Objective: Interleukin 12 receptor beta 1 (IL-12Rβ1) deficiency is a primary immunodeficiency that exposes affected individuals to an augmented risk of intracellular pathogen-mediated infections. The paradoxical presence of autoimmune manifestations in immune-deficient patients has been recognized, but the basis of this phenomenon is unclear, with the role of frequent infections being a possible trigger to break tolerance. Our study aimed to analyze extensively a profile of autoantibodies in a clinically well-defined case series of patients with IL-12Rβ1 deficiency.Methods: Eight patients with IL-12Rβ1 deficiency referred to Children's Medical Center in Tunis, Tunisia, during 1995-2012 were enrolled in the study. Sixteen ageand gender-matched blood donors served as controls. Serum, liver-related autoantibodies immunoglobulin (Ig)G, IgM, IgA were tested by ELISA and by standard indirect immunofluorescence on Hep-2 cells.Results: We found a significant prevalence of liver autoantibodies in the study group.Regarding primary biliary cholangitis (PBC), two of eight patients were positive for MIT3 autoantibodies, both confirmed by immunofluorescence, and one patient was