HIV-associated progressive multifocal leukoencephalopathy: longitudinal study of JC virus non-coding control region rearrangements and host immunity

John Cunningham virus (JCV), the etiological agent of progressive multifocal leukoencephalopathy (PML), contains a hyper-variable non-coding control region usually detected in urine of healthy individuals as archetype form and in the brain and cerebrospinal fluid (CSF) of PML patients as rearranged form. We report a case of HIV-related PML with clinical, immunological and virological data longitudinally collected. On admission (t0), after 8-week treatment with a rescue highly active antiretroviral therapy (HAART), the patient showed a CSF-JCV load of 16,732 gEq/ml, undetectable HIV-RNA and an increase of CD4+ cell count. Brain magnetic resonance imaging (MRI) showed PML-compatible lesions without contrast enhancement. We considered PML-immune reconstitution inflammatory syndrome as plausible because of the sudden onset of neurological symptoms after the effective HAART. An experimental JCV treatment with mefloquine and mirtazapine was added to steroid boli. Two weeks later (t1), motor function worsened and MRI showed expanded lesions with cytotoxic oedema. CSF JCV-DNA increased (26,263 gEq/ml) and JCV viremia was detected. After 4 weeks (t2), JCV was detected only in CSF (37,719 gEq/ml), and 8 weeks after admission (t3), JC viral load decreased in CSF and JCV viremia reappeared. The patient showed high level of immune activation both in peripheral blood and CSF. He died 4 weeks later. Considering disease progression, combined therapy failure and immune hyper-activation, we finally classified the case as classical PML. The archetype variant found in CSF at t0/t3 and a rearranged sequence detected at t1/t2 suggest that PML can develop from an archetype virus and that the appearance of rearranged genotypes contribute to faster disease progression

Drug-Induced Progressive Multifocal Leukoencephalopathy: A Comprehensive Analysis of the WHO Adverse Drug Reaction Database

Objective To identify safety signals concerning the association between the use of various drug classes and the onset of progressive multifocal leukoencephalopathy (PML). Methods All reports containing suspected or interacting PML-related or leukoencephalopathy-related drugs, held in the World Health Organization spontaneous individual case safety reports database as at 1 September 2014, were retrieved.Weidentified safety signals by analysing the drug– reaction pairs, using the reporting odds ratio as a measure of disproportionality. A safety signal was defined if a drug was reported more than twice in PML cases with a reporting odds ratio[2 and a lower 95 % confidence limit[1. Results We retrieved 2452 reports associated with PML (N = 1612), leukoencephalopathy (N = 835) or both (N = 5), corresponding to 343 different drugs. PML was reported similarly in male and female adults (18–64 years), and almost 30 % of the cases had a fatal outcome. The most frequent Anatomical Therapeutic Chemical (ATC) classification groups concerned antineoplastic agents (23.5 %), antivirals for systemic use (10.1 %) or immunostimulants (4.6 %). Significant disproportionality was found for 88 drugs in the overall analysis (of cases with ‘progressive multifocal leukoencephalopathy’ or ‘leukoencephalopathy’ as the Preferred Term), and a new safety signal was identified for 59 active substances (e.g. muromonab-CD3, basiliximab and antithymocyte Ig), as no information on a possible risk of PML was acknowledged in their Summary of Product Characteristics documents. Some safety signals were confirmed also after sensitivity analysis adjustment for several confounding factors (underlying diseases and considering only ‘progressive multifocal leukoencephalopathy’ as the Preferred Term). Conclusion We report a possible association between several drugs and PML that has not been previously described. In addition, we have confirmed previously reported signals in a number of drugs. We highlight the need for follow-up by regulatory agencies

JC virus detection and JC virus-specific immunity in natalizumab-treated Multiple Sclerosis patients

<p>Abstract</p> <p>Background</p> <p>The use of natalizumab in multiple sclerosis (MS) may favour JC virus reactivation; this phenomenon is usually asymptomatic but can, albeit rarely, evolve into frank progressive multifocal leucoencephalopathy (PML).</p> <p>Methods</p> <p>JCV-specific CD8+ T lymphocytes were evaluated by flow cytometry over a 24-month period in 24 natalizumab-treated MS patients in whom JCV DNA was or was not detected in blood using quantitative real-time polymerase chain reaction; all these cases were asymptomatic.</p> <p>Results</p> <p>Perforin- and grazymes-containing VP-1-specific CD8+ T lymphocytes were reduced whereas CD107a-expressing cells were increased in JCV positive patients, suggesting an active degranulation of these cells; naïve CD8+ T lymphocytes were also decreased whereas memory cells were increased in patients in whom JCV reactivation was observed.</p> <p>Conclusion</p> <p>The presence of a CD8+ T lymphocyte-mediated effector immune response offers a greater insight into reactivation of JCV and its clinical sequelae, and may help the monitoring of patients on natalizumab therapy.</p