1. Department of Allergology (E.M.H., A.A.J.M.v.d.V., R.G.P.), University Medical Center Groningen, University of Groningen, Netherlands.
2. Department of Pathology and Medical Biology, Division of Pathology (R.M.), University Medical Center Groningen, University of Groningen, Netherlands.
3. Department of Neurosurgery, Carl von Ossietzky University Oldenburg, Germany (R.M.).