Alteraciones inmunes humorales causadas por plomo: estudios en un modelo de sapo adulto

There is evidence that environmental metal levels affect the immune function. In the particular case of the impact of heavy metals, information available suggests that the immune system is a target for low-dose Pb exposure. Among vertebrates it was shown that amphibians are capable of forming antibodies against a variety of antigens, causing several responses such as anaphylactic response and rejecting grafts. In this study, the production of antibodies was assessed against sheep red blood cells (SRBC) in the anuran Bufo arenarum after six weekly injections of sublethal doses of lead (50 mg.kg-1, as lead acetate). Natural antibodies (natural heteroagglutinins) were also quantified against SRBC. Both assessments were carried out employing an ELISA method developed to this end, measuring absorbance (A). For natural anti-SRBC antibodies in both control (C) and Pb treated (T) toads, there was a non significant tendency to increase the initial absorbances (C initial: 0.69+0.39 A; T initial: 0.54+0.30 A), relative to those registered at the end of the experiments (C final: 0.89+0.49 A; T final: 0.76+0.31A); the T/C ratios also did not show changes. The only significant difference was found between initial and final samples from lead-treated toads (p<0.014). The immune anti- SRBC antibody levels of toads immunized with SRBC showed a significant lower increase (p<0.05) in lead-treated animals (T final: 0.66+0.36 A), as compared to control toads (C final: 0.91+0.50 A) at the end of the experiment. It was thus concluded that the changes due to the assayed doses of Pb in the levels of antibodies cannot be explained on the basis of only one single action mechanism of the metal, but as the result of a conjunction of effects over different immunocompetent cell subpopulations. These different responses suggest that factors affecting animals exposed to a foreign stimulus are different from those influencing the response of wild animals.Existe evidencia de que los niveles de metal ambientales afectan la función inmune. En el caso particular del impacto de metales pesados, la información disponible sugiere que el sistema inmune es un blanco para la exposición a bajas dosis de Pb. Entre los vertebrados, se ha mostrado que los anfibios son capaces de formar anticuerpos contra una variedad de antígenos, que causan diversas respuestas, tales como respuesta anafiláctica y rechazo de injertos. En este estudio, la producción de anticuerpos fue evaluada contra eritrocitos de oveja (EO) en el anuro Bufo arenarum, luego de seis inyecciones semanales de dosis subletales de plomo (50 mg.kg-1, como acetato de Pb). Los anticuerpos naturales (heteroaglutininas naturales) fueron también cuantificados contra EO. Ambas evaluaciones fueron llevadas a cabo empleando un método de ELISA desarrollado a este fin, midiendo la absorbancia (A). Para los anticuerpos anti-EO naturales, tanto en sapos controles (C) como en sapos tratados con Pb (T), hubo una tendencia significativa a incrementar las absorbancias iniciales (C inicial: 0,69+0,39 A; T inicial: 0,54+0,30 A); la relación T/C tampoco mostró cambios. La única diferencia significativa se encontró entre las muestras inicial y final de los sapos tratados con plomo (p&lt;0,014). Los niveles de anticuerpos anti-EO inmune de sapos inmunizados con EO mostraron un bajo incremento significativo (p&lt;0,05) en los animales tratados con plomo (T final: 0,66+0,36 A), al compararse con sapos control (C final: 0,91+0,50 A) al final del experimento. De este modo, se concluye que los cambios debidos a las dosis analizadas de Pb en los niveles de anticuerpos no pueden explicarse sólo sobre la base de un único mecanismo de acción del metal, sino como resultado de una conjunción de efectos sobre diferentes subpoblaciones de células inmunocompetentes. Estas diferentes respuestas sugieren que los factores que afectan los animales expuestos a un estímulo externo son diferentes de aquellos que influyen la respuesta en los animales silvestres.Facultad de Ciencias ExactasComisión de Investigaciones Científicas de la provincia de Buenos Aire

Effect of lead acetate on the in vitro engulfment and killing capability of toad (<i>Bufo arenarum</i>) neutrophils

Lead is an element of risk for the environment and human health and has harmful effects that may exceed those of other inorganic toxicants. The immune system is one ofthe targets of lead. Its immunomodulatory actions depend on the level of exposure, and it has been demonstrated that environmental amounts of the metal alter immune function. Very little information is available regarding the effect of the metal on different aspects of the immune system of lower vertebrates, in particular of amphibians. The aim of this study was to investigate the effect of sublethal lead (as acetate) on the function of polymorphonuclear cells of Bufo arenarum. The results revealed that phagocytic and lytic functions ofthe adherent blood cells collected from sublethal lead-injected toads and incubated with suspensions of Candida pseudotropicalis were affected negatively. The decrease of the phagocytic activity was correlated with increased blood lead levels (P-0.0001). Additional information referred to the total and differential leukocyte counts was presented; the only difference found was in the number of blast-like cells that resulted augmented in the samples of lead-injected toads. It was concluded that the evaluation ofthese parameters might be a reliable tool for the biological monitoring of the immune status of amphibians.Facultad de Ciencias ExactasComisión de Investigaciones Científicas de la provincia de Buenos Aire

Serum Protein Profile and Blood Cell Counts in Adult Toads Bufo Arenarum (Amphibia: Anura: Bufonidae) : Effects of Sublethal Lead Acetate

Lead is a multiple-source pollutant, well known for its toxicity, of great risk both for the environment and human health. The main target organs of lead are the hematopoietic, nervous, and renal systems; there are also reports in support of its impairment effects on the reproductive and immune systems. It is well known that most of the metal is accumulated in the blood cells and that many of the deleterious effects are related to its circulating concentrations. These adverse effects have been described not only in humans but also in a number of other vertebrates such as fish and birds. The purpose of the present work was to evaluate the effects of weekly administration of sublethal Pb (as acetate, 50 mg ċ kg−1) during 6 weeks on the profile of the serum proteins and blood cell counts of the adult South American toad, Bufo arenarum (Anura: Bufonidae). The electrophoretic patterns of serum proteins pointed out the presence of four fractions; the metal provoked a significant decrease in both total proteins and albumin fraction; among the globulin fractions, the G3 resulted augmented. These findings may be related to the impact of lead on the toads’ hepatic cells and immune system. The number of total red blood cells (RBC) showed a tendency to decrease after the injections of the metal, whereas the number of white blood cells (WBC) increased significantly; the differential leukocyte counts showed a statistically significant increase in the absolute number and in the relative percentage of blast-like cells. The decrease in RBC was attributed to the negative impact of the metals on the hemoglobin synthesis. The increasing of the WBC counts may be interpreted as a consequence of the induction of proliferation of pluripotential hematopoietic cells.Facultad de Ciencias Exacta

Bibliometric analysis of communications presented at Congreso Nacional Bioquímico, between 1997 and 2005

Un congreso es una reunión científica multitudinaria, con cientos o miles de participantes, dirigida a profesionales de una disciplina o campo del conocimiento, para difundir, discutir e intercambiar información sobre avances recientes. El programa incluye tres subprogramas: actualización, educación y comunicaciones libres. La Bibliometría se ocupa de analizar estadísticamente la información registrada en publicaciones científicas, habiéndose propuesto tres tipos de indicadores bibliométricos para congresos: cuantitativos, cualitativos y de evidencia científica. El propósito del presente trabajo ha sido analizar, según indicadores cuantitativos, las comunicaciones del Congreso Nacional Bioquímico de la Confederación Unificada Bioquímica de la República Argentina (CUBRA). Se analizaron las comunicaciones presentadas en los congresos de Tucumán 1997, Huerta Grande 1999, Bariloche 2001, Posadas 2003 y San Juan 2005. El total de comunicaciones fue 388, todas en formato poster. La mediana fue de 4 autores por comunicación. Las principales áreas temáticas fueron Química Clínica, (incluyendo Endocrinología y Medio Interno, 45,4%) y Microbiología (incluyendo Bacteriología, Parasitología, Micología y Virología, 21,1%). El 34,3% provenía de universidades, 27,1% de hospitales y 23,7% por colaboración entre 2 instituciones, siendo el principal aporte de: Universidad de Buenos Aires (n=35, 9,0%), Fundación Bioquímica Argentina (n=30, 7,7%) y Universidad Nacional de Tucumán (n=26, 6,7%).A congress is a multitudinous scientific meeting, with hundreds or thousands of participantes, wich is addressed to professionals of a discipline or knowledge field, to disseminate, discuss and exchange information about recent advances. It includes three subprograms: updating, education and free communications. Bibliometrics sta- tistically analyzes the information recorded in scientific publications. Three bibliometric indica- tors have been proposed for congressess: quantitative, qualitative and scientific evidence ones. The aim of this work has been to analyze, through quantitative bibliometric indicators, the communications submitted at the Congreso Nacional Bioquímico of Confederación Unificada Bioquímica de la República Argentina (CUBRA). The analysis was done on the communications submitted at congresses held in Tucumán 1997, Huerta Grande 1999, Bariloche 2001, Posadas 2003 and San Juan 2005. A total of388 communications were presented, all of them as posters. Median was 4 authors per communication. The main topical areas were Clinical Chemistry (including Endocrinology and Acid Base/Blood Gases, 45.4%) and Microbiology (including Bacteriology Parasitology Mycology and Virology 21.1%). A total of 34.3% came from universities, 27.1% of hospitals and 23.7% in collaboration from 2 institutions, being the main participation of Universidad de Buenos Aires (n=35, 9.0%), Fundación Bioquímica Argentina (n=30, 7.7%) and Universidad Nacional de Tucumán (n=26, 6.7%).Facultad de Ciencias ExactasFacultad de Humanidades y Ciencias de la Educació

Bibliometric analysis of communications presented at Congreso Nacional Bioquímico, between 1997 and 2005

Un congreso es una reunión científica multitudinaria, con cientos o miles de participantes, dirigida a profesionales de una disciplina o campo del conocimiento, para difundir, discutir e intercambiar información sobre avances recientes. El programa incluye tres subprogramas: actualización, educación y comunicaciones libres. La Bibliometría se ocupa de analizar estadísticamente la información registrada en publicaciones científicas, habiéndose propuesto tres tipos de indicadores bibliométricos para congresos: cuantitativos, cualitativos y de evidencia científica. El propósito del presente trabajo ha sido analizar, según indicadores cuantitativos, las comunicaciones del Congreso Nacional Bioquímico de la Confederación Unificada Bioquímica de la República Argentina (CUBRA). Se analizaron las comunicaciones presentadas en los congresos de Tucumán 1997, Huerta Grande 1999, Bariloche 2001, Posadas 2003 y San Juan 2005. El total de comunicaciones fue 388, todas en formato poster. La mediana fue de 4 autores por comunicación. Las principales áreas temáticas fueron Química Clínica, (incluyendo Endocrinología y Medio Interno, 45,4%) y Microbiología (incluyendo Bacteriología, Parasitología, Micología y Virología, 21,1%). El 34,3% provenía de universidades, 27,1% de hospitales y 23,7% por colaboración entre 2 instituciones, siendo el principal aporte de: Universidad de Buenos Aires (n=35, 9,0%), Fundación Bioquímica Argentina (n=30, 7,7%) y Universidad Nacional de Tucumán (n=26, 6,7%).A congress is a multitudinous scientific meeting, with hundreds or thousands of participantes, wich is addressed to professionals of a discipline or knowledge field, to disseminate, discuss and exchange information about recent advances. It includes three subprograms: updating, education and free communications. Bibliometrics sta- tistically analyzes the information recorded in scientific publications. Three bibliometric indica- tors have been proposed for congressess: quantitative, qualitative and scientific evidence ones. The aim of this work has been to analyze, through quantitative bibliometric indicators, the communications submitted at the Congreso Nacional Bioquímico of Confederación Unificada Bioquímica de la República Argentina (CUBRA). The analysis was done on the communications submitted at congresses held in Tucumán 1997, Huerta Grande 1999, Bariloche 2001, Posadas 2003 and San Juan 2005. A total of388 communications were presented, all of them as posters. Median was 4 authors per communication. The main topical areas were Clinical Chemistry (including Endocrinology and Acid Base/Blood Gases, 45.4%) and Microbiology (including Bacteriology Parasitology Mycology and Virology 21.1%). A total of 34.3% came from universities, 27.1% of hospitals and 23.7% in collaboration from 2 institutions, being the main participation of Universidad de Buenos Aires (n=35, 9.0%), Fundación Bioquímica Argentina (n=30, 7.7%) and Universidad Nacional de Tucumán (n=26, 6.7%).Facultad de Ciencias ExactasFacultad de Humanidades y Ciencias de la Educació

Alteraciones inmunes humorales causadas por plomo: estudios en un modelo de sapo adulto

There is evidence that environmental metal levels affect the immune function. In the particular case of the impact of heavy metals, information available suggests that the immune system is a target for low-dose Pb exposure. Among vertebrates it was shown that amphibians are capable of forming antibodies against a variety of antigens, causing several responses such as anaphylactic response and rejecting grafts. In this study, the production of antibodies was assessed against sheep red blood cells (SRBC) in the anuran Bufo arenarum after six weekly injections of sublethal doses of lead (50 mg.kg-1, as lead acetate). Natural antibodies (natural heteroagglutinins) were also quantified against SRBC. Both assessments were carried out employing an ELISA method developed to this end, measuring absorbance (A). For natural anti-SRBC antibodies in both control (C) and Pb treated (T) toads, there was a non significant tendency to increase the initial absorbances (C initial: 0.69+0.39 A; T initial: 0.54+0.30 A), relative to those registered at the end of the experiments (C final: 0.89+0.49 A; T final: 0.76+0.31A); the T/C ratios also did not show changes. The only significant difference was found between initial and final samples from lead-treated toads (p<0.014). The immune anti- SRBC antibody levels of toads immunized with SRBC showed a significant lower increase (p<0.05) in lead-treated animals (T final: 0.66+0.36 A), as compared to control toads (C final: 0.91+0.50 A) at the end of the experiment. It was thus concluded that the changes due to the assayed doses of Pb in the levels of antibodies cannot be explained on the basis of only one single action mechanism of the metal, but as the result of a conjunction of effects over different immunocompetent cell subpopulations. These different responses suggest that factors affecting animals exposed to a foreign stimulus are different from those influencing the response of wild animals.Existe evidencia de que los niveles de metal ambientales afectan la función inmune. En el caso particular del impacto de metales pesados, la información disponible sugiere que el sistema inmune es un blanco para la exposición a bajas dosis de Pb. Entre los vertebrados, se ha mostrado que los anfibios son capaces de formar anticuerpos contra una variedad de antígenos, que causan diversas respuestas, tales como respuesta anafiláctica y rechazo de injertos. En este estudio, la producción de anticuerpos fue evaluada contra eritrocitos de oveja (EO) en el anuro Bufo arenarum, luego de seis inyecciones semanales de dosis subletales de plomo (50 mg.kg-1, como acetato de Pb). Los anticuerpos naturales (heteroaglutininas naturales) fueron también cuantificados contra EO. Ambas evaluaciones fueron llevadas a cabo empleando un método de ELISA desarrollado a este fin, midiendo la absorbancia (A). Para los anticuerpos anti-EO naturales, tanto en sapos controles (C) como en sapos tratados con Pb (T), hubo una tendencia significativa a incrementar las absorbancias iniciales (C inicial: 0,69+0,39 A; T inicial: 0,54+0,30 A); la relación T/C tampoco mostró cambios. La única diferencia significativa se encontró entre las muestras inicial y final de los sapos tratados con plomo (p&lt;0,014). Los niveles de anticuerpos anti-EO inmune de sapos inmunizados con EO mostraron un bajo incremento significativo (p&lt;0,05) en los animales tratados con plomo (T final: 0,66+0,36 A), al compararse con sapos control (C final: 0,91+0,50 A) al final del experimento. De este modo, se concluye que los cambios debidos a las dosis analizadas de Pb en los niveles de anticuerpos no pueden explicarse sólo sobre la base de un único mecanismo de acción del metal, sino como resultado de una conjunción de efectos sobre diferentes subpoblaciones de células inmunocompetentes. Estas diferentes respuestas sugieren que los factores que afectan los animales expuestos a un estímulo externo son diferentes de aquellos que influyen la respuesta en los animales silvestres.Facultad de Ciencias ExactasComisión de Investigaciones Científicas de la provincia de Buenos Aire

Evaluation and additional recommendations for preparing a whole blood control material

Objective: The assessment of an easy to prepare and low cost control material for Hematology, available for manual and automated methods. Material and Method: Aliquots of stabilized whole blood were prepared by partial fixation with aldehydes; the stability at different temperatures (4. 20 and 37 °C) during periods of up to 8-9 weeks and aliquot variability with both methods were controlled. Results: Aliquot variability with automated methods at day 1, expressed as CV% (coefficient of variation) was: white blood cells (WBC) 2.7, red blood cells (RBC) 0.7, hemoglobin (Hb) 0.6, hematocrit (Hct) 0.7, mean cell volume (MCV) 0.3, mean cell hemoglobin (MCH) 0.6, mean cell hemoglobin concentration (MCHC) 0.7, and platelets (PLT) 4.6. The CV (coefficient of variation) percentages obtained with manual methods in one of the batches were: WBC 23, Hct 2.8, Hb 4.5, MCHC 5.9, PLT 41. Samples stored at 4ºC and 20ºC showed good stability, only a very low initial hemolysis being observed, whereas those stored at 37ºC deteriobed a rapidly (metahemoglobin formation, aggregation of WBC and platelets, as well as alteration of erythrocyte indexes). Conclusions: It was confirmed that, as long as there is no exposure to high temperatures during distribution, this material is stable, allowing assessment, both esternal and internal, for control purposes, with acceptable reproductivity, both for manual and auttomatic methods.Objetivo: Avaliar material de controle para hematologia, de fácil preparação e baixo custo, que poderá ser usado por métodos manuais e automatizados. Material e Método: Alíquotas de sangue estabilizado foram preparadas por fixação parcial com aldeídos. Foram estudadas a estabilidade a diferentes temperaturas (4, 20, 37ºC) durante períodos de até 8-9 semanas e a variabilidade das alíquotas para ambos os métodos. Resultados: A variabilidade entre alíquotas, expressada em CV% (coeficiente de variação) com métodos automatizados no primero dia, foi: glóbulos blancos (WBC) 2,7, glóbulos vermelhos (RBC) 0,7, hemoglobina (Hb) 0,6, hematócrito (Hct) 0,7, volume corpuscular médio (MCV) 0,3, Hb corpuscular médio (MCH) 0,3, concentração de Hb corpuscular médio (MCHC) 0,7 e plaquetas (Plt) 4,6. O CV% obtido com métodos manuais para um dos grupos foi: WBC 23, Hct 2,8, Hb 4,5, MCHC 5,9, Plt 41. As amostras conservadas a 4 e 20ºC foram estáveis, observando-se leve hemólise inicial, enquanto que as amostras conservadas a 37ºC mostraram uma rápida decomposição (formação de metaemoglobina, agregação de glóbulos brancos e plaquetas e alteração de índices). Conclusões: Confirmou-se que, se não houver exposição a altas temperaturas durante a distribuição, este material é estável, permitindo avaliação, tanto externa como interna para controle e com reprodutividade aceitável, tanto para métodos manuais como automáticos. Sangue. Controle de qualidade. Laboratórios.observed, whereas those stored at 37ºC deteriobed a rapidly (metahemoglobin formation, aggregation of WBC and platelets, as well as alteration of erythrocyte indexes). Conclusions It was confirmed that, as long as there is no exposure to high temperatures during distribution, this material is stable, allowing assessment, both esternal and internal, for control purposes, with acceptable reproductivity, both for manual and auttomatic methods.Facultad de Ciencias Exacta

Biosensors of inorganic lead exposure and effect in an adult amphibian

Lead (Pb) is a ubiquitous environmental pollutant, widely distributed, representing a high toxicological and ecotoxicological risk. Several morphological, functional, and biochemical parameters have been proposed as biomarkers of effect and exposure to Pb. The information related to adverse effects of Pb is not abundant for adult amphibians. These animals are of interest, because during their development they move from aquatic to terrestrial habitats, which may be polluted by the metal since they are receptors of products generated by anthropogenic activities. Previous studies carried out on the adult South American toad Bufo arenarum (Amphibia, Anura) showed that it has a high tolerance to lead and studied the effect of sublethal doses of the metal on the erythrocyte osmotic fragility and δ-ALAD activity. It was also shown that after a single injection of Pb, a significant increase in the number of reticulocytes was produced, suggesting the suitability of those cell counts as a biomarker of exposure to the metal; its impact on the immune system of the toads was also studied. In this work we extend our early studies on the same species evaluating the chronic effect of sublethal Pb (equivalent to 5.6% of the 120-h LD-50) on free erythrocyte protoporphyrin (FEP) and blood Pb and δ-ALAD activity; blood lead was positively associated with a significant decrease in the enzyme activity and to an increase in the FEP level. Pb concentration in target organs (liver, spleen, femur, and kidney) and the total cumulated amount as well as its impact over the mass of those organs were also determined. In addition, the magnitude of the possible depuration through urine and intestine was evaluated. Our results showed that FEP, δ-ALAD, and blood Pb are reliable biosensors of chronic metal intoxication, the former being the marker with the highest sensitivity.Facultad de Ciencias Exacta

Determinação de ferro sérico: evolução do desempenho dos laboratórios participantes do Sub-Programa PEEC-hematologia

El objetivo de este trabajo fue determinar la evolución del desempeño analítico en la determinación de hierro sérico, de los laboratorios participantes del Sub- Programa PEEC-Hematología (PEEC-H) del Programa de Evaluación Externa de Calidad Prof. Dr. Daniel Mazziotta de la Fundación Bioquímica Argentina, mediante el análisis de los resultados de ferremia en 6 encuestas (E) realizadas en los meses de julio entre los años 2010 y 2015 (E 77, 81, 85, 89, 93 y 97). Hasta el 2011 se utilizaban métodos con y sin desproteinización, siendo estos últimos los más utilizados (94%). En 2015 en la red de laboratorios se emplearon solamente métodos directos sin desproteinización, siendo los colorimétricos los más utilizados (aproximadamente 95%). El Desvío Relativo Porcentual aceptable (DRPa) fue de ±10% en todas las encuestas analizadas. El 56% de los laboratorios tuvieron un desempeño promedio aceptable en las E 77, 81 y 85, evolucionando 3 años después, a 70% en las E 89, 93 y 97. Según estas consideraciones, al presente no es necesario ajustar el DRPa para el analito hierro, ya que con este valor los laboratorios aún deben trabajar para lograr una mejoría en su desempeño.The aim of this work was to evaluate the evolution of the analytical performance of serum iron determination by the laboratories participating in the Sub- Program PEEC-Hematology (PEEC-H) EQAS Program Prof. Dr. Daniel Mazziotta of the Argentine Biochemical Foundation. To this end, results of serum iron determinations from July 2010 to July 2015 (surveys #77, 81, 85, 89, 93 and 97) were used. Up to 2011, there were methods both with and without deproteinization, the latter being the most used (94%). In 2015, only one commercial method without deproteinization was used, with colorimetric methods employed in 95% of the cases. In all the surveys analyzed, the acceptable DRP was ±10%. In surveys 77, 81 and 85, 56% of the laboratories had an acceptable performance percentage, and it evolved to a 70% in the surveys 89, 93 and 97, three years later. According to these considerations, there is no need to adjust the acceptable DRP for the iron analyte. In this way, laboratories will continue to work in order to improve their performance.Facultad de Ciencias Exacta

Determinação de ferro sérico: evolução do desempenho dos laboratórios participantes do Sub-Programa PEEC-hematologia

El objetivo de este trabajo fue determinar la evolución del desempeño analítico en la determinación de hierro sérico, de los laboratorios participantes del Sub- Programa PEEC-Hematología (PEEC-H) del Programa de Evaluación Externa de Calidad Prof. Dr. Daniel Mazziotta de la Fundación Bioquímica Argentina, mediante el análisis de los resultados de ferremia en 6 encuestas (E) realizadas en los meses de julio entre los años 2010 y 2015 (E 77, 81, 85, 89, 93 y 97). Hasta el 2011 se utilizaban métodos con y sin desproteinización, siendo estos últimos los más utilizados (94%). En 2015 en la red de laboratorios se emplearon solamente métodos directos sin desproteinización, siendo los colorimétricos los más utilizados (aproximadamente 95%). El Desvío Relativo Porcentual aceptable (DRPa) fue de ±10% en todas las encuestas analizadas. El 56% de los laboratorios tuvieron un desempeño promedio aceptable en las E 77, 81 y 85, evolucionando 3 años después, a 70% en las E 89, 93 y 97. Según estas consideraciones, al presente no es necesario ajustar el DRPa para el analito hierro, ya que con este valor los laboratorios aún deben trabajar para lograr una mejoría en su desempeño.The aim of this work was to evaluate the evolution of the analytical performance of serum iron determination by the laboratories participating in the Sub- Program PEEC-Hematology (PEEC-H) EQAS Program Prof. Dr. Daniel Mazziotta of the Argentine Biochemical Foundation. To this end, results of serum iron determinations from July 2010 to July 2015 (surveys #77, 81, 85, 89, 93 and 97) were used. Up to 2011, there were methods both with and without deproteinization, the latter being the most used (94%). In 2015, only one commercial method without deproteinization was used, with colorimetric methods employed in 95% of the cases. In all the surveys analyzed, the acceptable DRP was ±10%. In surveys 77, 81 and 85, 56% of the laboratories had an acceptable performance percentage, and it evolved to a 70% in the surveys 89, 93 and 97, three years later. According to these considerations, there is no need to adjust the acceptable DRP for the iron analyte. In this way, laboratories will continue to work in order to improve their performance.Facultad de Ciencias Exacta