Vasculitis, neutrophilic dermatoses and related disorders

This chapter contains sections titled: Vasculitis; Other vasculitides and mimics of vasculitis; Behçet's disease; Neutrophilic dermatoses; References

Indirect immunofluorescence (IIF) of normal washed peripheral blood cells to demonstrate antineutrophil cytoplasmic antibodies (ANCA)

Background—The "International consensus document on testing and reporting of antineutrophil cytoplasmic antibodies (ANCA)" requires all sera to be examined by indirect immunofluorescence (IIF). However, commercial neutrophil slides are expensive, fluorescence patterns can be difficult to interpret, and coincidental antinuclear antibodies (ANA) cannot be demonstrated; in addition, in house cytospin neutrophil preparations are time consuming to prepare and deteriorate with time. Aims—To compare the IIF demonstration of ANCA, using washed peripheral blood cell smears, with commercial neutrophil preparations and with ANCA positivity as demonstrated by enzyme linked immunosorbent assay (ELISA). Methods—Serum fluorescence positivity, pattern, and intensity using washed peripheral blood cell smears were compared with the results obtained using commercial neutrophil slides (INOVA). Fluorescence positivity, pattern, and intensity of 500 sera from consecutive patients with suspected vasculitis tested with washed peripheral blood cells were compared with binding in ELISAs for proteinase 3 (PR3) and myeloperoxidase (MPO). Results—IIF of washed peripheral blood cell smears detected seven of eight sera with cytoplasmic fluorescence (C-ANCA), and 11 of 12 sera with perinuclear fluorescence (P-ANCA) demonstrated using commercial slides. The two sera that were negative by IIF were also negative in the ELISAs for both PR3-ANCA and MPO-ANCA. Of the 500 sera examined, there were 35 (7%) with C-ANCA, 65 (13%) with P-ANCA, and eight (2%) IIF negative sera that were positive by either ELISA. There was a strong correlation between C-ANCA fluorescence and PR3-ANCA values (p < 0.0001), and a moderate to strong correlation between P-ANCA fluorescence and MPO-ANCA values (p < 0.001) when ANCA fluorescence was demonstrated with washed peripheral blood cell smears. Conclusions—Washed peripheral blood cells are a convenient and useful low cost alternative to commercial or cytospin neutrophil preparations for the IIF demonstration of ANCA. Key Words: antineutrophil cytoplasmic antibodies • autoantibodies • indirect immunofluorescenc

Skewed Fc Glycosylation Profiles of Anti-proteinase 3 Immunoglobulin G1 Autoantibodies from Granulomatosis with Polyangiitis Patients Show Low Levels of Bisection, Galactosylation, and Sialylation

Proteomic

Glomerulonephritis associated with antibodies to neutrophil cytoplasm and glomerular basement membrane.

The prognosis for recovery of renal function of oligoanuric patients with anti-glomerular basement membrane disease is generally regarded as poor. Five patients are reported with dialysis-dependent renal failure in whom antibodies were present simultaneously both to neutrophil cytoplasm and glomerular basement membrane all of whom responded, at least initially, to immunosuppressive therapy and plasma exchange. Two of the 5 remain in clinical and immunological remission at 25 and 51 months of follow-up. We suggest that reversal of dialysis-dependent renal failure may be possible in some patients who display this dual antibody positivity