A novel autoantibody causing a peripheral fluorescent antinuclear antibody pattern is specific for nuclear pore complexes.

We characterized serum from a patient with polymyositis, and found that it produced a peripheral (rim) fluorescent antinuclear antibody pattern on rat liver substrate. Indirect immunofluorescence analysis revealed a punctate pattern at the nuclear surface of PtK2, BHK-21, and HEp-2 cells. This pattern was still present after sequential extraction in situ with non-ionic detergent, DNase, RNase, and high ionic strength buffer (2M NaCl). Immunogold electron microscopic localization was specific for nuclear pore complexes. By immunoblot analysis, the antigens were polypeptides of 200 kd and 130 kd that were enriched in the nuclear fraction.