Monoclonal gammopathy of undetermined significance (MGUS) is not linked to as many serious diseases as previously thought, according to a study in the August issue of Mayo Clinic Proceedings (2009;84: 685–693). The finding may save patients from undergoing unnecessary workup and treatment, the researchers noted in a news release.
The condition has long been thought to be a precursor of serious disease, such as multiple myeloma, primary amyloidosis, and Waldenström macroglobulinemia, and some patients have been subjected to investigations and sometimes additional treatments as a precaution.
The study, supported in part by grants from the NIH and US Public Health Service, was a record review of 17,398 patients, all of whom were uniformly tested for the presence or absence of MGUS. Among the 17,398 samples tested, 605 cases of MGUS were identified. The researchers then looked at the incidence of more than 16,000 different diagnosis codes in those with MGUS and those without.
Fourteen real disease associations were found, while 61 disease associations with MGUS were determined to be likely coincidental. In addition to multiple myeloma, the associations deemed real include vertebral and hip fractures and osteoporosis.
“In addition to the article, we have made available on the journal Web site an appendix that has the raw data on all 16,062 hospital diagnosis codes, which we think will be valuable to other researchers in the field,” said senior author S. Vincent Rajkumar, MD, of the Department of Hematology. “These results have major implications both for confirmed associations and for 61 diseases in which the association with MGUS is likely coincidental.”