Diagnosis of late infantile neuronal "ceroid-lipofuscinosis" from histochemical and ultrastructural changes in dental pulp

Infantile osteopetrosis complicating neuronal ceroid lipofuscinosis

An autopsy case of infantile osteopetrosis complicating neuronal ceroid-lipofuscinosis is reported. Autopsy revealed generalized sclerosis and thickening of cortical and spongy bones, formation of mineralized cartilagenous tissues, and narrowing of the marrow cavities associated with decreased hematopoietic cell components. Around the thickened bone trabecles, osteoclasts lacked a ruffled border and clear zone along the cell membrane facing the bone matrix surface. The brain was markedly atrophic with neuronal cell loss and focal gliosis, and the remaining neuronal cells accumulated brown granular pigments, which were confirmed histochemically and electron-microscopically to be ceroid and lipofuscin. In the cerebral medulla, the development of myelin sheaths was extremely poor. Also, the occurrence of Lex type glycolipids and GM3 and the apparent absence of cerebroside and cerebroside sulfate were proved by biochemical analysis, suggesting that the brain was still in a stage of embryonic development or still in the process of differentiation. Except for one suggestive case, this is the first case of complicating neuronal ceroid-lipofuscinosis in infantile osteopetrosis.

Elevated urinary dolichol excretion in the Hermansky-Pudlak syndrome. Indicator of lysosomal dysfunction

The Hermansky-Pudlak syndrome, a triad of albinism, platelets lacking dense bodies, and storage of ceroid-like material in tissues, occurs approximately once in 2,000 northwestern Puerto Ricans. The manifestations of storage disease are variable and include granulomatous colitis, restrictive lung disease, kidney failure, and cardiomyopathy. The autofluorescent material stored in the Hermansky-Pudlak syndrome is histochemically similar to that stored in neuronal ceroid/lipofuscinosis. The material in neuronal ceroid/lipofuscinosis contains dolichols, which are components of lysosomes, and patients show increased urinary excretion of dolichols. This study of 49 patients with the Hermansky-Pudlak syndrome found that urinary dolichol levels are increased in those patients with evidence of ceroid storage in the kidneys but are not elevated when storage occurs in tissues other than the kidneys. The excretion of ceroid was not influenced by the saturation state of dietary fat. A defect in processing of membranes of lysosomes, melanosomes, and dense bodies may be involved in the syndrome.