Introduction: Cytokines, chemokines, acute phase proteins (APP), adipocytokines and matrix metalloproteinases (MMP) are involved in different pathophysiological processes of inflammatory character. The role of the different immune markers and the peripheral immunoregulatory milieu in children diagnosed with type 1 diabetes (T1D) in combination with celiac disease (CD) is not fully understood and is not well studied. The purpose of the present study was therefore to acquire more knowledge and to gain deeper understanding on peripheral immunoregulatory milieu in children with T1D and/or CD.

Methods: The study included children diagnosed with T1D in combination with CD (n=18), children with T1D (n=27) or CD (n=16), and reference children (n=42).

Blood samples were collected, and serum stored in -80°C until analysis, avoiding multiple freeze-thaw cycles. The inflammatory cyto/chemokines (IL-1β, -5, -6, -8, -9, -10, -13, -15, -17A, -22, -25, -33, IFN-γ, TNF-α, G-CSF, MCP-1, MIP-1α, MIP-1β), diabetes related immune markers (visfatin, resistin), APP (procalcitonin (PTC), ferritin, tissue protein activator, fibrinogen, serum amyloid A) and matrix metalloproteinases (MMP-1, -2, -3) were analyzed with Luminex technique using Bio-Plex assays. Hierarchical cluster analysis was used to identify similarities/differences in immune profiles between children with double diagnosis and children with single diagnosis and reference children. Mann-Whitney U test was used for comparison of the different diagnosis groups within the clusters and whole cohort, respectively.

Results: The largest cluster included 75% of the participants and the diagnose distribution in the cluster were very similar to the distribution in the whole study cohort. The remaining 25% were divided in two smaller clusters representing 15.5% and 6.5% respectively. The major finding of this study showed that children with double diagnosis had (1) lower serum levels of IL-22, MCP-1, PCT, visfatin and MMP-2 compared to children with T1D; and (2) lower serum levels of the APC associated chemokine MIP-1α compared to reference children, observed in the main cluster. Most of these observations were also seen in the whole cohort.  

Conclusion: Our observations indicate decreased serum levels of IL-22, MIP-1α, MCP-1, PCT, visfatin and MMP-2 in children diagnosed with T1D in combination with CD. These results indicate a suppressed immune profile including Th17 cytokines, chemokines, acute phase proteins, diabetes-related and matrix metalloproteinase immune markers. Functional studies of the involved immune cells (CD4⁺ Treg, CD8⁺ Treg, NK-cells and dendritic cells) could contribute to elucidate the heterogeneous immunological processes in children with more than one autoimmune disease.