Maintenance
Following a successful induction of remission, maintenance therapy might be given in some cases, for example when there is a high risk of relapse or in patients with organ-threatening manifestations. Common maintenance therapy is prednisolone 2.5–5 mg per day, or use of a steroid-sparing agent instead. Relapse
Relapses are common, and a previous history of relapse appears to be a strong predictor of future relapse. When relapse occurs while off therapy and there has been a prolonged disease remission following initial glucocorticoid induction, then the relapse can usually be managed successfully with a re-induction strategy using glucocorticoids. Introducing a steroid-sparing agent might also need to be considered for relapses; however, none has been tested in prospective, controlled studies, and evidence for their efficacy beyond that offered by concomitant glucocorticoid therapy is scarce.In one retrospective cohort study, baseline concentrations of serum IgG4, IgE and blood eosinophils were found to be independently predictive of relapse risk following treatment with rituximab with or without glucocorticoids; the higher the baseline values, the greater the relapse risk and the shorter the time to relapse. Other interventions
When organ involvement causes local mechanical problems, further organ-specific interventions may be necessary. For example, when a tumefactive lesion causes obstruction of the bile duct, it may be necessary to insert a biliary stent to allow the bile to drain freely. Similarly, ureteral or vascular stents, surgical resection or radiotherapy may be considered for various different presenting problems.
Symptoms are commonly attributed to other conditions and other diagnoses may have been made years before diagnosis, e.g. urinary symptoms in men attributed to common prostate conditions. Lesions may also be detected incidentally on radiological images, but can be easily misdiagnosed as malignancies.Reported cases do include some significant symptoms or findings however:

Individual organ manifestations
IgG4-RD can involve one or multiple sites in the body. With multiorgan involvement, the sites involved can be affected at the same time (synchronously) or at different unrelated periods (metachronously). Several different diseases that have been known for many years are now considered to be manifestations of IgG4-RD. These include: type 1 autoimmune pancreatitis, interstitial nephritis, Riedels thyroiditis, Mikuliczs disease, Küttners tumor, inflammatory pseudotumors (in various sites of the body), mediastinal fibrosis and some cases of retroperitoneal fibrosis. This is not a complete list, as IgG4-RD can involve any site in the body. Other affected sites, confirmed on histology to be manifestations of IgG4-RD, include:
heart; hard palate, esophagus, stomach, small intestine, rectum, adrenal gland, ovary, uterus, ureter, bladder, urachus, and synovium. Approximately 1/3 of cases exhibit increases in blood eosinophil counts, either eosinophilia or hypereosinophilia.Radiologic evidence suggestive of involvement of the superior vena cava and seminal vesicle has been reported in confirmed cases of IgG4-RD. Histology
Whatever area of the body is involved, the hallmark histopathological features of IgG4-RD are:
A dense lymphoplasmacytic (lymphocytes and plasma cells) infiltrate rich in IgG4-positive plasma cells. IgG4 immunostaining needs to be specifically requested and performed in order to detect IgG4-positive plasma cells.