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Introduction: With the arrival of the SARS-CoV-2 (Coronavirus 2 of severe acute respiratory syndrome) pandemic in Brazil, especially in the city of São Paulo, there was a need to apply social isolation policies associated with testing, covering all municipalities. The Clinical Analysis Laboratory of Centro Universitário FMABC was one of the first laboratories to receive certification and qualification to perform RT-PCR (reverse transcriptase reaction followed by polymerase chain reaction) tests in the metropolitan region of São Paulo. Objective: Aim to analyze the influence of adopting social isolation on the incidence of positivity in COVID-19 tests in the metropolitan region of São Paulo, Brazil. Methods: a descriptive study carried out from March to May 2020, epidemiological data were collected from each unit served and organized by the data controllership team of the Clinical Analysis Laboratory of FMABC. Epidemiological, demographic, and laboratory data were extracted from the Matrix® outpatient data management system. Clinically suspected cases and confirmed by laboratory tests (RT-PCR and serological tests) were entered. The tests were divided into serological tests using the RT-PCR molecular test, on samples of nasopharyngeal mucosal scrapings collected with sterile Swab. Results: It were evaluated PCR test and antibody presence (IgA, IgM and IgG) in blood samples of 16.297 patients. 22.718 tests were performed for the diagnosis of COVID-19, both RT-PCR (10.410 tests) and serological tests to detect anti-SARS-CoV-2 antibodies, IgA, IgM and IgG, a total of 16.297 patients were assessed, 63% women and 37% men. It was observed that the social isolation policies adopted during this period contained the massive expansion of contamination, at least while the social isolation rates were above 55%. Conclusion: The data of this study demonstrated the effectiveness of social isolation in containing the positive contamination of SARS-CoV-2 in the metropolitan region of São Paulo, at least for the first three months.

Patients with COVID-19 who progressed to a more advanced stage of the disease were observed to develop coagulation disorders. Mutations in genes encoding clotting factors, such as Prothrombin Factor II, Leiden Factor V and MTHFR are associated with the development of thromboembolism. The aim of this study was to determine the prevalence of genetic variants present in these genes in patients with COVID-19, and to associate their presence with disease severity and D-dimer values. 405 patients with different manifestations of COVID-19 were genotyped by qPCR; genotypes were associated with disease severity and D-dimer values. A slightly prevalence of the FVL mutated allele in the group with positive diagnosis was found; also, higher levels of D-dimer in patients who required treatment in intensive care were observed. Individuals with hereditary thrombophilia are at greater risk of developing a thrombolytic event after infection (long-term COVID). Our data show the benefits of performing genetic screening for hereditary thrombophilia in individuals infected with SARS-Cov-2 in order to establish, together with classical laboratory parameters, a risk factor for the development of thrombosis both during the infectious process and for post-COVID and thus avoid a vascular event.

Objective: To investigate possible differences between laboratory profiles of symptomatic and asymptomatic patients. There are different of them available for COVID-19 diagnoses and surveillance, so this research was to evaluate the positive agreement the diagnostic methods. Methods: For symptomatic patients swab samples from nasal and oral mucosal were collected between first and second week after symptoms onset, to perform RT-PCR, blood samples were collected 7 days after to perform antibody detection test. For asymptomatic patients, only antibody detection was performed to confirm the infection. We investigated specific humoral immune response for symptomatic and asymptomatic patients and also analyzed the positivity index and kappa agreement between immunochromatographic and ELISA assays. Results: Most symptomatic patients presented negative RT-PCR with IgM and IgA detection. Symptomatic and asymptomatic patients have presented elevated IgM and IgA immunoglobulins, being this detection higher in symptomatic patients. The positivity index for immunochromatographic was higher than ELISA and there was no kappa agreement between IgM and IgA detection between these two methods. Conclusion: Symptomatic patients presented higher amounts of IgM and IgA than asymptomatic, suggesting a relation between antibody quantity and severity of disease. We verified no agreement between IgM and IgA detection, and observed higher positivity index for IMMUNO when compared to ELISA. The different kinetics may cause a variation in their detection. Also, many different virus proteins can be used as antigens in these methods, being able of altering their sensibility and specificity.

Background: The 6-mercaptopurine is an active ingredient used to treat certain types of leukemia. This drug is an immunosuppressive and antineoplastic agent that belongs to the thiopurine class. In Brazil, 6-MP is currently available only in the form of 50 mg tablets, sold as Purinethol® and manufactured by Glaxo Smith Kline. The lack of the liquid formulation’s production impedes treatment, assuming that one of its advantages go through its applicability in pediatric patients, which shows the highest incidence among others. Objective: The purpose of this work was to evaluate the development and application of a reverse phase high performance liquid chromatography (HPLC) method using an Agilent 1220 Infinity® G4294B chromatograph with photodiode array detector. Methods: HPLC assays were performed on an Eclipse plus® C18 column (4.6 x 150 mm, 3.5 µm particle size) using a gradient mode mixture of acetonitrile and aqueous acetic acid solution as a mobile phase, with a flow of 1 mL.min-1 and detection at 324 nm. The method was validated by determining its selectivity, linearity, precision, accuracy, and robustness. Results: Retention time for 6-mercaptopurine was 5.12 minutes. The detector’s response was linear at concentrations from 1.6 to 2.4 µg/mL. The results of the method’s accuracy evaluation of the accuracy showed with mean recovery of the amount of substance added to the samples of between 99.88 and 100.5%. For precision, repeatability and intermediate precision were evaluated. The repeatability showed standard deviation of 0.0737. The intermediate precision was assessed on three different. For the three days of the studies, the values of the standard deviations were less than 3%, showing repeatability and intermediate precision adequate for the analytical method in question. The limit of detection was determined as 3.6 ng/mL. The limit of quantification was determined as 12 ng/mL. The chromatographic method was robust under the proposed Conclusion: The proposed method can be applied to quality control of 6-MP oral suspension to ensure that the required content is delivered to pediatric oncology patients.