Determine diabetes by affinity of the antibodies

Affinity of antibodies allows early identification of type 1 diabetes in adults

03/10/2014

Scientists at the Helmholtz Zentrum München have discovered a new diagnostic marker for the determination of LADA (latent autoimmune diabetes in adults), a special type of adult type 1 diabetes. „Based on the affinity of the antibody reaction against the enzyme glutamate decarboxylase (GAD), patients with LADA can be differentiated from patients with non-autoimmune type 2 diabetes“, reports the Helmholtz Zentrum München. Your findings have Dr. Peter Achenbach, Stephanie Krause and Prof. Dr. med. Anette-Gabriele Ziegler in the trade magazine „Diabetes Care“ released.

Type 1 diabetes in adulthood, like that of childhood type 1 diabetes, is based on an autoimmune reaction in which: „The insulin-producing beta cells of the pancreas are destroyed by the body's immune system“ become, the scientists report. The LADA form of diabetes is characterized by a very slow course of childhood type 1 diabetes. „The clinical manifestation occurs after the age of 30 and the patients do not need any insulin therapy for the blood sugar control at the beginning of the disease“, explains Helmholtz Zentrum München in its current press release. Due to the special course, the distinction between LADA and type 2 diabetes is often difficult. However, the scientists have now identified a marker that significantly facilitates the delimitation and allows early statements on the course of the disease.

International cooperation of scientists discovers diagnostic markers
Together with national and international colleagues, the research team has Peter Achenbach, Stephanie Krause and Prof. Dr. med. Anette-Gabriele Ziegler „investigated how the affinity of GAD antibodies, as a measure of the maturity of the immune response, improves the classification of diabetes in adulthood.“ In addition, the researchers wanted to find out if a subcutaneous (under the skin) „Vaccination with GAD affects antibody affinity.“ The scientists of the Institute for Diabetes Research at Helmholtz Zentrum München were supported by experts from the German Center for Diabetes Research (DZD), the Center for Regenerative Therapies of the TU Dresden and the Skane University Hospital in Sweden. Overall, they checked „GAD antibody affinity in 46 LADA patients who had participated in a GAD vaccine study.“

GAD antibody affinity as an indication of LADA
According to the researchers, the study participants received an injection of „GAD in different doses or a placebo preparation to induce a tolerance of the immune system against the beta cells.“ Surprisingly, the scientists found that the GAD antibody affinity already varied significantly before the start of treatment. Here, patients with high and low affinity could be distinguished. Furthermore, the researchers found that patients with high GAD antibody affinity - „due to an advanced autoimmune destruction of beta cells“ - had a low insulin production. Those affected often needed insulin therapy after a relatively short time. In contrast, patients with low GAD affinity had significantly higher levels of insulin production, which remained constant over a 30-month period, the researchers write. By GAD vaccination, the GAD antibody affinity had not changed.

Predictions on the course of the disease possible
According to study leader Dr. Peter Achenbach show the study results, „GAD antibody affinity is a valuable new diagnostic marker in LADA patients.“ This allows predictions about the course of the disease and a corresponding adaptation of the therapeutic measures. „Antibody affinity should now also be considered in clinical trials in LADA patients“, so the conclusion of Dr. Achenbach in the press release of Helmholtz Zentrum München. (Fp)