Toll-like receptor 4-dependent and Independent platelet-dependent thrombosis in SARS-CoV-2 infection

Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is associated with an increased risk of venous and arterial thrombosis but the underlying mechanism if still unclear. Aim(s): The study would identify a mechanism implicated in platelet activation and thrombus growth during SARS-CoV-2 infection. Method(s): We performed a cross-sectional analysis of platelet function in 30 SARS-CoV-2 and 20 healthy subjects (HS) by measuring Nox2-derived oxidative stress and thromboxane (Tx) B2 and investigated if administration of monoclonal antibodies against the Spike(S) protein of SARS-CoV-2 affects platelet activation. Furthermore, we investigated in vitro if the Spike(S) protein of SARS-CoV-2 or plasma from SARS-CoV-2 enhanced platelet activation. Result(s): Ex vivo studies showed enhanced platelet Nox2-derived oxidative stress and TxB2 biosynthesis and under laminar flow platelet-dependent thrombus growth in SARS-CoV-2 compared to controls;both effects were lowered by Nox2 and Toll-like receptor 4(TLR4) inhibitors. Two hours after administration of monoclonal antibodies a significant inhibition of platelet activation was observed in SARS-CoV-2 patients compared to untreated ones. In vitro study showed that S protein functionally interacts with platelet TLR4, and a docking simulation analysis suggested that TLR4 binds to S protein via three receptor-binding domains;furthermore, in platelets from SARS-CoV-2 S protein co-immunoprecipitated with TLR4. Plasma from SARS-CoV-2 patients incubated with normal platelets enhanced platelet activation and Nox2-related oxidative stress, an effect blunted by TNF-alpha inhibitor;this effect was recapitulated by an in vitro study documenting that TNF-alpha alone promoted platelet activation and amplified the platelet response to S protein via p47phox up-regulation. Conclusion(s): The study identifies two TLR4-dependent and independent pathways promoting platelet-dependent thrombus growth and suggests inhibition of TLR4 or p47phox as a tool to counteract thrombosis in SARS-CoV-2.

Clinical course of Coronavirus Disease-19 in patients with haematological malignancies is characterized by a longer time to respiratory deterioration compared to non-haematological ones: results from a case-control study.

BACKGROUND: We evaluated clinical features and risk factors for mortality in patients with haematological malignancies and COVID-19. METHODS: Retrospective, case-control (1:3) study in hospitalized patients with COVID-19. Cases were patients with haematological malignancies and COVID-19, controls had COVID-19 without haematological malignancies. Patients were matched for sex, age and time of hospitalization. RESULTS: Overall, 66 cases and 198 controls were included in the study. Cases had higher prior corticosteroid use, infection rates, thrombocytopenia and neutropenia and more likely received corticosteroids and antibiotics than controls. Cases had higher respiratory deterioration than controls (78.7% vs 65.5%, p = 0.04). Notably, 29% of cases developed respiratory worsening > 10 days after hospital admission, compared to only 5% in controls. Intensive Care Unit admission and mortality were higher in cases than in controls (27% vs 8%, p = 0.002, and 35% vs 10%, p < 0.001). At multivariable analysis, having haematological malignancy [OR4.76, p < 0.001], chronic corticosteroid therapy [OR3.65, p = 0.004], prior infections [OR57.7, p = 0.006], thrombocytopenia [OR3.03, p < 0.001] and neutropenia [OR31.1, p = 0.001], low albumin levels [OR3.1, p = 0.001] and ≥ 10 days from hospital admission to respiratory worsening [OR3.3, p = 0.002] were independently associated with mortality. In cases, neutropenia [OR3.1, p < 0.001], prior infections [OR7.7, p < 0.001], ≥ 10 days to respiratory worsening [OR4.1, p < 0.001], multiple myeloma [OR1.5, p = 0.044], the variation of the CT lung score during hospitalization [OR2.6, p = 0.006] and active treatment [OR 4.4, p < 0.001] all were associated with a worse outcome. CONCLUSION: An underlying haematological malignancy was associated with a worse clinical outcome in COVID-19 patients. A prolonged clinical monitoring is needed, since respiratory worsening may occur later during hospitalization.

DIFFERENTIAL IFN GENES EXPRESSION in the UPPER AIRWAYS of CHILDREN and ADULTS

Background: Children generally develop a mild disease after SARS-CoV-2 infection;it has been shown (Loske J al., 2021) that higher basal expression of relevant pattern recognition receptors may result in a stronger early innate antiviral than in adults. However, how the early interferon (IFN) response differs from that in adults is not fully characterized. Hence, we aimed to investigate the expression of several IFN-related genes in nasopharyngeal (NP) cells from children and adults with asymptomatic or mild COVID-19, not requiring hospitalization. Methods: Children and adults attending emergency departments (ED) of Sapienza University Hospital, to perform SARS-CoV-2 molecular tests, were enrolled from November 2020 to February 2021, after informed consent was obtained. RNA from residual NP swabs was purified and 200 ng were reverse transcribed. Gene expression of genes coding for type I and III IFNs and for the well-known markers of IFNs' activation, ISG15 and ISG56, was measured by exonuclease-based Real time PCR assays with relative quantification to the invariant gene GUS (the 2-ΔCt method). Results: Residual NP cells from a total of 132 children and adults were included in the study;56 had SARS-CoV-2 positive results and 76 resulted negative. The expression of all tested genes showed a moderate significant inverse correlation with age, with the exception of ISG15. Participants were further stratified in age groups (< 16;16-35;36-65 years) resulting in: 25 SARS-CoV-2 negative and 26-positive children;14 SARS-CoV-2 negative and 16-positive young adults and 37 SARS-CoV-2 negative and 14-positive adults. In SARS-CoV-2 negative samples, higher levels of all study genes were found in children, while significantly decreasing in young and elderly adults. Among SARS-CoV-2 positive samples, those from children showed significantly higher levels of type I IFNs and of IFN lambda2 whereas ISG15 was far more elevated in adults. Moreover, levels of all type I IFNs, and of IFN lambda2, were significantly higher in individuals with no symptoms (65% of children and 44% of the young adults), whereas ISG15 was elevated in those with a mild COVID-19. Conclusion: The higher baseline expression of IFN-related genes in children may prompt a quicker activation of the IFN response after SARS-CoV-2 infection and contribute to effective control of viral replication;the higher ISG activation in adults may be caused by the inflammatory response and associated to COVID-19 symptoms.

Convalescent plasma for haematological patients with SARS-CoV-2 pneumonia and severe depletion of B-cell lymphocytes following anti-CD20 therapy: a single-centre experience and review of the literature

Convalescent plasma (CP) therapy might be effective in patients with haematological malignanciesand B-cell depletion. We report a single-centre experience of COVID-19 patients with non-Hodgkinlymphoma and absence of B-cells as a consequence of anti-CD20 therapy successfully treated withCP from October 2020 to May 2021. CP was given in the presence of pneumonia with respiratoryfailure despite standard treatment and consisted of three infusions on an alternate-day basis. A reviewof the current literature on this topic was also performed. Six patients were identified (medianage 59.5 years (range 50-73)). The last anti-CD20 drug administration occurred 60 days before infection(range 0-360). CP was administered after a median of 51 days (range 9-120) from SARS-CoV-2diagnosis, with an early improvement in all but one subject. We suggest a possible clinical benefitof convalescent CP treatment in COVID-19 patients with haematological malignancies and B-celldepletion having persistent/recurrent pneumonia.

Molecular diagnosis of SARS-CoV-2 in seminal fluid.

PURPOSE: Due to relevant repercussions on reproductive medicine, we aimed to evaluate feasibility of RT-PCR as a detection method of SARS-CoV-2 RNA in seminal fluid. METHODS: A qualitative determination of the RT-PCR assays in semen was performed through different approaches: (1) efficiency of RNA extraction from sperm and seminal plasma was determined using PRM1 and PRM2 mRNA and a heterologous system as control; (2) samples obtained by diluting viral preparation from a SARS-CoV-2 panel (virus cultured in Vero E6 cell lines) were tested; (3) viral presence in different fractions of seminal fluid (whole sample, seminal plasma and post-centrifugation pellet) was evaluated. Semen samples from mild and recovered COVID-19 subjects were collected by patients referring to the Infectious Disease Department of the Policlinico Umberto I Hospital - "Sapienza" University of Rome. Control subjects were recruited at the Laboratory of Seminology-Sperm Bank "Loredana Gandini'' of the same hospital. RESULTS: The control panel using viral preparations diluted in saline and seminal fluid showed the capability to detect viral RNA presence with Ct values depending on the initial viral concentration. All tested semen samples were negative for SARS-CoV-2, regardless of the nasopharyngeal swab result or seminal fluid fraction. CONCLUSION: These preliminary data show that RT-PCR for SARS-CoV-2 RNA testing appears to be a feasible method for the molecular diagnosis of SARS-CoV-2 in seminal fluid, supported by results of the control panel. The ability to detect SARS-CoV-2 in semen is extremely important for reproductive medicine, especially in assisted reproductive technology and sperm cryopreservation.

Determinants of prolonged viral RNA shedding in hospitalized patients with SARS-CoV-2 infection.

OBJECTIVE: To evaluate determinants of prolonged viral RNA shedding in hospitalized patients with SARS-CoV-2 infection. MATERIALS AND METHODS: Hospitalized patients with SARS-CoV-2 positive nasopharyngeal RT-PCR were included in a single-center, retrospective study. Patients were divided in 2 groups according to the timing of viral clearance [≤14 days, "early clearance (EC)" and >14 days, "late clearance (LC)"]. RESULTS: 179 patients were included in the study (101 EC, 78 LC), with median age 62 years. Median time of viral shedding was 14 days (EC/LC 10 and 19 days, respectively, P < 0.0001). Univariate analyses showed that age, male gender, receiving corticosteroids, receiving tocilizumab, ICU admission, low albumin and NLR ratio were associated with late viral clearance. In the multivariable analysis, older age (P = 0.016), albumin level (P = 0.048), corticosteroids (P = 0.021), and tocilizumab (P = 0.015) were significantly associated with late viral clearance. CONCLUSIONS: Age, albumin, tocilizumab and corticosteroid treatment were independently associated with a prolonged SARS-CoV-2 RNA shedding.

Sperm cryopreservation during the SARS-CoV-2 pandemic.

PURPOSE: Sperm cryopreservation is fundamental in the management of patients undergoing gonadotoxic treatments. Concerns have risen in relation to SARS-CoV-2 and its potential for testicular involvement, since SARS-CoV-2-positive cryopreserved samples may have unknown effects on fertilization and embryo safety. This study therefore aimed to analyze the safety of sperm cryopreservation for cancer patients after the onset of the pandemic in Italy, through assessment of the risk of SARS-CoV-2 exposure and viral RNA testing of semen samples. METHODS: We recruited 10 cancer patients (mean age 30.5 ± 9.6 years) referred to our Sperm Bank during the Italian lockdown (from March 11th to May 4th 2020) who had not undergone a nasopharyngeal swab for SARS-CoV-2 testing. Patients were administered a questionnaire on their exposure to COVID-19, and semen samples were taken. Before cryopreservation, SARS-CoV-2 RNA was extracted from a 150 µl aliquot of seminal fluid in toto using QIAamp viral RNA kit (Qiagen) and amplified by a real time RT PCR system (RealStar SARS-CoV2 RT PCR, Altona Diagnostics) targeting the E and S genes. RESULTS: The questionnaire and medical interview revealed that all patients were asymptomatic and had had no previous contact with COVID-19 infected patients. All semen samples were negative for SARS-CoV-2 RNA. CONCLUSION: This preliminary assessment suggests that a thorough evaluation (especially in the setting of a multidisciplinary team) and molecular confirmation of the absence of SARS-CoV-2 in seminal fluid from asymptomatic cancer patients may assist in ensuring the safety of sperm cryopreservation.

Study of SARS-CoV-2 in semen and urine samples of a volunteer with positive naso-pharyngeal swab.

INTRODUCTION: The recent appearance of SARS-CoV-2 in Wuhan in 2019 has started a pandemic which has involved over a million people worldwide. A matter of debate is the possible viral detection in different body fluids than respiratory droplets. Thus, we evaluated the possible presence of SARS-CoV-2 in semen and urine samples of a volunteer with confirmed COVID-19. MATERIALS AND METHODS: A 31-year-old man with fever, myalgia, anosmia, and ageusia was tested and found positive for SARS-CoV-2 through a pharyngeal swab. Eight days after he provided semen and urine samples in which viral RNA presence was measured using a Real time RT PCR system (RealStar SARS-CoV-2 RT-PCR, Altona Diagnostics) targeting E and S viral genes. RESULTS AND DISCUSSION: Semen and urine samples search for SARS-CoV-2 RNA was negative. Although this should be interpreted cautiously, it may be possible that either the viral clearance kinetics in these matrices matches the progressive clinical recovery of the patient or that the virus was never present in these fluids at the time of the laboratory diagnosis.