[The spectrum of diseases associated with antineutrophil cytoplasmic antibodies]

Antineutrophil cytoplasmic antibodies (ANCA) are considered as a diagnostic marker of systemic vasculitis and rapidly progressing glomerulonephritis. They are frequently associated with other pathological conditions. The author's objective was to analyze a group of patients examined at the Department of Clinical Immunology of the First Medical Faculty Charles University in the course of one year and evaluation of the diagnostic asset of the ANCA examination.

ANCA was assessed in serum using the method of indirect immunofluorescence. In cases of p-ANCA the ELISA test was used to assess antimyeloperoxidase antibodies. Clinical data were evaluated on the basis of analysis of a questionnaire sent to doctors of patients where ANCA was detected. In 1992 1010 specimens were examined and in 115 ANCA was detected. This was the case in a group of 65 patients with the following diagnoses: systemic vasculitis 26x, systemic immunopathological diseases 12x, renal diseases 9x, inflammatory bowel diseases 7x, inflammatory eye diseases 6x, monoclonal paraproteinaemia 2x, other 4x. The patients had renal affections (45%), affections of the joints (20%), skin (18%), eyes (14%), lungs (12%), GIT (11%), ENT (9%), and nerves (9%). Type c in titres above 1:160 was always associated with the diagnosis of Wegener's granulomotosis, in other instances c- or x-types titres of 1:20 were involved. Antibodies against myeloperoxidase were detected in four instances.

The authors confirmed that c-ANCA in high concentrations are specific for the predominantly active form of Wegener's granulomatosis. The group of patients with p-ANCA is too small to generalize the diagnostic impact. Low ANCA concentrations are found in many other diseases. The importance of ANCA can be evaluated only in a clinical context and the importance of their presence must not be overestimated.