Low prevalence of maternal microchimerism in peripheral blood of Japanese children with type 1 diabetes

Clinico-Metabolic Profile and Follow-Up of Familial Cases Compared to Sporadic Cases in a Lyon Series of Type 1 Diabetic Children

OBJECTIVE

This study aimed to describe the clinical, biochemical, therapeutic, and progressive characteristics of children with familial type 1 diabetes (T1D) compared to those with non-familial T1D. Compare within the first group, the phenotype of type 1 diabetics inherited from the father with those inherited from the mother.

PATIENTS AND METHODS

We conducted a retrospective study lasting 10 years at the L'hôpital Femme Mère Enfant (Woman-Mother-Child Hospital) in Lyon, France. Cases were any child diagnosed with T1D for at least 12 months who had a parent with T1D. Each case was matched with a T1D control without a family history of T1D, of the same age, same sex and same year of discovery. Cases group was divided into two subgroups according to the sex of the parent with T1D.

RESULTS

A total of 43 children had a TD1 parent (family group) of whom 27 cases were the father. Forty four T1D children without any T1D parent were matched (sporadic group). The family group had consulted earlier (p < 0.001), were less in initial diabetic ketoacidosis (p = 0.016), and had a lower HbA1C level lower (p < 0.001) and lower initial insulin requirements (p < 0.001). During follow-up, it was noted that the evolution of Hb1AC, insulin requirements, and chronic complications were similar in familial and non-familial cases (p = 0.943, p = 0.450, p = 0.664, respectively). The patients in the T1D mother group seemed better balanced than those of the T1D father with an average HbA1C at 10 years of follow-up of 7.82% in the maternal group compared to 9.10% in the paternal group (p = 0.021).

CONCLUSION

This study shows that familial T1D is a protective factor against the initial severity of T1D in offspring. Paternal T1D presents a more severe initial and progressive clinico-biological character than T1D inherited from the mother. However, during follow-up, other psycho-environmental factors could modify this observation.

Maternal type 1 diabetes and relative protection against offspring transmission

Type 1 diabetes is around twice as common in the offspring of men with type 1 diabetes than in the offspring of women with type 1 diabetes, but the reasons for this difference are unclear. This Review summarises the evidence on the rate of transmission of type 1 diabetes to the offspring of affected fathers compared with affected mothers. The findings of nine major studies are presented, describing the magnitude of the effect observed and the relative strengths and weaknesses of these studies. This Review also explores possible underlying mechanisms for this effect, such as genetic mechanisms (eg, the selective loss of fetuses with high-risk genes in mothers with type 1 diabetes, preferential transmission of susceptibility genes from fathers, and parent-of-origin effects influencing gene expression), environmental exposures (eg, exposure to maternal hyperglycaemia, exogenous insulin exposure, and transplacental antibody transfer), and maternal microchimerism. Understanding why type 1 diabetes is more common in the offspring of men versus women with type 1 diabetes will help in the identification of individuals at high risk of the disease and can pave the way in the development of interventions that mimic the protective elements of maternal type 1 diabetes to reduce the risk of disease in individuals at high risk.

Glutamic Acid Decarboxylase and Tyrosine Phosphatase-Related Islet Antigen-2 Positivity among Children and Adolescents with Diabetes in Korea

Autoantibodies against glutamic acid decarboxylase (GADA), tyrosine phosphatase-related islet antigen 2 (IA2A), insulin (INSA), and islet cells (ICA) are critical for determining the type of diabetes and management strategy in new-onset diabetes mellitus (NODM), but there have been few reports of all diabetes-associated autoantibody (DAA) in Korea. We retrospectively analyzed 193 patients with NODM aged 0 to 18 years who were followed at two tertiary centers in Korea (2017 to 2021). Patients with type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM) were 93 (48.2%) and 100 (51.8%), respectively. In T1DM patients, the DAA positivity rate was 94.6%; prevalence of GADA, IA2A, INSA, and ICA was 71.0%, 71.0%, 31.2%, and 10.8%, respectively; and IA2A added 10.7% point autoantibody positivity (83.9% for GADA+INSA+ICA and 94.6% for GADA+INSA+ICA+IA2A). Among the patients with T2DM, 12 (12.0%) were positive for DAA, and all were positive for INSA. These findings suggest that DAA at diagnosis, especially GADA and IA2A, is useful for classifying diabetes in Korean children and adolescents.

Quantification of Maternal Microchimeric Cells in the Liver of Children With Biliary Atresia

ABSTRACT

Biliary atresia (BA) is a rare disorder of unknown etiology. There is a debate as to whether maternal microchimerism plays a significant role in the development of BA or in graft tolerance after liver transplantation. Here, we performed quantitative-PCR-based assays for liver tissues of children with BA and other diseases. Maternal cells were detected in 4/13 and 1/3 of the BA and control groups, respectively. The estimated number of maternal cells ranged between 0 and 34.7 per 106 total cells. The frequency and severity of maternal microchimerism were similar between the BA and control groups, and between patients with and without acute rejection of maternal grafts. These results highlight the high frequency of maternal microchimerism in the liver. This study provides no evidence for roles of microchimerism in the etiology of BA or in graft tolerance. Thus, the biological consequences of maternal microchimerism need to be clarified in future studies.