Prevalence of monoclonal gammopathy of undetermined significance.
BACKGROUND
The prevalence of monoclonal gammopathy of undetermined significance (MGUS), a premalignant plasma-cell disorder, among persons 50 years of age or older has not been accurately determined. We used sensitive laboratory techniques to ascertain the prevalence of MGUS in a large population in a well-defined geographic area.


METHODS
We identified all living residents of Olmsted County, Minnesota, as of January 1, 1995. We obtained serum that remained after the performance of routine clinical tests at Mayo Clinic or asked subjects for whom such serum was unavailable to provide a sample. Agarose-gel electrophoresis was performed on all serum samples, and any serum sample with a discrete band of monoclonal protein or thought to have a localized band was subjected to immunofixation.


RESULTS
Serum samples were obtained from 21,463 of the 28,038 enumerated residents 50 years of age or older (76.6 percent). MGUS was identified in 694 (3.2 percent) of these persons. Age-adjusted rates were higher in men than in women (4.0 percent vs. 2.7 percent, P<0.001). The prevalence of MGUS was 5.3 percent among persons 70 years of age or older and 7.5 percent among those 85 years of age or older. The concentration of monoclonal immunoglobulin was less than 1.0 g per deciliter in 63.5 percent and at least 2.0 g per deciliter in only 4.5 percent of 694 persons. The concentration of uninvolved immunoglobulins was reduced in 27.7 percent of 447 persons tested, and 21.5 percent of 79 tested had a monoclonal urinary light chain.


CONCLUSIONS
Among residents of Olmsted County, Minnesota, MGUS was found in 3.2 percent of persons 50 years of age or older and 5.3 percent of persons 70 years of age or older.
Kyle
Robert A
RA
Division of Hematology, Mayo Clinic, Rochester, Minn 55905, USA. kyle.robert@mayo.edu
Therneau
Terry M
TM
Rajkumar
S Vincent
SV
Larson
Dirk R
DR
Plevak
Matthew F
MF
Offord
Janice R
JR
Dispenzieri
Angela
A
Katzmann
Jerry A
JA
Melton
L Joseph
LJ
D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D008297:Male; D008875:Middle Aged; D008910:Minnesota / Q000453:epidemiology; D010265:Paraproteinemias / Q000097:blood / Q000453:epidemiology*; D015995:Prevalence; D017678:Sex Distribution
D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007075:Immunoglobulin M