A parallel comparison of T-cell clonality assessment between an in-house PCR assay and the BIOMED-2 assay leading to an efficient and cost-effective strategy.

AIMS: Diagnosis of T-cell lymphoproliferation is sometimes challenging, and in certain instances pathologists rely heavily on the clonality assessment results of T-cell receptor (TCR) gene rearrangement (TCR-GR). Many investigators have designed various in-house primer sets for PCR-based study targeting different loci of TCR genes. In recent years, the commercial BIOMED-2 protocols have become available. The in-house primers are very cheap while the BIOMED-2 primers are expensive. This parallel study aimed to compare the sensitivity of the in-house TCRG primers (two reactions) and the BIOMED-2 TCR primers (six reactions) in an attempt to develop a sensitive and cost-effective strategy for TCR-GR assessment.

METHODS

PCR-based analysis was performed on 69 samples of T-lineage neoplasms including 60 formalin-fixed paraffin-embedded (FFPE) tissues, 5 samples from peripheral blood (PB) and 4 samples from bone marrow (BM) aspirate.

RESULTS

Forty-seven (78%) FFPE and all PB or BM aspirate samples yielded control DNA products suitable for clonality assessment including 4 precursor and 50 mature T-cell neoplasms. The detection rates of clonal TCR-GR were 63% (34/54) by the two in-house TCRG primers, 85% (46/54) by all six BIOMED-2 reactions, 91% (49/54) by combining the in-house and BIOMED-2 TCRG reactions and 94% (51/54) by combining the in-house and all BIOMED-2 reactions. By using the in-house and BIOMED-2 TCRG reactions with a total of four tubes, clonal TCR-GR was detected in 91% of the cases. The reagent cost for this combination was one-third of that for the six BIOMED-2 reactions and the detection rate was also higher than the latter alone (91% vs 85%).

CONCLUSIONS

As the in-house primers were custom made and are much cheaper than the commercial kits, the authors concluded that this four-tube strategy was cost-effective and efficient for TCR-GR clonality assessment.