Context: Discoid lupus erythematosus is a chronic inflammatory skin disorder presenting with scarring lesions that occur predominately on sun exposed areas of the face and scalp.
Case report: A 22-year-old male was evaluated after presenting with reddish-purple, atrophic and erythematous plaques on the scalp, with loss of hair within the plaques. Biopsies for hematoxylin and eosin examination, direct immunofluorescence and immunohistochemistry analysis were performed. The hematoxylin and eosin staining demonstrated classic features of cutaneous lupus. Direct immunofluorescence revealed strong deposits of immunoglobulins IgG and IgM, fibrinogen and Complement/C3, present in 1) a shaggy pattern at the epidermal basement membrane zone, and 2) focal pericytoplasmic and perinuclear staining within epidermal keratynocytes. Immunohistochemisty staining revealed strongly positive staining with antibodies to cyclooxygenase-2, Zeta-chain-associated protein kinase 70, and HLA-DPDQDR in areas where the inflammatory infiltrate was predominant, as well as around dermal blood vessels and within the dermal extracellular matrix.
Conclusions: Noting the autoimmune nature of lupus and its strong inflammatory component, we present a patient with active discoid lupus erythematosus and strong expression of Zeta-chain-associated protein kinase 70, cyclo-oxygenase-2, and HLA-DPDQDR in the inflammatory areas. We suggest that these molecules may play a significant role in the immune response of discoid cutaneous lupus, possibly including 1) the biosynthesis of the prostanoids and 2) activation of the signaling cascade in response to T-lymphocyte receptor stimulation.
Keywords: COX-2; HLA-DPDQDR; Zap 70; autoantibodies; discoid lupus erythematosus; prostanoids.