Immune dysregulation syndromes (CTLA4 and LRBA deficiency) belong to the combined primary immunodeficiencies with defective tolerance due to lack of T regulatory lymphocytes function and resulting autoimmune complications. One of them is interstitial lymphocytic lung disease (ILLD), caused by pathologic bronchi-associated lymphoid tissue hyperplasia, progressive loss of lung function and decreased life expectancy. ILLD diagnosis is based on pathomorphological lung changes and radiologic symptoms. Targeted therapy with Abatacept in patients with immune dysregulation syndromes provides control of the autoimmune complications, including ILLD and is well tolerated. Here we demonstrate two cases of patients with immune dysregulation syndromes and ILLD treated with Abatacept.