Antibody affinity enables early detection of type 1 diabetes in adults
Scientists at the Helmholtz Zentrum München have discovered a new diagnostic marker for determining LADA (latent autoimmune diabetes in adults), a special form of type 1 diabetes in adults. "Based on the affinity of the antibody reaction against the enzyme glutamate decarboxylase (GAD), patients with LADA can be distinguished from patients with non-autoimmune type 2 diabetes," reports the Helmholtz Zentrum München. Dr. Dr. Peter Achenbach, Stephanie Krause and Prof. Dr. Anette-Gabriele Ziegler published in the specialist magazine "Diabetes Care".
Similar to type 1 diabetes in childhood, type 1 diabetes in adulthood is based on an autoimmune reaction in which "the insulin-producing beta cells of the pancreas are destroyed by the body's own immune system", the scientists report. The LADA form of diabetes essentially differs from child-type 1 diabetes in that it is very slow. "The clinical manifestation takes place after the age of 30 and the patients do not need insulin therapy to control blood sugar at the beginning of the disease," explains the 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 simplifies the delimitation and enables early statements on the course of the disease.
International cooperation between scientists discovers diagnostic markers Together with national and international colleagues, the research team led by Dr. Anette-Gabriele Ziegler "studies to what extent the affinity of GAD antibodies, as a measure of the maturity of the immune response, improves the classification of diabetes in adulthood." The researchers also wanted to find out whether a subcutaneous (under the skin) "Vaccination with GAD affects antibody affinity." The scientists at 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 at TU Dresden and the Skane University Hospital in Sweden. Overall, they checked "the GAD antibody affinity in 46 LADA patients who had participated in a GAD vaccination study."
GAD antibody affinity as an indication of LADA According to the researchers, the study participants were injected with "GAD in different doses or a placebo preparation to induce tolerance of the immune system to the beta cells." Surprisingly, the scientists found that GAD Antibody affinity varied considerably before the start of treatment. Here, patients with high and low affinity could be distinguished. The researchers also found that patients with high GAD antibody affinity - "due to advanced autoimmune destruction of beta cells" - had low insulin production. Those affected often needed insulin therapy after a relatively short time. In contrast, significantly higher insulin production was observed in patients with low GAD affinity, which remained constant over a period of 30 months, the researchers write. Vaccination with GAD did not change the affinity for GAD antibodies.
Predictions can be made regarding the course of the disease Peter Achenbach shows the study results, "that GAD antibody affinity is a valuable new diagnostic marker in LADA patients." This enables predictions about the course of the disease and a corresponding adjustment of the therapy measures. "Antibody affinity should now also be taken into account in clinical studies in LADA patients," concluded Dr. Achenbach in the press release of the Helmholtz Zentrum München. (fp)
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