Shared epitope and polymorphism of MICA and NKG2D encoding genes in Greek and Polish patients with rheumatoid arthritis.

The present study aimed to analyse and compare the distribution of MICA (rs1051792) and NKG2D/KLRK1 (rs1154831, rs1049174, rs2255336) polymorphisms in 61 Greek and 100 Polish patients with rheumatoid arthritis in relation to the presence of the HLA-DRB1 shared epitope and clinical parameters. Genotyping of selected polymorphism was performed using real-time PCR. HLA-DRB1 shared epitope alleles segregated differently in Greek and Polish patients but in both populations were detected in over 60% of cases. The rs1051792-A variant was more common among SE-positive Polish patients (p = 0.003) while the rs1049174-G allele was more frequently observed in Greeks than in Poles (p < 0.001). Moreover, among Greek patients, the rs1051792-GG homozygotes more frequently presented with anti-CCP antibodies and rheumatoid factor (RF), while carriers of the rs1049174-G variant and rs1154831-CC homozygotes were characterized by lower disease activity scores (p < 0.05 in all cases). These results imply that, in addition to the HLA-DRB1 SE alleles, MICA and NKG2D polymorphisms may also play a role in rheumatoid arthritis.

HLA-inferred extended haplotype disparity level is more relevant than the level of HLA mismatch alone for the patients survival and GvHD in T cell-replate hematopoietic stem cell transplantation from unrelated donor.

Serious risks in unrelated hematopoietic stem cell transplantation (HSCT) including graft versus host disease (GvHD) and mortality are associated with HLA disparity between donor and recipient. The increased risks might be dependent on disparity in not-routinely-tested multiple polymorphisms in genetically dense MHC region, being organized in combinations of two extended MHC haplotypes (Ehp). We assessed the clinical role of donor-recipient Ehp disparity levels in N = 889 patients by the population-based detection of HLA allele phase mismatch. We found increased GvHD incidences and mortality rates with increasing Ehp mismatch level even with the same HLA mismatch level. In multivariate analysis HLA mismatch levels were excluded from models and Ehp disparity level remained independent prognostic factor for high grade acute GvHD (p = 0.000037, HR = 10.68, 95%CI 5.50-32.5) and extended chronic GvHD (p < 0.000001, HR = 15.51, CI95% 5.36-44.8). In group with single HLA mismatch, patients with double Ehp disparity had worse 5-year overall survival (45% vs. 56%, p = 0.00065, HR = 4.05, CI95% 1.69-9.71) and non-relapse mortality (40% vs. 31%, p = 0.00037, HR = 5.63, CI95% 2.04-15.5) than patients with single Ehp disparity. We conclude that Ehp-linked factors contribute to the high morbidity and mortality in recipients given HLA-mismatched unrelated transplant and Ehp matching should be considered in clinical HSCT.

Prediction of NK Cell Licensing Level in Selection of Hematopoietic Stem Cell Donor, Initial Results.

Natural killer (NK) cell licensing status depends on clonal expression of inhibitory killer cell immunoglobulin-like receptors (iKIR) and short term HLA environment. Licensed NK cells are more efficient in tumor killing than unlicensed NK cells. Cognate KIR-HLA pairs in hematopoietic stem cell transplant (HSCT) donor and recipient are decisive for the possible change in the NK cell licensing status after HSCT. We assessed clinical outcomes in 297 patients with lymphoproliferative or myeloproliferative malignancies, or myelodysplastic syndrome in a model with upward licensing, downward resetting, and unchanged licensing genetics status after T cell replate HSCT from unrelated donors. We found extremely low (0%) relapse/progression incidence (RI), and better (59%) event-free survival (EFS) in recipients with upward licensing status and highly increased RI (37.5%), and reduced EFS (8%) among patients with the downward resetting status of repopulated donor NK cells after HSCT, as compared with unchanged NK cell licensing (RI 23%, EFS 47%). These trends were confirmed in adjusted multivariable models (for RI p = 6.66E-09, OR = 1.47, 95% CI 1.29-1.66 and for EFS p = 3.79E-13, OR = 1.67, 95% CI 1.50-1.84). Differences in the incidence of acute graft versus host disease (GvHD 62, 69, and 47%) and chronic GvHD (24, 44, and 15%, respectively) in three groups were insignificant. It would be rationale the preferential selection of the donors with upward licensing over downward resetting inhibitory KIR:HLA constellation and inclusion of the KIR genotyping in the donor selection algorithm for malignant patients. Further studies using enlarged cohorts of patients with more homogenous diagnosis are essential to reliably verify these preliminary data.

Beneficial effect of the CXCL12-3'A variant for patients undergoing hematopoietic stem cell transplantation from unrelated donors.

The present study aimed to assess the impact of the CXCL12 gene polymorphism (rs1801157) on clinical outcome of hematopoietic stem cell transplantation from unrelated donors. Toxic complications were less frequent among patients transplanted from donors carrying the CXCL12-3'-A allele (42/79 vs. 105/151, p=0.014 and 24/79 vs. 73/151, p=0.009, for grade II-IV and III-IV, respectively). Logistic regression analyses confirmed a role of donor A allele (OR=0.509, p=0.022 and OR=0.473, p=0.013 for grade II-IV and III-IV toxicity). In addition, age of recipients (OR=0.980, p=0.036 and OR=0.981, p=0.040, respectively) was independently protective while female to male transplantation and HLA compatibility were not significant. The incidence of aGvHD (grades I-IV) was lower in patients having A allele (52/119 vs. 113/204, p=0.043) and AA homozygous genotype (6/25 vs. 159/298, p=0.005). Independent associations of both genetic markers with a decreased risk of aGvHD were also seen in multivariate analyses (A allele: OR=0.591, p=0.030; AA homozygosity: OR=0.257, p=0.006) in which HLA compatibility seemed to play less protective role (p<0.1) while recipient age and donor-recipient gender relation were not significant. Moreover, CXCL12-3'-A-positive patients were less prone to early HHV-6 reactivation (2/34 vs. 19/69, p=0.026). The presence of the CXCL12-3'-A variant was found to facilitate outcome of unrelated HSCT.

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

Some 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.

Donor NK cell licensing in control of malignancy in hematopoietic stem cell transplant recipients.

Among cancers treated with allogeneic hematopoietic stem-cell transplantation (HSCT), some are sensitive to natural killer (NK) cell reactivity, described as the "missing self" recognition effect. However, this model disregarded the NK cell licensing effect, which highly increases the NK cell reactivity against tumor and is dependent on the coexpression of inhibitory killer cell immunoglobulin-like receptor (iKIR) and its corresponding HLA Class I ligand. We assessed clinical data, HLA and donor iKIR genotyping in 283 patients with myelo- and lymphoproliferative malignancies who underwent HSCT from unrelated donors. We found dramatically reduced overall survival (OS), progression free survival (PFS), and time to progression (TTP) among patients with malignant diseases with the lack of HLA ligand cognate with this iKIR involved in NK cell licensing in corresponding donor (events 83.3% vs. 39.8%, P = 0.0010; 91.6% vs. 47.7%, P = 0.00010; and 30.0% vs. 17.3%, P = 0.013, for OS, PFS, and TTP, respectively). The extremely adverse PFS have withstand the correction when patient group was restricted to HLA mismatched donor-recipient pairs. The incidence of aGvHD was comparable in two groups of patients. In malignant patients after HSCT the missing HLA ligand for iKIR involved in NK cell licensing in corresponding donor ("missing licensing proof") induced extremely adverse survival of the patients due to the progression of malignancy and not to the aGvHD. Avoiding the selection of HSCT donors with the "missing licensing proof" in the malignant patient is strongly advisable.

Both optimal matching and procedure duration influence survival of patients after unrelated donor hematopoietic stem cell transplantation.

Eighty-six patients suffering from hematological malignancies, immunodeficiencies, and aplastic anemias received alloHSCT from unrelated donors. Donors were selected from the BMDW files and further matching was performed according to the confirmatory typing procedure with the use of PCR SSP and that based on sequencing. The time from the clinical request of the donor search to the final decision of clinicians accepting the donor was from 0.3 to 17.8 months (median 1.6). Matching was analyzed at the allele level, and 50, 27, and 9 donor-recipient pairs were 10/10 matched, mismatched in one or more alleles, respectively. In an univariate analysis we found better survival if patients were transplanted: (i) from donors matched 10/10 (P = 0.025), (ii) not from female donor to male recipient (P = 0.037), (iii) in female donation from those with ≤1 pregnancy than multiparous (P = 0.075). Notably, it became apparent that duration of the confirmatory typing process affected the survival (HR = 1.138, P = 0.013). In multivariate analysis only the level of matching and the duration of the matching procedure significantly affected the survival. In conclusion, the duration of the matching procedure in addition to the level of matching should be considered as an independent risk factor of survival.