Molecular diagnosis in autoimmune skin blistering conditions.

Blister formation in skin and mucous membranes results from a loss of cell-cell or cell-matrix adhesion and is a common outcome of pathological events in a variety of conditions, including autoimmune and genetic diseases, viral and bacterial infections, or injury by physical and chemical factors. Autoantibodies against structural components maintaining cell-cell and cell-matrix adhesion induce tissue damage in autoimmune blistering diseases. Detection of these autoantibodies either tissue-bound or circulating in serum is essential to diagnose the autoimmune nature of disease. Various immunofluorescence methods as well as molecular immunoassays, including enzyme-linked immunosorbent assay and immunoblotting, belong to the modern diagnostic algorithms for these disorders. There is still a considerable need to increase awareness of the rare autoimmune blistering diseases, which often show a severe, chronic-relapsing course, among physicians and the public. This review article describes the immunopathological features of autoimmune bullous diseases and the molecular immunoassays currently available for their diagnosis and monitoring.

Thyrotoxic myopathy in mice: accentuation by a creatine transport inhibitor.

To demonstrate the importance of creatine and phosphocreatine in skeletal muscle during periods of metabolic stress, thyrotoxicosis was induced in mice fed the creatine transport inhibitor, beta-guanidinopropionic acid (beta-GPA). Adding 2% of beta-GPA to the diet of normal mice inhibited weight gain and caused a 75% reduction of creatine and phosphocreatine concentrations in skeletal muscle. Addition of 0.25% or 2% of thyroid powder to the diet of normal mice was associated with hyperactivity, cardiomegaly, and a high mortality rate. Superimposing thyrotoxicosis on mice already depleted of creatine and phosphocreatine resulted in degeneration of muscle fibers. These results indicate that high concentrations of creatine and phosphocreatine are essential for the maintenance of muscle integrity during periods of metabolic stress.