Table 3.
The role of DPP4 in autoimmune diseases.
| Expression | Mechanisms | Effect of DPP4 inhibitor on disease phenotype | |
|---|---|---|---|
| RA | Decreased in serum (101) | Limit the recruitment of inflammatory cells (109, 110) Involved in bone erosion (114) |
Inconsistent: several case reports indicate DPP4 inhibitors induce RA (117, 126), some studies reported no association or reduced risk of RA (120) |
| SLE | Decreased in serum (4, 123, 124) | Evidence limited | Reduce risk (126) |
| SSc | Increased in T cells (129) | Indication of activated fibroblast | Limited evidence in humans; Animal study shows DPP4 inhibition meliorates fibrosis in vivo ( 91, 137) |
| IBD | Decreased serum activity (140, 165) | Regulate neuroimmune response (145) Impair tissue recovery by inactivation of GLP-2 (147) |
Biomarker for treatment response (143) DPP4i promote prognosis in animals (149) Increased IBD risks (150, 151), or no impact (152, 153) |
| SS | Increased in saliva (166) | Regulate expression of MMP9 (166) | Evidence limited |
| OA | No significant alteration (167) | Upregulate AGE-induced MMPs (168) Promote bone formation by inactivating GLP-1 (168) |
Improve ECM loss (168, 169) |
| Psoriasis | Increased at mRNA level in lesion (170) | inhibit T cell activation (171) | Improve psoriasis severity (172) |