Rapid immunologic diagnosis of classic late infantile neuronal ceroid lipofuscinosis

Objective: To establish a new method for rapid diagnosis of late infantile neuronal ceroid lipofuscinosis (LINCL, CLN2) using specific polyclonal anti bodies against the CLN2 gene product. Methods: Cells and tissues were obtai ned from five patients with LINCL, two with variant type NCL, three with ot her lysosomal storage diseases, and eight control subjects. Two antibodies were raised against N- and C-terminal peptide fragments of the normal produ ct of the CLN2 gene. The authors examined the possibility of diagnosis of L INCL with immunostaining and immunoblotting using specific antibodies made of the recently identified defective gene in LINCL. Results: Immunoreactivi ty with these antibodies showed the absence or marked reduction of CLN2 imm unoreactivity in the lymphocytes, lymphoblasts, and fibroblasts of all five patients with LINCL examined. Conclusions: These results indicate the usef ulness of this diagnostic method based on the changes in CLN2 immunoreactiv ity. This relatively simple, specific, and cost-effective method is a promi sing diagnostic tool for this disease, although additional studies are nece ssary.