Other testing that may be helpful includes Urinalysis, complete metabolic panel: Renal involvement Serum amylase and lipase, hemoglobin A1c, stool elastase: Pancreatic involvement Serum C3 and C4 complement levels: Low in IgG4-related tubulointerstitial nephritis and some other phenotypes Total IgG and total IgE levels An elevated total IgG level (hypergammaglobulinemia) or an elevated globulin to albumin ratio indicates the activation of antibody secreting cells that is typical of but not specific to IgG4-RD.