Ultrasensitive RNA in situ hybridization for detection of restricted clonal expression of low-abundance immunoglobulin light chain mRNA in B-cell lymphoproliferative disorders.

ABSTRACT

OBJECTIVES: To assess the feasibility of using a novel ultrasensitive bright-field in situ hybridization approach (BRISH) to evaluate κ and λ immunoglobulin messenger RNA (mRNA) expression in situ in B-cell non-Hodgkin lymphoma (NHL). METHODS: A series of 110 semiconsecutive clinical cases evaluated for lymphoma with historic flow cytometric (FCM) results were assessed with BRISH. RESULTS: BRISH light chain restriction (LCR) results were concordant with FCM in 108 (99%) of 109 evaluable cases. Additional small B-cell lymphoma cohorts were successfully evaluated. CONCLUSIONS: BRISH analysis of κ and λ immunoglobulin mRNA expression is a sensitive tool for establishing LCR in B-cell NHL when FCM results are not available.