Progressive multifocal leukoencephalopathy in a HIV/HTLV co-infected patient

Post-cART progressive multifocal leukoencephalopathy era in a Brazilian center

Progressive multifocal leukoencephalopathy (PML) is lytic infection of oligodendrocytes caused by JC virus (JCV). While PML incidence in developing countries has decreased after the introduction of combination antiretroviral therapy (cART), data in developing countries is scarce and limited to few cohorts. We described the epidemiological and clinical profile of a group of Brazilian HIV infected patients with PML in the cART era. A total of 27 patients were included in the study. The median age at PML onset was 42years (range: 27-67years) and 18 (66.7%) were men. The median CD4+ T cell count at the time of diagnosis was 67cells/mm³ and the median HIV viral load was 27,000copies/ml. Motor deficits were the most common early manifestations (44%). Seizures occurred in 37% of the patients and 9 (33.3%) had PML associated with immune reconstitution inflammatory syndrome (IRIS). Mortality was 33% and lower age at PML onset was associated with survival (p: 0.013). Our results are in accordance with previous published series of PML cases. Factors such as genetic background, regional JCV subtype differences, death from other diseases and underdiagnosis may explain the low prevalence of reported PML cases in developing countries.

[A case of progressive multifocal leukoencephalopathy with Takayasu arteritis and indolent adult T-cell lymphoma/leukemia]

A 65-year-old man with Takayasu arteritis in a stable condition was admitted to our hospital because of rapid progressive dementia. Brain FLAIR/T2-weighted magnetic resonance images revealed high signal intensity in the diffuse subcortical white matter. John Cunningham virus (JCV) genome in cerebrospinal fluid was detected by polymerase chain reaction. Finally, progressive multifocal leukoencephalopathy was diagnosed definitely by brain biopsy. In addition, the patient was found to be complicated by chronic/smoldering adult T-cell leukemia/lymphoma. The administration of mefloquine with mirtazapine was early started within two months after the onset. However, the combination treatment led to no improvement in symptoms and lesion size. The patient died six months after the onset. Therefore, this case suggested that both of HTLV-I infection and B cell abnormalities due to Takasasu arteritis impaired the therapeutic effect.

The Role of Virus Infection in Deregulating the Cytokine Response to Secondary Bacterial Infection

Proinflammatory cytokines are produced by macrophages and dendritic cells (DCs) after infection to stimulate T helper (Th) cells, linking innate and adaptive immunity. Virus infections can deregulate the proinflammatory cytokine response like tumor necrosis factor-α and interleukin (IL)-2, making the host more susceptible to secondary bacterial infections. Studies using various viruses such as lymphocytic choriomeningitis virus, influenza A virus, and human immunodeficiency virus have revealed several intriguing mechanisms that account for the increased susceptibility to several prevalent bacterial infections. In particular, type I interferons induced during a virus infection have been observed to play a role in suppressing the production of some key antibacterial proinflammatory cytokines such as IL-23 and IL-17. Other suppressive mechanisms as a result of cytokine deregulation by viral infections include reduced function of immune cells such as DC, macrophage, natural killer, CD4(+), and CD8(+) T cells leading to impaired clearance of secondary bacterial infections. In this study, we highlight some of the immune mechanisms that become deregulated by viral infections, and can thus become defective during secondary bacterial infections.