Avaliação imunológica nas pregas vestibulares de pacientes autopsiados com a Síndrome da Imunodeficiência Adquirida / Immunological evaluation of vestibular folds in autopsies of patients with the Acquired Immunodeficiency Syndrome

Em pacientes com Síndrome da Imunodeficiência Adquirida há uma diminuição das células envolvidas na resposta imune, o que influencia na população celular dos folículos linfóides encontrados nas pregas vestibulares, favorecendo o aparecimento de infecções nas vias aéreas destes pacientes. Estas infecções são a principal causa de mortalidade e morbidade nestes pacientes. OBJETIVO: Caracterizar a população de células nos folículos linfóides localizados nas pregas vestibulares de adultos autopsiados com Síndrome da Imunodeficiência Adquirida, com e sem infecções respiratórias associadas. MATERIAIS E MÉTODOS: Foi realizado um estudo retrospectivo transversal em 64 laringes de adultos coletadas na rotina das autopsias. Para a imunohistoquímica foram utilizados os anticorpos: Anti-B cells, Anti-CD3, Anti-CD68 e Anti-follicular dendritic cells. RESULTADOS: 46 (71,87 por cento) dos pacientes estudados tinham diagnóstico de Síndrome da Imunodeficiência Adquirida. Nestes pacientes, a celularidade dos folículos linfóides foi estatisticamente menor em relação ao grupo controle em todos os fenótipos estudados. Nos pacientes imunodeprimidos com infecção respiratória associada, o número de células estava diminuído, sendo significante no caso dos linfócitos T (p=0,024). CONCLUSÃO: Em nosso estudo demonstramos que os folículos linfóides das pregas vestibulares são afetados pela infecção viral e representam com fidedignidade o estado imunológico de imunodepressão destes pacientes.

Immune response cells are decreased in patients with the Acquired Immunodeficiency Syndrome. This alters the cell population in vestibular fold lymphoid follicles, leading to respiratory infections in these patients. Such infections are the main cause of mortality and morbidity in these patients. AIM: to characterize lymphoid follicle cell populations in the vestibular folds of adults with the Acquired Immunodeficiency Syndrome and associated or not respiratory infection. MATERIALS AND METHODS: A retrospective study was made of 64 adult larynges harvested during routine autopsies. Anti-B cell, Anti-CD3, Anti-CD68 and Anti-follicular dendritic cell antibodies were used for immunological testing. RESULTS: 46 (71.87 percent) of the sample patients had the Acquired Immunodeficiency Syndrome. In these patients, lymphoid follicle cellularity was lower compared to the control group. The cell number was decreased in patients with the Acquired Immunodefficiency Syndrome and associated respiratory tract infection. CONCLUSION: We demonstrated in this study that vestibular fold lymphoid follicles were affected by viral infections, and may be considered as a reliable marker of immunodepression in these patients.

Follicular dendritic cell sarcoma of oral cavity: report of 2 cases.

We report 2 cases of Follicular Dendritic Cell Sarcomas of Oral Cavity in two elderly patients. The patients presented with oral cavity tumors. Initial tru-cut biopsies in both cases revealed spindle cell neoplasms. One of them was of low grade malignancy and showed positivity for of Vimentin. Few cells showed positivity for keratin and were negative for S-100 protein, CD 34, CD 68, EMA, SMA, HMB-45. A possible diagnosis of low grade fibrohistiocytic tumor was made. He underwent Lt total maxillectomy. Three years later he presented back with regional nodal metastasis. The regional lymph nodes showed features of follicular dendritic cell sarcoma. The second case revealed high grade spindle cell neoplasm and showed positivity for vimentin and S100 protein and was negative for EMA, keratin, CD-34, desmin, muscle actin and HMB-45. He was offered initial radio-therapy followed by hemifacial resection. The histology along with immuno histochemistry favoured a diagnosis of follicular dendritic cell sarcoma. He presented with local recurrence two months later. Both the cases are discussed in detail.

Follicular dendritic cell tumour of tonsil - is it an under-diagnosed entity?

Neoplasms of follicular dendritic cells are uncommon and while majority of them occur in lymph nodes, they are increasingly recognized at varied sites such as abdominal viscera. Tonsil is the most common extra nodal site for occurrence of FDCT in the head and neck region. We describe three cases of follicular dendritic cell tumour occurring in the tonsil.

Follicular dendritic cell tumor of mesentery--a case report.

Follicular dendritic cell sarcoma also known as dendritic reticulum cell tumor is uncommon. It can arise in lymph nodes and extra nodal sites namely tonsils and intra abdominal locations. The tumor morphologically mimicks soft tissue sarcomas and hence requires immunohistochemical study for correct diagnosis. It pursues an indolent protracted course with recurrence and still be compatible with long survival. We report a case of follicular dendritic cell tumor of mesentery.

Follicular dendritic cell tumour--a case report.

Follicular dendritic cell tumors are rare entities, which are however being increasingly recognised. One such tumor in the parapharyngeal region, diagnostically challenging, and with an unusual histological feature is reported, with a short review of the literature.

Los priones, un nuevo desafío evolutivo / Prions: a new evolutionary defiance

El objetivo de esta reseña es actualizar información ya publicada sobre los priones y las patologías que éstos transmiten. La existencia de una nueva variante de la enfermedad de Creutzfeld-Jakob y la confirmación experimental de que es causada por la misma cepa de priones que la encefalopatía espongiforme bovina (BSE), ha incrementado dramáticamente la necesidad de una precisa comprensión de las bases moleculares de la propagación priónica. El agente infeccioso es una proteína cuya conformación se encuentra alterada, que se reproduce a sí misma convirtiendo una proteína normal en una proteína con conformación priónica. La observación de que los priones se replican en los órganos linfoides en estadios muy tempranos de la infección lleva a cuestionar sobre cuáles son los requerimientos de tipo celular a ser infectado en el sistema linforreticular. Las células dendríticas foliculares serían el sitio de elección para la replicación y el reservorio de priores. El diagnóstico de las enfermedades producidas por priones presenta una serie de problemas debido a las peculiaridades de este tipo de patologías. Considerando que los priones se replican en el sistema linforreticular y posteriormente migran al sistema nervioso central, existe un lapso durante el cual podría propagarse este agente infeccioso por medio de la sangre, sus componentes o sus derivados. De esta forma representaría una nueva patología con la potencial capacidad de transmisión transfusional. Esta nueva forma de herencia independiente de los ácidos nucleicos obliga a replantear el axioma de transferencia de la información genética, hasta el momento, y con concordancia con la teoría evolutiva de Darwin, sólo pensando mediante moléculas constituidas por nucleótidos. ¿Será tiempo de cambiar el paradigma?

Mediastinal Castleman's disease complicated by follicular dendritic cell tumour.

We describe a rare case of follicular dendritic cell tumour which had arisen over the background of hyaline vascular type of Castleman's disease at the mediastinal location. Constellation of histology and immunohistochemistry using CD21 antibody and non-reactivity to CD15, CD30, cytokeratin and epithelial membrane antigen helped us diagnose this case. The literature is reviewed, specially with reference to the genesis of follicular dendritic cell neoplasm at the backdrop of Castleman's disease and its clinical relevance.

Clinicopathologic study of Castleman's disease in Korea

Castleman's disease represents an atypical lymphoproliferative disorder, infrequently associated with various immunologic abnormalities or subsequent development of malignancy such as Kaposi sarcoma, malignant lymphoma and plasmacytoma. Its clinicopathologic features depend on various etiologic factors such as Kaposi sarcoma herpesvirus (KSHV), oversecretion of IL-6, adhesion molecule and follicular dendritic cell dysplasia, etc. To investigate the relationship of Castleman's disease (CD) and the above factors, we reviewed 22 cases of CD. Four cases of KSHV positive CD were detected, all multicentric, plasma cell type, and these cases displayed prominent vascular proliferation, characteristic 'Kaposi-like lesion'. IL-6 and CD54 positive mononuclear cells were scattered in interfollicular areas of KSHV positive cases. Follicular dendritic cell hyperplasia, vascular proliferation, expression of IL-6 and CD54 did not show any significant difference between solitary vs multicentric type, and plasma cell type vs hyaline vascular type. Our study suggests that KSHV positive CD reveals unique pathologic features, and the probable relationship of KSHV and IL-6 and CD54 is discussed.