Human polyomavirus JC replication and non-coding control region analysis in multiple sclerosis patients under natalizumab treatment

Abstract

In the last years, the treatment of multiple sclerosis (MS) patients with natalizumab has been associated with the occurrence of progressive multifocal leukoencephalopathy (PML) caused by human polyomavirus JC (JCV). Here, we have shown a significant correlation between patients with JC viruria and positive JC-specific antibody response and patients without JCV-specific antibodies after 1 year of natalizumab (p = 0.0006). Furthermore, JCV-specific quantitative PCR on urine and plasma samples, collected at the enrollment (t0) and every 4 months (t1, t2, t3) in the first year and at two time points (t4 and t5) in the second year of natalizumab treatment, indicated the prevalence of JC viremia rather than JC viruria only in the second year of treatment (p = 0.04). Moreover, the analysis of JCV non-coding control region (NCCR) sequences in peripheral blood mononuclear cells of patients with JC-specific antibodies after 12 natalizumab infusions (t3) revealed the presence of rearranged sequences, whereas the prevalence of genotypes 1A, 1B, and 4 was detected in these patients by VP1 sequence analysis. In summary, JC viruria evaluation seems to be useful to identify early those patients who do not already develop a humoral immune response against JCV. It may also be interesting to study the JCV NCCR rearrangements since they could give us new insights on the onset of neuro-invasive viral variants.

Which is the best PML risk stratification strategy in natalizumab-treated patients affected by multiple sclerosis?

“…In this framework, since it is possible to speculate that the higher the JC viremia, the higher the possibility that the pathogenic JCPyV emerges, consider Q-PCR data and consequently analyze NCCR sequence could be useful to identify variants correlated with PML. Sequence analysis exhibited an archetype-like structural organization in all analyzed samples during the follow-up less than 12 months, although point mutations, previously observed by other authors in vivo and in vitro (Pietropaolo et al, 2015;Prezioso et al, 2017Prezioso et al, , 2018, were identified in plasma of 3 T0-T3 STRATIFY JV Ⓡ -negative patients and in plasma and PBMC of 1 T0-T3 STRATIFY JV Ⓡ -positive patient.…”

“…This result could be explained assuming that, the decrease of immunosurveillance at the urinary level, caused by natalizumab, determines, firstly, a higher JCPyV replication in renal cells with a viral shedding and, as expected from JCPyV biology, a subsequent release of JCPyV-infected cells into bloodstream (Chen et al, 2009). Moreover, reduced immunosurveillance determined an increment in JC viral load, from T0 to T5, which followed a linear trend with natalizumab infusions' number (Pietropaolo et al, 2015). To further corroborate that viral DNA detection could be considered a valid JCPyV alert, a contextual analysis of anti-JCPyV antibodies versus JC viral load, was carried out at T0 and at T3.…”

“…Three factors stratify risk: natalizumab therapy > 2 years, an antibodies index for JCPyV > 1,5 and previous immunosuppressive therapy (Wingerchuk and Weinshenker, 2016). Actually, anti-JCPyV antibodies index is the only parameter for PML risk stratification, although many others candidates, such as L-selectin (CD62L) expression, T-cell response to JCPyV reactivation in PML, microRNAs expression during natalizumab therapy (Wingerchuk and Weinshenker, 2016) and JCPyV-DNA detection in blood (viremia) have been proposed (Mancuso et al, 2012;Pietropaolo et al, 2015). Since the risk of PML is the main limitation to natalizumab administration, highly effective in reducing annualized relapse rate (ARR) of 55% (Polman et al, 2006), establishing risk against expected benefits represents an obligatory requirement of MS treatment algorithm.…”

Efficient propagation of archetype JC polyomavirus in COS-7 cells: evaluation of rearrangements within the NCCR structural organization after transfection

“…For the first time, these point mutations were detected in an NCCR structure derived from an in vitro replication. They were previously reported in urine of immunocompetent individuals [ 41 ] and in urine and PBMCs of multiple sclerosis patients undergoing natalizumab treatment [ 42 ]. It should be noted that the 37T-to-G nucleotide transversion in box B is located within the binding site for the cellular transcription factor Spi-B, which can play a crucial role in viral replication and neurovirulence.…”

Diagnostic assays for polyomavirus JC and progressive multifocal leukoencephalopathy

“…In a longitudinal study, Delbue et al found that 61.9% shedding JCV did so persistently . An increase in JC viruria has been reported in natalizumab‐treated MS patients without PML , and JC viruria evaluation may be a useful way for early identification of those JCV‐infected patients who have not already developed a humoral immune response to JCV . Similarly, Berger et al found that 37% of JCV seronegative patients receiving natalizumab in a single‐center, retrospective cohort study had JCV viruria, that is, JCV serostatus does not identify all patients infected with JCV and it is important not to conflate a negative JCV antibody result with an absence of JCV infection .…”