1. ¹Department of Hematology, Erasmus Medical Center, Rotterdam, The Netherlands
2. ²Department of Medical Oncology, Erasmus Medical Center, Rotterdam, The Netherlands
3. ³Department of Hematology, HAGA Hospitals, The Hague, The Netherlands
4. ⁴Department of Neurology, Erasmus Medical Center, Rotterdam, The Netherlands
5. ⁵Department of Trials & Statistics, Erasmus Medical Center, Rotterdam, The Netherlands

Correspondence: Dr PAW te Boekhorst, Department of Hematology, Erasmus Medical Center Rotterdam, PO Box 2040, 3000 CA Rotterdam, The Netherlands. E-mail: p.teboekhorst@erasmusmc.nl

Received 30 August 2005; Revised 2 February 2006; Accepted 3 February 2006; Published online 6 March 2006.

Abstract

We compared the kinetics of T-cell recovery after extensive ex vivo and in vivo T-cell depleted autologous stem cell transplantation (SCT) for multiple sclerosis (MS; n=8) with unmodified SCT for hematological malignancies (HM; n=39). Both patient group showed a very protracted recovery of 'naive' CD4⁺, 45R0^- (CD45RA⁺) T-cells. Within the 'primed' CD4⁺, 45R0⁺ T-cells, the 'central memory' cells expressing the CD62L and CD27 markers were the slowest to recover. The repopulating T-cells were highly activated, as shown by increased expression of HLA-DR and the apoptosis marker CD95. The capability of CD4⁺ and CD8⁺ T-cells to produce IFN-, IL-2 and TNF- had reached normal ranges from 2 months post SCT onwards. Unexpectedly, the kinetics of T-cell recovery between 3 and 12 months post transplant was similar in T-depleted and unmodified SCT. Before SCT, the HM patients showed lymphopenia of all T-cell subsets, upregulated HLA-DR and CD95 expression and increased cytokine responses. We suggest that the similar kinetics of T-cell recovery in the two patient groups may be explained by the susceptibility to apoptosis of the activated CD4⁺ T-cells in the autografts of the HM patients. This susceptibility to apoptosis would interfere with a swift and sustained CD4⁺ T-cell regeneration post SCT.