Molecular relapse monitoring reveals the domination of impaired NK cell education over impaired inhibition in missing KIR-ligand recognition in patients after unrelated hematopoietic stem cell transplantation for malignant diseases.

Transplantation of HLA and/or KIR mismatched allogeneic hematopoietic stem cells can lead NK cells to different states of activation/inhibition or education/resetting and change anti-tumor immunosurveillance. In this study, we used molecular relapse monitoring to investigate a correlation between either missing ligand recognition or variation of the cognate iKIR-HLA pairs with clinical outcomes in patients with hematological malignancies requiring allogeneic hematopoietic stem cell transplantation (allo-HSCT). Patients (N = 418) with acute myeloid leukemia (AML), chronic myeloid leukemia (CML), acute lymphoblastic leukemia (ALL), myelodysplastic syndrome (MDS), or lymphoma receiving T-cell repleted graft from HLA-matched or partly mismatched unrelated donors between 2012 and 2020 in our center were included in this study. Missing-ligand recognition was assessed through the presence or absence of recipients' HLA ligand for a particular inhibitory KIR (iKIR) exhibited by the donor. Inhibitory KIR-HLA pair number variation was defined by loss or gain of a new cognate pair of HLA-KIR within the new HLA environment of the recipient, compared with the donor's one. Considering the results of our research, we drew the following conclusions: (i) loss of iKIR-HLA cognate pair for C1, C2, and/or Bw4 groups led to significant deterioration of disease-free survival (DFS), molecular relapse, overall survival (OS) and non-relapse mortality (NRM) for patients undergoing allo-HSCT in the standard phase of the disease. This phenomenon was not observed in patients who underwent transplantation in advanced hematological cancer. (ii) The missing ligand recognition had no impact if the proportion of HLA mismatches was not considered; however, adjustments of HLA mismatch level in the compared groups highlighted the adverse effect of the missing ligand constellation. (iii) The adverse effect of adjusted missing ligand suggests a predominance of lost NK cell education over lost NK cell inhibition in posttransplant recipients' new HLA environment. Our results suggested that donors with the loss of an iKIR-HLA cognate pair after transplantation should be avoided, and donors who provided an additional iKIR-HLA cognate pair should be preferred in the allo-HSCT donor selection process.

Paroxysmal nocturnal hemoglobinuria: advances in the understanding of pathophysiology, diagnosis, and treatment.

In recent years, "old" paroxysmal nocturnal hemoglobinuria (PNH) has achieved new advances in terms of the understanding of its pathophysiology, modern approach to diagnostics, optimization of therapy, and dynamic development of new therapeutic agents. This review emphasizes the greater than previously recognized importance of the reduced susceptibility of PNH stem cells to apoptosis in the selection of a defective clone. Some changes in cytokine and chemokine profiles in patients with PNH have been interpreted in the context of autoimmunity and apoptosis. The classification of PNH presentations, characteristics of the functions of selected glycosylphosphatidylinositol-anchored proteins, as well as pathologies associated with hemolysis, thrombosis, and bone marrow failure are described. The current diagnostic process for various forms of PNH is presented in detail, as well as its importance in the choice of treatment and prognosis of the disease course. Determinants of modern treatment, such as strategies (complement C5 inhibitors vs hematopoietic stem cell allotransplantation), the safety and efficacy of treatment with eculizumab or ravulizumab, policy of initiation and monitoring of treatment, the criteria for response to treatment and final outcomes of treatment are described. Among the new therapeutic agents, crovalimab and C5 inhibitors at a less advanced stage of research are discussed: tesidolumab, pozelimab, zilucoplan, nomacopan, and cemdisiran. The first approved proximal complement pathway inhibitors that primarily prevent extravascular hemolysis, pegcetacoplan, danikopan, and iptacopan, are presented and their potential benefits are highlighted.

Persistent imbalance, anti-apoptotic, and anti-inflammatory signature of circulating C-C chemokines and cytokines in patients with paroxysmal nocturnal hemoglobinuria.

OBJECTIVE: Paroxysmal nocturnal hemoglobinuria (PNH) is a clonal non-malignant disease in which hematopoietic cell apoptosis may play an important pathophysiological role. Previous studies of the content of phosphatidylinositol (3,4,5)-trisphosphate (PI(3,4,5)P3) indicated the possibility of remote transmission of anti-apoptotic signals between pathological and normal hematopoietic progenitors. METHODS: The study determined the plasma levels of beta chemokines and cytokines in N = 19 patients with PNH and 31 healthy controls. The research material was peripheral blood plasma (EDTA) stored at -80 °C until the test. Beta chemokine and cytokine concentrations were tested in duplicate with Bio-Plex Pro Human Cytokine Assay (Bio-Rad, Hercules, CA, USA) using a Luminex 200 flow cytometer and xPONENT software (Luminex Corporation, Austin, TX, USA). In peripheral blood CD34+ cells we tested the proportions of PI(3,4,5)P3+ and Annexin binding apoptotic phenotype using FC and phosflow. RESULTS: Compared to the control group, the PNH group showed a significant increase in the plasma concentration of some beta chemokines and cytokines, including MIP-1alpha/CCL3, eotaxin/CCL11, MCP1/CCL2, IL4 and G-CSF. In the group of PNH patients, a significant decrease in the concentration of some cytokines was also observed: RANTES/CCL5, MIP-1beta/CCL4, PDGF-BB and IL9. At the same time, the plasma concentrations of the chemokine IP-10/CXCL10 and the cytokines IFN-gamma, TNF, IL6 and IL10 showed no significant deviations from the values for the control group. Anti-apoptotic phenotype and phosphatidylinositol (3,4,5)-trisphosphate content in PNH clone of CD34+ cells were associated with the level of CCL3 and negatively associated with CCL5, CCL4, PDGF-BB and IL9. CONCLUSIONS: This data suggest the existence of apoptotic and PI(3,4,5)P3 imbalance in PNH CD34+ cells driven by anti-apoptotic cytokine biosignature in PNH. Plasma cytokines and intracellular enzymes that regulate the phosphoinositide pathways may become a therapeutic target in PNH.

Epstein-Barr virus infections are strongly dependent on activating and inhibitory KIR-HLA pairs after T-cell replate unrelated hematopoietic stem cell transplantation, the principles, and method of pairing analysis.

Viral infections are the main cause of increased morbidity and mortality among recipients in allogeneic hematopoietic stem cell transplantation (HSCT). Natural killer (NK) cells fight virally infected cells provided directional activation of cytotoxicity. In this study, we analyzed the role of receptor-ligand pairs that include inhibitory or activating killer cell immunoglobulin-like receptors (KIRs) with their HLA class I ligands in the course of viral infections. The paper also presents an algorithm that allows performing automated inhibitory (i) KIR:HLA pairing and rechecking in the clinical setting. The obtained results indicate a significant adverse roles of reduced number of iKIR:HLA pairs (40% vs 9%; odds ratio [OR] = 6.67; P = .0057; 95% confidence interval [CI] 1.74-25.62) and the presence of activating KIR:HLA pairs (15% vs 5%, OR = 3.58, P = .028, 95% CI 1.19-10.73) in EBV infections post HSCT.

KIR specificity and avidity of standard and unusual C1, C2, Bw4, Bw6 and A3/11 amino acid motifs at entire HLA:KIR interface between NK and target cells, the functional and evolutionary classification of HLA class I molecules.

Natural killer (NK) cells make vital contributions to the immune system and the reproductive system. Notably, NK cells of donor origin can recognize and kill residual leukaemic cells and cure malignant patients in hematopoietic stem cell (HSC) transplant setting. NK cell function is regulated by KIRs that recognize cognate HLA class I molecules on target cells, depending on their amino acid residues. In review, we addressed the question of binding capacity and avidity of HLA class I molecules to different killer cell immunoglobulin-like receptors (KIRs) depending on all interacting amino acid residues both on HLA and KIR side. We searched PubMed database and analysed available HLA:KIR crystallographic data for amino acid residues in HLA molecules, those physically involved in binding KIRs (termed here the "entire KIR interface"). Within entire KIR interface, we selected five functional sequence motifs (14-19, 66-76, 77-84, 88-92 and 142-151) and classified them according to the conservation of their amino acid sequences among 8,942 HLA class I molecules. Although some conserved amino acid motifs were shared by different groups of KIR ligands, the HLA motif combinations were exclusive for the ligand groups. In 135 common HLA class I molecules with known HLA:KIR recognition, we found 54 combinations of five motifs in each of the KIR-binding interfaces (C1, C2, Bw4, A3/11) and conserved non-KIR-binding interfaces. Based on the entire KIR interface, this analysis allowed to classify 8,942 HLA class I molecules into KIR specificity groups. This functional and evolutionary classification of entire KIR interfaces provides a tool for unambiguously predicting HLA:KIR interactions for common and those HLA molecules that have not yet been functionally tested. Considering the entire KIR interface in HLA class I molecules, functional interactions of HLA and KIR can be predicted in immune responses, reproduction and allotransplantation. Further functional studies are needed on the HLA:KIR interaction variations caused by the repertoires of peptides presented by HLA molecules and KIR polymorphisms at allelic level.

Role of donor HLA class I mismatch, KIR-ligand mismatch and HLA:KIR pairings in hematological malignancy relapse after unrelated hematopoietic stem cell transplantation.

HLA are functional in cancer immunosurveillance in adaptive and innate immunity pathways. In unrelated hematopoietic stem cell transplantation (HSCT) in 688 patients with hematological malignancies we compared antitumor efficacy of transplant in three models including the level of: (a) donor-recipient HLA class I mismatch, (b) KIR-ligand mismatch, (c) post-transplant cognate HLA:KIR pairing. The effects were directly compared in multivariate models with backward elimination including all three effects in initial model. In final multivariate model HLA mismatch and KIR-ligand mismatch levels were eliminated and HLA:KIR-dependent NK cell licensing effect remained independent prognostic factor for DFS, relapse/progression incidence, and overall survival (OS). These results suggested that NK cell licensing via cognate HLA:KIR pairs is primarily functional in cancer immunosurveillance in HSCT.

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.

Clinical, Biochemical and Molecular Characteristics of the Main Types of Porphyria.

Porphyrias are diverse disorders that arise from various inherited enzyme defects in the heme biosynthesis pathway, except for porphyria cutanea tarda (PCT), in which the enzyme deficiency in most cases is acquired. The biosynthetic blocks resulting from the defective enzymes are largely expressed either in the liver or bone marrow, the sites where the majority of heme is produced. Although the pathophysiologic mechanisms of the clinical manifestations of the porphyrias are not fully understood, two cardinal features prevail: skin photosensitivity and neurologic symptoms of intermittent autonomic neuropathy, acute neurovisceral attacks, and disorders of the nervous system. The primary diagnosis of the proband is based on biochemical testing, which is not always able to identify acute porphyrias, especially in asymptomatic family carriers when heme precursors and porphyrins excretion is normal, low-normal and high-reduced values of enzyme activity overlap, and hematological diseases responsible for abnormal blood cells distribution coexist. Molecular analysis of gene mutations responsible for each type of porphyria is the best diagnostic approach for symptomatic as well as presymptomatic gene carriers.

Porphobilinogen deaminase gene mutations in Polish patients with non-erythroid acute intermittent porphyria.

BACKGROUND: Acute intermittent porphyria (AIP) is an metabolic disorder characterized by a partial deficiency of the porphobilinogen deaminase, the enzyme of heme biosynthesis. The metabolic defect in AIP involves an approximately half-normal activity of porphobilinogen deaminase (PBGD, EC 4.3.1.8), the enzyme catalyzing condensation of four porphobilinogen molecules to hydroxymethylbilane. Due to tissue-specific alternative transcript splicing, the PBGD gene mutations within the range of exons 3-15 may lead to classical AIP involving erythrocytes and all the other tissues. Mutations within intron and exon 1 may result in the so-called non-erythroid AIP in which the PBGD activity is normal in erythrocytes and diminished in other tissues. OBJECTIVES: The aim of the present study was to characterise molecular errors in the PBGD gene in Polish patients with non-erythroid AIP and to evaluate the efficacy of the DNA sequencing method in the early diagnosis of this disorder. MATERIAL AND METHODS: Twenty five members of nine non-erythroid AIP families were assessed. In each of them DNA sequencing was performed using the Big Dye Terminator Cycle Sequencing Kit v.1.1 on the Hitachi 3730 Analyzer (Applied Biosystem, USA). RESULTS: Four mutations were detected in intron 1 of the PBGD gene, including one unreported novel mutation, 33+(4-12) del AGTGCTGAG, of an unknown biological mechanism, and three previously described mutations, i.e. 33+1 G > A, 33+2 T > C, 33+5 G > C, responsible for abnormal transcript splicing in the area of exon 1. Of 14 asymptomatic members of proband families in 6 subjects were diagnosed with AIP, and in 8 the AIP was excluded based on the DNA sequencing method. CONCLUSIONS: DNA sequencing based analysis is the only reliable method for correct diagnosis of asymptomatic non-erythroid AIP patients with normal urinary excretion of heme precursors. The mutations found in Polish patients with non-erythroid AIP represented those of splice defect and resulted in abnormal exon 1 splicing.

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.

[Acute intermittent porphyria and oral contraception. Case report]. / Ostra przerywana porfiria i doustna antykoncepcja opis przypadku.

BACKGROUND: Acute intermittent porphyria is the most common type of porphyria occurring in Poland. Its characteristic feature is periods of remissions and aggravations. Aggravation or an attack of the disease is caused by many endogenous and exogenous factors, among others by hormonal contraceptives. CASE REPORT: This article describes the case of an acute intermittent porphyria attack in a 28 years old female patient resulting from the use of a few, contraindicated drugs (metamizole, nospa, desogestrel in case of porphyria, urinary tract infection, as well as a spontaneous abortion two months earlier). The attack included abdominal pain, vomiting, reduction in muscle strength in limbs and it was complicated by seizures caused by hyponatraemia. High excess haem precursors in urine was observed. During hospitalization, the patient ceased to take harmful drugs and she was given haem arginate, glucose and symptomatic drugs, and she recovered completely. CONCLUSION: In the described case there were a few porphyrogenous factors whose action was observed, among which the most important was desogestrel. Due to this conclusion, a change in contraceptive therapy that would exclude hormonal contraception was suggested.

Molecular study of the hydroxymethylbilane synthase gene (HMBS) among Polish patients with acute intermittent porphyria.

Acute intermittent porphyria (AIP), an autosomal dominant disorder of heme biosynthesis, is due to mutations in hydroxymethylbilane synthase (HMBS; or porphobilinogen deaminase, PBGD) gene. In this study, we analyzed 20 Polish patients affected by AIP and we were able to characterize seven novel mutations. A nonsense mutation (Y46X), two frameshift mutations (315delT and 552delT) and a 131bp deletion (nucleotides 992-1123) give rise to truncated proteins. A donor splice site mutation IVS12+2T>C predicts skipping of exon 12. A missense mutation (D61Y) was identified in two apparently unrelated patients with a clearly clinical indication of AIP. An inframe 3-bp deletion (278-280delTTG) results in the removal of V93 from the enzyme. In addition to the novel mutations, nine previously described HMBS gene mutations-R26H, G111R, IVS7+1G>A, R149X, R173Q, 730-731delCT, R225X, 982-983delCA and G335D-were identified in this cohort. Our results demonstrate that molecular analysis of the PBGD gene is a more reliable method comparing to enzymatic assay in the diagnosis of AIP. Although more than 170 different mutations are known to the HMBS gene so far, over 40% of all mutations identified among the Polish AIP patients of this study are novel mutations, indicating the heterogeneity of molecular defects causing AIP.