To the Editor:
Immunoglobulin (Ig) G4-related disease is a relatively new fibroinflammatory systemic condition of unknown etiology. It is usually associated with elevated serum IgG4 concentrations1. Among the disease-initiating mechanisms, host genetic factors are thought to be important, but there is a paucity of genetic studies and to date only a few probable susceptibility factors have been described1. Our aim is to spur further genetic research by postulating Ig GM allotypes — highly polymorphic hereditary antigenic determinants expressed on γ chains — as possible risk factors for IgG4-related disease. GM (IgG marker) allotypes are encoded by 3 very closely linked genes on chromosome 14q32. They are localized on the …
Address correspondence to Dr. J.P. Pandey, Department of Microbiology and Immunology, Medical University of South Carolina, Charleston, SC 29425, USA. E-mail: pandeyj{at}musc.edu