Anti-neutrophil cytoplasmic antibodies (ANCA) specific for one or several antigens: useful markers for subtypes of ulcerative colitis and associated primary sclerosing cholangitis.

BACKGROUND

Dysregulation of antimicrobial response may trigger inflammatory bowel diseases (IBD). This study analyzed specificity of anti-neutrophil cytoplasmic antibodies (ANCA) in IBD patients and its clinical significance.

METHODS

Data from 52 ulcerative colitis (UC) patients with 32 Crohn's disease (CD) patients were compared. Primary sclerosing cholangitis (PSC) was present in 12/84 patients. ANCA, ANA and anti-smooth muscle antibodies (ASMA) were detected by IIF. ANCA were tested by ELISA for proteinase 3 (PR3), myeloperoxidase, bactericidal/permeability increasing protein, elastase, cathepsin G, lysozyme and lactoferrin.

RESULTS

pANCA were more frequently present in UC than in CD patients (p<0.001). ANCA titer correlated with the disease activity only in UC patients (p<0.05). UC patients more frequently had two or more ANCA specificities compared to CD patients (p<0.01). Multi-specific ANCA in medium and/or high concentrations were associated with long-lasting (p<0.05) and left-sided UC (p<0.001). Multi-specific ANCA with ANA and ASMA had sensitivity of 67% for PSC.

CONCLUSIONS

Higher concentrations of multi-specific ANCA in long-lasting, left-sided UC suggest an influence of bacterial stimulation on the break of tolerance. Multi-specific ANCA with ANA and ASMA could be markers for PSC. ANCA specific to several antigens may worsen inflammation by reducing antimicrobial capacity of neutrophil proteases and cationic proteins.