Neutrophil-specific autoantibodies in chronic inflammatory bowel diseases.

This review intends to highlight important differences between neutrophil-specific autoantibodies (NSA) typically found in chronic inflammatory bowel diseases (CIBD) and anti-neutrophil cytoplasm antibodies (ANCA) associated with primary systemic small vessel vasculitides (SSVV). Indirect immunofluorescence (IF) techniques alone cannot distinguish NSA from ANCA and special measures must be taken to separate these two autoantibody populations. Many autoantigens originating in all cell compartments may be targeted by NSA in CIBD, several of these being constituents of neutrophil nuclei. Apart from the use of NSA in the differential diagnosis between Crohn's disease (CD) and ulcerative colitis (UC), very limited clinical significance is ascribed to these antibodies in CIBD. Laboratory reports on NSA-positivity must be clearly distinguishable from reports on ANCA to help avoid clinical misinterpretation.