MARCIA REGINA DEZAN
Projetos de Pesquisa
Unidades Organizacionais
LIM/31 - Laboratório de Genética e Hematologia Molecular, Hospital das Clínicas, Faculdade de Medicina
3 resultados
Resultados de Busca
Agora exibindo 1 - 3 de 3
- 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.
- High frequency of variant RHD genotypes among donors and patients of mixed origin with serologic weak-D phenotype(2018) DEZAN, Marcia Regina; OLIVEIRA, Valeria B.; GOMES, Carolina Nunes; LUZ, Fabio; GALLUCCI, Antonio J.; BONIFACIO, Silvia L.; ALENCAR, Cecilia Salete; SABINO, Ester C.; PEREIRA, Alexandre C.; KRIEGER, Jose E.; ROCHA, Vanderson; MENDRONE-JUNIOR, Alfredo; DINARDO, Carla L.Background Goal The current transfusion policy recommended for individuals with serologic weak-D phenotype is based on data derived from European-descent populations. Data referring to the distribution of RH alleles underlying weak-D phenotype among people of mixed origin are yet incomplete, and the applicability of European-based transfusion guidelines to this specific population is questionable. To evaluate the distribution of RHD variant genotype among individuals with serologic weak-D phenotype of both African and European descent. Methods Results Donors and patients of mixed origin and with serologic weak-D phenotype were selected for the study. They were investigated using conventional RHD-PCR assays and RHD whole-coding region direct sequencing. One hundred and six donors and 58 patients were included. There were 47 donors and 29 patients with partial-D genotype (47/106, 44.3%, and 29/58, 50%, respectively). RHD*DAR and RHD*weak D type 38 represented the most common altered RHD alleles among donors (joint frequency of 39.6%), while weak D types 1-3 accounted for 10.4% of the total D variant samples. RHD*DAR was the most common allele identified in the patient group (frequency of 31%), and weak D types 1-3 represented 29.3% of the total. Conclusion The frequency of partial D among mixed individuals with serologic weak-D phenotype is high. They should be managed as D-negative patients until molecular tests are complete.
- Determination of Fetal RHD Genotype Including the RHD Pseudogene in Maternal Plasma(2017) ZIZA, Karen Chinoca; LIAO, Adolfo Wenjaw; DEZAN, Marcia; DINARDO, Carla Luana; JENS, Eduardo; FRANCISCO, Rossana Pulcineli Vieira; MENDRONE JUNIOR, Alfredo; ZUGAIB, Marcelo; LEVI, Jose EduardoObjective: To examine the accuracy of fetal RHD genotype and RHD pseudogene determination in a multiethnical population. Methods: Prospective study involving D-negative pregnant women. Cell-free DNA was extracted from 1 ml of maternal plasma by an automated system (MagNA Pure Compact, Roche) and real-time PCR was performed in triplicate targeting the RHD gene exons 5 and 7. Inconclusive samples underwent RHD pseudogene testing by real-time PCR analysis employing novel primers and probe. Results: A positive result was observed in 128/185 (69.2%) samples and negative in 50 (27.0%). Umbilical cord blood phenotype confirmed all cases with a positive or negative PCR result. Seven (3.8%) cases were found inconclusive (exon 7 amplification only) and RHD pseudogene testing with both conventional and real-time PCR demonstrated a positive result in five of them, while two samples were also RHD pseudogene negative. Conclusion: Real-time PCR targeting RHD exons 5 and 7 simultaneously in maternal plasma is an accurate method for the diagnosis of fetal D genotype in our population. The RHD pseudogene real-time PCR assay is feasible and is particularly useful in populations with a high prevalence of this allele. (C) 2016 Wiley Periodicals, Inc.