Study On IgH Gene Rearrangement In Ocular Adnexal Lymphoma

Objective:Ocular adnexal lymphoma is a kind of commonly seen malignant ocular adnexal tumor.The extranodal marginal-zone B-cell lymphoma is the most common subtype of it.It is a kind of small cell lymphoma.It is hard to differentiate ocular adnexal lymphoma and reactive lymphoid hyperplasia in ocular adnexal morphologically and will sequently affect the treatment and evaluation of the prognosis.These years,following the development of Immunohistochemistry and molecular biological technique,the differentiated diagnosis were seemingly increased. In our study,we use PCR technique to test the IgH gene rearrangement of the FRⅡand FRⅢregion.We examined the amplified products on high resolution agarose gel electrophoresis.We tried to find out whether IgH PCR study is helpful for the diagnosis of Ocular adnexal lymphoma.Methods:We collected 50 paraffin embedded Ocular adnexal lymphoma specimens and 15 lymphoid hyperplasia specimens in ocular adnexal which excluded infectional diseases(like bacterial,fungal,tuberculous infection),Wegener granuloma and TAO.All the specimens were preserved in the pathological department of our hospital dating from Janauary,2002 to March,2009.All specimens' sections were stained by hemotoxylin and eosin,and immunohistochemical dyeing with CD20, CD3,CD45Ro.New pathological diagnosis and classification were made according to the WHO 2001 lymphoma classification standards.PCR testing of the IgH gene rearrangement aimed at the conservative region FRⅡand FRⅢ,used the primer pair of FR2A,FR3A.DNA mini kit methods were used to extract DNA from Paraffin-Embedded Samples According to the manufacturer's instructions.The DNA quality was confirmed by PCR amplification of housekeeping geneβ-actin.Unqulified specimens were excluded from the study.Seminest PCR technique were used.Amplified products were visualized under UV illumination after electrophoresis on high resolution Agarose gel.A molecular weight marker was included in each run.Consequence criterion:Positive:Amplified products on Agarose gel electrophoresis has one or two straps in the expected area.Negative:Amplified products on Agarose gel electrophoresis has no special straps in the expected area or has a smear strap.Results:There are 50 ocular adnexal lymphoma specimens.All of them are B cell non Hodgkin lymphoma,36 are extranodal marginal-zone B-cell lymphoma, mucosa-associated lymphoid tissue type(MZL-MALT),2 are follicular lymphoma, 1 is plasmocytoma,3 are diffuse large B cell lymphoma,8 are lymphoplasmatic lymphoma.7 of 50 lymphoma specimens and 3 of 15 lymphoid hyperplasia specimens were excluded byβ-actin PCR amplification.4 lymphoma specimens were excluded due to too small specimens for DNA extraction.For lymphoma specimens,the positive rate of IgH gene rearrangement of FR2 primer pair was 79.49%,The positive rate of IgH gene rearrangement of FR3 primer pair was 61.54%,the combined positive rate of IgH gene rearrangement of FR2 and FR3 primer pair was 92.31%.For lymphoid hyperplasia specimens,the positive rate of IgH gene rearrangement of FR2 primer pair was 33.33%,The positive rate of IgH gene rearrangement of FR3 primer pair was 0.00%,the combined positive rate of IgH gene rearrangement of FR2 and FR3 primer pair was 33.33%.Lymphoma and lymphoid hyperplasia specimens have significant difference in positive rate of IgH gene rearrangement.(SPSS 13.0 )Conclusion;Combination of FR2 and FR3 IgH gene rearrangement is an obje ctive method for B cell ocular adnexal lymphoma which has a high positive r ate.It is a effective auxiliary diagnosis for ocular adnexal lymphoma.Howeve r,it must be combined with pathomorphological and immunohistochemistrical t echnique.Gene rearrangement can't take the place of pathomorphological and i mmunohistochemistrial test.It can only be used as a additional diagnostic met hod.