Comparison of Asymptomatic and Symptomatic Adverse Local Tissue Reaction in Patients With Head-Neck Taper Corrosion.

BACKGROUND: Diagnosis of adverse local tissue reaction (ALTR) in metal-on-polyethylene (MoP) total hip arthroplasty (THA) secondary to head-neck taper corrosion is challenging. The purpose of this study is to compare differences between asymptomatic and symptomatic ALTR in an observational cohort, including presentation, metal ion differences, and metal artifact reduction sequence (MARS) magnetic resonance imaging (MRI) findings. METHODS: We performed a retrospective review of an observational cohort of 492 MoP THA patients at increased risk of developing ALTR. Ninety-four patients underwent revision arthroplasty for ALTR. Patients were stratified into symptomatic and asymptomatic ALTR groups. Presentation, metal ion levels, and imaging findings were compared. RESULTS: For patients with confirmed ALTR, 41% were asymptomatic. There was a statistically significant difference in the serum chromium levels between symptomatic and asymptomatic ALTR patients (2.2 µg/L vs 3.1 µg/L, P = .05). There was no statistically significant difference between the serum cobalt levels or MRI findings in these 2 groups. We observed that extracapsular disease associated with ALTR could be misinterpreted as trochanteric bursitis. CONCLUSION: Almost half of the MoP THA ALTR cases identified were asymptomatic. Cobalt levels could not differentiate between symptomatic and asymptomatic pseudotumor formation. Symptomatic and asymptomatic MoP ALTRs have similar MARS MRI characteristics. Our findings suggest that it is essential to risk stratify patients who could potentially have ALTR based on implant type, symptoms, ion levels, and MARS MRI.

[Allergic contact dermatitis to cobalt and nickel in a metal industry worker. Case report and literature review]. / Dermatitis de contacto alérgica a cobalto y níquel en un trabajador de la industria metalúrgica. Reporte de caso y revisión de la literatura.

BACKGROUND: Contact dermatitis is an eczematous skin reaction that is caused by repeated and direct exposure to an allergen: The prevalence of contact dermatitis to nickel is estimated at 17% in women and 3% in men, and 1-3% of the general population has allergic contact dermatitis to cobalt and chromium. Nickel, which is the leading cause of occupational dermatitis, shows reactivity to other metals; mainly chromium and cobalt. CLINICAL CASE: A 47-year old man, with previous sensitization to nickel in childhood, is a worker in the metal industry, with occupational exposure to nickel and cobalt, and showed dermatosis predominantly in the upper limbs. CONCLUSION: The risk of new sensitizations to metals (such as cobalt) has been increased by his previous sensitization to nickel that happened in childhood and his work in the metal industry.

Antecedentes: La dermatitis por contacto es una reacción eccematosa en piel causada por la exposición repetida y directa de un alérgeno; se estima que la prevalencia de dermatitis de contacto al níquel es de 17 % en mujeres y 3 % en hombres y que 1 a 3 % de la población general presenta dermatitis de contacto alérgica a cobalto y cromo. El níquel es la causa más importante de dermatitis ocupacional y presenta reactividad a otros metales, principalmente cromo y cobalto. Caso clinico: Hombre de 47 años, con previa sensibilización a níquel en la infancia, trabajador de la industria metalúrgica, con exposición laboral a níquel y cobalto, quien presentó dermatosis de predominio en miembros superiores. Conclusión: La sensibilización previa a níquel en la infancia y el trabajo en la industria metalúrgica incrementó el riesgo de nuevas sensibilizaciones a metales, como cobalto.

Chromium(III), chromium(VI) and cobalt release from leathers produced in Nicaragua.

BACKGROUND: Leather exposure has been associated with chromium (Cr) and cobalt (Co) contact dermatitis. Cr(VI) in leather is now restricted to <3 mg/kg in the EU. Cr(III) is not restricted. OBJECTIVES: To analyse 29 differently coloured Cr-tanned leather samples from two Nicaraguan tanneries, and to compare their release of Cr, Cr(VI) and Co with that of leathers produced in Europe. METHODS: Cr, Cr(VI) and Co were extracted in phosphate buffer for 3 hours at 25°C according to EN ISO 17075. Atomic absorption spectroscopy and spectrophotometry were used for detection of the metals in phosphate buffer. RESULTS: There was no difference in total Cr or Cr(VI) release between European and Nicaraguan leathers. There was no association between Cr(VI) and total Cr release. Co was released primarily from leathers of one tannery. Cr(III) was released in significantly higher amounts than Cr(VI). CONCLUSIONS: Future investigations and regulations should focus on Cr(III) and Co as well as on Cr(VI).

Nickel, chromium and cobalt: the relevant allergens in allergic contact dermatitis. Comparative study between two periods: 1995-2002 and 2003-2015.

BACKGROUND: Metals are common agents of allergic contact dermatitis, occupational or not, with decreasing incidence over the last years in some countries that have regulated the amount of nickel in objects. OBJECTIVES: To analyze and compare with previous studies the profile of metal sensitization between 2003-2015. METHODS: Patients who underwent patch testing between 2003-2015 were evaluated retrospectively regarding the sensitization rates to metals, the associations between them, the relationship with profession and epidemiology. RESULTS: Of the 1,386 patients tested, 438 (32%) had positive test to some metal, similar results to the 404/1,208 (33%) of the previous study (1995-2002) performed at the same service (p=0.32). The frequency of nickel (77%), cobalt (32%) and chromium (29%) changed slightly (p=0.20). Most cases of sensitization to chromium were related to the occupation (64%), in contrast to nickel and cobalt (p<0.0001). There was a predominance of females among those sensitized to metal in both studies (p=0.63) and the age group of 20-49 years old (p=0.11); the number of fair-skinned individuals increased (p<0.001), as well as the lesions in the cephalic segment (50.5%; p<0.0001) and hands (45%; p<0.0001), which are not the most frequent location anymore. The number of cleaners decreased (39% vs. 59%; p<0.0001), which still lead in front of bricklayers/painters, which increased (14% vs. 9%; p=0.013). The frequency of wet work reduced (65% vs. 81%; p<0.0001). STUDY LIMITATIONS: The study included a single population group; only patients with positive tests to metals were considered - the others were not evaluated for the possibility of false negatives. CONCLUSION: The sensitization to metals, occupational or not, has been significant over the last 21 years, with few epidemiological changes.

Evaluation of nickel and cobalt release from mobile phone devices used in Brazil.

Nickel and cobalt are often responsible for metal-induced allergic contact dermatitis. With the increasing use of cell phones, we observed an increase in cases reports on telephone-related allergic contact dermatitis. The present study evaluated nickel and cobalt release from mobile phones used in Brazil. We evaluated devices of 6 brands and 20 different models using nickel and cobalt allergy spot tests. Of the 20 models, 64.7% tested positive for nickel, with 41.1% positive results for the charger input and 23.5% for other tested areas. None of them was positive for cobalt. Nickel release was more common in older models.

Nickel, chromium and cobalt: the relevant allergens in allergic contact dermatitis. Comparative study between two periods: 1995-2002 and 2003-2015

Abstract: Background: Metals are common agents of allergic contact dermatitis, occupational or not, with decreasing incidence over the last years in some countries that have regulated the amount of nickel in objects. Objectives: To analyze and compare with previous studies the profile of metal sensitization between 2003-2015. Methods: Patients who underwent patch testing between 2003-2015 were evaluated retrospectively regarding the sensitization rates to metals, the associations between them, the relationship with profession and epidemiology. Results: Of the 1,386 patients tested, 438 (32%) had positive test to some metal, similar results to the 404/1,208 (33%) of the previous study (1995-2002) performed at the same service (p=0.32). The frequency of nickel (77%), cobalt (32%) and chromium (29%) changed slightly (p=0.20). Most cases of sensitization to chromium were related to the occupation (64%), in contrast to nickel and cobalt (p<0.0001). There was a predominance of females among those sensitized to metal in both studies (p=0.63) and the age group of 20-49 years old (p=0.11); the number of fair-skinned individuals increased (p<0.001), as well as the lesions in the cephalic segment (50.5%; p<0.0001) and hands (45%; p<0.0001), which are not the most frequent location anymore. The number of cleaners decreased (39% vs. 59%; p<0.0001), which still lead in front of bricklayers/painters, which increased (14% vs. 9%; p=0.013). The frequency of wet work reduced (65% vs. 81%; p<0.0001). Study limitations: The study included a single population group; only patients with positive tests to metals were considered - the others were not evaluated for the possibility of false negatives. Conclusion: The sensitization to metals, occupational or not, has been significant over the last 21 years, with few epidemiological changes.

Evaluation of nickel and cobalt release from mobile phone devices used in Brazil

Abstract: Nickel and cobalt are often responsible for metal-induced allergic contact dermatitis. With the increasing use of cell phones, we observed an increase in cases reports on telephone-related allergic contact dermatitis. The present study evaluated nickel and cobalt release from mobile phones used in Brazil. We evaluated devices of 6 brands and 20 different models using nickel and cobalt allergy spot tests. Of the 20 models, 64.7% tested positive for nickel, with 41.1% positive results for the charger input and 23.5% for other tested areas. None of them was positive for cobalt. Nickel release was more common in older models.

Hard metal lung disease: a case series / Doença pulmonar por metal duro: uma série de casos

ABSTRACT Objective: To describe diagnostic and treatment aspects of hard metal lung disease (HMLD) and to review the current literature on the topic. Methods: This was a retrospective study based on the medical records of patients treated at the Occupational Respiratory Diseases Clinic of the Instituto do Coração, in the city of São Paulo, Brazil, between 2010 and 2013. Results: Of 320 patients treated during the study period, 5 (1.56%) were diagnosed with HMLD. All of those 5 patients were male (mean age, 42.0 ± 13.6 years; mean duration of exposure to hard metals, 11.4 ± 8.0 years). Occupational histories were taken, after which the patients underwent clinical evaluation, chest HRCT, pulmonary function tests, bronchoscopy, BAL, and lung biopsy. Restrictive lung disease was found in all subjects. The most common chest HRCT finding was ground glass opacities (in 80%). In 4 patients, BALF revealed multinucleated giant cells. In 3 patients, lung biopsy revealed giant cell interstitial pneumonia. One patient was diagnosed with desquamative interstitial pneumonia associated with cellular bronchiolitis, and another was diagnosed with a hypersensitivity pneumonitis pattern. All patients were withdrawn from exposure and treated with corticosteroid. Clinical improvement occurred in 2 patients, whereas the disease progressed in 3. Conclusions: Although HMLD is a rare entity, it should always be included in the differential diagnosis of respiratory dysfunction in workers with a high occupational risk of exposure to hard metal particles. A relevant history (clinical and occupational) accompanied by chest HRCT and BAL findings suggestive of the disease might be sufficient for the diagnosis.

RESUMO Objetivo: Descrever aspectos relacionados ao diagnóstico e tratamento de pacientes com doença pulmonar por metal duro (DPMD) e realizar uma revisão da literatura. Métodos: Estudo retrospectivo dos prontuários médicos de pacientes atendidos no Serviço de Doenças Respiratórias Ocupacionais do Instituto do Coração, localizado na cidade de São Paulo, entre 2010 e 2013. Resultados: Entre 320 pacientes atendidos no período do estudo, 5 (1,56%) foram diagnosticados com DPMD. Todos os pacientes eram do sexo masculino, com média de idade de 42,0 ± 13,6 anos e média de tempo de exposição a metal duro de 11,4 ± 8,0 anos. Os pacientes foram submetidos a avaliação clinica, história ocupacional, TCAR de tórax, prova de função pulmonar, broncoscopia com LBA e biópsia pulmonar. Todos apresentaram distúrbio ventilatório restritivo. O achado de imagem à TCAR de tórax mais frequente foi de opacidades em vidro fosco (em 80%). Em 4 pacientes, o LBA revelou presença de células gigantes multinucleadas. Em 3, foi diagnosticada pneumonia intersticial por células gigantes na biópsia pulmonar. Houve o diagnóstico de pneumonia intersticial descamativa associada à bronquiolite celular em 1 paciente e de pneumonite de hipersensibilidade em 1. Todos foram afastados da exposição e tratados com corticoide. Houve melhora em 2 pacientes e progressão da doença em 3. Conclusões: Apesar de ser uma entidade rara, a DPMD deve ser sempre considerada em trabalhadores com risco ocupacional elevado de exposição a metais duros. A história clínica e ocupacional associada a achados em TCAR de tórax e LBA sugestivos da doença podem ser suficientes para o diagnóstico.

Hard metal lung disease: a case series.

OBJECTIVE:: To describe diagnostic and treatment aspects of hard metal lung disease (HMLD) and to review the current literature on the topic. METHODS:: This was a retrospective study based on the medical records of patients treated at the Occupational Respiratory Diseases Clinic of the Instituto do Coração, in the city of São Paulo, Brazil, between 2010 and 2013. RESULTS:: Of 320 patients treated during the study period, 5 (1.56%) were diagnosed with HMLD. All of those 5 patients were male (mean age, 42.0 ± 13.6 years; mean duration of exposure to hard metals, 11.4 ± 8.0 years). Occupational histories were taken, after which the patients underwent clinical evaluation, chest HRCT, pulmonary function tests, bronchoscopy, BAL, and lung biopsy. Restrictive lung disease was found in all subjects. The most common chest HRCT finding was ground glass opacities (in 80%). In 4 patients, BALF revealed multinucleated giant cells. In 3 patients, lung biopsy revealed giant cell interstitial pneumonia. One patient was diagnosed with desquamative interstitial pneumonia associated with cellular bronchiolitis, and another was diagnosed with a hypersensitivity pneumonitis pattern. All patients were withdrawn from exposure and treated with corticosteroid. Clinical improvement occurred in 2 patients, whereas the disease progressed in 3. CONCLUSIONS:: Although HMLD is a rare entity, it should always be included in the differential diagnosis of respiratory dysfunction in workers with a high occupational risk of exposure to hard metal particles. A relevant history (clinical and occupational) accompanied by chest HRCT and BAL findings suggestive of the disease might be sufficient for the diagnosis. OBJETIVO:: Descrever aspectos relacionados ao diagnóstico e tratamento de pacientes com doença pulmonar por metal duro (DPMD) e realizar uma revisão da literatura. MÉTODOS:: Estudo retrospectivo dos prontuários médicos de pacientes atendidos no Serviço de Doenças Respiratórias Ocupacionais do Instituto do Coração, localizado na cidade de São Paulo, entre 2010 e 2013. RESULTADOS:: Entre 320 pacientes atendidos no período do estudo, 5 (1,56%) foram diagnosticados com DPMD. Todos os pacientes eram do sexo masculino, com média de idade de 42,0 ± 13,6 anos e média de tempo de exposição a metal duro de 11,4 ± 8,0 anos. Os pacientes foram submetidos a avaliação clinica, história ocupacional, TCAR de tórax, prova de função pulmonar, broncoscopia com LBA e biópsia pulmonar. Todos apresentaram distúrbio ventilatório restritivo. O achado de imagem à TCAR de tórax mais frequente foi de opacidades em vidro fosco (em 80%). Em 4 pacientes, o LBA revelou presença de células gigantes multinucleadas. Em 3, foi diagnosticada pneumonia intersticial por células gigantes na biópsia pulmonar. Houve o diagnóstico de pneumonia intersticial descamativa associada à bronquiolite celular em 1 paciente e de pneumonite de hipersensibilidade em 1. Todos foram afastados da exposição e tratados com corticoide. Houve melhora em 2 pacientes e progressão da doença em 3. CONCLUSÕES:: Apesar de ser uma entidade rara, a DPMD deve ser sempre considerada em trabalhadores com risco ocupacional elevado de exposição a metais duros. A história clínica e ocupacional associada a achados em TCAR de tórax e LBA sugestivos da doença podem ser suficientes para o diagnóstico.

Administração de propilenoglicol, cobalto e vitamina B12 às ovelhas e seus reflexos sobre o perfil eletroforético das proteínas séricas nas suas crias / Administration of propylene glycol, cobalt and vitamin B12 to sheep and its effects on the electrophoretic profile of serum proteins of the lambs

Este trabalho foi desenvolvido com o objetivo de avaliar a influência da administração de propilenoglicol, cobalto e vitamina B12, sobre o perfil eletroforético das proteínas séricas nas ovelhas e respectivas crias. O estudo foi realizado utilizando-se 18 ovelhas prenhes que foram divididas em grupos de forma aleatória aos 30 dias antes da data prevista para o parto, para serem fornecidos os suplementos até o momento antecedente ao parto. Os grupos foram os seguintes: Grupo 1 (G1/n=6) Grupo Controle; Grupo 2 (G2/n=6) Grupo Cobalto e Vitamina B12 (em que foi fornecido 1mg de cobalto via oral diariamente e 2 mg de vitamina B12 via intramuscular semanalmente); e Grupo 3 (G3/n=6) Grupo Propilenoglicol (administração de 30 mL de propilenoglicol via oral diariamente). Com isso, pôde-se observar que as frações proteicas em sua maioria sofrem variações com o desenvolvimento etário, em especial as proteínas totais séricas, albumina, beta-globulina e gama-globulina e o fator determinante para essas variações foi a ingestão do colostro. Além disso, não houve influência da ingestão dos componentes pelas ovelhas sobre o perfil destas variáveis nos borregos.

This work was carried out to evaluate the influence of administration of propilene glycol, cobalt and vitamin B12, on the electrophoretic profile of serum proteins on sheep and their offspring. The study was conducted using 18 pregnant ewes which were randomly divided into groups at 30 days before the date scheduled for delivery in order to be given supplements until the date preceding the birth. The groups were as follows: Group 1 (G1/n=6) Control Group; Group 2 (G2/n=6) Cobalt and Vitamin B12 (wich was received 1mg of cobalt orally daily and 2mg of vitamin B12, intramuscularly weeckly); and Group 3 (G3/n=6) Propylene Glycol (administration of 30mL of propylene glycol orally daily). We observed that mosto f the protein fractions vary with age development, particularly total serum protein, albumin, beta-globulin and gamma-globulin, and the determinant factor for these changes is colostrum intake. Furthermore, there was no influence of intake by sheep of the components studied on the profile of these variables in lambs.

Administração de propilenoglicol, cobalto e vitamina B12 às ovelhas e seus reflexos sobre o perfil eletroforético das proteínas séricas nas suas crias / Administration of propylene glycol, cobalt and vitamin B12 to sheep and its effects on the electrophoretic profile of serum proteins of the lambs

Este trabalho foi desenvolvido com o objetivo de avaliar a influência da administração de propilenoglicol, cobalto e vitamina B12, sobre o perfil eletroforético das proteínas séricas nas ovelhas e respectivas crias. O estudo foi realizado utilizando-se 18 ovelhas prenhes que foram divididas em grupos de forma aleatória aos 30 dias antes da data prevista para o parto, para serem fornecidos os suplementos até o momento antecedente ao parto. Os grupos foram os seguintes: Grupo 1 (G1/n=6) Grupo Controle; Grupo 2 (G2/n=6) Grupo Cobalto e Vitamina B12 (em que foi fornecido 1mg de cobalto via oral diariamente e 2 mg de vitamina B12 via intramuscular semanalmente); e Grupo 3 (G3/n=6) Grupo Propilenoglicol (administração de 30 mL de propilenoglicol via oral diariamente). Com isso, pôde-se observar que as frações proteicas em sua maioria sofrem variações com o desenvolvimento etário, em especial as proteínas totais séricas, albumina, beta-globulina e gama-globulina e o fator determinante para essas variações foi a ingestão do colostro. Além disso, não houve influência da ingestão dos componentes pelas ovelhas sobre o perfil destas variáveis nos borregos.(AU)

This work was carried out to evaluate the influence of administration of propilene glycol, cobalt and vitamin B12, on the electrophoretic profile of serum proteins on sheep and their offspring. The study was conducted using 18 pregnant ewes which were randomly divided into groups at 30 days before the date scheduled for delivery in order to be given supplements until the date preceding the birth. The groups were as follows: Group 1 (G1/n=6) Control Group; Group 2 (G2/n=6) Cobalt and Vitamin B12 (wich was received 1mg of cobalt orally daily and 2mg of vitamin B12, intramuscularly weeckly); and Group 3 (G3/n=6) Propylene Glycol (administration of 30mL of propylene glycol orally daily). We observed that mosto f the protein fractions vary with age development, particularly total serum protein, albumin, beta-globulin and gamma-globulin, and the determinant factor for these changes is colostrum intake. Furthermore, there was no influence of intake by sheep of the components studied on the profile of these variables in lambs.(AU)

Contact sensitivity to metals (chromium, cobalt and nickel) in childhood.

Metals, especially nickel, are the most common contact allergens in children. Recent data has shown increased incidence of allergy in industrialized countries. Sensitization can occur at any age, even in neonates. Costume jewelry, particularly earrings, is linked to increased sensitization to nickel. Sensitization to cobalt often occurs by the use of costume jewelry. The most common source of sensitization to chromium is leather. Due to the absence of a specific therapy, the main treatment is to identify and avoid the responsible allergens. This article presents an updated view on the epidemiological and clinical aspects of contact allergy to metals, focusing on prevention strategies and risk factors, and warns about possible and new sources of contact.

Contact sensitivity to metals (chromium, cobalt and nickel) in childhood / Alergia de contato aos metais (cromo, cobalto e níquel) na infância

Metals, especially nickel, are the most common contact allergens in children. Recent data has shown increased incidence of allergy in industrialized countries. Sensitization can occur at any age, even in neonates. Costume jewelry, particularly earrings, is linked to increased sensitization to nickel. Sensitization to cobalt often occurs by the use of costume jewelry. The most common source of sensitization to chromium is leather. Due to the absence of a specific therapy, the main treatment is to identify and avoid the responsible allergens. This article presents an updated view on the epidemiological and clinical aspects of contact allergy to metals, focusing on prevention strategies and risk factors, and warns about possible and new sources of contact.

Os metais, especialmente o níquel, são os sensibilizantes de contato mais comuns em crianças. Dados recentes revelam aumento na incidência da alergia deste em países industrializados. A sensibilização pode ocorrer em qualquer idade, mesmo em recém-nascidos. Bijuterias, especialmente brincos nas orelhas, são ligadas ao aumento da sensibilização ao níquel. A sensibilização ao cobalto geralmente ocorre pelo uso de bijuterias. A fonte mais comum de sensibilização ao cromo é o couro. Devido à ausência de terapia específica, o principal tratamento consiste em identificar e evitar os alérgenos responsáveis. Este artigo pretende apresentar uma visão atualizada sobre os aspectos epidemiológicos e clínicos da alergia de contato aos metais, focando estratégias de prevenção e fatores de risco, além de alertar sobre as possíveis e novas fontes de contato.

Hypersensitivity to metals in orthodontics.

To study the incidence of hypersensitivity to orthodontic metals, patch tests were carried out before and 2 months after the placement of orthodontic appliances in 38 patients (17 male, 21 female). The tested substances were cobalt chloride, copper sulfate, potassium dichromate, iron sulfate, manganese chloride, molybdenum salt, nickel sulfate, and titanium oxide. Eight strips containing the test substances were positioned on the patients' backs. They were removed after 48 hours and assessed by a dermatologist at 48 and 72 hours after antigen application. The obtained data were analyzed by the chi-square test and McNemar's chi-square test. Statistically significant positive reactions were observed for nickel sulfate (21.1%), potassium dichromate (21.1%), and manganese chloride (7.9%); reactions to nickel sulfate had the greatest intensity. No differences were observed between the reactions before and after placement of the orthodontic appliances; this indicates that they did not sensitize the patients or affect their tolerance to these metals during the study period. No statistical difference was observed regarding sex for any evaluated substance, although a greater tendency to positivity to nickel sulfate was observed among female patients and to potassium dichromate in male patients.

Excessive erythrocytosis, chronic mountain sickness, and serum cobalt levels.

In a subset of high-altitude dwellers, the appropriate erythrocytotic response becomes excessive and can result in chronic mountain sickness. We studied men with (study group) and without excessive erythrocytosis (packed-cell volume >65%) living in Cerro de Pasco, Peru (altitude 4300 m), and compared them with controls living in Lima, Peru (at sea-level). Toxic serum cobalt concentrations were detected in 11 of 21 (52%) study participants with excessive erythrocytosis, but were undetectable in high altitude or sea-level controls. In the mining community of Cerro de Pasco, cobalt toxicity might be an important contributor to excessive erythrocytosis.

Expresión de CCL2 y CS-1 fibronectina en dermatitis alérgica por contacto / Expression of human CCL2 and CS-1 fibronectin in allergic contact dermatitis

Antecedentes: si bien la dermatitis alérgica por contacto (DAC) es una dermatosis humana frecuente, no todos los mecanismos involucrados en su patogenia han sido dilucidados. Objetivo: estudiar la cinética de expresión de CCL2, CS-1 fibronectina y CCL17 en biopsias de reacciones provocadas por pruebas de parches. Diseño: diez pacientes diagnosticados con DAC fueron desafiados en la espalda con antígenos inductores e irrelevantes. A las 2, 10 y 48 horas se observaron las respuestas macroscópicas y se obtuvieron biopsias, las cuales fueron procesadas para realizar estudios histológicos, inmunohistoquímicos y de hibridización in situ. Resultados: todos los individuos presentaron a las 48 horas una respuesta clínica positiva y un infiltrado celular mononuclear perivascular, el cual no fue observado en los controles negativos. ARNm para CCL2 fue encontrado solamente en sitios positivos a las 10 y 48 horas. Los endotelios inflamados expresaron CS-1 fibronectina y CCL17. El número de células CD+ y CD68+ aumentó significativamente con el tiempo en los parches positivos (p<0,0001). En éstos mismos sitios las células infiltrantes CCR5+ y CXCR3+, pero no las CCR3+ también incrementaron significativamente entre las 2 y 10 horas (p<0,03), y a las 48 horas, el porcentaje de células CCR5+ y CXCR3+ a las 10 y 48 horas (rs=0,9; p=0,0007). Conclusión: éste estudio demuestra por primera vez la producción de CCL2 y CS-1 fibronectina en la piel de pacientes con DAC en respuesta al desafío antigénico específico (AU)

Fibrohistiocitoma maligno sobre radiodermitis / Malignant fibrous histiocytoma over radiodermitis

Se prsentan dos casos clínicos de fibrohistiocitoma maligno sobre radiodermitis. El primer caso se trata de un paciente de sexo masculino que presenta una lesión tumoral en mejilla derecha, zona de radiodermatitis crónica provocada por tratamiento de acné 25 años atrás. Luego de la escisión quirúrgica la lesión recidivaal año. En el segundo caso una paciente de sexo femenino portadora de carcinoma mamario presenta una lesión tumoral compatible con fibrohistiocitoma maligno localizada en cara anterior de tórax, sobre una radiodermitis crónica por tratamiento de cobalto realizado por su patología de base 23 años atrás. Se derivó al srvicio de cirugía, pero la paciente fallece antes por metástasis del carcinoma. Dada la escasa frecuencia de esta patología se realiza una revisión bibliográfica del tema