ABSTRACT
Common variable immunodeficiency (CVID) is a heterogenous syndrome characterized by hypogammaglobulinemia, various immunologic abnormalities and recurrent bacterial infections. Associated immunologic abnormalities consists of various kinds of autoimmune diseases and lymphoproliferative disorders. The lymphoproliferative disorder take several forms, such as malignant lymphoma, atypical lymphoid hyperplasia, and beniegn lymphoid hyperplasia. Lymphocytic interstitial pneumonia (LIP), which is a kind of atypical lymphoid hyperplasia, develop in young age groups and has controversy on its clonality. We experienced a 14-year-old female patient with LIP and CVID. We analysed the third complementarity-determining region (CDR3) of the immunoglobulin heavy chain gene for clonality analysis. Clonality analysis of lung biopsy specimen revealed that 6 of 13 colony and 4 of 13 colony have identical sequences respectively. We speculate that one of these 2 lymphoid cell clone may develop into malignant lymphoma in the future.