1. Division of Clinical Microbiology, Karolinska Institutet, F68 Karolinska University Hospital Huddinge, SE-141 86 Stockholm, Sweden
2. Clinical Protein Science, Department of Electrical Measurements, Lund University, SE-221 00 Lund, Sweden
3. Tripep AB, Hälsovägen 7, SE-141 57 Huddinge, Sweden
4. Department of Biochemistry, Uppsala University, SE-751 23 Uppsala, Sweden
5. Department of Clinical Virology, University of Göteborg, SE-413 46 Göteborg, Sweden
6. Institute for Medical Research, Katholieke Universiteit Leuven, Minderbroedersstraat 10, B-3000 Leuven, Belgium