Rare case of interstitial nephritis in a young adult under IgG therapy.

Immunoglobulin replacement therapy is an important therapeutic approach used in different diseases, such as immunodeficiency diseases. We report a case of a 19-year-old female patient with suspected common variable immunodeficiency who started replacement therapy with IgG. During the follow-up, she developed interstitial nephritis and the subsequent workup excluded other diseases or triggers except IgG therapy.