Sjögren's syndrome (dryness of eyes, mouth, and other mucous membranes) may be associated with disease of joints, blood, internal organs, skin, and central and peripheral nervous systems. We reviewed 33 cases of primary Sjögren's syndrome and peripheral neuropathy evaluated by neurologic examinations and EMG at the Mayo Clinic from 1976 to 1988, and studied sural nerve biopsy specimens in 11 of them. Symmetric sensorimotor polyneuropathy occurred most frequently, followed by symmetric sensory neuropathy. Autonomic neuropathy, mononeuropathy, or cranial neuropathy (especially trigeminal neuropathy) was superimposed on generalized neuropathy in approximately one-fourth of patients. The course generally was slowly progressive, except for a few patients who may have improved with prednisone therapy. Although spinal ganglion involvement might have accounted for some of the clinical and neurophysiologic findings, we found evidence that necrotizing vasculitis was involved in fiber degeneration. All nerve biopsies revealed perivascular inflammatory infiltrates and other vessel abnormalities, which were diagnostic in two cases and strongly suggestive of necrotizing vasculitis in six cases. Axonal degeneration predominated over demyelination and sometimes was focal or multifocal. In neuropathy of unknown cause, particularly if it is sensory, autonomic, or involves trigeminal nerve, consider Sjögren's syndrome.

Abstract-The clinical and radiologic impact of developing neutralizing antibodies (NAbs) to interferon beta (IFN␤) while on this therapy for multiple sclerosis (MS) is assessed. On the basis of Class II and III evidence, it is concluded that treatment of patients with MS with IFN␤ (Avonex, Betaseron, or Rebif) is associated with the production of NAbs (Level A). NAbs in the serum are probably associated with a reduction in the radiographic and clinical effectiveness of IFN␤ treatment (Level B). In addition, the rate of NAb production is probably less with IFN␤-1a treatment than with IFN␤-1b treatment, although the magnitude and persistence of this difference is difficult to determine (Level B). Finally, it is probable that there is a difference in seroprevalence due to variability in the dose of IFN␤ injected or in the frequency or route of its administration (Level B). Regardless of the explanation, it seems clear that IFN␤-1a (as it is currently formulated for IM injection) is less immunogenic than the current IFN␤ preparations (either IFN␤-1a or IFN␤-1b) given multiple times per week subcutaneously (Level A). However, because NAbs disappear in some patients even with continued IFN␤ treatment (especially in patients with low titers), the persistence of this difference is difficult to determine (Level B). Although the finding of sustained high-titer NAbs (Ͼ100 to 200 NU/mL) is associated with a reduction in the therapeutic effects of IFN␤ on radiographic and clinical measures of MS disease activity, there is insufficient information on the utilization of NAb testing to provide specific recommendations regarding when to test, which test to use, how many tests are necessary, or which cutoff titer to apply (Level U).