Clinical and immunological findings in 104 cases of paraneoplastic pemphigus.

BACKGROUND: Although there are many reports of sporadic patients with paraneoplastic pemphigus (PNP), only a few systematic studies on large cohorts of patients with PNP have been reported. OBJECTIVES: To analyse the clinical and immunological findings in a large cohort of patients with PNP. METHODS: This retrospective study consisted of 104 patients with PNP. Clinical and histopathological manifestations, associated neoplasms, complicating diseases, prognosis and results of immunofluorescence, immunoblotting and enzyme-linked immunosorbent assays (ELISAs) were analysed. RESULTS: The clinical and histopathological findings in this study were generally similar to those in previous reports. The most common associated neoplasms included malignant lymphomas, malignant solid tumours and Castleman disease, in that order, while 12 patients had no detectable tumours. Novel ELISAs for desmocollins (Dscs) showed that 19 (18·6%), 42 (41·2%) and 62 (60·8%) of 102 patients with PNP showed antibodies to Dsc1, Dsc2 and Dsc3, respectively. Thirty-two (60%) of 53 patients had antibodies to alpha-2-macroglobulin-like protein 1 (A2ML1). We found statistically significant correlations between positive desmoglein 3 reactivity and genital lesions, and between positive desmoglein 3 reactivity and bronchiolitis obliterans. CONCLUSIONS: We consider that antibodies to Dscs and A2ML1 are useful for the diagnosis of PNP.

Clinical and immunological profiles in 17 Japanese patients with drug-induced pemphigus studied at Kurume University.

BACKGROUND: Drug-induced pemphigus (DIP) shows clinical, histopathological and immunological features of pemphigus. However, little is known about immunological profiles in DIP. OBJECTIVES: To characterize clinical and immunological profiles in patients with DIP. METHODS: We studied 17 Japanese patients with DIP who were treated at Kurume University Hospital or who consulted from other hospitals between 1997 and 2012. Complicated diseases, clinical and histopathological manifestations, responsible drugs and findings in immunofluorescence, enzyme-linked immunosorbent assays (ELISAs), immunoblotting (IB) and prognosis were analysed. RESULTS: Eight of the 17 patients with DIP showed pemphigus foliaceus-like appearance, three showed pemphigus herpetiformis-like appearance, and six showed atypical bullous lesions. Responsible drugs were thiol-containing drugs in 16 patients (bucillamine in nine cases, d-penicillamine in four cases, and cetapril, thiopronine and captopril in one patient each), and a nonthiol drug, sulfasalazine, in one patient. By ELISAs and/or IB analyses, nine patients reacted only with desmoglein 1 (Dsg1), four reacted with Dsg1 and Dsg3, and four showed no specific reactivity. By IB of normal human epidermal extracts, in addition to positive reactivity with Dsg1, four patients with no detectable malignancy showed paraneoplastic pemphigus-like reactivity with the 210-kDa envoplakin and the 190-kDa periplakin. Four cases showed anti-Dsg3 antibodies without mucosal lesions. While 11 cases recovered after discontinuation of the causative drugs, six patients had a very protracted or intractable disease course, and might develop true pemphigus. CONCLUSIONS: The present study indicated that the majority of the patients with DIP studied showed a pemphigus foliaceus-type phenotype with anti-Dsg1 autoantibodies, caused by thiol-containing drugs.

Five Japanese cases of antidesmoglein 1 antibody-positive and antidesmoglein 3 antibody-negative pemphigus with oral lesions.

BACKGROUND: Oral mucosal lesions develop in pemphigus vulgaris, but not in pemphigus foliaceus. This clinical phenomenon is explained by the 'desmoglein (Dsg) compensation theory'. Dsg3 and Dsg1 are major autoantigens for pemphigus vulgaris and pemphigus foliaceus, respectively. Dsg3 is overexpressed and Dsg1 is weakly expressed on the oral mucosa. Thus, on the oral mucosa, suppression of Dsg3 function by anti-Dsg3 autoantibodies is not compensated by weakly expressed Dsg1 in pemphigus vulgaris, while suppression of Dsg1 function by anti-Dsg1 autoantibodies is perfectly compensated by richly expressed Dsg3 in pemphigus foliaceus. OBJECTIVES: We present five Japanese patients with pemphigus who deviate from this theory, i.e. all patients showed oral lesions (three also had cutaneous lesions) and reacted only with Dsg1, but not with Dsg3, by enzyme-linked immunosorbent assay. METHODS: To confirm whether the unique clinical phenotypes in our patients were due to a different immunological profile from that in classical pemphigus, we examined the reactivity of the patient sera by immunoprecipitation-immunoblotting analysis using five Dsg1/Dsg2 domain-swapped molecules. RESULTS: The sera of two patients who had only oral lesions tended to react with the extracellular (EC) 5 domain of Dsg1, the domain that is considered nonpathogenic in classical pemphigus foliaceus. Sera of three patients with mucocutaneous lesions reacted with EC1 domain or with both EC1 and EC2 domains of Dsg1, like classical pemphigus foliaceus. CONCLUSIONS: These results indicate that antigenic diversity of anti-Dsg1 antibodies in these patients may cause the unique oral mucosal and cutaneous lesions, although further studies are required to elucidate the pathomechanisms.