Immunofluorescent patterns produced by antineutrophil cytoplasmic antibodies (ANCA) vary depending on neutrophil substrate and conjugate.

Background: The "International consensus statement on testing and reporting antineutrophil cytoplasmic antibodies (ANCA)" advocates screening by indirect immunofluorescence (IIF), but external quality assessment programmes often demonstrate different IIF patterns for a single serum.

Aim: To determine whether the variation in IIF patterns can be attributed solely to errors in interpretation.

Methods: This study compared the IIF patterns produced by four sera (two with cytoplasmic or C-ANCA; one with perinuclear or P-ANCA with myeloperoxidase (MPO) specificity; and one P-ANCA without MPO specificity) that were tested in 11 different laboratories.

Cell free serum interleukin-2 receptor levels after heart transplantation.

The aim of this study was to predict episodes of rejection or infection in heart transplant recipients by monitoring serum interleukin-2 receptor (IL-2R) levels, rather than by endomyocardial biopsy. The shedding of IL-2R from activated lymphocytes results in increased serum interleukin-2 levels and is probably a result of immune activation occurring in both rejection and infection processes. As a group, heart transplant recipients who had no rejection of infection had significantly increased serum IL-2R levels compared with healthy controls.

The role of alpha 1-antitrypsin deficiency in the pathogenesis of immune disorders.

The association between alpha 1-antitrypsin (alpha 1-AT) deficiency and a number of immune mediated diseases including rheumatoid arthritis, anterior uveitis, systemic lupus erythematosus, and asthma suggests that alpha 1-AT may be important not only as an anti-inflammatory protein but also as an immune regulator. That the relationship between decreased amounts of this inhibitor and these diseases is causal is suggested by both some of its physical properties and evidence indicating it is able to modulate immune function. alpha 1-Antitrypsin has a high plasma concentration, very broad range of inhibitory activity and is an acute phase reactant.