Although the standard deviations were high in all groups, our results are statistically significant in all relevant comparisons: when comparing changes in BPI-ANCA values in patients with or without EIGSS, patients with or without LTX and BPI-ANCA values before and after EIGSS and LTX. The non-operated group included more chronically infected patients than the EIGSS

group, and consequently, this group had higher BPI-ANCA levels, but those were unchanged over time. Based on experience from patients with granulomatosis with polyangiitis (Wegener’s) (GPA), where IgG ANCA is also associated with disease activity [21], it must be expected Metformin mw that the levels of BPI-ANCA may depend on the assay methodology [22]. At present, the assays available DNA Damage inhibitor for the detection of BPI-ANCA have not been standardized. As patients with CF have more positive IgA than IgG BPI-ANCA, it may be necessary to further investigate whether or not this difference is real and also whether or not different assays might be more sensitive. ANCA is a family

of autoantibodies directed at different components in the granules of the cytoplasm of human neutrophils. It is of interest that the presumed mechanism for BPI-ANCA production is a costimulation of dendritic cells with BPI complexed to P. aeruginosa surface antigens [9] and other Gram-negative bacteria, Venetoclax research buy whereas the presumed mechanisms for production of PR3-ANCA include molecular mimicry [23], a disrupted balance between the naturally occurring PR3-ANCA and its anti-idiotypic antibody [24], and epigenetic modifications leading to inappropriate expression of PR3 [25]. Another aspect is the possible pathogenic role of ANCA. In microscopic polyangiitis (MPA), ANCA is mainly directed against myeloperoxidase (MPO). MPO-ANCA and to a lesser extent Pr3-ANCA has been shown to activate TNF-primed neutrophils

[26]. Later, it has been possible to mimic MPA manifestations in experimental animals by infusing MPO-ANCA [27], and recently, a similar observation has been made by the same author, inducing GPA-like manifestations in mice with a humanized immune system using PR3-ANCA [28]. So far, a pathogenic role for BPI-ANCA has not been reported, but BPI-ANCA may also play a pathogenic role by neutralizing BPI, which is a potent inhibitor of Gram-negative bacteria [5, 8]. No standardized guidelines exist regarding the criteria for sinus surgery in patients with CF [10, 29]. Our results indicate that EIGSS with the intensive postoperative treatment regimen should be performed in selected CF patients with sinus infection. The possible long-term benefit of EIGSS in patients with CF has to await postoperative follow-up studies on the quality of life, frequencies of lung colonizations and the need for LTX.