Pericellular glycosaminoglycans in cultured human cells. A possible source of error in prenatal diagnosis of mucopolysaccharidoses.

Normal fibroblasts and amniotic fluid cells, and cells from patients with Mucopolysaccharidosis type I and II, were cultured in the presence of 35SO4. After harvesting by trypsinization, the radioactivity was recovered from the intracellular and pericellular pool of glycosaminoglycans. The amount of incorporated radioactivity in these respective pools was 1 : 2.3 in normal fibroblasts and 1 : 7.2 in control amniotic fluid cells. Incorporation in the pericellular pool was not elevated in cells from patients with Mucopolysaccharidosis type I and II, in contrast to incorporation in the intracellular pool. Studies on different methods of harvesting showed that reliable prenatal analysis can be performed only if the pericellular pool is removed by trypsinization. Amniotic fluid cells from a pregnancy carrying a fetus affected with Hurler's disease revealed the expected increased level of 35SO4 incorporation if the cells were trypsinized, but the intracellular accumulation of glycosaminoglycans was obscured by the pericellular pool if the cells were harvested by scraping.