Molecular detection of clonality in B cell lymphoma / Samah Mohammed Fadl Ibrahim ; Supervised Mona Salah Eldein Hamdy , Thoraia Mohammed Abdelhameed , Amira Hanafy Soliman

Thesis (M.Sc.) - Cairo University - Faculty of Medicine - Department of Clinical and Chemical Pathology

The vast majority of B lymphoid malignancies contain identical (i.e. clonal) rearrangements of the immunoglobulin (IG), which can serve as a clonality marker. This study aimed to evaluate the added value of standardized molecular assay of B-cell clonality in the diagnostic setting of suspected B-cell lymphoma. The results of molecular assay of clonality were compared to routine histopathological examination and IHC results regarding the sensitivity and feasibility in differentiating malignant and reactive lymphoid proliferation. This study included 30 archived bone marrow biopsy samples collected from 30 patients referred to clinical pathology department, Faculty of medicine, Cairo university. Clonality testing was done using IGH tubes A, B, and C target the framework 1, 2, and 3 regions (respectively) within the variable region, and the joining region of the IGH locus in all cases. IGK Tubes A and B target the variable, intragenic and joining regions of the IGK locus was used in some cases.Results showed agreement between clonality testing and immunomorphological results in all cases of the lymphoma group (11 cases) and in 6/11 cases of the reactive group. Molecular clonality confirms the suspicious diagnosis in all the cases of minimal lymphoma infiltrates (8 cases). Discordant results between clonality testing and immunmorphology were found in five cases of the reactive group which warrant close follow up of those patients. 80% of the studied cases showed 100% consistent results when analyzed by both agarose gel and QIAxcel capillary electrophoresis.In conclusion, BIOMED-2 multiplex PCR assay was a useful adjunctive method for diagnosing B lymphoproliferative disorders

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