The lupus band test in oral mucosa, conjunctiva and skin.

Abstract

The prevalence and clinical significance of subepithelial immunoglobulin and complement deposition (the lupus band) were examined in the uninvolved sun-protected skin of the forearm, the uninvolved sun-protected lip mucosa and sun-protected bulbar conjunctival mucosa in systemic lupus erythematosus (SLE) and chronic cutaneous lupus erythematosus (CCLE). In SLE, linear deposition of an immunoreactant at the BMZ was detected in 32% (6/19) of skin biopsies; 21% (4/19) of lip mucosal biopsies and 42% (5/12) of conjunctival biopsies. There was no significant difference in the sensitivity of the test at different sites in SLE and no correlation between a positive test in skin, lip or conjunctiva and clinical mucosal involvement. In CCLE, linear deposition of an immunoreactant at the BMZ was found in 3% (1/32) of skin biopsies; 3% (1/29) of lip mucosal biopsies and 50% (10/20) of conjunctiva and clinical mucosal involvement. In the conjunctiva, IgG was present in all but one of the biopsies and was the only immunoreactant in 90% (9/10) of positive CCLE biopsies and 60% (3/5) of positive SLE biopsies. In lupus erythematosus immunoreactants may be deposited in the basement membrane zone beneath non-keratinizing mucosal surfaces of the lip and the eye as well as the skin. In CCLE, the test may be positive in conjunctiva when skin and lip are negative.