Development of antigen-specific ELISA for circulating autoantibodies to extracellular matrix protein 1 in lichen sclerosus
Noritaka Oyama, … , Martin M. Black, John A. McGrath
Noritaka Oyama, … , Martin M. Black, John A. McGrath
Published June 1, 2004
Citation Information: J Clin Invest. 2004;113(11):1550-1559. https://doi.org/10.1172/JCI20373.
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Article Dermatology

Development of antigen-specific ELISA for circulating autoantibodies to extracellular matrix protein 1 in lichen sclerosus

Abstract

Lichen sclerosus is a common, acquired chronic inflammatory skin disease of unknown etiology, although circulating autoantibodies to the glycoprotein extracellular matrix protein 1 (ECM1) have been detected in most patients’ sera. We have examined the nature of ECM1 epitopes in lichen sclerosus sera, developed an ELISA system for serologic diagnosis, and assessed clinicopathological correlation between ELISA titer and disease. Epitope-mapping studies revealed that lichen sclerosus sera most frequently recognized the distal second tandem repeat domain and carboxyl-terminus of ECM1. We analyzed serum autoantibody reactivity against this immunodominant epitope in 413 individuals (95 subjects with lichen sclerosus, 161 normal control subjects, and 157 subjects with other autoimmune basement membrane or sclerosing diseases). The ELISA assay was highly sensitive; 76 of 95 lichen sclerosus patients (80.0%) exhibited IgG reactivity. It was also highly specific (93.7%) in discriminating between lichen sclerosus and other disease/control sera. Higher anti-ECM1 titers also correlated with more longstanding and refractory disease and cases complicated by squamous cell carcinoma. Furthermore, passive transfer of affinity-purified patient IgG reproduced some histologic and immunopathologic features of lichen sclerosus skin. This new ELISA is valuable for the accurate detection and quantification of anti-ECM1 autoantibodies. Moreover, the values may have clinical significance in patients with lichen sclerosus.

Authors

Noritaka Oyama, Ien Chan, Sallie M. Neill, Andrew P. South, Fenella Wojnarowska, Yoshio Kawakami, David D’Cruz, Kirti Mepani, Graham J. Hughes, Balbir S. Bhogal, Fumio Kaneko, Martin M. Black, John A. McGrath

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Figure 7

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Passive-transfer study using affinity-purified lichen sclerosus IgG in n...
Passive-transfer study using affinity-purified lichen sclerosus IgG in neonatal BALB/c mice. (A) Intradermal injection of affinity-purified lichen sclerosus IgG into BALB/c mouse caused extensive erythematous swelling with telangiectasie (left ear), whereas the control skin injected with either nonimmune human IgG exhibited no evidence of skin inflammation (right ear). This picture was taken at 28 days in a mouse that had received seven separate injections in both ears at days 0, 4, 8, 12, 16, 20, and 24. (B) Light microscopy of the mouse skin injected with affinity-purified lichen sclerosus IgG exhibited a pronounced inflammatory infiltration with edema and dilated blood vessels in the upper-middle dermis. The overlying epidermis showed mild acanthosis. (C) In contrast, the control skin injected with affinity-purified normal human IgG showed only a scanty perivascular infiltration in the dermis. (D) The mouse skin injected with affinity-purified lichen sclerosus antibodies revealed IgG deposition within the lower epidermis (arrows) and surrounding dilated dermal blood vessels (arrowheads). Asterisk indicates the injected site. Higher magnification views revealed an intracellular signal in basal keratinocytes and weaker staining in the suprabasal keratinocytes (E), as well as in the walls of dilated dermal blood vessels (F). (G) In contrast, the control injection with affinity-purified normal human IgG resulted in no immunolabeling. (H) At higher magnification, control injections only resulted in a nonspecific signal in the corneal layers. Scale bar: 50 ∝m.