Clinical,autoimmune, and genetic characteristics of adult-onset diabetic patients with GAD autoantibodies in Japan (Ehime Study)

OBJECTIVE: To characterize the clinical, autoimmune, and genetic features in Japanese adult-onset diabetic patients with GAD autoantibodies. RESEARCH DESIGN AND METHODS: GAD autoantibodies (GADab) were screened in 4,980 diabetic patients with age of onset >20 years in the hospital-based Ehime Study, and the GADab-positive (GADab(+)) patients were then divided into two groups according to their insulin secretion and compared with nondiabetic subjects. The insulin-deficient state was defined as <0.33 nmol/l serum C-peptide (CPR) at 2 h postprandial or 6 min after a 1-mg glucagon load. RESULTS: GADab was detected in 188 (3.8%) of the 4,980 diabetic patients tested. Of these patients, 72 (38.3%) were classified as insulin deficient, 97 (51.6%) were classified as non-insulin deficient, and 19 (10.1%) were unclassified. The GADab(+) insulin-deficient patients were characterized by young age at onset of diabetes, low BMI, low maximum BMI, and high levels of HbA(1c). The prevalence of IA-2 autoantibodies and thyrogastric autoantibodies in the GADab(+) insulin-deficient patients were significantly higher than those in the GADab(+) non-insulin-deficient patients (P < 0.05). GADab(+) patients with insulin deficiency had increased frequencies of HLA DRB1*0405-DQB1*0401, *0802-*0302, and *0901-*0303 haplotypes, whereas the frequency of only HLA DRB1*0405-DQB1*0401 was increased in the case of GADab(+) non-insulin-deficient patients. Of note is the fact that the GADab(+) non-insulin-deficient group did not differ from healthy control subjects with respect to type 1 diabetes protective haplotype HLA DRB1*1502-DQB1*0601. A total of 13% of the GADab(+) patients with diabetes had genotypes comprising the DRB1*1501-DQB1*0602 or *1502-*0601 and were characterized by old age at onset of diabetes, high BMI, resistance to the insulin-deficient state, low titer of GADab, and low frequency of other organ-specific autoantibodies. CONCLUSIONS: We conclude that GADab(+) non-insulin-deficient patients differ from GADab(+) patients with insulin deficiency with respect to clinical characteristics, humoral autoimmunity to other organ-specific autoantibodies, as well as HLA class II genes.     

乙型糖尿病患者甲状腺激素及自身抗体异常的临床分析

目的：通过分析乙型糖尿病患者和健康对照组甲状腺激素及自身抗体的异常情况,探讨乙型糖尿病和甲状腺疾病的关系。方法对396例乙型糖尿病患者及411例健康体检者（对照组）测定其血清促甲状腺激素（TSH）、游离三碘甲状腺原氨酸（FT3）、游离甲状腺素（FT4）水平,同时测定其抗甲状腺球蛋白抗体（TGAb）及抗甲状腺过氧化物酶抗体（TPOAb）。结果在健康对照组中,甲状腺激素异常发病率为7．5％,其中男性为5．5％,女性为9．4％,女性亚甲减患病率为4．7％,高于男性亚甲减患病率的1．5％,差异有统计学意义（P ＜0．05）;健康对照组中 TPOAb 阳性率为10．2％,TGAb 阳性率为6．6％。在乙型糖尿病（T2DM）患者中,甲状腺激素异常发病率为16．2％,男性为12．3％,女性为20．5％,其中女性亚甲减患病率为9．2％高于男性4．3％,差异有统计学意义（P ＜0．01）,T2DM 患者亚甲减占甲状腺功能异常发生率的40．6％;TPOAb 阳性率为15．2％,TGAb阳性率为7．1％。结论乙型糖尿病患者中甲状腺疾病患病率较健康对照组明显增加,以女性亚甲减为主;对糖尿病患者进行甲状腺自身抗体筛查及定期监测 FT3、FT4、TSH,对糖尿病患者的病情的评估、预后的判断和指导治疗具有重要的临床意义。     

Clinical heterogeneity in patients with FOXP3 mutations presenting with permanent neonatal diabetes

OBJECTIVE—Immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) syndrome is caused by FOXP3 mutations. We aimed to determine the prevalence, genetics, and clinical phenotype of FOXP3 mutations in a large cohort with permanent neonatal diabetes (PNDM).RESEARCH DESIGN AND METHODS—The 11 coding exons and the polyadenylation region of FOXP3 were sequenced in 26 male subjects with diabetes diagnosed before 6 months of age in whom common genetic causes of PNDM had been excluded. Ten subjects had at least one additional immune-related disorder, and the remaining 16 had isolated diabetes.RESULTS—We identified four hemizygous FOXP3 mutations in 6 of 10 patients with associated immune-related disorders and in 0 of 16 patients with isolated diabetes (P = 0.002). Three patients with two novel mutations (R337Q and P339A) and the previously reported L76QfsX53 developed classic IPEX syndrome and died within the first 13 months. The novel mutation V408M was found in three patients from two unrelated families and had a mild phenotype with hypothyroidism and autoimmune enteropathy (n = 2) or nephrotic syndrome (n = 1) and survival to 12–15 years.CONCLUSIONS—FOXP3 mutations result in ∼4% of cases of male patients with permanent diabetes diagnosed before 6 months. Patients not only have classic IPEX syndrome but, unexpectedly, may have a more benign phenotype. FOXP3 sequencing should be performed in any male patient with the diagnosis of diabetes in the first 6 months who develops other possible autoimmune-associated conditions, even in the absence of full IPEX syndrome.Type 1 diabetes is the leading cause of diabetes among children except for those in whom diabetes is diagnosed before the age of 6 months. HLA studies have shown that patients in whom diabetes is diagnosed within the first 6 months of life (permanent neonatal diabetes [PNDM]) do not harbor high-risk HLA haplotypes and hence are very unlikely to have classic type 1 diabetes (1,2). These patients should be tested for monogenic causes of neonatal diabetes.Mutations in FOXP3 have been associated with a severe, early-onset, male-limited autoimmunity syndrome known as IPEX (immune dysregulation, polyendocrinopathy, enteropathy, X-linked; OMIM [Online Mendelian Inheritance in Man] 304930) (3–5). The gene maps to chromosome Xp11.23 and encodes a 431–amino acid protein, also named scurfin, required for the generation and functioning of CD4⁺CD25⁺ regulatory T lymphocytes. FOXP3-expressing CD4⁺ T cells are potent suppressors of self-reactive T-cell activation and proliferation, presumably via direct cell-cell interaction. Thus, lack of these cells results in an uncontrolled autoimmune reactivity in male patients with hemizygous FOXP3 mutations (6). In keeping with an X-linked recessive mode of inheritance, heterozygous carrier females remain completely asymptomatic, but each son has a 50% risk of being affected with IPEX syndrome. One patient with IPEX syndrome due to recessive inheritance of CD25 mutations has recently been reported (7).Most patients with IPEX syndrome described to date have developed symptoms shortly after birth or during the first 3–4 months of life. The most common findings have been enteropathy (nearly 100% of patients), diabetes (∼70%), skin disease (∼65%), failure to thrive (∼50%), thyroiditis (∼30%), and recurrent infections (∼20%). Less common additional features include autoimmune cytopenias, pneumonitis, nephritis, hepatitis, vasculitis, arthritis, myositis, and alopecia as well as lymphadenopathy and splenomegaly. These disorders often appear sequentially rather than simultaneously, and the affected organ spectrum varies substantially from patient to patient (8). The life expectancy of patients with IPEX syndrome rarely extends beyond infancy.However, a milder phenotype has been reported in a number of patients, who can live longer, sometimes into adulthood. Enteropathy was present in virtually all of them, although diabetes was frequently absent (9–11).To our knowledge, FOXP3 has not been systematically studied before in patients with early-onset diabetes. Hence, we aimed to explore the prevalence of FOXP3 mutations in the largest worldwide cohort of PNDM.     

Clinical and metabolic features of adult-onset diabetes caused by ABCC8 mutations

OBJECTIVE

Gain-of-function ABCC8/sulfonylurea (SU) receptor 1 mutations cause neonatal diabetes mellitus (NDM) or late-onset diabetes in adult relatives. Given the effectiveness of SU treatment in ABCC8-NDM patients, we further characterized late-onset ABCC8-associated diabetes.

RESEARCH DESIGN AND METHODS

Seven adult subjects from three NDM families and one family with type 2 diabetes were studied. Insulin secretion and insulin sensitivity were assessed using clamp techniques. We screened 139 type 2 diabetic patients who were well controlled by SU for ABCC8 mutations.

RESULTS

ABCC8 mutation carriers exhibited glucose intolerance, frank diabetes, or insulin-requiring diabetes since diagnosis. HbA_1c improved in five SU-treated patients. Insulin secretion capacity was impaired in three patients compared with adult control subjects but was restored after a 4-week SU trial in two patients. Cohort screening revealed four SU-treated patients with ABCC8 mutations, two of which are likely causal.

CONCLUSIONS

Although of rare occurrence, recognition of adult-onset ABCC8-associated diabetes may help in targeting patients for SU therapy.Activating ABCC8 mutations are responsible of neonatal diabetes mellitus (NDM) (1–5) and late-onset diabetes with variable clinical phenotypes (2,4,6,7). Sulfonylurea (SU) drugs bind the high-affinity pancreatic β-cell–expressed sulfonylurea receptor (SUR 1) (encoded by ABCC8) of the ATP-sensitive K⁺ channels (K_ATP channels) and close them, subsequently stimulating insulin secretion (8). SU treatment may successfully replace insulin to control diabetes during the neonatal period (2,9,10).Here, we report detailed clinical and metabolic investigations in seven adult carriers of gain-of-function ABCC8 mutations (2,7,11), of whom five developed late-onset diabetes diagnosed between the ages of 14 and 39 years. We also screened an adult outpatient cohort with type 2 diabetes well controlled by SU for ABCC8 mutations.     

Time-resolved immunofluorometric dual-label assay for simultaneous detection of autoantibodies to GAD65 and IA-2 in children with type 1 diabetes

BACKGROUND: Autoantibodies to glutamic acid decarboxylase (GADAs), specifically the 65-kDa isoform GAD65, and autoantibodies to the protein tyrosine phosphatase-like molecule IA-2 (IA-2As) predict development of diabetes. Our aim was to develop a time-resolved immunofluorometric (TR-IFMA) dual-label assay method for the simultaneous detection of these autoantibodies and to evaluate the diagnostic sensitivity of the method compared with single-label TR-IFMA and fluid-phase radiobinding assay (RBA) in screening children with type 1 diabetes. METHODS: We incubated combined biotinylated GAD65 and IA-2 proteins, glutathione S-transferase (GST)-IA-2, europium-labeled GAD65, terbium-labeled anti-GST antibody, and serum sample or calibrator and transferred aliquots to a streptavidin-coated 96-well microtiter plate for a second incubation. After washing, we added Delfia Enhancement solution to each well and measured the fluorescence of Eu. We developed the Tb fluorescence signal by use of the Delfia Enhancer solution and measured it. We analyzed serum samples from a cohort of 100 children with newly diagnosed type 1 diabetes. RESULTS: The correlation coefficients between the autoantibody concentrations measured by dual- and single-label TR-IFMA assays were 0.962 for GADA and 0.874 for IA-2A. Among 100 children with newly diagnosed diabetes, 65 of them were GADA positive in the dual-label assay, 64 in the single-label assay, and 66 in the RBA GADA assay. Seventy-four of the children tested positive for IA-2A in both TR-IFMA assay types, and 79 in the RBA IA-2A assay. CONCLUSIONS: The novel dual-label immunofluorometric assay performed comparably to the separate, single-label GADA and IA-2A assays in screening for beta-cell autoimmunity in children with newly diagnosed type 1 diabetes.     

天疱疮相关自身抗体的检测及其临床意义

目的评价抗细胞间抗体、抗桥粒芯糖蛋白1(Dsg1)抗体和抗桥粒芯糖蛋白3(Dsg3)抗体联合检测对于天疱疮诊断的临床意义,以及各项检测指标之间的相关性。方法用酶联免疫吸附试验(ELISA)检测30例天疱疮患者、14例类天疱疮患者血清中的抗Dsg1抗体和抗Dsg3抗体,采用间接免疫荧光法检测抗细胞间抗体。结果抗细胞间抗体、抗Dsg1抗体和抗Dsg3抗体在天疱疮患者中的阳性率分别为53.33%(16/30)、46.67%(14/30)、53.33%(16/30)。3项检测指标在天疱疮患者和类天疱疮患者中的阳性率差异有统计学意义。抗细胞间抗体与抗Dsg1抗体在天疱疮患者中的阳性率差异无统计学意义,2种检测结果显著相关。抗细胞间抗体与抗Dsg3抗体在天疱疮患者中的阳性率差异无统计学意义,2种检测结果显著相关。他们之间有交叉重叠现象。结论3种检测指标的联合应用可以提高临床上诊断天疱疮的敏感性。     

天疱疮相关自身抗体的检测及其临床意义

目的评价抗细胞间抗体、抗桥粒芯糖蛋白1（Dsg1）抗体和抗桥粒芯糖蛋白3（Dsg3）抗体联合检测对于天疱疮诊断的临床意义,以及各项检测指标之间的相关性。方法用酶联免疫吸附试验（ELISA）检测30例天疱疮患者、14例类天疱疮患者血清中的抗Dsg1抗体和抗Dsg3抗体,采用间接免疫荧光法检测抗细胞间抗体。结果抗细胞间抗体、抗Dsg1抗体和抗Dsg3抗体在天疱疮患者中的阳性率分别为53.33%（16/30）、46.67%（14/30）、53.33%（16/30）。3项检测指标在天疱疮患者和类天疱疮患者中的阳性率差异有统计学意义。抗细胞间抗体与抗Dsg1抗体在天疱疮患者中的阳性率差异无统计学意义,2种检测结果显著相关。抗细胞间抗体与抗Dsg3抗体在天疱疮患者中的阳性率差异无统计学意义,2种检测结果显著相关。他们之间有交叉重叠现象。结论3种检测指标的联合应用可以提高临床上诊断天疱疮的敏感性。     

青壮年糖尿病患者自身抗体联合检测的临床应用价值

目的探讨谷氨酸脱羧酶抗体(GAD-Ab)、胰岛细胞抗体(ICA)、胰岛自身抗体(IAA)和蛋白酪氨酸磷酸酶抗体(IA-2-Ab)联合检测对青壮年糖尿病患者的应用价值。方法采用免疫印迹法检测212例青壮年糖尿病患者和40例健康人血清中GAD-Ab、ICA、IAA和IA-2-Ab,并对4项自身抗体全阴患者与有1项以上阳性患者的空腹血糖、餐后2h血糖、糖化血红蛋白等血液生化指标进行比较。结果 212例青壮年糖尿病患者GAD-Ab、ICA、IAA和IA-2-Ab的阳性率分别为29.2%、21.7%、13.2%和11.3%,4项自身抗体全阴患者126例,占59.4%,与有1项以上阳性患者比较,其空腹血糖、餐后2h血糖和糖化血红蛋白水平差异无统计学意义(P>0.05)。结论4项联合检测对青壮年糖尿病患者的诊断及治疗方案的制定有重要意义。     

糖尿病患者胰岛自身抗体测定与血清C肽水平的关系

目的研究胰岛自身抗体与胰岛β细胞功能的关系.方法测定302例住院的糖尿病(DM)患者的血清C肽、胰岛细胞抗体(ICA)、谷氨酸脱羧酶抗体GADA)的水平.并按病程的长短、抗体的阳性进行分组分析.结果46例速发型1型DM中,21.7%呈现ICA阳性,39.1%呈现GADA阳性.在临床初诊为2型DM的256例患者中,18.7%有一种以上抗体阳性,其中4.7%呈现ICA阳性,15.6%呈现GADA阳性.并且随着病程的延长,患者均有空腹和餐后2hC肽水平的下降,下降速度以1型DM最快,LADA次之,2型DM最慢.结论GADA和ICA联合测定有助于诊断LADA,而且LADA患者β细胞功能衰退较慢,保护残存β细胞有利于延缓病情发展.     

GAD65-reactive T cells are activated in patients with autoimmune type 1a diabetes

Insulin-dependent type 1 diabetes is an autoimmune disease mediated by T lymphocytes recognizing pancreatic islet cell antigens. Glutamic acid decarboxylase 65 (GAD65) appears to be an important autoantigen in the disease. However, T cells from both patients with type 1 diabetes and healthy subjects vigorously proliferate in response to GAD65 stimulation ex vivo, leading us to postulate that the critical event in the onset of human diabetes is the activation of autoreactive T cells. Thus, we investigated whether GAD65-reactive T cells in patients with diabetes functioned as previously activated memory T cells, no longer requiring a second, costimulatory signal for clonal expansion. We found that in patients with new-onset type 1 diabetes, GAD65-reactive T cells were strikingly less dependent on CD28 and B7-1 costimulation to enter into cell cycle and proliferate than were equivalent cells derived from healthy controls. We hypothesize that these autoreactive T cells have been activated in vivo and have differentiated into memory cells, suggesting a pathogenic role in type 1 diabetes. In addition, we observed different effects with selective blockade of either B7-1 or B7-2 molecules; B7-1 appears to deliver a negative signal by engaging CTLA-4, while B7-2 engagement of CD28 upregulates T cell proliferation and cytokine secretion.     

多种自身抗体检测在狼疮肾炎中的临床意义

目的通过检测系统性红斑狼疮（SLE）、狼疮肾炎（LN）患者血清抗nRNP、抗Sm、抗dsDNA、ANCA及ANuA等自身抗体，探讨几种自身抗体在狼疮肾炎患者中的临床意义。方法狼疮肾炎患者55例，非狼疮肾炎的SLE患者60例为对照组，血清抗dsDNA、ANCA采用间接免疫荧光法测定，ANCA间接免疫荧光法阳性者用免疫印迹法进一步确认，抗nRNP、抗Sm及ANuA采用欧蒙斑点法测定。结果两组病程差异有统计学意义（P〈0．001），LN发病率为SLE患者的47．8％，抗nRNP及抗Sm阳性率LN组较对照组高，但无统计学意义（P=0．395、P=0．483）；LN组抗dsDNA、ANCA及ANuA阳性率较对照组高且差异有统计学意义（P=0．028、P=0．024，P〈0．001）。结论SLE病程是合并LN的重要因素之一，血清抗dsDNA、ANCA及ANuA等自身抗体检测均有助于LN的诊断。     

Clinical study of autoantibodies in type 1 diabetes mellitus children with ketoacidosis or microalbuminuria

AimsThe study aimed to investigate the value of autoantibodies in predicting the risk of ketoacidosis or microalbuminuria in children with type 1 diabetes mellitus.MethodsClinical data and laboratory indicators of 80 patients with type 1 diabetes admitted to the Department of Endocrinology in Tianjin Children''s Hospital, from June 2017 to March 2019, were retrospectively analyzed. The patients were divided into two groups: diabetes without ketoacidosis group (n = 20) and diabetes with ketoacidosis group (n = 60). The differences in general data, laboratory test indexes, and autoantibodies between the two groups were analyzed. Finally, ROC curves and multivariate logistic regression analysis were used to explore the value of autoantibodies in patients with ketoacidosis or microalbuminuria.ResultsA total of 80 children with type 1 diabetes were assessed, including 35 boys and 45 girls, ranging in age from 10 months to 15 years. The concentration of GADA, IA2A, and ZnT8A was not statistically different between the two groups, but the positive rate of ZnT8A was statistically significant (p = 0.038) and had a diagnostic value for the occurrence of ketoacidosis (p = 0.025). ZnT8A‐positive patients had a higher titer of IA2A and a more frequent prevalence of GADA and IA2A than ZnT8A‐negative patients (p < 0.01). In multivariate logistic regression analyses, the presence of positive ZnT8A was associated with a higher risk of microalbuminuria independent of age, sex, and BMI (OR = 4.184 [95% CI 1.034~16.934], p = 0.045).ConclusionsThe positive ZnT8A had diagnostic value for ketoacidosis in children with type 1 diabetes and had the highest specificity among the three kinds of autoantibodies. Moreover, ZnT8A positivity was related to a higher titer of IA2A and more frequent occurrence of multiple diabetes‐related autoantibodies. Besides, the presence of positive ZnT8A was an independent risk factor of microalbuminuria in children with type 1 diabetes. Therefore, we can infer that positive ZnT8A may be related to ketoacidosis and microalbuminuria, accelerating the progression of T1DM.     

慢性乙型肝炎儿童中的自身抗体检测分析及临床意义初探

目的检测慢性乙型肝炎儿童自身抗体的阳性率,探讨其自身抗体存在的临床意义。方法采用间接免疫荧光法检测84例慢性乙型肝炎儿童、69例慢性乙型肝炎成人和15例正常儿童抗核抗体(ANA)的阳性率、滴度、核型和抗平滑肌抗体(SMA)、抗线粒体抗体(AMA)、抗肝肾微粒体抗体(LKM)、抗胃壁细胞抗体(APCA)的阳性率。同时检测患者的ALT、AST,对慢性乙型肝炎儿童取肝活检组织作病理组织学检查。结果 (1)慢性乙型肝炎儿童组总自身抗体阳性率为19.0%,较成人慢性乙型肝炎患者组为低(P<0.05)。(2)慢性乙型肝炎儿童组检出的ANA以低滴度(1:100)为主,有3例滴度为1:320;ANA核型全部为均质型;仅有1例SMA阳性,未见其他自身抗体阳性。(3)慢性乙型肝炎儿童自身抗体阳性组的ALT、AST水平均高于自身抗体阴性组(P<0.05)。(4)慢性乙型肝炎儿童自身抗体阳性组肝脏病理G>2者占43.8%,较自身抗体阴性组G>2者(16.2%)比例明显增高,差异有统计学意义(P<0.05)。结论慢性乙型肝炎儿童中也有一定比例存在自身抗体,但较成人慢性乙型肝炎患者为低。自身抗体的产生与肝损伤程度有一定相关性,检测慢性乙...     

GAD65 autoantibody responses in Japanese latent autoimmune diabetes in adult patients

OBJECTIVE—To determine whether development of insulin requirement in patients with latent autoimmune diabetes in adults (LADA) is accompanied with the emergence of a type 1 diabetes–like autoimmune response.RESEARCH DESIGN AND METHODS—We correlated β-cell–specific autoimmunity reflected in autoantibodies to the 65-kDa isoform of GAD (GAD65) with insulin requirement. We determined GAD65Ab epitope specificities in type 1 diabetic patients, LADA patients without insulin requirement (nonprogressed), and LADA patients that had developed insulin requirement (progressed).RESULTS—Recognition of a type 1 diabetes–specific GAD65Ab epitope was more pronounced in type 1 diabetic patients than in nonprogressed (P < 0.001) or progressed (P < 0.01) LADA patients, with no significant differences between the two LADA cohorts. These differences were particularly pronounced in samples with GAD65Ab titers <1,000 units/ml, with no differences in epitope specificities in samples with higher GAD65Ab titers. Disease duration (initial diabetes diagnosis until sample collection or development of insulin requirement) in nonprogressed and progressed LADA patients, respectively, was not correlated with epitope specificity, suggesting lack of epitope maturation. This was supported by epitope analyses of longitudinal samples from LADA patients during progression to insulin requirement.CONCLUSIONS—First, the GAD65Ab-specific autoimmune reaction in type 1 diabetic patients with low and moderate GAD65Ab titers differs from that in LADA patients, irrespective of insulin requirement. Second, the GAD65Ab-specific autoimmune response in LADA patients does not change after their initial diabetes diagnosis. Finally, LADA patients with high GAD65Ab titers resemble type 1 diabetic patients in their GAD65Ab epitope specificity.Latent autoimmune diabetes in adults (LADA) consists of a subgroup (∼10%) of adult patients initially diagnosed with type 2 diabetes, who show signs of β-cell autoimmunity and eventually develop insulin requirement (1,2). Signs of β-cell autoimmunity, such as the well-characterized insulin autoantibodies, glutamate decarboxylase (GAD65), and the tyrosine phosphatase–like protein insulinoma-associated protein-2, indicate significant damage of the β-cells and subsequent development of insulin requirement in these patients (1). While autoantibodies to insulin and insulinoma-associated protein-2 antibody (Ab) are inversely correlated with age at onset, GAD65Ab shows no, and in some studies even a positive, correlation with age at onset and is therefore a particularly attractive marker for autoimmune diabetes in the adult population (3,4). Moreover, GAD65Ab can be detected years after the clinical onset of the disease, indicating that these autoantibodies may be permanent markers for the autoimmune response (5,6).Notably, not all LADA patients progress to insulin requirement, raising the possibility that the autoimmune response in these patients resembles that in autoantibody-positive healthy individuals, with no significant risk for development of insulin requirement (7,8). A better understanding of the autoimmune response is necessary to predict insulin requirement in LADA patients, which is important to prevent escalation of blood glucose levels and subsequent complications.In previous studies, we have investigated the humoral immune response toward GAD65 as a reflection of islet cell destruction (9). It remains unclear whether the autoimmune response in LADA patients and type 1 diabetic patients differs or whether only the duration of the prodomal period distinguishes between the two groups (10). Therefore, we compared the GAD65-specific humoral autoimmune response in type 1 diabetic patients with that in LADA patients who had or had not progressed to insulin requirement.