IgG4-Related Disease (IgG4-RD) is a systemic inflammatory disorder with potential to affect almost every organ [1]. The diagnosis of IgG4-RD is primarily based upon characteristic histological findings combined with clinical and biochemical results. Elevated serum IgG4 levels (sIgG4) can be seen in up to 5% of the normal population [2]. IgG4 elevation is not regarded as an exclusive feature of IgG4-RD but is seen in many other disorders, mostly of a chronic inflammatory nature [3–6]. Our retrospective study aims to determine the diverse diagnostic entities associated with elevated sIgG4.
