Objectives: This study investigates the potential for using Toll-like receptor 4 (TLR4) messenger RNA expressions in the oral mucosa of Behcet's disease (BD) as a disease activity marker.
Methods: 53 buccal mucosal brush biopsies were collected after informed consent from 40 BD patients in both active and quiescent forms of the disease (F/M: 26/14, mean age: 43.8 +/- 10.5 years). Simultaneously, 21 samples were collected from age and sex matched healthy volunteers (HV). Total RNA and protein were purified and checked by real time PCR and Western blot for the presence of the TLR2, TLR4 messenger RNA and protein.
Results: Mean values and standard deviations of the relative expression of TLR2 messenger RNA were as following; 1.408e-006 (SD: 2.826e-006), 5.574e-005 (SD: 2.535e-004), 3.586e-006 (SD: 1.403e-005) and 2.010e-004 (SD: 1.269e-004) in HV, all BD, quiescent BD and active BD respectively.
Mean values and standard deviations of the relative expression of TLR4 messenger RNA were as following; 2.502e-006 (SD: 5.040e-006), 3.745 (SD: 5.106e-005), 1.042e-005 (SD: 5.106e-005) and 1.389e-003 (SD: 4.330e-003) in HV, all BD, inactive BD and active BD respectively.
One way analysis of variance test showed p value of 0.0054 when comparing the eight different groups.
Conclusion: TLR2 and TLR4 messenger RNA expression was greater in the buccal mucosa from BD patients than in matching HV during the active phase of the disease. Moreover, expression of both TLR2 and TLR4 was greater in buccal mucosa from active BD than in those with quiescent disease. The level of expression of TLR4 appeared higher than TLR2 in active BD patients but failed to reach statistical significance. Therefore, both receptors might be useful as disease activity markers. However, TLR2 and TLR4 cannot be used as diagnostic markers.