[Pulmonary hyper IgG4 disease]

Hyper IgG4 syndrome (HIDI is a multisystem disease characterized by high levels of immunoglobulin IgG4 with possible involvement of the pancreas, lung and lymph nodes as well as other organs. It was first described in connection to autoimmune pancreatitis but since then, it became clear that it can also affect many other organs. The disease involves the thorax and lesions were described in the mediastinum, airways, lung parenchyma and pleura. it can simultaneously involve multiple organs or be localized in just one. HID can develop in part of the fibro-inflammatory diseases of the chest without clear etiology like pseudo tumors, mediastinal and pleural fibrosis or inflammation. HID was also found in connection with various diseases in the airways. The HID lesion is typically rich in plasma cells positive to IgG4, fibrosis and vascutitis. This disease is rare and until now there were almost no cases reported in Israel. High clinical suspicion can make the diagnosis and prescribe the right therapy. The prognosis is favorable if the diagnosis is made on time. New studies are needed to understand the connection and the importance of this pathology to the lungs and also the most suitable treatments available for it.