Conclusion
Our results suggest that IgGs isolated from the sera of NBD patients have a neurotoxic activity that is presumably mediated by apoptotic mechanisms.
Methods
To delineate the potential pathogenic activity of serum antibodies on neurons, pooled sera from seven NBD patients and seven healthy controls were divided into purified immunoglobulin G (IgG) and IgG-depleted serum fractions, and each fraction was administered to cultured SH-SY5Y neuroblastoma cells. Cell death was evaluated with a toxicity assay and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining. Moreover, expression levels of several apoptosis markers were evaluated with real time polymerase chain reaction (PCR).
Results
Administration of NBD IgG to cultured SH-SY5Y cells induced significantly increased cell death and apoptosis compared with other treatments. NBD IgG also enhanced the mRNA expression levels of major apoptosis and cell survival pathway factors.