Figure 4
NMDAR IgG auto-antibody in CSF. Using a cell-based assay, NMDAR IgG auto-antibody in CSF with reflex to titre was detected using a commercial anti-glutamate receptor NR1 subunit kit (Euroimmune AG. Luebeck, Germany) by indirect immunofluorescence. The CSF sample of the patient was incubated with NMDAR substrate antigen on the biochip slide in the following dilutions: undiluted, 1:10, 1:20, and 1:40 in PBS-Tween at room temperature for 30 minutes. After the incubation, the biochip slides were washed with PBS-Tween to remove any unbound antibodies. The biochip slide was again incubated with fluorescent-labelled anti-human IgG for 30 minutes at room temperature and washed with PBS-Tween and mounted in buffered glycerin. The reaction was made visible under a fluorescence microscope. The presence of anti-NMDAR antibody is shown as smooth fine granular fluorescence in the cytoplasm of transfected HEK 293 cells, while there is no fluorescence in the negative control. Positive fluorescence was demonstrated in (A) undiluted CSF; (B) 1:10 diluted CSF; and (C) 1:20 diluted CSF; no fluorescence was present in the negative control (CSF, undiluted), supplied with the kit (D).