Immunoglobulin heavy and light chains and T-cell receptor beta and gamma chains PCR assessment on cytological samples. A study comparing FTA cards and cryopreserved lymph node fine-needle cytology.

Objectives To evaluate and compare the DNA yield and quality extracted from lymph node fine needle cytology ( FNC) samples stored on FTA cards to those cryopreserved, and to assess the immunoglobulin heavy and light chains ( IGHK) and T-Cell receptor beta and gamma chains ( TCRBG) PCR tests. Methods DNA extractions were performed on FNC of 80 non-Hodgkin lymphomas ( NHL), four myelomas and 56 benign reactive hyperplasias ( BRH) cryopreserved and stored on FTA cards. The JAK2 gene was amplified to assess the DNA integrity and the IGHK/ TCRBG clonality status was tested. Results IGHK monoclonality was found in 99% of B-cell NHL and 100% of myeloma. TCRBG monoclonality was found in 100% of T-cell NHL. TCRBG polyclonality was detected in 97% of B-cell NHL, 100% of myeloma and 96% of BRH. IGHK/ TCRBG PCR data were confirmed by histological and/or follow-up controls. No differences were found in the DNA quality between cryopreservation and FTA cards storage methods. Conclusions IGHK/ TCRBG PCR of the lymphoproliferative process on FTA cards is comparable to those cryopreserved. FTA cards can be used to store lymph node FNC for further molecular investigations. [ABSTRACT FROM AUTHOR]