Anti-neutrophil antibody associated vasculitis in systemic sclerosis.

OBJECTIVES

To report 3 cases ANCA-associated vasculitis (AAV) that developed in patients suffering from systemic sclerosis (SSc) and to review previously reported cases.

METHODS

We describe 3 patients diagnosed with SSc who developed severe AAV that presented as crescentic glomerulonephritis (GN) and/or alveolar hemorrhage. A retrospective review of the literature was performed using the PubMed database.

RESULTS

The first patient presented with rapidly progressive renal failure and then with 2 episodes of massive alveolar hemorrhage. She was partially refractory to treatment with corticosteroids and cyclophosphamide but responded promptly to treatment with rituximab. The second patient suffered from 2 episodes of fulminant alveolar hemorrhage; the first responded to intravenous corticosteroids, but the second was fatal despite aggressive immune suppression with corticosteroids and cyclophosphamide. The third patient presented with a clinical picture compatible with scleroderma renal crisis (SRC) but was later diagnosed with crescentic GN and subsequently died from probable alveolar hemorrhage. Thirty-seven cases of AAV in SSc patients have been described in the English literature. Clinical manifestations include rapidly progressive GN, alveolar hemorrhage, limb ischemia, and vasculitic skin rash. In contrast to SRC that usually develops early in the course of SSc, ANCA-associated GN in SSc patients occurred later, after several years of illness. Hypertension, microangiopathic hemolytic anemia, and thrombocytopenia that are the hallmark of SRC were observed only in a minority of AAV cases. Almost all cases of AAV in SSc were positive for MPO-ANCA.

CONCLUSIONS

AAV in the setting of SSc is a diagnostic challenge. Differential diagnosis from SRC is crucial as treatment approach for these conditions completely differs. High doses of corticosteroids and immune suppression are advocated in severe AAV. In resistant cases, treatment with rituximab may be considered.