ABSTRACT In nine Caranx hippos specimens, Cd, Pb, Cr, and Cu concentration was determined in tissues (muscle and gonad) and parasites (nematodes and cestodes). The fish were caught from February to June 2019 in Las Barrancas, Alvarado Beach, Veracruz, Mexico. Heavy metals were quantified using atomic absorption spectrophotometer. The results of the average concentration of pollutants were, Cr = 0.18 ± 0.05 mg kg−1 dry weight (dw); Cu = 0.2 ± 0.1 mg kg−1 dw; Pb = 0.022 ± 0.01 mg kg−1 dw; Cd = <0.003 mg kg−1 dw. Among the tissues, Cu was the one with the highest concentration in nematodes vs. cestodes (2.2:1); vs. gonad (2.5:1); vs. muscle (2.7:1). Due to the concentration registered in Caranginema americanum nematodes could be identified as a bioindicator species for Cu pollutant. The values generally do not exceed the limits established in the Mexican National Standard (NOM-242-SSA1-2009) for Cd and Pb (0.5 mg kg−1). Records of heavy metals do not represent a health risk from consuming C. hippos.

ABSTRACT The objective of this work was to evaluate the acute toxicity of the commercial herbicides Karmex® (diuron: DCMU 3-(3,4-dichlorophenyl)-1,1-dimethylurea) and Herbipol® (glyphosate: N-(phosphonomethyl) glycine) on the megalopae of Callinectes sapidus and measure their relative abundance in the association of larval and postlarval species of crustaceans from the estuary of the Jamapa River, Veracruz. Collections were made overnight using white light traps. Likewise, dissolved oxygen, pH, temperature, total dissolved solids, and salinity were measured in situ. It was found that the association of larvae and postlarvae consisted of Macrobrachium acanthurus, M. olfersii, Potimirim mexicana, megalopae of C. sapidus and Armases ricordi, and zoeas of Brachyura. In total, 559 and 1057 C. sapidus megalopae were collected in November and March 2019, respectively. Dissolved oxygen was 6 and 7 mg L−1, pH was 7 and 8, the temperature was 26 and 27°C, total dissolved solids were 700 and 1500 ppm, and salinity was 0.70 and 16 in November and March, respectively. Using Probit analysis, a 96 h LC50 of diuron (Karmex®) was 7.69 ± 1.07 mg L−1 in March and 6.64 ± 0.93 mg L−1 in November. The LC50 for glyphosate (Herbipol®) was 247.83 ± 34.54 mg L−1 in March and 288.18 ± 38.66 3 mg L−1 in November. The blue crab C. sapidus is tolerant to a wide range of physicochemical factors; however, it is sensitive in the postlarval stages, like other species of crustaceans, to the herbicides diuron and glyphosate, for which the megalopae can be used in ecotoxicological studies.

ABSTRACT The Interdunary Lagoons System of the city of Veracruz (SLICV) is part of the natural ecosystems known as Ramsar sites, whose objective is focused on the conservation of ecological functions. This system comprises 18 lagoons in the Veracruz-Boca del Río metropolitan area, which are considered “infrequent” since they are fresh and shallow water bodies that provide different ecosystem services to the inhabitants of the area. The progressive loss of this services is due to various sources of anthropogenic pressure (for example, land-use change, lack of sanitation infrastructure, and increase of pollutants and dumped waste). The objective of this research was to characterize the waste dumping into the SLICV and its impact on the different ecosystem services of each lagoon. The 18 sampling sites were geographically delimited with a spatial analysis using Geographic Information Systems (GIS). Four types of waste were identified, being the urban solid the most predominant type. The regulation ecosystem service was the most impacted in almost every lagoon.

RESUMEN El Sistema de Lagunas Interdunarias de la Ciudad de Veracruz (SLICV) forma parte de los ecosistemas naturales conocidos como sitios Ramsar, cuyo objetivo se centra en la conservación de funciones ecológicas. Este sistema, ubicado en la zona conurbada Veracruz-Boca del Río, está constituido por 18 lagunas consideradas “poco frecuentes”, ya que son cuerpos de agua dulce, someros y proveen diferentes servicios ecosistémicos a los habitantes de la zona. La pérdida gradual de dichos servicios ecosistémicos se debe a diversas fuentes de presión antrópica (por ejemplo, el cambio en el uso del suelo, falta de infraestructura de saneamiento, incremento de contaminantes y residuos). La presente investigación tuvo como objetivo la caracterización de los residuos que se vierten en el SLICV y su impacto sobre los diferentes servicios ecosistémicos de cada laguna. Los 18 sitios de muestreo se delimitaron geográficamente con un análisis espacial mediante sistemas de información geográfica (SIG). Se identificaron cuatro tipos de residuos, de los cuales el sólido urbano fue el más predominante. El servicio ecosistémico de regulación fue el más impactado en casi todas las lagunas.

ABSTRACT Farmers have increased the production of food by using chemical substances such as diuron; however, these components affect the water quality and the species found in these ecosystems. Macrobrachium acanthurus and M. olfersii postlarvae present in the estuary of Río Jamapa, Veracruz were collected to measure the LC50 and LD50 using the herbicide Karmex (diuron: (3-(3,4-dichlorophenyl)-1,1-dimethylurea [DCMU]). The captures of the prawns were made with light traps. Acute toxicity bioassays were carried out at 96 h to determine the mean lethal concentration (LC50). In the experimental design, a geometric series was used considering the control and five concentrations of the herbicide (1.75, 3.5, 6.99, 14, and 28 mg/L). The data analysis was carried out with the Probit method. A maximum LC50 of 10.233 mg/L and LD50 of 8.221 mg/L of Karmex were obtained for M. acanthurus and a maximum LC50 of 9.242 mg/L and LD50 of 7.504 mg/L of Karmex were obtained for M. olfersii. The average lethal concentration was consistent with those of other crustaceans, such as Artemia salina and Daphnia. Based on the response in the bioassays, Macrobrachium acanthurus and M. olfersii postlarvae can be used in toxicology studies.

RESUMEN Los agricultores han aumentado la producción de alimentos mediante el uso de sustancias químicas como el Diurón; sin embargo, estos componentes afectan la calidad del agua y las especies que se encuentran en estos ecosistemas. Se recolectaron postlarvas de Macrobrachium acanthurus y M. olfersii presentes en el estuario del Río Jamapa, Veracruz para medir la CL50 y DL50 utilizando el herbicida Karmex (diuron: DCMU (3-(3,4-diclorofenil)-1,1-dimetilurea). Se realizaron las capturas de los langostinos con trampas de luz. Los bioensayos de toxicidad aguda se midieron a las 96 h para determinar la concentración letal media (CL50). En el diseño experimental se utilizó una serie geométrica considerando el testigo y cinco concentraciones del herbicida (1.75, 3.5, 6.99, 14 y 28 mg/L). El análisis de datos se realizó con el método Probit. Se obtuvo una CL50 máxima de 10.233 mg/L y una DL50 de 8.221 mg/L de Karmex para M. acanthurus y una CL50 máxima de 9.242 mg/L y DL50 de 7.504 mg/L de Karmex para M. olfersii. La concentración letal promedio fue consistente con la de otros crustáceos, como Artemia salina y Daphnia. Con base en la respuesta en los bioensayos, se pueden utilizar postlarvas de Macrobrachium acanthurus y M. olfersii en estudios de toxicología.

Abstract Every year millions of cubic meters of wastewater are discharged into water bodies, which are treated in an inadequate way, these procedures being inefficient to achieve what is required by law or for use within industrial processes. In these cases, and due to the scarcity of water, the use of advanced oxidation processes is being used as an alternative treatment, which are based on physicochemical processes capable of producing profound changes in the chemical structure of pollutants, involving the generation and the use of transitory species with great oxidizing power, mainly the hydroxyl radical, which can be generated by photochemical means or by other forms of energy, and is highly effective in the oxidation of organic matter. This review aims to perform an analysis of the influence of treatments on the decontamination process.

Resumen Cada año se vierten millones de metros cúbicos de aguas residuales a los cuerpos de agua, las cuales son tratadas de forma inadecuada, siendo estos procedimientos ineficientes para alcanzar lo requerido por la ley o para uso dentro de los procesos industriales. En estos casos, y debido a la escasez del hídrico, se está recurriendo al uso de los procesos de oxidación avanzada como tratamiento alternativo. Estos procesos se basan en procesos fisicoquímicos capaces de producir cambios profundos en la estructura química de los contaminantes, involucrando la generación y uso de especies transitorias de gran poder oxidante, principalmente el radical hidroxilo, el cual puede ser generado por medios fotoquímicos o por otras formas de energía y posee alta efectividad para la oxidación de materia orgánica. Esta revisión tiene como objetivo realizar un análisis de la influencia de los tratamientos en el proceso de descontaminación.

ABSTRACT Background: The southern zone of the estuary of the Jamapa River, Veracruz, is a place of transition between the river and the marine environment to which sediments, compounds, and species of crustaceans are transported to the neritic zone where is the Parque Nacional Sistema Arrecifal Veracruzano. Objective: The responses of exposure of Potimirim mexicana postlarvae to diuron, glyphosate, and paraquat, as well as the relative abundance, diversity of the association of crustaceans, and values of temperature, salinity, oxygen, pH, and dissolved solids in the estuary were evaluated. Methods: Sampling was carried out with white light traps in November and March. Living Potimirim mexicana postlarvae were obtained from the samples to carry out the bioassays; the remaining individuals of the association were fixed in 70% alcohol for identification and quantification. The environmental factors were measured using a multiparameter Hanna HI 9828. Results: Dissolved oxygen was of 6-7 mgL-1, pH of 8-9, temperature of 26-27° C, total dissolved solids of 700-1,500 ppm and salinity of 0.70-16 ups. Environmental conditions permit the presence of Potimirim mexicana postlarvae. Six taxa were found: postlarvae of Macrobrachium acanthurus, M. olfersii and Potimirim mexicana, megalopae of Callinectes sapidus and Armases ricordi, and zoeae of Brachyura. Diversity ranged from 1.55 to 1.77 bits*individual-1, indicating an intermediate stability of the estuary. A total of 12,827 postlarvae of P. mexicana were obtained. The LC50 values of diuron, paraquat, and glyphosate were 5.94, 1.51, and 221.05 mgL-1, respectively. Conclusions: The values found here are consistent with those obtained by other authors for different species of crustaceans. Due to the important ecological in the food web of P. mexicana, its postlarvae can be used as sensitive test organisms in ecotoxicological studies.

RESUMEN Antecedentes: La zona sur del estuario del río Jamapa, Veracruz, es un lugar de transición entre el río y el medio marino al que se transportan sedimentos, compuestos y especies de crustáceos hasta la zona nerítica donde se encuentra el Parque Nacional Sistema Arrecifal Veracruzano. Objetivo: Se evaluaron las respuestas de exposición de las postlarvas de Potimirim mexicana a diurón, glifosato y paraquat, así como la abundancia relativa, diversidad de asociación de crustáceos y valores de temperatura, salinidad, oxígeno, pH y sólidos disueltos en el estuario. Métodos: El muestreo se realizó con trampas de luz blanca en noviembre y marzo. De las muestras se obtuvieron postlarvas vivas de Potimirim mexicana para realizar los bioensayos; los restantes individuos de la asociación se fijaron en alcohol al 70% para su identificación y cuantificación. Los factores ambientales se midieron utilizando un multiparamétrico Hanna HI 9828. Resultados: El oxígeno disuelto fue de 6-7 mgL-1, pH de 8-9, temperatura de 26-27 ° C, sólidos disueltos totales de 700-1,500 ppm y salinidad de 0,70-16 ups. Las condiciones ambientales permiten la presencia de postlarvas de Potimirim mexicana. Se encontraron seis taxones: postlarvas de Macrobrachium acanthurus, M. olfersii y Potimirim mexicana, megalopas de Callinectes sapidus y Armases ricordi y zoeas de Brachyura. La diversidad osciló entre 1,55 y 1,77 bits*individuo-1, lo que indica una estabilidad intermedia del estuario. Se obtuvieron un total de 12,827 postlarvas de P. mexicana. Los valores de LC50 de diurón, paraquat y glifosato fueron 5.94, 1.51 y 221.05 mgL-1, respectivamente. Conclusiones: Los valores aquí encontrados son consistentes con los obtenidos por otros autores para diferentes especies de crustáceos. Debido a la importancia ecológica en la trama trófica de P. mexicana, sus postlarvas pueden usarse como organismos de prueba sensibles en estudios ecotoxicológicos.

RESUMEN Se efectuó un examen helmintológico a 14 especímenes de Eucinostomus melanopterus (mojarra bandera) y 19 Eugerres plumieri (mojarra rayada), de los cuales se recolectaron un total de 461 helmintos. Se identificaron 12 taxones (cinco a nivel de especie, cinco a género y dos a familia) como sigue: cuatro monogéneos, cinco digéneos (cuatro adultos, una metacercaria), un céstodo (plerocercoide) y dos nemátodos (larvas). La prevalencia más alta fue para Neodiplectanum mexicanum (29 %) en E. melanopterus y Aristocleidus hastatus (37 %) en E. plumieri. Ambos hospederos comparten el 50 % de los taxones de parásitos. Ninguno de los helmintos representa un riesgo zoonótico.

ABSTRACT A helminthological examination was carried out on 14 specimens of Eucinostomus melanopterus (flagfin mojarra) and 19 Eugerres plumieri (striped mojarra), of which a total of 461 helminths were collected. As a result, and 12 taxa were registered (five species, five genus and tow family), as follows: four monogeneans, five digeneans (four adults, one metacercaria), one cestode (larva) and tow nematodes (larvae). The highest prevalence was for Neodiplectanum mexicanum (29 %) infecting E. melanopterus and Aristocleidus hastatus (37 %) infecting E. plumieri. Both hosts shared 50 % of recorded species, and none of the identified helminthes represents a zoonotic risk.

Abstract: Oreochromis spp., is an important resource and aquaculture crop in different species have been detected P de monogeneans parasites, but we ignore the presence of parasites in specimens of sale. They were studied to helminthology to 9 fish on day one and 9 on the 15th day of a selling point of live tilapia. We recorded 5 species of monogeneans four species of gill parasites: Scutogyrus longicornis, Cichlidogyrus dossoni, C. sclerosus, C. tilapiae and a kind of intestinal monogenean Enterogyrus malmbergi. No species of other groups of parasites were recovered. The prevalence and average intensity higher was for C. sclerosus in both groups and no host zoonotic risk.

Resumen: Oreochromis spp., es un importante recurso acuícola y en los cultivo se han detectado diferentes especies Pde monogéneos parásitos, pero desconocemos la presencia de parásitos en especímenes de venta. Se estudiaron para helmintología a 9 peces en el día uno y 9 en el día 15 de un punto de venta de tilapia viva. Registramos 5 especies de monogéneos, cuatro especies parásitos de branquias: Scutogyrus longicornis, Cichlidogyrus dossoni, C. sclerosus, C. tilapiae y una especie de monogéneo intestinal Enterogyrus malmbergi. No se recuperaron especies de otros grupos de parásitos. La mayor prevalencia e intensidad promedio fue para C. sclerosus en ambos grupos de hospederos y no hay riesgo zoonótico.

Background: Patients with Silver-Russell syndrome suffer from severe intrauterine and postnatal growth retardation, relative macrocephaly and body asymmetry, among other characteristics. It is caused by several genetic and epigenetic mechanisms in 11p15.5 in 40% of the cases and maternal uniparental disomy of chromosome 7 in 10%. Methods: Twenty patients with a diagnosis of Silver-Russell syndrome who were seen at the HIMFG from 1998 to 2012, were evaluated according to international clinical criteria confirming the diagnosis in nine of the subjects. Results: All patients showed intrauterine and postnatal growth retardation and short stature, both considered as major criteria of Silver-Russell syndrome. Relative macrocephaly was present in 78% of the patients and asymmetry in 33%. Other characteristics such as renal tubular acidosis were present > 50% of the cases. Conclusions: The clinical diagnosis of Silver-Russell syndrome is complex. Short stature is the main reason for seeking medical attention and is helpful in the identification of a differential diagnosis. This situation underlines the importance of growth and development evaluation of all patients and particularly in those with short stature to identify those cases that may require molecular studies, with implications in management, prognosis and genetic counseling.

Introducción: El síndrome de Silver-Russell presenta restricción del crecimiento intrauterino y posnatal, macrocefalia relativa y asimetría, entre otras características. Es causado por mecanismos genéticos y epigenéticos en el cromosoma 11p15.5 en el 40% de los casos y por disomía uniparental materna del cromosoma 7 en el 10%. Métodos: Se identificaron los pacientes con diagnóstico de síndrome de Silver-Russell del Hospital Infantil de México Federico Gómez atendidos de 1998 a 2012; se reevaluaron 20 pacientes según los criterios clínicos internacionales, y se confirmó el diagnóstico en nueve sujetos. Resultados: Todos los pacientes presentaron restricción del crecimiento intrauterino y talla baja, ambos criterios diagnósticos mayores. La macrocefalia relativa estuvo presente en el 78% y la asimetría corporal solo en el 33%. Otras características, como la acidosis tubular renal, estuvieron presentes en más del 50%. Conclusiones: El diagnóstico del síndrome de Silver-Russell es complejo, por lo que contar con criterios clínicos adecuados es fundamental. Dado que la talla baja es la principal solicitud de atención médica en este síndrome, es relevante establecer diagnósticos diferenciales y valorar el crecimiento y desarrollo de todos los pacientes para identificar a aquellos en quienes la talla baja forma parte de una entidad sindrómica y que serían candidatos para realizar estudios moleculares. Este abordaje tendrá implicaciones para su manejo, pronóstico y asesoramiento genético.

LA DIABETES MELLITUS (DM) comprende un grupo heterogéneo de desordenes hiperglucémicos clasificados en subgrupos de acuerdo a su fisiopatología y etiología, entre los cuales se destacan la Diabetes Mellitus tipo1 (DM1) y la diabetes mellitus tipo 2 (DM2). La DM1 es de aparición temprana y una absoluta escasez de insulina hace que los pacientes sean insulino dependientes desde el inicio de los síntomas y la (DM2), de inicio en la edad adulta y no todos los pacientes que la sufren son insulino dependientes. La DM1 se clasifica como DM1A si es el efecto de una respuesta autoinmune por parte de las células del páncreas y DM1B si la causa es desconocida (idiopática). Los estudios sobre la etiología de DM1 han demostrado que ambos subtipos tienen un fuerte componente genético, pero el patrón de herencia es complejo, ya que su patogénesis puede ser el resultado de la interacción de variantes en múltiples genes con factores medioambientales. Los estudios genéticos sobre DM1 han permitido identificar loci de suceptibilidad que se denominan IDDM, así para DM1A se encontró el primer locus (IDDM1) en la región HLA-DR/DQ, situada en 6p21, que modula el efecto de otros genes implicados en la enfermedad, el segundo (IDDM2) se localiza en 11p15 donde se encuentra el gen de la Insulina. Es decir, DM1 presenta gran heterogeneidad genética, de tal manera, que se han identificado más de 18 loci implicados en susceptibilidad a ella, entre ellos 3 en el cromosoma 2 (IDDM 7,12 y 13) y uno en el cromosoma 14 (IDDM11), este último asociado a DM1B. El objetivo de este estudio consistió en la búsqueda de loci en los cromosomas 2 y 11 involucrados en la susceptibilidad a DM, en 3 familias antioqueñas, para lo cual se realizó análisis de ligamiento paramétrico a 23 marcadores microsatélites en el cromosoma 2 y a 18 en el cromosoma 11. A las familias, codificadas como DM1(11afectados), familia 1 (2 afectados) y familia10 (3 afectados), se les realizó simulación para determinar el poder para hacer análisis de ligamiento y los resultados mostraron que presentaban suficiente poder para realizarlo, puesto que en DM1 la razón de disparidad máxima (Lod score o Z máximo) fue de 3.57, sin recombinación (θ=0), el cual es superior a 3, el valor aceptado para determinar ligamiento, y al tomar las tres familias en conjunto se obtuvo un Z máximo de 5.76. Con el análisis de ligamiento para el cromosoma 11, se halló que solo en la familia 10 se presentaba un valor positivo de Z; 1.18 al marcador D11S925 con ?=0, muy superior al de la simulación de esta familia (0.75), con respecto al cromosoma 2, se obtuvieron valores de Z positivos al marcador D2S319 en DM1 y familia 10, 2.08 y 0.88 respectivamente, con θ=0. Al tomar las tres familias como un todo y calcular Z para los marcadores D11S925 y D2S319, se obtuvo un valor de 2.5, con θ=0, lo cual está corroborando que en las familias analizadas están involucrados 2 loci, situados en las regiones de los cromosomas 11 y 2 señaladas por dichos marcadores. Si se tiene en cuenta que el marcador D11S925 está situado en la región 11q23-3 y el D2S319 en la 2qter, se puede decir, que con este trabajo se han identificado 2 loci nuevos de susceptibilidad a DM1 en la población antioqueña, ya que estas regiones no concuerdan con las reportadas hasta el presente; además, como se hizo análisis de ligamiento a IDDM1, con resultados negativos (datos no mostrados), la DM1 estudiada podría clasificarse como DM1B.

DIABETES MELLITUS (DM) comprises e heterogeneous group of hypoglycemic disorders, that are grouped according to their physiopathology and etiology; the most notorious ones are type 1 DM (DM1) and type 2 DM (DM2); DM1 is characterized by early onset and absolute lack of insulin; therefore, patients suffering from it depend on insulin since the beginning of their symptoms; in contrast, DM2 manifests during adult life and not all patients depend on insulin. DM1 is classified as DM1A when it results from an autoimmune response of pancreatic b cells, and DM1B if it is of unknown origin (idiopathic). Studies on the etiology of DM1 have revealed that both types have a strong genetic component but their inheritance pattern is complex since its pathogenesis may result from the interaction with environmental factors of variants in multiple genes. By means of genetic studies on DM1, susceptibility loci known as IDDM have been identified, namely: for DM1A the first locus (IDDM1) was found in the HLA-DR/QD region, located in 6p21, that modulates the effect of other genes involved in the disease; the second one (IDDM2) is located in 11p15, the site of the insulin gene. That means, DM1 exhibits wide genetic heterogeneity so that more than 18 loci involved in susceptibility to this disease have been identified, among them, 3 on chromosome 2 (IDDM 7, 12, and 13), and 1on chromosome 14 (IDDM11), the latter being associated to DM1B. The aim of this study was the search for loci on chromosomes 2 and 11 involved in the susceptibility to DM, in three families from Antioquia, Colombia; for that purpose, parametric linkage analysis was performed to 23 microsatellite markers on chromosome 2, and to 18 on chromosome 11. In order to determine the power for making linkage analysis, simulation was carried out on the families, coded as DM1 (11 affected members), family 1 (2 affected members), and family 10 (3 affected members); results demonstrated power enough for that purpose since in DM1 the maximum odds ratio (Lod score or Z maximum) was 3.57 without recombination (=0=0), above 3, the accepted value for determining linkage; when the three families were taken together, a maximum Z of 5.76 was obtained. With the linkage analysis for chromosome 11, it was found that only in family 10 there was a positive Z value, 1.18 to marker D11S925 with =0=0, above the simulation value for this family (0.75); as regards chromosome 2, positive Z values were obtained to marker D2S319 in DM1 and family 10: 2.08 and 0.88, respectively, with =0=0. When the three families were taken as a whole and Z values were calculated for markers D11S925 and D2S319, a value of 2.5 was obtained, with =0=0, which confirms that in the analysed families 2 loci are involved, located in the regions of chromosomes 11 and 2 signaled by such markers. If it is taken into account that the D1S925 marker is located in the region 11q23-3, and the D2S319 marker, in the region 2qter, it may be said that in this work two new loci of susceptibility to DM1 have been identified in three families from Antioquia, Colombia, since these regions do not agree with those so far reported; besides, since results were negative in linkage analysis to IDDM1(data not shown), the studied cases of DM1 could be classified as DM1B.

The possible relationship between erythrocyte antigens and the presence of malaria infection by P. vivax and P. falciparurn was sought in four different ethnic groups of two departments of Colombia. Malaria infection by P. falciparum was found in 91.4% of malaria infected blacks. No significant differences were found between the presence of malaria infection and ABO antigens. In the other blood groups, it was observed that groups MNSs conferred black people a greater Rr for malaria by both species of Plasmodium and that Duffy-negative blacks and indians appeared to be resistant to P. vivax infection. A predominance of P. vivax infection was observed in Katio indians while P.falciparum was predominant in Kuna indians; the reason for this finding still needs to be explored.

Con el presente estudio se evalúa la relación existente entre la infección por P. vivax y P. falciparum y los antígenos eritrocitos de cuatro diferentes grupos étnicos en Colombia. P. falciparum se encontró causando malaria en el 91.4% de los individuos de raza negra que tuvieron malaria. No hubo diferenciais significativas entre la infección malaria y los antígenos ABO. La presencia de grupos del sistema MNSs en persona de raza negra confiere un mayor riesgo relativo por la infección para las dos especies de Plasmodium, igualmente hay mayor riesgo cuando se pertenece a la raza negra o indígena y el grupo Duffy es negativo. La infección por P. vivax predomina en los indios Katios pero en los Kunas prevalece P. falciparum.

Foram estudados os antigenos HLA e a relação destes com a infecção malárica em 4 diferentes grupos étnicos da Colômbia (América do Sul); dois grupos de índios (Kunas e Katios), um grupo de negros e um grupo que apresentava ancestrais mistos. Foram estudadas 965 pessoas, das quais 415 com malária e 550 como controles. A freqüência dos antígenos HLA-A, B e C foram determinados nos quatro grupos estudados. A associação de cada antígeno HLA com a infecção por P. vivax e P. falciparum foi avaliada. Os antígenos HLA 6-9 encontrados no grupo de ancestrais mistos, de um modo geral não foram observados nos grupos de negros e índios (Kunas e Katios). Nos grupos étnicos mencionados, os antigenos B5, B13, B15, Cw2 e Cw4 apresentaram uma associação limítrofe com a infecção por malária. Entretanto, no grupo étnico de ancestrais mistos foi observada uma associação estatisticamente significativa com a infecção malárica, sendo que a presença de A9, Aw19, B17, B35 e Z98 (B21-B45: determinantes de reação cruzada) mostrou poucas diferenças quando as infecções por P. vivax e P. falciparum foram consideradas individualmente. Esse achado pode representar, de um modo geral, uma falta de resistência a malária no grupo portador de antigenos de origem caucasiana, os quais tem tido um contacto direto e permanente com a malária somente nos últimos 65 anos. Em contraste, os índios (Kunas e Katios) e os negros tem vivido durante séculos em áreas endêmicas para malária, é possível que um sistema de seleção natural tenha sido desenvolvido permitindo que somente aqueles indivíduos capazes de iniciar uma resposta imune à malária sobrevivam.

HLA antigens and their relationship with malaria infection were studied in four different ethnic groups in Colombia (South America): two groups of indians (Kunas and Katios), one of negroes and a group of mixed ancestry. A total of 965 persons were studied, 415 with malaria and 550 as controls. HLA-A,B, and C antigen frequencies in the four groups are reported. The association of each HLA antigen with malaria infection due to P. vivax and to P. falciparum was evaluated. Negroes, Kunas and Katios indians variously lack from 6 to 9 of the HLA antigens found in the mixed group. In the designated ethnic groups, antigens B5, B13, B15, Cw2 and Cw4 showed borderline association with malaria infection. However, in the mixed ethnic group, statistically significant associations were found with malaria infection and the presence of A9, Aw19, B17, B35, and Z98 (a B21-B45: crossreacting determinant) with few differences when P. vivax infection and P. falciparum infection were considered individually. This finding may represent a lack of general resistance to malaria in the group that harbors antigens of Caucasian origin. These individuals have been in direct and permanent contact with malaria only in the past 65 years. In contrast, indians, both Kunas and Katios, and Negroes have lived for centuries in malaria endemic areas, and it is possible that a natural selection system has developed through which only those individuals able to initiate an acute immune response to malaria have survived.