title: A comparative study of monoclonal gammopathies and immunoglobulin levels in Japanese and United States elderly.
abstract: OBJECTIVE
  To define the prevalence of monoclonal immunoglobulin (Ig) proteins and quantitative serum immunoglobulin levels in elderly Japanese in comparison with elderly Caucasians as possible factors related to the reported lower incidence of multiple myeloma in elderly Japanese than in elderly Caucasians.
  
  
  METHODS
  Survey study
  
  
  METHODS
  Community Center in Yokohama, Japan and Retirement Community in the United States.
  
  
  METHODS
  Convenience sample of community-dwelling elderly subjects (age 63-95) presenting for health screening examinations in each setting. Frozen serum samples were obtained from routine screening from 146 consecutive Japanese subjects and 111 US subjects.
  
  
  METHODS
  None
  
  
  METHODS
  Presence of monoclonal immunoglobulin protein determined by serum protein electrophoresis and immunofixation and quantitative Ig by laser nephelometry.
  
  
  RESULTS
  Four (2.7%) of the Japanese cohort had monoclonal gammopathies compared with 11 (10%) of the American cohort. Two of the monoclonal gammopathies were IgG Kappa and two were IgG Lambda. No cases of multiple monoclonal gammopathy were identified in the Japanese group, compared with 25% of the monoclonal gammopathies in the American group. The mean quantitative serum IgG level for the Japanese group was 1,685 +/- 520 mg/dL versus 1,118 +/- 402 mg/dL for the American group; mean quantitative IgA levels were 283 +/- 116 mg/dL versus 226 +/- 116 mg/dL (P < 0.001). Albumin levels were normal in both populations, suggesting that there was not an increase in occult inflammatory disorders in the Japanese population.
  
  
  CONCLUSIONS
  The low prevalence of monoclonal gammopathy in elderly Japanese is consistent with the reported lower frequency of multiple myeloma. The reason for the higher quantitative immunoglobulin levels in this population is unclear. Further cross-cultural investigation is warranted to explore the genetic influences on altered immune regulation with aging.
authors.affiliation: Geriatric Research, Education, and Clinical Center, VA Medical Center, Durham, North Carolina.
authors.forename: M
authors.initials: M
authors.lastname: Bowden
authors.forename: J
authors.initials: J
authors.lastname: Crawford
authors.forename: H J
authors.initials: HJ
authors.lastname: Cohen
authors.forename: O
authors.initials: O
authors.lastname: Noyama
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001797:Blood Protein Electrophoresis; D003431:Cross-Cultural Comparison; D006304:Health Status; D006306:Health Surveys; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood*; D007074:Immunoglobulin G / Q000097:blood*; D007075:Immunoglobulin M / Q000097:blood*; D007564:Japan / Q000453:epidemiology; D007834:Lasers; D008403:Mass Screening; D008875:Middle Aged; D008998:Monoclonal Gammopathy of Undetermined Significance / Q000097:blood / Q000453:epidemiology* / Q000235:genetics; D015999:Multivariate Analysis; D009391:Nephelometry and Turbidimetry; D015995:Prevalence; D016036:Seroepidemiologic Studies; D014481:United States / Q000453:epidemiology
chemical_list: D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007075:Immunoglobulin M