Infection Rate of Respiratory Viruses in the Pandemic SARS-CoV-2 Period Considering Symptomatic Patients: Two Years of Ongoing Observations.

BACKGROUND: In the last two years, the SARS-CoV-2 pandemic has determined radical changes in human behaviors and lifestyles, with a drastic reduction in socialization due to physical distancing and self-isolation. These changes have also been reflected in the epidemiological patterns of common respiratory viruses. For this reason, early discrimination of respiratory viruses is important as new variants emerge. METHODS: Nasopharyngeal swabs of 2554 patients, with clinically suspected Acute Respiratory Infections (ARIs) from October 2019 to November 2021, were collected to detect 1 or more of the 23 common respiratory pathogens, especially viruses, via BioFilmArray RP2.1plus, including SARS-CoV-2. Demographical characteristics and epidemiological analyses were performed as well as a laboratory features profile of positive patients. RESULTS: An observational study on 2300 patients (254 patients were excluded because of missing data) including 1560 men and 760 women, median age of 64.5 years, was carried out. Considering the respiratory virus research request, most of the patients were admitted to the Emergency Medicine Department (41.2%, of patients), whereas 29.5% were admitted to the Infectious Diseases Department. The most frequently detected pathogens included SARS-CoV-2 (31.06%, 707/2300, from March 2020 to November 2021), InfA-B (1.86%, 43/2300), HCoV (2.17% 50/2300), and HSRV (1.65%, 38/2300). Interestingly, coinfection rates decreased dramatically in the SARS-CoV-2 pandemic period. The significative decrease in positive rate of SARS-CoV-2 was associated with the massive vaccination. CONCLUSION: This study represents a dynamic picture of the epidemiological curve of common respiratory viruses during the two years of pandemic, with a disregarded trend for additional viruses. Our results showed that SARS-CoV-2 had a preferential tropism for the respiratory tract without co-existing with other viruses. The possible causes were attributable either to the use of masks, social isolation, or to specific respiratory receptors mostly available for this virus, external and internal lifestyle factors, vaccination campaigns, and emergence of new SARS-CoV-2 variants.

CD4+ lymphocyte increases in HIV patients during potent antiretroviral therapy are dependent on inhibition of CD8+ cell apoptosis.

Although suppression of apoptosis contributes to immune-reconstitution during potent antiretroviral therapy, its relationship with the majors indicators of response to therapy, that is, changes in CD4(+) cell counts and in viral loads (VL), is still debated. We extended our previous study by collecting data on the relationships among apoptosis and immunological and virological parameters during a long-term follow-up of HIV patients with an overall positive response to potent antiretroviral therapy. We report results from 15 patients who completed two years of therapy. In a smaller group of patients, we focused our attention on investigating the specific contribution of the CD8(+) subset in the overall changes in lymphocyte apoptosis, which occur concomitantly with the response to the therapy. Our data, while again confirming that inhibition of PBMC apoptosis is a phenomenon strictly related to a positive response to potent antiretroviral therapy, suggest that CD4(+) cell rescue is not directly dependent on inhibition of CD4(+) cell apoptosis but rather on that of the CD8(+) subset.

Inverse correlation between CD8+ lymphocyte apoptosis and CD4+ cell counts during potent antiretroviral therapy in HIV patients.

OBJECTIVES: We have addressed the relationships between inhibition of CD4+ and CD8+ cell apoptosis and CD4+ cell recovery in HIV patients undergoing potent antiretroviral therapy (PART) by correlating apoptosis levels with virological and immunological parameters detected over a long-term period in HIV patients undergoing therapy. PATIENTS AND METHODS: Twenty-two HIV-1-infected patients undergoing PART were enrolled in a long-term, open longitudinal study. Data derived from 17 patients with successful response to therapy (TS; median time of follow-up 36 months, range 24-36 months) were used for correlation studies. Apoptosis was evaluated after short-term culture of peripheral blood lymphocytes by flow cytometry analysis of isolated nuclei or of annexin V/CD4, annexin V/CD8 double-stained cells. RESULTS: Sustained, noticeable levels of apoptosis inhibition in peripheral blood mononuclear cells were measured, in the long-term, in 16 of the 17 TS patients. Levels of total cell apoptosis correlated with levels of CD8+ apoptotic cells more significantly than with levels of CD4+ apoptotic cells. In addition, CD4+ cell counts were correlated inversely with levels of CD8+ apoptotic cells in a highly significant fashion, but not with levels of CD4+ apoptotic cells. CONCLUSIONS: Our data indicate that the increase of CD4+ lymphocytes in HIV patients, as a consequence of successful response to PART, may be related to changes in apoptosis level occurring in the CD8+, and not in the CD4+, cell compartment.