Evidence indicates that, at least in the early stage, Kaposi's sarcoma (KS) is a cytokine-mediated disease and that it is consistently associated with a novel herpesvirus termed human herpesvirus-8 (HHV-8). To gain insights into the mechanisms by which cytokines and HHV-8 may cooperate in disease pathogenesis, we examined the phenotype, the Th1 (γ-interferon [γIFN]) and Th2 (interleukin-4 [IL-4]) cytokine profile and the presence of HHV-8 in peripheral blood mononuclear cells (PBMC), tumor-infiltrating lymphocytes (TIL), and spindle cell cultures derived from skin lesions of patients affected by classical KS (C-KS) and acquired immunodeficiency syndrome (AIDS)-associated KS (AIDS-KS). TIL and spindle cell cultures were examined at day 0 or after culture in conditioned media from activated T cells (TCM) that contain the same cytokines increased in KS tissues. No differences were found in the immunophenotype of PBMC from C-KS patients versus controls, except for AIDS-KS patients who showed a T-CD8+ expansion. However, a preferential infiltration of T-CD8+ cells was found in all KS lesions examined, which was maintained after culture of TIL in TCM. γIFN production was found in both PBMC and cultures derived from all KS examined; some IL-4 positive supernatants were found only in three AIDS-KS cases. Uninvolved skin did not show appreciable lymphocyte infiltration or cytokine production. The culture conditions of the lesional skin allowed also the appearance of adherent, spindle-like cells bearing markers of tissue macrophages. Finally, most or all of the PBMC, lesions, and macrophagic cell cultures from the skin lesions were found to be positive for HHV-8 infection by nested polymerase chain reaction (PCR). These findings indicate that patients with KS express a Th1 phenotype with a prevalent γIFN production, likely accounted for by the local T-CD8+ infiltration. By analogy with other viral infections (ie, Epstein-Barr virus), this suggests that in loco recruitment of lymphoid cells and the subsequent γIFN production may be in response to or elicited by HHV-8 that was found in both PBMC and macrophagic cell cultures from the lesions of the same patients.
Background
Few data about predictors and outcomes associated with prolonged SARS-CoV-2 RNA shedding (VS) are available.
Methods
Retrospective study including all patients admitted with COVID-19 in an Italian reference hospital for infectious diseases between March 1 and July 1, 2020. Predictors of viral clearance (VC) and prolonged VS from upper respiratory tract were assessed by Poisson regression and logistic regression analyses. The causal relation between duration of VS and probability of clinical outcomes was evaluated through inverse probability weighted Cox model.
Results
536 subjects were included. Median duration of VS from symptoms onset was 18 days (IQR 12-26). The estimated 30-day probability of VC was 70.2% (95%CI:65-75). At multivariable analysis, patients with comorbidities (aIRR = 0.88, p = 0.004), lymphopenia at hospital admission (aIRR = 0.75, p = 0.032) and with moderate/severe respiratory disease (aIRR = 0.42, p < 0.001) had a lower chance of achieving VC. The development of moderate/severe respiratory failure (aOR = 2.65, p = 0.003), a delayed hospital admission after symptoms onset (aOR = 1.18, p < 0.001), having baseline comorbidities (aOR = 1.25, p = 0.019) and D-dimer >1000 ng/mL at admission (aOR = 1.76, p = 0.035) independently predicted prolonged VS. The achievement of VC doubled the chance of clinical recovery (aHR = 2.17, p < 0.001) and reduced the probability of death/mechanical ventilation (aHR = 0.36, p = 0.002).
Conclusions
In this study, severity of respiratory disease, comorbidities, delayed hospital admission and inflammatory markers negatively predicted the achievement of VC, which resulted to be associated to better clinical outcomes. These findings highlight the importance of prompt hospitalization of symptomatic patients, especially in presence of signs of severity or comorbidities.
Evidence indicates that, at least in the early stage, Kaposi's sarcoma (KS) is a cytokine-mediated disease and that it is consistently associated with a novel herpesvirus termed human herpesvirus-8 (HHV-8). To gain insights into the mechanisms by which cytokines and HHV-8 may cooperate in disease pathogenesis, we examined the phenotype, the Th1 (γ-interferon [γIFN]) and Th2 (interleukin-4 [IL-4]) cytokine profile and the presence of HHV-8 in peripheral blood mononuclear cells (PBMC), tumor-infiltrating lymphocytes (TIL), and spindle cell cultures derived from skin lesions of patients affected by classical KS (C-KS) and acquired immunodeficiency syndrome (AIDS)-associated KS (AIDS-KS). TIL and spindle cell cultures were examined at day 0 or after culture in conditioned media from activated T cells (TCM) that contain the same cytokines increased in KS tissues. No differences were found in the immunophenotype of PBMC from C-KS patients versus controls, except for AIDS-KS patients who showed a T-CD8+ expansion. However, a preferential infiltration of T-CD8+ cells was found in all KS lesions examined, which was maintained after culture of TIL in TCM. γIFN production was found in both PBMC and cultures derived from all KS examined; some IL-4 positive supernatants were found only in three AIDS-KS cases. Uninvolved skin did not show appreciable lymphocyte infiltration or cytokine production. The culture conditions of the lesional skin allowed also the appearance of adherent, spindle-like cells bearing markers of tissue macrophages. Finally, most or all of the PBMC, lesions, and macrophagic cell cultures from the skin lesions were found to be positive for HHV-8 infection by nested polymerase chain reaction (PCR). These findings indicate that patients with KS express a Th1 phenotype with a prevalent γIFN production, likely accounted for by the local T-CD8+ infiltration. By analogy with other viral infections (ie, Epstein-Barr virus), this suggests that in loco recruitment of lymphoid cells and the subsequent γIFN production may be in response to or elicited by HHV-8 that was found in both PBMC and macrophagic cell cultures from the lesions of the same patients.
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