FRANCISCO CARLOS ALMEIDA GOMES
Índice h a partir de 2011
4
Projetos de Pesquisa
Unidades Organizacionais
Instituto Central, Hospital das Clínicas, Faculdade de Medicina
4 resultados
Resultados de Busca
Agora exibindo 1 - 4 de 4
- Defining the clinical relevance of red blood cell autoantibodies by Monocyte Monolayer Assay(2018) CONRADO, Marina C. A. V.; D'AVILA, Amanda N.; VIEIRA, Juliana B.; BONIFACIO, Silvia L.; GOMES, Francisco C. A.; DEZAN, Marcia R.; OLIVEIRA, Valeria B.; RIBEIRO, Ingrid H.; TUCUNDUVA, Luciana T. C. M.; MENDRONE-JUNIOR, Alfredo; ROCHA, Vanderson; DINARDO, Carla L.BackgroundThe Monocyte Monolayer Assay (MMA) is an in vitro simulation of red blood cell (RBC) alloantibody behavior. It has been classically applied to predict the risks of post-transfusion hemolytic reactions when transfusing incompatible RBC units. Quantifying erythrophagocytosis by MMA may be an interesting option for situations where there is doubt whether a RBC autoantibody is mediating significant hemolysis. Here, we present three situations involving RBC autoantibodies in which the MMA was decisive for clarifying the diagnosis and choosing the best clinical treatment. Case ReportCase 1. Pregnant patient with severely anemic fetus exhibited warm autoantibody without signs of hemolysis. MMA revealed 30% of monocyte index (MI) highlighting that fetal hemolysis was caused by maternal autoantibody. Prednisone was prescribed with fetal clinical improvement. Cases 2 and 3. Two patients with the diagnosis of mixed auto-immune hemolytic anemia and poor response to corticosteroids were evaluated using MMA. The resulting MI was less than 10% in both cases, suggesting that the cold-agglutinin rather than the warm auto-IgG was responsible for overt hemolysis. Treatment with rituximab was begun, with good clinical response. ConclusionMMA can be used to evaluate the ability of RBC autoantibodies to mediate overt hemolysis. It can be especially useful to determine the role played by cold and warm auto-antibodies in mixed auto-immune hemolytic disease, helping to define the best treatment option.
- Prophylactic strategies for acute hemolysis secondary to plasma-incompatible platelet transfusions: correlation between qualitative hemolysin test and isohemagglutinin titration(2015) LANDIM, Cinthia Silvestre; GOMES, Francisco Carlos Almeida; ZEZA, Bernardete Martin; MENDRONE-JÚNIOR, Alfredo; DINARDO, Carla LuanaOBJECTIVE: Brazilian legislation has recently suggested the use of the qualitative hemolysin test instead of isohemagglutinin titers as prophylaxis for acute hemolysis related to plasma-incompatible platelet transfusions. The efficacy of this test in preventing hemolytic reactions has never been evaluated while isohemagglutinin titers have been extensively studied. The main objective of this study was to evaluate the correlation between the results of these two tests. The impact of each type of prophylaxis on the platelet inventory management and the ability of the qualitative hemolysin test to prevent red cell sensitization after the transfusion of incompatible units were also studied.METHODS: A total of 246 donor blood samples were evaluated using both isohemagglutinin titers and the qualitative hemolysin test, and the results were statistically compared. Subsequently, 600 platelet units were tested using the hemolysin assay and the percentage of units unsuitable for transfusion was compared to historical data using isohemagglutinin titers (cut-off: 100). Moreover, ten patients who received units with minor ABO incompatibilities that were negative for hemolysis according to the qualitative hemolysin test were evaluated regarding the development of hemolysis and red cell sensitization (anti-A or anti-B).RESULTS: Isohemagglutinin titration and the results of qualitative hemolysin test did not correlate. The routine implementation of the qualitative hemolysin test significantly increased the percentage of platelet units found unsuitable for transfusions (15-65%; p-value <0.001). Furthermore the qualitative hemolysin test did not prevent red blood cell sensitization in a small exploratory analysis.CONCLUSION: Qualitative hemolysin test results do not correlate to those of isohemagglutinin titers and its implementation as the prophylaxis of choice for hemolysis associated with plasma-incompatible platelet transfusions lacks clinical support of safety and significantly affects platelet inventory management.
- Evaluation of the applicability and effectiveness of a molecular strategy for identifying weakD and DEL phenotype among D- blood donors of mixed origin exhibiting high frequency of RHD*(2018) DEZAN, Marcia Regina; GUARDALINI, Luis Giovani O.; PESSOA, Elaine; RIBEIRO, Ingrid Helena; OLIVEIRA, Valeria Brito; LUZ, Fabio; NOVAC, Denise Rossite; GALLUCCI, Antonio; BONIFACIO, Silvia; GOMES, Francisco; LEVI, Jose E.; PEREIRA, Alexandre C.; KRIEGER, Jose E.; MENDRONE-JUNIOR, Alfredo; ROCHA, Vanderson; DINARDO, Carla LuanaBACKGROUNDMolecular tests designed to detect the presence of active RHD gene among D- donors have been successfully applied in people of European ancestry, but not in admixed populations with a considerable frequency of RHD*. Our goal was to evaluate the performance of a molecular screening tool for identifying active RHD alleles among Brazilian blood donors classified as D- C+ and/or E+. STUDY DESIGN AND METHODSPools of five DNA samples of serologically D- C+ and/or E+ donors were checked by a RHD polymerase chain reaction (PCR) assay specific for RHD Intron 4 and Exon 7. When a pool result was positive, samples were genotyped individually for RHD Intron 4 and Exon 7, RHD*, RHCE*Cc, and RHD zygosity. Donors suspected of active RHD gene were further evaluated by whole-coding region and flanking intron direct sequencing. RESULTSA total of 405 donors were included. Two percent exhibited active RHD gene, codifying D-weak (38 and 45) or DEL phenotype. The most prevalent DEL allele was RHD*DEL1 (c.1227G>A), which is proven to be immunogenic. A high frequency of RHD* was detected in the donors with nondeleted RHD alleles (31%), far superior to the frequency of RHD variant alleles (15.5%). The proposed approach presented sensitivity of 100% and specificity of 85.7% for identifying active RHD gene. CONCLUSIONThe strategy of checking D- donors with RHD PCR followed by exclusion of RHD* allele has proved efficient in identifying weak-D and DEL phenotype in the Brazilian population.
- RHD and RHCE genotyping by next-generation sequencing is an effective strategy to identify molecular variants within sickle cell disease patients(2017) DEZAN, Marcia R.; RIBEIRO, Ingrid Helena; OLIVEIRA, Valeria B.; VIEIRA, Juliana B.; GOMES, Francisco C.; FRANCO, Lucas A. M.; VARUZZA, Leonardo; RIBEIRO, Roberto; CHINOCA, Karen Ziza; LEVI, Jose Eduardo; KRIEGER, Jose Eduardo; PEREIRA, Alexandre Costa; GUALANDRO, Sandra F. M.; ROCHA, Vanderson G.; MENDRONE-JUNIOR, Alfredo; SABINO, Ester Cerdeira; DINARDO, Carla LuanaBackground: The complexity of Rh genetic variation among sickle cell disease (SCD) patients is high. Conventional molecular assays cannot identify all genetic variants already described for the RH locus as well as foresee novel alleles. Sequencing RHD and RHCE is indicated to broaden the search for Rh genetic variants. Aims: To standardize the Next Generation Sequencing (NGS) strategy to assertively identify Rh genetic variants among SCD patients with serologic suspicion of Rh variants and evaluate if it can improve the transfusion support. Methods: Thirty-five SCD patients with unexplained Rh antibodies were enrolled. A NGS-based strategy was developed to genotype RHD and RHCE using gene-specific primers. Genotype and serological data were compared. Results: Data obtained from the NGS-based assay were gene-specific. Ten and 25 variant RHD and RHCE alleles were identified, respectively. Among all cases of unexplained Rh antibodies, 62% had been inaccurately classified by serological analysis and, of these, 73.1% were considered as relevant, as were associated with increased risk of hemolytic reactions and shortage of units suitable for transfusion. Conclusion: The NGS assay designed to genotype RH coding regions was effective and accurate in identifying variants. The proposed strategy clarified the Rh phenotype of most patients, improving transfusion support.