Testing for type 1 diabetes autoantibodies in gestational diabetes mellitus (GDM): is it clinically useful?

Estimation of Individual Positive Anti-Islet Autoantibodies from 3 Screen ICA Titer

The 3 Screen ICA ELISA is a novel assay capable of simultaneously measuring autoantibodies to glutamic acid decarboxylase (GADA), insulinoma-associated antigen-2 (IA-2A), and zinc transporter 8 (ZnT8A), making it a valuable tool for screening type 1 diabetes. Despite its advantages, it cannot specify which individual autoantibodies are positive or negative. This study aimed to estimate individual positive autoantibodies based on the 3 Screen ICA titer. Six hundred seventeen patients with type 1 diabetes, simultaneously measured for 3 Screen ICA and three individual autoantibodies, were divided into five groups based on their 3 Screen ICA titer. The sensitivities and contribution rates of the individual autoantibodies were then examined. The study had a cross-sectional design. Sixty-nine percent (424 of 617) of patients with type 1 diabetes had 3 Screen ICA titers exceeding the 99th percentile cut-off level (20 index). The prevalence of GADA ranged from 80% to 100% in patients with a 3 Screen ICA over 30 index and 97% of patients with a 3 Screen ICA ≥300 index. Furthermore, the prevalence of all individual autoantibodies being positive was 0% for ≤80 index and as high as 92% for ≥300 index. Significant associations were observed in specific titer groups: the 20-29.9 index group when all the individual autoantibodies were negative, the 30-79.9 index group when positive for GADA alone or IA-2A alone, the 30-299.9 index group when positive for ZnT8A alone, the 80-299.9 index group when positive for both IA-2A and ZnT8A, the 300-499.9 index group when positive for both GADA and ZnT8A, and the ≥300 index group when positive for all individual autoantibodies. These results suggest that the 3 Screen ICA titer may be helpful in estimating individual positive autoantibodies.

The Prognosis of Glutamic Acid Decarboxylase Antibodies in Women With Hyperglycemia in Pregnancy

CONTEXT

We recently reported that the presence of glutamic acid decarboxylase antibodies (GADA) was not associated with large-for-gestational-age infants in women with hyperglycemia in pregnancy (HIP).

OBJECTIVE

We explored the association between the presence of GADA and other HIP-related adverse pregnancy outcomes.

METHODS

This observational prospective study, conducted at a university hospital in a suburb of Paris, France, included 1182 consecutive women with HIP measured for GADA at HIP care initiation between 2012 and 2017. Post hoc analyses for outcomes included gestational weight gain, insulin therapy, cesarean delivery, hypertensive disorders, small-for-gestational-age infant, prematurity, and neonatal hypoglycemia.

RESULTS

Of the 1182 women studied, 87 (7.4%) had positive (≥ 1 IU/mL) GADA. Although socioeconomic, clinical, and biological characteristics were similar across women in the positive and negative GADA groups, higher fasting plasma glucose values during early HIP screening were observed in the former (5.5 ± 1.5 vs 5.2 ± 0.7 mmol/L respectively, P < .001). At HIP care initiation, fructosamine levels were higher in women with positive GADA (208 ± 23 vs 200 ± 18 µmol/L; P < .05). In the homeostatic model assessment, insulin resistance (HOMA-IR) and beta secretion (HOMA-B) rates were similar in both groups. Gestational weight gain and the rates of all adverse outcomes were similar in both groups except for cesarean delivery (18.4 and 27.3% for positive and negative GADA, respectively; adjusted odds ratio 0.49 [95% CI, 0.26-0.92], P = .026).

CONCLUSION

Universal measurement of GADA in women with HIP highlighted that 7.4% had positive GADA. No association was observed between GADA and HIP-related adverse pregnancy outcomes, except a lower risk of cesarean delivery.

Autoantibodies predict type 1 diabetes after gestational diabetes - a 23-year cohort study

Objective

To study the predictive value of autoantibodies for type 1 (T1DM) and type 2 (T2DM) diabetes morbidity after gestational diabetes (GDM) in a 23-year follow-up study.

Design

Prospective population-based cohort study.

Methods

We studied 391 women with GDM, and 391 age- and parity-matched controls, who delivered in 1984-1994. Four autoantibodies were analysed in first-trimester blood samples: islet cell autoantibodies (ICAs), glutamic acid decarboxylase autoantibodies (GADAs), insulin autoantibodies (IAAs) and insulinoma-associated antigen-2 autoantibodies (IA-2As). Two follow-up questionnaires (1995-1996, 2012-2013) were sent to assess development of T1DM and T2DM. Predictive value of autoantibodies and clinical factors were analysed by conditional linear regression and ROC analyses.

Results

Single autoantibody positivity was detected in 12% (41/342) of the GDM cohort and in 2.3% (8/353) of the control cohort. In the GDM cohort, 2.6% (9/342) tested positive for two autoantibodies and 2.3% (8/342) for three autoantibodies, whereas only one subject in the control cohort had two autoantibodies. ICA positivity was found in 12.5% of the cases, followed by GADA (6.0%), IA-2A (4.9%) and IAA (1.2%). In the control cohort, GADA positivity was found in 1.4%, IA-2A in 0.8%, IAA in 0.6%, and ICA in 0.3% of the subjects. Detection of ICA, GADA and/or IA-2A autoantibodies decreased T1DM-free survival time and time to diagnosis. All subjects with three positive autoantibodies developed T1DM within seven years from the GDM pregnancy. Development of T2DM after GDM occurred independent of autoantibody positivity.

Conclusion

Development of T1DM can be reliably predicted with GADA and ICA autoantibodies during early pregnancy.

Identification of potential gene markers in gestational diabetes mellitus

This study aims to investigate underlying mechanisms of gestational diabetes mellitus (GDM). In this work, the GSE70493 dataset from GDM and control samples was acquired from Gene Expression Omnibus (GEO) database. Afterward, differentially expressed genes (DEGs) were screened between GDM and control samples. Subsequently, functional enrichment analysis and protein–protein interaction (PPI) network analysis of these DEGs were carried out. Furthermore, significant sub‐modules were identified, and the functional analysis was also performed. Finally, we undertook a quantitative real‐time polymerase chain reaction (qRT‐PCR) with the purpose of confirming several key genes in GDM development. There were totally 528 up‐regulated and 684 down‐regulated DEGs between GDM and healthy samples. The functional analyses suggested that the above genes were dramatically enriched in type 1 diabetes mellitus (T1DM) process and immune‐related pathways. Moreover, PPI analysis revealed that several members of human leukocyte antigen (HLA) superfamily, including down‐regulated HLA‐DQA1, HLA‐DRB1, HLA‐DPA1, and HLA‐DQB1 served as hub genes. In addition, six significant sub‐clusters were extracted and functional analysis suggested that these four genes in sub‐module 1 were also associated with immune and T1DM‐related pathways. Finally, they were also confirmed by qRT‐PCR array. Besides, the four members of HLA superfamily might be implicated with molecular mechanisms of GDM, contributing to a deeper understanding of GDM development.

Type 1 diabetes-related autoimmune antibodies in women with gestational diabetes mellitus and the long-term risk for glucose intolerance

AIMS

To characterize women with gestational diabetes mellitus (GDM) positive for type 1 diabetes-related autoimmune antibodies (T1D-related autoantibodies) in pregnancy and to evaluate their risk for long-term glucose intolerance.

METHODS

In a multi-centric prospective cohort study with 1843 women receiving universal screening for GDM with a 75 g oral glucose tolerance test (OGTT), autoantibodies were measured in women with GDM: insulin autoantibodies (IAA), islet cell antibodies (ICA), insulinoma-associated protein-2 antibodies (IA-2A) and glutamic acid decarboxylase antibodies (GADA). Long-term follow-up ( ± 4.6 years after delivery) with a 75 g OGTT and re-measurement of autoantibodies was done in women with a history of GDM and autoantibody positivity in pregnancy.

RESULTS

Of all women with GDM (231), 80.5% (186) received autoantibody measurement at a mean of 26.2 weeks in pregnancy, of which 8.1% (15) had one positive antibody (seven with IAA, two with ICA, four with IA-2A and two with GADA). Characteristics in pregnancy were similar but compared to women without autoantibodies, women with autoantibodies had more often gestational hypertension [33.3% (5) vs. 1.7% (3), p<0.001] and more often neonatal hypoglycemia [40.0% (6) vs. 12.5% (19), p=0.012]. Among 14 of the 15 autoantibody positive women with an early postpartum OGTT, two had impaired fasting glucose (IFG). Of the 12 women with long-term follow-up data, four tested again positive for T1D-related autoantibodies (three positive for IA-2A and one positive for ICA and IAA). Five women were glucose intolerant at the long-term follow-up of which two had IA-2A (one had IFG and one had T1D) and three without autoantibodies. There were no significant differences in long-term characteristics between women with and without autoantibodies postpartum.

CONCLUSIONS

Systematic screening for T1D-related autoantibodies in GDM does not seem warranted since the low positivity rate for autoantibodies in pregnancy and postpartum. At 4.6 years postpartum, five out of 12 women were glucose intolerant but only two still had autoantibodies. In women with clinically significant increased autoantibody levels during pregnancy, postpartum autoantibody re-measurement seems useful since the high risk for further increase of autoantibody levels.

Diabetes: Concepts of β-Cell Organ Dysfunction and Failure Would Lead to Earlier Diagnoses and Prevention

As the world endures a viral pandemic superimposed on a diabetes pandemic, the latter incorporates most of the comorbidities associated with the former, thereby exacerbating risk of death in both. An essential approach to both pandemics is prevention and unrealized earlier treatment. Thus, in this Perspective relating to diabetes, we emphasize a paradigm of, first, reversible β-cell organ dysfunction and then irreversible β-cell organ failure, which directly indicate the potential for earlier prevention, also unrealized in current guidelines. Four pillars support this paradigm: epidemiology, pathophysiology, molecular pathology, and genetics. A substantial worldwide knowledge base defines each pillar and informs a more aggressive preventive approach to most forms of the disorder. This analysis seeks to clarify the temporal and therapeutic relationships between lost β-cell function and content, illuminating the potential for earlier diagnoses and, thus, prevention. We also propose that myriad pathways leading to most forms of diabetes converge at the endoplasmic reticulum, where stress can result in β-cell death and content loss. Finally, genetic and nongenetic origins common to major types of diabetes can inform earlier diagnosis and, potentially, prevention, with the aim of preserving β-cell mass.

Differential gene expression and network-based analyses of the placental transcriptome reveal distinct potential biomarkers for gestationaldiabetes mellitus

AIMS

Gestational diabetes mellitus (GDM) is a common complication during pregnancy affecting the mother and fetus. With the problems encountered with the oral glucose tolerance test (OGTT), we aim to identify potential early biomarkers of GDM.

METHODS

A cross-sectional study was conducted among 80 pregnant women. Blood samples were collected every trimester, and total RNA was isolated. After quality control and library preparation, next-generation sequencing was performed. Differential expression analysis was done. Enriched Gene Ontology: Biological Processes (GO: BP) terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were identified. Gene co-expression networks were constructed. Protein-protein Interaction (PPI) networks were then built from modules significantly correlated with Hemoglobin A1c. Genes with the highest degree of interaction were identified as hub genes.

RESULTS

IGKV2D-28 and PTPRG were consistently differentially expressed among the three comparisons. Top enriched GO: BP terms and KEGG pathways are linked to immune responses. Orange (r = 0.59, p = 0.02) and purple modules (r = 0.41, p = 0.02) of the GDM cohorts in the first and second trimesters, respectively, significantly correlated with Hemoglobin A1c. HDAC8 of the orange module and MPO and CRISP3 of the purple module were identified as hub genes.

CONCLUSIONS

In this study, potential biomarkers of GDM were identified, namely, IGKV2D-28, PTPRG, HDAC8, MPO, and CRISP3.

A case of newly diagnosed autoimmune diabetes in pregnancy presenting after acute onset of diabetic ketoacidosis

Objectives

We present a case of immune-mediated diabetes mellitus, diagnosed in pregnancy upon presentation with diabetic ketoacidosis, found to have normal glucose control postpartum.

Case presentation

A 28-year-old medically uncomplicated G1P0 presented in diabetic ketoacidosis at 28.2 weeks gestation. Workup for pancreatic autoantibodies revealed indeterminate anti-islet cell antibodies and positive anti-glutamic acid antibodies. She was stabilized with intravenous fluids and insulin, and transitioned to long and short acting subcutaneous insulin. Her insulin requirements decreased over the course of her pregnancy. Spontaneous vaginal delivery occurred at 37 weeks. Her postpartum glucose control was normal without re-initiation of insulin.

Conclusions

The diagnosis of diabetic ketoacidosis during pregnancy should prompt further investigation into an underlying diagnosis of immune mediated diabetes. These patients should be followed closely in the postpartum period.

Unveiling the pathophysiology of gestational diabetes: Studies on local and peripheral immune cells

Gestational diabetes mellitus (GDM) has been associated with impaired maternal immune response. Our aim was to review the available literature linking immune cells profile to GDM, in order to comprehend the role that different subpopulations play in the development of this pathology. We searched in PubMed for studies published in the last decade on circulating levels and placenta expression of immune cells on GDM. We identified 18 studies with several differences regarding the study design, clinical characteristics, number of participants, cell subpopulation and type of sample. Most studies assessed only one subpopulation either in peripheral blood or placenta and did not analyse functional properties of the cells. The most frequently evaluated immune cells were T lymphocytes, especially regulatory T (Tregs), and natural killer (NK) cells in the peripheral blood, and placental macrophages. No studies analysing B cells were identified, and only one study each evaluating γδT cells, dendritic cell (DC) and monocytes was found. Although there are controversies, at least one study reported positive association between GDM and CD4⁺ (activated), Tregs, Th17 and γδT cells; neutrophil/lymphocyte; NK cell (cytotoxic); macrophages; and monocytes. The number of studies is still small, so caution should be exercised in interpreting the data, and further research is required to validate these findings and establish the role of adaptive and innate immune cells in GDM pathophysiology.