Bullous pemphigoid associated with chronic B‐cell lymphatic leukaemia: the anti‐230‐kDa autoantibody is not synthesized by leukaemic cells

SIR, Eosinophilic pustular dermatosis (EPD) was originally reported in Japan, and is characterized by pruritic follicular papules on the face and trunk; eosinophilia in the peripheral blood is also frequently present. Since the late 1980s, there has been an increasing number of reports of EPD associated with HIV infection, suggesting that EPD is a dermatosis related to immune dysfunction. Although the aetiology of EPD still remains unclear, it has been reported that interleukin (IL)5 could play a critical part. IL-5 is one of the Th2 cytokines, and potentially mobilizes, differentiates, activates and aids survival of eosinophils. A 31-year-old woman noticed pruritic erythematous macules on both cheeks in November 1995; follicular papules and pustules later developed over the pre-existing erythematous lesions. On admission in September 1996, she had circinate erythematous plaques on the cheeks and forehead accompanied by follicular papules, pustules and vesicles, some of which fused to form blisters (Fig. 1a). Histopathological examination of a biopsy of the cheek skin revealed a subepidermal bulla containing eosinophils and mononuclear cells, and dense perivascular and perifollicular in®ltration of mononuclear cells and eosinophils (Fig. 1b). Taken together, a diagnosis of EPD was made. Her peripheral blood white cell count was 6 ́3 ́ 10/L (normal 4±11 ́ 10) with 3 ́7% eosinophils (normal 0±8%). The serum IgE was elevated to 470 IU/mL (normal <165). She was negative for HIV antibody. Liver and renal function, serum electrolytes and urinalysis were normal. She was treated with a topical corticosteroid, oral minocycline and indomethacin for 4 weeks without clinical improvement. She was then given prednisolone 35 mg/day and dapsone 75 mg/day, which resulted in a gradual subsidence of the erythematous plaques and papules, pustules and vesicles. The oral prednisolone was tapered as the eruption improved and, after 3 months, it was discontinued. Before systemic administration of prednisolone, we collected and pooled blister ̄uid from her cheek to examine immunological activity. Her peripheral blood mononuclear cells (PBMC) were cultured for 72 h in vitro in the presence of the blister ̄uid (1 : 100, at ®nal concentration). Reverse transcription±polymerase chain reaction revealed that IL-5 mRNA was upregulated in PBMC treated with blister ̄uid, while no IL-5 mRNA was detected in PBMC treated with her serum. Representative results of two independent experiments are shown in Figure 2. At the same time, enzyme-linked immunosorbent assay detected IL-5 protein in the culture supernatant of PBMC treated with the blister ̄uid, but not in the serum-treated PBMC culture supernatant. This result suggested that T lymphocytes in the PBMC were activated to produce IL-5 in response to a putative antigen in the blister. However, blister ̄uid from untreated bullous pemphigoid did not induce IL-5 mRNA in the patient's PBMC, and the patient's blister ̄uid did not induce IL-5 mRNA in a healthy donor's PBMC. Although HLA typing of the patient was not British Journal of Dermatology 1999; 141: 154±179.