The prevalence of antibodies against desmoglein 1 in endemic pemphigus foliaceus in Brazil. Cooperative Group on Fogo Selvagem Research.

BACKGROUND: Pemphigus foliaceus is an autoimmune skin disease mediated by autoantibodies against desmoglein 1. The endemic form is thought to have an environmental cause. The Terena reservation of Limão Verde in Mato Grosso do Sul, Brazil, is a recently identified focus of the disease, with a prevalence of 3.4 percent in the population. We tested the hypothesis that normal subjects living in an endemic area have antibodies against desmoglein 1. METHODS: We used an enzyme-linked immunosorbent assay to detect antibodies against desmoglein 1 in serum samples from 60 patients with endemic pemphigus foliaceus (fogo selvagem) who lived in Limão Verde or elsewhere in Brazil, 372 normal subjects (without pemphigus foliaceus) from Limão Verde and surrounding locations, and 126 normal subjects from the United States and Japan. RESULTS: Antibodies against desmoglein 1 were detected in 59 of the 60 patients with fogo selvagem (98 percent) but in only 3 of the 126 normal subjects from the United States and Japan (2 percent). Antibodies were also detected in 51 of the 93 normal subjects from Limão Verde (55 percent) and in 54 of the 279 normal subjects from surrounding areas (19 percent). Serum samples obtained one to four years before the onset of disease were available for five patients; all five had antibodies in the initial serum samples, and the onset of disease was associated with a marked increase in antibody values. CONCLUSIONS: The prevalence of antibodies against desmoglein 1 is high among normal subjects living in an area among where fogo selvagem is endemic, and the onset of the disease is preceded by a sustained antibody response. These findings support the concept that the production of antibodies against desmoglein 1 is initiated by exposure to an unknown environmental agent.

Hyper-M-immunoglobulinemia in children with bronchial asthma.

Radial immunodiffusion was used to measure the concentrations of IgG, IgA, and IgM in the sera of 224 asthmatic children, ages 6 months to 14 years. IgM was greater than two standard deviations above age-matched normal values in 51% of these asthmatic subjects. Immunoglobulin profiles were repeated up to four years later in 29 individuals with elevated IgM and increased IgM synthesis was sustained in 14 of these asthmatic subjects. Serum IgE concentrations were elevated in 23 of 35 asthmatic patients. There was no statistical difference in mean IgE between asthmatic children with normal or increased IgM. The distribution of IgE in each group was similar. Only 10 of 224 subjects had an IgA concentration less than 2 SD below age-matched control subjects. The significance and possible mechanisms of hyper-M-immunoglobulinemia are discussed.