Interleukin-2 receptor beta and CD57 expression in orbital tissues from patients with chronic, stable thyroid-associated ophthalmopathy

In order to determine whether components of the interleukin-2 receptor (IL-2R) and lymphoid cells are present in extra ocular and periocular tissues from patients with chronic, stable thyroid-associated ophthalmopathy (TAO) we studied 16 specimens of extra ocular muscle and periorbital connective tissue from 14 patients with chronic, stable, TAO using an immunohistochemical assay and a panel of murine monoclonal antibodies reactive with IL-2R alpha and beta components and lymphoid cell surface markers. As controls we studied orbital tissues from 11 patients undergoing surgery for unrelated orbital disorders. All extra ocular muscle specimens from patients with TAO exhibited IL-2R beta expression primarily on the perimysium and endomysium surrounding the ocular muscle fasciculi and fibers of which nine specimens stained intensely. The Natural Killer (NK) cell marker CD57 was the most common cell surface antigen detected, in seven of nine specimens, whose localization often corresponded to that of IL-2R beta distribution. No IL-2R alpha expression was detected in any specimen. Seven of the 11 control specimens were positive for IL-2R beta but in a less intense fashion than in TAO specimens while no CD57 staining was detected. T cell, B cell, and cells of granulocyte and monocyte lineage were only occasionally found in both TAO and control specimens. The aberrant expression of IL-2R beta and CD57 which may be representative of NK cell presence in extra ocular muscle tissues from patients with stable, chronic TAO may play a role in the pathogenesis of the ophthalmopathy.(ABSTRACT TRUNCATED AT 250 WORDS)