ASSESSMENT OF CMV SPECIFIC IMMUNITY BY FLOW CYTOMETRY USING A COMBINED APPROACH OF SPECIFIC CMV CELL ENUMERATION AND FUNCTIONAL T CELL ANALYSIS

Konference: 2013 18th Congress of the European Hematology Association - účast ČR

Kategorie: Maligní lymfomy a leukémie

Téma: Stem cell transplantation - Experimental

Číslo abstraktu: P885

Autoři: Mgr. Vlasta Tkáčová; MUDr. Michal Kouba; MUDr. Veronika Válková, CSc.; doc. MUDr. Milada Kohoutová, CSc.; Adam Pešek; doc. MUDr. Petr Cetkovský, Ph.D.; MUDr. Iuri Marinov, CSc.

Background:

CMV reactivation is one of the most frequent infectious complications following allogeneic stem cell transplantation (SCT). CMV specific memory CD8+ cells (CMV CD8+ Tly) play crucial role in the regulation of CMV infection. In practice, CMV specific response can be monitored by detection and quantification of CMV CD8+ Tly using tetramer technology and/or ex-vivo assessment of CMV induced T cell function.

Aims:

To study the recovery of CMV specific immunity by analysing the functional activity of CMV stimulated CD8+ Tly in terms of simultaneous production of IL-2 and IFNg in correlation with CMV CD8+ Tly enumeration by CMV tetramer test.

Methods:

In 37 patients after SCT, we determined the presence of CMV CD8+ Tly using the CMV tetramer test and simultaneously evaluated the functional status of CMV stimulated CD8+ Tly by evaluation of intracytoplasmic presence of both IL-2 and IFN-g using multiparameter flow cytometry (MPFCM).

Results:

During the last 4 months, 37 patients were analyzed on day +60, +150, +240, +360 following SCT. In 10 (27%) patients, we demonstrated the presence of CD8+IL-2+INFg+ double positive cells, indicating sufficient CMV specific response of Tly in agreement with literary data. In 7 of 10 cases (70%), we proved the presence of CMV CD8+Tly: 203 c/µl (min. 51 c/µl, max. 785 c/µl).  All of these 10 patients didn’t experience any CMV complications. In 3 of 37 patients (8%) suffered from severe CMV infection and neither CMV CD8+ Tly, nor CMV CD8+IL-2+,IFNg+ Tly were identified.

Summary / Conclusion:

Preliminary results suggest possible correlation between ex-vivo functional activities of CMV stimulated Tly and the presence of tetramer positive CMV CD8+Tly in concentration > 10 c/µl. Further analysis is necessary to confirm this observation and implement both techniques in clinical practice for laboratory evaluation of CMV specific immunity recovery and optimal timing of anti-CMV therapy.

Keywords: CMV, Flow cytometry

Abstrakta v časopise Haematologica 2013, Suppl1

Online Program 

Datum přednesení příspěvku: 15. 6. 2013