Immunohistochemical evaluation of conjunctival fibrillin-1 in Marfan syndrome

Objective: To evaluate status of conjunctival fibrillin-1 in patients with Marfan syndrome with ectopia lentis. Methods: Frozen sections of conjunctiva from 6 patients with Marfan syndrome with ectopia lentis and from 15 age-matched control subjects were stained with mouse antihuman fibrillin-1 antibody, using an avidin biotin immunoperoxidase technique. The fibrillin-1 staining characteristics of conjunctiva were analyzed with the light microscope. Results: All the fresh frozen sections of conjunctival samples from control subjects demonstrated a characteristic pattern of fibrillin-1 staining. We observed a woven network of thin fibrils of uniform thickness surrounding collagen bundles. The fresh frozen samples from patients with Marfan syndrome showed consistent qualitative differences in fibrillin-1 staining when compared with samples from control subjects. The fibrils were longer and straighter than normal, varied in caliber, and showed fewer tendencies to form a woven pattern. Conclusions: Consistent, qualitative abnormalities in fibrillin-1 staining pattern can be seen in the conjunctiva of patients with Marfan syndrome with ectopia lentis. Conjunctival biopsy deserves further investigation as a diagnostic modality for Marfan syndrome in patients with ectopia lentis.