Measurement of Anti-GAD antibody by EIA and RIA Methods in Korean Diabetic patients: Study for pathogenesis of slowly progressive IDDM

Lee, Han Hyo; Shin, Young Goo; Kim, Hee Sun; Kim, Chang Young; Jeong, Yon Soo; Kim, Hong Seung; Park, Deok Woo; Yoon, Kap Jun; Chung, Choon Hee

Abstract

background: Sometimes it is difficult to discriminate between IDDM and NIDDM among adults with DM. Some NIDDM patients have autaantibodies and follow the course of IDDM, We call them as slowly progressive IDDM(SPII)DM). Since anti-GAD (Glutamic acid decarboxylase') Ab can be detected both before and for a long pe.riod after the diagnosis of DM it is helpful for the diagnosis of autoimmune diabetes.
METHODS
The subjects were 68 diabetic patients who were admitted at Wonju Christian Hospital from May 1994 to Feb 1996. We classified them as IDDM, NIDDM and SPIDDM. We analyzed the following: a studied basic clinical study, oral glucose tolerance test, HLA DR typing, IgM anti-viral Abs, ICA, IAA and nti-GAD Ab.
RESULTS
In measurement of anti-GAD Ab, IRMA was more sensitive than EIA. Anti-GAD Ab prevalence was significantly higher in IDDM patients than in NIDDM patients. By IRMA method, Anti-GAD titers showed significant correlation among VELISA, HEXT, IRMA and RSR methods(p<0.001).
CONCLUSION
As seen by the results above, the positivity of antiGAD Ab by EIA and RIA method was lower for Korean diabetic patients than for Caucasians. We suggest that the other mechanisms as well as autoimmunity may be involved in the pathogenesis of SPIDDM in Koreans. We need follow-up studies about the clinical and immunogenetic characteristics of these patients.