Publications by authors named "Afonso Cortez"

Background And Objectives: Sickle cell trait (SCT) persons are significant donors, and discarding these blood units reduces their supplies, mainly in the third-world countries. This work focused on 12 metabolites associated with the red blood cell (RBC) storage lesion and 23 amino acids in the supernatants of packed RBC units from SCT and reference (non-SCT) donors stored in the same conditions.

Materials And Methods: All samples of RBC concentrates were collected and separated from the storage of Colsan (Beneficient Association of Blood Collection), where they were routinely processed and separated as packed RBC units and stored in the refrigerator (2°-6°C).

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The high number of D variants can lead to the unnecessary use of Rh immune globulin, overuse of D- RBC units, and anti-D allommunization. D variant prevalence varies among ethnic groups, and knowledge of the main variants present in a specific population, their behavior in serologic tests, and their impact on clinical practice is crucial to define the best serologic tests for routine use. The present study aimed to explore the serologic profile of D variants and to determine which variants are most associated with false-negative D typing results and alloimmunization.

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Background And Objectives: Gerbich (GE) blood group system carries high-frequency antigens and the absence of them leads to rare phenotypes: GE:-2,3,4, GE:-2,-3,4 and GE:-2,-3,-4. Their serological differentiation is limited and misclassification of Gerbich phenotypes may occur, but this can be avoided by molecular characterization. This study aimed to characterize the molecular background responsible for rare Gerbich phenotypes in Brazilian population.

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Background: Several centers have selected Black donors to prevent Rh alloimmunization of patients with sickle cell disease (SCD). As the Brazilian population is considered very admixed and race definition by self-declaration is questionable, this study aimed to compare RHCE diversity among patients with SCD and selected groups of Brazilian blood donors to define which group of donors would be the adequate red cell supply for patients with SCD.

Method: We compared RHCE allele frequencies between patients with SCD and four groups of Brazilian blood donors: self-declared Black donors (SDB), donors with predominant African genetic markers (AAM), donors with weak D expression (WDD), and random donors (RDs).

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Background: Red blood cell (RBC) alloimmunization is a complication of patients with sickle cell disease (SCD) and it has a greater impact on pregnancy, leading to a risk of hemolytic disease of the newborn and reducing blood availability for pregnant women. This study proposed to evaluate antigen matching transfusion protocols, aiming to reduce RBC alloimmunization in Brazilian female patients with SCD.

Methods: Samples from female patients with SCD (153) and self-declared Afro-Brazilian donors (307) were genotyped for RBC antigens and RH variants were investigated.

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Introduction: As coronavirus disease-2019 (COVID-19) spread worldwide and social restrictions were intensified, difficulties in blood supply were expected to result in a shortage of blood donors, logistic issues and a change in blood consumption. Consequences could be detrimental to the meeting of the blood supply demand, especially in a decentralized blood bank in the State of São Paulo responsible for providing blood to more than 100 hospitals, mostly of the public health system. Aiming to minimize negative effects and focusing on maintenance of the blood supply, a different approach was discussed and adopted.

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Background: We evaluated different technological approaches and anti-D clones to propose the most appropriate serologic strategy in detecting the largest numbers of D variants in blood donors.

Methods: We selected 101 samples from Brazilian blood donors with different expressions of D in our donor routine. The tests were performed in immediate spin (IS) with eleven commercially available anti-D reagents in a tube and microplate.

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Background: Laboratory testing to identify the molecular basis of serologic weak D phenotypes is recommended to determine whether a pregnant woman or potential transfusion recipient should be managed as RhD-positive or RhD-negative. The variation in D antigen expression on RBCs, different potencies of anti-D typing reagents, lack of standardized test methods, and the subjectivity of interpreting agglutination reactions complicate the detection of D variants. We evaluated the correlation of agglutination scores by an automated immunoassay analyzer with D antigen densities determined by flow cytometry, and D variant types identified by molecular analysis.

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Background: Hodgkin's lymphoma has high rates of cure, but in 15% to 20% of general patients and between 35% and 40% of those in advanced stages, the disease will progress or will relapse after initial treatment. For this group, hematopoietic stem cell transplantation is considered one option of salvage therapy.

Objectives: To evaluate a group of 106 patients with Hodgkin's lymphoma, who suffered relapse or who were refractory to treatment, submitted to autologous hematopoietic stem cell transplantation in a single transplant center.

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Objective: To study the prevalence of celiac disease among blood donor volunteers based on screening by IgA antitissue transglutaminase antibody, followed by a confirmatory small intestine biopsy.

Methods: The transversal study involved 3000 potential blood donors, residing in the city of Sao Paulo, Brazil. The participants were gender divided into 1500 men and 1500 women, with an average age 34.

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