Francesco Chiappelli Ph.D
Hepatitis C (HepC) infection places people at increased risk of developing lichen planus (LP), including in the oral cavity (oral lichen planus, OLP), but the association varies in different regions of the world, with people from the United States among the groups at highest risk.
Limited evidence suggests an association between HepC seroprevalence in patients with LP as well as the prevalence of LP in patients with HepC infection.
In patients with Hep C infection, is there an increased prevalence of LP diagnoses, compared to patients without the HepC seropositive status?, and conversely is LP prevalence increased in HepC seropositive patients, compared to those without HepC infection?
The authors examined five search engines. Only observational studies of patients with HepC seropositivity in which there was a comparison/control group were included. Studies were excluded if there was a potential that the LP patients were co-infected with HepC. All languages were included. Two independent screeners determined eligibility of the reports. A third reviewer resolved any disagreements. The authors assessed risk of bias (Yes, No, Unclear) according to random patient sampling, matching of the control group, and design (prospective vs. retrospective). Low bias risk studies satisfied all the criteria; high bias risk studies failed to satisfy one or more criterion. Selected studies included subjects and control groups positive for HepC among patients with LP, or those positive for LP among HepC seropositive patients. The authors calculated odds ratio (OR), with 95% confidence intervals (CI95). The authors tested heterogeneity and publication bias, and interpreted meta-analysis results with the fixed effect model.
Lichen planus (LP) leads to an increased risk (OR: 4.85, CI95: 3.58-6.56) of being HepC seropositive, and HepC seropositive patients are at increased risk of LP (OR: 4.47, CI95: 1.84-10.86). Risk ratios vary in different geographical regions: the risk of LP is higher among HepC seropositive patients than controls in Southern Europe (OR: 4.26, CI95: 1.13–16.10) and the United States (OR: 5.09; CI95: 1.33–19.41). Risk ratio of HepC seropositivity among patients with LP younger than 50 is significantly greater than in age-matched controls (OR: 3.43, CI95: 2.02–5.85).
HepC seropositivity increases the risk for LP, particularly among subjects younger than 50 years of age, and the risk of LP varies in different regions of the world, being higher among HepC seropositive patients than controls in the Mediterranean basin and in the United States.
Source of Funding:
Importance and Context:
Lichen planus is a relatively common disorder of the stratified squamous epithelia. It frequently involves the oral cavity (OLP). A chronic condition that primarily affects peri/post-menopausal women, OLP may be pre-malignant. There is no cure for OLP; only palliative treatment for the more severe OLP lesions. With regard to hepatitis, most HepC seropositive patients are not aware of their HepC infection. Chronic HepC infection can lead to cirrhosis and hepatocellular carcinoma. Increased health literacy about HepC and LP will contribute to improve the patients’quality of life.
Strengths and Weaknesses of the Systematic Review:
The study has sound research synthesis protocol for obtaining the sample of studies and doing the preliminary screening. The authors present adequate transformation of the data to odds ratio and CI, and stringent meta-analysis and related tests of homogeneity and publication bias. The ratings of risk bias, which the authors term “quality”, and the ratings of the dimension the authors refer to as global validity are weak ad-hoc measures, with no validation data. The ORs were not significantly different when studies were excluded from the meta-analysis, based on the authors’ global validity scale.
Strengths and Weaknesses of the Evidence:
The evidence of association between HepC and LP is significant. Even when studies with high and moderate risk of bias are excluded from the meta-analysis, the outcomes show statistical significance. The clinical question does not lend itself to randomized clinical trials; therefore, the types of studies selected, while not having the optimally higher level of evidence, are the strongest we have to determine association, but cannot but yield the overall limited evidence of this systematic review. The assessment of the quality of the evidence (i.e., risk bias) was not validated satisfactorily; and this contributes to the overall limited evidence.
Implications for Dental Practice:
There is a strong link between the presence of OLP and HepC seropositivity, but most patients with HepC are asymptomatic. Dentists may be able to alert OLP patients to a potential for HepC infection. Early diagnosis and a proper management of HepC seropositivity and OLP might save lives and reduce health care costs.