Human Polyomavirus-Associated Cerebral Disorders in the Post-HAART Era.

Human polyomavirus JC is the causative agent of a deadly form of sudden onset dementia, progressive multifocal leukocoencephalopathy (PML). PML is highly prevalent in immunodeficient populations, specially those undergoing chemotherapy, immunosuppressive treatments for autoimmune conditions, and HIV-1/AIDS patients. In fact, before the highly active antiretroviral therapy (HAART) regimens became available, PML was a leading cause of death in HIV-1 seropositive individuals. However, patients under HAART show increased survival times with better prognoses. In this report we described the main differences between PML before and after the HAART era; highlighting the new patterns of presentation, the neurotropism of other human polyomaviruses, and the increased prevalence of immune reconstitution inflammatory syndrome (IRIS), as a complication of PML in patients under HAART. Lastly, we propose a revised classification of human poliomavirus-associated cerebral disorders that may reflect more accurately what clinicians encounter in their everyday practice.

Inflammatory papillomatous hyperplasia and epidermal necrosis in a transgenic rat for HIV-1.

BACKGROUND: Skin lesions commonly affect AIDS patients. The pathogenesis of certain dermatologic disorders primarily associated to HIV-1 is unclear, and better forms of therapy for these conditions need to be discovered. Transgenic animal models represent a novel approach for the study of these disorders and for the quest of more effective forms of treatment. OBJECTIVE: Characterize this HIV-1 transgenic rat as a model to study skin diseases related to HIV/AIDS. METHODS: A transgenic rat was developed, using an HIV-1 construct with deleted gag and pol genes. Morphological and genotypical evaluations were followed by cytokine profile characterization of the lesions. RESULTS: We report the characterization of a colony of HIV-1 transgenic rats that developed skin lesions in a frequency of 22.5%. Cutaneous expression of functional HIV-1 transgenes correlated precisely with the severity of the phenotype. In early stages, rats manifested localized areas of xerosis and dispersed papulosquamous lesions. These hyperplastic manifestations were observed in conjunction with an increased epidermal expression of tat protein and a Th1/Th2 profile of cytokines. As the lesions progressed, they formed inflammatory plaques that subsequently ulcerated. Histologically, these lesions displayed a profound lymphocytic infiltrate, epidermal necrosis, and a marked increase of both Th1 and Th2 derived cytokines. Moreover, the presence of circulating IgG antibodies against HIV-1 gp120 was detected. CONCLUSION: This animal model as other HIV-1 transgenic mice described in the past, is not able to fully explain the myriad of skin findings that can occur in HIV-infected humans; however, it represents a potential animal model system for the study of immune-mediated inflammatory skin diseases.

Aids-related progressive multifocal leukoencephalopathy: a retrospective study in a referral center in São Paulo, Brazil.

Few data are available about progressive multifocal leukoencephalopathy (PML) in patients with acquired immunodeficiency syndrome (AIDS) from Brazil. The objectives of this study were to describe the main features of patients with PML and estimate its frequency among AIDS patients with central nervous system (CNS) opportunistic diseases admitted to the Instituto de Infectologia Emílio Ribas, São Paulo, Brazil, from April 2003 to April 2004. A retrospective and descriptive study was performed. Twelve (6%) cases of PML were identified among 219 patients with neurological diseases. The median age of patients with PML was 36 years and nine (75%) were men. Nine (75%) patients were not on antiretroviral therapy at admission. The most common clinical manifestations were: focal weakness (75%), speech disturbances (58%), visual disturbances (42%), cognitive dysfunction (42%), and impaired coordination (42%). The median CD4+ T-cell count was 45 cells/microL. Eight (67%) of 12 patients were laboratory-confirmed with PML and four (33%) were possible cases. Eleven (92%) presented classic PML and only one case had immune reconstitution inflammatory syndrome (IRIS)-related PML. In four (33%) patients, PML was the first AIDS-defining illness. During hospitalization, three patients (25%) died as a result of nosocomial pneumonia and nine (75%) were discharged to home. Cases of PML were only exceeded by cases of cerebral toxoplasmosis, cryptococcal meningoencephalitis, and CNS tuberculosis, the three more frequent neurologic opportunistic infections in Brazil. The results of this study suggest that PML is not an uncommon HIV-related neurologic disorder in a referral center in Brazil.

Aids-related progressive multifocal leukoencephalopathy: a retrospective study in a referral center in São Paulo, Brazil / Leucoencefalopatia multifocal progressiva em pacientes com aids: estudo retrospectivo em um centro de referência de São Paulo, Brasil

Few data are available about progressive multifocal leukoencephalopathy (PML) in patients with acquired immunodeficiency syndrome (AIDS) from Brazil. The objectives of this study were to describe the main features of patients with PML and estimate its frequency among AIDS patients with central nervous system (CNS) opportunistic diseases admitted to the Instituto de Infectologia Emílio Ribas, São Paulo, Brazil, from April 2003 to April 2004. A retrospective and descriptive study was performed. Twelve (6 percent) cases of PML were identified among 219 patients with neurological diseases. The median age of patients with PML was 36 years and nine (75 percent) were men. Nine (75 percent) patients were not on antiretroviral therapy at admission. The most common clinical manifestations were: focal weakness (75 percent), speech disturbances (58 percent), visual disturbances (42 percent), cognitive dysfunction (42 percent), and impaired coordination (42 percent). The median CD4+ T-cell count was 45 cells/µL. Eight (67 percent) of 12 patients were laboratory-confirmed with PML and four (33 percent) were possible cases. Eleven (92 percent) presented classic PML and only one case had immune reconstitution inflammatory syndrome (IRIS)-related PML. In four (33 percent) patients, PML was the first AIDS-defining illness. During hospitalization, three patients (25 percent) died as a result of nosocomial pneumonia and nine (75 percent) were discharged to home. Cases of PML were only exceeded by cases of cerebral toxoplasmosis, cryptococcal meningoencephalitis, and CNS tuberculosis, the three more frequent neurologic opportunistic infections in Brazil. The results of this study suggest that PML is not an uncommon HIV-related neurologic disorder in a referral center in Brazil.

Existe informação limitada sobre a presença da leucoencefalopatia multifocal progressiva (LEMP) em pacientes com aids no Brasil. Os objetivos do presente estudo foram descrever as principais características dos pacientes com LEMP e estimar a freqüência desta doença em pacientes com aids e doenças oportunistas do sistema nervoso central (SNC) internados em um centro de referência de São Paulo, Brasil. Neste estudo retrospectivo e descritivo, identificamos 12 (6 por cento) casos de LEMP entre 219 pacientes com doenças neurológicas oportunistas do SNC. A idade média dos pacientes com LEMP foi 36 anos e 9 (75 por cento) eram do sexo masculino. As manifestações clínicas mais freqüentes foram: déficits focais (75 por cento), alterações da fala (58 por cento), alterações visuais (42 por cento), alterações cognitivas (42 por cento), e problemas de coordenação (42 por cento). A média da contagem de células T-CD4+ foi 45 células/µL. Oito (67 por cento) dos 12 pacientes com LEMP tiveram diagnóstico confirmado laboratorialmente e em quatro (33 por cento) casos o diagnóstico foi possível. Onze (92 por cento) pacientes apresentaram LEMP clássica e um caso teve LEMP associada à síndrome de reconstituição imune. Em quatro (33 por cento) pacientes, a LEMP foi a primeira doença definidora de aids. Durante a internação, três pacientes (25 por cento) faleceram devido a pneumonia hospitalar e nove (75 por cento) tiveram alta. A LEMP foi apenas ultrapassada em freqüência pela toxoplasmose cerebral, a meningoencefalite criptococócica e a neurotuberculose, as três mais freqüentes doenças neurológicas oportunistas no Brasil. Os resultados deste estudo sugerem que a LEMP não é uma complicação neurológica incomum em pacientes com infecção pelo HIV no nosso meio.

BK virus associated meningoencephalitis in an AIDS patient treated with HAART.

A severely immune-suppressed AIDS patient was suspected of suffering from BK virus (BKV) meningoencephalitis, after being studied for common causes of neurological complications of co-infectious origin. Polymerase chain reaction (PCR) and sequence analysis of cerebrospinal fluid and brain samples, confirmed the presence of BKV. His clinical condition improved along with the regression of brain lesions, after modifications on his antiretroviral regime. Five months after discharge, the patient was readmitted because of frequent headaches, and a marked inflammatory reaction was evidenced by a new magnetic resonance imaging (MRI). The symptoms paralleled a rising CD4+ lymphocyte count, and immune reconstitution syndrome was suspected. This is the first non-postmortem report of BKV meningoencephalitis in an AIDS patient, showing clinical and radiographic improvement solely under HAART.

Noninfectious entry of HIV-1 into peripheral and brain macrophages mediated by the mannose receptor.

Although protein receptors on the plasma membrane involved in the initial steps of productive HIV-1 infection have been well characterized, little is known about interactions between cellular carbohydrate receptors and HIV-1. Here, we report the involvement of a carbohydrate receptor, the macrophage mannose receptor (MR), and its role in supporting HIV-1 binding and entry. HIV-1 can enter the cytoplasm of human macrophages and microglia as well as murine macrophages by MR, although no subsequent viral replication was observed. Correspondingly, HIV-1 entry into Cos-7 cells after induction of expression of MR by transfection with MR-cDNA did not demonstrate viral replication. Our studies suggest that whereas MR may serve as a binding and an entry site, the MR-mediated pathway does not lead to productive HIV-1 infection. In addition, we report that recombinant HIV-1 gp120 blocks MR-mediated phagocytosis in human and murine alveolar macrophages and microglial cells. Therefore, characterization of the HIV-1 noninfectious MR-mediated phagocytic pathway may foster advances in HIV-1 vaccine design and an improved understanding of HIV-1/AIDS pathogenesis and host defenses.

International NeuroAIDS: prospects of HIV-1 associated neurological complications.

Neurological complications associated with HIV-1/AIDS are being recognized with a high frequency that parallels the increased number of AIDS cases. The early infiltration by HIV-1 into the nervous system can cause primary and/or secondary neurological complications. The most common neurocognitive disorder is AIDS Dementia Complex (ADC). In developing countries of Asia the three most opportunistic infections are tuberculosis (TB), cryptococcosis, and Pneumocystis carinii pneumonia. Therefore, it is expected that secondary neurological complications due to TB and cryptococcosis will be the most common cause of morbility and mortality in HIV-1/AIDS cases in China. Research of NeuroAIDS in China is necessary to understand the impact and the biology of HIV-1 in the nervous system. Future studies would include, the molecular epidemiology and the description of opportunistic infections associated to HIV-1; the neuropathological description of primary and secondary HIV-1 complications in different groups; the HIV-1 neurotropism and immune response studies for China's unique HIV-1 strains and recombinant forms derived from the nervous system, including experimental models such as the use of transgenic rats; and the study of potential resistant virus, primarily when the anti-retroviral therapy (ART) has not full access in the brain.