Fetal and neonatal alloimmune thrombocytopenia: a late or missed diagnosis disease in fetal and perinatal health-care settings.

INTRODUCTION: Even though Fetal and Neonatal Alloimmune Thrombocytopenia (FNAIT) has been recognized as the main cause of primary hemorrhagic morbidity and mortality in fetuses and newborns, screening programs to detect pregnancies at risk have not yet been implemented in any country. Moreover, in spite of increased concerns about maternal, fetal and neonatal health care in general, this potentially lethal disease is still underdiagnosed. The aim of this report is to highlight the importance of considering FNAIT in fetal and perinatal health-care settings and show the usefulness of molecular tools in early diagnosis of this clinical entity. METHODS: DNA was extracted from whole blood from parents and newborns; genotyping was performed by in house PCR using sequence-specific primers for typing Human Platelet Antigens (HPA)-1 to -6, -9, and -15, and with commercial HPA-TYPE (BAG HealthCare, Lich, Germany). Anti-HPA antibodies in the maternal serum were detected by the Monoclonal Antibody Solid Phase Platelet antibody Test (MASPAT). Chloroquine-treated platelets were used for the discrimination of platelet-specific antibodies from anti-HLA antibodies. RESULTS: Patients 1 and 2 had severe thrombocytopenia due to incompatibility in HPA-1 and HPA-15, respectively. The third case was a thrombocytopenic neonate with severe bleeding complications other than ICH and in whom differential diagnosis between FNAIT and Von Willebrand congenital disease was necessary; incompatibility in HPA-15 was also demonstrated. Case 4 represents a missed diagnostic opportunity. CONCLUSION: This is the first report of FNAIT cases confirmed by molecular evidence and anti-HPA antibodies detection in Argentina. This report reinforces the relevance of early diagnosis of this clinical entity. Since the delay in FNAIT diagnosis could lead to severe consequences in the fetus and neonates, strategies to approach maternal, fetal, and perinatal health, as well as prevention policies aimed to reduce fetal and neonatal morbidity and mortality should focus on implementing programs to identify high-risk pregnancies and thus reduce thrombocytopenia-related complications in fetuses and newborns.

Usefulness of Non-Invasive Fetal RHD Genotyping towards Immunoprophylaxis Optimization.

Introduction: Since anti-D immunoprophylaxis given to D-negative pregnant women is a blood product, blood donations have an impact on the availability of prophylactic doses. The Pan American Health Organization reported, in June 2017, that less than half of blood donors are volunteers in Latin America and the Caribbean. In these countries, guidelines for use of anti-D prophylaxis are still controversial. The aim of this study was to demonstrate the convenience of a simple and cost-effectivene non-invasive prenatal diagnostic assay for anti-D prophylaxis optimization in multiethnic populations. Methods: Cell-free fetal DNA from plasma samples of D-negative pregnant women were analyzed by real-time PCR for simultaneous amplification of sequences of exons 5 and 10 of the RHD gene. Fetal RHD genotype was determined in 111 pregnant women. Neonates' phenotype was determined 72 h after birth. Results: Genotyping predicted fetal phenotype with 100% accuracy. Prenatal diagnosis showed 78% RHD-positive and 22% RHD-negative neonates. Conclusion: We demonstrated that, beyond the large genetic variation of the Rh system and the numerous D variants present in multiethnic groups, non-invasive fetal RHD genotyping using two sequences of the gene can be enough for clinical application in an admixed population. This robust technique of simple implementation allows to determine fetal RHD in maternal blood with high sensitivity, specificity, and accuracy. The introduction of fetal RhD genotyping as part of an antenatal screening program constitutes a reliable manner to optimize anti-D prophylaxis; however, it has not been implemented so far in most American countries.

Transfusión intrauterina por cordocentesis: efectos adversos inmunohematológicos e impacto en el neonato / Introuterine transfusion by cordocentesis: adverse immunohematological effects and impact on the newborn

Objetivos: Evaluar las complicaciones inmunohematológicas producidas por las madres sensibilizadas que son sometidas a transfusión intrauterina (TIU) y su impacto en el recién nacido (RN). Materiales y métodos: Se realizó un trabajo retrospectivo que incluyó 22 pacientes (ptes) de alto riesgo (20 con anti D, 1 anti C y 1 anti E) a las que se les realizaron tratamiento con TIU, los datos se obtuvieron de la historia clínica de la madre, del RN y fichas inmunohematológicas del servicio de medicina transfusional, a las pacientes se le realizaron controles inmuno - hematológicos en la primera consulta y luego cada 15 días hasta finalizar el embarazo lo que incluyó titulación más dosaje ponderal de anticuerpo, luego cada dos TIU se realizó panel identificador. Resultados: Del total de las ptes; 3 desarrollaron nuevos ac. después del 4° procedimiento, en dos pacientes se sumó un anticuerpo (Ac) y una pte formó 2. Al determinar la causa probable de la formación de dichos Ac se encontró: Un anti C que fue asociado al pasaje de sangre fetal a la madre, un anti Kell a los GR transfundidos, y en los ac anti c y Jka no se pudo dilucidar su origen. El 73% de las ptes elevó los títulos después de las TIU. La relación entre aumento de títulos y n° de TIU fue del 31% posterior a la 1a., el 56% a la 2a., 13% a la 3a. o más. El 69% de las ptes aumentó los títulos una única vez, independientemente del número de punciones y el 31 % ascendió con cada estímulo. En 9 ptes las TIU fueron transplacentarias y todas ellas elevaron los títulos de Ac; en las 13 no transplacentarias solo 7 aumentaron. Del total de RN, 52% tuvo como complicación anemia tadía un 19% recibió exanguíneotransfusión y el resto sin complicación. El dosaje ponderal de Ac se elevó más que los títulos en los casos de mayor afección en RN. Conclusión: Las complicaciones inmunohematológicas por TIU son frecuentes y pueden afectar el futuro obstétrico y transfusional de la madre... (TRUNCADO)

Objectives: Assess the immunohematological complications intrauterine transfusion (lUT) produced in sensitized mothers and its impact on the new born (NB). Materials and methods: A retrospective study was carried out, including 22 high risk patients (20 with anti-­D antibodies, 1 with anti-c antibodies and 1 with anti-E antibodies) which underwent percutaneous umbilical cord blood transfusion (or IUT), the data were obtained from the mothers and the newborns clinical chart as well as immunohematological record cards of the transfusion medicine department. Imunohematological testing including antibody titre and ponderal antibody quantitation was carried out at each patients first ap pointment and thenceforward every two weeks until the end of pregnancy, and cell panel antibody screening after every second IUT. Results: Out of the total of 22 patients; 3 developed new antibodies following the 4th procedure, two patients added one new antibody and one patient formed two antibodies. When determining the probable cause for these antibodies, the following was found: in one case an Anti-C antibody was linked to fetal-to-maternal hemorrhage, an anti-Kell antibody as reponse to antigens from the transfused red cells; and the origin of an anti-c antibody and an anti-Jka could not be explained. Increased antibody titre after IUT was found in 73% of the patients. Increase of titre regarding number of IUTs: 31% following the first procedure, 56% after the second and 13% after 3 or more procedures. Aside from the number of IUTs, in 69% of the cases the titre increased only once, while 31% of the patients suffered increase with each antigenic stimulus. Antibody titre increased in all 9 patients that under­went transplacental IUT; while only 7 of the 13 nontransplacental cases did. Late onset anemia occured in 52% of the newborns, and 19% required exsanguinotransfusion. The rest did not have any complication... (TRUNCADO)

Score Delphos 1: estimación del grado de afectación fetal en enfermedad hemolítica del recién nacido / Delphos I Score: estimation of the degree of fetal affectation in haemolytic disease of the newborn

Objetivos: Realizar un modelo de score de riesgo en pacientes sensibilizadas. Predecir el comportamiento futuro e identificar la población con mayor probabilidad de complicaciones feto-neonatales. Métodos: Se realizó un modelo de score de riesgo, DELPHOS l. Se analizaron las fichas inmunohematológicas de 91 pacientes embarazadas sensibilizadas en el período 1999-2008. Se incluyeron: pacientes puérperas, sensibilizadas a anticuerpos anti D solo o asociado a otro productor de enfermedad hemolítica (EH), parto o cesárea con recién nacido en este hospital. Se excluyeron: pacientes embarazadas, sensibilizadas a anticuerpos no productores de EH, pacientes con recién nacido derivado a otro nosocomio. Para su construcción se confeccionó una tabla valorando: antecedentes obstétricos, edad gestacional, titulo, tipo, número de anticuerpos y causas de incremento del título de anticuerpos. Se dio a cada punto citado un puntaje mínimo y máximo. Se procedió al ensayo del mismo comparando la puntuación obtenida con la evolución del feto/neonato en cada caso. Resultados: El 66% de las pacientes consultaron antes de la semana 25 de embarazo presentando score más alto respecto a las que consultaron a las 25 semanas o más. El número de recién nacidos Rh positivos no afectados fue mayor hasta el score 5; a partir de este, aumentó el número y la gravedad de la afectación. Las pacientes sometidas a transfusión intrauterina (TIU) fueron aquellas con score igual o mayor a 6. Por lo tanto el score 6 resultó ser punto de corte a partir del cual se incrementó la afectación feto-neonatal. Conclusión: Un modelo de score permitiría simplificar y mejorar la elección de la conducta a tomar frente a pacientes sensibilizadas.

Objectives: Create a score model to assess risk in sensitized patients. Predict future behaviour and identify the population with higher probability of fetal and neonatal complications. Methods: A risk score model was created, DELPHOS l. The immunohematological record cards of 91 sensitized pregnant patients (1999 through 2008) were surveyed. The following were included: sensitized puerperal patients with anti-D as sole causing antibody or associated to another Haemolytic Disease (HD)-producing antibody, vaginal birth or Caesarean section, with their newborn still in this hospital. The following were excluded: pregnant patients, sensitization by non HD­-producing antibodies, patients with newborn sent to other healthcare facilities. For its construction, a chart was designed evaluating: obstetric medical records, gestational age, titre, type, number of antibodies and causes for antibody increase. A minimum and maximum number of points was assigned to each of the mentioned criteria. A test run was carried out, comparing the obtained number of points with the clinical status of the fetus/newborn in each case. Results: 66% of the patients consulted before 25 weeks pregnancy exhibiting higher scores; as opposed to those that consulted at 25 or more weeks pregnancy. The number of non-affected Rh-positive newborns was higher, up until score 5; from that point on, the number and severeness of affectation increased. The patients to undergo intra-uterine transfusion, were those with score 6 or higher. Therefore score 6 turned out to be the breaking-point starting from which, the fetal/neonatal affectation increased. Conclusion: A score model would allow to simplify and improve the course of action in the management of sensitized patients.