The Anti-SARS-CoV-2 S-Protein IgG, Which Is Detected Using the Chemiluminescence Microparticle Immunoassay (CMIA) in Individuals Having Either a History of COVID-19 Vaccination and/or SARS-CoV-2 Infection, Showed a High-Titer Neutralizing Effect.

Neutralizing antibodies plays a primary role in protective immunity by preventing severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) from entering the cells. Therefore, characterization of antiviral immunity is important for protection against SARS-CoV-2. In this study, the neutralizing effect of the anti-SARS-CoV-2 S1 protein IgG, which was detected using the chemiluminescence microparticle immunoassay (CMIA)-based SARS-CoV-2 IgG II Quant (Abbott, Waukegan, IL, USA) test in SARS-CoV-2 infected and/or vaccinated individuals, was investigated with a surrogate virus neutralization test (sVNT). In total, 120 Seropositive individuals were included in this study. They were divided into two groups: Vaccinated (n = 60) and Vaccinated + Previously Infected (n = 60). A commercial sVNT, the ACE2-RBD Neutralization Test (Dia.Pro, Milan, Italy), was used to assess the neutralizing effect. The assay is performed in two steps: screening and titration. The screening showed positive results in all seropositive samples. Low titration in 1.7%, medium titration in 5%, and high titration in 93.3% of the Vaccinated group, and medium titration in 1.7% and high titration in 98.3% of the other group, as obtained from the ACE2-RBD titration test. A strong positive and significant correlation was found between the SARS-CoV-2 IgG II Quant test and the ACE2-RBD titration test at the 1/32 titration level for both groups (p < 0.001 for both). This study shows that the SARS-CoV-2 IgG detected using the CMIA method after SARS-CoV-2 infection and/or vaccination has a high neutralizing titration by using the sVNT. In line with these data, knowledge that seropositivity determined by CMIA also indicates a strong neutralizing effect contributes to countrywide planning for protecting the population.

Distribution of Opportunistic Pathogens in People Living with HIV at a University Hospital in Istanbul over a One-Year Treatment Period and Its Association with CD4 T Cell Counts.

Among sexually transmitted diseases, HIV causes very serious clinical manifestations that can lead to death. As a result, millions of people have to live with this problem that threatens their health. The virus attacks the immune system of the host, especially CD4+ T lymphocytes, causing the suppression of the immune system. CD4, CD8 counts, and HIV RNA viral loads are monitored in HIV-infected patients with antiretroviral treatment, and CD4 counts play an important role in determining the effectiveness of the treatment. Despite the advances in treatment in the present day, opportunistic infections are the main cause of morbidity and mortality in these patients, and the evaluation of immunological parameters is valuable for the prognosis of the disease in this process. In the present study, the purpose was to investigate the opportunistic infections faced by naive HIV-positive patients who applied to our laboratory and were diagnosed between 2019 and 2022 during their one-year treatment period, and the correlation of the immunological parameters was also evaluated retrospectively using the hospital automation system and laboratory data. A total of 107 opportunistic causative microorganisms were identified in 87 of the 230 HIV-positive patients over one year. T. pallidum was detected in 43 (18.6%) of these patients, Cytomegalovirus (CMV) in 32 (13.9%), Epstein-Barr virus (EBV) in 9 (3.9%), Hepatitis B virus (HBV) in 10 (4.3%), C. albicans in 7 (3%), M. tuberculosis in 3 (1.3%), Hepatitis C virus (HCV) in 2 (0.8%), and C. glabrata in 1 (0.4%) patient. Although mono-agent co-infections were determined in 69 of 87 people living with HIV, two-agent co-infections were detected in 16 HIV patients, and three-agent co-infections were identified in two HIV patients. Considering the correlation between the CD4/CD8 ratio and infection positivity, a moderate negative correlation was determined with HIV RNA viral load and CMV infection. The CD4/CD8 ratio had a low negative correlation with EBV and C. albicans infections. It was also found that the follow-up of HIV RNA load in the diagnosis of T. pallidum, CMV, EBV, and C. albicans may be meaningful. Opportunistic infections mainly affect immunosuppressed patients and can be prevented with effective treatment. Although it is already known that HIV patients may face different infections during their treatment, it was concluded that more attention should be paid to T. pallidum, CMV, EBV, and C. albicans agents. These infections should be routinely monitored with HIV viral load and the CD4/CD8 ratio.

Comparison of the Clinical and Laboratory Findings and Outcomes of Hospitalized COVID-19 Patients Who Were Either Fully Vaccinated with Coronavac or Not: An Analytical, Cross Sectional Study.

COVID-19 vaccines are highly protective against severe disease; however, vaccine breakthrough infections resulting in hospitalization may still occur in a small percentage of vaccinated individuals. We investigated whether the clinical and microbiological features and outcomes were different between hospitalized COVID-19 patients who were either fully vaccinated with Coronovac or not. All hospitalized COVID-19 patients who had at least one dose of Coronavac were included in the study. The oldest unvaccinated patients with comorbidities, who were hospitalized during the same period, were chosen as controls. All epidemiologic, clinical and laboratory data of the patients were recorded and compared between the fully vaccinated and unvaccinated individuals. There were 69 and 217 patients who had been either fully vaccinated with Coronavac or not, respectively. All breakthrough infections occurred in the first 3 months of vaccination. Fully vaccinated patients were older and had more comorbidities than unvaccinated patients. There were minor differences between the groups in symptoms, physical and laboratory findings, anti-spike IgG positivity rate and level, the severity of COVID-19, complications, and clinical improvement rate. The mortality rate of fully vaccinated patients was higher than the mortality rate in unvaccinated patients in univariate analysis, which was attributed to the fact that vaccinated patients were older and had more comorbidities. The severity and clinical outcomes of hospitalized patients with breakthrough COVID-19 after Coronavac vaccination were similar to those of unvaccinated patients. Our findings suggest that the immune response elicited by Coronovac could be insufficient to prevent COVID-19-related severe disease and death within 3 months of vaccination among elderly people with comorbidities.

The Role of Anti-Neutrophil Antibodies in the Etiologic Classification of Childhood Neutropenia: A Cross-Sectional Study in a Tertiary Center.

Infections, drugs, malignancies, immunodeficiency, and autoimmunity may cause neutropenia. In primary autoimmune neutropenia, anti-neutrophil antibodies (ANeuA) bind to membrane antigens of neutrophils, which give rise to peripheral destruction of neutrophils. However, it is not always easy to detect these antibodies. This study aims to investigate the etiology of neutropenia, and at the same time to evaluate the immune mechanisms by ANeuA testing using granulocyte indirect immunofluorescence test. In our study, 310 neutropenic patients who were between 3 months and 18 years of age were evaluated. ANeuA screening tests were performed in 108 neutropenic patients (group 1), and these patients were divided into 2 subgroups as persistent neutropenia (group 1P, n=12) and recovered neutropenia (group 1R, n=96). Besides, a control group in the same age range was formed, consisting of 39 non-neutropenic children (group 2). ANeuA serum levels were also checked in these groups, and no statistically significant difference could be found between groups 1 and 2, or between groups 1P and 1R, regarding ANeuA levels. As a conclusion, our study was the first comprehensive research in Turkey investigating the large-scale etiology of neutropenia. Moreover, while ANeuA screening tests did not provide sufficient insight for immune neutropenia, we argue that it is not necessary for routine use and that further research in the etiology of neutropenia is required.