Paraneoplastic pemphigus: a short review

摘要

Paraneoplastic pemphigus (PNP) is a fatal autoimmune blistering disease associated with an underlying malignancy. It is a newly recognized blistering disease, which was first recognized in 1990 by Dr Anhalt who described an atypical pemphigus with associated neoplasia. In 2001, Nguyen proposed the term paraneoplastic autoimmune multiorgan syndrome because of the recognition that the condition affects multiple organ systems. PNP presents most frequently between 45 and 70 years old, but it also occurs in children and adolescents. A wide variety of lesions (florid oral mucosal lesions, a generalized polymorphous cutaneous eruption, and pulmonary involvement) may occur in patients with PNP. The earliest and most consistent finding is severe stomatitis. There is a spectrum of at least five clinical variants with different morphology. Similarly, the histological findings are very variable. Investigations to diagnose PNP should include checking for systemic complications (to identify tumor), skin biopsies (for histopathological and immunofluorescence studies), and serum immunological studies. PNP is characterized by the presence of autoantibodies against antigens such as desmoplakin I (250 kD), bullous pemphigoid aniygen I (230 kD), desmoplakin II (210 kD), envoplakin (210 kD), periplakin (190 kD), plectin (500 kD), and a 170 kD protein. Unlike other forms of pemphigus, PNP can affect other types of epithelia, such as gastrointestinal and respiratory tract. Treatment of PNP is difficult, and the best outcomes have been reported with benign neoplasms that have been surgically excised. The first-line treatment is high-dose corticosteroids with the addition of steroid-sparing agents. Treatment failures are often managed with rituximab with or without concomitant intravenous immunoglobulin. In general, the prognosis is poor, not only because of eventual progression of malignant tumors but also because treatment with aggressive immunosuppression therapy often results in infectious complications, which is unfortunately at this time the most common cause of death in PNP.