Ceroid pigment deposition in circulating blood monocytes and T lymphocytes in Hermansky-Pudlak syndrome: an ultrastructural study.

An electron microscopic study of peripheral leukocytes obtained from a 39 year old woman with Hermansky-Pudlak syndrome was performed. Ceroid pigment granules were found within the lysosomes in 3.5% of monocytes and 5.4% of lymphocytes. Infrequently, pigment granules were also found in the parallel tubular arrays of lymphocytes. The lymphocytes containing ceroid pigment granules were confirmed to be T cells by immunoelectron microscopy. It was speculated that intralysosomal accumulation of ceroid pigment granules in Hermansky-Pudlak syndrome may be due to lysosomal dysfunction.