Genotyping approach for non-invasive foetal RHD detection in an admixed population.

BACKGROUND: Non-invasive foetal RHD genotyping can predict haemolytic disease of the foetus and the newborn in pregnancies with anti-D alloantibodies and also avoid antenatal anti-D prophylaxis in pregnant women carrying an RHD negative foetus. Considering that the Argentine genetic background is the result of generations of intermixing between several ethnic groups, we evaluated the diagnostic performance of a non-invasive foetal RHD determination strategy to guide targeted antenatal RhD immunoprophylaxis. This algorithm is based on the analysis of four regions of the RHD gene in cell-free foetal DNA in maternal plasma and maternal and paternal RHD genotyping. MATERIALS AND METHODS: DNA from 298 serologically D negative pregnant women between 19-28 weeks gestation were RHD genotyped. Foetal RHD status was determined by real-time PCR in 296 maternal plasma samples. In particular cases, RHDΨ and RHD-CE-Ds alleles were investigated in paternal DNA. Umbilical cord blood was collected at birth, and serological and molecular studies were performed. RESULTS: Of the 298 maternal samples, 288 were D-/RHD- and 10 D-/RHD+ (2 RHD*DAR; 5 RHD-CE-Ds; 3 RHDΨ). Plasma from RHD*DAR carriers was not analysed. Real-time PCR showed 210 RHD+ and 78 RHD- foetuses and 8 inconclusive results. In this latter group, paternal molecular studies were useful to report a RHD negative status in 5 foetuses while only 3 remained inconclusive. All the results, except one false positive due to a silent allele (RHD[581insG]), agreed with the neonatal typing performed in cord blood. DISCUSSION: The protocol used for non-invasive prenatal RHD genotyping proved to be suitable to determine foetal RHD status in our admixed population. The knowledge of the genetic background of the population under study and maternal and paternal molecular analysis can reduce the number of inconclusive results when investigating foetal RHD status.

Natural history of hepatitis C virus infection in a cohort of asymptomatic post-transfused subjects.

UNLABELLED: BACKGROUND & AIMS. Studies about the natural history of hepatitis C virus (HCV) infection report variable progression to cirrhosis depending on study design. Retrospective cross-sectional liver clinic studies overestimate the rate of fibrosis progression due to inclusion of patients with more severe disease leaving mild and asymptomatic patients underrepresented. We evaluated fibrosis progression in a group of "healthy" asymptomatic subjects, attending to a voluntary campaign for the detection of HCV infection. MATERIAL AND METHODS: A detection campaign was launched on subjects transfused before 1993. Of 1699 volunteers, 61(3.6%) had HCV infection. A liver biopsy was performed in 40 (65%). Assessed risk factors for liver fibrosis were: sex, body mass index, alcohol consumption (> 20 g/d - > 40g/d ), genotype, HLA-DRB1 alleles, present age, age at infection and duration of infection. RESULTS: 25 (62.5%) were women with a median age of 52.5 years. The median duration of infection was 21.5 years with a median age at infection of 27 years. As regards fibrosis, 25 (62.5%) had a Low Stage (F0-F1), 8 patients, 20%, had severe fibrosis, one patient (2.5%) had cirrhosis. Alcohol consumption was the only risk factor associated with fibrosis progression. CONCLUSIONS: The low progression to cirrhosis may be explained by the clinical characteristics of our population: asymptomatic middle-aged "healthy" subjects infected at young age. The progression to severe fibrosis was noticeable; hence a longer follow-up might demonstrate changes in this outcome. Significant alcohol consumption clearly worsens the natural history of HCV infection; this is no so evident for occasional or mild alcohol consumers.

Modifications of band 3 and oxidation level of membrane proteins in senescent erythrocytes.

OBJECTIVES: To study membrane proteins modifications in Senescent Red Blood Cells (SeRBC). DESIGN ANDMETHODS: SeRBC were obtained on Percoll gradients. Membrane proteins were analyzed by SDS-PAGE, band 3 by immunoblotting, and protein oxidation by measuring the carbonyl groups. RESULTS: Densitometric analysis showed no change in SeRBC while an increase in band 3 and its degradation products was found. An increase of protein oxidation level was found in SeRBC. CONCLUSIONS: These findings provide further experimental evidence about protein modifications occurring during the RBC lifespan.

Alelos HLA-DRB1 en pacientes infectados con patógenos intracelulares en Rosario, Santa Fe / HLA-DRB1 alleles in patients infected with intracellular pathogens in Rosario, Santa Fe

En el desarrollo de la respuesta inmune a patógenos intracelulares participa el elevado polimorfismo de las moléculas HLA de clase II. El objetivo de este trabajo fue establecer la participación de los alelos HLA-DRB1 en personas con infección con Trypanosoma cruzi (T. cruzi) o con Mycobacterium leprae (M. leprae). Se estudiaron 252 individuos de la ciudad de Rosario, divididos en: 86 personas seropositivas para T cruzi (sin compromiso cardiológico de relevancia), 85 pacientes con diagnóstico de Lepra y 81 individuos controles, sin evidencia de patologías. El ADN genómico fue extraído de sangre periférica utilizando el método de salting out y empleado como templado para amplificar por PCR el segundo exón polimórfico de HLA-DRB1. Los alelos fueron tipificados mediante la técnica de PCR­-SSOP. La comparación de frecuencias mostró prevalencia de los alelos DRB1 *0409 y DRB1 *1503 en los individuos seropositivos para T. cruzi con respecto al grupo control. Por otra parte, el análisis estadístico indicó una disminución significativa del alelo DRB1 *1103 en pacientes con esta tripanosomiasis. Al examinar las frecuencias observamos en el grupo de pacientes con Lepra un aumento significativo de los alelos DRB1 *1401 y DRB1 *1406. Además observamos que las proporciones de los alelos DRB1 *0808 y DRB1 *1103 en los enfermos son significativamente inferiores con respecto al grupo control. Los alelos HLA DRB1 podrían actuar solos o en combinación con otros genes para conferir susceptibilidad o resistencia a estas infecciones en la población de Rosario, Argentina.

In the development of the immune response to intracellular pathogens implicated the high polymorphism of HLA class II molecules. The aim of this study was to establish the involvement of the HLA-DRB1 alleles in infected subjects with T. cruzi or leprosy patients in Rosario, Argentina. We studied 252 individuals who divided into: 86 positive people for T. cruzi without cardiac damage, 85 patients diagnosed with leprosy and controls 81 individuals without evidence of disease. Genomic DNA was extracted from peripheral blood using the standard salting out method and used as a template to amplify by the PCR the polymorphic second exon of the HLA­-DRB1. PCR products were hybridized separately with sequence-specifics oligonucleotides (SSOP). Statistical analysis indicated that of increased frequencies of DRB1 *0409, and DRB1 *1503 in individuals with Chagas' disease. DRB1 *1103 allele was prevalence in the group control and could be associated with resistance to the presence of trypanosomiasis. DRB1 *1401 and DRB1 *1406 alleles were significantly more prevalent in leprosy patients, whereas a decreased frequency of DRB1 *0808 and DRB1 *1103 alleles was found, by comparison with the group control. The HLA-DRB1 alleles could act alone or in combination with other genes to confer differential susceptibility and also protection to these diseases in Rosario, Argentina.

Estudio de las variantes alélicas del gen FUT2 en una población de Rosario, Santa Fe / Allele of FUT2 gen variables in a population of Rosario, Argentina

El estado secretor de un individuo está determinado por el gen Secretor (FUT2), responsable de la presencia de antígenos ABH en las secreciones del organismo. El polimorfismo del gen FUT2 muestra una gran variabilidad dependiente del tipo de población. Alrededor del 20% de los individuos caucásicos son no­secretores y presentan la mutación G428A. El objetivo de este trabajo fue estudiar las variables alélicas del gen FUT2 en una población de Rosario. Se trabajó con muestras de sangre periférica de dadores voluntarios (n=1728). Se determinó el estado secretor en plasma y saliva y el fenotipo Lewis. El ADN genómico fue extraído por la técnica de salting-out modificada y fue analizado por ASA-PCR con cebadores específicos para el alelo G428A y para el alelo wild type del gen FUT2. Los resultados obtenidos mostraron que el 77% de los individuos investigados fueron secretores y presentaron el fenotipo Lewis Le(a-b+). El polimorfismo G428A estuvo presente en homocigosis en un 7.5%, valor menor al reportado en la bibliografía para la población caucásica. El análisis molecular del gen FUT2 confirmaría la diversidad genética de la población investigada y podría ser utilizada como un marcador poblacional.

The secretor status is determinate by the secretor gene (FUT2) responsible of the ABH antigens expression in human secretions. About 20% of Caucasian individuals are non-secretors. The aim of this study was to study the allelic varieties of the FUT2 gene by a PCR reaction. We worked with peripheral blood samples of volunteers (n= 1728). We determinated the secretor status in plasma and saliva. The genomic DNA was extracted by an enzymatic digestion method and was analyzed by ASA-PCR with specific primers for the G428A allele and for the wild type allele of the FUT2 gene. The results obtained by serologic and molecular methods showed that the 77% of the investigate individuals were secretors. The G428A polymorphism had present in a 7.5%. The allelic varieties of the other non-secretor individuals different to the G428A might to correspond to other mutations. The molecular analysis of the FUT2 gene confirms the genetic diversity of the investigated population.

Effects of aging on antioxidant response and phagocytosis in senescent erythrocytes.

Red blood cell (RBC) aging is a complex process affected by immunological and biochemical parameters. In this work we studied the antioxidant response in RBC of different ages. We also investigated their interaction with peripheral blood monocytes. Anticoagulated blood samples from 19 O RhD+ volunteers' donors were processed. Young (Y) RBC and Senescent (Se) RBC were obtained by self-formed gradients of Percoll. The fractionation of the erythrocytes suspensions was demonstrated by statistically significant density-related changes in hematological determinations. Activities of glucose-6-phosphate dehydrogenase (G6PD), of soluble NADH-cytochrome b5 reductase (b5Rs) and membrane-bound b5R (b5Rm) were determined spectrophotometrically. The interaction between monocytes and different RBC suspensions was evaluated by the erythrophagocytosis assay. The G6PD and b5Rm activities in SeRBC were significantly lower than that observed in YRBC. No differences were found in the b5Rs of both groups. We observed an increased rate of erythrophagocytosis the SeRBC compared to YRBC. The decline in the activities of G6PD and b5Rm would indicate a decrease in the antioxidant response associated to RBC aging. These findings would signify that the oxidative changes of membrane occurring during the life span of the RBC might be relevant in the process of removal of SeRBC from the circulation.

Distribution of HLA-DRB1 alleles in Argentinean patients with Chagas' disease cardiomyopathy.

Chronic Chagas' disease occurs in a variable number of infected individuals and mainly manifests as an inflammatory cardiomyopathy that may lead to a fatal course. The factors underlying the establishment of chronic myocardial lesions are not fully understood. The study included 71 unrelated individuals serologically positive for T. cruzi. A group of 81 no related healthy individuals with neither symptoms nor previous diagnosis of Chagas' disease was studied as control group. Genomic DNA was extracted from peripheral blood using the standard salting out method and used as a template to amplify by the PCR the polymorphic second exon of the HLA-DRB1. PCR products were hybridized separately with sequence-specifics oligonucleotides (SSOP). DRB1*0409 and DRB1*1503 alleles were significantly more prevalent in seropositives (pC = 0.002, OR: 26.17 and 24.87 respectively). The prevalence of DRB1*1103 allele was statistically significant in the group control and could be associated with resistance Chagas' disease (pC = 0.026, OR: 0.19). Increased significance frequency of DRB1*1503 allele was found among cardiomyopathy patients suggesting that this antigen might be related with the genetic susceptibility to cardiac damage in these patients (pC = 0.014, OR: 9.22).

Duffy genotyping facilitates transfusion therapy.

The Duffy (FY) blood group system is clinically significant in transfusion medicine because FY antibodies are involved in hemolytic transfusion reactions and hemolytic disease of the newborn. The Fy(a) and Fy(b) antigens are encoded by the FY*A and FY*B alleles which are responsible for the Fy(a+b+), Fy(a+b-) and Fy(a-b+) phenotypes. The Fy(a-b-) phenotype is found in individuals homozygous for a silent FY*B allele, named FY*B ( ES ), which is caused by a mutation in the promoter region of FY*B that result in the loss of FY expression in the erythroid linage. The aim of the present study was to evaluate the role of FY DNA typing as a tool in transfusion compatibility testing. We studied 275 white blood donors from the city of Rosario by serological method and allele specific PCRs. We found that the 106 serologically Fy(a+b+) samples all genotyped as FY*A/FY*B (100%). Among the 94 Fy(a+b-) samples, 81 (86.2%) were FY*A/FY*A and 13 (13.8%) were FY*A/FY*B ( ES ) . Of the 75 Fy(a-b+) 67 (89.3%) were FY*B/FY*B and 8 (10.7%) were FY*B/FY*B ( ES ). No Fy(a-b-) samples were encountered. The frequencies of the FY*A, FY*B and FY*B ( ES ) alleles clearly revealed that the genetic pool analyzed is comprised of Caucasian and non-Caucasian alleles. These results showed that there is an important proportion of patients phenotyped as Fy(b-) that can be exposed to Fy(b+) blood units with no risk of alloimmunization when they carry the FY*A/FY*B ( ES ) genotype. Thus, FY genotyping allow increasing the pool of compatible units facilitating transfusion therapy and benefiting patients that require chronic transfusions.

Pérdida de la expresión antigénica ABH en pacientes con lesiones orales precancerosas y cancerosas / Loss of ABH antigenic expression in patients with precancerous and cancerous oral lesions

Los antígenos ABH, productos de la interacción de 2 sistemas genéticos, Hh y ABO, están sujetos a leyes de herencia y pueden estar localizados no sólo en los eritrocitos, sino también en la mayoría de las células humanas. El objetivo del este trabajo fue investigar la expresión de antígenos ABH en pacientes con lesiones orales premalignas y malignas orales. Se trabajó con muestras incluidas en tacos de parafina de pacientes con lesiones orales (n= 57). Los pacientes fueron clasificados en 2 grupos: a) lesiones premalignas y malignas diagnosticadas clínica y anatopatológicamente y b) lesiones benignas (n=93). Se investigaron los antígenos ABH por la técnica de inmunoadherencia específica modificada. Se utilizó la adherencia al tejido vascular como control positivo y al tejido adiposo como control negativo. Los resultados fueron semicuantificados desde adherencia fuertemente positiva a negativa. Se observó una significativa relación entre la expresión antigénica ABH y el grado de malignidad de las lesiones analizadas (P Yates= 0,005). La pérdida de reactividad ABH en los sitios de mayor invasividad tumoral se correlaciona con el grado del desarrollo del tumor, el grado histológico y su malignidad.

The ABH antigens, which are produced by the interaction of 2 genetic systems, Hh and ABO, are subjected to laws of heredity and may be located not only in the erythrocytes, but also in most of the human cells. The objective of this paper was to investigate the expression of ABH antigens in patients with premalignant and malignant oral lesions. Work was done with samples included in paraffin plugs in patients with oral lesions (n= 57). The patients were classified into 2 groups: a) clinical and anatomopathologically diagnosed premalignant and malignant lesions, and b) benign lesions (n=93). The ABH antigens were investigated by the modified specific immunoadherence technique. Adherence to the vascular tissue was used as a positive control, whereas adherence to the fat tissue was considered as a negative control. The results were semiquantified from strongly positive to negative adherence. A significant relation between the ABH antigen expression and the degree of malignancy of the analyzed lesions (P Yates= 0.005) was observed. The loss of ABH reactivity in the sites of greater tumoral invasiveness is correlated with the tumor development degree, the histological degree and its malignancy.

Distribution of the FYBES and RHCE*ce(733C>G) alleles in an Argentinean population: implications for transfusion medicine.

BACKGROUND: The understanding of the molecular bases of blood groups makes possible the identification of red cell antigens and antibodies using molecular approaches, especially when haemagglutination is of limited value. The practical application of DNA typing requires the analysis of the polymorphism and allele distribution of the blood group genes under study since genetic variability was observed among different ethnic groups. Urban populations of Argentina are assumed to have a white Caucasian European genetic component. However, historical and biological data account for the influence of other ethnic groups. In this work we analyse FY and RH blood group alleles attributed to Africans and that could have clinical implications in the immune destruction of erythrocytes. METHODS: We studied 103 white trios (father, mother and child, 309 samples) from the city of Rosario by allele specific PCRs and serological methods. The data obtained were analysed with the appropriate statistical test considering only fathers and mothers (n = 206). RESULTS: We found the presence of the FY*BES and RHCE*ce(733C>G) alleles and an elevated frequency (0.0583) for the Dce haplotype. The number of individuals with a concomitant occurrence of both alleles was significantly higher than that expected by chance. We found that 4.68% of the present gene pool is composed by alleles primarily associated with African ancestry and about 10% of the individuals carried at least one RH or FY allele that is predominantly observed among African populations. Thirteen percent of Fy(b-) subjects were FY*A/FY*BES. CONCLUSION: Taken together, the results suggest that admixture events between African slaves and European immigrants at the beginning of the 20th century made the physical characteristics of black Africans to be invisible nowadays. Considering that it was a recent historical event, the FY*BES and RHCE*ce(733C>G) alleles did not have time to become widespread but remain concentrated within families. These findings have considerable impact for typing and transfusion strategy in our population, increasing the pool of compatible units for Fy(b-) individuals requiring chronic transfusion. Possible difficulties in transfusion therapy and in genotyping could be anticipated and appropriately improved strategies devised, allowing a better management of the alloimmunization in the blood bank.

Association of leprosy with HLA-DRB1 in an Argentinean population.

BACKGROUND: Previous studies have suggested an influence of HLA molecules on the regulation of the anti Mycobacterium leprae immune response. METHODS: DNA typing of HLA-DRB1 alleles in 71 leprosy patients and 81 healthy controls was performed. Genomic DNA was extracted from peripheral blood and used as a template to amplify the polymorphic second exon of the HLA-DRB1 by the polymerase chain reaction (PCR). PCR products were hybridized separately with sequence-specific oligonucleotides. RESULTS: DRB1*1401 and DRB1*1406 alleles were significantly more prevalent in leprosy patients, whereas a decreased frequency of DRB1*0808 and DRB1*1103 alleles was found, by comparison with the group control. CONCLUSIONS: The HLA-DRB1 alleles could act alone or in combination with other genes to confer differential susceptibility and also protection to leprosy disease in endemic areas of the American continent.

The Dc(G48)e(s) haplotype is frequent among the Dce haplotypes within a white population.

BACKGROUND: The absence of hybrid Rhesus boxes denotes an RHD homozygous status and helps to detect the presence of Dce haplotypes instead of dce. RHCE exon 1 C48, characteristic of RHC alleles, and RHCE exon 5 G733, responsible for VS antigenicity, have been noted in many RHce alleles but it was not clearly established whether they occurred in the same allele and/or cosegregate together with RHD. STUDY DESIGN AND METHODS: Samples from 148 white trios (father, mother, and child) were studied. Rh phenotype was performed by hemagglutination. Hybrid Rhesus box, RHCE exon 1 G48C, RHCE exon 5 C733G, and RHC intron 2 polymorphisms were analyzed by polymerase chain reaction. Haplotypes were determined considering serologic, molecular, and segregation data. RESULTS: RHCE exon 1 C48 and RHCE exon 5 G733 were present in RHce alleles that cosegregated with RHD forming Dce haplotypes. Both transversions were not frequently found in the same RHce allele. Of the 33 Dce haplotypes, 16 (48.5%) had a C at position 48 [Dc(C48)e], 11 (33.3%) had a G at position 48 with a G at position 733 [Dc(G48)e(s)], 5 (15.2%) had a G at position 48 [Dc(G48)e], and 1 (3.0%) had a C at position 48 with a G at position 733 [Dc(C48)e(s)]. CONCLUSIONS: The results show four molecular backgrounds for the Dce haplotype and reflect the contribution of African alleles to the genetic pool of the population under study. The molecular characterization of Dce and its frequency distribution may develop a better understanding of the phylogeny of Rh haplotypes.

Expresión antigénica ABH y carácter secretor en pacientes con lesiones orales precancerosas y cancerosas / Secretor status and ABH antigens expression in patients with oral lesion

Los antígenos ABH, productos de la interacción de dos sistemas genéticos Hh y ABO, están sujetos a leyes de herencia y pueden estar localizados no sólo en los eritrocitos sino también en la mayoría de las células humanas. El objetivo del este trabajo fue investigar la relación entre el carácter secretor de pacientes con lesiones orales pre-malignas y malignas y la expresión antigénica ABH en cortes histológicos de dichas lesiones. Se trabajó con muestras incluídas en tacos de parafina de pacientes con lesiones orales. Los pacientes fueron clasificados en 2 grupos a) lesiones pre-malignas y malignas y b) lesiones benignas. Se investigaron los antígenos ABH por la técnica de inmunoadherencia específica modificada. Se utilizó la adherencia al tejido vascular como control positivo y al tejido adiposo como control negativo. Los resultados fueron semicuantificados desde adherencia fuertemente positiva a negativa. El carácter secretor fue determinado por la técnica de inhibición de la hemaglutinación. En 21 de las 34 muestras se observó una débil expresión antigénica en áreas atípicas, y deleción total en las áreas histológicamente afectadas por neoplasia. En 8 muestras hubo pérdida total de los antígenos ABH tanto en áreas normales como patológicas, estos pacientes presentaron un mayor grado de malignidad y metástasis que aquellos que conservaron la antigenicidad. Los pacientes con lesiones orales pre-malignas y malignas presentaron un incremento del carácter no secretor (52,3 por ciento) respecto de la población control (19,5 por ciento) y de aquellos pacientes con lesiones orales benignas (15.4 por ciento). Se observó una importante asociación entre pacientes no secretores y deleción de los antigenos ABH en muestras de lesiones orales. Además, hemos encontrado, en el grupo no secretor, una mayor malignidad de las lesiones orales como así también una mayor presentación de displasia epitelial. El estudio del carácter secretor en los pacientes con lesiones orales...(AU)

Expresión antigénica ABH y carácter secretor en pacientes con lesiones orales precancerosas y cancerosas / Secretor status and ABH antigens expression in patients with oral lesion

Los antígenos ABH, productos de la interacción de dos sistemas genéticos Hh y ABO, están sujetos a leyes de herencia y pueden estar localizados no sólo en los eritrocitos sino también en la mayoría de las células humanas. El objetivo del este trabajo fue investigar la relación entre el carácter secretor de pacientes con lesiones orales pre-malignas y malignas y la expresión antigénica ABH en cortes histológicos de dichas lesiones. Se trabajó con muestras incluídas en tacos de parafina de pacientes con lesiones orales. Los pacientes fueron clasificados en 2 grupos a) lesiones pre-malignas y malignas y b) lesiones benignas. Se investigaron los antígenos ABH por la técnica de inmunoadherencia específica modificada. Se utilizó la adherencia al tejido vascular como control positivo y al tejido adiposo como control negativo. Los resultados fueron semicuantificados desde adherencia fuertemente positiva a negativa. El carácter secretor fue determinado por la técnica de inhibición de la hemaglutinación. En 21 de las 34 muestras se observó una débil expresión antigénica en áreas atípicas, y deleción total en las áreas histológicamente afectadas por neoplasia. En 8 muestras hubo pérdida total de los antígenos ABH tanto en áreas normales como patológicas, estos pacientes presentaron un mayor grado de malignidad y metástasis que aquellos que conservaron la antigenicidad. Los pacientes con lesiones orales pre-malignas y malignas presentaron un incremento del carácter no secretor (52,3 por ciento) respecto de la población control (19,5 por ciento) y de aquellos pacientes con lesiones orales benignas (15.4 por ciento). Se observó una importante asociación entre pacientes no secretores y deleción de los antigenos ABH en muestras de lesiones orales. Además, hemos encontrado, en el grupo no secretor, una mayor malignidad de las lesiones orales como así también una mayor presentación de displasia epitelial. El estudio del carácter secretor en los pacientes con lesiones orales...

HLA class II DRB1 polymorphism in Argentinians undergoing chronic Trypanosoma cruzi infection.

DNA typing of human lymphocyte antigen (HLA)-dicloro-1-[beta]-D-ribofuranosyl-benzimidazole 1 (DRB1) alleles in 35 individuals serologically positive for T. cruzi and in 41 healthy controls was performed. DRB1*0409 allele was significantly more prevalent in seropositive individuals, with a trend being also observed for the DRB1*0701 and DRB1*1503 alleles. Although statistically insignificant, the latter was found more frequent in cases with cardiomyopathy.

[Alloimmunization to a high frequency Rh antigen]. / Aloinmunizacion a un antigeno del sistema Rh de alta frecuencia.

We report the case of a pregnant woman sensitized with a panreactive anti-Rh17 alloantibody. Patient's red blood cells showed a partial deletion of Rh antigens, which was responsible for the alloimmunization. An autotransfusion program was instrumented so as to cover possible demands. Molecular analysis of the RH locus showed the presence of a hybrid RHCE-D(5-7)-CE allele that gave origin to the deleted phenotype.

Aloinmunizacion a un antigeno del sistema rh de alta frecuencia / Alloimmunization to a high frequency Rh antigen

Describimos el caso de una embarazada sensibilizada con un aloanticuerpo anti-Rh17 de muy amplia reactividad. Los glóbulos rojos de la paciente presentaban una deleción parcial de los antígenos del sistema Rh, responsable de la aloinmunización encontrada. Debido a la dificultad de obtener sangre compatible se elaboró un plan de transfusión autóloga para cubrir las posibles demandas. El análisis molecular del locus RH demostró la presencia de un alelo híbrido RHCE-D(5-7)-CE que generaba el fenotipo delecionado. (AU)

Aloinmunizacion a un antigeno del sistema rh de alta frecuencia / Alloimmunization to a high frequency Rh antigen

Describimos el caso de una embarazada sensibilizada con un aloanticuerpo anti-Rh17 de muy amplia reactividad. Los glóbulos rojos de la paciente presentaban una deleción parcial de los antígenos del sistema Rh, responsable de la aloinmunización encontrada. Debido a la dificultad de obtener sangre compatible se elaboró un plan de transfusión autóloga para cubrir las posibles demandas. El análisis molecular del locus RH demostró la presencia de un alelo híbrido RHCE-D(5-7)-CE que generaba el fenotipo delecionado. (AU)

Aloinmunizacion a un antigeno del sistema rh de alta frecuencia / Alloimmunization to a high frequency Rh antigen

Describimos el caso de una embarazada sensibilizada con un aloanticuerpo anti-Rh17 de muy amplia reactividad. Los glóbulos rojos de la paciente presentaban una deleción parcial de los antígenos del sistema Rh, responsable de la aloinmunización encontrada. Debido a la dificultad de obtener sangre compatible se elaboró un plan de transfusión autóloga para cubrir las posibles demandas. El análisis molecular del locus RH demostró la presencia de un alelo híbrido RHCE-D(5-7)-CE que generaba el fenotipo delecionado.

Determinación de IgG en eritrocitos senescentes por un ensayo enzimático con consumo de antiglobulina / Determination of senescent red blood cells bound IgG using an enzyme test based an the consuption of antiglobulin

Durante el envejecimiento de los GR se acumula IgG autóloga sobre la membrana eritrocitaria. Esta IgG esta dirigida a un neo antígeno de senescencia, ubicado en la proteína banda 3. El objetivo de este trabajo fue determinar pequeñas cantidades de IgG en la membrana del GR utilizando un inmunoensayo con antiglobulina conjugada con una enzima. Las suspensiones de GRSe y GRJ fueron incubadas con anti-IgG humana conjugada con fosfatasa alcalina. Se transfirieron alícuotas a microplacas sensibilizadas con IgG humana. Se agregó el sustrato de la enzima y se midió la IgG libre. Las concentraciones de IgG unida a la membrana eritrocitaria en GRSe (13.31 x 10-4(g/(L(1.57 x 10-4) fueron significativamente mayores (p(0.0001) que los valores observados en GR (3.35 x 10-4(g/(L(1.39 x 10-4). Los resultados obtenidos indican que esta metodología constituye una herramienta útil para determinar pequeñas contidades de IgG unida a la membrana eritrocitaria.