The Relationship Between Human Herpesvirus 7 And The Pathogenesis Of Lichen Planus

Background : LP, of which pathogenesis is unclear, is a kind of self-limited disease. Up to the present day, the definit cause and pathogenesis of LP are not totally found out. The researches in the past showed that immune response , which is considered to be the main pathogenesis of LP , plays a critical role in causing it. The langerhans cells activated by extraneous or self-alternative antigen , have changes in shapes or numbers and secrete cell factors inducing T cells to move into inflammation area and to be activated , meanwhile the activated T cells kill and wound keratinocytes by direct or indirect ways , which can cause extensive destruction in the stratum base cell and pathological change of liquify denaturation in LP. The studies at present show that the apoptosis of keratinocyte, the change of cell differentiation mark factor and the nerve energetic factor have the close relation with the pathogenesis of LP. Now the domestic and foreign researches on the participation of virus infection in pathogenesis of LP is becoming hot spot. It is said that hepatitis C virus(HCV)has definite effect on the pathogenesis of LP, however, there is few researches on human herpesvirus7(HHV-7). The studies in abroad show that HHV-7 can duplicate in the area of LP according to a number of dendritic cells, but it is supposed that there is region difference.HHV-7 ,which belongs to a new type in the herpes virus branches,is easy to be cultivated in the umbilical cord blood and lymphocyte of the normal person circumference blood. HHV-7 mainly invade CD4+ T lymphocyte, after infecting CD4+ T lymphocyte, the activated HHV-7 would reduce the expression of its receptor CD4 factors on cell membrane, and change its numbers. The accrued characteristic of HHV-7 in CD4+ T lymphocyte explain that HHV-7 has the same receptor as HIV. So the obviously mutual interference effect between them can be used to treat AIDS , CD4+ T Lymphocyte infected by HHV-7 interfere with CD4+ T lymphocyte primarily infected by HIV by hindering the cultivation of HIV in vitro, which provided the broad prospect in practical research of HHV-7. Recently, it is proved that HHV-7 is related to the virus infection disease, but its relationship with LP was hardly studied.Objective: to establish HHV-7 the nest type polymerase chain reaction (nested-PCR) technology; to detect HHV-7 in the skin lesion of LP, and to infer its effect on pathogenesis of LP.Methods: this experiment group selects the skin lesions of 30 LP patients whose final diagnosis is through clinic and biopsy, the control group selects 30 normal skins and 10 skin lesions of the clinical manifestation doubtful LP which is not finally supported by pathological diagnosis(such as psoriasis, vascular dermatosis , syphilis , prurigo). All these groups were selected from dermatology department of second hospital in Jilin University from February, 2007 to January, 2008. This experiment adapted nested-PCR to detect HHV-7 in the above three groups. The nest-PCR products in 2% agarose gel electrophoresis, with the ultraviolet ray analyzer observation, present the special fluorescent tape in 264bp place,which is a detection mark. The HHV-7 specific primers amplify and separate virus DNA from the skin , which is considered to be HHV-7, because of the specificity and the sensitivity of the nest -PCR. The data was analyzed by using theχ~2 examination, four standard table precise probability law, the fisher accurate probability law .Results: HHV-7 is detected in the skin lesion of 30 among 34 LP patients, the detection rate is 88.2%, it is detected in 14 among 30 healthy person skin , the detection rate is 46.7%, it is also detected in 4 among 10 skin lesions of the clinical manifestation doubtful LP which is not finally supported by pathological diagnosis, the detection rate is 40%. So, the detection rate of LP patients is higher than that of healthy person skin and that of the clinical manifestation doubtful LP which is not finally supported by pathological diagnosis, there is significant difference between them(p<0.05). However, the detection rate of healthy person skin and the clinical manifestation doubtful LP which is not finally supported by pathological diagnosis has not significant difference (p>0.05).Conclusion: The skin of normal person and the skin lesion of LP patient both have the HHV-7 dormant infection, but the latter's HHV-7 detection rate is higher than the former obviously, it has significant difference. So the causing of LP is likely to be concerned with ambush's HHV-7 activation infection.It is analyzed that HHV-7 is higher in healthy crowd saliva's carrier rate, and HHV-7 has the dormant infection in the crowd. HHV-7 which ambush in saliva or (and) in uninuclear cells presents the viral duplication during being activated, and enters the skin tissue. HHV-7 multiplies in the cell may cause the cell factor network to be unbalanced, finally cause the cytopathic effect and LP pathological changes. Therefore, HHV-7 may be an important factor in the causing of LP.