ESPE Abstracts

Background: Type 1 DM (T1DM) is a chronic condition characterized by persistent hyperglycemia; which can impair immunity and increase susceptibility to infections. Latent TB infection (LTBI) is a subclinical infection caused by Myobactaeria tuberculosis antigens without clinical, bacteriological or radiological evidence of manifest TB disease. Tuberculin test (TST) is an inexpensive test used to identify LTBI status, but has limitations. False positive TST can occur due to BCG vaccination. Interferon gamma release assays (IGRA) can also be used to detect LTBI. Previous studies suggested an association between DM and LTBI. Furthermore, diabetic patients with untreated LTBI were shown to be more likely to progress to active TB disease. However, there is no consensus on the standard screening test for LTBI in T1DM.

Aim of the work: To determine the most preferred screening method for LTBI in T1DM children, in addition to confirming the association between LTBI and T1DM in children and its effect on glycemic control.

Methods: This cross-sectional study included 81 T1DM children aged 1-18 years, following up at Zagazig University Pediatric Hospital. They were compared to 81 healthy children as a control group. All patients were subjected to detailed history taking, and clinical examination with emphasis on BCG scar and chest examination. Investigations were done to all patients including HbA1C, TST using Mantoux technique, and chest X-ray. An induration of ≥10 mm was used as a cut-off to determine TST positivity. Quantiferon test was done to patients with positive TST.

Results: The mean age of patients at enrollment was 10.90±4.47 years. The mean duration of DM was 3.3±3.02 years. The percentage of positive TST was higher among T1DM patients than control group (32.1% vs 7.4%) (P<0.001). There was no statistically significant difference between positive and negative TST regarding age, sex, and duration of DM. However, there was a statistically significant increase in HbA1C among T1DM patients with positive TST than those with negative results (7.88 vs 7.42%) (P<0.001). Moreover, 40% of T1DM patients with positive TST had positive Quantiferon test confirming LTBI in 12.8% of patients.

Conclusion: T1DM patients are more likely to have positive TST than the control group. Patients with T1DM and LTBI had higher HbA1C. Quantiferon test-in addition to TST- is a preferred method to screen for LTBI than TST alone. More studies are required to detect the ideal method of LTBI screening in T1DM especially in countries with high incidence of TB.