Pseudomembranous conjunctivitis following bone marrow transplantation: immunopathological and ultrastructural study of one case.

Pseudomembranous conjunctivitis (PMC) is a rare ophthalmic lesion usually caused by infectious agents such as streptococcus, Klebsiella, Chlamydia, or adenovirus. It can also be associated with skin lesions of toxic epidermal necrolysis (TEN) and graft-versus-host-disease (GVHD). We report the pathological study of a patient with PMC and GVHD who had a conjunctival biopsy before death. This allowed us to differentiate this form of PMC from PMC of infectious origin, and to find within the epithelium characteristic features of acute GVHD and mononuclear cells expressing natural-killer markers. This suggests that this form of PMC resulted from a very acute, cytotoxic form of GVHD. Because PMC in bone marrow recipients can be related to infections, TEN, or acute GVHD, a systematic pathological study is required to guide the therapy.