Next- generation sequencing is an effective method for diagnosing patients with different forms of monogenic diabetes

AIM

Monogenic diabetes (MD) represents 5-7% of antibody-negative diabetes cases and is a heterogeneous group of disorders.

METHODS

We used targeted next-generation sequencing (NGS) on Illumina NextSeq 550 platform involving the SureSelect assay to perform genetic and clinical characteristics of a study group of 684 individuals, including 542 patients referred from 12 Polish Diabetes Centers with suspected MD diagnosed between December 2016 and December 2019 and their 142 family members (FM).

RESULTS

In 198 probands (36.5%) and 66 FM (46.5%) heterozygous causative variants were confirmed in 11 different MD-related genes, including 31 novel mutations, with the highest number in the GCK gene (206/264), 22/264 in the HNF1A gene and 8/264 in the KCNJ11 gene. Of the 183 probands with MODY1-5 diabetes, 48.6% of them were diagnosed at the pre-diabetes stage and most of them (68.7%) were on diet only at the time of genetic diagnosis, while 31.3% were additionally treated with oral hypoglycaemic drugs and/or insulin.

CONCLUSIONS

In summary, the results obtained confirm the efficacy of targeted NGS method in the molecular diagnosis of patients with suspected MD and broaden the spectrum of new causal variants, while updating our knowledge of the clinical features of patients defined as having MD.

Updated 24-year trend of Type 1 diabetes incidence in children in Poland reveals a sinusoidal pattern and sustained increase

AIMS

To present the incidence trend for Type 1 diabetes in Polish children aged 0-14 years, updated using data collected during 2005-2012, and assess the reliability of the predictive model constructed previously using the 1989-2004 database.

METHODS

Children aged < 15 years with newly diagnosed Type 1 diabetes are recorded prospectively (EURODIAB criteria) in several regional registers in Poland. Age- and gender-standardized incidence rates for Type 1 diabetes were calculated per 100 000 persons/year. Incidence rates were analysed in terms of the dependency on age, gender, geographical region and population density. Incidence rate trends over time were modelled using generalized linear models.

RESULTS

The mean standardized incidence for 1989-2012 was 12.72 per 100 000 persons/year [95% confidence interval (CI), 11.35 to 14.21]. Over the 24-year observation period, the incidence increased from 5.36 to 22.74 per 100 000 persons/year. The lowest incidence rate was in children aged 0-4 years (8.35, 95% CI 7.27 to 9.57 per 100 000 persons/year). There was no difference between genders, or urban and rural regions. Incidence rates were higher in northern compared with southern Poland [14.04 (95% CI 12.59 to 15.63) vs. 11.94 (95% CI 10.62 to 13.39) per 100 000 persons/year]. The new data corrected the earlier predictive model by changing the estimates of some factors related to patient age, gender and their interactions with the remaining factors. The incidence rate shows periodic 5.33-year fluctuations. The periodicity component allows for a more accurate prediction of the incidence rate over time.

CONCLUSIONS

This cohort study reveals a sustained increase in Type 1 diabetes incidence in Polish children aged 0-14 years with regular, sinusoidal fluctuations and a slight levelling off in past few years. It is of concern that are the highest increases in incidence are found in children aged 0-4 years.

Endothelial progenitor cell levels in juvenile idiopathic arthritis patients: effects of anti-inflammatory therapies

BACKGROUND

Juvenile idiopathic arthritis (JIA), similarly to other arthritides, can be associated with damage of endothelial layer of which structure and function is dependent on reparative properties of endothelial progenitor cells (EPC). To date, it remained unknown whether EPC numbers are altered in young JIA patients and whether on-going anti-inflammatory therapies could exert positive effects on these progenitor cells.

METHODS

We performed a quantitative analysis of EPC numbers in 25 patients diagnosed with JIA according to International League of Associations for Rheumatism (ILAR) criteria [age 11.50 (7.50-15.00) years] in a broad context of inflammatory and cardiovascular parameters as well as different types of anti-inflammatory treatments. 11 healthy children [age 13.00 (11.00-14.00) years] were recruited as a control group.

RESULTS

We demonstrated that EPC numbers were similar in JIA patients and control subjects (0.02% vs. 0.05%, respectively, p = 0.37). EPC levels in JIA patients were negatively correlated with index of insulin resistance (rho = -0.458, p = 0.021), endogenous insulin (rho = -0.472, p = 0.017), triglyceride (rho = -0.438, p = 0.029) and TNF-alpha levels (rho = -0.446, p = 0.026). Notably, glucocorticoid (GC) therapy, was associated with detection of decreased EPC levels in JIA patients (p = 0.023). In contrast, methothrexate (MTX) and etanercept therapy in JIA patients did not affect EPC levels (p = 0.92 and p = 0.08, respectively).

CONCLUSIONS

We found that EPC numbers are maintained at normal levels in JIA patients and are not enhanced by disease-specific anti-inflammatory treatments.