Photoprovocation test and immunohistochemical analysis of inducible nitric oxide synthase expression in patients with Sjogren's syndrome associated with photosensitivity

Abstract

Our results indicate that photosensitivity exists in certain primary SS patients, and that UV is critical to the development of AE in SS, probably through a pathological mechanism distinct from that in LE.

Inducible nitric oxide synthase in pityriasis lichenoides lesions

“…iNOS expression was also observed in three normal skin samples at the upper epidermal layers. This pattern of iNOS expression in healthy epidermis was already reported by Tsukazaki et al 21 Such difference between PL and normal skin groups on epidermal iNOS expression was probably related to the inflammatory process of PL, and not because of epidemiological features of patients. The mean age of the PL group was smaller (21.85 years) than the control group (38.8 years), although there is some evidence that aging process is accompanied by a spontaneous induction of iNOS mRNA 23 …”

“…On the other hand, iNOS generates higher levels of NO in a calcium‐independent manner and is involved in inflammatory and pathological conditions 17–30 . In 1992, Heck et al reported the NO synthesis by normal human skin 31 .…”

“…In 1992, Heck et al reported the NO synthesis by normal human skin 31 . Since then, this molecule has been regarded as a key factor in several skin reactions, modulating the skin response to external stimuli such as infections, heat, ultraviolet light and wound healing 17–30 . Actually, all three NOS isoforms are expressed in the skin.…”

“…Actually, all three NOS isoforms are expressed in the skin. Disturbances in the signaling cascade of NO and reactive nitrogen intermediates have been shown to be associated with skin diseases and disorders 17–30 …”

Nitric Oxide Therapy for Dermatologic Disease

“…Inappropriate iNOS upregulation is implicated in such wide-ranging pathophysiologic conditions as: Cutaneous lupus erythematosus [3];Inflammatory skin disorders: psoriasis, atopic dermatitis, irritant and allergic contact dermatitis [4–6];Keloids [7];Morphea/scleroderma [8];Pemphigus vulgaris [9];Pityriasis lichenoides [10];Sjögren's syndrome [11];Stevens-Johnson syndrome/toxic epidermal necrolysis [12]. …”