Anti-neutrophil cytoplasmic antibodies in chronic XXXX . Prevalence and diagnostic role.

@entity1 @entity3335 @entity66 @entity1333 @entity31 @entity29 @entity3921 @entity7134 @entity30
BACKGROUND: Anti-neutrophil cytoplasmic antibodies (ANCA), originally found to be associated with @entity1333 , have been reported to be present in chronic @entity29 . Most often the ANCA staining pattern is of the perinuclear type (p-ANCA), although nuclear and cytoplasmic stainings are seen. Single studies have shown some of the antibodies to react with lactoferrin or @entity3921 ; however, most studies have not been able to determine a main antigenic specificity. We studied the prevalence of ANCA in sera from 155 @entity1 with @entity31 , 128 @entity1 with @entity30 , and 51 @entity1 with @entity66 . The presence of ANCA was correlated to disease activity, extent, and age of onset of the diseases. Furthermore, we tried to characterize the antigen specificity by enzyme-linked immunosorbent assay (ELISA), using elastase, lactoferrin, @entity3335 , @entity7134 , and @entity3921 as antigens. METHODS: The sera were screened for ANCA by indirect immunofluorescence. Anti-nuclear antibodies (ANA) were analysed on HEp2 cells, and ELISA for specific ANCA was performed using the antigens mentioned. RESULTS: Most of the sera with positive immunofluorescence had the p-ANCA type of pattern. Seventy-eight of 155 (50.3%) of the @entity1 with @entity31 were ANCA-positive, compared with 31 of 128 (24.2%) of @entity1 with @entity30 (p < 0.001). However, in the subgroup with @entity30 , 16 of 44 (36.4%) were ANCA-positive. Only 4 of 51 @entity1 (7.7%) with @entity66 showed positive immunofluorescence (p < 0.001 compared with @entity31 ). Less than 10% of the samples were positive in the specific ELISA assays; thus other than the most well known granule proteins can be the target for ANCA in @entity31 . CONCLUSION: ANCA occur significantly more often in @entity31 than in @entity30 . However, the prevalence of ANCA is rather high in @entity30 . ANCA are thus of limited value in differentiating @entity30 from @entity31 . ANCA found in @entity29 are different from those associated with @entity1333 . The antigen(s) responsible remain to be determined.
