To describe the major clinical features of patients with high titers of anti-Ki antibodies.
Four of 172 patients with connective tissue diseases showed high titers (> 1/256) of anti-Ki antibodies. In these four patients, (1) the common clinical findings were alopecia, disabling chronic fatigue, muscle weakness, tenosynovitis, dry mouth, and abnormal glucose tolerance test; (2) anti-Ki antibodies were positive not only in patients with sicca lupus, but also in those with nonsicca lupus. In this case, anti-insulin receptor antibody was positive and there was a regulatory insufficiency of the pituitary. (3) Symptoms of anti-Ki antibodies share many clinical and laboratory features of chronic fatigue syndrome and fibromyalgia, that is, they may share either a common etiologic agents or a common pathogenetic pathway or both.
"Anti-Ki antibody" syndrome may be a subset of sicca lupus.