Aspectos clínicos, parasitológicos e histopatológicos decorrentes da morte de vermes adultos de Wuchereria bancrofti em linfáticos intra-escrotai
Data
2000
Autores
Norões, Joaquim Alfredo Alves 
Orientadores
Cedenho, Agnaldo Pereira
Tipo
Tese de doutorado
Título da Revista
ISSN da Revista
Título de Volume
Resumo
A hidrocele é a manifestação clínica mais comum da filariose bancroftiana. Entretanto, o mecanismo de formação das suas formas aguda e crônica é ainda pouco compreendido, tanto nos indivíduos tratados quanto naqueles que não receberam tratamento antifilarial. Estudo prospectivo de 192 pacientes do sexo masculino infectados pela Wuchereria bancrofti indicou que a formação de nódulos em linfáticos intra-escrotais decorrente da morte do estádio adulto do parasito é a causa mais frequente na indução de hidroceles em área endêmica de bancroftose. Mostrou, também, que os pacientes que formaram nódulo em área paratesticular tinham um risco de 63% de desenvolverem hidrocele. Nos 18 meses de estudo a incidência de hidrocele aguda foi de 20,8% (40/192 pacientes) e foi significativamente maior naqueles indivíduos que tiveram os seus vermes mortos pela ação da dietilcarbamazina (DEC). Houve regressão espontânea das hidroceles agudas em 79,5% dos pacientes e essa involução se fez em, até, sete meses após a sua formação. De 189 pacientes (3 foram excluídos por terem tido ressecada a tunica vaginal após realização de biópsia de nódulo), 9 (4,8%) portadores de hidrocele aguda, evoluíram para a fase crônica da doença. Ao contrário da forma aguda, a incidência de hidrocele crônica não foi diferente entre aqueles que receberam e os que não receberam tratamento. O granuloma filarial formado teve o mesmo padrão histológico independente de o verme adulto ter sido morto ou ter morrido naturalmente. Com a resolução da sua fase inflamatória, ocorreu a recanalização do vaso linfático, o que explica a involução da maioria das hidroceles agudas desenvolvidas em decorrência da obstrução abrupta do linfático pelo nódulo filarial. Através dos achados clínicos e cirúrgicos observou-se que o granuloma representa, na verdade, uma linfangite aguda localizada e foi detectado, exclusivamente, nos linfáticos de drenagem do conteúdo escrotal que é o sítio de predileção dos vermes adultos na população estudada. Nessa localização os nódulos podem passar totalmente desapercebidos pelos pacientes, a menos que se faça um exame físico criterioso do conteúdo escrotal. Esse estudo fortalece o suporte dos programas de controle que objetivam a implatação do tratamento em massa das comunidades endêmicas utilizando a DEC. Nesse estudo essa droga não induziu o aumento da morbidade crônica da infecção na população masculina.
In the male population, hydrocele is the most common clinical manifestation of bancroftian filariasis. The underlying mechanisms that cause hydrocele are unknown, both for patients treated with antifilarial drugs and those who are not treated. A prospective study of 192 male patients infected with Wuchereria bancrofti showed that formation of nodules in the intrascrotal lymphatics secondary to adult worm death is the most frequent cause of hydrocele in bancroftian-endemic areas. Patients who developed nodules in the paratesticular area had a 63% risk of developing hydrocele. Within 18 months of follow-up, the overall incidence of acute hydrocele was 20.8% (40/192 patients); this figure was statistically significantly higher in patients treated with diethycarbamazine (DEC). Spontaneous regression of acute hydrocele occurred in 79.5% of patients, and up to 7 months after onset. Of 189 patients (3 were excluded because the tunica vaginalis was excised when nodule was biopsed), 9 (4.8%) had acute hydrocele that progressed to a chronic stage, whether or not they were treated with antifilarial drugs. The histologic pattern of the filarial granuloma at the site of the nodule was similar regardless of whether the adult worm death was “natural” or provoked by DEC. After the resolution of the inflammatory phase, recanalization of the lymphatic vessel occurs, which explains the involution of acute hydrocele in the majority of cases produced by acute obstruction of the lymphatic lumen by the filarial nodule. The filarial granuloma represents a localized phenomenon, a true acute lymphangitis occurring in the lymphatics that drain the intrascrotal contents, the preferential site of W. bancrofti adult worms in the studied population. Nodule formation was not noticed by 50% of patients, unless a careful physical examination of the intrascrotal contents was performed. This study supports the rationale for control programs using mass treatment with DEC in endemic communities. The adulticidal effect of DEC did not induce more chronic morbidity than did natural death of the adult worm.
In the male population, hydrocele is the most common clinical manifestation of bancroftian filariasis. The underlying mechanisms that cause hydrocele are unknown, both for patients treated with antifilarial drugs and those who are not treated. A prospective study of 192 male patients infected with Wuchereria bancrofti showed that formation of nodules in the intrascrotal lymphatics secondary to adult worm death is the most frequent cause of hydrocele in bancroftian-endemic areas. Patients who developed nodules in the paratesticular area had a 63% risk of developing hydrocele. Within 18 months of follow-up, the overall incidence of acute hydrocele was 20.8% (40/192 patients); this figure was statistically significantly higher in patients treated with diethycarbamazine (DEC). Spontaneous regression of acute hydrocele occurred in 79.5% of patients, and up to 7 months after onset. Of 189 patients (3 were excluded because the tunica vaginalis was excised when nodule was biopsed), 9 (4.8%) had acute hydrocele that progressed to a chronic stage, whether or not they were treated with antifilarial drugs. The histologic pattern of the filarial granuloma at the site of the nodule was similar regardless of whether the adult worm death was “natural” or provoked by DEC. After the resolution of the inflammatory phase, recanalization of the lymphatic vessel occurs, which explains the involution of acute hydrocele in the majority of cases produced by acute obstruction of the lymphatic lumen by the filarial nodule. The filarial granuloma represents a localized phenomenon, a true acute lymphangitis occurring in the lymphatics that drain the intrascrotal contents, the preferential site of W. bancrofti adult worms in the studied population. Nodule formation was not noticed by 50% of patients, unless a careful physical examination of the intrascrotal contents was performed. This study supports the rationale for control programs using mass treatment with DEC in endemic communities. The adulticidal effect of DEC did not induce more chronic morbidity than did natural death of the adult worm.
Descrição
Citação
NORÕES, Joaquim Alfredo Alves. Aspectos clínicos, parasitológicos e histopatológicos decorrentes da morte de vermes adultos de Wuchereria bancrofti em linfáticos intra-escrotai. Tese (Doutorado em Ciências) - Escola Paulista de Medicina, Universidade Federal de São Paulo (UNIFESP), São Paulo, 2000.