Monday, 21 January 2013

Survey results: NABs

NABs = neutralizing anti-interferon beta antibodies. 

"NABs develop in anything from 2-35% of MSers on interferon-beta. The rate of NABs depends on the product of interferon beta you are on. NAB development is delayed and typically develop after 6 months of therapy. Depending on the levels of NABs they generally inhibit the action of interferon-beta. Hence MSers with NABs are much more likely to fail interferon therapy in the future, i.e. have relapses or develop lesions on MRI. NABs are a general problem with all biological therapies and develop in ~5% of MSers on natalizumab. Current European recommendations state MSers on interferon-beta or natalizumab therapy should be screened for NABs at 12 months and in the case of interferon-beta if negative again at 24 months. If you are found to be NAB positive a decision needs to made regarding your therapy. In general, NABs persist and hence most MSers who have NABs are offered another treatment."

"The problem is that NAB testing is not widely adopted. We therefore did this survey to see how aware you are of NABs and if monitoring of NABs is happening."




"Despite having had data on NABs and their impact on interferon-beta for decades too many MSers on IFNbeta don't know about them nor the possible effect they may be having on their own immune function."

"I have one MSer that I look after who developed NABs on interferon-beta and coincident with the appearance of NABs developed recurrent herpes infections; the outbreak of herpes was on an almost monthly basis. I am sure the latter occurred as the NABs inhibited or neutralized her own IFNbeta, which is an anti-viral, and allowed the virus to escape suppression by her own immune system. To treat her herpes infections I have had to put her on long-term anti-viral medication. I am sure if we could get rid of her NABs her own immune system would recover and function normally and suppress the herpes virus. This case has made me worry about the long-term effects of NABs to interferon-beta on immune function. Will MSers with NABs have a higher incidence of infections and cancers in the future? Will children born to mothers who have NABs have something wrong with their bones? NABs cross the placenta and will almost certainly neutralise IFNbeta in the developing foetus. IFNbeta is involved in bone development so the place to look for an effect on these transplacental NABs is the bones of children born to MSers with NABs. Unfortunately, nobody is specifically looking at present for any of these potential long-term adverse effects of NABs! I predict it is only a matter of time before we realise that NABs are bad for us!"

2 comments:

  1. NABs = ? we're not all up to speed with the acronyms... negative antibodies?
    Thanks

    ReplyDelete
    Replies
    1. Neutralizing antibodies they neutralize ie stop the effect (of beta interferon)

      Delete

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