Pre-transplant donor CD4− invariant NKT cell expansion capacity predicts the occurrence of acute graft-versus-host disease

International audienceClinically useful pre-transplant predictive factors of acute graft-versus-host-disease (aGVHD) after allogeneic hematopoietic stem cell transplantation (allo-SCT) are lacking. We prospectively analyzed HSC graft content in CD34+, NK, conventional T, regulatory T and invariant natural killer T (iNKT) cells in 117 adult patients before allo-SCT. Results were correlated with occurrence of aGVHD and relapse. In univariate analysis, iNKT cells were the only graft cell populations associated with occurrence of aGVHD. In multivariate analysis, CD4− iNKT/T cell frequency could predict grade II-IV aGVHD in bone marrow and peripheral blood stem cell (PBSC) grafts, while CD4− iNKT expansion capacity was predictive in PBSC grafts. Receiver operating characteristic analyses determined the CD4− iNKT expansion factor as the best predictive factor of aGVHD. Incidence of grade II-IV aGVHD was reduced in patients receiving a graft with an expansion factor above versus below 6.83 (9.7 vs 80%, P<0.0001), while relapse incidence at two years was similar (P=0.5).The test reached 94% sensitivity and 100% specificity in the subgroup of patients transplanted with human leukocyte antigen 10/10 PBSCs without active disease. Analysis of this CD4− iNKT expansion capacity test may represent the first diagnostic tool allowing selection of the best donor to avoid severe aGVHD with preserved graft-versus-leukemia effect after peripheral blood allo-SCT

Plasma exchange in the intensive care unit: a narrative review

In this narrative review, we discuss the relevant issues of therapeutic plasma exchange (TPE) in critically ill patients. For many conditions, the optimal indication, device type, frequency, duration, type of replacement fluid and criteria for stopping TPE are uncertain. TPE is a potentially lifesaving but also invasive procedure with risk of adverse events and complications and requires close monitoring by experienced teams. In the intensive care unit (ICU), the indications for TPE can be divided into (1) absolute, well-established, and evidence-based, for which TPE is recognized as first-line therapy, (2) relative, for which TPE is a recognized second-line treatment (alone or combined) and (3) rescue therapy, where TPE is used with a limited or theoretical evidence base. New indications are emerging and ongoing knowledge gaps, notably regarding the use of TPE during critical illness, support the establishment of a TPE registry dedicated to intensive care medicine