Relationship of SV40 T-antigen expression in vitro to disorders of bone marrow function

Skin fibroblasts from patients with a variety of hematologic disorders were infected with SV40 virus in vitro in attempts to discover the reason for increased susceptibility of Fanconi anemia cells to this transforming virus. The proportion of skin fibroblasts expressing SV40 T-antigen by immunofluorescent methods was elevated in 12 patients with Fanconi anemia and in seven of nine obligate heterozygous relatives. Elevated expression was also observed in three patients with other hematological disorders at high risk of acute non-lymphocytic leukemia, but was not apparent in seven sporadic aplastic anemia patients or four of their relatives. T-antigen expression was elevated in about one-half of patients with thrombocytopenia-absent radius syndrome and related conditions, with familial aplastic anemia, and in their normal relatives. In the conditions under study, elevated T-antigen expression seemed clearly correlated with predisposition to leukemia, which may be genetically determined, but it was not associated with cytogenetic or anemic manifestations.