The Diagnostic Value Of Autoantibodies To CCL3for Type1Diabetes

Objective:Type1diabetes (TID) is a T cell-dependent tissue-specific autoimmune disease, characterized by the selective destruction of the β cells of the pancreatic islets of Langerhans. Recently, contradictory findings have been reported about the relationship of autoantibodies to CCL3and T1D, which need to be confirmed by more investigations in larger cohorts. The aim of our research was to investigate whether autoantibodies to CCL3are useful markers for T1D in a large cohort of Chinese patients.Subjects and Methods:1. We analyzed autoantibodies to CCL3, glutamic acid decarboxylase(GADA), insulinoma-associated protein-2(IA-2A), and zinc transporter-8(ZnT8A) by a radioimmunoprecipitation assay in290patients with TID (average age26.4yrs, range0.9-61yrs),200patients with type2diabetes(T2D, average age56.7yrs, range13-81yrs),210patients with other diseases(including77patients with autoimmune thyroiditis,32patients with systemic lupus erythematosus,64patients with rheumatoid arthritis and37patients with atopic dermatitis) and178healthy control subjects who were age-matched with the T1D patients. The patients with T1D, T2D and other diseases were selected from patients diagnosed at the Second Xiangya hospital of Central South University from Oct1999to Dec2010.2. We analyzed frequencies of autoantibodies to CCL3in290T1D patients with or without classical islet autoantibodies.3. We also analyzed Age, duration of disease, HbA1C, fasting C-peptide and postprandial C-peptide level, triglyceride (TG) and total cholesterol (TC) levels in T1D or T2D patients with positive autoantibodies to CCL3.Results:1. The frequencies of autoantibodies to CCL3in subjects with TID, T2D and healthy control subjects were similar [3.10%(9/290),2.50%(5/200), and0.56%(1/178), respectively,P-0.189].2. Autoantibodies to CCL3were not significantly different between T1D patients with or without GAD A, IA-2A, or ZnT8A antibodies(2.7%vs3.9%, P=0.725).3. Patients with systemic lupus erythematosus and rheumatoid arthritis showed higher positivity for autoantibodies to CCL3than healthy control subjects [15.6%(5/32) and12.5%(8/64) vs.0.56%(1/178), all P=0.000], and higher titer of autoantibodies to CCL3than T1D patients (median0.9633and0.4095vs.0.0873, P=0.012and P=0.034, respectively).4. No significant differences have been found between TID or T2D patients with positive autoantibodies to CCL3and those with negative ones in age, duration of disease, HbA1C, fasting C-peptide and postprandial C-peptide level, total cholesterol and triglyceride levels. Conclusions:Autoantibodies to CCL3are of low sensitivity and specificity for T1D and cannot be used in the diagnosis of T1D.