Study On The Gene Rearrangement In Primary Cutaneous T-cell Lymphoma Of Early Stage

IntroductionPrimary cutaneous T - cell lymphoma ( CTCL) , which mainly includes mycosis fungoides ( MF) and Sezary syndrome (SS) , is a low malignant cutaneous lymphoma. MF has a variety of manifestation in the early stage and is difficult for early diagnosis in pathology. Very often, the ultimate diagnoses are based on repeated biopsy and further development of the lesion. In MF, the monoclonal o-rigination of malignant tumor is embodied in the clonal rearrangement of T cell recptor ( TCR). Theoretically, if only we can exactly detect the clonal rearrangement of TCR, MF is exactly diagnosed. For this reason, since the 1980's several methods have been proposed in the world, however, none of them is widely applied for clinical diagnosis. We analyzed the methods'advantages and disadvantages to select a simple and rapid new detection for the TCR clonal rearrangement; " one - step" method to extract DNA from paraffin - embeded tissue , nested - PCR to detect the colonal rearrangement of TCR - V_r, sepharose electrophoresis to show the result. Our clinical case - control study showed that our method has high specificity and sensitivity, thus is fit to be an assistant measure for the diagnosis of MF. With this method, we detected the clonal rearrangement of TCR - V_r in parapsoriasis, the high positive rate suggests the internal relationship to MF. The purpose of our research is to discuss the significance of TCR clonal rearrangement detection in diagnosis of MF.Materials and MethodsMaterials; 10% formalin fixed, paraffin -embedded tissue samples, including ; MF 59 cases, neurodermatitis 20 cases, chronic eczema 20 cases, parap-soriasis 40 cases, all taken from laboratory of dermatopathology in No. 1 Hospital of China Medical University. Normal skin sample 20 cases taken from department of cosmetic surgery, No. 1 Hospital of China Medical University.Methods; 1. cut paraffin - embedded tissue sections, routine deparaffimza-tion, digest with protease K (working concentration 200μg/ml) for 17 hours, 95℃ heat for 10 minutes to inactivate protease K, centrifuge and take the supernatant as template. 2. run nested PCR to detect clonal rearrangement of TCR V_r 1 -8/J_r and V_r9/J_r. 3. 1% sepharose electrophoresis to show the result, record with UV gel - imaging system.Results1. MF; For 59 MF cases 49 were detected positive, the positive rate was 83%.2. Eczema, neurodermatitis: each 20 cases, no positive detected.3. Normal skin; 20 cases, no positive detected.4. The case - control study based on clearly diagnosed MF and eczema, neurodermatitis, normal skin shows; our method has the sensitivity of 83% , the specificity of 100%.5. Parapsoriasis; 40 cases, 24 cases showed positive, positive rate was 60% , lower than MF, the difference is statistically significant.ConclusionsOur method to detect the clonal rearrangement of TCR - V_r is easy and quick, at the same time has a relatively high specificity and sensitivity, thus is fit to serve as an assistant test for diagnosis of MF.