HLA-C/KIR genotypes in oral lichen planus patients infected or non-infected with hepatitis C virus

Bidirectional Association between Lichen Planus and Hepatitis C-An Update Systematic Review and Meta-Analysis

Lichen planus (LP) is a chronic, inflammatory mucocutaneous disorder associated with systemic diseases such as hepatitis C (HCV). The objective of this study is to evaluate the association between LP and HCV bidirectionally through a systematic review and meta-analysis. A comprehensive search of studies published was performed in the databases of PubMed, Embase, and Web of Science. Out of 18,491 articles, 192 studies were included. The global prevalence of HCV positive (HCV+) in LP patients registered from 143 studies was 9.42% [95% confidence interval (CI), 7.27-11.58%], and from these, 84 studies showed HCV+ 4-fold more frequent in LP than a control group (OR, 4.48; 95% CI, 3.48-5.77). The global prevalence of LP in patients HCV+ recorded from 49 studies was 7.05% (95% CI, 4.85-9.26%), and from these, 15 registered a 3-fold more LP in HCV (OR, 3.65; 95% CI, 2.14-6.24). HCV+ in LP patients showed great geographic variability (OR, 2.7 to 8.57), and the predominantly cutaneous location was higher (OR, 5.95) than the oral location (OR, 3.49). LP in HCV+ patients was more frequent in the Eastern Mediterranean (OR, 5.51; 95% CI, 1.40-15.57). There is a higher prevalence of HCV+ in LP and vice versa than in the control group, especially in certain geographical areas that should be taken into consideration when doing screening in countries with an upper prevalence of HCV among the general population.

Association between hepatitis C infection in Thai patients with oral lichen planus: A case-control study

AIM

The aim of the present study was to investigate the prevalence of hepatitis C virus (HCV) infection and evaluate liver enzyme levels in patients from upper northern Thailand with oral lichen planus (OLP).

METHODS

A case-control study of 101 patients with OLP and 101 patients without OLP was conducted. Peripheral blood was taken from each patient and screened for anti-HCV antibody using immunochromatography. Positive samples were further confirmed using chemiluminescent microparticle immunoassay (CMIA) and reverse transcription-polymerase chain reaction. In addition, liver enzyme levels, alanine transaminase, aspartate transaminase, and alkaline phosphatase were evaluated using spectrophotometry.

RESULTS

Immunochromatography and CMIA revealed that nine patients with OLP (8.9%) were positive for anti-HCV antibodies, whereas only one patient without OLP was HCV positive (odds ratio = 9.78). All patients who were HCV positive had significantly higher liver enzyme levels than patients who were HCV negative.

CONCLUSIONS

The results of the present study indicated that OLP in certain patients was significantly associated with HCV. This could warrant screening for HCV-infected patients with OLP in Thailand.

A potential peptide pathway from viruses to oral lichen planus

Oral lichen planus is an idiopathic inflammatory disease of oral mucous membranes, characterized by an autoimmune epidermis attack by T cells. It remains unknown, however, how such aggressive T cells are activated in vivo to cause epidermal damage. This study analyzes the relationship at the peptide level between viruses and oral lichen planus disease. Four potentially immunogenic peptides (SSSSSSS, QEQLEKA, LLLLLLA, and MLSGNAG) are found to be shared between HCV, EBV, HHV-7, HSV-1, and CMV and three human proteins (namely pinin, desmoglein-3, and plectin). The described peptide sharing might be of help in deciphering the still unexplained immunopathogenic pathway that leads to oral lichen planus.

Oral lichen planus: focus on etiopathogenesis

Lichen planus is a chronic mucocutaneous inflammatory disease, which frequently affects the oral mucosa of white females over 40 years old. Its aetiology remains uncertain and the pathogenesis is still the object of much speculation. The present paper presents the most well known antigens, and describes the action of different cells and proteins associated with the development of that disease, as well as the possible agents involved with its malignant transformation. Different external agents, especially virus, and internal agents, like stress, and the heat shock protein antigen expression, associated or not, can alter the basal keratinocytes of the oral mucosa making them susceptible to apoptosis by CD8(+) cytotoxic T cell as well as activate matrix metalloproteinase and mast cell degranulation, which produce a great range of inflammatory mediators and cytokines determining the clinical onset of the disease. Regarding carcinogenesis, since it is a complex process and presents multifactorial origin, it is believed that there may be a synergism between intrinsic, such as inflammation mediators, and extrinsic agents (tobacco, alcohol, viral infections) for the OLP malignant transformation to occur. However, further studies are needed to better understand the origin, pathogenesis and process of malignant transformation of OLP.

Emerging role for the killer-cell immunoglobulin-like receptors genotype, in the susceptibility of skin diseases

NK cells are a major group of immune cells responsible for the phenomenon of natural, innate cytotoxicity. One of the better studied receptors of human NK cells are killer cell immunoglobulin-like receptors (KIR) responsible for checking the presence of MHC class I molecules, which serve as their ligands. Although previously treated as specific for NK cells, nowadays these receptors are known to also occur on T cells. Genetics of KIR molecules is very complicated, what create a great variability of haplotypes in various populations world-wide. In addition, some KIR are known to recognize HLA-C (epitopes C1 or C2), HLA-B (Bw4) or HLA-A (A3 and/or A11) molecules. Therefore, this makes a huge diversity of reactions among individuals, depending on the presence or absence of given KIR and their ligands, hence differential susceptibility to several diseases, including various dermatoses. This paper underlines the important role of both KIR genotypes and HLA class I genes with reference to the various skin diseases.