Immunological and Metabolic Studies on Type 1 Diabetes Mellitus

Immune checkpoint inhibitor (ICI)-related type 1 diabetes mellitus (T1DM) is a severe immune-related adverse event (irAE), occurring in < 1% of cases. ICI-related T1DM typically progresses more rapidly than conventional acute-onset T1DM, but is slower than conventional fulminant T1DM, suggesting different processes of onset and progression. Positivity rates for glutamic acid decarboxylase (GAD) antibodies differ, with ICI-related T1DM showing a lower positivity rate than conventional acute-onset T1DM. However, no detailed follow-up studies have examined the GAD antibody levels before and after the onset of ICI-related T1DM. We report the case of a 58-year-old Japanese man with type 2 diabetes mellitus diagnosed with renal carcinoma and multiple lung metastases. Chemotherapy with pembrolizumab (an anti-programmed death-1 antibody) was initiated. On the first day of treatment, the patient's insulin secretion capacity was preserved, and GAD antibodies were negative. Thirty-four days after chemotherapy initiation, the patient developed diabetic ketoacidosis and was diagnosed with ICI-related T1DM. Interestingly, GAD antibodies became positive (17.7 U/mL) approximately one month after the initial ICI administration. Subsequently, GAD antibody levels declined rapidly, with negative conversion occurring in only 205days (approximately 6.5months). To the best of our knowledge, this is the first reported case of closely monitoring GAD antibody dynamics before and after the onset of ICI-related T1DM. Here, the dynamics of the GAD antibodies were clearly distinct from those in conventional acute-onset T1DM. This case report may provide valuable insights into the differences between the autoimmune responses of ICI-related and conventional T1DM in their disease onset and progression.

Type 1 diabetes mellitus (T1DM) is frequently associated with other autoimmune disorders that are characterized by the presence of organ-specific autoantibodies. Autoimmune thyroid disease (AIT) is the most frequent autoimmune disorder associated with T1DM. Thyroid peroxidase antibodies (TPOAb) serve as a marker for diagnosing AIT. Prior research indicates that thyroid dysfunction can negatively impact linear growth and glycemic control in subjects with T1DM. The present study was done to determine the impact of thyroid autoimmunity on the clinical and biochemical characteristics of patients with newly diagnosed T1DM. In this single-center, hospital-based, observational cross-sectional study, we enrolled 70 patients with newly diagnosed T1DM ≤18 years of age. Type 1 diabetes mellitus was diagnosed based on the acute onset of osmotic symptoms with or without diabetic ketoacidosis (DKA), severe hyperglycemia (blood glucose >13.9 mmol/l (>250 mg/dl)), and insulin requirement from the onset of diabetes. Secondary diabetes, pancreatic diabetes (Type 3c), and maturity-onset diabetes of the young (MODY) were excluded. Participants were screened for AIT disease using TPOAb testing. Based on the presence or absence of TPOAb, the participants were categorized into two groups: Group A comprised individuals with T1DM who tested positive for TPOAb, while Group B consisted of those who tested negative for TPOAb. Out of 70 patients, 41.4% were girls and 58.6% were boys, with a mean age of 9.8±4.4 years. The prevalence of TPOAb among the cohort was 18.6%. A significant majority of patients (71.4%), presented with DKA. Group A showed significantly lower mean height standard deviation scores (SDS) compared to Group B (-0.3±0.6 vs. -0.8±0.5, p = 0.004), but no differences in weight SDS or BMI SDS. Hemoglobin A1C (HbA1c) levels, C-peptide levels, and frequency of DKA did not differ between groups. Group A had higher mean thyroid-stimulating hormone (TSH) levels (4.8±3.7 µU/ml vs. 2.6±1.5 µU/ml, p = 0.001) and a greater proportion of patients with TSH levels above the upper limit of normal compared to Group B (38.4% vs. 7.1%, p = 0.008). Additionally, Group A exhibited a higher frequency of glutamic acid decarboxylase antibody (GADA) positivity compared to Group B (46.1% vs. 17.5%, p = 0.04). Patients positive for TPOAb exhibited significantly lower height SDS compared to TPOAb-negative patients. Additionally, T1DM patients with TPOAb positivity showed an increased frequency of GADA compared to those without TPOAb. However, no significant differences were found in HbA1c levels, C-peptide levels, or hematological parameters between TPOAb-positive and TPOAb-negative patients. These findings emphasize the impact of TPOAb on growth parameters in T1DM and advocate for routine screening of TPOAb in all T1DM patients, starting at the time of diabetes diagnosis.

Global diabetes mellitus (DM) prevalence is 425 million cases, 16 million of which emanate from Africa, and 458,900 from Kenya. The prevalence is expected to rise by 48% and 156% globally and in Africa by 2045 respectively. The disease complications are severe and increase the risk of death, with one death reported every eight seconds across the world. The financial implications are adverse, with $825 billion spent globally and $3.3 billion in Africa. In Kenya, $234 is currently spent on each diagnosed case of DM. Of the cost-effective interventions, the dietary intervention has been shown to be the most effective. Despite dietary practices being effective in the management of the disease, DM still represents a fundamental public health challenge in Kenya. Against this backdrop, it was reasonable to determine the type 2 diabetes mellitus (T2DM) patients’ dietary practices in order to develop an effective intervention strategy. This study adopted a descriptive cross-sectional study design. Fishers’ formula, was used to determine the sample size. Pretest was carried out at Naivasha Hospital where 10% of the respondents participated. Data were analyzed using SPSS version 25 and Nutri-survey. Statistical parameters used were Mean, standard deviation (SD), Percentages, and Chi-square. All research and ethical approvals and permits were obtained before the commencement of the study. About 262(96%) T2DM patients participated in the study. The majority were male (58.8%), aged 41-50 years (35.9%), married (79.8%), and had secondary education (42.7%). The main source of income was business (31.7%), they earned a household income of between KES 10001-20000; (31.3%), and had a family history of DM 59.9%. Starches (40.3%) and cooking oil (96.9%) were consumed daily. Most participants (71.8%) had a high dietary diversity score (DDS). Most participants exceeded their adequacy levels for energy, carbohydrates, and proteins. Furthermore, adequacy levels for fats and fiber were low. Most respondents had three meals (55.3%) per day. About (48.1%) of the respondents’ RBS was &gt;11.0 mmol/l. Household income and DDS (P≤0.018) had a significant correlation. On the other hand, respondents' RBS had a significant association with carbohydrate (P≤0.034) and Fiber consumption (P≤0.016). Type 2 diabetes mellitus patients consume a highly diverse diet with carbohydrates and fats being the most consumed nutrients. Adequacy levels for fiber were poor. The patients had poor glycemic control. Household income for most of the patients with T2DM was a predictor of dietary diversity while; carbohydrate and fiber intake correlated with the patients’ random blood sugar (RBS) levels. More emphasis should be placed on the quantity of the macronutrients consumed by encouraging the patients to consume a moderate amount of carbohydrates and proteins, but increase their consumption of a fiber-rich diet; this is beneficial in glycemic control.

Type 1 diabetes mellitus (T1DM) is an increasingly encountered chronic illness in Saudi Arabia. It is known to have an immune-mediated pathogenesis, which results in the loss of insulin-secreting β-cells responsible for maintaining normal blood glucose levels. The three main autoantibodies identified to play a role in the pathogenesis are islet cell antibodies (ICA), insulin autoantibodies (IAA) and glutamic acid decarboxylase antibodies (GAD). This study aims to determine at what age during childhood the autoantibodies ICA, IAA and GAD are most prevalent, and identify any correlation between their presence and the severity of the initial clinical presentation. Medical records of children diagnosed with T1DM in Riyadh in 2000–2007 were reviewed, and a total of 98 patients were included in the study (age range: 1–12 years, mean: 6.6 years, equal numbers by gender), of which 49% presented with diabetic ketoacidosis (DKA). Results showed that 67% were positive for ICA, 36% for IAA and 84.4% for GAD. The presence of ICA was predominant in children aged under six years. The presence of ICA and GAD in the absence of IAA was associated with more severe clinical presentation.

Disclosure: S. Htoo: None. S. Kalik: None. A. Busta: None. Introduction: Stiff-Person Syndrome (SPS) is a rare autoimmune neurological disorder that is characterized by muscle stiffness and muscle spasms. The estimated prevalence of SPS in the general population is 1 to 2 cases per million. Autoimmune antibodies such as anti-Glutamic acid decarboxylase (GAD) target y-aminobutyric acid (GABA) neurotransmitters, resulting in halting of inhibitory pathways that impair the relaxatory mechanisms of the muscles. Literature has shown few case reports of type 1 Diabetes Mellitus (T1DM) and SPS, however, concomitant occurrence of Latent Autoimmune Diabetes in Adult (LADA) and SPS remains rare. Case: A 39-year-old woman was evaluated for intermittent paresthesia, generalized stiffness in extremities, and episodic spasms of distal muscles. Findings were normal for cranial nerve exam, sensory and motor exam, reflexes and coordination. She had a medical history of latent autoimmune diabetes in adults (LADA), which was discovered during pregnancy 6 years prior. Although initially thought to be gestational diabetes, her insulin requirement remained elevated after delivery, and she had positive GAD antibodies with barely detectable c-peptide level. Her medications included once nightly insulin glargine and subcutaneous semaglutide. She was evaluated for secondary causes of polyneuropathy. Biochemical work-up was normal for thyroid disorders, vitamin deficiencies, other autoimmune and inflammatory disorders. Other laboratory investigations revealed hemoglobin a1c 5.0, serum Glutamic Acid Decarboxylase (GAD) antibody of 38.3 nmol/L (range ≤ 0.02 nmol/L), cerebrospinal (CSF) GAD antibody of 0.39nmol/L (range ≤ 0.02 nmol/L), and c-peptide 0.8 ng/mL (range 1.1 - 4.4 ng/mL). MRI brain and MRI spine were normal. Electromyography (EMG) investigation revealed an abnormal relaxation of agonist and antagonist muscles. A diagnosis of Stiff-person syndrome (SPS) was supported by classic neurological findings, positive GAD antibody on serum and CSF, and characteristics on EMG study. She was treated with 5 days of 1g methylprednisolone and immunoglobulin therapy with observance of mild clinical improvement. Discussion: About 43% of patients with SPS are shown to have T1DM. Although consistent correlation has not been established between the serum anti-GAD titers and disease severity, past cases showed titers levels to be 50-100 times higher than normal in patients with SPS and T1DM. Our patient had LADA serum anti-GAD titer 38.3 nmol/L and she had prominent symptoms of SPS. This demonstrates there could be various levels of severity in SPS. Therefore, we propose larger sale studies are needed to categorize the severity of SPS, to better understand relationship between spectrum of autoimmune diabetes conditions and SPS, and to develop screening guidelines for SPS in patients with both LADA and T1DM. Presentation: Monday, July 14, 2025

Serum electrolytes levels in patients with type 2 diabetes mellitus: a cross-sectional study

Type 1 diabetes mellitus (T1DM) is frequently associated with autoimmune thyroid diseases (AITD), but little is known about the risk of AITD in latent autoimmune diabetes in adults (LADA). We evaluated the genetic and immunological factors involved in the development of thyroid autoimmunity in patients with LADA and T1DM. One hundred and ninety T1DM and 135 LADA patients were recruited in the study. Thyroid peroxidase antibody (TPOAb), thyroglobulin antibody (TGAb), glutamic acid decarboxylase antibody (GADA) and thyroid function were measured. The cytotoxic-lymphocyte-associated antigen-4 (CTLA-4) +49A/G and CT60 polymorphisms and the human leucocyte antigen (HLA)-DQA1-DQB1 genotype were determined. The prevalence of thyroid antibodies (TGAb and/or TPOAb) and thyroid dysfunction was 27·4% and 9·5% in patients with T1DM, and 21·5% and 11·1% in patients with LADA. Thyroid-antibody-positive T1DM patients had higher frequencies of GADA and HLA-DQA1*03-DQB1*0401 haplotypes than thyroid-antibody negatives (P < 0·05). Thyroid-antibody-positive LADA patients had higher GADA titre, lower C-peptide levels and higher frequencies of HLA-DQA1*03-DQB1*0401 haplotypes (P < 0·05). The CTLA-4 +49A/G and CT60 polymorphism was associated with T1DM complicated with thyroid autoimmunity (OR = 2·33 and 2·54). Logistic regression revealed that only high-titre GADA was associated with development of thyroid autoimmunity in patients with T1DM and LADA (OR = 3·50 and 3·10, respectively), and the presence of thyroid antibody predicted high risk for thyroid dysfunction in patients with T1DM and LADA (OR = 9·25 and 10·70, respectively). Regular screening of thyroid antibody and function are recommended, especially in patients with T1DM and LADA with high GADA titre.

This study aimed to determine the effect of antiretroviral therapy (ART) on glycemia and transaminase levels in HIV-infected patients in Limbe, Cameroon. A total of 200 ART-experienced patients and 30 ART-naive HIV-infected controls were recruited after submitting signed informed consent forms. The blood samples collected were screened for hepatitis B and C, and liver transaminases and random blood sugar (RBS) levels were determined spectrophotometrically. No significant correlation existed between the RBS and transaminase levels with either the duration of ART or the duration since HIV diagnosis. Although both groups of patients appeared to have similar transaminase and RBS levels, after controlling for confounders, patients on ART had significantly higher aspartate aminotransferase levels, significantly lower alanine aminotransferase levels, and slightly (but not significantly) lower glycemia levels (respective mean differences of 14.92 IU/L, P = .00; 11.95 IU/L, P = .00; and 7.60 mg/dL, P = .19). These changes need to be considered in monitoring patients on ART in this setting and other similar settings.

Background and Aims: The prevalence of latent autoimmune diabetes in adults (LADA) among diabetic patients is less recognized and underdiagnosed. The aim of this study was to determine the prevalence of LADA in type 2 diabetic patients and to compare the characteristics of these two groups in Torbat-e Heydarieh, Iran. Materials and Methods: Totally, 198 male and 277 female patients diagnosed with type 2 diabetes are aged between 35 -70 years were selected and the glutamic acid decarboxylase antibodies (GADA) assessment was used for the diagnosis of LADA in them. GADA in their sera was measured by commercial anti-GAD enzyme-linked immunosorbent assay (ELISA) kit. In addition, blood pressure, sera C-peptide and cholesterol levels was measured and compared in the mentioned two groups. Demographic data including age, gender, age at diagnosis, family history of diabetes, Body mass index (BMI) and need for insulin therapy were collected from subjects and data were analyzed using SPSS software. Results: Of 475 patients, 53 ones (11.2%) were GADA positive. Significant difference was found between GADA positive and GADA negative patients in terms of mean age, C-peptide levels, cholesterol levels and need for insulin therapy to control the disease. As for gender, family history of diabetes, BMI value and hypertension there was no significant correlation between these two groups. Conclusion: The prevalence of LADA in diabetic patients was 11.2%. Presence of GAD antibodies in diabetic patients is related to reduced levels of C-peptide, increased cholesterol levels and the need for insulin during the follow-up.

Background: C-peptide is a reliable method for estimating the beta-cell residual function. The objective of this study to assess the variables associated with persistence of C-peptide secretion among patients with Type 1 diabetes mellitus (T1DM). Patients and Methods: This was a cross-sectional study conducted from October 2015 to September 2016. This study enrolled patients with T1DM with at least 1 year or more duration. Random C-peptide with concomitant plasma glucose at least 144 mg/dl (8 mmol/l) was measured and at this cutoff considered as a stimulated value. Variables that were assessed were age at the time of enrollment, age at the diagnosis of diabetes, gender, family history of diabetes, duration of diabetes, frequency of insulin per day, insulin dose (units/kg/day), type of insulin, devices delivery, body mass index (BMI) at enrollment, blood pressure, glucose (plasma), lipid profile, glycated hemoglobin (HbA1c), thyrotropin (TSH), and antibodies to glutamic acid decarboxylase (GAD65), thyroid peroxidase antibodies (anti-TPO), and tissue transglutaminase antibodies-IgA (anti-TTG-IgA). Results: A total 324 patients were included in the study. A higher level of C-peptide has been seen if the disease acquired at the age of 18 years and older with detectable C-peptide observed among 17.7% of those diagnosed at age <18 years versus 31.7% for those aged 18 years or above. The more the duration of diabetes, the more is the loss of C-peptide. On logistic regression analysis, only duration of diabetes <6 years, and insulin dose <1 U/kg/day were statistically significantly associated with the detectable level of C-peptide in this cohort of T1DM. Conclusion: Diagnosis of TIDM at a late age, positive family history of diabetes, those requiring <1 U of insulin per kg per day, and higher fasting glucose was associated with higher and more detectable C-peptide. On multivariable analysis, the only duration of diabetes <6 years and insulin dose <1 U of insulin per kg per day remains significantly associated with detectable C-peptide after at least 1 year from the diagnosis of T1DM. The gender, the BMI, blood pressure, the number of insulin injections per day, GAD65, anti-TTG-IgA, anti-TPO antibodies together with random glucose, lipid profile, HbA1c, or TSH levels failed to predict detectable C-peptide at 1 year from the diagnosis of T1DM.

Objective To investigate the predictive factors of residual β-cell function in young patients with newly-diagnosed type 1 diabetes mellitus. Methods After an average follow-up of (35.1±13.8)months, a total of 110 young patients with type 1 diabetes mellitus were analyzed. At baseline and follow-up, oral glucose tolerance test(OGTT)and C-peptide release test were carried out, the levels of HbA1C, glutamic acid decarboxylase-antibody(GAD), and the genetic polymorphisms of human leukocyte antigen(HLA)-Ⅱ were detected. The patients were divided into two groups: high-residual β-cell function group(high-RBF group)and low-residual β-cell function group(low-RBF group), which were defined as stimulated C-peptide(Cmax)≥0.6 ng/ml and <0.6 ng/ml at endpoint, respectively. Logistic regression analyses were performed to explore the factors that influence long-term residual β-cell function. Results Compared with low-RBF group, Cmax levels were higher [(1.87±1.35 vs 0.23±0.19)ng/ml, P<0.01], HbA1C levels were lower [(7.00±1.69 vs 8.39±1.77)%, P < 0.01], insulin dosages were lower[(0.62±0.17 vs 0.79±0.17)IU·kg-1·d-1,P <0.01] in high-RBF group at endpoint. Logistic regression analysis suggested that factors including age of onset(years)[OR=0.82, 95%CI 0.73-0.92, P=0.001], higher HLA risk status(OR=4.73, 95%CI 1.28-17.52, P=0.020), female sex(OR=3.39, 95%CI 1.03-11.22, P=0.045), diabetic ketoacidosis history at onset(OR=8.71, 95%CI 2.31-32.83, P=0.001), and higher mean HbA1C levels(OR=2.46, 95%CI 1.47-4.11, P=0.001)were related to low residual β-cell function. Compared with mean HbA1C level during diabetes course, predicted probability value for the four baseline factors(diagnosis age, HLA risk status, gender, and diabetic ketoacidosis history)as the onset state of type 1 diabetes patients was higher[(OR=145.75, 95%CI 17.30-1 228.31, P<0.01)vs(OR=1.82, 95%CI 1.24-2.69, P=0.003)]. Conclusion Younger age of onset, female, higher HLA risk status, diabetic ketoacidosis history at onset and poor glycemic control during diabetes course were the predictive factors of low residual β-cell function in the development of the disease. Compared with mean HbA1C level during diabetes course, an onset state of type 1 diabetes mellitus patients is more valuable to predict long-term residual β-cell function. (Chin J Endocrinol Metab, 2016, 32: 728-733) Key words: Diabetes mellitus, type 1; Islet β-cell function; Human leukocyte antigen class Ⅱ; Prognosis

A person with old age will experience decreased organ function, as well as sensitivity to insulin. WHO data in 2011 found the world population who suffer from Diabetes Militus increase every year, this is because of low knowledge in managing healthy lifestyle, so it is necessary to do lifestyle management activity of elderly to lower blood sugar level. This study aims to determine the effect of mild walking 30 minutes to lower blood sugar levels diabetes mellitus type 2.The design used in this research is pre experiment One-Group Pre-post Test Design. The population in this study is elderly suffer of diabetes mellitus type 2 in Dukuh village conducted on May 19, 2017, using purposive technique with a total of 24 respondents. Data retrieval with light treatment 30 minutes. Then the data processed with Editing, Coding, Scoring and Tabulating techniques and tested with Wilcoxon Sign Rank Test statistics. Before the procedure was light 30 minutes from 24 respondents Most had random blood sugar level in the category of diabetes that is 20 respondents (83%), after a light treatment 30 minutes most of the respondents had random blood sugar level in the category of diabetes that is 14 respondents. (58.3%). The results showed that there was a 30 minute light walking exercise effect to lower blood glucose levels in elderly people with type 2 diabetes mellitus shown by p value = 0,000 and α = 0.05 which means value (p≤0,05). Therefore, researchers believe that a mild treatment of 30 minutes is very important for people with type 2 diabetes mellitus so that proven to lower blood sugar levels in people with diabetes mellitus.

IDF21-0574 Type 1 Diabetes onset and COVID-19 infection in a child with Sanjad Sakati Syndrome: a case from Kuwait

Background The study investigated the relationship between random blood sugar (RBS) levels and clinical outcomes in patients with relapsing-remitting multiple sclerosis (RRMS) following intravenous methylprednisolone (IVMP) treatment. Objective Determine the relationship between blood glucose level during intravenous methylprednisolone (IVMP) treatment and the degree of motor &amp; cognitive recovery afterwards in relapsing remitting multiple sclerosis patient. Subjects and Methods This observational analytical prospective study was conducted on 40 patients with relapsing remitting multiple sclerosis (RRMS) at Nasr city hospital of health insurance – Ain Shams University Hospital between May 2022 and November 2022. The study population was adults with confirmed diagnosis of relapsing-remitting multiple sclerosis who are currently experiencing a relapse. Patients with other neurological diseases, cognitive disorders, diabetes, certain medications, learning disabilities, or who are pregnant or using hormone replacement therapy are excluded. The study tools for this study include a clinical assessment of MS patients, the use of the Expanded Disability Status Scale (EDSS) to assess motor deficit, the use of the Symbol Digit Modalities Test (SDMT) to assess cognitive function, and the measurement of fasting blood glucose. The purpose of these study tools is to assess the effects of IVMP induced hyperglycemia on motor &amp; cognitive relapse recovery in relapsing remitting multiple sclerosis patients. Results The study sample included 40 patients with definite RRMS, and the primary outcome measure was EDSS. The study found that hyperglycemia may be a potential predictor of poor treatment response in MS patients. The study also identified cut-off values for RBS levels that can predict the probability of recovery after IVMP treatment. The significant relationship between older age of onset and poorer SDMT performance supports previous research that has found age to be a risk factor for cognitive decline in MS. Similarly, the significant relationship between longer duration of illness and poorer SDMT performance is consistent with previous studies that have found disease duration to be a predictor of cognitive impairment in MS. Conclusion The present study provides further evidence of the association between hyperglycemia and poor outcomes in patients with RRMS following IVMP treatment. The findings suggest that RBS levels may be a useful prognostic marker for predicting cognitive and functional outcomes in MS patients. Clinicians should consider monitoring and managing RBS levels in MS patients to optimize treatment outcomes. However, further studies are needed to elucidate the underlying mechanisms and to determine the optimal cut-off values for RBS levels in predicting MS outcomes.

Objective To investigate the current situation of islet autoantibodies detection in China, and to evaluate assay proficiency to improve the diagnosis and classification of autoimmune diabetes. Methods Islet autoantibodies questionnaire was sent to 20 members of National Clinical Research Center for Metabolic Diseases in April 2015. In accordance with international standardization of islet autoantibodies program, sera of 50 patients with newly diagnosed type 1 diabetes, 100 healthy controls were blindly numbered and assayed in three core units using radioligand assay. The area under the receiver operating characteristic curve (ROC) (AUC) was applied to evaluate the sensitivity and specificity, as well as the consistency of the results. Mann-Whitney U test was used to compare the WHO values of type 1 diabetes mellitus and healthy volunteers autoantibodies. Linear correlation analysis was applied to evaluate the correlation of 3-lab results after converting into WHO standard unit. Results (1) All of 20 hospitals carried out the detection of glutamic acid decarboxyase antibody (GADA), and 7 hospitals detect GADA+ protein tyrosinephosphate antibody(IA-2A) paralelly (35%); The detection methods included immunoblotting (30%), chemiluminescence (20%), enzyme-linked immunosorbent assay (20%), radioimmunoassay (15%) and radioligand assay (15%). (2) Among three core units, sensitivity for GADA detection ranged from 72% to 80%, while specificity ranged from 95% to 100%; sensitivity for IA-2A detection ranged from 38% to 58% with the specificity from 98% to 100%. The ROC analysis showed that the AUC of GADA was 0.897-0.935, of IA-2A was 0.716-0.749. The consistency of GADA detection among three units was 92.7%, of IA-2A was 92%. Conclusion Islet autoantibodies detection in Chinese hospitals need to be standardized. Radioligand assay is recommended for centralized detection of islet autoantibodies in China. Key words: Diabetes mellitus, type 1; Standardization; Glutamic acid decarboxylase antibody; Autoantibodies to tyrosine phosphatase-like protein