Vacuolated lymphocytes are a common finding in peripheral blood and bone marrow smears of patients with storage diseases. We analyzed the vacuolated peripheral blood lymphocytes of a child with infantile GMI Gangliosidosis type 1, a rare autosomal recessive lipid storage disease due to deficiency of β-galactosidase.

A nine month old child presented with prominent hepatosplenomegaly, coarse orofacial features with a dull looking aspect, macroglossy, bypotonia, feeding difficulties, kyphoscoliosis, cherry red macular spots and deafness. Bone marrow aspiration showed several “foam cells”. On peripheral blood smears vacuolated lymphocytes were abundant (70% of the lymphocytes). Absolute numbers of peripheral blood lymphocytes were within the limits of normal (3.52 109/L); phenotypic analysis revealed a slightly decreased percentage of T-cells (CD3=56%), an elevated CD4/CD8 ratio (6.38) with 51% T-helper (CD4+) and 8% T-suppressor (CD8+) lymphocytes and an elevated number of B-cells(CD19=35%) with 2% of CD10-positive cells. Since flow cytometry could not distinguish vacuolated from morphologically normal lymphocytes, immunophenotyping was also performed on peripheral blood smears of dextran concentrated leucocytes using the APAAP-method. Nearly all (<95%) vacuolated lymphocytes expressed only CD3 and CD4 while no positivity for CD8, CD19, CD20, CD10, CD56 or CD16 could be demonstrated.

To our knowledge, no similar immunophenotypic evaluation of circulating lymphocytes in infantile GMI Gangliosidosis type 1 has been discribed. Further observations in infantile GMI Gangliosidosis type 1 and other storage diseases are needed to confirm if our findings are disease specific, related to the functional activity of the CD4+ lymphocytes or to the duration of the disease.