Recent manometric and radiological studies suggest that the upper oesophageal sphincter has poor compliance in patients with a pharyngeal (Zenker's) diverticulum. To test the hypothesis that this phenomenon is related to structural changes within the cricopharyngeus muscle we examined, histologically, muscle strips from 14 patients with a Zenker's diverticulum and compared them with control tissue obtained at autopsy from 10 non-dysphagic individuals. The cricopharyngeus muscle from patients and controls differed from inferior constrictor muscle by virtue of type 1 fibre predominance and greater fibre size variability. Ragged red fibres and nemaline bodies are a normal finding in the cricopharyngeus. Marked differences were observed in the cricopharyngeus muscle of Zenker's patients which demonstrated fibro-adipose tissue replacement and fibre degeneration. It is concluded that these structural changes may account for the observed diminished upper oesophageal sphincter opening and dysphagia in patients with Zenker's diverticulum.
Herein we report a case of sporadic inclusion-body myositis (sIBM) occurring at an unusually young age in a patient with primary Sjögren syndrome, and use the case to explore possible shared mechanisms for disease susceptibility. Possible factors may include the association of both conditions with the 8.1 ancestral haplotype; the presence of anti-cN1A antibodies, which, although considered specific for sIBM, are also seen in pSS; and the shared association with T-cell large granular lymphocyte leukemia (T-LGLL). Further evaluation of this patient did in fact reveal underlying T-LGLL and mechanisms by which T cells in sIBM may escape immune regulation and contribute to disease phenotype are explored. Despite myofiber infiltration with CD8-positive T cells in sIBM, and, although sIBM is traditionally considered treatment-refractory, we report a significant response to the anti-CD20 monoclonal antibody, rituximab, and discuss possible mechanisms by which this response may be mediated.
K E Y W O R D Santi-cN1A, inclusion-body myositis, primary Sjögren syndrome, rimmed vacuoles, rituximab
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