ABSTRACT
The main goals of this study were to perform an anatomopathological evaluation of equine tissue naturally infected with Pythium insidiosus and to compare the reliability of Grocott methenamine silver nitrate (GMS) and the labeled streptavidin-biotin (LSAB) techniques for the diagnosis of pythiosis. Samples of cutaneous wounds suggestive of pythiosis obtained from 55 horses were histologically studied using hematoxylin-eosin and GMS stains, and LSAB. Twenty eight, out of 34 GMS-positive samples, were LSAB-positive for Pythiuminsidiosum. The six LSAB-negative samples were apparently cases of zygomicosis. The remaining samples were diagnosed as follow: granulation tissue with eosinophilic infiltration without necrotic areas (nine cases); granulation tissue with eosinophilic infiltration and necrotic areas (seven); habronemiasis (four); sarcoid (one). In conclusion, the LSAB method was more specific for the diagnosis of P. insidiosum when compared to GMS.
O trabalho teve como objetivo comparar a técnica de Grocott metanamina de prata (GMS) com o método imunoistoquímico de streptavidina-biotina marcada (LSAB) no diagnóstico da pitiose. Fragmentos de feridas cutâneas suspeitas de pitiose provenientes de 55 eqüinos foram processados pelas técnicas de hematoxilina/eosina, GMS e imunoperoxidase (LSAB). Trinta e quatro casos foram positivos pelo GMS, dos quais 28 apresentaram imunomarcação (LSAB) positiva para Pythium insidiosum. Os seis casos restantes apresentaram diagnóstico compatível de zigomicose. Foram diagnosticados como tecido de granulação com infiltração de eosinófilos sem áreas de necrose (nove casos), tecido de granulação com infiltrado de eosinófilos e presença de áreas de necrose (sete), habronemose (quatro) e sarcóide (um). Concluiu-se que a imunoperoxidase pelo método LSAB apresenta maior especificidade no diagnóstico de infecção pelo P. insidiosum do que pelo método GMS.
ABSTRACT
The main goals of this study were to perform an anatomopathological evaluation of equine tissue naturally infected with Pythium insidiosus and to compare the reliability of Grocott methenamine silver nitrate (GMS) and the labeled streptavidin-biotin (LSAB) techniques for the diagnosis of pythiosis. Samples of cutaneous wounds suggestive of pythiosis obtained from 55 horses were histologically studied using hematoxylin-eosin and GMS stains, and LSAB. Twenty eight, out of 34 GMS-positive samples, were LSAB-positive for Pythiuminsidiosum. The six LSAB-negative samples were apparently cases of zygomicosis. The remaining samples were diagnosed as follow: granulation tissue with eosinophilic infiltration without necrotic areas (nine cases); granulation tissue with eosinophilic infiltration and necrotic areas (seven); habronemiasis (four); sarcoid (one). In conclusion, the LSAB method was more specific for the diagnosis of P. insidiosum when compared to GMS.
O trabalho teve como objetivo comparar a técnica de Grocott metanamina de prata (GMS) com o método imunoistoquímico de streptavidina-biotina marcada (LSAB) no diagnóstico da pitiose. Fragmentos de feridas cutâneas suspeitas de pitiose provenientes de 55 eqüinos foram processados pelas técnicas de hematoxilina/eosina, GMS e imunoperoxidase (LSAB). Trinta e quatro casos foram positivos pelo GMS, dos quais 28 apresentaram imunomarcação (LSAB) positiva para Pythium insidiosum. Os seis casos restantes apresentaram diagnóstico compatível de zigomicose. Foram diagnosticados como tecido de granulação com infiltração de eosinófilos sem áreas de necrose (nove casos), tecido de granulação com infiltrado de eosinófilos e presença de áreas de necrose (sete), habronemose (quatro) e sarcóide (um). Concluiu-se que a imunoperoxidase pelo método LSAB apresenta maior especificidade no diagnóstico de infecção pelo P. insidiosum do que pelo método GMS.
ABSTRACT
The clinical and pathological findings of a case of renal amyloidosis in a nine-year-old male Shar-Pei dog were described. Clinically, there were signs of sporotrichosis and renal insufficiency, besides being positive to leishmaniasis and ehrlichiosis. On the day before death, the animal became apathetic, dehydrated and anuric. On gross examination, there were several whitish millimetric spots seen widespread in both renal cortices and consolidation of the left diaphragmatic pulmonary lobe. The most important microscopic finding was a deposition of amorphous acellular material on the glomerular tufts which stained positively by congo red stain. Other changes were multifocal suppurative nephritis, thickening of the Bowman capsule and chronic suppurative bronchopneumonia. The origin of the amyloidosis in this case could be hereditary, being similar to familiar amyloidosis described in Shar-Pei breed, or due to chronic suppurative inflammation and/or leishmaniasis.
O presente relato descreve os achados clínicos e anatomopatológicos de um caso de amiloidose renal em um cão macho de nove anos da raça Shar-Pei. O animal apresentava quadro clínico de esporotricose e de insuficiência renal e exames positivos para erlichiose e leishmaniose. No dia anterior ao óbito, o cão apresentou apatia, desidratação e anúria. À necropsia foram observados inúmeros pontos milimétricos esbranquiçados localizados no córtex renal e hepatização do lobo diafragmático esquerdo. O achado histológico mais importante foi deposição de material eosinofílico, amorfo e acelular localizado nos tufos glomerulares que se corou positivamente pelo vermelho congo (amilóide). Observaram-se nefrite supurada multifocal, espessamento da cápsula de Bowman e broncopneumonia supurada crônica, com fibrose intensa. A origem da amiloidose, no presente caso, poderia ser hereditária, assemelhando-se à amiloidose familiar descrita em cães da raça Shar-Pei, ou ser devida à inflamação supurada crônica e/ou leishmaniose.