Pemphigus foliaceus associated with anti-NXP2 autoantibody-positive dermatomyositis.

SHORT COMMUNICATION Pemphigus foliaceus (PF) is one of the autoimmune blistering diseases (ABDs) characterised by autoantibodies (Abs) binding to desmoglein (Dsg) 1, resulting in acant-holysis and intraepidermal blistering. Several other au-toimmune diseases have been reported to occur in patients with ABDs, such as rheumatoid arthritis, systemic lupus erythematosus, and Grave's disease (1). However, ABD associated with dermatomyositis (DM) is rare. We report here the first case in which the Ab of DM is identified. A 39-year-old Japanese woman with a 4-month history of skin eruptions was referred to our hospital in July 2007. Physical examination showed pruritic malar erythema on the face, including the medial canthi of the eyes and alar part of the nose (Fig. 1A), diffuse alopecia and erythema on the scalp, and Gottron's papu-les on the dorsum of the hands (Fig. 1B). Muscle weakness and dysphagia were not present, and cutaneous calcinosis was not found. She had no medical history of note. A biopsy specimen from the erythematous lesion on the cheek showed mild basal vacuolar change and sparse superficial perivascular infiltration of lymphocytes. Direct immunofluorescence microscopy revealed no deposition of immunoglobulin or complement. Laboratory investigations showed raised levels of creatine kinase (514 IU/l; normal 45–163) and aldolase (10.7 IU/l; 2.1–6.1). Circulating Abs against Jo-1, SS-A/Ro, and SS-B/La were not detected using enzyme-linked immunosorbent assay (ELISA). Anti-nuclear matrix protein 2 Ab (anti-NXP2 Ab) was identified by immunoprecipitation assay with 35S-labelled K562 cell extracts (2). Biopsy from the left quadriceps femoris muscle showed no apparent findings of myositis. We diagnosed the patient with clinically amyopathic dermatomyositis (CADM). Screening for internal malignancy and interstitial lung disease was negative. We treated the patient with topical, not systemic, corticosteroids. The skin eruptions of DM gradually improved from April 2008 and had almost disappeared in June 2009. Anti-NXP2 Ab was no longer detected in the sera in June 2011, and DM has not relapsed for 3 years. In December 2009, she noticed mild erythema on the chest and back. She presented with some erythema and erosions on the chest and back (Fig. 1C) in June 2010. There was no mucous membrane involvement. Histopathological examination of a biopsy specimen showed acantholysis and superficial split in the granular layer (Fig. 1D). Direct immunofluorescence showed intercellular staining for IgG and C3 in the epidermis. Anti-Dsg Ab ELISA was positive for anti-Dsg 1 (index value: 146; cutoff: 14) but negative for anti-Dsg 3. Based on these …