[Study of B-lymphocyte clonality using in vitro gene amplification (PCR) in paraffin embedded samples]

Family-specific primers were used in polymerase chain reaction (PCR) to analyse clonality of immunoglobulin heavy chain (IgH) gene rearrangement. DNA templates were extracted from formalin-fixed paraffin-embedded biopsies from B-cell lymphomas (n = 19), T-cell lymphomas (n = 3), reactive lymphadenopathies (n = 20) and negative controls (n = 2). PCR was also performed on DNA extracted from fragments of the same biopsies that were either fixed in Bouin's solution (n = 24) or snap-frozen (n = 22). The latter were also studied for IgH gene rearrangement by the Southern blot technique. Polyclonal or clonal fragments were obtained from all frozen biopsies. No amplification was observed in 3 out of 44 formalin fixed specimens and 18 out of 24 Bouin fixed specimens. A clonal amplification was only observed in 16 out of 19 formalin-fixed B-cell lymphoma specimens. Therefore this technique allows to study B-cell clonality from formalin-fixed, embedded material.