Therapeutic Plasma Exchange in Multiple Sclerosis Patients with Abolished Interferon-beta Bioavailability
Natasa Giedraitiene, Gintaras Kaubrys, Rasa Kizlaitiene, Loreta Bagdonaite, Laimonas Griskevicius, Vilma Valceckiene, Mindaugas Stoskus
(Clinic of Neurology and Neurosurgery, Faculty of Medicine, Vilnius University, Center of Neurology, Vilnius University Hospital Santariskiu Clinics, Vilnius, Lithuania)
Med Sci Monit 2015; 21:1512-1519
Neutralizing antibodies (NAb) to interferon-beta (IFN-β) are associated with reduced bioactivity and efficacy of IFN-β in multiple sclerosis (MS). The myxovirus resistance protein A (MxA) gene expression is one of the most appropriate markers of biological activity of exogenous IFN-β. We hypothesized that therapeutic plasma exchange (TPE) can restore the ability of IFN-β to induce the MxA mRNA expression and that maintenance plasmapheresis can sustain the bioavailability of IFN-β.
MATERIAL AND METHODS: Eligible patients underwent 4 primary separate plasma exchange sessions. After the induction TPE sessions, they were transferred to maintenance plasmapheresis. Bioactivity of IFN-β was expressed as in vivo MxA mRNA induction in whole blood using RT-qPCR.
RESULTS: Six patients with low IFN-β bioavailability detected by the MxA mRNA response were included. Four patients became biological responders after induction plasmapheresis. In 2 patients an increase of MxA mRNA expression was found, but the values persisted below the cut-off and the patients remained as “poor biological responders”. The effect of maintenance plasmapheresis was transient: MxA mRNA expression values reverted to the baseline levels after 1–2 months.
CONCLUSIONS: Therapeutic plasma exchange is able to restore the bioavailability of IFN-β in the majority of studied patients, but the effect of TPE on the IFN-β bioavailability was transient.
Keywords: Antibodies, Neutralizing, Interferon-beta, Multiple Sclerosis, Plasma Exchange