Abstract
IgG4-related disease is relatively recently defined systemic immune mediated condition. A serum IgG4 concentration > 1,35 g/L has been esta-blished as the cutoff value for the diagnosis of patients with IgG4-related disease.
The serum IgG4 elevation has low specificity but negative predictive value of a normal serum IgG4 concentration for the diagnosis is high. Diferential diagnosis encompasses many conditions, so that thorough clinicopathologic correlation is essential to making a diagnosis.
All IgG4 analyses performed in laboratory of Ústav imunologie 2. LF UK a FN Motol over two years period (2013-2015) were analyzed.
When IgG4 level was over 1,35 g/L, the patient's clinical observation was analyzed and the final diagnosis was recorded. Among 236 pacients only one was diagnosed IgG4-related disease - type 1 autoimmune pancreatitis.