Study Year of
publication 		Study design Sample size Gender distribution Age
(years) 		Type of oral lesions Diagnostic context Type of IF Specific antibodies used
Lee [27] 2016 Retrospective study 52 patients 18 males,
34 females 		11 to 80 OLP and OLL Evaluate differences in final diagnosis of OLP and OLL based on different diagnostic criteria, and compare DIF findings between OLP and OLL DIF Fibrinogen
Zhou et al. [28] 2016 Single-center retrospective study 33 patients with pemphigus.
Control: 61 		11 males, 22 females. Control: 23 males 38 females 50 (SD 10.4).
Control: 58.5 (SD 12.7) 		Chronic erosions, blistering, exudation of oral mucosa Differential diagnosis of pemphigus from pemphigoid, DLE, erosive lichen planus IIF IgG autoantibodies against keratinocyte cell surfaces
Masquijo-Bisio et al. [29] 2017 Observational study 85 cases Male : female ratio:
4.25 : 1 reticular OLP,
1.72 : 1 plaque like OLP,
0.8 : 1 leukoplakia 		19 to 83 Plaque-type OLP, homogenous leukoplakia Differentiation between plaque-type OLP and homogenous leukoplakia DIF Anti-fibrinogen antibody
Yamanaka et al. [30] 2018 Prospective, cross-sectional study 110 patients 26 males, 84 females 19 to 87 Reticular lesions mainly on the buccal mucosa Differentiation of OLP and OLL DIF Fibrinogen, IgM, IgA, IgG, C3
Abdalla et al. [31] 2017 Cross-sectional study 61 patients - - Fibroepithelial polyp, low-grade dysplasia, high-grade dysplasia, T1 OSCC, T4 OSCC Assessing expression of epithelial and pro-invasive markers in oral dysplasia and OSCC Quantitative IF Fully characterized antibodies for E-cadherin, EMP1, 5T4, N-cadherin
Kamaguchi et al. [32] 2018 Prospective study 7 cases - 51 to 85 Gingival lesions in all 7 patients; buccal lesions in 1 of the 7 patients Diagnosis of MMP DIF using non-lesional buccal mucosa IgG and C3
Bresler et al. [33] 2020 Retrospective study 148 cases 45 males, 103 females Mean 56 DG, oral ulcers, overlap with OLP Suspected oral autoimmune bullous disorders DIF Not specified
Reyes et al. [34] 2020 Observational study Not detailed - - Oral dysplasia Diagnosis and progression of oral dysplasia to OSCC Tissue IF analysis Antibodies against β-catenin, GSK3β, Axin, APC, EEA1, Rab5
Tikkhanarak et al. [35] 2019 Retrospective study 53 patients"
17 OLP,
19 OLL,
17 OLDR 		Male : female ratio:
14 : 3 OLP,
17 : 2 OLL,
15 : 2 OLDR 		OLP: 41.9 (SD 14.4),
OLL: 48.9 (SD 16.5),
OLDR: 61.6 (SD 6.1) 		Red and white lesions Differentiating OLP, OLL, and OLDR DIF IgM, IgA, C3, IgG
Noormohammadpour et al. [36] 2020 Prospective 68 patients 30 males, 38 females 17 to 91 Erosive/ulcerated oral lesions PV vs. other causes of erosive oral lesions DIF IgG/C3
Gupta et al. [37] 2021 Cross-sectional study 105 cases (45 OSF patients,
30 healthy controls with areca nut chewing habit, 30 healthy controls without areca nut chewing habit) 		- - OSF Detection of ANAs in OSF patients and healthy controls IIF ANAs
Hanna et al. [38] 2021 Retrospective study 58 patients 26 males, 32 females 27 to 79 Oral leukoplakia categorized into localized leukoplakia and proliferative leukoplakia. Included various degrees of dysplasia: mild, moderate, or severe MIF nCounter® PanCancer IO 360™ Panel (NanoString Technologies, Inc., Seattle, WA, USA) for gene expression profiling. MIF was used to analyse immune cell populations, including CD8+ T cells and T regulatory (Treg) cells
Petruzzi et al. [39] 2022 Retrospective cohort study 22 patients with oral pemphigus,
64 controls 		22 males, 64 females Mean 59.5 Oral erosions characteristic of PV Patients with clinical diagnosis of oral pemphigus referred to a tertiary care center IIF Anti-desmoglein 1 (Dsg1) and anti-desmoglein 3 (Dsg3)
Rujitharanawong et al. [40] 2022 Retrospective 147 patients 36 males, 111 females 49.9 (SD 14.5) Not specified, but included oral and cutaneous lichen planus Confirmed diagnosis of lichen planus based on clinical and histopathological criteria DIF IgM, IgG, fibrin, C3
He et al. [41] 2021 Diagnostic accuracy study 81 patients:
41 with PV and 40 with non-pemphigus vulgaris 		16 males, 25 females 53.8 (SD 10.47) PV Evaluation of diagnostic efficacy of DIF analysis of oral Tzanck smears in clinical practice DIF IgG, C3, IgA, IgM
Mao et al. [42] 2022 Prospective study 42 patients with suspected OLP lesions. Control: 47 OLP: 16 males, 26 females.
Control: 35 males, 12 females 		OLP: 39.6 (SD 13.7), control: 48.1 (SD 12) OLP Evaluation of the diagnostic value of DIF and investigation of immune functions in OLP DIF It did not provide details on the specific antibodies used for the DIF analysis
Hansen et al. [43] 2023 Retrospective study 132 patients 36 males, 96 females 61.9 (SD 13.8) OLP Patients had a clinical or working diagnosis of OLP indicated by the submitting clinician on the biopsy request form DIF Not detailed
Korkitpoonpol et al. [44] 2023 Retrospective study 136 patients 21 males, 115 females 19 to 86 OLP, OLL, OED Differentiating among OLP, OLL, and OED based on clinical presentations DIF Not reported

ACIF = anti-complement immunofluorescence; ANA = antinuclear antibody; BMZ = basement membrane zone; C3 = complement component 3; DIF = direct immunofluorescence; DLE = discoid lupus erythematosus; DG = desquamative gingivitis; FITC = fluorescein isothiocyanate; H&E = hematoxylin and eosin; IIF = indirect immunofluorescence; IgG = immunoglobulin G; IgA = immunoglobulin A; IgM = immunoglobulin M; LE = lupus erythematosus; MIF = multiplexed immunofluorescence; MMO = maximum mouth opening; OLDR = oral lichenoid dysplasia; OLL = oral lichenoid lesions; OLP = oral lichen planus; OMLP = oral mucosal lichen planus; OSCC = oral squamous cell carcinoma; OSF = oral submucous fibrosis; PV = pemphigus vulgaris; RAS = recurrent aphthous stomatitis; T1 = tumour size classification (smallest); T4 = tumour size classification (largest); WHO = world health organization; IF = immunofluorescence.