IgG4 (Immunoglobulin G4) is rare subclass and constitutes to only 3-4% of human IgG in serum. It is a dynamic antibody which has unique biological ability to undergo Fab-arm exchange and limit immune complex formation. IgG4 acts as a blocking antibody in allergy which helps in inhibiting mast cell degranulation, but plays a deleterious role in malignant melanoma, by impeding IgG1-mediated anti-tumor immunity. The over expression of IgG4 is seen in inflammatory pseudotumor (IPT) and under expressed in inflammatory myofibroblastic tumor (IMT). There are an increased number of IgG4+ plasma cells in pulmonary nodular lymphoid hyperplasia (PNLH).
|Tissue Type/Cancer Type||
6 mL (RTU), 100 Tests – Automation – i6000, 1 mL(Conc.), 0.5 mL (Conc.), 160 tests – Xmatrx Elite, 50 tests – Xmatrx Elite, 5 slides – Xmatrx, 5 slides – Manual