RESUMO
COVID-19 is a pandemic caused by SARS-CoV-2. In Chile, half a million people have been infected and more than 16,000 have died from COVID-19. As part of the clinical trial NCT04384588, we quantified IgG against S1-RBD of SARS-CoV-2 (anti-RBD) in recovered people in Santiago and evaluated their suitability as COVID-19 convalescent plasma donors. ELISA and a luminescent SARS-CoV-2 pseudotype were used for IgG and neutralizing antibody quantification. 72.9% of the convalescent population (468 of 639) showed seroconversion (5-55 µg/mL anti-RBD IgG) and were suitable candidates for plasma donation. Analysis by gender, age, and days after symptom offset did not show significant differences. Neutralizing activity correlated with an increased concentration of anti-RBD IgG (p < 0.0001) and showed a high variability between donors. We confirmed that the majority of the Chilean patients have developed anti-SARS-CoV-2 antibodies. The quantification of anti-RBD IgG in convalescent plasma donors is necessary to increase the detection of neutralizing antibodies.
Assuntos
COVID-19/imunologia , COVID-19/terapia , SARS-CoV-2/fisiologia , Glicoproteína da Espícula de Coronavírus/imunologia , Adolescente , Adulto , Anticorpos Neutralizantes/sangue , Anticorpos Neutralizantes/uso terapêutico , Anticorpos Antivirais/sangue , Anticorpos Antivirais/uso terapêutico , Chile , Feminino , Humanos , Imunização Passiva/métodos , Imunoglobulina G/sangue , Masculino , Pessoa de Meia-Idade , Pandemias , Soroconversão , Adulto Jovem , Soroterapia para COVID-19RESUMO
Hyperleukocytic leukemias are a small proportion of leukemias that have white blood cell count > 100 x 10(9)/l, most of them are leukemic blast cells. These leukemias have a grave prognosis because they can develop a leukostasis syndrome which describes: the acute onset of pulmonary failure and, often, neurologic deficits and disseminated intravascular coagulation (DIC). The leukostasis is produced by the mechanical obstruction of vascular bed by blast cells, which can be induced by the spontaneous tumor lysis or as a side effect of cytotoxic drugs. So, hyperleukocytic leukemias require early and vigorous measures to decrease the white blood cell count, using leukapheresis and/or chemotherapy, before pulmonary failure exists. Then, it is possible to reverse the lesions. We report two cases of acute myeloblastic leukemia with a white blood count > 100 x 10(9)/l, that developed a respiratory distress syndrome and died. The postmortem examination has been done in one of the cases.
