The Expression And Significance Of Cytotoxic Proteins In Stevens-Johnson Syndrome And Toxic Epidermal Necrolysis

Introduction:Stevens-Johnson Syndrome and toxic epidermal necrolysis are drug-induced diseaseswhich expressed mainly as exfoliation and necrosis of the epidermis, mucosalinvolvement. Its states change quickly, and the skin lesions always diffuse in the wholebody, followed by fever and the damages in the Liver and kidney function.Themortality is quite high(>30%).The pathogenesis of SJS and TEN is not absolutely clear. SJS and TEN are belong tothe type Ⅳc of allergy reaction by recently research. The feature of this type of reaction isthe activation of the cytotoxic T cells which can secrete cytotoxic proteins to induce theapoptosis of the target cells.The cytotoxic proteins are secreted by NK,NKT and CD8postive T cells,and someresearch confirmed that some cytotoxic proteins such as Granzyme-B，Granulysin andPerforin can induce the apoptosis and necrosis of the target cells. FasL is When the cytotoxic T cells recognize the target cells, the FasL in the CTL cell surface can cantactwith the Fas in the target cell, and then activate the intracellular apoptosis and make thetarget cell dead. Perforin can pass the poly perforin tubular channels in the poly target cellmembrane to make the target cell dissolve, at the same time, some other cytotoxicproteins such as Granulysin and Granzyme-B can entry into theses channels and then playa role in the intracellur infection.Granulysin is a kind of cytotoxic proteins in an hot issue in recent years. In theprocess of immune reaction in organism,3to5days after the proliferatin and activation ofCTL cells, Granulysin, Perforin and Granzyme-B are secreted and take part in the processof anti-infection, anti-viral and antineoplastic. Though many scholars considered thePerfoin and sFasl as the mainly effect molecules in the apoptosis of the epidermis cell,however， the concentration of these molecules is so lower in the blister of theStevens-Johnson and toxic epidermal necrolysis patients that people can not understandhow these moleculers in such a low concentration can induce the apoptosis and necrolysisof the epidermis cell. In addition,sFasl need the contact of CTL and the target cell to playits role,but the mounts of sFasl infiltrate in the epidermal is quite a little.Some Taiwanresearcher found that the levels of Granulysin was quite higher in the blister ofStevens-Johnson and toxic epidermal necrolysis patients than any other blister diseases.They also used immunohistochemical staining to find out that Granulysin largely depositin the epidermis in Stevens-Johnson and toxic epidermal necrolysis patients, inaddition,after injecting Granulysin into the skin of the mouse,they discovered the comingof the bliser in the mouse epidermis.It was known that cytotoxic proteins play important role in the epidermal necrolysisof TEN, so they might be correlated with the clinical feature.In addition, in the early stateof TEN,it always display as erythema and papules, it was difficult to distinguish TEN andordinary types of drug-induced skin reactions. Is it possible that the cytotoxic proteins act as amarker to distinguish them?Therefore, we select the cytotoxic proteins as the study object, by observing thecytotoxic protein levels and the source in Stevens-Johnson and toxic epidermal necrolysis patient to offer biasis for the early diagnosis and differential diagnosis, then we analyzeclinical indicator with the cytotoxic levels to provide the measurement for the therapy andprognosis evaluation.ObjectiveBy detecting the cytotoxic protein levels in the serum and peripheral bloodmononuclear cell,and then discuss the role of cytotoxic proteins in the necrosis ofStevens-Johnson and toxic epidermal necrolysis patients and offer experimental biasis tothe early diagnosis and differential diagnosis.MethodThe study including7TEN patients and8SJS patients,7females and8males.All ofthem are patients in department of dermatology, Xijing hospital. The ages were between14to51years old, and the average age were28years old.The course of the patients werelast from0to9days. The culprit drugs were antibiotic，anti-epileptic and NSAIDs. TheODSRs patients were consist of7EM and8MPE patients, and the culprit drug includepenicillin, acetaminophen, diclofenac sodium and so on. We also took10healthyvolunteers come from the medical center as the control, whose gender and ages have nosignificiance with the subjects.We used ELISA and FACS to detect the the cytotoxic protein levels in the serums andPBMCs, and each experiment we take the ordinary types of drug-induced skin reactionspatients and the Healthy as control. We also analyze the correlation between the cytotoxicproteins and the clinical significance. In addition, we used FACS to select the CD8postive memory T cell and then incubate them with the EB-transformed B cell andcausal drugs, and then CCK8was used to detect the proliferation in each group of T cells.ResultsThe levels of Granulysin in Stevens-Johnson and toxic epidermal necrolysis patients(0.269±0.138ng/ml) were higher than erythema multiforme patients（0.05+0.006ng/ml）,maculopapule eruption patients(0.02+0.003ng/m）and healthy contro（l0.01+0.005ng/ml），（P<0.05）. Granulysin was selectively expressed in the CD8postive T cells.After therapythe levels of Granulysin went down. The levels of Perforin in Stevens-Johnson and toxic epidermal necrolysis patients were higher than EM patients, but with on significance withthe MPE patients. Granzyme-B is lower in CD8positive T cells in SJS-TEN patients butnot in the serums. The levels of sFasl in the serums of SJS-TEN patients is higher thanother control. The levels of Granulysin in PBMC and serums were respectively positivecorrelated with the CK-MB and CK,but not the same condition in the A/G,AST and ALTof the patients.By FACS we find that the cell secrete cytotoxic proteins are CD8positive T cells, andin vivo experiment,we discover that the effector memory T cells proliferate the mostrapidly.ConclusionThe levels of cytotoxic proteins in Stevens-Johnson Syndrome and toxic epidermalnecrolysis may be associate with the severity of the diseases, in addition, the level ofGranulysin was specially expressed in SJS-TEN patients so it could be considered as themolecule marker to distinguish SJS-TEN patients and ordinary types of drug-induced skinreactions. Besides, it may also correlated with myocardial injury.The CD8positive T cellsthat produced cytotoxic proteins were effector T cells and effector memory T cells.These two groups of cells proliferate fast especillay the effector memory T cells, so theymay play important role in the pathogenesis of Stevens-Johnson Syndrome and toxicepidermal necrolysis.