PT  - JOURNAL ARTICLE
AU  - van der Meer, W
AU  - Jakobs, B S
AU  - Bocca, G
AU  - Smeitink, J A M
AU  - Schuurmans Steckhoven, J H
AU  - de Keijzer, M H
TI  - Peripheral blood lymphocyte appearance in a case of I cell disease
DP  - 2001 Sep 01
TA  - Journal of Clinical Pathology
PG  - 724--726
VI  - 54
IP  - 9
4099  - http://jcp.bmj.com/content/54/9/724.short
4100  - http://jcp.bmj.com/content/54/9/724.full
SO  - J Clin Pathol2001 Sep 01; 54
AB  - In general, peripheral blood smears are performed to obtain information with regard to various morphological features as an aid in the diagnosis of infection or malignancy. This report presents a patient with I cell disease (inclusion cell disease), a fatal lysosomal storage disorder caused by a defect in an enzyme responsible for the transfer of mannose-6-phosphate ligands to precursor lysosomal enzymes. As a consequence, most lysosomal enzymes are transported outside the cell instead of being correctly targeted into the lysosomes, resulting in the storage of macromolecules in lysosomes. I cell disease, with its heterogeneous clinical presentation, can be diagnosed by the presence of intracellular vacuole-like inclusions in lymphocytes and fibroblasts, high serum lysosomal enzyme activities, and a defect of N-acetylglucosamine-1-phosphotransferase. This report describes the morphological aspects of peripheral lymphocytes in a blood smear of a patient, the first clue to the final diagnosis of I cell disease. The observed vacuole-like inclusions in lymphocytes of this patient were negative for periodic acid Schiff (PAS) and Sudan black B staining, in contrast to earlier reports.