Evaluation of the pathogenicity of anti-desmoglein antibodies of pemphigus vulgaris patients using human organ culture assay.

Anti-desmoglein (anti-Dsg) antibodies are key players in the pathogenesis of pemphigus vulgaris (PV) disease. We aimed to evaluate the pathogenicity of anti-Dsg antibodies of PV patients using human organ culture assay and to assess the correlation between the pathogenicity and the disease score. In this cross-sectional study, sera from 37 PV patients were included. The organ culture acantholysis index (OCAI) was calculated as (width of blister/total width of the specimen) × 100. The sera were analyzed using Dsg ELISAs and ethylenediaminetetraacetic acid (EDTA) treated ELISAs. OCAI ranged from 0 to 100%, median = 50%. There was a moderate significant correlation between OCAI and the disease severity, r = 0.503, p = 0.002. There was a moderate significant correlation between OCAI and non-Ca2+-dependent anti-Dsg3 and anti-Dsg1 antibodies, p values were 0.01 and 0.021, respectively. The OCAI was assessed along the disease time course of four patients. The OCAI fluctuated parallel to the disease severity along the time course of the four patients. Human organ culture assay is an objective tool that detects the pathogenicity of anti-desmoglein antibodies. It can be used before stopping systemic steroids especially in patients in remission with high titer or if the Dsg ELISA is not available.

Influence of Nitrate and Nitrite on Thyroid Hormone Responsive and Stress-Associated Gene Expression in Cultured Rana catesbeiana Tadpole Tail Fin Tissue.

Nitrate and nitrite are common aqueous pollutants that are known to disrupt the thyroid axis. In amphibians, thyroid hormone (TH)-dependent metamorphosis is affected, although whether the effect is acceleration or deceleration of this developmental process varies from study to study. One mechanism of action of these nitrogenous compounds is through alteration of TH synthesis. However, direct target tissue effects on TH signaling are hypothesized. The present study uses the recently developed cultured tail fin biopsy (C-fin) assay to study possible direct tissue effects of nitrate and nitrite. Tail biopsies obtained from premetamorphic Rana catesbeiana tadpoles were exposed to 5 and 50 mg/L nitrate (NO(3)-N) and 0.5 and 5 mg/L nitrite (NO(2)-N) in the absence and presence of 10 nM T(3). Thyroid hormone receptor ß (TRß) and Rana larval keratin type I (RLKI), both of which are TH-responsive gene transcripts, were measured using quantitative real time polymerase chain reaction. To assess cellular stress which could affect TH signaling and metamorphosis, heat shock protein 30, and catalase (CAT) transcript levels were also measured. We found that nitrate and nitrite did not significantly change the level of any of the four transcripts tested. However, nitrate exposure significantly increased the heteroscedasticity in response of TRß and RLKI transcripts to T(3). Alteration in population variation in such a way could contribute to the previously observed alterations of metamorphosis in frog tadpoles, but may not represent a major mechanism of action.