There is limited information regarding the influence of KIR genotype, compared to the HLA system, in haploidentical haematopoietic stem cell transplantation (haplo-HSCT). This study aimed to determine the frequencies of KIR genotypes in Spanish haematologic patients undergoing haplo-HSCT. A study was conducted on 113 oncohaematological patients and their donors, treated across five centres that are members of the Spanish Working Group in Histocompatibility and Transplant Immunology (GETHIT) and the Spanish Haematopoietic Transplantation and Cell Therapy Group (GETH-TC). KIR typing was performed using PCR-rSSO or PCR-SSP. KIR genotypes were identified using the KIR Allele Frequency Net Database. Among donors, the most frequent KIR genotypes were Type 1 (28.3%), Type 2 (12.4%) and Type 4 (10.6%). In patients, Genotypes 1 (23.9%), 4 (23%) and 2 (14.2%) were most prevalent. Donors exhibited AA centromeric (46%) and telomeric (59.3%) types, while patients had a higher AB centromeric frequency (52.2%). Differences were observed in the BB centromeric type (3.5% patients; 16.8% donors, p = 0.002). The AB KIR genotype was the most common (70.8% donors; 75.2% patients). Most were classified as 'neutral' (61.9% donors; 73.5% patients). B-content score1 was the most common (48.7% patients; 33.6% donors). Notably, classification as best was rare (2.7% patients; 16.8% donors, p = 0.002). The study highlights the distribution of KIR genotypes in haplo-HSCT patients and donors, with Genotypes 1, 2 and 4 being the most prevalent. AB KIR genotypes and B-content score 1 were dominant. Moreover, KIR genotypes ID may serve as criteria for future investigation about the immunogenetic predisposition to malignant haematological diseases.

Identification of the novel HLA-C*05:279 allele that differs from C*05:01:01:11 by two nucleotide substitutions.

A novel HLA‐A*33 allele, officially designated HLA‐A*33:237 , was identified by next‐generation sequencing.

A synonymous nucleotide substitution in exon 3 results in the novel HLA-DQA1*02:01:09:01 allele.

The impact of human leukocyte antigen (HLA)-mismatching on the early appearance of subclinical inflammation (SCI) in low-immunological-risk kidney transplant (KT) recipients is undetermined. We aimed to assess whether HLA-mismatching (A-B-C-DR-DQ) is a risk factor for early SCI. As part of a clinical trial (Clinicaltrials.gov, number NCT02284464), a total of 105 low-immunological-risk KT patients underwent a protocol biopsy on the third month post-KT. As a result, 54 presented SCI, showing a greater number of total HLA-mismatches (p = 0.008) and worse allograft function compared with the no inflammation group (48.5 ± 13.6 vs. 60 ± 23.4 mL/min; p = 0.003). Multiple logistic regression showed that the only risk factor associated with SCI was the total HLA-mismatch score (OR 1.32, 95%CI 1.06–1.64, p = 0.013) or class II HLA mismatching (OR 1.51; 95%CI 1.04–2.19, p = 0.032) after adjusting for confounder variables (recipient age, delayed graft function, transfusion prior KT, and tacrolimus levels). The ROC curve illustrated that the HLA mismatching of six antigens was the optimal value in terms of sensitivity and specificity for predicting the SCI. Finally, a significantly higher proportion of SCI was seen in patients with >6 vs. ≤6 HLA-mismatches (62.3 vs. 37.7%; p = 0.008). HLA compatibility is an independent risk factor associated with early SCI. Thus, transplant physicians should perhaps be more aware of HLA mismatching to reduce these early harmful lesions.

One hundred and sixty-one patients underwent haploidentical stem cell transplantation (haploSCT) with thiotepa, busulfan, and fludarabine conditioning followed by post-transplantation cyclophosphamide (PTCy) (on days +3 and +4) and tacrolimus as graft-versus-host disease prophylaxis. Forty-two percent of patients had a high or very high revised Disease Risk Index (rDRI), 55% had an European Society for Blood and Marrow Transplantation risk score (EBMT-RS) ≥4, and 36% had an age-adjusted Hematopoietic Cell Transplant Comorbidity Index (HCT-CI-age) score ≥3. Each of these was considered an unfavorable score. Using the pretransplantation unfavorable scores that had an independent impact on each transplantation outcome studied in multivariate analysis allowed for better stratification of patient outcomes. Thus, the 3-year overall survival (OS) in patients with 0, 1, 2, and 3 unfavorable scores was 86%, 56%, 36%, and 24%, respectively. Nonrelapse mortality (NRM) was negatively impacted by the EBMT-RS and the HCT-CI-age score (3-year NRM in patients with 0, 1, and 2 unfavorable scores was 12%, 33%, and 43%, respectively), whereas the EBMT-RS and the rDRI had an impact on the 3-year relapse incidence (8%, 18%, and 41% in patients with 0, 1, and 2 unfavorable scores, respectively). In conclusion, our study shows that combining 2 or 3 of these well-defined pretransplantation scores improves the ability to predict transplantation outcomes in the setting of haploSCT with PTCy.

The impact of corticosteroid withdrawal on medium-term graft histological changes in kidney transplant (KT) recipients under standard immunosuppression is uncertain. As part of an open-label, multicenter, prospective, phase IV, 24-month clinical trial (ClinicalTrials.gov, NCT02284464) in low-immunological-risk KT recipients, 105 patients were randomized, after a protocol-biopsy at 3 months, to corticosteroid continuation (CSC, n = 52) or corticosteroid withdrawal (CSW, n = 53). Both groups received tacrolimus and MMF and had another protocol-biopsy at 24 months. The acute rejection rate, including subclinical inflammation (SCI), was comparable between groups (21.2 vs. 24.5%). No patients developed dnDSA. Inflammatory and chronicity scores increased from 3 to 24 months in patients with, at baseline, no inflammation (NI) or SCI, regardless of treatment. CSW patients with SCI at 3 months had a significantly increased chronicity score at 24 months. HbA1c levels were lower in CSW patients (6.4 ± 1.2 vs. 5.7 ± 0.6%; p = 0.013) at 24 months, as was systolic blood pressure (134.2 ± 14.9 vs. 125.7 ± 15.3 mmHg; p = 0.016). Allograft function was comparable between groups and no patients died or lost their graft. An increase in chronicity scores at 2-years post-transplantation was observed in low-immunological-risk KT recipients with initial NI or SCI, but CSW may accelerate chronicity changes, especially in patients with early SCI. This strategy did, however, improve the cardiovascular profiles of patients.

Background. In haploidentical stem cell transplantation (SCT), the "ideal donor" selection is not performed in a standardized way according to killer cell immunoglobulin like receptor (KIR) genotype expressed by potential donors. The aim of this study was to evaluate the relevance of MR genotype in a series of patients submitted to haploidentical SCT in our center. Methods. We retrospectively analyzed 30 patients that were prepared with the use of a conditioning regimen including thiotepa-busulfan-fludarabine with high doses of post-transplantation cyclophosphamide (CyPT) and tacrolimus as graft-versus-host disease (GVHD) prophylaxis. We analyzed the impact of the KIR genotype variables (donor AA/Bx haplotype, donor B content, MR inhibitor mismatches, and mismatching in MR ligands in the graft-versus-host direction and the host-versus-graft direction) on overall survival, GVHD-free survival, and event-free survival. Results. Statistical significance was found for the presence of mismatches on KIR ligands in the graft-versus-host direction in relation to the diagnosis of chronic GVHD (54% vs 100%; P = .004). Significance was also found for the effect of the donor presence AA or Bx haplotype in relation to the diagnosis of chronic GVHD (50% vs 86%; P = .033). Conclusions. MR genotyping can provide useful information that can help us with the right donor choice for haploidentical SCT without T-cell depletion with high doses of CyPT. Donors with Bx haplotype that do not show MR ligand incompatibilities in the graft-versus-host direction may provide a lower risk of GVHD.

Introduction. We have recently reported that some lymphocyte populations do not maintain the same proportion in kidney graft blood as in peripheral blood, despite a stable function of the transplanted kidney. These results suggest that a comparative study between leukocyte cells from graft blood and those obtained from peripheral blood could provide information about the inflammatory state of the transplanted organ. In this work we selected the population of CD4+ lymphocytes and monocytes expressing CXCR3 to test this hypothesis. Material and Methods. The study was performed by flow cytometry during month 3, 6, and 12 after transplantation in 58 patients who received an isolated kidney transplant and the same immunosuppressive regimen. The peripheral blood sample was obtained by venipuncture and the graft blood by fine needle aspiration. Results. We found a significant percentage decrease in CXCR3+ monocytes throughout the first year of transplantation in peripheral blood (15.9 +/- 20.7 vs. 12.6 +/- 12.4 vs. 6.3 +/- 9.0, at 3, 6, and 12 months, respectively; P = .001), whereas the percentage of CXCR3+ monocytes in graft blood did not change over this period. This situation resulted in a significant percentage difference between the CXCR3+ monocytes from the graft blood and those from the peripheral blood at the sixth (15.8 +/- 8.1 vs. 12.6 +/- 12.4, respectively; P=.008) and 12th months (12.9 +/- 8.1 vs. 6.3 +/- 9.0, respectively; P < .001). Conclusions. Therefore, we can conclude that the significant percentage increase of CXCR3+ monocytes in graft blood with respect to peripheral blood suggests the presence of inflammatory activity despite renal function being stable during the second half of the first year post-transplantation.

La homocistinuria es un error innato del metabolismo de la metionina con una alta tasa de morbimortalidad. Mutaciones en la cistationina beta-sintetasa son la causa más frecuente de homocistinuria, conocida esta como homocistinuria clásica. Hay descritas más de 150 mutaciones diferentes, de las cuales la más prevalente en España es la T191M. La detección mediante cribado neonatal puede prevenir las complicaciones más graves de la enfermedad y posibilitar un desarrollo cognitivo normal. Presentamos un caso de homocistinuria clásica debida a la mutación T353M, con fenotipo no respondedor a piridoxina.