Objective: To compare the level of expression of the gene CTSL and its correlation with NKT cells in patients with recent-onset type 1 diabetes (T1D), their siblings, and healthy controls.
Methods: Analytical cross-sectional design. Patients with T1D < 3 months evolution, their siblings, and healthy controls were included. Percentages and absolute numbers of NKT cells were measured with expression of the CTSL gene.
Results: 124 subjects: with T1D (n = 48), siblings (n = 44) and controls (n = 32) were included. HbA1c was greater and C-peptide lower in T1D than the other groups and sibling age was higher (p < 0.001). There were no differences in NKT cells between T1D (0.176 ± 0.202) and controls (0.118 ± 0.133), but the percentage was higher in siblings (0.246 ± 0.188; p = 0.002). Lower level of expression of the CTSL gene associated with both absolute number (r: 0.4607; 95% CI: -0.08425 to -0.7935; p = 0.043) and percentage of NKT cells (r: 0.4540; 95% CI: -0.0927 to -0.7903; p = 0.045) in the T1D group.
Conclusions: Patients with T1D have lower percentage and absolute number of NKT cells compared to their siblings. NKT cells absolute numbers are correlated with the expression of CTSL in T1D patients.