The impact of intestinal resection on serum levels of anti-Saccharomyces cerevisiae antibodies (ASCA) in patients with Crohn's disease.

BACKGROUND: Antibodies to Saccharomyces cerevisiae (ASCA) are highly prevalent in sera of patients with Crohn's disease and have been proposed to identify subgroups of patients with a disabling disease course. AIM: To investigate the impact of intestinal resection on serum levels of ASCA in patients with Crohn's disease and the predictive value of ASCA levels on surgical recurrence. METHODS: Sera from 60 patients who underwent 'curative' intestinal resection due to stricturing and/or penetrating complications were collected preoperatively and during post-operative follow-up (week 2, months 4, 8 and 11 ± 1). Measurement of ASCA IgG and IgA isotypes were performed using ELISA. Re-operation rate was associated with ASCA status and serum levels. RESULTS: At baseline 44/60 (73%) of patients were rated as positive for ASCA IgG, 45/60 (75%) for ASCA IgA and 52/60 (87%) as positive for at least one of both. ASCA serum levels remained stable during first year from resection. After a median of 106 months 10 of 40 (25%) patients with long-term follow-up underwent one or more intestinal re-operations. Neither ASCA positivity nor absolute ASCA serum levels were predictive of surgical recurrence. CONCLUSIONS: Serum ASCA levels remain stable after curative intestinal resection in Crohn's disease. This indicates the persistence of both stimulus and immunological mechanism operative in the production of ASCA even after complete surgical resection of macroscopically inflamed intestinal tissue. After intestinal resection, neither ASCA positivity nor ASCA serum levels predict the risk of surgical recurrence during long-term follow-up.

Simultaneous determination of Fe(II) and Fe(III) in pharmaceutical formulations with chromogenic mixed reagent by using principal component artificial neural network and multivariate calibration.

The use of chemometric approaches for the simultaneous determination of Fe(II) and Fe(III) ions has been explored by means of a two component reagent. Mixed reagents of 1,10-phenanthroline and thiocyanate were used as a selective chromogenic system for speciation of Fe(II) and Fe(III). Although the complexes of Fe(II) and Fe(III) with mixed reagent show a spectral overlap, they have been simultaneously determined with chemometric approaches, such as principal component artificial neural network (PC-ANN), principal component regression (PCR) and partial least squares (PLS). A set of synthetic mixtures of Fe(II) and Fe(III) was evaluated and the results obtained by the applications of these chemometric approaches were discussed and compared. It was found that the PC-ANN and PLS methods afforded better precision relatively than its of PCR. PC-ANN and PLS methods were also applied satisfactorily in determination of Fe(II) and Fe(III) in pharmaceutical samples.

Evidence for a streptococcal superantigen-driven process in acute guttate psoriasis.

Recent studies have suggested that T cells play a critical role in the pathogenesis of psoriasis. Guttate psoriasis is a well-defined form of psoriasis frequently associated with streptococcal throat infection. This study tested the hypothesis that T cells in acute guttate psoriasis skin lesions may be activated by streptococcal superantigens. Peripheral blood as well as lesional and perilesional skin biopsies were analyzed for T cell receptor V beta repertoire using monoclonal antibodies against 10 different V beta families. Skin biopsies from all patients with acute guttate psoriasis, but not skin biopsies from patients with acute atopic dermatitis or inflammatory skin lesions induced in normal subjects with sodium lauryl sulfate, demonstrated selective accumulation of V beta 2+ T cells (P < 0.05). The expansion of V beta 2+ T cells occurred in both the CD4+ and the CD8+ T cell subsets. Sequence analysis of T cell receptor beta chain genes of V beta 2-expressing T cells from skin biopsies of patients with guttate psoriasis showed extensive junctional region diversity that is more compatible with a superantigen rather than a conventional (nominal) antigen-driven T cell response. All streptococcal isolates from patients with guttate psoriasis secreted streptococcal pyrogenic exotoxin C, a superantigen known to stimulate marked V beta 2+ T cell expansion. These data support the concept that acute guttate psoriasis is associated with superantigenic stimulation of T cells triggered by streptococcal superantigen(s).

Evidence for superantigen involvement in cardiovascular injury due to Kawasaki syndrome.

Kawasaki syndrome (KS), the major cause of acquired heart disease in children, is an acute multisystem vasculitis frequently associated with the development of myocarditis and coronary artery abnormalities. Despite the widely held belief that KS is an infectious disease, its etiology has remained elusive. Recently, we and others have reported the selective expansion of V beta 2+ T cells in the peripheral blood of most patients in the acute, but not in the convalescent, phase of KS. These data were consistent with the concept that this illness is triggered by a bacterial superantigen. We report here that a patient who died of acute KS had selective expansion of V beta 2+ T cells in her myocardium and coronary artery. Sequence analysis of TCR beta-chain genes of V beta 2+ T cells from the myocardium showed extensive junctional region diversity. These observations, along with the demonstration of V beta 2 expansion in both the CD4+ and CD8+ T cell subsets, support the concept that the activation of infiltrating V beta 2+ T cells are involved in the cardiovascular damage associated with KS.