Primary Sjögren's syndrome associated with inclusion body myositis

To describe three new patients with inclusion body myositis (IBM) associated with primary Sjögren's syndrome (pSS) and summarize the clinical and serological picture for all six patients reported so far.

Three out of 518 (0.6%) pSS patients followed in our department over a period of 15 yr (1985-2000) also presented IBM. The diagnosis was based on histological criteria. Previous reports described four more patients with IBM associated with pSS. Five out of six were females; the mean age of IBM onset was 53.3+/-14.0 yr and the disease duration 8.0+5.8 yr.

Four out of six patients presented IBM several years after the onset of pSS. Four out of six patients presented extraglandular manifestations, such as arthralgias, vitamin B12 deficiency, interstitial kidney disease and biliary cirrhosis. The serological picture did not differ significantly from that observed in pSS alone.

Although rare, IBM may be seen in patients with pSS and it affects predominantly women. The clinical and pathological pictures do not differ from those observed in idiopathic IBM. A common autoimmune pathway in these two diseases, but no definite conclusions can be drawn.