Antibody response dynamics to CoronaVac vaccine and booster immunization in adults and the elderly: A long-term, longitudinal prospective study.

Background: The long-term humoral immune response after vaccination varies between vaccines and is dependent on the accuracy of the antibody test. A better understanding of the vaccine immune response may help to define vaccination strategies against coronavirus disease 2019 (COVID-19). Objective: To investigate the long-term immunological response to CoronaVac vaccine and determinants of breakthrough COVID-19 infection. Methods: A long-term, prospective cohort study involving vaccinated adult and elderly subjects was conducted to investigate the presence of anti-RBD-specific immunoglobulin (Ig)G, anti-nucleocapsid IgG and anti-spike trimeric protein IgG. Antibody level dynamics and risk factors associated with breakthrough COVID-19 infection were investigated. Results: In total, 3902 participants were included in this study. Vaccination with two doses of CoronaVac and a booster dose increased the levels of anti-RBD-specific IgG, anti-nucleocapsid IgG and anti-spike trimeric IgG significantly. In adults, anti-nucleocapsid IgG and anti-spike trimeric IgG levels decreased significantly 7 months after the second dose. In adults and the elderly, the levels of anti-spike trimeric IgG and anti-RBD IgG decreased significantly 4 and 6 months after the booster dose, respectively. Previous exposure to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and anti-spike trimeric IgG titres was independently associated with a lower probability of post-vaccination infection. Conclusions: A significant increase in antibody levels was found after two doses of CoronaVac and a booster dose. Antibody titres declined significantly 7 months post-vaccination in participants who did not receive a booster dose. Higher levels of antibodies and previous SARS-CoV-2 infection were associated with protection against breakthrough COVID-19.

Bioactive Lipids as Chronic Myeloid Leukemia's Potential Biomarkers for Disease Progression and Response to Tyrosine Kinase Inhibitors.

Chronic myelogenous leukemia (CML) is a myeloproliferative neoplasm that expresses the Philadelphia chromosome and constitutively activated Bcr-Abl tyrosine kinase in hematopoietic progenitor cells. Bcr-Abl tyrosine-kinase inhibitors (TKI) do not definitively cure all CML patients. The efficacy of TKI is reduced in CML patients in the blastic phase-the most severe phase of the disease-and resistance to this drug has emerged. There is limited knowledge on the underlying mechanisms of disease progression and resistance to TKI beyond BCR-ABL1, as well as on the impact of TKI treatment and disease progression on the metabolome of CML patients. The present study reports the metabolomic profiles of CML patients at different phases of the disease treated with TKI. The plasma metabolites from CML patients were analyzed using liquid chromatography, mass spectrometry, and bioinformatics. Distinct metabolic patterns were identified for CML patients at different phases of the disease and for those who were resistant to TKI. The lipid metabolism in CML patients at advanced phases and TKI-resistant patients is reprogrammed, as detected by analysis of metabolomic data. CML patients who were responsive and resistant to TKI therapy exhibited distinct enriched pathways. In addition, ceramide levels were higher and sphingomyelin levels were lower in resistant patients compared with control and CML groups. Taken together, the results here reported established metabolic profiles of CML patients who progressed to advanced phases of the disease and failed to respond to TKI therapy as well as patients in remission. In the future, an expanded study on CML metabolomics may provide new potential prognostic markers for disease progression and response to therapy.

Outcomes of HIV-associated Burkitt Lymphoma in Brazil: High treatment toxicity and refractoriness rates - A multicenter cohort study.

BACKGROUND: Although the increased use of combined antiretroviral therapy (cART) has decreased the incidence of lymphomas HIV-associated, Burkitt lymphoma (BL) incidence remains stable. Reported outcomes on HIV-associated BL from developed countries seem to corroborate that the regimens do not need to be tailored to the HIV-positive population. MATERIALS AND METHODS: This is a retrospective multicenter cohort study from Brazil, including HIV-positive patients aged 15 years and above diagnosed with BL. RESULTS: A total of 54 patients were included. Median age was 39 years (range, 15-64). At diagnosis, advanced disease was found in 86% and 52% had a CD4+ count lower than 200 cells/mm3. Five patients died before starting any regimen. Among the remaining 49 patients, most were treated with Hyper-CVAD (53%) and CODOX-M IVAC (18%). Rituximab was used in frontline in only 16% of the patients. Primary refractory disease was found in 14%. A treatment-related mortality of 38.7% and a complete response rate of 44.9% were found. At 4 years, estimated overall survival (OS) was 39.8%. All relapsed and primary refractory patients eventually died. Remaining patients died from infections (24/34), despite antimicrobial prophylaxis and associated cART. CONCLUSION: Early mortality and toxicity were higher in our cohort than in developed countries. A faster diagnosis, better understanding of the biology of the disease, establishment of low toxicity regimens, inclusion of rituximab and improvement of supportive care may decrease the mortality of HIV-associated BL in developing countries.