Studies On Some Neuropeptides And NGF In Lichen Planus

Objectives: Lichen planus (LP) is a chronic, subacute inflammatory skin disease, occurs predominantly in adults from 30 to 60. The morbidity of this disease is lower than 1 percent in population and shows an increasing tendency at present. The etiopathogenisis and pathogenesy of LP still remains obscure which is considered to be correlated with T Lymphocytes by most people. In fact, there is no specific treatment so LP can induce some adverse influences to patient's health. We find tension, stress, depress, and some physical stimulations may lead to the recurrence and aggravation of this disease in clinic that infers to the genesis of LP is related to nerve and mind factor. Histopathologically, LP shows hyperkeratosis, focal hypergranulosis, acanthosis, typical liquefaction degeneration of basal cells and band-like inflammatory infiltrate predominantly of T cells and anapetia in the upper dermis. Substance P(SP), vasoactive intestinal peptide(VIP), somatostatin(SOM) belong to neuropeptides which are created by nerve system and some local cells such as macrophage, lymphocytes, mast cell and can regulate immune and inflammatory reactions. Its effect is chemotaxying immunocyte, regulating cytokine and relaxing micrangium. NGF is a necessary neurotrophy polypeptide for neuron survival, differentiation and exerting function. Therefore its increasement can up-regulate secretion of neuropeptide. In addition to this, it possesses other biological effects such as promoting proliferation of Malpighian cell, activation of T cell, inflammatory infiltration and angiopoiesis et al. Combining clinical and pathology characteristic of LP, it can be seen that there is maybe some kind of associativity between NGF , neuropeptides and the invasion of LP. This experiment is planned to research the expression of NGF, SP, VIP and SOM in LP lesion by immunohistochemistry method ,and investigate the relationship between them and LP, and the associativity between NGF and other three neuropeptides.Methods: Thirty-seven LP patients, diagnosed by clinic and histopathology, were collected from the dermatological department of the Fourth Affiliated Hospital of Hebei Medical University from June 2005 to June 2006. The specimens were cut to 4μm serial sections for routine HE staining, twenty-four normal skin specimens were taken as normal controls collected from trauma patients. There was no significant difference in sexes and ages between controls and patients. All data were analyzed using SPSS11.5. Mann-Whitney U test of rank sum test was used to analyze the result of immuno -histochemistry; Spearman rank correlation was used to analyze the correlation between the expression of NGF and VIP, SP, SOM. P<0.05 was considered significant.Results: 1 About thirty-five percent specimens showed underepider -mis blister of different extent. increased angiogenesis and angioectasia was found in dermis superficial lamella of about eighty-nine percent specimens. About eighty-four percent specimens showed stratum spinosum epidermis thicken irregularly. There samples showed epidermal atrophy.2 Immunohistochemistry results: NGF expressed positively in cell intracytoplasm of subepidermisl layers, and weakly positive expression was found in normal epidermis, the difference was significant(P<0.05). Positive staining of SP and VIP were seen in epidermis prickle cell layer, around some small vessels and sweat glands, also lymphocyte. The staning were weak in normal skin tissues. The difference was significant(P<0.05). Weak staining was seen in part of specimens, and there was few positive expression in normal skin. But there was no significant difference between them(P>0.05).3 Among thirteen specimens which had under-epidermis blister, the expression of indexes in nine specimens were weakly positive, even negative. The expression of them in dermis was the same as above-mentioned result.4 Statistical results of these experiment showed that there was positive associativity between NGF and VIP,SP, the values of coefficient correlation and P were respectively:NGF and VIP(epiderm)rs=0.541, P=0, NGF and VIP(vessels)rs=0.668, P=0,NGF and VIP (sweat gland)rs=0.392, P=0.001. NGF and SP(epiderm)rs=0.350, P=0.002,NGF and SP(vessels)rs=0.337, P=0.003,NGF and SP(sweat gland)rs=0.240, P=0.039.Conclusions:1 More than eighty-four percent specimens show acanthosis irregularly, liquefaction degeneration of basal cells, band-like inflammatory infiltrate predominantly of T cells and increasing angiectasis in the upper dermis.2 These results suggest all three neuropeptides may take part in the genesis and development of LP which fuctions may be chemotaxying immunocyte, regulating the generation of cytokine and relaxing micrangium.3 Over expression of NGF in LP suggests expression of neuropeptide is up-regulated through nourishing nerve, promoting the synthesis and secretion of neuropeptide.4 Positivly Significant correlation between NGF and SP,VIP suggests they cooperate to promote the lesion of LP.5 In those specimens forming blister, decreasing secretion of the four indexes may be caused by nerve fiber lesion resulting from severe inflammation. It can be supposed that the decreasing secretion of neuropeptedes induce the fuction to LP lesion weaker when the leision is very serious. We need to prove it by increasing cases.6 The expression of VIP decreases in three atrophy-type specimens, they maybe interact to promote the development of atrophy-type LP. It need more cases for further study.