Abstract To clarify the clinical features of
myositis complicated with primary Sjögren's syndrome (SS), we studied 89 patients with Sjögren's syndrome (one male and 88 females; mean age 56.0 ± 15.31 years).
Myositis was diagnosed from clinical findings, muscle
enzymes, electromyographic findings, and muscle biopsy findings.
Myositis was diagnosed in 5 of 89 SS patients (5.6%). One patient developed
myositis 7 months after the onset of SS. The other four patients were diagnosed with
myositis and SS simultaneously.
Muscular weakness was mild and slowly progressive over 4-14 months (mean 8.4 months). All patients were able to walk without any assistance at the start of
prednisolone therapy. Muscular
enzymes were slightly elevated (from 1.5- to 12-fold). All patients tested negative for anti-Jo1 antibody and tested positive for
antinuclear antibody. Anti-Ro(SSA) antibody was positive in 4/5 (90%); anti-La(SSB) was positive in 2/5 (40%). Although the clinical features of all patients met the criteria for
polymyositis of Bohan, they responded well to small or moderate doses of
prednisolone, which could be decreased without a recurrence of
muscular weakness in all patients.
Myositis with Sjögren's syndrome showed relatively moderate symptoms and responded well to
prednisolone. A prospective follow-up of patients may provide further information.