and specificity of 0.983 and 0.92, respectively. CONCLUSIONS: Only a small proportion of patients with MM and MGUS were misdiagnosed by MFC alone and a possible systematic application of MFC in all patient with MM and MGUS at diagnosis might be proposed. Novel additional criteria could be necessary to improve the diagnostic impact of MFC in monoclonal gammopathies.

Combination of morphology, flow cytometry and PCR assay to detect bone marrow infiltration in B-cell non-Hodgkin's lymphomas.

AIMS: Morphology on bone marrow biopsy (BMB) samples has historically been the primary method used to detect bone marrow (BM) infiltration in B-cell non-Hodgkin's lymphoma (NHL), while fl ow cytometry (FC) and PCR assays have been generally used as ancillary methods. In this study we evaluated a combined approach utilizing all three methods to detect BM infiltration in patients with NHL both at diagnosis and after therapy. MATERIALS AND METHODS: We analyzed 193 patients with NHL, who received simultaneous BMB, FC and PCR assays. Morphology on histologic specimens was used to assess infiltration pattern and immunohistochemistry, FC to analyze immunophenotype, PCR to identify IgH rearrangement, BCL-1/JH and BCL-2/JH translocation. RESULTS: Morphology, FC and PCR assays agreed in 142 cases (73.5%) with more concordance at initial diagnosis than during postchemotherapy follow-up. PCR was the single best-performing test, while combination of morphology and PCR yielded a higher sensitivity than individual methods and was similar to PCR + FC. We observed little added benefit using a third approach. CONCLUSION: Given the initial importance of histological information evident by morphology, our data suggest that combination of morphology and PCR should be considered the gold standard for evaluation of BM infiltration at diagnosis, while combination of PCR + FC should be employed during post-treatment follow-up.

Recombinant human granulocyte colony-stimulating factor administration in a case of neutropenia due to increased neutrophil sequestration.

A 55-year-old female was admitted with fever which followed an episode of pseudomembranous colitis. Despite an accurate clinical investigation, there was no evidence for specific sites of infection. Remission of fever was not obtained with antibiotic therapy (gentamycin plus carbepenem) and progressive neutropenia was observed. Neutrophils fell to 0.3 x 10(9)/1. The diagnostic approach, including a bone marrow aspirate, excluded mechanisms leading to impaired neutrophil production, and in the suspect of increased neutrophil sequestration/destruction, whole-body scintigraphy with (99m)technetium-hexamethylpropyleneamineoxime ((99m)Tc-HMPAO)-labeled autologous leukocytes was performed. As a result, a site of leukocyte sequestration localized at the medium lobe of the right lung was detected. In an attempt to enhance neutrophil functions and achieve remission of infection, recombinant human granulocyte colony-stimulating factor (Filgrastim, Granulokine 30, Roche) at the dosage of 300 microg/day, subcutaneously, was added. As a results, fever disappeared in three days, but neutrophil recovery was slower, and normalization of the absolute neutrophil count (ANC) was obtained on day +7. The results obtained in this peculiar case of neutropenia, and the kinetics of both fever and ANC, suggest the possible combination of neutrophil function enhancement and an anti-inflammatory effect of rhG-CSF.