Antibodies toneutrophil cytoplasmic antigens in Wegener's granulomatosis andother conditions

Theuseofserumantibodies toneutrophil cytoplasmic antigens (ANCA)asadiagnostic marker forWegener's granulomatosis andother formsofvasculitis hasbeenassessed. Although ANCA havebeendescribed byseveral groupstheprecise antigenic targets areunknown, and detection ofANCA still relies on anindirect immunofluorescence assaytechnique. Several different patterns offluorescence have been produced byusing serafromdifferent groupsofpatients, and insufficient information isavailable on thefrequency ofpositive results andofthepatterns of immunofluorescence obtained whenserum frompatients withvasculitis asa partofa generalised connective tissue disease isused. A study was carried outon serumfrom240patients, including 23 patients withWegener's granulomatosis, 12withmicroscopic polyarteritis, and30withvarious connective tissue diseases. Three patterns offluorescence wereobserved: bright coarsely granular cytoplasmic, bright non-granular cytoplasmic, andweakdiffuse cytoplasmic. Thebright, coarsely granular pattern was86%specific forWegener's granulomatosis inthis series andwasobserved in18 of23cases.Otherpatterns offluorescence were foundinvarious conditions andwere notof diagnostic value. Thetechnique issimple, inexpensive, rapid, andreproducible.