Determination of thymic function directly from peripheral blood: A validated modification to an established method☆


The thymus contributes naïve, self MHC reactive, self tolerant T cells to the peripheral immune system throughout life, albeit with a log-linear decline with age. Quantification of thymic function is clinically relevant in the setting of lymphoablation, but a phenotypic marker distinguishing recent thymic emigrants from long lived naïve T cells remains elusive. T cell receptor excision circles (TREC) are present in thymocytes exiting the thymus and quantification of the most frequent of these, the deltarec-psiJalpha rearrangement has been widely used as a measure of recent thymic function. However, interpretation of results presented as TREC per cell has been criticised on the basis that extra-thymic cellular proliferation impacts on peripherally determined TREC numbers. TREC/ml is now considered to be more representative of thymic function than TREC/cell, especially where significant cellular proliferation occurs (e.g. during reconstitution following stem cell transplantation). Here we describe the validation of a novel variation to the established assay, directly quantifying TREC/ml from 300 microl whole blood. We show the assay to be reproducible, robust and stable longitudinally and we show equivalence of performance when compared with more standard assays. This assay particularly lends itself to the measurement of thymic function in children and where monitoring clinical variables is limited by tissue availability.

DOI: 10.1016/j.jim.2008.09.013
Citations per Year

295 Citations

Semantic Scholar estimates that this publication has 295 citations based on the available data.

See our FAQ for additional information.

Cite this paper

@inproceedings{Lorenzi2008DeterminationOT, title={Determination of thymic function directly from peripheral blood: A validated modification to an established method☆}, author={A. R. Lorenzi and A. M. Patterson and A. V. Pratt and Mia Jefferson and C. E. Chapman and Fr{\'e}d{\'e}rique Ponchel and John Isaacs}, booktitle={Journal of immunological methods}, year={2008} }