Weak correlation between antibody titers and neutralizing activity in sera from SARS-CoV-2 infected subjects.

Plenty of serologic tests for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been developed so far, thus documenting the importance of evaluating the relevant features of the immune response to this viral agent. The performance of these assays is currently under investigation. Amongst them, LIAISON® SARS-CoV-2 S1/S2 IgG by DiaSorin and Elecsys Anti-SARS-CoV-2 cobas® by Roche are currently used by laboratory medicine hospital departments in Italy and many other countries. In the present study, we firstly compared two serologic tests on serum samples collected at two different time points from 46 laboratory-confirmed coronavirus disease-2019 (COVID-19) subjects. Secondly, 85 negative serum samples collected before the SARS-CoV-2 pandemic were analyzed. Thirdly, possible correlations between antibody levels and the resulting neutralizing activity against a clinical isolate of SARS-CoV-2 were evaluated. Results revealed that both tests are endowed with low sensitivity on the day of hospital admission, which increased to 97.8% and 100% for samples collected after 15 days for DiaSorin and Roche tests, respectively. The specificity evaluated for the two tests ranges from 96.5% to 100%, respectively. Importantly, a poor direct correlation between antibody titers and neutralizing activity levels was evidenced in the present study. These data further shed light on both potentials and possible limitations related to SARS-CoV-2 serology. In this context, great efforts are still necessary for investigating antibody kinetics to develop novel diagnostic algorithms. Moreover, further investigations on the role of neutralizing antibodies and their correlate of protection will be of paramount importance for the development of effective vaccines.

Dynamics of HIV-1 POL antibodies after ART in chronic HIV-1 infection.

The aim of this retrospective study was to evaluate Western Blot (WB) antibody response against HIV-1 Pol proteins in people on ≥12 months of Antiretroviral Therapy (ART) and factors associated with a negative HIV-1 Pol response or with its seroreversion from positive to negative. Multivariate logistic regression models were performed to assess factors associated with a negative HIV-1 Pol or with HIV-1 Pol seroreversion. A negative HIV-1 Pol was found in 88 (16.6%) of the 530 individuals evaluated. At multivariate analysis, a negative Pol result was associated with an early ART start [adjusted odds ratio (AOR) per 3-months longer = 0.95, 95% CI=0.90-0.99] and a greater CD4+ recovery since ART start [AOR per 100-cells/µL/year higher=1.11, 95%CI=1.01-1.24]. In a subgroup of 140 patients with WB analysis performed both at HIV-1 diagnosis and after a median of 69 months, Pol seroreverted from positive to negative in 22 (15.7%) patients and was associated with a greater CD4+ recovery [AOR per 100-cells/µL/year higher =2.50 (95%CI=1.28-4.87)]. In conclusion, a negative HIV-1 Pol and a seroreversion from positive to negative were observed in more than 15% of subjects included and were associated with a better immunological profile, suggesting a lower viral exposure to the immune system over time.

Brief Report: Association Between Low HIV-1 DNA and Western Blot Reactivity to HIV-1 Pol in Chronically Infected Individuals.

BACKGROUND: The aim of the study was to evaluate whether negative HIV-1 pol on Western blot (WB) was associated with low HIV-DNA in adults with chronic HIV-1 infection and suppressive antiretroviral therapy. METHODS: Cross-sectional parent study of the APACHE trial, conducted in subjects with chronic infection, HIV-1 RNA <50 copies/mL for ≥10 years, no residual viremia for ≥5 years and CD4 >500 cells/µL screened for HIV-1 DNA. HIV-1 DNA was quantified in peripheral blood mononuclear cells (PBMCs) by real-time polymerase chain reaction and HIV-1 serostatus was tested by HIV Blot 2.2 WB assay. Multivariate logistic regression was used to determine factors associated with low HIV-1 DNA. RESULTS: We evaluated 96 patients: 78 (81%) and 18 (19%) subjects with HIV-1 DNA ≥100 copies/10 PBMCs and with HIV-1 DNA <100 copies/10 PBMCs, respectively. Median age was 32.5 (25.3-38.9), and 61 (64%) were men; moreover, we reported that nadir CD4 was 253 (167-339) cells/µL and HIV-RNA <50 copies/mL for 11.7 (10.6-14.0) years. At multivariate analysis, higher nadir CD4 [adjusted odds ratio (AOR) [95% confidence interval (CI) 1.35 (95% CI: 1.03 to 1.76), P = 0.029], longer years of HIV-1 RNA <50 copies/mL [AOR (95% CI) 2.98 (95% CI: 1.25 to 7.10), P = 0.014], a R5-tropic virus [AOR (R5 vs. non-R5) 0.20 (95% CI: 0.04 to 0.96), P = 0.044], and negative HIV-1 pol [AOR 6.59 (95% CI: 1.47 to 29.54), P = 0.014] were associated with low HIV-1 DNA. CONCLUSIONS: In patients with chronic HIV-1 infection and suppressive antiretroviral therapy, negative HIV-1 pol on WB was associated with low HIV-1 DNA as well as higher nadir CD4, longer years of HIV-1 RNA <50 copies/mL, and a R5-tropic virus.

Presence of multiple genotypes in subjects with HPV-16 infection is highly associated with anal squamous intraepithelial lesions in HIV-1 infected males.

OBJECTIVES: The aim of the study was to determine the prevalence of abnormal cytological findings, high risk (HR)-HPV genotypes and to identify factors associated with an abnormal cytological findings in a cohort of HIV-infected males. PATIENTS AND METHODS: Retrospective observational study on HIV-infected male patients who performed screening in the absence of clinical symptoms. Cytological abnormalities were classified as atypical squamous cells of undetermined significance (ASC-US), low-grade(LSIL) or high high-grade squamous intraepithelial lesion (HSIL). Logistic regression models were used to identify predictors of having LSIL/HSIL. RESULTS: Among 875 pts, abnormal cytology findings were observed in 254 (29%, 95% CI: 26.1%-32.1%) subjects: 142 (16%) had LSIL and 49 (6%) HSIL. Overall, 581 (66%, 95%CI: 63.2%-69.5%) subjects had ≥1 HR-HPV type and 269 (31%) had ≥2 HR HPV types. Multivariate logistic regression showed that subjects with multiple HR-HPV genotypes (OR = 1.351, 95%CI: 1.005-2.111) and with HPV-16 type (OR = 2.032, 95%CI: 1.313-3.146) were more likely to have LSIL/HSIL in addition to a lower CD4+/CD8+ ratio, a previous diagnosis of syphilis and a positive viral load. In another multivariate model, the presence of multiple HPV types in subjects with HPV-16 type was associated with the highest adjusted OR of having a LSIL/HSIL (OR = 2.598, 95%CI: 1.460-4.624). CONCLUSIONS: In HIV-infected men, the prevalence of abnormal cytological findings was of 29% and of HR-HPV was 66%. The concomitant presence of HPV-16 and multiple HR genotypes was associated with an increased risk of abnormal cytological findings. These data highlight the importance of screening multiple HPV genotypes in HIV-infected patients.

Human Herpesvirus 6 Infection Following Haploidentical Transplantation: Immune Recovery and Outcome.

Human herpesvirus 6 (HHV-6) is increasingly recognized as a potentially life-threatening pathogen in allogeneic hematopoietic stem cell transplantation (alloSCT). We retrospectively evaluated 54 adult patients who developed positivity to HHV-6 after alloSCT. The median time from alloSCT to HHV-6 reactivation was 34 days. HHV-6 was present in plasma samples from 31 patients, in bone marrow (BM) of 9 patients, in bronchoalveolar lavage fluid and liver or gut biopsy specimens from 33 patients, and in cerebrospinal fluid of 7 patients. Twenty-nine patients developed acute graft-versus-host disease (GVHD), mainly grade III-IV, and 15 had concomitant cytomegalovirus reactivation. The median absolute CD3+ lymphocyte count was 207 cells/µL. We reported the following clinical manifestations: fever in 43 patients, skin rash in 22, hepatitis in 19, diarrhea in 24, encephalitis in 10, BM suppression in 18, and delayed engraftment in 11. Antiviral pharmacologic treatment was administered to 37 patients; nonetheless, the mortality rate was relatively high in this population (overall survival [OS] at 1 year, 38% ± 7%). A better OS was significantly associated with a CD3+ cell count ≥200/µL at the time of HHV-6 reactivation (P = .0002). OS was also positively affected by the absence of acute GVHD grade III-IV (P = .03) and by complete disease remission (P = .03), but was not significantly influenced by steroid administration, time after alloSCT, type of antiviral prophylaxis, plasma viral load, or organ involvement. Although HHV-6 detection typically occurred early after alloSCT, better T cell immune reconstitution seems to have the potential to improve clinical outcomes. Our findings provide new insight into the interplay between HHV-6 and the transplanted immune system.

Comparison of the artus HIV-1 QS-RGQ and VERSANT HIV-1 RNA 1.0 assays for quantitative detection of human immunodeficiency virus type 1 in plasma samples.

Several integrated diagnostic platforms to quantify human immunodeficiency virus type-1 viremia have been developed in recent years. We evaluated the performances of the Artus HIV-1 QS-RGQ assay, using the complete QIAsymphony RGQ workflow. 192 clinical plasma specimens and external control panel samples were analyzed, using the Artus assay and the routine Siemens VERSANT HIV-1 RNA 1.0 assay. Three samples were excluded due to amplification inhibition. Among the remaining 189 specimens, 130 samples were detected as positive (above the limit of detection by both assays; median log10 difference: 0.01) and 18 samples were detected as negative. Eight samples (4.2%), all slightly above the limit of detection of the Versant assay, were negative with the Artus assay. The remaining 33 samples (beside 3 negative by Artus assay) were positive by both assays, but below the limit of detection at least in one of them. Results from the external panel samples showed a mean Log10 variation of -0.18 and -0.45 for the Versant and the Artus assays, respectively. As both assays showed highly correlated results, the QIAsymphony RGQ system, using the Artus HIV-1 QS-RGQ assay, could be considered a potential platform for HIV-1 RNA quantification in plasma.

Human papillomavirus infections: new perspectives for prevention and treatment.

Human papillomaviruses (HPVs) have been recognized as the main etiologic agent of cervical cancer and other anogenital neoplasms, and a leading cause of death from cancer worldwide. In the last twenty years, extensive research has contributed to document the molecular mechanisms of virus persistence and malignant transformation, confirming a direct role of viral proteins in these processes. A clear understanding of the molecular epidemiology of HPVs and the availability of powerful molecular diagnostic techniques have provided the background for prevention strategies of HPV-related carcinomas. Since these viruses are highly prevalent in the general population, strict screening programs are still necessary. Recently, major breakthroughs have emerged from immunological studies. Indeed, these studies have paved the way for medical treatment of HPV infections and provided the first highly effective preventive vaccines. For these principal reasons, the time has come for a great effort towards the eradication of these important human pathogens. The present review summarizes the main aspects of the virology, molecular epidemiology and molecular biology of HPV infection and highlights the recent perspectives of prevention and treatment of the HPV-related disease.