Autoantibodies to the mitotic spindle apparatus in Mycoplasma pneumoniae disease

Antibodies to the mitotic spindle apparatus (MS) have been detected in only a very few patient sera studied for antinuclear antibodies by routine screening (G. A. McCarty, D. W. Velencia, and M. J. Fritzler, J. Rheumatol. 11:213-218, 1984). We found anti-MS antibodies to be quite common in sera from patients with Mycoplasma pneumoniae, especially in those who developed cold agglutinins (71%). Absorption experiments indicated that the formation of anti-MS antibodies is not triggered by epitopes on the M. pneumoniae surface. These antibodies were distinct from cold agglutinins, antibrain antibodies, and smooth-muscle antibodies. All patients previously reported to harbor anti-MS had clinical features compatible with a diagnosis of systemic lupus erythematosus, rheumatoid arthritis, or an evolving connective-tissue disorder. Such systemic disorders might develop in a small proportion of patients who have had M. pneumoniae illness.