[Obtaining blood components in blood banks]. / Obtención de componentes sanguíneos en los bancos de sangre.

After the first successful blood transfusion, different difficulties of a liquid tissue were overcome; this liquid required special conditions to keep its characteristics with minimal alterations and, thus, to be able to be used in patients who needed it. Subsequently, techniques that also made possible to separate this liquid into its different components for its use were discovered, allowing a more specific treatment of the deficiencies of patients when administering cellular or non-cellular elements. With this, a new area arose within the blood banks to obtaining components. This area became the central point of convergence of all the processes involved in obtaining components, which include the biological qualification of each one of the units, as well as their labeling and release for the different distribution in transfusion services. It is important to highlight that the main source of components is obtained from whole blood; its processing for several decades was an artisanal operator-dependent process; however, with the evolution of technology, now it is possible to carry it out in an automated manner; likewise, today it is possible to obtain components directly from the donor's whole blood by separating it in real time by means of apheresis, which allows obtaining the component of interest and returning the remainder to the donor.

Tras la primera transfusión de sangre exitosa, se fueron superando diferentes dificultades de un tejido líquido que fue requiriendo condiciones especiales para mantener sus características con mínimas alteraciones y así pudiera ser utilizado en los pacientes que lo necesitaran. Posteriormente, se descubrieron técnicas que además posibilitaban separar este líquido en sus diferentes componentes para su empleo, lo cual permitió tratar de manera más específica las deficiencias de los pacientes al administrar los elementos celulares o acelulares. Con esto surgió dentro de los bancos de sangre el área de obtención de componentes. Esta se convirtió en el punto central de convergencia de todos los procesos involucrados en la obtención de componentes, que incluyen la calificación biológica de cada una de las unidades, así como su etiquetado y liberación para la distribución en los diferentes servicios de transfusión. Es importante resaltar que la principal fuente de componentes se obtienen por sangre total; su procesamiento durante varias décadas era un proceso artesanal con operador dependiente, pero con la evolución de la tecnología actualmente es posible llevarla a cabo de manera automatizada; asimismo, es posible obtener componentes directamente de la sangre total del donador por medio de la separación de la misma en tiempo real por medio de aféresis, la cual permite obtener el componente de interés, con lo que se devuelve el remanente al donador.

Genetic diversity of HLA system in two populations from Chiapas, Mexico: Tuxtla Gutiérrez and rural Chiapas.

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 173 Mexicans from the state of Chiapas living in the city of Tuxtla Gutiérrez (N = 52) and rural communities (N = 121), to obtain information regarding allelic and haplotypic frequencies. We found that the most frequent haplotypes in Chiapas include 12 Native American and one European haplotype. Admixture estimates revealed that the main genetic components in Chiapas are Native American (71.61 ±â€¯0.58% by ML; 53.16% of Native American haplotypes) and European (26.39 ±â€¯5.05% by ML; 25.86% of European haplotypes), and a less prominent African genetic component (2.00 ±â€¯5.20% by ML; 9.77% of African haplotypes).

Genetic diversity of HLA system in two populations from Hidalgo, Mexico: Pachuca and rural Hidalgo.

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 122 Mexicans from the state of Hidalgo living in the city of Pachuca (N = 41) and rural communities (N = 81), to obtain information regarding allelic and haplotypic frequencies. We find that the most frequent haplotypes in Hidalgo include eight Native American and one European haplotypes. Admixture estimates revealed that the main genetic components in Hidalgo are Native American (58.93 ±â€¯2.16% by ML; 54.51% of Native American haplotypes) and European (32.49 ±â€¯2.88% by ML; 28.69% of European haplotypes), and a relatively high African genetic component (8.58 ±â€¯0.93% by ML; 6.97% of African haplotypes).

Genetic diversity of HLA system in two populations from Morelos, Mexico: Cuernavaca and rural Morelos.

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 112 Mexicans from the state of Morelos living in the city of Cuernavaca (N = 82) and rural communities (N = 30), to obtain information regarding allelic and haplotypic frequencies. The most frequent haplotypes in Morelos include seven Native American, one European, one African and one Asian haplotype. Admixture estimates revealed that the main genetic components in Morelos are Native American (60.43 ±â€¯2.22% by ML; 53.57% of Native American haplotypes) and European (39.58 ±â€¯3.70% by ML; 27.68% of European haplotypes), and a virtually absent African genetic component (0.00 ±â€¯4.93% by ML; but 11.16% of African haplotypes).

Genetic diversity of HLA system in six populations from Mexico City Metropolitan Area, Mexico: Mexico City North, Mexico City South, Mexico City East, Mexico City West, Mexico City Center and rural Mexico City.

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 1217 Mexicans from the Mexico City Metropolitan Area living in the northern (N = 751), southern (N = 52), eastern (N = 79), western (N = 33), and central (N = 152) Mexico City, and rural communities (N = 150), to obtain information regarding allelic and haplotypic frequencies. We found that the most frequent haplotypes include 11 Native American haplotypes. Admixture estimates revealed that the main genetic components are Native American (63.85 ±â€¯1.55% by ML; 57.19% of Native American haplotypes) and European (28.53 ±â€¯3.13% by ML; 28.40% of European haplotypes), and a less apparent African genetic component (7.61 ±â€¯1.96% by ML; 7.17% of African haplotypes).

Blood safety in Mexico and a perspective on Latin America.

Blood safety has been of paramount concern worldwide over the last decades, and Latin America and Mexico are no exception. Factors of utmost importance include the use of highly efficient screening tests and the encouragement of voluntary donation. This review summarizes the current situation in Latin America and particularly in Mexico with respect to these key issues. Except for some specific regions, there is a lack of progress of voluntary donation in Mexico compared with other Latin American countries. A more efficient voluntary donation system could provide donors with lower prevalence of infectious agents such as human immunodeficiency, hepatitis B, and hepatitis C viruses. In Latin America, and specifically in countries such as Argentina, Brazil and Nicaragua, voluntary donation and blood safety are strongly encouraged. However, to date, in Mexico there has not been a specific blood safety project because of fragmentation of the health system model with structural differences among organisations. Although national policies are established to grant health coverages in Mexico, blood safety is still limited and outdated because of oversights in technical fields and regulations. Individual molecular biological tests for donor screening have recently been incorporated into the Mexican national regulations. Although the routine use of these tests as part of effective donor screening is still not compulsory, it is enabling a progressive improvement of blood safety.

HLA concordance between hematopoietic stem cell transplantation patients and umbilical cord blood units: Implications for cord blood banking in admixed populations.

Umbilical cord blood stem cell transplantation is an important choice for treating a variety of hematopoietic, neoplastic, and genetic disorders. The optimal size for a cord blood bank to provide matching units for 80% of patients requiring a stem cell transplantation procedure depends on the particular characteristics of each population. In this study, we analyzed the immunogenetic diversity of a sample set of Mexican patients suffering from blood, hematopoietic, and immunological diseases, to assess the best strategy for cord blood banking. For achieving that, we analyzed HLA-A, HLA-B, HLA-DRB1, and HLA-DQB1 genotype and allele frequencies of both units from the bioarchive of the Umbilical Cord Blood Bank from La Raza and patients requiring a stem cell transplant and compared these variables with data from the same geographic and genetic context. We were able to detect significant differences for at least half of the alleles were observed for HLA class I and class II genes between units and patients. Five Native American haplotypes had lower frequencies in patients sample than in the cord blood units. Genetic admixture estimations for both groups showed a higher contribution of Native American component in the cord blood units. Differences in ancestral components in the Umbilical Cord Blood Bank from La Raza and six virtual banks modeled from a pool of Mexican mixed ancestry individuals show that genetic background is important in cord blood collection. In conclusion, increasing diversity over quantity of new cord blood units will improve the cost effectiveness of cord blood banking and health policies regarding hematopoietic stem cell transplantation in admixed populations such as those present in Latin American countries.

[Excessive spending by misuse of clinical laboratory]. / Gasto excesivo por uso inadecuado del laboratorio clínico.

Seventy five percent or more of a diagnosis comes from a proper medical history along with an excellent physical examination. This leaves to the clinical laboratory the function of supporting the findings, determining prognosis, classifying the diseases, monitoring the diseases and, in the minimum of cases, establishing the diagnosis. In recent years there has been a global phenomenon in which the allocation of resources to health care has grown in an excessive way; the Instituto Mexicano del Seguro Social is not an exception with an increase of 29 % from 2009 to 2011; therefore, it is necessary to set containment and reduction without compromising the quality of patient care.

El 75 % o más del diagnóstico de una entidad nosológica proviene de una adecuada historia clínica junto con una exhaustiva exploración física, lo cual le deja al laboratorio clínico la función de apoyar los hallazgos, establecer pronóstico, clasificar una enfermedad, dar seguimiento y establecer en el mínimo de los casos un diagnóstico. En los últimos años se ha presentado un fenómeno global en el que la erogación de recursos para la atención a la salud ha aumentado de forma desmedida y el Instituto Mexicano del Seguro Social no ha sido la excepción con un aumento del 29 % del 2009 al 2011, por lo que es necesario el establecimiento de medidas de contención y reducción sin que se comprometa la calidad de la atención a los pacientes.

Cost-Effectiveness of Blood Donation Screening for Trypanosoma cruzi in Mexico.

An estimated 2 million inhabitants are infected with Chagas disease in Mexico, with highest prevalence coinciding with highest demographic density in the southern half of the country. After vector-borne transmission, Trypanosoma cruzi is principally transmitted to humans via blood transfusion. Despite initiation of serological screening of blood donations or donors for T. cruzi since 1990 in most Latin American countries, Mexico only finally included mandatory serological screening nationwide in official Norms in 2012. Most recent regulatory changes and segmented blood services in Mexico may affect compliance of mandatory screening guidelines. The objective of this study was to calculate the incremental cost-effectiveness ratio for total compliance of current guidelines from both Mexican primary healthcare and regular salaried worker health service institutions: the Secretary of Health and the Mexican Institute for Social Security. We developed a bi-modular model to analyze compliance using a decision tree for the most common screening algorithms for each health institution, and a Markov transition model for the natural history of illness and care. The incremental cost effectiveness ratio based on life-years gained is US$ 383 for the Secretary of Health, while the cost for an additional life-year gained is US$ 463 for the Social Security Institute. The results of the present study suggest that due to incomplete compliance of Mexico's national legislation during 2013 and 2014, the MoH has failed to confirm 15,162 T. cruzi infections, has not prevented 2,347 avoidable infections, and has lost 333,483 life-years. Although there is a vast difference in T. cruzi prevalence between Bolivia and Mexico, Bolivia established mandatory blood screening for T.cruzi in 1996 and until 2002 detected and discarded 11,489 T. cruzi -infected blood units and prevented 2,879 potential infections with their transfusion blood screening program. In the first two years of Mexico's mandated program, the two primary institutions failed to prevent due to incomplete compliance more potential infections than those gained from the first five years of Bolivia's program. Full regulatory compliance should be clearly understood as mandatory for the sake of blood security, and its monitoring and analysis in Mexico should be part of the health authority's responsibility.

Cord blood banking and transplantation at the Mexican Institute of Social Security: the first 5 years.

BACKGROUND: In January 2005, the Cord Blood Bank (CBB) at the Mexican Institute of Social Security initiated activities. Herein, we describe the experience generated during this period (January 1, 2005-December 31, 2009). STUDY DESIGN AND METHODS: Good manufacturing practices and standard operating procedures were used to address donor selection, as well as umbilical cord blood (UCB) collection, processing, and cryopreservation. Based mainly on HLA and nucleated cell content, specific UCB units were thawed, processed, and released for transplantation. RESULTS: A total of 589 UCB units were stored, representing 54% of the total number of units collected. Forty-eight units (8.14% of the stored units) were released for transplantation of 36 patients. Twenty-six patients (72% of cases) corresponded to patients with acute leukemia, five (14%) to patients with marrow failure, and the rest (five; 14%) to patients with hemoglobinopathies and other syndromes. The median number of nucleated cells infused per patient was 6.71 × 10(7) /kg and the median number of CD34+ cells was 4.8 × 10(5) /kg. Current engraftment data indicate that engraftment occurred in 56%, and no engraftment in 44%, of cases. Engraftment was more frequent (59%) in patients that received more than 3 × 10(7) total nucleated cells (TNCs)/kg body weight, than in those receiving fewer than 3 × 10(7) TNCs/kg (40%). Myeloid engraftment was observed 7 to 54 days posttransplant (median, 23 days), whereas platelet engraftment was detected on Days 12 to 87 posttransplant (median, 38 days). To date, the disease-free survival rate was 41% and the overall survival was 47%, with survival periods of 126 to 1654 days. CONCLUSION: Although the experience presented herein is still limited and the period of analysis is still short, the results obtained during these 5 years are encouraging.

[Detection of Trypanosoma cruzi in blood donors]. / Detección de Tripanosoma cruzi en donadores de sangre.

BACKGROUND: The American trypanosomiasis is the second parasitic disease in importance after paludism and one of the main mechanism of transmission is a blood transfusion. Our objective was to measure the effect the Tripanosoma Cruzi screening test in blood banks in the Mexican Institute of Social Security. METHODS: Information was obtained from each unit of blood collected. The Tripanosoma cruzi prevalence was calculated only in samples with double reactivity in the blood banks. RESULTS: Of 71 blood banks, only 26 had been doing T. Cruzi screen; after implementation of integrated services 55 are doing the screening. There were 935 donors with double reactivity to the T. Cruzi test from 230,074 samples. The national prevalence was 0.406%. The seroprevalence was 0.013% to 3.118%. CONCLUSIONS: The screening of the T. cruzi improved the detection and increased the safety and the prevention of its transmission by blood transfusion.

[Two different techniques for volume blood reduction obtained from umbilical cord]. / Dos técnicas para reducir el volumen de sangre obtenida de cordón umbilical.

BACKGROUND: To preserve the umbilical cord blood (UCB), the volume containing the cells must be reduced before freezing, but the quality, quantity and functionality of the cells has to be preserved during this procedure. The aim is to compare the performance of two different techniques for volume reduction. METHODS: A semiautomatic system and an automatic system were compared as two different UCB volume reduction techniques. Total nucleated cell (TNC) counts and viability were measured before and after volume reduction. The CD34+ cell counts also were measured. RESULTS: Seventy units of cord blood cells (UCB) were collected. Thirty-three volume reduction procedures were performed by semiautomatic system and thirty-seven by automatic system. The volume recovered and the CD34+ count in both techniques was similar, although the viability differed slightly (1% higher by Optipress II). CONCLUSIONS: The semiautomatic and automatic techniques are suitable to reduce volumes of UCB units.

Prevalence and risk factors of hepatitis C virus, hepatitis B virus, and human immunodeficiency virus in multiply transfused recipients in Mexico.

BACKGROUND: Transfusion-transmitted viral infection (TTI) is a major problem in patients receiving blood products. Monitoring high-risk patients is essential for assessing the epidemiology of blood-borne infections. STUDY DESIGN AND METHODS: A 1-year, cross-sectional seroprevalence study in patients with a history of multiple transfusions was conducted. Peripheral blood samples were titered to detect serologic markers of human immunodeficiency virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV). The presence of these viruses and demographic, behavioral, and medical traits were assessed. RESULTS: A total of 300 male and female multiply transfused patients with a mean age of 30.7 (+/-17.5) years were studied. The prevalence was 13.7% for HCV, 7% for HBV, and 1.7% for HIV. Patients with hemophilia had the highest prevalence for HCV and HIV infections, and hemodialyzed patients, for HBV infection. The risk factors related to acquired HCV were hemophilia (odds ratio [OR], 5.6; 95% confidence interval [CI], 2.5-12.6), more than five hospitalizations (OR, 3.8; 95% CI, 1.6-8.9), and having received a transfusion before mandatory screening in 1993 (OR, 8.4; 95% CI, 2.0-34.6), and for HIV, having received a transfusion before 1987 (OR, 19.0; 95% CI, 2.0-177.7). The main risk factors for HBV were having end-stage renal disease and being treated with hemodialysis (OR, 3.7; 95% CI, 1.4-9.9) and transplantation (OR, 4.2; 95% CI, 1.4-12.1). CONCLUSIONS: This study showed that HCV infection was more frequently identified than HBV and HIV infections in multiply transfused Mexican patients. Additionally, several risk factors are associated with TTI such as mandatory screenings before 1987 and 1993, which were the most important for HIV and HCV infections but not for HBV.

Establishing a cord blood banking and transplantation program in Mexico: a single institution experience.

BACKGROUND: Over the past decade, umbilical cord blood (UCB) banking and transplantation have increased significantly worldwide. The experience in developing countries, however, is still limited. In January 2005 the Mexican Institute of Social Security (IMSS) initiated its UCB banking and transplantation program. This study reports on the experience generated at this institution during the first 2 years of activities. STUDY DESIGN AND METHODS: A public UCB bank was established at La Raza Medical Center, IMSS, in Mexico City. Good manufacturing practices and standard operating procedures were used to address donor selection, as well as UCB collection, processing, and cryopreservation. Based mainly on human leukocyte antigen (HLA) and total nucleated cell (TNC) content, specific UCB units were thawed, processed, and released for transplantation. RESULTS: Based on stringent selection criteria, 360 UCB units were collected from January 2005 to December 2006. A total of 201 (56%) units (minimum volume, 50 mL without anticoagulant) were processed and stored. Median values for specific parameters were as follows: volume, 89.9 mL; viability, 94.8%; TNCs, 0.91 x 10(9); CD34+ cells, 3.13 x 10(6); and colony-forming cells, 1.20 x 10(6). During this period, 10 units had been released for transplantation to seven patients (six children and one adult). Engraftment was observed in five patients; four of them were still in remission (114-293 days after transplant). In spite of showing sustained engraftment, one patient died on Day +88. Two patients showed no engraftment and died 29 to 30 days after transplant. CONCLUSION: The results obtained during this initial period are encouraging and indicate that the UCB banking and transplantation program at IMSS will help to improve already existing hematopoietic cell transplant programs in Mexico. The experience generated at IMSS may be helpful to other institutions, particularly those in developing countries.

[Prevalence of hepatitis C virus in the blood bank at Centro Médico Nacional La Raza]. / Prevalencia del virus de hepatitis C en el Banco de Sangre del Centro Médico Nacional La Raza.

INTRODUCTION: There are no records on the prevalence of infection by HCV in Mexican population. The central area of Mexico is a highly dense demographic zone and is the influence area of the second blood bank in Latin America in terms of affluence. MATERIAL AND METHODS: We prospectively studied the prevalence and genotypes of HCV infection in 5105 individuals attending the Central Blood Bank of Centro Médico Nacional La Raza regardless if they were accepted or rejected as donors. We applied a quimiolumiscence assay as a screening test. A recombinant immunoassay (RIBA) and a qualitative polymerase chain reaction (PCR) were performed as confirmatory tests and to detect viremia, respectively. Virus genotype was identified by means of a Line Immuno Probe Assay in PCR positive samples. RESULTS: The overall prevalence of HCV infection was 0.195% (10/5105). Viremia was detected in 90% of the subjects. The prevalence of accepted donors (0.087%) was significantly lower (p = 0.017) than that of the rejected ones (0.421%). Among viremic subjects, 60 % were infected with genotype 2 and 40% with a subtype combination (a/b) of genotype 1. DISCUSSION: The prevalence of HCV infection in our population was significantly lower than the world mean prevalence estimated in 3 %. A higher prevalence of genotype 2 in asymptomatic individuals contrasts with previous studies with a selected population where genotype 1 prevailed.

Osteorregeneración: coagulite vs hidroxiapatita vs coagulite-hidroxiapatita en lesiones en maxilares de rata, con tomografía axial computarizada y microscopía electrónica de barrido / Osteoregeneration: coagulite vs hydroxyapatite vs coagulite hydroxyapatite in experimental maxillary injuries in rats, as determined by computarized tomography and electron microscopy

El propósito de este estudio fue evaluar la osteorregeneración de lesiones provocadas en maxilares de ratas Wistar, acelerando el proceso por medio de biomateriales simples y combinados. Se implantó coagulite o hidroxiapatita o coagulite-hidroxiapatita en seis ratas Wistar sanas, machos, de 24 semanas de edad y se siguieron los siguientes procedimientos según las normas de bioética en animales de experimentación: se anestesiaron con zolazepam y tiletamina (0.4 ml), abordaje quirúrgico con la técnica Semi-Newman; se les realizaron cuatro perforaciones en la maxila: dos del lado derecho y dos del izquierdo, con fresa redonda de carburo de 2 mm de di metro. Posteriormente se implantaron los biomateriales en cada una de las perforaciones. A (coagulite) maxilar derecho en la unión cigom tica-maxilar; B (hidroxiapatita), entre el primer y segundo molares derechos, C (coagulite-hidroxiapatita) en la unión cigom tica-maxilar izquierda y D (control) entre el primer y segundo molares izquierdos. Estas lesiones fueron analizadas por tomografía axial computarizada, microscopía electrónica de barrido y an lisis histológico. Para los valores densitométricos obtenidos a las 3, 6, 9 y 12 semanas de implantados los biomateriales, el an lisis de varianza (ANOVA) mostró diferencia estadística significativa con una p < 0.018. En el análisis de superficie (lleno de las cavidades), a 3, 6, 9, 12 y 15 semanas se utilizó la prueba de Kruskal-Wallis, ésta mostró una diferencia estadística significativa con una p < 0.03. El análisis histológico mostró que el coagulite tiene el mejor proceso de morfodiferenciación de las mmicroestructuras en la ingeniería tisular. Se concluye que la tomografía axial computarizada es una alternativa para evaluar osteorregeneración in vivo y que el coagulite es más eficaz en osteorregeneración que la hidroxiapatita y que el coagulite-hidroxiapatita de lesiones maxilares en ratas Wistar.