RESUMO
RH allele variability is caused by several types of variants, resulting in altered RhD and RhCE phenotypes. Most of the weak D phenotypes in European-derived populations are weak D types 1, 2, or 3, which are not involved in alloimmunization episodes. However, the Brazilian population is racially diverse, and the accuracy of molecular and serologic tests developed in recent years has allowed for the identification of other RH variants, that are common in the Brazilian population, such as weak D type 38 or weak partial 11, the latter involved in alloimmunization cases. Furthermore, patients with these two weak D variants must be transfused with D- red blood cell units, as do patients with weak D type 4 or DAR, which are also common D variants in Brazil. Weak D type 38 and weak partial 11 can be serologically misclassified as weak D types 1, 2, or 3 in patients, based on European experience, or as D- in donors. Additionally, pregnant women may unnecessarily be identified as requiring Rh immune globulin. RhCE phenotypes are reliable indicators of RhD variants. For individuals with the Dce phenotype, the preferred approach is to specifically search for RHD*DAR. However, when encountering DCe or DcE phenotypes, we currently lack a developed method that assists us in rapidly identifying and determining the appropriate course of action for the patient or pregnant woman. Two multiplex assays were proposed: one for the identification of RHD*weak partial 11, RHD*weak D type 38, and RHD*weak D type 3 and another for RHD*weak D type 2 and RHD*weak D type 5. The multiplex assays were considered valid if the obtained results were equivalent to those obtained from sequencing. Expected results were obtained for all tested samples. The proposed multiplex allele-specific polymerase chain reaction assays can be used in the molecular investigation of women of childbearing age, patients, and blood donors presenting a weak D phenotype with DCe or DcE haplotypes in a mixed-race population, such as Brazil.
Assuntos
Antígenos de Grupos Sanguíneos , Sistema do Grupo Sanguíneo Rh-Hr , Humanos , Feminino , Gravidez , Genótipo , Brasil , Sistema do Grupo Sanguíneo Rh-Hr/genética , Fenótipo , Doadores de Sangue , Alelos , Padrões de ReferênciaRESUMO
BACKGROUND AND OBJECTIVES: Transfusion-related acute lung injury (TRALI) is characterized by leukocyte transmigration and alveolar capillary leakage shortly after transfusion. TRALI pathogenesis has not been fully elucidated. In some cases, the infusion of alloantibodies (immune model), whereas in others the combination of neutrophil priming by proinflammatory molecules with the subsequent infusion of biological response modifiers (BRMs) in the hemocomponent (non-immune model) have been implicated. Our aim was to compare the pathological events involved in TRALI induced by antibodies or BRMs using murine models. MATERIALS AND METHODS: In the immune model, human HNA-2(+) neutrophils were incubated in vitro with a monoclonal antibody (anti-CD177, clone 7D8) directed against the HNA-2 antigen and injected i.v. in NOD/SCID mice. In the non-immune model, BALB/c mice were treated with low doses of lipopolysaccharide (LPS) followed by platelet-activating factor (PAF) infusion 2 h later. Forty minutes after PAF administration, or 6 h after neutrophil injection, lungs were isolated and histological analysis, determination of a variety of cytokines and chemokines including keratinocyte-derived chemokine (KC), MIP-2, the interleukins IL-1ß, IL-6, IL-8 as well as TNFα, cell influx and alveolar capillary leakage were performed. RESULTS: In both models, characteristic histological findings of TRALI and an increase in KC and MIP-2 levels were detected. In contrast to the immune model, in the non-immune model, there was a dramatic increase in IL-1ß and TNFα. However, capillary leakage was only detected if PAF was administrated. CONCLUSIONS: Regardless of the triggering event(s), KC, MIP-2 and integrins participate in TRALI pathogenesis, whereas PAF is essential for capillary leakage when two events are involved.
Assuntos
Lesão Pulmonar Aguda/imunologia , Lesão Pulmonar Aguda/patologia , Reação Transfusional , Lesão Pulmonar Aguda/etiologia , Animais , Quimiocinas/imunologia , Modelos Animais de Doenças , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos NOD , Camundongos SCID , Neutrófilos/imunologia , Neutrófilos/patologiaRESUMO
INTRODUCTION: Autoimmune haemolytic anaemia (AIHA) is defined as the increased destruction of red blood cells (RBCs) in the presence of anti-RBC autoantibodies and/or complement. Its pathogenesis is multifactorial and includes changes in mechanisms of cytokine production and functionality. A number of recent studies have implicated cytokines polymorphisms in the pathogenesis of autoimmune diseases. The aim of this study was to determine the frequency of polymorphisms of tumour necrosis factor alpha (TNF-α), lymphotoxin-α (LT-α), interleukin 10 (IL-10), interleukin 12 (IL-12) and cytotoxic T-lymphocyte antigen-4 (CTLA-4) in patients with AIHA in comparison with healthy individuals. METHODS: The study population consisted of 17 patients with AIHA and 40 healthy controls. The polymorphisms for TNF-α-308, LT-α +252, IL-10 -592, IL-12 +1188 and CTLA-4 +49 were examined by polymerase chain reaction followed by specific restriction enzyme digestion. RESULTS: There was no significant difference in the phenotypic distributions of polymorphisms of the TNF-α, IL-10, IL-12 and CTLA-4 between the patients and controls. Compared with healthy controls, patients with AIHA had a significant higher frequency of LT-α (+252) AG phenotype (41%vs. 13%; P = 0.032). CONCLUSION: In this study, no significant differences on the frequency of TNF-α, IL-10, IL-12 and CTLA-4 polymorphisms between patients with AIHA and controls was found, suggesting that the targeted polymorphisms do not influence on the emergence and evolution of the disease. However, the LT-α +252 polymorphism might have an effect for AIHAI development, suggesting that further studies are necessary to clear up this question.
Assuntos
Anemia Hemolítica Autoimune/genética , Antígeno CTLA-4/genética , Citocinas/genética , Polimorfismo Genético , Adolescente , Adulto , Idoso , Feminino , Humanos , Interleucina-10/genética , Interleucina-12/genética , Linfotoxina-alfa/genética , Masculino , Pessoa de Meia-Idade , Fator de Necrose Tumoral alfa/genéticaRESUMO
The RHD gene is highly polymorphic and the existence of a large number of alleles results in RhD variant phenotypes. RHD genotyping has been used to distinguish normal D antigen from D variants due to limitations of serologic methods. The purpose of this study was to determine the phenotypic frequency of RhD and RhCE antigens and to investigate the RHD alleles present in samples with the weak D or D- phenotypes from Brazilian blood donors. A total of 2007 donors were phenotyped for D, C, c, E and e antigens. Samples phenotyped as D- were genotyped by polymerase chain reaction-sequence specific primers, and exon 10 and intron 4 of the RHD gene were analysed. D- samples containing the RHD gene or samples considered weak D were further characterised using genotyping platform or nucleotide sequencing. Using serologic methods we found that 87.3% of the donors were D+, 11.9% D- and 0.8% weak D. The frequency of RHD gene in D- individuals was 9.2%. Five RHD alleles from phenotypically D- donors were characterised in six molecular backgrounds: RHDΨ, RHD-CE-D(s), RHD-CE-(2-9)-D, RHD/RHDΨ, RHDΨ/RHD-CE-D(s) and RHD-CE(2)-D. The most common weak D antigens types found were 1, 3, 4.0/4.1 and 4.2, whereas the most prevalent weak D type was 4.2 (or DAR). The RHD genotyping proved to be a necessary tool to characterise RHD alleles in donors phenotyped as D- or weak D to increase the transfusion safety in highly racial mixed population.
Assuntos
Alelos , Doadores de Sangue , Frequência do Gene/genética , Fenótipo , Sistema do Grupo Sanguíneo Rh-Hr/genética , Brasil , Éxons/genética , Feminino , Humanos , Íntrons/genética , Masculino , Reação em Cadeia da Polimerase/métodosRESUMO
BACKGROUND AND OBJECTIVES: The human neutrophil antigen-2 (HNA-2) is expressed on a subpopulation of neutrophils as most subjects present a negative plus a positive HNA-2 population of neutrophils. The number of neutrophils expressing HNA-2 is variable and may increase in pregnancy, infections, myeloproliferative disorders and after G-CSF. This study investigated the presence of polymorphisms in the gene encoding HNA-2 (CD177) in individuals presenting different patterns of antigen expression and determined the association of single nucleotide polymorphisms (SNPs) with the heterogeneous HNA-2 expression. MATERIALS AND METHODS: Flow cytometry was employed to analyse the HNA-2 expression on neutrophils from 135 healthy subjects using two monoclonal antibodies (TAG4, 7D8). Sequencing reactions were performed on subjects whose antigen expression was low (< or = 50%), high (> or = 80%) or atypical (a nonreactive population plus two distinct positive cell populations). RESULTS: Five SNPs were detected, two of them (A793C, G1084A) were related to a low expression of HNA-2 (P = 0.031 and P = 0.004). Atypical antigen expression was observed in 5.9% (8/135) of the individuals, three nonpregnant women and five men. In these cases, the cDNA sequences revealed three SNPs (A134T, G156A and G1333A) strongly related to this atypical HNA-2 expression (P = 0.004, P = 0.006 and P < 0.0001, respectively). CONCLUSIONS: Our data show that polymorphisms in the CD177 are associated with variations in the HNA-2 expression and may be the cause of atypical expressions.
Assuntos
Isoantígenos/genética , Glicoproteínas de Membrana/genética , Neutrófilos/imunologia , Receptores de Superfície Celular/genética , Adulto , Feminino , Citometria de Fluxo , Proteínas Ligadas por GPI , Humanos , Isoantígenos/biossíntese , Isoantígenos/sangue , Isoantígenos/imunologia , Masculino , Glicoproteínas de Membrana/biossíntese , Glicoproteínas de Membrana/sangue , Glicoproteínas de Membrana/imunologia , Pessoa de Meia-Idade , Neutrófilos/metabolismo , Polimorfismo de Nucleotídeo Único , Receptores de Superfície Celular/biossíntese , Receptores de Superfície Celular/sangue , Receptores de Superfície Celular/imunologia , Adulto JovemRESUMO
Human neutrophil reactive antibodies may cause clinical disorders such as transfusion-related acute lung injury, febrile transfusion reactions, alloimmune neonatal neutropenia, immune neutropenia after stem cell transplantation, refractoriness to granulocyte transfusion, drug-induced neutropenia and autoimmune neutropenia. Using the granulocyte immunofluorescence test by flow cytometry, the phenotypic frequencies of the human neutrophil alloantigens (HNA)-1a, -1b, -2, -3a and -4a were determined in 100 healthy Brazilian persons. Neutrophils were separated from blood samples by sedimentation, centrifugated and incubated with HNA-specific alloantibody plus fluorescein isothiocyanate-labeled F(ab')(2) fragments of anti-human IgG. The results showed that the phenotype frequencies of HNA-1a, -1b, -2a, -3a and -4a were 65%, 83%, 97%, 95% and 94%, respectively. We detected that neutrophils from 17% of Brazilians typed positive only with anti-HNA-1a (HNA-1a/a), 35% only with anti-HNA-1b (HNA-1b/b) and 48% reacted with both antibodies (HNA-1a/b). The frequencies found for HNA-1a and -1b were quite similar to that reported among Africans and American-Africans, but different from those found in Japanese and Chinese. In addition, our data showed that the frequencies of HNA-2, -3a and -4a in Brazilians were comparable with those observed in Caucasians. The determination of HNAs frequencies among populations with distinct racial backgrounds is important not only for anthropological reasons, but also for neonatal typing in suspected cases of alloimmune neutropenia or when patients are severely neutropenic.
Assuntos
Isoantígenos/sangue , Glicoproteínas de Membrana/sangue , Receptores de Superfície Celular/sangue , Brasil/epidemiologia , Proteínas Ligadas por GPI , Humanos , Isoanticorpos/sangue , Isoantígenos/análise , Isoantígenos/metabolismo , Masculino , Glicoproteínas de Membrana/análise , Glicoproteínas de Membrana/metabolismo , Receptores de Superfície Celular/análise , Receptores de Superfície Celular/metabolismo , Estudos SoroepidemiológicosRESUMO
We sought to assess clinical, epidemiological, biochemical, serological and histological characteristics of anti-hepatitis C virus (HCV)-positive female blood donors and compare them with men. As women are frequently the minority among blood donors, studies evaluating this population usually reflect characteristics of male gender. This retrospective study included 380 blood donors with confirmed positive anti-HCV. The mean age was 36.9 +/- 11.3 years and 33.2% were women. Compared with men, female donors showed higher prevalence of prior transfusion of blood products (P = 0.031) and lower prevalence of intravenous drug use (P = 0.001) and alcohol abuse (P < 0.001). Women exhibited lower medians of alanine aminotransferase (P < 0.001) and gamma-glutamyltransferase (P < 0.001). They also showed higher platelet count (P < 0.001) and prothrombin activity (P = 0.049), and a lower frequency of antibody against core antigen of hepatitis B virus (anti-HBc) positivity (P = 0.032). A higher proportion of spontaneous viral clearance (P = 0.001) and a lower frequency of viraemia (P < 0.001) were observed among women. On liver biopsy, women had lower prevalence of fibrosis stage > or = 2. Multivariate analysis identified age (OR = 1.050, 95% CI: 1.019-1.081, P = 0.001) and anti-HBc positivity (OR = 2.184, 95% CI: 1.010-4.722, P = 0.047) as independent predictors of significant fibrosis. Female blood donors presented higher prevalence of spontaneous viral clearance as well as biochemical and histological evidence of less advanced liver disease. These findings could be because of intrinsic characteristics of female gender or secondary to associated factors such as younger age or anti-HBc positivity.
Assuntos
Doadores de Sangue , Anticorpos Anti-Hepatite C/sangue , Hepatite C/epidemiologia , Adulto , Feminino , Fibrose , Hepatite C/diagnóstico , Humanos , Fígado/patologia , Masculino , Pessoa de Meia-Idade , Prevalência , Estudos Retrospectivos , Fatores Sexuais , ViremiaRESUMO
BACKGROUND AND OBJECTIVES: Benefits of adopting restrictive guidelines for erythrocyte transfusions are still controversial. The objective of this study was to verify if a very strict guideline could reduce erythrocyte transfusions in preterm infants without adverse outcomes. MATERIALS AND METHODS: Two prospective cohorts of neonates with gestational age < 37 weeks and birth weight < 1500 g were studied. Neonates born in Period 1 were submitted to a strict guideline for erythrocyte transfusions. In Period 2, a new stricter protocol was introduced. Infants of both periods were compared regarding number of transfusions and clinical outcome. RESULTS: The median number of transfusions decreased from 2 (1 to 14) in Period 1 to 1 (1-9), P = 0.001, in Period 2. The linear regression multivariate analysis showed that the implementation of the stricter guideline was associated with a reduction in the number of transfusions received by patients by 0.55 (95% confidence interval: -0.08; -1.02) units/patients. Number of apnea episodes, weight at 28 days of life and days of hospital stay were similar in both periods. Intra-hospital death was lower in Period 2. CONCLUSION: A very strict guideline reduced the number of erythrocyte transfusions in preterm infants, without threatening their clinical course.
Assuntos
Transfusão de Eritrócitos/estatística & dados numéricos , Fidelidade a Diretrizes , Doenças do Prematuro/terapia , Guias de Prática Clínica como Assunto , Apneia/epidemiologia , Hemorragia Cerebral/epidemiologia , Estudos de Coortes , Transfusão de Eritrócitos/normas , Feminino , Idade Gestacional , Hematócrito , Mortalidade Hospitalar , Humanos , Hipóxia/epidemiologia , Hipóxia/prevenção & controle , Recém-Nascido , Recém-Nascido Prematuro , Doenças do Prematuro/epidemiologia , Doenças do Prematuro/prevenção & controle , Recém-Nascido Pequeno para a Idade Gestacional , Recém-Nascido de muito Baixo Peso , Tempo de Internação/estatística & dados numéricos , Masculino , Flebotomia/efeitos adversos , Respiração com Pressão Positiva/estatística & dados numéricos , Estudos ProspectivosRESUMO
It is well established that interleukin-6 (IL-6) is an essential growth factor for multiple myeloma (MM) and patients with increased IL-6 levels have a poor prognosis. In healthy subjects, the presence of the C allele at a polymorphic site (-174 G/C) of the IL-6 gene is related to low IL-6 levels. In view of the potential association of this particular polymorphism with IL-6 concentration, and the relevance of IL-6 in MM pathogenesis, the objective of the present study was to investigate the prevalence of IL-6 (-174 G/C) promoter polymorphism and its association with development of MM in Brazilian individuals. We investigated the prevalence of these alleles in 52 patients and 60 healthy subjects (matched by age, sex, and race) of a Brazilian population. Thirty patients were male (42.4%), 24 (46.2%) were white and the median age at diagnosis was 58.5 years (range: 28 to 84 years). To determine the IL-6 (-174 G/C) polymorphism, molecular analysis was performed by polymerase chain reaction followed by endonuclease restriction digestion. The genotype distributions observed in the group of patients were 4% CC, 42% GC and 54% GG. The C allele frequency was 0.25. These results were similar to the control group, suggesting no impact of this polymorphism on the susceptibility to MM.