Decreased T-Cell Repertoire Diversity in Sepsis: A Preliminary Study

1 Cellular Immunology Laboratory, Hôpital E Herriot, Lyon, France. 2 Hospices Civils de Lyon, Université Claude Bernard Lyon I, Lyon, France. 3 ImmunID Technologies, CEA/iRTSV, Grenoble, France. 4 Hospices Civils de Lyon, Intensive Care Units, Lyon-Sud University Hospital, Pierre-Bénite, Grenoble, France. 5 ImmunID Technologies, CEA/iRTSV, Grenoble, France.
Critical care medicine (Impact Factor: 6.15). 12/2012; 41(1). DOI: 10.1097/CCM.0b013e3182657948
Source: PubMed

ABSTRACT OBJECTIVE:: Septic syndromes are the leading causes of mortality in intensive care units. In patients, the occurrence of sepsis-induced immune suppression is associated with delayed mortality, although the exact role of lymphocyte dysfunctions is not well established. The objective of this study was to investigate T-cell receptor diversity, an important feature of T-cell response, in patients with septic shock. DESIGN:: Preliminary prospective observational study. SETTING:: Adult intensive care units in a university hospital. SUBJECTS:: Patients with septic shock (n = 41) sampled twice after the onset of shock (early after inclusion [day 1] and at the end of the first week [day 7]). MEASUREMENTS AND MAIN RESULTS:: Using a novel molecular biology technique, the combinatorial diversity of human T-cell receptor β-chain (TRB locus) was measured in peripheral blood. Patients with septic shock presented with a marked decreased T-cell receptor diversity after the onset of shock in comparison with normal values. Importantly, in paired samples, a very steep recovery slope of T-cell receptor diversity, never described in other clinical situations, was observed between day 1 and day 7 (p < 0.0001, Wilcoxon's paired test). Decreased T-cell receptor diversity was associated with mortality (log-rank test, p = 0.0058; hazard ratio = 4.48; 95% confidence interval 1.96-53.32), and the development of nosocomial infections (p < 0.05, Mann-Whitney U test). CONCLUSION:: Our results show for the first time that septic patients present with a marked decreased T-cell receptor diversity that returned rapidly toward normal values over time. This opens novel cognitive research perspectives that deserve to be investigated in experimental models of sepsis. After confirmation in larger cohorts of these preliminary results, T-cell receptor diversity measurements may become a crucial tool to monitor immune functions in ICU patients.

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