Paracoccidioidomycosis: no genetic damage in human peripheral blood cells of patients assessed by single-cell gel (comet) assay

Paracoccidioidomycosis is a systemic fungal infection caused by Paracoccidioides brasiliensis. As infectious diseases can cause DNA damage, the authors aimed at analyzing DNA breakage in peripheral blood cells of patients with paracoccidioidomycosis by using the comet assay. The results suggested that paracoccidioidomycosis does not cause genotoxicity.

Paracoccidioidomicose é micose sistêmica causada pelo Paracoccidioides brasiliensis. Considerando que doenças infecciosas são capazes de induzir danos genéticos, o objetivou-se analisar quebras no DNA em células de sangue periférico de pacientes com paracoccidioidomicose utilizando o teste do cometa. Os resultados sugeriram que essa enfermidade não exerce genotoxicidade.

Cytokines produced by suscesptible and resistant mice in the course of Paracoccidioides brasiliensis infection

Paracoccidioidomycosis (PCM) is the most prevalent deep mycosis in Latin America and presents a wide spectrum of clinical manifestations. We established a genetically controlled murine model of PCM, where A/Sn mice develop an infection which mimics the benign disease (immune responses which favor cellular immunity) and B10.A animals present the progressive disseminated form of PCM (preferential activation of B cells and impairment of cellular immune responses). To understand the immunoregulatory phenomena associated with resistance and susceptibility in experimental PCM, A/Sn and B10.A mice were studied regarding antigen-elicited secretion of monokines (TNF-alpha and TGF-beta) and type-1 (IL-2 and IFN-gamma) and type-2 (IL-4,5,10) cytokines. Total lymph node cells from resistant mice infected ip with P. brasiliensis produced early and sustained levels of IFN-gamma and IL-2; type-2 cytokines (IL-4 and IL-05) started to appear 8 weeks after infection. In contrast, susceptible mice produced low levels of IFN-gamma concomitant with significant levels of IL-5 and IL-10 early in the infection. In the chronic phase of the disease, susceptible animals presented a transitory secretion of IL-2, and IL-4. In the pulmonary infection IL-4, IL-5 and IL-10 were preferentially detected in the lung cells washings of susceptible animals. After in vitro challenge with fungal antigens, normal peritoneal macrophages from B10.A mice secreted high levels of TGF-beta and low levels of TNF-alpha. In contrast, macrophages from A/Sn animals released high levels of TNF-alpha associated with a small production of TGF-beta. The in vivo depletion of IFN-gamma not only abrogated the resistance of A/Sn mice but also diminished the relative resistance of B10.B animals. The in vivo depletion of IL-4 did not alter the disease outcome, whereas administration of rIL-12 significantly enhanced resistance in susceptible animals. Taken together, these results suggest that an early secretion of high levels of TNF-alpha and IFN-gamma followed by a sustained secretion of IL-2 and IFN-gamma plays a dominant role in the resistance mechanisms to P. brasiliensis infection. In contrast, an early and ephemeral secretion of low levels of TNF-alpha and IFN-gamma associated with production of IL-5 IL-10 and TGF-beta characterizes the progressive disease of susceptible animals.

Seguimiento post-terapia en pacientes con paracoccidioidomicosis tratados con itraconazol

De 80 pacientes con paracoccidioidomicosis (PCM) que, a partir de 1985, fueran diagnosticados en los laboratorios de la Corporación para Investigaciones Biológicas (CIB) y que recibieran tratamiento con itraconazol (ITZ), fue posible hacer un seguimiento post-terapia prolongado (promedio de 30 meses, rango 1-8 años) en 53 de ellos. Al momento del diagnóstico, 50 presentaban la forma crónica pulmonar del adulto y los 3 restantes, la forma juvenil. Cuatro de los enfermos estudiados habían recaído después de tratamiento con Ketoconazol. La mayoría de los pacientes (92.4 por ciento) recibieron 100 mgs diarios de ITZ, con una duración promedio de 6 meses de tratamiento en el 62 por ciento de los casos. Ninguno de los pacientes seguidos post-terapia presentó recaída durante el período de observación. Los sítomas más importantes a la terminación de la terapia fueron tos, expertoración y disnea, presentes al final de la terapia en 38.3 por ciento, 22.6 por ciento y 26.4 por ciento de los casos, respectivamente. Su frecuencia, sin embargo, disminuyó durante la observación post-terapia, persistiendo sólo la disnea en 35 por ciento de los casos. El seguimiento radiológico permitió observar la desaparición de los infiltrados retículo-nodulares presentes durante la terapia; sin embargo, la fibrosis fue permanente en 7 de los 11 pacientes que fueron seguidos por más de 4 años. En el 85 por ciento de los pacientes se notó un importante descenso en los títulos de anticuerpos contra el agente causal, P brasiliensis. Los anteriores hallazgos revelan la eficacia del ITZ en el tratamiento de la PCM; se comprueba que este triazol es superior a las drogas para administración oral o intravenosa anteriormente utilizadas ya que no se acompaña de recaídas.

Fibrosis patterns of lesions developed by athymic and euthymic mice infected with Paracoccidioides brasiliensis

Athymic and euthymic mice with BALB/c background were used to study the patterns of fibrosis during ip infection with a virulent isolate of Paracoccidioides brasiliensis. Specimens from various organs were collected from the animals at 1,4 and 7 weeks after infection and observed under light microscopy using various histologic staining methods. Lesions from the first week of infection, in both animal groups, presented a predominance of collagen III over I, carboxylated proteoglycans, and a tendency to encapsulation. From 4 weeks onward, the lesions of nu/+mice tended to involute to macrophage-pseudoxanthomatous aggregates or to encapsulation with an increase of collagen I and sulfated proteoglycans. On the contrary, with the evolution of the infection, the nu/nu mice displayed permanently active lesions, rich in reticular fibers and carboxylated proteoglycans, with varied amounts of collagens III and I, without or with minimal encapsulation. However, independent of the type of mice, or of the type of lesions, the minimal P. brasiliensis-ECM unit was formed by a fibrillar cocoon of reticular fibers that encloses an individual yeast or a "family" composed of a mother cell plus one or various peripheral daughter cells, alone or engulfed by macrophages or giant cells. The overal difference of the lesions of nude and normal mice was not in isolated aspects of their components, but in the general architecture of the lesions. Those of nu/+mice were either of involutive or of encapsulated type (slightly active), and those of nu/nu mice were of the sustained-expansive type (very active), without or with minimal encapsulation

Isoniazid acetylating phenotype in patients with paracoccidioidomycosis and its relationship with serum sulfadoxin levels, glucose-6-phosphate dehydrogenase and glutathione reductase activities

Os autores avaliaram o fenótipo acetilador da isoniazida, hematócrito, hemoglobina, atividade da glicose-6-fosfato desidrogenase, glutationa redutase e os níveis séricos de sulfadoxina de 39 doentes com paracoccidioidomicose, sendo 33 do sexo masculino e 6 do feminino, com idades compreendidas entre 17 e 58 anos. Vinte e um (53,84 por cento) doentes apresentaram fenótipo acetilador lento e 18(46,16 por cento) rápido. A atividade da glicose-6-fosfato desidrogenase (G6PD) esteve diminuída em 5(23,80 por cento) acetiladores lentos e 4(22,22 por cento) rápidos. A atividade da glutationa redutase esteve diminuida em 14 (66,66 por cento) acetiladores lentos e 12 (66,66 por cento) rápidos. Os níveis séricos de sulfadoxina livre e total foram maiores nos acetiladores lentos (p < 0,02). A análise dos resultados permite concluir que os níveis séricos de sulfadoxina relaciona-se com o fenótipo acetilador. Além disso, os níveis estiveram sempre acima de 50µg/ml, níveis estes considerados terapêuticos. Por outro lado, a deficiência de glutationa redutase pode estar relacionada com a má absorçäo intestinal de nutrientes, entre eles riboflavina, vitamina precursora de FAD