The "milky way" galaxy of HIV-related central nervous system immune reaction syndromes

The landscape of central nervous system HIV infection is rapidly changing, leading to the recognition of a new constellation of overlapping syndromes and to a better insight for the elder ones. Among these, progressive multifocal leukoencephalopathy (PML) still poses several diagnostic and therapeutic challenges; nevertheless, recent developments in understanding PML in patients with multiple sclerosis may have benefitted HIV-positive patients suffering from PML too. We describe a peculiar case of PML-immune reconstitution inflammatory syndrome (IRIS) presenting a punctate pattern with "milky way" appearance on magnetic resonance imaging. Despite the fact that brain imaging and histopathology remain the mainstays for extricating through the expanding galaxy of HIV-related central nervous system dysimmune syndromes and although punctate pattern has been already well acknowledged as a suggestive finding of PML among patients on natalizumab, this radiological presentation is still poorly recognised in AIDS-related PML cases, leading to possible life-threatening diagnostic delays. This is also the first report about intravenous immunoglobulin treatment in AIDS-related PML-IRIS; the favourable clinical and radiological outcome of our case and the preliminary administrations of intravenous immunoglobulins in natalizumab-associated PML-IRIS from literature support probable benefits also among HIV-positive patients.