Obtención de plasma rico en plaquetas (PRP) en el Laboratorio de Terapia Celular para uso como herramienta terapéutica en medicina regenerativa / Obtaining platelet rich plasma (PRP) in the Cell Therapy Laboratory for use as a therapeutic tool in regenerative medicine

Platelet rich plasma (PRP) is used to speed up tissue repair. Despite its widespread use, the therapeutic application of PRP generates controversies in clinical results due to the variability in methods of obtaining the different preparations and differences between the components of different types of PRP, so it's recommended to mention the type of platelet preparation used. In this article, we describe technical and biologics characteristics of our platelet product, and we compare them to different commercial preparations described in order to validate their clinical use. Our results determine that the preparation can be considered a platelet rich plasma with biological activity in vivo and in vitro, which supports its use as a valid therapeutic tool, alternative to products currently available in Regenerative Medicine. (AU)

Estandarización de la técnica Real Time PCR para la detección molecular de la mutación V617F en el gen de JAK-2 en neoplasias mieloproliferativas crónicas / Standardization of the Real Time PCR technique for the molecular detection of the V617F mutation in the JAK-2 gene in chronic myeloproliferative neoplasms

V617F mutation in exon 14 of Janus Kinase 2 gene (jak-2) is used as a molecular marker for the diagnosis of Philadelphia negative myeloproliferative neoplasms (Phi-) such as Polycythemia Vera (PV), Essential Thrombocythemia (ET) and Primary Myelofibrosis (MFP). To detect this mutation, we used conventional polymerase chain reaction technique (PCR), a simple and inexpensive technique, however, has some drawbacks that current technology allows to solve. During the last years, more sensitive molecular techniques have been incorporated in clinical practice to support the diagnosis, prognosis and follow-up of hematological patients. For its implementation in the clinical routine should be considered technical and economic aspects, so in this work, we evaluate the Real Time PCR technique as a diagnostic method for the detection of the Jak-2-V617F mutation, using in house primers design. Our result show that the technique implemented has a concordance index of 0.87 with the conventional PCR used in the molecular diagnosis of myeloproliferative neoplasms. In addition, it has the same specificity, greater sensitivity and, shorter execution time in relation to conventional PCR. The implementation of this diagnostic method in our Hospital is technically possible and commercially convenient. (AU)

Influencia del polimorfismo genético rs2927488 de Bcl3 en el síndrome de intestino irritable / Influence of genetic polymorphism rs2927488 of the Bcl3 irritable bowel syndrome

Irritable Bowel Syndrome (IBS) is a functional disorder characterized by abdominal discomfort associated with changes in bowel habit and increased intestinal sensitivity. It is one of the most common disorders of digestive health in Chile as well as in the world. Although the pathophysiological mechanisms of IBS have yet to be fully established, it is known that (epi-) genetic factors are involved in the development of the disorder. Bcl3 (B-cell leukemia/lymphoma 3) is a regulatory protein of the intestinal inflammatory response, specifically, with regard to the signaling pathways of NF-kB (Nuclear Factor-kB). Among the variability of the human genome, the gene encoding Bcl3 contains the polymorphism SNPs rs2927488 (variants A/G) which has been associated with susceptibility to developing Inflammatory Bowel Disease (IBD). Furthermore, the presence of this polymorphic variant has been correlated with increased levels of Bcl3 gene expression in patients with Crohn’s Disease. Our laboratory is focused on understanding the potential relationship between Bcl3 and IBS. Our preliminary studies describe an increased expression of Bcl3 at the intestinal mucosal epithelium in IBS patients with a diarrheal-phenotype (IBS-D). We are now interested to investigate if the presence of the variant SNP rs2927488(A/G) is a susceptibility factor for IBS development and to understand the significance of its relationship with Bcl3 expression, in Chilean IBS patients. In this review, we focus primarily on the relationship between rs2927488(A/G) polymorphism of Bcl3 gene, its protein expression and its mechanisms of control over the inflammatory response...

Frecuencia génica de antígenos menores de histocompatibilidad en la población chilena y estimación de sus efectos inmunológicos en el trasplante alogénico de progenitores hematopoyéticos / Frequency of minor histocompatibility antigens among Chilean blood donors

Background: Minor histocompatibility antigens (mHAgs) play a critical role in the immune responses associated with allogeneic stem cell transplantation, such as graft versus host disease (GVHD) and graft-versus-tumor (GVT). Aim: To determine the gene frequencies of the mHAgs HA-1, HA-2 and HA-8 in Chilean Blood Bank donors. Material and Methods: Blood from 192 blood donors was analyzed. The presence of haplotype HLA-A*02 was determined by flow cytometry. The frequency of mHAgs was determined by allele specific polymerase chain reaction in genomic DNA. Results: Sixty one participants were carriers of the haplotype HLA-A*02. The relative allele frequency HA-1H was 45%, HA-Ir 55%, HA-2V 80.6%, HA-2M 19.4%, HA-8R 49.8% and HA-8P was 50.2%. Based on mHAgs disparity between HA-1, HA-2 or HA-8, the probability to generate a GVT response in HLA-A*02 individuals was 40%. Conclusions: The mHAgs frequency in Chilean population is under Hardy-Weinberg equilibrium and they are similar to those of other ethnic populations in the world.

Respuesta inmune contra antígenos menores de histocompatibilidad en el trasplante alogénico de progenitores hematopoyéticos / Immunologycal response under antigens hematopoietic stem cell transplantation

Patients who receive allo hematopoietic stem cell transplantation (SCT) could develop graft versus host disease and/or graft versus tumour effect. These immunological responses can happen even with perfect fully HLA matched haematopoietic stem cells. Moreover, the engraftment of the donor’s cells depends on the immunological conditions of both donor and recipient. The development of alloreactivity occurs in the context of the polymorphisms of the human genome, these genomic differences results in proteins with antigenic properties which trigger immune responses. Considering this, the SCT is a powerful tool to heal the patient disease, because all of them become chimeras. In other words, into individuals with two different genomic sets, which will develop a strong immunological response that cannot exist in natural conditions.

Estudio de quimerismo: aplicación en pacientes con trasplante de progenitores hematopoyéticos / Chimerism study: application in patients with allogeneic progenitor cell transplantation

El trasplante alogénico de progenitores hematopoyéticos (TAPH) es una técnica que ha cambiado el pronóstico de muchas enfermedades hematológicas malignas y no malignas. En determinados tiempos post trasplante coexisten células hematológicas de receptor y dador, por lo cual el individuo posee dos sistemas hematopoyéticos. El término Quimera se utiliza para indicar el origen dual de las células hematológicas. Este análisis es indispensable para saber si existe prendimiento o rechazo del trasplante. La determinación de quimerismo se realiza mediante la amplificación por PCR de secuencias cortas repetidas tandem (STRs del ingles short tandem repeat sequence). Este examen es fácil de realizar, reproducible, altamente sensible y específico. El resultado del quimerismo es de vital importancia a la hora de tomar decisiones clínicas, sobre todo si se utilizan técnicas no mieloablativas de acondicionamiento, infusión de linfocitos del donante, o modificaciones en los protocolos de inmunosupresión, donde existe una lata variabilidad en el prendimiento del injerto y el desarrollo de enfermedad de injerto contra huésped (EICH) e injerto contra tumor (ICT).

Allogeneic progenitor cell transplantation (ALoPCT) is a procedure that has changed the prognosis of many malignant and non-malignant hematologic diseases. For a period of time post-trasplant, cellular subtypes from the donor and the host coexist, giving the patient two hematopoietic systems. The term Chimera is used to indicate the dual origin of blood cells. This analysis is important to determine whether engrafment or rejection has occurred. The determination of chimerism is based on PCR pf Short Tandem Repeat sequences (STRs). The PCR technique is easy to perform, reproducible, highly sensitive and specific. Chimerism determination helps to improve the clinical approach to the patient, specifically when non-mieloablative conditioning, lymphocyte donor infusion or modification of the immunosuppressive protocols have employed. All of these manipulations produce a high variability in engraftment, development of graft versus host disease (GVHD) and the likelihood to eliminate tumor cells through graft versus tumor (GVT) effects.