Rapid immunologic diagnosis of classic late infantile neuronal ceroid lipofuscinosis.

Abstract

OBJECTIVE: To establish a new method for rapid diagnosis of late infantile neuronal ceroid lipofuscinosis (LINCL, CLN2) using specific polyclonal antibodies against the CLN2 gene product. METHODS: Cells and tissues were obtained from five patients with LINCL, two with variant type NCL, three with other lysosomal storage diseases, and eight control subjects. Two antibodies were raised against N- and C-terminal peptide fragments of the normal product of the CLN2 gene. The authors examined the possibility of diagnosis of LINCL with immunostaining and immunoblotting using specific antibodies made of the recently identified defective gene in LINCL. RESULTS: Immunoreactivity with these antibodies showed the absence or marked reduction of CLN2 immunoreactivity in the lymphocytes, lymphoblasts, and fibroblasts of all five patients with LINCL examined. CONCLUSIONS: These results indicate the usefulness of this diagnostic method based on the changes in CLN2 immunoreactivity. This relatively simple, specific, and cost-effective method is a promising diagnostic tool for this disease, although additional studies are necessary.