Carolina Bonet Bub

Platelet antibody detection by flow cytometry: an effective method to evaluate and give transfusional support in platelet refractoriness

Background Immune platelet refractoriness is mainly caused by human leukocyte antigen antibodies (80-90% of cases) and, to a lesser extent, by human platelet antigen antibodies. Refractoriness can be diagnosed by laboratory tests and patients should receive compatible platelet transfusions. A fast, effective and low cost antibody-screening method which detects platelet human leukocyte/platelet antigen antibodies is essential in the management of immune platelet refractoriness. Objective The aim of this study was to evaluate the efficiency of the flow cytometry platelet immunofluorescence test to screen for immune platelet refractoriness. Methods A group of prospective hematologic patients with clinically suspected platelet refractoriness treated in a referral center in Campinas, SP during July 2006 and July 2011 was enrolled in this study. Platelet antibodies were screened using the flow cytometry platelet immunofluorescence test. Anti-human leukocyte antigen antibodies were detected by commercially available methods. The sensitivity, specificity and predictive values of the immunofluorescence test were determined taking into account that the majority of antiplatelet antibodies presented human leukocyte antigen specificity. Results Seventy-six samples from 32 female and 38 male patients with a median age of 43.5 years (range: 5-84 years) were analyzed. The sensitivity of the test was 86.11% and specificity 75.00% with a positive predictive value of 75.61% and a negative predictive value of 85.71%. The accuracy of the method was 80.26%. Conclusion This study shows that the flow cytometry platelet immunofluorescence test has a high correlation with the anti-human leukocyte antigen antibodies. Despite a few limitations, the method seems to be efficient, fast and feasible as the initial screening for platelet antibody detection and a useful tool to crossmatch platelets for the transfusional support of patients with immune platelet refractoriness.

Induction of platelet refractoriness after myeloablative unrelated allogeneic hematopoietic peripheral blood progenitor cell transplant from HLA-sensitized female donor.

enterocolitis: a meta-analysis of observational data. Pediatrics 2012;129:529-40. 3. American Academy of Pediatrics Subcommittee on Hyperbilirubinemia. Management of hyperbilirubinemia in the newborn infant 35 or more weeks of gestation. Pediatrics 2004;114:297-316. 4. van Imhoff DE, Dijk PH, Hulzebos CV; BARTrial study group, Netherlands Neonatal Research Network. Uniform treatment thresholds for hyperbilirubinemia in preterm infants: background and synopsis of a national guideline. Early Hum Dev 2011;87:521-5.

RHD alleles among pregnant women with serologic discrepant weak D phenotypes from a multiethnic population and risk of alloimmunization

A considerable number of RHD alleles responsible for weak and partial D phenotypes have been identified. Serologic determination of these phenotypes is often doubtful and makes genetic analysis of RHD gene highly desirable in transfusion recipients and pregnant women. We analyzed the RHD gene in a cohort of pregnant women with doubtful D phenotypes.

Determination of an unrelated donor pool size for human leukocyte antigen-matched platelets in Brazil

Background Successful transfusion of platelet refractory patients is a challenge. Many potential donors are needed to sustain human leukocyte antigen matched-platelet transfusion programs because of the different types of antigens and the constant needs of these patients. For a highly mixed population such as the Brazilian population, the pool size required to provide adequate platelet support is unknown. Methods A mathematical model was created to estimate the appropriate size of an unrelated donor pool to provide human leukocyte antigen-compatible platelet support for a Brazilian population. A group of 154 hematologic human leukocyte antigen-typed patients was used as the potential patient population and a database of 65,500 human leukocyte antigen-typed bone marrow registered donors was used as the donor population. Platelet compatibility was based on the grading system of Duquesnoy. Results Using the mathematical model, a pool containing 31,940, 1710 and 321 donors would be necessary to match more than 80% of the patients with at least five completely compatible (no cross-reactive group), partial compatible (one cross-reactive group) or less compatible (two cross-reactive group) donors, respectively. Conclusion The phenotypic diversity of the Brazilian population has probably made it more difficulty to find completely compatible donors. However, this heterogeneity seems to have facilitated finding donors when cross-reactive groups are accepted as proposed by the grading system of Duquesnoy. The results of this study may help to establish unrelated human leukocyte antigen-compatible platelet transfusions, a procedure not routinely performed in most Brazilian transfusion services.

Variant RHD Types in Brazilians With Discrepancies in RhD Typing

The knowledge of D variants in patients and donors is important because anti‐D alloimmunization can occur in some but not all individuals who express a variant RHD allele. Serologic distinction of RhD discrepancies is not always straightforward, which makes molecular analysis highly desirable.

Eosinophil chimerism in the differential diagnosis between DEK-NUP214-positive acute myeloid leukaemia relapse and chronic graft-versus-host disease

Eosinophilia is a rare, recurrent finding in acute myeloid leukaemia (AML). The classic cases include core-binding factor AMLs with chromosome 16 abnormalities and AMLs with rearrangements of the platelet derived growth factor (PDGF) receptor A and B genes ( PDGFRA and PDGFRB ) and the fibroblast growth factor receptor 1 gene ( FGFR1 ). AML with t(6;9)(p23;q24) is a rare entity (0.7%–1.8% of all AMLs), characterised by multilineage dysplasia, basophilia and an unfavourable prognosis.1–3 This cytogenetic alteration leads to the formation of the DEK-NUP214 hybrid protein, and usually presents as a single abnormality, but it can also be associated with a complex karyotype.4 There are currently no descriptions of eosinophilia associated with DEK-NUP214+ AML. We report the case of a 16-year-old male patient who presented with generalised cutaneous pruritus and fever, associated with peripheral blood eosinophilia (absolute count 7830 cells/μL) in August 2010. After ruling out common causes of secondary eosinophilia, the patient was submitted to bone marrow aspiration, which showed erythroid hyperplasia (58.8%) with dyserythropoiesis, eosinophilia (16.4%), dysgranulopoiesis and 9.6% blast cells. These findings were compatible with the diagnosis of AML-M6, according to the French–American–British classification. A cytogenetic study showed the presence of t(6;9) (p23;q34) as the sole anomaly. Fluorescence in-situ hybridisation (FISH) was negative for inv(16), and molecular studies showed wild-type sequences for the fms-related tyrosine kinase 3 ( FLT3 ) and nucleophosmin ( NPM1 ). FISH was also negative for PDGFRA rearrangement. The patient was treated with two cycles of cytarabine-based chemotherapy, achieving haematological remission; nevertheless, peripheral …

The impact of preapheresis white blood cell count on autologous peripheral blood stem cell collection efficiency and HSC infusion side effect rate

Autologous peripheral blood hematopoietic stem cell (PBSC) collection efficiency (CE) is reportedly affected by the patients blood properties; however, studies to identify factors correlated with CE have shown inconsistent results. Additionally, variables such as stem cell graft granulocyte content and patient age, sex, and underlying disease, may be associated with hematopietic stem cell (HSC) infusion‐related adverse reactions. In this study, we evaluated the correlation of preleukapheresis PB granulocyte count and PBSC harvest variables with CD34+collection yield and efficiency, and thawed HSC infusion side effect occurrence.

Transfusion management for patients taking an anti-CD38 monoclonal antibody

Introduction Pre-transfusion tests, essential for the release of blood components, may be affected by drugs. Monoclonal antibodies represent a class of medications increasingly used in the clinical practice, with anti-CD38 monoclonal antibodies (daratumumab) being a promising resource in the treatment of refractory myeloma. This monoclonal antibody recognizes CD38 in myeloma cells and interferes with pre-transfusion tests by causing panreactivity in indirect antiglobulin tests thereby clinically masking alloantibodies. Dithiothreitol is a reagent that breaks disulfide bonds and effectively destroys antigenic sites for CD38 on red blood cells. This study reports the immunohematological findings of pre-transfusion tests of patients with multiple myeloma receiving daratumumab and on solutions to prevent the interference of this monoclonal antibody. Methods Serum samples from five patients on anti-CD38 monoclonal antibody treatment were evaluated. Tests performed included ABO/RhD typing, indirect antiglobulin test, direct antiglobulin test and eluate test. A daily evaluation was performed to determine the shelf life of dithiothreitol-treated red blood cells when stored in Alsevers solution. Results No interference in the ABO/RhD typing results was noted but in all samples, a panreactivity was observed in indirect antiglobulin tests. Regarding the direct antiglobulin test, two samples presented positive results but negative eluates. In all samples, treatment of reagent red blood cells with 0.2 M dithiothreitol offset interference by anti-CD38 monoclonal antibodies. Dithiothreitol-treated red blood cells stored in Alsevers solution were stable for up to 15 days. Conclusion Treatment of reagent red blood cells with dithiothreitol can be efficient and accessible to offset the interference of the anti-CD38 drug in pre-transfusion tests. The number of costly serological workups can be reduced by having stored dithiothreitol red blood cells with this proving to be a useful reagent for investigating anti-CD38.

Hiperplasia angiolinfoide como causa de eosinofilia

Angiolymphoid hyperplasia (Hale) and Kimura disease are two entities that can manifest as subcutaneous nodules, plaques, or papules, and the predominant localization is face, retroauricular and cervical region. They are rare causes of eosinophilia and there is discussion regarding their etiopathogenesis. Some authors propose that these two diseases are truly individual, but others say that they are separate points on a single spectrum. This article is a case report of an asian patient that showed a one year duration of generalized pruritus, with papules on the limbs and a 5 centimeter nodule on the right retroauricular region with slow progression of the size. The hemogram showed leucocitosis with eosinophilia. These findings suggest an overlap between these two diseases, they are clinically suggestive of Kimura disease diagnosis, but the histopathology with HE and immunohistochemistry confirmed the endothelial origin of the lesion that was compatible with Hale. The authors emphasize the rarity of the case as the cause of eosinophilia, also alert for the challenge of the diagnosis and distinction between these two diseases.