Granulomatosis with Polyangiitis (GPA, Wegener's Granulomatosis) may be associated with immune checkpoint inhibitor therapy.
Mechanism: potentiation of immune response, with emergence of autoimmunity
Agents that may be involved:
(1) CTLA4 antibody (anti-cytotoxic T-lymphocyte-associated protein 4 antibody): ipilimumab
(2) PD1 antibody (anti-programmed cell death 1 antibody): nivolumab, pembrolizumab
Clinical features:
(1) new onset of cutaneous vasculitis
(2) new onset of glomerulonephritis with dysmorphic erythrocytes and proteinuria
(3) arthralgias
(4) variable pulmonary infiltrate (diffuse and/or nodular)
(5) variable chronic sinusitis
(6) presence of PR3-ANCA in serum
(7) absence of GPA prior to the initiation of immune checkpoint inhibitor therapy
In the case of van den Brom et al the GPA appeared after initial ipilimumab therapy was followed by anti-PD1 therapy.