Objectives: The study represents a complex report on diagnostic and pathogenic significance of antineutrophil cytoplasmic autoantibodies (ANCA). Our report is founded on the results of our clinical and experimental studies.
Methods: ANCA was examined by indirect immunofluorescence, or ELISA-anti MPO. The data for evaluation of diagnostic ANCA associations were gained by means of questionnaires. The experimental part involved examination of the impact of sera containing ANCA and monoclonal antibodies (MoAb) against proteinase 3 and control MoaB specific for neutrophils.
Results: Within the course of 1 year we have examined 1010 samples, ANCA was found in 65 patients: 26 cases of systemic vasculitis, 12 cases of other autoimmune diseases, 9 cases of isolated glomerulonephritis, 7 cases of inflammatory intestinal diseases, 6 cases of ophthalmic inflammatory diseases, and 6 cases of other diseases. Vasculitis of small vessels found in our group of patients are concomitted by ANCA positivity in 90% (Wegener's granulomatosis 15/16, Churg--Strauss's syndrome 3/5, MPA 9/9), vasculitis of medium vessels 12% (classical polyarteritis nodosa 1/2, Kawasaki disease 0/2, Henoch--Schönlein's purpura 0/4, Takayasu's arteritis 1/4). The ANCA-containing sera inhibit the candidacidal activity by 65% in average. THe inhibitory impact is yielded by anti-proteinase MoAb, in contrast to the control MoAb.
Conclusion: c-ANCA in high concentration is specific for active form of Wegener's granulomatosis, other types of ANCA in low titres are not of diagnostic value for vasculitis. ANCA is concomitted especially by small vessels vasculitis. The proved inhibition of microbicidal PMN activity by ANCA can participate in some clinical signs of immunodeficiencies in vasculitis. (Tab. 5, Ref. 18.).