Objective: To investigate the relationship between coxsackievirus infection and type 1 diabetes mellitus (T1DM), and observe the changes of T lymphocyte subsets in the development of T1DM.
Methods: We detected Coxsackievirus RNA by reverse transcription PCR, and measured the change in T-lymphocyte subsets by flow cytometry in 22 cases of newly diagnosed T1DM (group I), 30 patients with diabetes for some time (group II), and 30 healthy subjects (group III).
Results: The positivity rate of coxsackie virus RNA in groups I, II, and III was 55.55%, 23.33%, and 6.67%, respectively, showing a significant difference among the 3 groups (P<0.01). Patients with upper respiratory tract infection had a higher positivity rate for coxsackie virus RNA than those without upper respiratory tract infection in group I (P<0.05). Compared with the control group, the percentage of CD3, CD4 and CD4/CD8 ratio decreased significantly in groups I and II (P<0.01 or P<0.05). CD3, CD4 and CD4/CD8 tended to increase in group II in comparison with group I, and there was an significant difference in CD3 and CD4 between the two groups (P<0.01 or P<0.05). Compared with the control group and CVBRNA-negative group, CVBRNA-positive group showed significantly lowered CD3, CD4, CD8 and CD4/CD8 (P<0.01 or P<0.05).
Conclusion: The occurrence and development of type 1 diabetes is closely related to coxsackie virus infection, and the changes in T lymphocyte subsets serves as a probable mechanism of its pathogenicity.