Seroconversion of JCV antibodies is strongly associated to natalizumab therapy

JC Polyomavirus Infection Potentiated by Biologics

The risk of JC polyomavirus encephalopathy varies among biologic classes and among agents within the same class. Of currently used biologics, the highest risk is seen with natalizumab followed by rituximab. Multiple other agents have also been implicated. Drug-specific causality is difficult to establish because many patients receive multiple immunomodulatory medications concomitantly or sequentially, and have other immunocompromising factors related to their underlying disease. As use of biologic therapies continues to expand, further research is needed into pathogenesis, treatment, and prevention of JC polyomavirus encephalopathy such that risk for its development is better understood and mitigated, if not eliminated altogether.

Pre-clinical and Clinical Implications of "Inside-Out" vs. "Outside-In" Paradigms in Multiple Sclerosis Etiopathogenesis

Multiple Sclerosis (MS) is an immune-mediated neurological disorder, characterized by central nervous system (CNS) inflammation, oligodendrocyte loss, demyelination, and axonal degeneration. Although autoimmunity, inflammatory demyelination and neurodegeneration underlie MS, the initiating event has yet to be clarified. Effective disease modifying therapies need to both regulate the immune system and promote restoration of neuronal function, including remyelination. The challenge in developing an effective long-lived therapy for MS requires that three disease-associated targets be addressed: (1) self-tolerance must be re-established to specifically inhibit the underlying myelin-directed autoimmune pathogenic mechanisms; (2) neurons must be protected from inflammatory injury and degeneration; (3) myelin repair must be engendered by stimulating oligodendrocyte progenitors to remyelinate CNS neuronal axons. The combined use of chronic and relapsing remitting experimental autoimmune encephalomyelitis (C-EAE, R-EAE) (“outside-in”) as well as progressive diphtheria toxin A chain (DTA) and cuprizone autoimmune encephalitis (CAE) (“inside-out”) mouse models allow for the investigation and specific targeting of all three of these MS-associated disease parameters. The “outside-in” EAE models initiated by myelin-specific autoreactive CD4⁺ T cells allow for the evaluation of both myelin-specific tolerance in the absence or presence of neuroprotective and/or remyelinating agents. The “inside-out” mouse models of secondary inflammatory demyelination are triggered by toxin-induced oligodendrocyte loss or subtle myelin damage, which allows evaluation of novel therapeutics that could promote remyelination and neuroprotection in the CNS. Overall, utilizing these complementary pre-clinical MS models will open new avenues for developing therapeutic interventions, tackling MS from the “outside-in” and/or “inside-out”.

Incidence of seroconversion and sero-reversion in patients with multiple sclerosis (MS) who had been treated with natalizumab: A systematic review and meta-analysis

BACKGROUND

Natalizumab is a medication of choice for some patients with relapsing remitting (RR) form of multiple sclerosis (MS). John Cunningham virus (JCV) antibody status is important in cases who are treating with natalizumab. Different studies reported various rates of seroconversion and sero-reversion in patients who had been treated with natalizumab. As there is no systematic review reporting incidence of seroconversion and seroreversion in MS cases who were treated with natalizumab, we aimed to conduct this systematic review and meta-analysis to find pooled incidence of seroconversion and seroreversion in MS cases who were treated with natalizumab.

METHODS

PubMed, Scopus, EMBASE, CINAHL, Web of Science, Ovid, and google scholar were systematically searched. We also searched the gray literature including references from included studies, and conference abstracts which were published up to April 2019.

RESULTS

The incidence of seroconversion was reported between 6% and 41% and the incidence of seroreversion was reported between 1% and 11%. The pooled estimate of seroconversion incidence was 19% (95% CI: 13%-25%) (I² = 96.8%, P < 0.001) and the pooled estimate of seroreversion incidence was 5% (95% CI: 3%-8%) (I² = 72.2%, P < 0.001). Subgroup analysis by considering the country of the origin showed that the pooled incidence of seroconversion incidence during the studies was 6% in Asian countries and 21% in European/American countries. The incidence difference between subgroups was significant (p < 0.001).

CONCLUSION

Incidence of seroconversion in MS patients who had been treated with natalizumab is higher in European/American countries than Asian countries.