Barutçuoglu B.Başol G.Bozdemir A.E.Kirdök S.Habif S.Bayindir O.2019-10-262019-10-2620101300-02921300-0292https://doi.org/10.5336/medsci.2008-8234https://hdl.handle.net/11454/20149False-negative high density lipoprotein-cholesterol (HDL-C) detection is a remarkable condition in clinical laboratory practice. We report an 18-year-old female who admitted to transplantation division, with cirrhotic process of autoimmune hepatitis in which polyclonal hypergammaglobulinemia negatively interfered with HDL-C. The HDL-C and immunoglobulin G (IgG) levels were measured before and after liver transplantation. The patient had high IgG with polyclonal hypergammaglobulinemia and an undetectable HDL-C before transplantation. Falsely undetectable HDL-C levels were ruled out by two easy methods: sample dilution and back calculation based on Friedewald formula. This false negative value of HDL-C was also confirmed with lipoprotein electrophoresis. One must be careful in hyperimmunglobulinemic patients when using direct homogeneous HDL-C assay. © 2010 by Türkiye Klinikleri.tr10.5336/medsci.2008-8234info:eu-repo/semantics/openAccessAutoimmuneCholesterolHDLHepatitisHypergammaglobulinemiaArticle301392398Q4