Prevalence and risk factors for long COVID after mild disease: A cohort study with a symptomatic control group.

Background: There is limited data on the prevalence and risk factors for long COVID and few prospective studies with appropriate control groups and adequate sample sizes. We performed a prospective study to determine the prevalence and risk factors for long COVID. Methods: We recruited individuals aged ≥15 years who were clinically suspected of having an acute SARS-CoV-2 infection from September 2020 to April 2021. We collected nasopharyngeal swabs three to five days following symptom onset for analysing using reverse transcriptase polymerase chain reaction (RT-PCR). We also collected clinical and sociodemographic characteristics from both SARS-CoV-2 positive and negative participants using structured questionnaires. We followed-up the participants via telephone interview to assess early outcomes and persistent symptoms. For COVID-19 cases, 5D-3L EuroQol questionnaire was used to assess the impact of symptoms on quality of life. Results: We followed 814 participants (412 COVID-19 positive and 402 COVID-19 negative persons). Most (n = 741/814) had mild symptoms. Both groups had similar sociodemographic and clinical characteristics, except for the hospitalization rate (15.8% in the COVID-19 positive vs 1.5% in the COVID-19 negative group). One month after disease onset, 122/412 (29.6%) individuals in the COVID-19 positive (long COVID) and 24 (6%) in the COVID-19 negative group reported residual symptoms. In the long COVID group, fatigue, olfactory disorder, and myalgia were the most frequent symptoms in the acute phase. Compared to recovered individuals, older age and having more than five symptoms during the acute phase were risk factors for long COVID. Quality of life was evaluated in 102 out of 122 cases of long COVID, with 57 (55.9%) reporting an impact in at least one dimension of the European Quality of Life 5 Dimensions 3 Level (EQ-5D-3L) questionnaire. Conclusions: In this prospective study consisting predominantly of individuals with mild disease, the persistence of symptoms after an acute respiratory illness was associated with a diagnosis of COVID-19. Polysymptomatic acute disease and older age were risk factors for long COVID.

Hemoglobin Variant Profiles among Brazilian Quilombola Communities.

Brazilian Quilombolas are communities composed of African-derived populations that have their territories guaranteed by the Brazilian Constitution. The present study investigated the hemoglobin (Hb) variants among these population groups. This study was conducted in a total of 2843 individuals of Brazilian Quilombola communities of the Bahia, Pará, and Piauí states. All the participants had their Hb profiles evaluated. The Hb S (HBB: c.20A>T) variant was described in all the studied localities. However, the individuals in Bahia State had the highest frequency of the Hb C (HBB: c.19G>A) variant; individuals from Piauí State had a higher frequency of the Hb D-Punjab (HBB: c.364G>C) variant compared to the other states, and individuals from Pará State only carried the Hb S variant. The present study revealed a specific distribution of Hb variants that could represent different waves of African influence in these Brazilian populations.

Outcome of B-Cell Acute Lymphoblastic Leukemia in Brazilian Children: Immunophenotypical, Hematological, and Clinical Evaluation.

The aim of this study is to investigate the clinical, hematological, and immunophenotypic characteristics of Brazilian children with B-cell acute lymphoblastic leukemia (B-ALL) to identify prognostic biomarkers of the disease. Thirty-three children newly diagnosed with B-ALL were followed between March 2004 and December 2009. Information about the demographic profile, diagnosis, immunophenotype, clinical manifestations, and disease outcome were gathered from the patients' medical records. Of the 33 patients with B-ALL, 18 were male and 15 female. Eighteen patients were classified as high risk; 13 as low risk, and 2 as true low risk. The frequencies of cluster of differentiation (CD)10, CD19, and CD20 antigens were 69.7%, 81.8%, and 18.2%, respectively. Six patients (18.2%) had aberrant expression of myeloid antigens. At diagnosis, patients immunopositive for CD20 had elevated white blood cell counts (P = 0.018) and lower platelet counts (P = 0.017). The 6-year overall survival was 67.5%± 3.47%. Our results demonstrate the distinct immunophenotypic and prognostic characteristics of patients with B-ALL, which can be related to the Brazilian racial admixture. Consequently, these results will most likely aid in the selection of additional prognostic markers and their use in monitoring the clinical manifestations and treatment response among B-ALL patients.

BCL11A is a major HbF quantitative trait locus in three different populations with beta-hemoglobinopathies.

Increased HbF levels or F-cell (HbF containing erythrocyte) numbers can ameliorate the disease severity of beta-thalassemia major and sickle cell anemia. Recent genome-wide association studies reported that single nucleotide polymorphisms (SNPs) in BCL11A gene on chromosome 2p16.1 were correlated with F-cells among healthy northern Europeans, and HbF among Sardinians with beta-thalassemias. In this study, we showed that SNPs in BCL11A were associated with F-cell numbers in Chinese with beta-thalassemia trait, and with HbF levels in Thais with either beta-thalassemia or HbE trait and in African Americans with sickle cell anemia. Taken together, the data suggest that the functional motifs responsible for modulating F-cells and HbF levels reside within a 3 kb region in the second intron of BCL11A.