Wegener granulomatosis: an analysis of 158 patients

ANCA and associated diseases: immunodiagnostic and pathogenetic aspects

The past decade has seen an explosion of data on the new group of autoantibodies known collectively as ANCA (anti-neutrophil cytoplasmic antibodies). ANCA are specific for granule proteins of granulocytes and monocytes and induce distinct fluorescence patterns, e.g. the cytoplasmic (classic) cANCA and the perinuclear pANCA. cANCA is induced by antibodies directed against Proteinase 3 (PR3; PR3-ANCA) in about 90% of all ANCA-positive sera, and pANCA is induced by antibodies against myeloperoxidase (MPO; MPO-ANCA) in about 40%. A further staining pattern, which does not have a clear cut association with a distinct granule protein, is sometimes seen in chronic inflammatory bowel diseases. PR3-ANCA are serological markers for Wegener's granulomatosis (WG) and MPO-ANCA are associated with certain subtypes of primary vasculitides. Evidence exists that both the autoantigen and ANCA participate in the pathogenesis of at least the group of 'ANCA-associated vasculitides'.

Limited prognostic value of changes in antineutrophil cytoplasmic antibody titers in patients with Wegener's granulomatosis

One hundred and six patients with Wegener's granulomatosis (WG) were studied for the presence of antineutrophil cytoplasmic antibodies (ANCA). In 53 patients serial ANCA determinations were obtained. C-ANCA positivity was a sensitive (88%) marker of active WG. However, changes in serial titers were temporally concordant with a change in disease status in only 55% of patients. Furthermore, a rise in c-ANCA titer preceded clinical exacerbation of disease in only 24% of patients who had been in remission or had low grade, smoldering disease. A rise in c-ANCA titer alone should not be considered a priori evidence of impending relapse, and does not justify modification of immunosuppressive therapy.

Treatment of antineutrophil cytoplasmic autoantibody-positive systemic vasculitis and glomerulonephritis with pooled intravenous gammaglobulin

Antineutrophil cytoplasmic autoantibody (ANCA) is considered a serological marker for disease activity in patients with ANCA(+) systemic vasculitis. Recently, ANCA has been implicated as a pathogenic antibody that may be associated with neutrophil degranulation and release of lytic enzymes. Since intravenous gammaglobulin (IVIG) is known to contain antiidiotypic antibodies to ANCA, which could decrease the activity of the later, we chose to treat two patients with symptomatic ANCA(+) systemic vasculitis and glomerulonephritis with high-dose IVIG. The first patient, a 66-year-old man, developed rapidly progressive renal failure despite treatment with intravenous (IV) cyclophosphamide. The second patient, a 14-year-old boy, had relapsed 3 months after cessation of treatment with prednisone and cyclophosphamide. Both patients improved dramatically after treatment with IVIG, with the former recovering renal function within 11 days of therapy. In both patients, a concomitant reduction in serum ANCA titers was also observed. The second patient is currently in a sustained remission 14 months after his last IVIG dose on no other medication. These cases provide clinical evidence that IVIG has therapeutic benefit in modifying the immune-mediated injury associated with ANCA(+) systemic vasculitis and glomerulonephritis. In addition, IVIG may provide an additional safe therapeutic option to clinicians treating patient's with ANCA(+) vasculitis and glomerulonephritis who are not responsive to or are experiencing toxicity from conventional therapy.

The treatment of Wegener's granulomatosis with glucocorticoids and methotrexate

OBJECTIVE

To identify alternatives to daily low-dose cyclophosphamide (CYC) in the treatment of Wegener's granulomatosis (WG).

METHODS

An open-label pilot study of weekly low-dose methotrexate (MTX) plus glucocorticoids (GC) for treatment of patients with WG was performed. Twenty-nine patients who did not have immediately life-threatening disease were included. Outcome was determined by clinical characteristics, pathologic findings, course of illness, laboratory and radiographic findings, and successful withdrawal of GC therapy.

RESULTS

Weekly administration of MTX (at a mean stable dosage of 20 mg) and GC resulted in marked improvement in 76% of the 29 patients. Remission was achieved in 69% of the patients, 7% improved but had intermittent smoldering disease that precluded total withdrawal of GC, and 17% had progressive disease within 2-6 months of starting the study treatment. Two patients who initially achieved remission later had relapses after GC was discontinued. Of those who remain in remission (mean followup time 14.5 months), 72% have not required GC for a mean period of 10 months.

CONCLUSION

Although standard therapy for WG (daily CYC and GC) has dramatically improved outcome in this often-fatal disease, treatment morbidity has led to attempts to identify effective interventions that have less toxicity. Weekly low-dose MTX was shown in this study to be a feasible alternative to CYC in patients whose illness was not immediately life-threatening or in whom prior CYC treatment was ineffective or produced serious toxicity. Although these results are preliminary, they are encouraging and justify further studies in which MTX, CYC, and other alternative therapeutic approaches are compared concurrently.