In the criteria, classifying patients with IgG4-RD is a three-step process that carefully assesses data from four domains, which must make sense in the context of IgG4-RD. The process includes synthesizing information from the patient's clinical presentation, blood test results or serology, radiological findings and the pathology data. Few other diseases require such careful synthesis of various information to get an accurate diagnosis, and at this time, there is no single diagnostic test for the disease.

The 2019 ACR/EULAR Classification Criteria for IgG4-Related Disease were validated in a large cohort of patients and demonstrated excellent test performances. Dr. Stone feels they should be a highly useful contribution to future investigations in this disease, and will ultimately help improve the lives of patients with IgG4-RD.

"IgG4-RD is a disease that tends to afflict middle-aged to elderly individuals and often affects and damages the pancreas severely, making glucocorticoids a suboptimal therapy for this condition," Dr. Stone says. "Clinical trials will help develop targeted therapies that spare toxicities from conventional treatments. Investigators need to have criteria like this to determine whether a patient should be classified as having IgG4-RD."

Dr. Stone is a professor of medicine for Harvard Medical School and the Edward A. Fox Chair in Medicine at Massachusetts General Hospital.