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Neurohistoplasmosis is a rare disease, most prevalent in immunosuppressed patients, secondary to disseminated disease with a high mortality rate when diagnosis and treatment are delayed. We report a previously healthy 12 year old girl, from a bat infested region of Tucuman Province, Argentine Republic, who developed meningoencephalitis due to Histoplasma capsulatum. Eighteen months prior to admission the patient started with headaches and intermittent fever. The images of the central nervous system showed meningoencephalitis suggestive of tuberculosis. She received antibiotics and tuberculostatic medications without improvement. Liposomal amphotericin B was administered for six weeks. The patient's clinical status improved remarkably. Finally the culture of cerebral spinal fluid was positive for micelial form of Histoplasma capsulatum. The difficulties surrounding the diagnosis and treatment of neurohistoplasmosis in immunocompetent patients are discussed in this manuscript, as it also intends to alert to the presence of a strain of Histoplasma capsulatum with affinity for the central nervous system.

Paracoccidioidomycosis is an endemic fungal disease widely distributed throughout Latin America. The potent immunosuppressor cyclophosphamide (CY) has been used to modulate host immune response to Paracoccidioides brasiliensis in an experimental model. Inbred male Buffalo/Sim rats weighing 250-300 g were inoculated with 5 x 10(6) P. brasiliensis cells of the yeast phase form by intracardiac route. One group of animals was treated with 20 mg/kg body weight at days +4, +5, +6, +7, +11 and +12 post-infection (pi.), while a control group was infected alone. No mortality was recorded in either group. Treated rats presented: a) a decrease in granuloma size, which contained less fungal cells; b) a lack of specific antibodies up to 35 days pi., and c) a significant increase in the footpad swelling test (DTH) against paracoccidioidin. Splenic cell transfer from CY-treated P. brasiliensis-infected donors to recipients infected alone led to a significant increase in DTH response in the latter versus untreated infected controls. Likewise, in treated infected recipients transferred with untreated infected donor spleen cells, footpad swelling proved greater than in controls. Thus, it would seem that each successive suppressor T lymphocyte subset belonging to the respective cascade may be sensitive to repeated CY doses administered up to 12 days pi.. Alternatively, such CY schedule may induce the appearance of a T cell population capable of amplifying DTH response. La paracoccidioidomicosis es una enfermedad endémica fúngica ampliamente distribuida en Latino-América. La ciclofosfamida ha sido usada como potente inmunosupresor para modular la respuesta inmune, en un modelo experimental infectado con Paracoccidioides brasiliensis. Ratas machos Buffalo/Sim endocriadas de 250-300 gr. de peso, fueron inoculadas por via intracardiaca con 5.10 6 células de P. brasiliensis en fase levaduriforme. Un grupo de animales fue tratado con 20 mg/kg de peso de ciclofosfamida en los dias +4, +5, +6, +7, +11 y +12 p. i. mientras que un grupo control fue infectado solaménte. No se registró mortalidad en ninguno de los grupos. Las ratas tratadas presentaron: a) una disminución en el tamaño del granuloma, el cual contenia menor cantidad de células fúngicas; b) ausencia de anticuerpos específicos hasta los 35 dias p.i. y c) un aumento significativo en el test de hinchazón de la pata (DTH) contra la paracoccidioidina. Células esplénicas provenientes de dadores infectados con P. brasiliensis fueron transferidas a receptores infectados solamente, lo que produjo un aumento significativo de la DTH en estos últimos con respecto a los controles. Asi mismo, células esplénicas de dadores infectados solamente fueron transferidas a receptores infectados y tratados mostrando tambien un aumento en la DTH con respecto a los controles. Cada uno de los linfocitos T supresores pertenecientes a la cascada de células T parecerian ser sensibles a dosis sucesivas de ciclofosfamida hasta los 12 dias p.i.. Por otra parte, el esquema de tratamiento con ciclofosfamida podria inducir la aparición de una población de células T capaces de amplificar la respuesta DTH

Paracoccidioidomycosis is an endemic fungal disease widely distributed throughout Latin America. The potent immunosuppressor cyclophosphamide (CY) has been used to modulate host immune response to Paracoccidioides brasiliensis in an experimental model. Inbred male Buffalo/Sim rats weighing 250-300 g were inoculated with 5 x 10(6) P. brasiliensis cells of the yeast phase form by intracardiac route. One group of animals was treated with 20 mg/kg body weight at days +4, +5, +6, +7, +11 and +12 post-infection (pi.), while a control group was infected alone. No mortality was recorded in either group. Treated rats presented: a) a decrease in granuloma size, which contained less fungal cells; b) a lack of specific antibodies up to 35 days pi., and c) a significant increase in the footpad swelling test (DTH) against paracoccidioidin. Splenic cell transfer from CY-treated P. brasiliensis-infected donors to recipients infected alone led to a significant increase in DTH response in the latter versus untreated infected controls. Likewise, in treated infected recipients transferred with untreated infected donor spleen cells, footpad swelling proved greater than in controls. Thus, it would seem that each successive suppressor T lymphocyte subset belonging to the respective cascade may be sensitive to repeated CY doses administered up to 12 days pi.. Alternatively, such CY schedule may induce the appearance of a T cell population capable of amplifying DTH response. La paracoccidioidomicosis es una enfermedad endémica fúngica ampliamente distribuida en Latino-América. La ciclofosfamida ha sido usada como potente inmunosupresor para modular la respuesta inmune, en un modelo experimental infectado con Paracoccidioides brasiliensis. Ratas machos Buffalo/Sim endocriadas de 250-300 gr. de peso, fueron inoculadas por via intracardiaca con 5.10 6 células de P. brasiliensis en fase levaduriforme. Un grupo de animales fue tratado con 20 mg/kg de peso de ciclofosfamida en los dias +4, +5, +6, +7, +11 y +12 p. i. mientras que un grupo control fue infectado solaménte. No se registró mortalidad en ninguno de los grupos. Las ratas tratadas presentaron: a) una disminución en el tamaño del granuloma, el cual contenia menor cantidad de células fúngicas; b) ausencia de anticuerpos específicos hasta los 35 dias p.i. y c) un aumento significativo en el test de hinchazón de la pata (DTH) contra la paracoccidioidina. Células esplénicas provenientes de dadores infectados con P. brasiliensis fueron transferidas a receptores infectados solamente, lo que produjo un aumento significativo de la DTH en estos últimos con respecto a los controles. Asi mismo, células esplénicas de dadores infectados solamente fueron transferidas a receptores infectados y tratados mostrando tambien un aumento en la DTH con respecto a los controles. Cada uno de los linfocitos T supresores pertenecientes a la cascada de células T parecerian ser sensibles a dosis sucesivas de ciclofosfamida hasta los 12 dias p.i.. Por otra parte, el esquema de tratamiento con ciclofosfamida podria inducir la aparición de una población de células T capaces de amplificar la respuesta DTH

A comparative study of antigenicity and patho-genicity for rats of six Paracoccidioides brasiliensis strains was carried out. The antigenic capacity "in vitro" of cytoplasmic extract from each strain was determined by immuno-diffusion test against 6 serum samples obtained from rats experimentally infected with Paracoccidioides brasiliensis, that had presented positive reactions with a metabolic control antigen. The cytoplasmic extracts were used at final concentration of 100 mg/ml. All of them showed 2 or 3 precipitation bands in this assay. One hundred twenty Wistar rats both sexes weighing approximately 200 g, were inoculated intracardiacally with suspensions of the yeast phase of different P. brasiliensis strains. Two concentrations containing 3x10(7) and 5x10(7) cells/ml of each isolate were prepared. The inoculated animals were divided in two groups, one was left to its spontaneous outcome and the percentages of deaths were registered and the other rats were sacrificed at 14, 28, 56 and 70 days post-infection. The following parameters were taken into account for evaluation: A) presence of macroscopic granulomas in lung, liver, spleen and kidney; B) presence of P. brasiliensis in microscopic exams of the same organs, in wet preparations and in hystologic sections stained by H&E; C) culture of lung and D) immunodiffusion test using pre-mortem serum samples and the homologous antigen. The correlation between the most important parameters studied in each strain are summarized as follow:As no significant differences between the two inocula employed for each strain was observed, the before-mention results are the average of those obtained with each inoculation doses. The most virulent strain was a recent isolate from an acute disseminated form of the juvenil type. A morphological atypic isolate, which produced a very mild experimental infection with viable P. brasiliensis determined 100% of positive immunodifussion tests. The strain 339 did not produce infection in the rats, and the animals inoculated did not presented antibodies. Nevertheless this strain is useful to prepare antigens for Serologic reactions. No correlation between antigenicity or pathogenicity and the time during which these strains were mantained "in vitro" could be established. Fueron estudiadas en forma comparativa 6 cepas de P. brasiliensis con el propósito de determinar su patogenicidad para la rata y su antigenicidad. Las mismas fueron aisladas de : 1) biopsia de cuello uterino en 1989 (U), 2) biopsia de mucosa bucal en 1988 (V), 3) aspiración ósea en 1991 (63265), 4) testículo de cobayo 1984(C24), 5) punción-aspiración ganglionaren 1986 (G) y 6) cepa proveniente de la Escola Paulista de Medicina (339). Se prepararon antigenos citoplasmáticos liofilizados de cada una de ellas, en la concentración final de 100 mg/ml y se realizaron pruebas de inmunodifusión frente a 6 sueros patrones positivos de ratas. En este ensayo todos los antígenos presentaron dos ó tres bandas de precipitación. Para estudiar el poder patógeno se inocularon, en total, 120 ratas Wistar, de ambos sexos de 200 g de peso, por via intracardíaca con suspensiones de la fase levaduriforme del P. brasiliensis, en concentraciones de 3x10(7) y 5x10(7) células/ml de cada cepa. Los animales que no murieron espontáneamente fueron sacrificados a los 14,28,42, 56 y 70 dias post-infección y se evaluaron los siguientes parámetros: A) exámenes macro y microscópicos de pulmones, hígado, bazo y riñones; B) cultivos de un pulmón y C) prueba de inmunodifusión con antígeno homólogo. Se consideró además, el porcentaje de muertes espontáneas por cada cepa. Los resultados de estos estudios fueron los siguientes:No se observó relación entre la patogenicidad y la antigenicidad. La cepa más virulenta correspondió a un aislamiento reciente a partir de una forma juvenil grave y la más antigénica fue una cepa, morfológicamente atípica, que no provocó lesiones macroscópicas ni microscópicas en los órganos de las ratas.

One hundred and seventeen patients suffering systemic mycosis and AIDS were studied during 5 years in the Muñiz Hospital of Buenos Aires City. Seventy four of them presented cryptococcosis, 39 histoplasmosis and 4 both mycoses. The following specimens were studied for the diagnosis: skin and mucous membrane scrapings, bone marrow aspirations, bronchial secretions, biopsies of different organs, cerebral spinal fluid and blood cultures. Sera were also collected for serologic tests. A total of 203 samples from patients with histoplasmosis were studied, 46.3% of them showed H. capsulatum in microscopic examinations or in cultures, skin scraping was the most sensitive diagnostic method (94.7% of positive results), followed by biopsies (80%) and bone marrow cultures (42.1%). Specific antibodies were detected in 45.4% of the patients with histoplasmosis, using 2 different antigens and 3 types of serologic reactions (complement fixation test, immunodiffusion and counterimmunoelectrophoresis). A total of 413 samples from patients with cryptococcosis were examined, 69% of them confirmed the diagnosis. The mycologic study of CSF was the most sensitive method of study, since it registered positive results in 89.5%, followed by blood cultures (61.2%), skin scrapings (42.9%), and urine cultures (41.7%). Polisaccharyde antigens from C. neoformans in organic fluids were detected in almost all the cases. The aim of this study is to compare all the suitable diagnostic methods which can be used in systemic mycosis associated with AIDS in order to find the most rapid way of diagnosis. Durante 5 años se estudiaron 117 pacientes con micosis sistémicas asociadas al SIDA: 74 criptococosis, 39 histoplasmosis y 4 con ambas enfermedades. Para el diagnóstico analizamos los siguientes materiales: escarificaciones de lesiones cutáneas o mucosas, aspirados de médula ósea, secreciones bronquiales, biopsias de diversos órganos, líquido cefalorraquídeo, hemocultivos y sueros para determinaciones serológicas. Fueron estudiadas en total 203 muestras de pacientes con histoplasmosis, el 46.3% de las mismas acusó la presencia de H. capsulatum. Las escarificaciones cutáneas exhibieron la mayor sensibilidad (94.7%), seguidas por las biopsias (80%) y los mielocultivos (42.1%). La demostración de anticuerpos circulantes por medio de 3 pruebas serológicas y con de 2 antígenos específicos dio resultados positivos en el 45.4% de los pacientes. Se estudiaron en total 413 especímenes de pacientes con criptococosis, la confirmación diagnóstica fue posible en el 69% de las muestras. El mayor rendimiento se obtuvo con el LCR (89.5%), le seguieron en sensibilidad los hemocultivos (61.2%), las escarificaciones cutáneas (42.9%) y los urocultivos (41.7%). La búsqueda de antígeno en los fluidos orgánicos fue positiva en casi todos los casos. La revisión que presentamos permitirá una búsqueda más racional y rápida de los métodos de diagnóstico en las micosis asociadas al SIDA.

Se realizó E.L.I.S.A. con exoantígeno de Coccidioides immitis para la detectión de anticuerpos, en 67 sueros humanos diluidos 1/1000, 1/2000, 1/4000 y 1/8000. De los 18 sueros de enfermos de coccidioidomicosis comprobada por examen directo, cultivo y/o histología, 5 fueron negativos, en otros 13 fueron positivos en una o varias diluciones. 3/26 sueros de personas sanas, coccidioidino positivas, fueron positivos en títulos de 1/1000 y el resto no tuvo anticuerpos detectables. No presentaron reacciones positivas ninguno de los sueros controles de personas sanas, pero sí lo hicieron 4/8 pacientes con otras micosis. Se concluye que E.L.I.S.A. es útil para la detección de mínimas cantidades de anticuerpos o en sueros que no pueden ser procesados por fijación de complemento. No es recomendable el uso de la técnica en forma aislada por al presencia de reacciones cruzadas. An E.L.I.S.A. test for antibody detection, with an exo-antigen of Coccidioides immitis was standardized in 67 humans sera diluited in 1/1000, 1/2000, 1/4000 and 1/8000. Eightheen sera from mycologically proved cases of coccidioidomycosis were studied: 5 were negative and 13 were positive in some dilutions. 3/26 sera of healthy persons who presented positive skin tests with coccidioidin were positive and the other 23 sera did not have positive reactions. None of the 15 sera of healthy human exhibited positive E.L.I.S.A. Serum samples of 8 patients suffering other deep mycosis were studied, 4 of them presented cross-reactions in E.L.I.S.A. tests. E.L.I.S.A. test seems to be a useful Serologic technique for antibody detection in anticomplementary serum samples or when a low concentration of antibodies should be detected. As it is very sensitive, cross-reactions with other mycoses are frequent, thus the use other more specific serologic technique together E.L.I.S.A. is recommended.