Intrathecal Immunoglobulin a and G Antibodies to Synapsin in a Patient with Limbic Encephalitis

Piepgras et al.

Appendix e-2

Intrathecal immunoglobulin A and G antibodies to synapsin in a patient with limbic encephalitis

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

Table 1

Levels of immunoglobulin G to voltage-gated potassium channels in cerebrospinal fluid and serum

Aug. 7th 2013 / Aug. 19th 2013 / October 2013 / November 2013 / January 2014 / June 2014
CSF (pmol/l) / 17 / 9 / 7 / 2 / 4 / <1
Serum (pmol/l) / 1 / 27 / 1 / 1 / 1 / 1

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.

Table 2-5

Titers of immunoglobulin (Ig)A and IgG antibodies to synapsin Ia and Ib, total 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

Table 2

Synapsin Ia IgA
August 2013 / October 2013 / January 2014 / June 2014
Antibody titer CSF / 1:1000 / 1:1000 / 1:1000 / 1:3200
Antibody titer
serum / 1:1000 / 1:3200 / 1:1000 / 1:3200
Total IgA
CSF (mg/ml) / 0.127 / 0.158 / 0.04 / 0.039
Total IgA serum (mg/ml) / 2.22 / 2.15 / 2.3 / 1.62
Antibody index / 17.5 / 4.2 / 58 / 41

Table 3

Synapsin Ib IgA
August 2013 / October 2013 / January 2014 / June 2014
Antibody titer CSF / 1:10000 / 1:3200 / 1:320 / 1:1000
Antibody titer
serum / 1:3200 / 1:3200 / 1:320 / 1:320
Total IgA
CSF (mg/ml) / 0.127 / 0.158 / 0.04 / 0.039
Total IgA serum (mg/ml) / 2,22 / 2,15 / 2,3 / 1,62
Antibody index / 54 / 13 / 58 / 130

Table 4

Synapsin Ia IgG
August 2013 / October 2013 / January 2014 / June 2014
Antibody titer CSF / 1:32000 / 1:32000 / 1:3200 / 1:10000
Antibody titer
serum / 1:10000 / 1:10000 / 1:3200 / 1:3200
Total IgG
CSF (mg/ml) / 0.217 / 0.181 / 0.15 / 0.133
Total IgG serum (mg/ml) / 21.9 / 9.85 / 8.37 / 8.33
Antibody index / 355 / 174 / 58 / 130

Table 5

Synapsin Ib IgG
August 2013 / October 2013 / January 2014 / June 2014
Antibody titer CSF / 1:10000 / 1:32000 / 1:10000 / 1:10000
Antibody titer
serum / 1:3200 / 1:10000 / 1:3200 / 1:3200
Total IgG
CSF (mg/ml) / 0.217 / 0.181 / 0.15 / 0.133
Total IgG serum (mg/ml) / 21.9 / 9.85 / 8.37 / 8.33
Antibody index / 347 / 174 / 58 / 208

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-synapsin titer serum-1)/(total Ig CSF/total Ig serum). AI values above 4 are considered as evidence of an intrathecal antibody synthesis.1

REFERENCE

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 Chem 1991;37:1153-1160.