Time-resolved systems immunology reveals a late juncture linked to fatal COVID-19.

COVID-19 exhibits extensive patient-to-patient heterogeneity. To link immune response variation to disease severity and outcome over time, we longitudinally assessed circulating proteins as well as 188 surface protein markers, transcriptome, and T cell receptor sequence simultaneously in single peripheral immune cells from COVID-19 patients. Conditional-independence network analysis revealed primary correlates of disease severity, including gene expression signatures of apoptosis in plasmacytoid dendritic cells and attenuated inflammation but increased fatty acid metabolism in CD56dimCD16hi NK cells linked positively to circulating interleukin (IL)-15. CD8+ T cell activation was apparent without signs of exhaustion. Although cellular inflammation was depressed in severe patients early after hospitalization, it became elevated by days 17-23 post symptom onset, suggestive of a late wave of inflammatory responses. Furthermore, circulating protein trajectories at this time were divergent between and predictive of recovery versus fatal outcomes. Our findings stress the importance of timing in the analysis, clinical monitoring, and therapeutic intervention of COVID-19.

Perturbations of the T-cell receptor repertoire in response to SARS-CoV-2 in immunocompetent and immunocompromised individuals.

BACKGROUND: Functional T-cell responses are essential for virus clearance and long-term protection after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, whereas certain clinical factors, such as older age and immunocompromise, are associated with worse outcome. OBJECTIVE: We sought to study the breadth and magnitude of T-cell responses in patients with coronavirus disease 2019 (COVID-19) and in individuals with inborn errors of immunity (IEIs) who had received COVID-19 mRNA vaccine. METHODS: Using high-throughput sequencing and bioinformatics tools to characterize the T-cell receptor ß repertoire signatures in 540 individuals after SARS-CoV-2 infection, 31 IEI recipients of COVID-19 mRNA vaccine, and healthy controls, we quantified HLA class I- and class II-restricted SARS-CoV-2-specific responses and also identified several HLA allele-clonotype motif associations in patients with COVID-19, including a subcohort of anti-type 1 interferon (IFN-1)-positive patients. RESULTS: Our analysis revealed that elderly patients with COVID-19 with critical disease manifested lower SARS-CoV-2 T-cell clonotype diversity as well as T-cell responses with reduced magnitude, whereas the SARS-CoV-2-specific clonotypes targeted a broad range of HLA class I- and class II-restricted epitopes across the viral proteome. The presence of anti-IFN-I antibodies was associated with certain HLA alleles. Finally, COVID-19 mRNA immunization induced an increase in the breadth of SARS-CoV-2-specific clonotypes in patients with IEIs, including those who had failed to seroconvert. CONCLUSIONS: Elderly individuals have impaired capacity to develop broad and sustained T-cell responses after SARS-CoV-2 infection. Genetic factors may play a role in the production of anti-IFN-1 antibodies. COVID-19 mRNA vaccines are effective in inducing T-cell responses in patients with IEIs.

Long-term symptoms after SARS-CoV-2 infection in a cohort of people living with HIV.

BACKGROUND: Our Hospital in Northern Italy assists 3817 people living with HIV (PLWH) and has faced the impact of COVID-19. Little is known about the impact of HIV infection on the risk of post-COVID-19 conditions (PCCs) onset. We aim to assess the incidence of PCC in PLWH and the factors associated with its occurrence. METHODS: We performed a retrospective, observational study including all PLWH > 18 years registered in the Brescia Health Protection Agency database, assessing SARS-CoV-2 burden, vaccination status, socio-demographic, and viro-immunological parameters from February 2020 until May 2022. Persistence of self-reported symptoms (clustered into gastrointestinal, respiratory, osteo-muscular, and neuro-behavioral symptoms) was evaluated after 3 months by a telephone-administered questionnaire. We estimated the associations between all variables and outcomes through univariate and multivariable logistic models. RESULTS: In the study period, 653 PLWH were diagnosed with SARS-CoV-2 infection (17.1%). We observed 19 (2.9%) reinfections, 71 (10.9%) hospitalizations, and 3 (0.5%) deaths. We interviewed 510/653 PLWH (78%), and 178 (PCCs prevalence 34.9%; CI 95% 30.7-39.2) reported persistent symptoms. Asthenia/fatigue was the most reported symptom (60/178), followed by muscular pain (54/178). In the multivariate regression model, there was a lower risk of PCCs in males respect to females (adjusted OR = 0.64; CI 95% 0.99-3.66), while hospitalization during acute infection was associated with an increased the risk of PCCs (adjusted OR = 1.9; CI 95% 0.99-3.66). Notably, no viro-immunological variable modified the PCCs risk onset. CONCLUSIONS: Our study highlights a substantial prevalence of PCCs among PLWH, three months post-SARS-CoV-2 infection, independent of viro-immunological features or vaccination status.

Finger nodules with a papulovesicular hands and feet eruption: a complicated human Orf virus infection.

BACKGROUND: Orf virus (ORFV) is the pathogen responsible for Orf, a zoonotic viral infection that can be spread to humans from sheep and goats. Here, we present a case of human Orf complicated by an immune-related reaction, to raise awareness of this under-recognized disease avoiding unnecessary investigations and overtreatment. CASE REPORT: A 51-year-old woman with no previous medical history presented with a one-week history of three asymptomatic swelling nodules with a grey necrotic center and red outer halo on her index finger. At physical examination there was also a pruritic papulovesicular eruption on her hands and feet. She reported a recent contact with a goat which had a similar nodular lesion in its mouth. A biopsy of the lesions was performed and a diagnosis of Orf complicated by widespread erythema multiforme was made based on the clinical and histopathological features. The lesions spontaneously resolved within the next 2 weeks. CONCLUSIONS: Orf is not very prevalent in our region, so we performed a biopsy of the lesion to guide us toward a diagnosis. However, we should remember that the diagnosis of ecthyma relies on clinical evaluation and epidemiological criteria.

Dolutegravir and Folic Acid Interaction during Neural System Development in Zebrafish Embryos.

Dolutegravir (DTG) is one of the most prescribed antiretroviral drugs for treating people with HIV infection, including women of child-bearing potential or pregnant. Nonetheless, neuropsychiatric symptoms are frequently reported. Early reports suggested that, probably in relation to folic acid (FA) shortage, DTG may induce neural tube defects in infants born to women taking the drug during pregnancy. Subsequent reports did not definitively confirm these findings. Recent studies in animal models have highlighted the association between DTG exposure in utero and congenital anomalies, and an increased risk of neurologic abnormalities in children exposed during in utero life has been reported. Underlying mechanisms for DTG-related neurologic symptoms and congenital anomalies are not fully understood. We aimed to deepen our knowledge on the neurodevelopmental effects of DTG exposure and further explore the protective role of FA by the use of zebrafish embryos. We treated embryos at 4 and up to 144 h post fertilization (hpf) with a subtherapeutic DTG concentration (1 µM) and observed the disruption of the anterior-posterior axis and several morphological malformations in the developing brain that were both prevented by pre-exposure (2 hpf) and rescued by post-exposure (10 hpf) with FA. By whole-mount in situ hybridization with riboprobes for genes that are crucial during the early phases of neurodevelopment (ntl, pax2a, ngn1, neurod1) and by in vivo visualization of the transgenic Tg(ngn1:EGFP) zebrafish line, we found that DTG induced severe neurodevelopmental defects over time in most regions of the nervous system (notochord, midbrain-hindbrain boundary, eye, forebrain, midbrain, hindbrain, spinal cord) that were mostly but not completely rescued by FA supplementation. Of note, we observed the disruption of ngn1 expression in the dopaminergic regions of the developing forebrain, spinal cord neurons and spinal motor neuron projections, with the depletion of the tyrosine hydroxylase (TH)+ dopaminergic neurons of the dorsal diencephalon and the strong reduction in larvae locomotion. Our study further supports previous evidence that DTG can interfere with FA pathways in the developing brain but also provides new insights regarding the mechanisms involved in the increased risk of DTG-associated fetal neurodevelopmental defects and adverse neurologic outcomes in in utero exposed children, suggesting the impairment of dopaminergic pathways.

Compassionate Use of Remdesivir for Patients with Severe Covid-19.

BACKGROUND: Remdesivir, a nucleotide analogue prodrug that inhibits viral RNA polymerases, has shown in vitro activity against SARS-CoV-2. METHODS: We provided remdesivir on a compassionate-use basis to patients hospitalized with Covid-19, the illness caused by infection with SARS-CoV-2. Patients were those with confirmed SARS-CoV-2 infection who had an oxygen saturation of 94% or less while they were breathing ambient air or who were receiving oxygen support. Patients received a 10-day course of remdesivir, consisting of 200 mg administered intravenously on day 1, followed by 100 mg daily for the remaining 9 days of treatment. This report is based on data from patients who received remdesivir during the period from January 25, 2020, through March 7, 2020, and have clinical data for at least 1 subsequent day. RESULTS: Of the 61 patients who received at least one dose of remdesivir, data from 8 could not be analyzed (including 7 patients with no post-treatment data and 1 with a dosing error). Of the 53 patients whose data were analyzed, 22 were in the United States, 22 in Europe or Canada, and 9 in Japan. At baseline, 30 patients (57%) were receiving mechanical ventilation and 4 (8%) were receiving extracorporeal membrane oxygenation. During a median follow-up of 18 days, 36 patients (68%) had an improvement in oxygen-support class, including 17 of 30 patients (57%) receiving mechanical ventilation who were extubated. A total of 25 patients (47%) were discharged, and 7 patients (13%) died; mortality was 18% (6 of 34) among patients receiving invasive ventilation and 5% (1 of 19) among those not receiving invasive ventilation. CONCLUSIONS: In this cohort of patients hospitalized for severe Covid-19 who were treated with compassionate-use remdesivir, clinical improvement was observed in 36 of 53 patients (68%). Measurement of efficacy will require ongoing randomized, placebo-controlled trials of remdesivir therapy. (Funded by Gilead Sciences.).

Is HCV elimination among persons living with HIV feasible? Data from the NoCo study in the setting of the ICONA cohort.

BACKGROUND AND AIMS: Whether the HCV test-and-treat strategy impacted on the rate of new HCV infections among PLWH in Italy is unknown. METHODS: Prospective study of PLWH in the ICONA network. At baseline, PLWH were tested for HCV-Ab; HCV-RNA (if HCV-Ab positive) and, if positive, treated with DAA. SVR12 indicated eradication. Seroconversions and re-infections were evaluated yearly in HCV-Ab neg and HCV-RNA neg at first screening. We estimated the following: HCV seroconversions, incidence of HCV reinfections, and access to DAA and SVR12 rates tighter with factors associated with each outcome. Data were analysed by Cox regression, Poisson regression and logistic regression models. RESULTS: Sixteen thousand seven hundred and forty-three PLWH were included; 27.3% HCV-Ab positive; of these, 39.3% HCV-RNA positive. HCV seroconversion incidence: .48/100 PYFU (95% CI: .36-.65); re-infections incidence: 1.40/100 PYFU (95% CI: .91-2.04). The risk factor for HCV re-infection was young age: aIRR 1.85, 95% CI: 1.17-2.95) per 10 years younger. 86.4% of HCV viremic in follow-up started DAA. PWID vs. heterosexuals (aHR .75, 95% CI .62-.90), HIV-RNA >50 copies/mL (aHR .70, 95% CI .56-.87), HCV genotype other than G1, G2, G3, G4 or with multiple/missing HCV genotype and post-COVID-19 calendar periods were associated with lower DAA access. 922/965 (95.5%) PLWH achieved SVR12. We estimated 72% reduction of chance to achieve SVR12 in PLWH with a CD4 count <200/mm3 (vs. CD4 ≥200/mm3 aOR .18, 95% CI: .07-.46). 95.5% of DAA-treated individuals eradicated HCV, but they represent only 53.2% of HCV viremic PLWH and 66.4% of those in follow-up. HCV-RNA positivity by year decreased from 41.7% in 2017 to 11.7% in 2022. CONCLUSIONS: The screening-and-treat campaign implemented in Italy, even if only partially effective, resulted in a dramatic drop in HCV circulation in our cohort.

The impact of early therapies for COVID-19 on death, hospitalization and persisting symptoms: a retrospective study.

PURPOSE: Oral antivirals (nirmatrelvir/ritonavir and molnupiravir), intravenous short treatment of remdesivir and anti-SARS-CoV-2 monoclonal antibodies (mAbs) have been used for early COVID-19 treatments in high risk of disease progression patients. The term long COVID has been used to refer to a range of new, returning, or ongoing symptoms after SARS-CoV-2 infection. Little is known about the impact of such therapies on long COVID. METHODS: This is a retrospective observational study, including all outpatients evaluated from April 2021 to March 2022 in Brescia, Lombardy, northern Italy. Patients were stratified in three groups: (a) treated with mAbs, (b) treated with antivirals drugs and (c) controls (patients eligible for a or b who refused treatment). Data were collected at baseline and at month 1 and 3 (data on self-reported symptoms were collected using a telephone-administered questionnaire). We assessed early COVID-19 therapies effectiveness in preventing hospitalization, death at 1 or 3 months and persisting symptoms at 3 months after the onset of SARS-CoV-2 infection. RESULTS: A total of 649 patients were included in the study, of which 242 (37.3%) were treated with mAbs, 197 (30.3%) with antiviral drugs and 210 (32.4%) were not treated. Patients most frequently reported cerebro-cardiovascular diseases (36.7%) followed by obesity (22%). Overall, 29 patients (4.5%) died or were hospitalized at 1 or 3-month follow-up. Death or hospitalization was positively associated with older ages, with a significant linear trend (OR 3.05; 95% CI 1.16-8.06, for patients aged 80 or more years compared to those aged less than 65). Data on long COVID at 3 months were available for 323 (49.8%) patients. A positive association emerged for females compared to men, with an OR of 2.14 (95% CI 1.30-3.53) for any symptoms. Conversely, inverse associations were found for treatment groups as compared to the control one, with significant estimates among patients treated with antiviral drugs for any symptoms (OR 0.43, 95% CI 0.21-0.87) and patients treated with mAbs for any neuro-behavioral symptoms (OR 0.48, 95% CI 0.25-0.92). CONCLUSIONS: We report beneficial effect of early use of anti-SARS-CoV-2 antivirals and mAbs on long COVID.

Does the rapid initiation of antiretroviral therapy at HIV diagnosis impact virological response in a real-life setting? A single-centre experience in Northern Italy.

Rapid initiation of antiretroviral therapy (ART) has been proven efficacious and safe, but more investigations are needed to define feasibility of rapid ART approach in real-life settings.We conducted a retrospective, observational study on newly HIVdiagnosed patients referred to our Infectious Diseases Department from September 1st, 2015, to July 31st, 2019. According to the timing of ART initiation, we distinguished 3 groups of patients (rapid, intermediate and late group) and represented the trend of virological response during a 400-days-period. The hazard ratios of each predictor on viral suppression were estimated through the Cox proportional hazard model.The median time from HIV diagnosis to the first medical referral was 15 days and the median time from the first care access to therapy start was 24 days. Among patients, 37.6% started ART within 7 days, 20.6% between 8 and 30 days, and 41.8% after 30 days. Longer time to ART start and higher baseline viral load were associated with a lower probability of viral suppression. After one year, all groups showed a high viral suppression rate (99%). In a high-income setting the rapid ART approach seems useful to accelerate viral suppression which is great over time regardless of ART initiation timing.

Cabotegravir Exposure of Zebrafish (Danio rerio) Embryos Impacts on Neurodevelopment and Behavior.

As most new medications, Cabotegravir (CAB) was recently approved as an antiretroviral treatment of HIV infection without in-depth safety information on in utero exposure. Although no developmental toxicity in rats and rabbits was reported, recent studies demonstrated that CAB decreases pluripotency of human embryonic stem cells. CAB exposure effects during development were assessed in zebrafish embryos by the Fish Embryo Toxicity test after exposure at subtherapeutic concentrations up to 25× the human Cmax. Larvae behavior was assessed by the light-dark locomotion test. The expression of factors involved in neurogenesis was evaluated by whole-mount in situ hybridization. CAB did not cause gross morphological defects at low doses, although pericardial edema, uninflated swim bladder, decreased heartbeats, growth delay, and decreased hatching rate were observed at the highest concentrations. Decreased locomotion was observed even at the subtherapeutic dose, suggesting alterations of nervous system integrity. This hypothesis was supported by the observation of decreased expression of crucial factors involved in early neuronal differentiation in diencephalic and telencephalic dopaminergic areas, midbrain/hindbrain boundary, and craniofacial ganglia. These findings support CAB effects on neurogenesis in zebrafish embryos and suggest long-term follow-up of exposed infants to provide data on drug safety during pregnancy.

Comparison of Efavirenz and Doravirine Developmental Toxicity in an Embryo Animal Model.

In the past, one of the most widely used non-nucleoside reverse transcriptase inhibitors (NNRTI) in first-line antiretroviral therapy (ART) of HIV infection was efavirenz (EFV), which is already used as a cost-effective treatment in developing countries due to its efficacy, tolerability, and availability. However, EFV also demonstrates several adverse effects, like hepatotoxicity, altered lipid profile, neuropsychological symptoms, and behavioral effects in children after in utero exposure. In 2018, another NNRTI, doravirine (DOR), was approved due to its similar efficacy but better safety profile. Preclinical safety studies demonstrated that DOR is not genotoxic and exhibits no developmental toxicity or effects on fertility in rats. Zebrafish (Danio rerio) embryos have been widely accepted as a vertebrate model for pharmacological and developmental studies. We used zebrafish embryos as an in vivo model to investigate the developmental toxicity of DOR compared to EFV. After exposure of the embryos to the drugs from the gastrula stage up to different developmental stages (30 embryos for each arm, in three independent experiments), we assessed their survival, morphology, hatching rate, apoptosis in the developing head, locomotion behavior, vasculature development, and neutral lipid distribution. Overall, DOR showed a better safety profile than EFV in our model. Therapeutic and supra-therapeutic doses of DOR induced very low mortality [survival rates: 92, 90, 88, 88, and 81% at 1, 5, 10, 25, and 50 µM, respectively, at 24 h post fecundation (hpf), and 88, 85, 88, 89, and 75% at the same doses, respectively, at 48 hpf] and mild morphological alterations compared to EFV exposure also in the sub-therapeutic ranges (survival rates: 80, 77, 69, 63, and 44% at 1, 5, 10, 25, and 50 µM, respectively, at 24 hpf and 72, 70, 63, 52, and 0% at the same doses, respectively, at 48 hpf). Further, DOR only slightly affected the hatching rate at supra-therapeutic doses (97, 98, 96, 87, and 83% at 1, 5, 10, 25, and 50 µM, respectively, at 72 hpf), while EFV already strongly reduced hatching at sub-therapeutic doses (83, 49, 11, 0, and 0% at 1, 5, 10, 25, and 50 µM, respectively, at the same time endpoint). Both DOR at therapeutic doses and most severely EFV at sub-therapeutic doses enhanced apoptosis in the developing head during crucial phases of embryo neurodevelopment and perturbed the locomotor behavior. Furthermore, EFV strongly affected angiogenesis and disturbed neutral lipid homeostasis even at sub-therapeutic doses compared to DOR at therapeutic concentrations. Our findings in zebrafish embryos add further data confirming the higher safety of DOR with respect to EFV regarding embryo development, neurogenesis, angiogenesis, and lipid metabolism. Further studies are needed to explore the molecular mechanisms underlying the better pharmacological safety profile of DOR, and further human studies are required to confirm these results in the zebrafish animal model.

Psychological and Emotional Impact of COVID-19 Pandemic on People Living with Chronic Disease: HIV and Cancer.

People living with chronic disease (PLWCD) are the frailest category, both for the risk of severe COVID-19 illness and for the impact on the care continuum. Aim of this study was to analyze coping strategies and resilience in people living with HIV (PLWH) compared to people living with oncological diseases (PLWOD) during COVID-19 pandemic. We administrated an anonymous questionnaire, which explored the emotional experience, the demographic factors linked to a COVID-19-related stress syndrome, the patient's perception about the adequacy of clinical undertaking from the hospital and the resilience. We analyzed 324 questionnaires. There were no significant differences in prevalence of psychological distress among the whole cohort; however, PLWOD were calmer, less troubled, and more serene than PLWH. Moreover, PLWH smoked more, ate more, and gained more weight than PLWOD. Most patients didn't feel lonely and continued to take pleasure from their activities. No differences in resilience were found between the groups. In the whole cohort lower levels of resilience were found in patients that were unemployed, with history of psychological disorders and in those who experienced more feelings of anger, anxiety and concern. In our study, patients seemed to preserve their well-being, and to activate adaptive coping during the pandemic.

An exploratory pilot study on the involvement of APOE, HFE, C9ORF72 variants and comorbidities in neurocognitive and physical performance in a group of HIV-infected people.

Cognitive decline of aging is modulated by chronic inflammation and comorbidities. In people with HIV-infection (PWH) it may also be affected by HIV-induced inflammation, lifestyle and long-term effects of antiretroviral therapies (ART). The role of genetics in the susceptibility to HIV-associated neurocognitive disorders (HAND) is not fully understood. Here we explored the possible relations among variants in 3 genes involved in inflammation and neurodegenerative disorders (APOE: ε2/ε3/ε4; HFE: H63D; C9ORF72: hexanucleotide expansions ≥ 9 repeats), cognitive/functional impairment (MiniMental State Examination MMSE, Clock Drawing Test CDT, Short Physical Performance Battery SPPB), comorbidities and HIV-related variables in a cohort of > 50 years old PWH (n = 60) with at least 10 years efficient ART. Patients with diabetes or hypertension showed significantly lower MMSE (p = .031) or SPPB (p = .010) scores, respectively, while no relations between HIV-related variables and cognitive/functional scores were observed. Patients with at least one APOEε3 allele had higher CDT scores (p = .019), APOEε2/ε4 patients showing the lowest scores in all tests. Patients with HFE-H63D variant showed more frequently hypertriglyceridemia (p = .023) and those harboring C9ORF72 expansions > 9 repeats had higher CD4+-cell counts (p = .032) and CD4% (p = .041). Multiple linear regression analysis computed to verify possible associations among cognitive/functional scores and all variables further suggested positive association between higher CDT scores and the presence of at least one APOEε3 allele (2,2; 95% CI [0,03 0,8]; p = .037), independent of other variables, although the model did not reach the statistical significance (p = .14). These data suggest that in PWH on efficient ART cognitive abilities and physical performances may be partly associated with comorbidities and genetic background. However, further analyses are needed to establish whether they could be also dependent and influenced by comorbidities and genetic background.

Antibody responses to the SARS-CoV-2 vaccine in individuals with various inborn errors of immunity.

BACKGROUND: SARS-CoV-2 vaccination is recommended in patients with inborn errors of immunity (IEIs); however, little is known about immunogenicity and safety in these patients. OBJECTIVE: We sought to evaluate the impact of genetic diagnosis, age, and treatment on antibody response to COVID-19 vaccine and related adverse events in a cohort of patients with IEIs. METHODS: Plasma was collected from 22 health care worker controls, 81 patients with IEIs, and 2 patients with thymoma; the plasma was collected before immunization, 1 to 6 days before the second dose of mRNA vaccine, and at a median of 30 days after completion of the immunization schedule with either mRNA vaccine or a single dose of Johnson & Johnson's Janssen vaccine. Anti-spike (anti-S) and anti-nucleocapsid antibody titers were measured by using a luciferase immunoprecipitation systems method. Information on T- and B-cell counts and use of immunosuppressive drugs was extracted from medical records, and information on vaccine-associated adverse events was collected after each dose. RESULTS: Anti-S antibodies were detected in 27 of 46 patients (58.7%) after 1 dose of mRNA vaccine and in 63 of 74 fully immunized patients (85.1%). A lower rate of seroconversion (7 of 11 [63.6%]) was observed in patients with autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy. Previous use of rituximab and baseline counts of less than 1000 CD3+ T cells/mL and less than 100 CD19+ B cells/mL were associated with lower anti-S IgG levels. No significant adverse events were reported. CONCLUSION: Vaccinating patients with IEIs is safe, but immunogenicity is affected by certain therapies and gene defects. These data may guide the counseling of patients with IEIs regarding prevention of SARS-CoV-2 infection and the need for subsequent boosts.

Omicron Genetic and Clinical Peculiarities That May Overturn SARS-CoV-2 Pandemic: A Literature Review.

The Coronavirus disease 2019 (COVID-19) pandemic poses a great threat to global public health. The original wild-type strain of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has genetically evolved, and several variants of concern (VOC) have emerged. On 26 November 2021, a new variant named Omicron (B.1.1.529) was designated as the fifth VOC, revealing that SARS-CoV-2 has the potential to go beyond the available therapies. The high number of mutations harboured on the spike protein make Omicron highly transmissible, less responsive to several of the currently used drugs, as well as potentially able to escape immune protection elicited by both vaccines and previous infection. We reviewed the latest publication and the most recent available literature on the Omicron variant, enlightening both reasons for concern and high hopes for new therapeutic strategies.

Omicron BA.2 Lineage, the "Stealth" Variant: Is It Truly a Silent Epidemic? A Literature Review.

The epidemic curve of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is silently rising again. Worldwide, the dominant SARS-CoV-2 variant of concern (VOC) is Omicron, and its virological characteristics, such as transmissibility, pathogenicity, and resistance to both vaccine- and infection-induced immunity as well as antiviral drugs, are an urgent public health concern. The Omicron variant has five major sub-lineages; as of February 2022, the BA.2 lineage has been detected in several European and Asian countries, becoming the predominant variant and the real antagonist of the ongoing surge. Hence, although global attention is currently focused on dramatic, historically significant events and the multi-country monkeypox outbreak, this new epidemic is unlikely to fade away in silence. Many aspects of this lineage are still unclear and controversial, but its apparent replication advantage and higher transmissibility, as well as its ability to escape neutralizing antibodies induced by vaccination and previous infection, are rising global concerns. Herein, we review the latest publications and the most recent available literature on the BA.2 lineage of the Omicron variant.

CD4/CD8 Ratio and the Risk of Kaposi Sarcoma or Non-Hodgkin Lymphoma in the Context of Efficiently Treated Human Immunodeficiency Virus (HIV) Infection: A Collaborative Analysis of 20 European Cohort Studies.

BACKGROUND: A persistently low CD4/CD8 ratio has been reported to inversely correlate with the risk of non-AIDS defining cancer in people living with human immunodeficiency virus (HIV; PLWH) efficiently treated by combination antiretroviral therapy (cART). We evaluated the impact of the CD4/CD8 ratio on the risk of Kaposi sarcoma (KS) or non-Hodgkin lymphoma (NHL), still among the most frequent cancers in treated PLWH. METHODS: PLWH from the Collaboration of Observational HIV Epidemiological Research Europe (COHERE) were included if they achieved virological control (viral load ≤ 500 copies/mL) within 9 months following cART and without previous KS/LNH diagnosis. Cox models were used to identify factors associated with KS or NHL risk, in all participants and those with CD4 ≥ 500/mm3 at virological control. We analyzed the CD4/CD8 ratio, CD4 count and CD8 count as time-dependent variables, using spline transformations. RESULTS: We included 56 708 PLWH, enrolled between 2000 and 2014. At virological control, the median (interquartile range [IQR]) CD4 count, CD8 count, and CD4/CD8 ratio were 414 (296-552)/mm3, 936 (670-1304)/mm3, and 0.43 (0.28-0.65), respectively. Overall, 221 KS and 187 NHL were diagnosed 9 (2-37) and 18 (7-42) months after virological control. Low CD4/CD8 ratios were associated with KS risk (hazard ratio [HR] = 2.02 [95% confidence interval {CI } = 1.23-3.31]) when comparing CD4/CD8 = 0.3 to CD4/CD8 = 1) but not with NHL risk. High CD8 counts were associated with higher NHL risk (HR = 3.14 [95% CI = 1.58-6.22]) when comparing CD8 = 3000/mm3 to CD8 = 1000/mm3). Similar results with increased associations were found in PLWH with CD4 ≥ 500/mm3 at virological control (HR = 3.27 [95% CI = 1.60-6.56] for KS; HR = 5.28 [95% CI = 2.17-12.83] for NHL). CONCLUSIONS: Low CD4/CD8 ratios and high CD8 counts despite effective cART were associated with increased KS/NHL risks respectively, especially when CD4 ≥ 500/mm3.

Immune response in children with COVID-19 is characterized by lower levels of T-cell activation than infected adults.

Study of immunological features of immune response in 14 children (aged from 12 days up to 15 years) and of 10 adults who developed COVID-19 show increased number of activated CD4 and CD8 cells expressing DR and higher plasmatic levels of IL-12 and IL-1ß in adults with COVID-19, but not in children. In addition, plasmatic levels of CCL5/RANTES are higher in children and adults with COVID-19, while CXCL9/MIG was only increased in adults. Higher number of activated T cells and expression of IL-12 and CXCL9 suggest prominent Th1 polarization of immune response against SARS-CoV2 in infected adults as compared with children.

The impact of DAA-mediated HCV eradication on CD4+ and CD8+ T lymphocyte trajectories in HIV/HCV coinfected patients: Data from the ICONA Foundation Cohort.

HCV infection has been hypothesized as a contributor of poor CD4+ recovery in patients living with HIV (PLWHIV). Aim of this study was to evaluate CD4+ , CD8+ cells and CD4/CD8 ratio trends before and after HCV treatment with direct acting agents (DAA) in PLWHIV. HIV/HCV patients enrolled in ICONA and HepaICONA cohorts with HIV-RNA≤50 copies/ml who achieved a sustained viral response after DAA treatment were studied. A linear regression model was used to investigate CD4+ , CD8+ and CD4/CD8 changes 12 months before and after DAA treatment. A total of 939 HIV/HCV patients were included, 225 (24.0%) female, median age: 53 years (IQR 50-56). At DAA initiation, CD4+ T cell count was <350 cells/mm3 in 164 patients (17.5%), and 246 patients (26.2%) had liver stiffness>12.5 kPa. Trends of CD4+ and CD4/CD8 ratio were similar before and after DAA in all study populations (CD4+ change +17.6 cells/mm3 (95%CI -33.5; 69.4, p = 0.494); CD4/CD8 change 0.013 (95%CI -0.061; 0.036, p = 0.611). However, patients treated with ribavirin (RBV)-free DAA showed a significant decrease in CD8+ cells (-204.3 cells/mm3 , 95%CI -375.0;-33.4, p = 0.019), while patients treated with RBV experienced CD8+ cell increase (+141.2 cells/mm3 , 95%CI 40.3; 242.1, p = 0.006). In conclusion, HCV eradication following DAA treatment does not seem to have an impact on CD4+ T cell recovery in PLWHIV. However, a fast decline of CD8+ T cells has been observed in patients treated without RBV, suggesting a favourable effect of HCV clearance on the general state of immune activation.

Descriptive modification of inflammatory markers in HIV patients after cART initiation according to gender, smoking habit, CMV infection, BMI and serum lipids.

Persistent inflammation, despite anti-retroviral therapy (ART), is an independent predictor of mortality and comorbidities in HIV infection. Multiple factors, including lifestyle and chronic viral coinfections, may contribute. Several of these factors are also associated with a chronic inflammation in the general population. Little is known about the degree to which these factors influence inflammation in HIV infection, particularly within the first year of ART. The purpose of this study was to distinguish the effects of factors (gender, body mass index, cholesterol and triglyceride levels, smoke habit and cytomegalovirus seropositivity), known to contribute to inflammation, on inflammation biomarkers over the first year of ART in HIV-infected patients. Linear mixed model analysis revealed significant biomarker decreases [soluble CD14 (s-CD14), soluble CD163 (s-CD163) and D-dimer (DD)], or increases [C Reactive Protein (CRP) and interleukin-6 (IL-6)] over time in the whole cohort, differences in most categories (genders for IL-6, smoke habit for s-CD14, cytomegalovirus infection for s-CD163 and IL-6) and in some category × time interactions [gender for interleukin-7 (IL-7)], cytomegalovirus infection for s-CD14 and cholesterol levels for s-CD14 and Tumor Necrosis Factor α (TNF-α)]. This explorative longitudinal study suggests further investigations on targeting inflammation pathophysiology in HIV-infected patients on ART.