Association between oral lichen planus and Hashimoto thyroiditis: A systematic review

Association Between Autoimmune Thyroid disease and Oral Lichen Planus: A Multi-Omic Genetic Analysis

OBJECTIVE

The oral mucosa mirrors a range of latent systemic disorders, with potential clinical associations noted between autoimmune thyroid disease (AITD) and oral lichen planus (OLP). This study aims to explore the genetic relationship and underlying mechanisms mediating these conditions.

METHODS

A 2-step Mendelian randomization (MR) analysis was conducted to elucidate the genetic relationship and mediating factors between AITD and OLP. Linkage disequilibrium score regression was employed to assess heritability and genetic correlations among phenotypes, followed by genetic colocalization analysis to discern shared genetic variants. A transcriptome-wide association study (TWAS) was also performed to pinpoint gene expression profiles.

RESULTS

Genetically predicted AITD is associated with an increased risk of OLP (OR[95% CI]: 1.44[1.19,1.74], P=1.61 × 10-4), potentially mediated by hypothyroidism. There is strong evidence of colocalization between AITD and OLP, with a shared PTPN22 gene variant driving this association. TWAS further identified RNASET2 and FGFR1OP within the HLA region as high-confidence shared genes for both conditions.

CONCLUSION

Our study provides novel evidence of a possible genetic association between AITD and OLP. These findings highlight the critical role of endocrine alterations in maintaining oral immune homeostasis, though further research is warranted to validate our findings.

Laboratory investigation of the association between oral lichen planus and Hashimoto's thyroiditis

BACKGROUND

Previous studies have shown some relationship between oral lichen planus (OLP) and certain systemic comorbidities. The aim of this study was to investigate laboratory parameters between cases of Hashimoto's thyroiditis (HT) concomitant with OLP and cases of HT only.

METHODS

This case-control study comprised 59 HT patients with OLP and 76 without OLP, all of whom had 5 serum thyroid-related indicators, including thyroid peroxidase antibody (TPOAb), thyroglobulin antibody (TGAb), thyroid stimulating hormone (TSH), free triiodothyronine (FT3), and free thyroxine (FT4).

RESULTS

Compared to cases of HT only, female predominance, presence of thyroid nodules, positive TGAb, and higher FT3/FT4 ratio were mainly observed in cases of HT concomitant with OLP (all P < 0.05). Multivariate regression analysis revealed that presence of thyroid nodules (odds ratio [OR], 10.328; 95% confidence interval [CI], 2.564-41.604), positive TGAb (OR, 6.936; 95%CI, 2.024-23.765), and higher FT3/FT4 ratio (OR, 2.577; 95%CI, 1.377-4.823) were associated significantly (all P < 0.005) with higher risk of OLP occurrence in 135 HT patients. Notably, these significant associations were not found among 30 male patients but did among 105 female patients in regression analysis.

CONCLUSION

This retrospective study revealed that presence of thyroid nodule, positive TGAb, and high FT3/FT4 ratio as risk factors were significantly associated with OLP occurrence risk in female patients with HT. This suggests that female patients suffering from HT, particularly who presented with the risk factors, should be informed about the risk of OLP development and the need for oral mucosal examination to screen for lichen lesions.

Possible interplay of diabetes mellitus and thyroid diseases in oral lichen planus: A pooled prevalence analysis

The existence of a comorbidity between diabetes mellitus (DM) as well as between thyroid diseases (TD) and oral lichen planus (OLP), respectively, was substantially demonstrated. However, there is not enough attention to the concurrent status of both TD and DM in OLP patients. Herein, this short communication aimed to compare 1) the prevalence of DM when TD was concurrently investigated and that of DM when TD status was ignored; 2) the prevalence of TD when DM was concurrently investigated and that of TD when DM status was ignored in the studies. The pooled prevalence (9.86 %; 95 % confidence intervals [CI], 9.22-10.53 %) of DM when TD was concurrently investigated was significantly higher than that (8.13 %; 95%CI, 8.03-9.12 %) when TD status was not investigated in OLP patients. The pooled prevalence (12.48 %; 95%CI, 11.77-13.22 %) of TD when DM was concurrently investigated was significantly higher than that (10.45 %; 95%CI, 9.52-11.46 %) when DM status was not investigated in OLP patients. Thus, it is logical to presume for the first time that there is possible interplay of DM and TD in OLP occurrence. TD and DM should serve as important confounding factors each other in clinical investigation on OLP and associated comorbidities.