Ultrastructural pathology of human lymphocytes in lysosomal disorders: a contribution to their morphological diagnosis.

Ultrastructural examination of peripheral lymphocytes was performed in 28 cases of various lysosomal diseases, including infantile, late infantile and juvenile neuronal ceroid-lipofuscinoses (NCL), mucopolysaccharidoses (MPS), juvenile and adult metachromatic leukocystrophies (MLD), GM1-gangliosidosis, one patient with presumed mucolipidosis type IV, mucolipidosis type III, and glycogenosis type II. Based on our own observations on the ultrastructure of lymphocytes in lysosomal disorders, our results may be divided into the following 3 groups: 1. pathological findings with specific inclusions: each type of NCL, presumed mucolipidosis type IV, glycogenosis type II; 2 pathological findings with vacuoles: types I-H, II, III-A and III-B, IV, VI-A and VI-B of MPS, GM1-gangliosidosis; 3. apparently no pathological findings: juvenile and adult MLD, mucolipidosis type III, GM2-gangliosidosis, Gaucher disease. These results led us to conclude that morphological investigations utilizing lymphocytes do not always offer sufficient diagnostic information although easy accessibility favors diagnostic ultrastructural studies of lymphocytes. Such morphological studies should be supplemented by diagnostic biochemical methods.