<p> Piepgras et al. 1</p><p>Appendix e-2</p><p>Intrathecal immunoglobulin A and G antibodies to synapsin in a patient with limbic encephalitis</p><p>Johannes Piepgras, Markus Höltje, Carolin Otto, Hendrik Harms, Annyesha Satapathy, Fabrizia Cesca, Fabio Benfenati, Daniel Gitler, Andreas Pich, Johannes- Friedrich Zander, Gudrun Ahnert-Hilger, Klemens Ruprecht</p><p>Table 1</p><p>Levels of immunoglobulin G to voltage-gated potassium channels in cerebrospinal fluid and serum</p><p>Aug. 7th Aug. 19th October November January June </p><p>2013 2013 2013 2013 2014 2014 CSF 17 9 7 2 4 <1 (pmol/l) Serum <1 27 <1 <1 <1 <1 (pmol/l)</p><p>Levels of immunoglobulin (Ig)G to voltage-gated potassium channels (VGKC) in cerebrospinal fluid (CSF) and serum as detected by radioimmunoassay (RIA) in a patient with limbic encephalitis and antibodies to synapsin. In CSF, values above 2 pmol/l, and in serum, values above 85 pmol/l are considered elevated. Piepgras et al. 2</p><p>Table 2-5</p><p>Titers of immunoglobulin (Ig)A and IgG antibodies to synapsin Ia and Ib, total </p><p>IgA and IgG concentration, and antibody indices (AIs) in paired cerebrospinal fluid (CSF) and serum samples of a patient with limbic encephalitis associated with antibodies to synapsin</p><p>Table 2</p><p>Synapsin Ia IgA</p><p>August 2013 October 2013 January 2014 June 2014 Antibody titer 1:1000 1:1000 1:1000 1:3200 CSF Antibody titer 1:1000 1:3200 1:1000 1:3200 serum Total IgA 0.127 0.158 0.04 0.039 CSF (mg/ml) Total IgA 2.22 2.15 2.3 1.62 serum (mg/ml) Antibody index 17.5 4.2 58 41</p><p>Table 3 Piepgras et al. 3</p><p>Synapsin Ib IgA</p><p>August 2013 October 2013 January 2014 June 2014 Antibody titer 1:10000 1:3200 1:320 1:1000 CSF Antibody titer 1:3200 1:3200 1:320 1:320 serum Total IgA 0.127 0.158 0.04 0.039 CSF (mg/ml) Total IgA 2,22 2,15 2,3 1,62 serum (mg/ml) Antibody index 54 13 58 130</p><p>Table 4</p><p>Synapsin Ia IgG</p><p>August 2013 October 2013 January 2014 June 2014 Antibody titer 1:32000 1:32000 1:3200 1:10000 CSF Antibody titer 1:10000 1:10000 1:3200 1:3200 serum Total IgG 0.217 0.181 0.15 0.133 CSF (mg/ml) Total IgG 21.9 9.85 8.37 8.33 serum (mg/ml) Antibody index 355 174 58 130</p><p>Table 5</p><p>Synapsin Ib IgG</p><p>August 2013 October 2013 January 2014 June 2014 Antibody titer 1:10000 1:32000 1:10000 1:10000 CSF Antibody titer 1:3200 1:10000 1:3200 1:3200 Piepgras et al. 4 serum Total IgG 0.217 0.181 0.15 0.133 CSF (mg/ml) Total IgG 21.9 9.85 8.37 8.33 serum (mg/ml) Antibody index 347 174 58 208</p><p>Antibody titers were obtained by incubating HEK293 cells transfected with either synapsin Ia or synapsin Ib plasmids with increasing dilutions of CSF or serum followed by a secondary anti-human IgA or IgG fluorescent antibody. Antibody indices were calculated using the formula: AI = (anti-synapsin titer CSF-1/anti-</p><p>-1 synapsin titer serum )/(total Ig CSF/total Ig serum). AI values above 4 are considered as evidence of an intrathecal antibody synthesis.1</p><p>REFERENCE</p><p>1. Reiber H, Lange P. Quantification of virus-specific antibodies in cerebrospinal fluid and serum: sensitive and specific detection of antibody synthesis in brain. Clin </p><p>Chem 1991;37:1153-1160.</p>