IgG4-related disease presenting with raised serum IgG2—real timeline of IgG4-RD?

IgG4-related disease (IgG4-RD) has rarely been reported as presenting with Adult Onset Asthma with Periorbital Xanthogranulomatosis (AAPOX).There is emerging evidence that serum IgG2 elevation may predate IgG4 elevation in both serum and tissues in patients with IgG4-RD.We present here the case of a 57 year old patient who developed AAPOX with no histological or serum evidence of IgG4 elevation, but an isolated raised serum IgG2 at onset.We give evidence that over time her clinical picture became more consistent with IgG4-RD, and that immunosuppression with Methotrexate may have attenuated the serological evolution of disease.We believe that further work is required to elucidate the true natural history of serological and histological progression in IgG4-RD as, at least in a sub-set of patients, isolated serum IgG2 elevation at presentation appears to be a precursor to disease.