Antinuclear factor in NZB-NZW mice: incidence and in vitro effects.

After the age of 6 months, NZB/NZW mice develop almost 100% incidence of serum antinuclear factor (ANF) which is located in the IgG immunoglobulin fraction, binds guinea-pig complement and gives homogeneous, membranous and speckled immunofluorescent nuclear staining patterns. No specific cytotoxic activity against homologous kidney cells was detected in serum from these mice, but their lymphoid cells clustered around a proportion of kidney cells which subsequently degenerated.