Molecular tests for clonality performed on atypical lymphoid lesions may yield abnormal results because of the coexistence of monoclonal B lymphocytosis or monoclonal gammopathy of undetermined significance in the sample investigated.
To investigate the ability of the BIOMED-2 sets of primers to identify 2 clonal populations in the same formalin-fixed, paraffin-embedded tissue sample. Design.-Ten cases with 2 B-lymphoproliferative disorders at the same site were analyzed using 5 BIOMED-2 primer sets (IGH FR1, FR2, FR3, IGK VJ, and IGK VKde).
All 10 cases (100%) showed at least 1 clone; 8 of 10 cases (80%) had 2 clones with at least 1 primer set, and the 2 clones were shown by 4 or 5 primer sets in none of the cases (0%), by 3 sets in 1 of 10 cases (10%), by 2 sets in 4 of 10 cases (40%), and by 1 set in 3 of 10 cases (30%). The most effective set was IGH FR2, detecting 4 of 10 biclonal cases (40%). The IGK VJ and IGK VKde each showed 2 clones in 3 of 10 cases (30% each). The least effective sets were IGH FR1 and FR3, with 2 of 10 cases (20%) each, with IGH FR1 being the least useful.
The BIOMED-2 primers are effective in the detection of 2 clonal populations in the same sample.