Badanie chimeryzmu specyficznego liniowo po allogenicznym przeszczepieniu komórek macierzystych

IntroductionDonor lineage-specific chimerism of hematopoietic cells enables very precise monitoring of engraftment in selected cell lines after allogeneic stem cell transplantation (allo-SCT).Materials and methodsThe study group consisted of 12 acute leukemia patients who underwent allo-SCT in the Department of Hematology and Bone Marrow Transplantation in Katowice, Poland. Lineage-specific chimerism was assessed in B cells (CD19+ CD38−/+), plasma cells (CD19+ CD38++), T cells (CD3+ or CD7+ CD56−), monocytes (CD14+), and immature progenitor cells deriving from myeloid line (CD34+CD19). We also assessed erythrocyte chimerism by flow cytometry.ResultsAll patients engrafted. 8 out of 10 patients presented normal donor hematopoiesis. Lineage specific chimerism in these patients corresponded with chimerism analysis in unsorted material and with undetectable minimal residual disease (MRD). Relapse of the underlying disease was diagnosed in 2 patients. In both cases loss of donor chimerism occurred in leukemia specific cell line and corresponded with detectable MRD. One patient with secondary graft failure presented decreasing lineage specific chimerism in all subpopulations, with negative MRD status. In 10 patients normal hematopoiesis of donor-origin was assessed by flow cytometry. In one case no donor-derived erythrocytes were detected and the diagnosis of pure red cell aplasia was set.ConclusionsLineage specific chimerism as a method of high sensitivity and specificity allows for precise assessment of donor chimerism especially in clinically ambiguous situations. Assessment of erythrocyte chimerism by flow cytometry is a reliable method of monitoring erythroblastic line engraftment. Presented results are preliminary and the study is being continued

Analysis and influence of anti-HLA antibodies after allogeneic hematopoietic stem cell transplantation from HLA-mismatched unrelated donors

Przeciwciała skierowane przeciw głównemu układowi zgodności tkankowej są istotnym czynnikiem odpowiedzialnym za odrzucenie przeszczepu w przypadku transplantacji narządów litych. Ich wpływ na wyniki allogenicznego przeszczepienia komórek krwiotwórczych, szczególnie od dawcy niezgodnego w układzie HLA, nie został dotychczas poznany. Wobec wzrastającej liczby allotransplantacji komórek krwiotwórczych od dawców niespokrewnionych nie w pełni zgodnych w układzie HLA, zaistniała potrzeba zbadania występowania oraz wpływu przeciwciał anty-HLA na wyniki procedury przeszczepowej. Celem naszej pracy było zbadanie występowania, swoistości oraz wpływu przeciwciał anty-HLA na wyniki przeszczepienia macierzystych komórek krwiotwórczych od dawców niespokrewnionych nie w pełni zgodnych w układzie HLA z biorcą przeszczepu. Do badania włączono 30 pacjentów poddanych transplantacji komórek krwiotwórczych w Klinice Hematologii i Transplantacji Szpiku SUM w Katowicach w latach 2001–2007. Przeciwciała anty-HLA były wykrywane przy użyciu techniki DynaChip w surowicach pobranych od chorych w różnym czasie od przeprowadzonej procedury przeszczepowej. Technika DynaChip łączy w sobie zmodyfikowaną metodę ELISA z techniką microchipów wykorzystującą rozpuszczalne, oczyszczone glikoproteiny HLA zarówno klasy I, jak i II, opłaszczone na powierzchni studzienek. Wstępne obserwacje wskazują, że po allotransplantacji są wytwarzane przeciwciała skierowane przeciw głównemu układowi zgodności tkankowej i mogą one mieć potencjalny wpływ na wyniki procedury transplantacyjnej.Antibodies against human leukocyte antigen (anti-HLA Abs) are important factors responsible for graft rejection in solid organ transplantation, but their role in allogeneic hematopoietic stem cell transplantation (allo-HSCT) is unknown. As the number of patients who are treated with HLA-mismatched HSCT (including cord blood, haploidentical and unrelated HSCTs) constantly increases, the presence and influence of anti-HLA antibodies on the HSCT outcome is unknown. Thus we have examined incidence and influence of anti-HLA antibodies on outcomes of allo-HSCT from HLAmismatched unrelated donors. Abs were identified in sera collected from 30 recipients. We have used automated DynaChip assay which uses microchips bearing purified class I and II HLA antigens for detection of anti-HLA Abs. The preliminary results indicate that anti-HLA Abs appear post transplant in mismatched allo-HSCT recipients and may be potentially responsible for the occurrence of post-transplant complications

Role of Donor Activating KIR–HLA Ligand–Mediated NK Cell Education Status in Control of Malignancy in Hematopoietic Cell Transplant Recipients

AbstractSome cancers treated with allogeneic hematopoietic stem cell transplantation (HSCT) are sensitive to natural killer cell (NK) reactivity. NK function depends on activating and inhibitory receptors and is modified by NK education/licensing effect and mediated by coexpression of inhibitory killer-cell immunoglobulin-like receptor (KIR) and its corresponding HLA I ligand. We assessed activating KIR (aKIR)-based HLA I–dependent education capacity in donor NKs in 285 patients with hematological malignancies after HSCT from unrelated donors. We found significantly adverse progression-free survival (PFS) and time to progression (TTP) in patients who received transplant from donors with NKs educated by C1:KIR2DS2/3, C2:KIR2DS1, or Bw4:KIR3DS1 pairs (for PFS: hazard ratio [HR], 1.70; P = .0020, Pcorr = .0039; HR, 1.54; P = .020, Pcorr = .039; HR, 1.51; P = .020, Pcorr = .040; and for TTP: HR, 1.82; P = .049, Pcorr = .096; HR, 1.72; P = .096, Pcorr = .18; and HR, 1.65; P = .11, Pcorr = .20, respectively). Reduced PFS and TTP were significantly dependent on the number of aKIR-based education systems in donors (HR, 1.36; P = .00031, Pcorr = .00062; and HR, 1.43; P = .019, Pcorr = .038). Furthermore, the PFS and TTP were strongly adverse in patients with missing HLA ligand cognate with educating aKIR-HLA pair in donor (HR, 3.25; P = .00022, Pcorr = .00045; and HR, 3.82; P = .027, Pcorr = .054). Together, these data suggest important qualitative and quantitative role of donor NK education via aKIR-cognate HLA ligand pairs in the outcome of HSCT. Avoiding the selection of transplant donors with high numbers of aKIR-HLA-based education systems, especially for recipients with missing cognate ligand, is advisable

Interferon-γ and interleukin-2 in patients with acute graft-versus-host disease and infectious complications after allogeneic hematopoietic stem cell transplantation

IntroductionThe allogeneic Hematopoietic Stem Cells Transplantation (alloHSCT) is associated with the risk of Graft versus Host Disease (GvHD) and infections. The pathogenesis of acute GvHD is related to T-lymphocytes, which identify alloantigens on host's Antigen Presenting Cells, induce production of IFN-γ and IL-2, recruit the immunological effectory cells and destroy tissues and organs.AimThe aim of the study was to analyse the relationship between IL-2 and IFN-γ serum concentrations and acute GvHD and infections.Material and methodsThe study involved 62 patients, 30 (48%) male and 32 (52%) female, aged at median 49.5 (19–68) years, after alloHSCT from sibling (n=12) or from unrelated donor (n=50) performed for acute myeloid leukemia (AML) with myeloablative conditioning (n=26, 42%) and with non-myeloablative conditioning (n=36, 58%) in Katowice in years 2012–2014. All patients received standard immunosuppressive therapy with cyclosporin-A and methotrexate plus pre-transplant anti-thymocyte globulin in unrelated setting. Blood samples were collected pre-transplant before start and after (on day -1) the conditioning therapy and on days +2 +4, +6, +10, +20, +30 after alloHSCT. The IL-2 and IFN-γ serum concentrations were determined with use of ELISA assay. Before statistical analysis patients were divided into 4 groups according to the presence of acute GvHD and clinical manifestation of bacterial, viral or fungal infection.ResultsGroup I – patients with neither acute GvHD nor infectious complications, n=15 (24%), group II – patients with infectious complications without acute GvHD, n=17 (27%), group III – patients with acute GvHD without infectious complications, n=9 (15%), and group IV – patients with both acute GvHD and infectious complications, n=21 (34%). IFN-γ levels were higher in group II than in other groups on days +20 (p=0.014) and +30 (p=0.008). The POST-HOC tests revealed lower levels of IFN-γ on day +30 in group I (p=0.039) and in group IV (p=0.017) as compared to group II. The concentration of IL-2 was undetectable in almost all patients at all studied time points.ConclusionSerum concentration of IFN-γ following alloHSCT gradually increases. High serum concentration of IFN-γ is related to infectious complications rather than to acute GvHD. Undetectable serum concentration of IL-2 in majority of patients prevents from drawing conclusions