Antigen DRB1 Research Articles

High maternal-fetal HLA eplet compatibility is associated with severe manifestation of preeclampsia.

Preeclampsia is responsible for more than 70 000 and 500 000 maternal and fetal deaths, respectively each year. Incomplete remodelling of the spiral arteries in placenta is the most accepted theory of preeclampsia pathogenesis. However, the process is complexed with immunological background, as pregnancy resembles allograft transplantation. Fetus expresses human leukocyte antigens (HLA) inherited from both parents, thus is semiallogeneic to the maternal immune system. Therefore, induction of fetal tolerance is crucial for physiological outcome of pregnancy. Noteworthy, the immunogenicity of discordant HLA antigens is determined by functional epitopes called eplets, which are continuous and discontinuous short sequences of amino acids. This way various HLA molecules may express the same eplet and some HLA incompatibilities can be more immunogenic due to different eplet combination. Therefore, we hypothesized that maternal- fetal HLA incompatibility may be involved in the pathogenesis of gestational hypertension and its progression to preeclampsia. We also aimed to test if particular maternal-fetal eplet mismatches are more prone for induction of anti- fetal HLA antibodies in gestational hypertension and preeclampsia. High resolution next-generation sequencing of HLA-A, -B, -C, -DQB1 and -DRB1 antigens was performed in mothers and children from physiological pregnancies (12 pairs) and from pregnancies complicated with gestational hypertension (22 pairs) and preeclampsia (27 pairs). In the next step HLA eplet identification and analysis of HLA eplet incompatibilities was performed with in silico approach HLAMatchmaker algorithm. Simultaneously maternal sera were screened for anti-fetal HLA class I, class II and anti-MICA antibodies with Luminex, and data were analyzed with HLA-Fusion software. We observed that high HLA-C, -B, and DQB1 maternal-fetal eplet compatibility was associated with severe preeclampsia (PE) manifestation. Both quantity and quality of HLA epletmismatches affected the severity of PE. Mismatches in HLA-B eplets: 65QIA+76ESN, 70IAO, 180E, HLA-C eplets: 193PL3, 267QE, and HLA-DRB1 eplet: 16Y were associated with a mild outcome of preeclampsia if the complication occurred. High HLA-C, HLA-DQB1 and HLA-B eplet compatibility between mother and child is associated with severe manifestation of preeclampsia. Both quantity and quality of maternal-fetal HLA eplet mismatches affects severity of preeclampsia.

Typing of HLA-A, -B and DRB1 antigens in clinical practice in patients of the Rostov population for early diagnosis of rheumatoid arthritis

Objective: a retrospective analysis of the results obtained by typing HLA-A, -B antigens and HLA DRB1 allele groups in patients with rheumatoid arthritis (RA) in the Rostov population.Materials and methods: typing of patients with rheumatic inflammatory diseases who were on inpatient treatment in the rheumatology department of the SBI “OKB No. 2” was carried out in the LITT SBI RO "BTS" in 2019-2020. 41 patients (9 men, 32 women, median age — 42 years) were diagnosed with RA. All patients were typed by HLA-DRB1 alleles by real-time polymerase chain reaction with DNA-TECH reagents (Russia). To isolate DNA, a set of Sample-Rapid-Genetics was used by NPO DNA Technology LLC. 39 patients were typed аccording to HLA-A, -B. Typing was carried out by a standard lymphocytotoxic test with DILEN reagents (Czech Republic). Lymphocytes were isolated in a density gradient of “Lympholot”, DILEN company. The control group consisted of healthy residents of the Rostov population (donors of the hematopoietic stem cell registry).Results: a retrospective analysis showed that HLA DRB1*04 occurs in 46.3% of the Rostov population with RA, in 61.1% of the seropositive RA group (control — 20%). There was a decrease in the frequency of HLA DRB1*13 (9.7%) compared to the control (24.4%).Conclusions: the high level of reliability (p<0.001) of the increase in the frequency of HLA DRB1*04 alleles confirms their associative relationship with RA in the Rostov population. A decrease in the frequency of HLA DRB1*13 indicates the protective function of these alleles in RA. Typing results are important for early diagnosis of RA.

Genetic Variation and Population Differentiation in the Bovine Lymphocyte Antigen DRB3.2 Locus of South African Nguni Crossbred Cattle.

Simple SummaryIndigenous cattle breeds are important to their native environment as they confer significant and often unique adaptability traits. The Nguni is one such breeds that is indigenous to the Southern African region. This breed confers resistance to thermal stress and diseases, amongst other factors. The bovine major histocompatibility complex is an important region, which codes for alleles that have been associated with a plethora of diseases. In the current study, the genetic diversity within this region was assessed in Nguni crossbred cattle. This was done to detect the gene pool of the Nguni breed, and to identify genes that might be important within this breed. The populations displayed a high degree of genetic diversity, and some alleles were common throughout the populations and accounted for a significant portion of the total alleles. This high genetic diversity could account for the great adaptability of the Nguni breed to Southern Africa. The bovine lymphocyte antigen (BoLA-DRB3) gene is an important region that codes for glycoproteins responsible for the initiation of an immune response. BoLA-DRB3 alleles have been demonstrated to be associated with disease resistance/tolerance. Therefore, great genetic diversity is correlated with better adaptation, fitness, and robustness. The current study was conducted to assess the population genetic structure of the BoLA-DRB3 gene in Nguni crossbred cattle using polymerase chain reaction-sequence based typing (PCR-SBT). High genetic diversity was detected, with 30 alleles, 11 of which are novel to the study. Alleles DRB3*0201, DRB3*0701, DRB*0901, and DRB*1601 were present in all populations and accounted for nearly around 50% of all observed alleles. A mean genetic diversity (HE) of 0.93 was detected. The high overall genetic diversity is possibly associated with pathogen-assisted selection and heterozygote advantage. Such high diversity might explain the hardiness of the Nguni crossbred cattle to the Southern African region. Low population genetic structure was identified (FST = 0.01), suggesting possible gene flow between populations and retention of similar alleles. The study was undertaken to bridge the dearth of such studies in South African breeds and it is imperative for effective sustainability of indigenous breeds and the implementation of effective breeding strategies.

Comparitive Genome Sequence Analysis of Bovine Lymphocyte Antigen BoLA DRB3.2 Alleles in Deoni and Ongole (Bos indicus) Cattle Breeds of India

Background: India, a major livestock region of the Asian countries is rich in animal genetic resources having special qualities of hardy nature, resistance to many diseases and adopted to adverse climatic conditions. The cattle MHC, Bovine Lymphocyte Antigen DRB3 (BoLA-DRB3) is considered to be a major gene linked with disease resistance traits of Indian cattle. Methods: The present study was carried out to sequence the BoLA-DRB3.2 alleles in Deoni and Ongole breeds of Indian cattle. PCR RFLP analysis of the BoLA-DRB3.2 alleles in Deoni (n=51) and Ongole (n=60) cattle using three different restriction enzymes RsaI, BstYI and HaeIII to find out the possible restriction pattern. Based on the combined allelic patterns, each sample was further analyzed by PCR- SBT technique to detect the SNP variations present in BoLA-DRB3.2 alleles.Result: The PCR RFLP analysis revealed that the highest frequent alleles are *6 (0.216) and *15 (0.225) in Deoni and Ongole breeds of cattle, respectively. The second-highest frequency was observed for BoLA alleles *11 and *6 which were present at a frequency of 0.167 and 0.200 in Deoni and Ongole breeds of cattle, respectively. To get the complete picture of polymorphic pattern of BoLA-DRB3.2 allele direct sequencing was carried out for each plymorphic pattern. The interesting feature noticed in the Ongole breed was that at position 91 and 133 of the sequence, it had both A and G nucleotides in contrast to Bos taurus breed, which had only TT nucleotides. The sequence analysis of BoLA-DRB3 exon 2 between two breeds revealed that there are numerous variations in exon 2, whatever variation, that lead to different mobility shift and band pattern in gels. Deoni and Ongole breeds of cattle had similar variations at positions 94, 134, 211, 235 and 258noticed due to the unique nature of native breeds.

Rapidly expanded partially HLA DRB1–matched fungus-specific T cells mediate in vitro and in vivo antifungal activity

AbstractInvasive fungal infections are a major cause of disease and death in immunocompromised hosts, including patients undergoing allogeneic hematopoietic stem cell transplant (HSCT). Recovery of adaptive immunity after HSCT correlates strongly with recovery from fungal infection. Using initial selection of lymphocytes expressing the activation marker CD137 after fungal stimulation, we rapidly expanded a population of mainly CD4+ T cells with potent antifungal characteristics, including production of tumor necrosis factor α, interferon γ, interleukin-17, and granulocyte-macrophage colony stimulating factor. Cells were manufactured using a fully good manufacturing practice–compliant process. In vitro, the T cells responded to fungal antigens presented on fully and partially HLA-DRB1 antigen–matched presenting cells, including when the single common DRB1 antigen was allelically mismatched. Administration of antifungal T cells lead to reduction in the severity of pulmonary and cerebral infection in an experimental mouse model of Aspergillus. These data support the establishment of a bank of cryopreserved fungus-specific T cells using normal donors with common HLA DRB1 molecules and testing of partially HLA-matched third-party donor fungus-specific T cells as a potential therapeutic in patients with invasive fungal infection after HSCT.

Polymorphism of BoLA DRB3.2 Gene in Indian Holstein Crossbred Cows using PCR-RFLP

Bovine lymphocyte antigen DRB3.2 (BoLA–DRB3.2) gene encodes for the beta chain of the major histocompatibility complex (MHC) class II molecule in cattle, which is a glycoprotein present on the surface of antigen-presenting cells. The objective of the present study was to genotype the BoLA-DRB3.2 locus in Holstein Crossbred cattle (n = 40) by PCR-RFLP. The 304bp amplified region was separately digested with restriction endonucleases Hae III and Bst YI. Seven BoLA-DRB 3.2 genotypes were detected by digesting with Hae III. The frequencies of the genotypes were: 0.475, 0.225, 0.050, 0.100, 0.050, 0.050 and 0.050 for the genotype AA, AB, AE, BB, DD, EE and II, respectively. Digestion with Bst YI yielded three genotypes AA, AB and BB with frequency of 0.050, 0.625 and 0.325. On the basis of the above results it can be concluded that the DRB3.2 gene was found to be highly polymorphic in the crossbred cattle population

BoLA-DRB3 gene as a marker of susceptibility and resistance of the Ukrainian black-pied and red-pied dairy breeds to mastitis

The major histocompatibility complex (MHC) determines the immune response, and the MHC genes are promising candidate genes for identifying associations with diseases. The decisive role in the resistance of cattle to diseases belongs to the major histocompatibility complex of (BoLA). The BoLA system consists of several jointly operating genes that provide antigen presentation by MHC system molecules followed by an immune response to pathogenic microorganisms. The most functional is the BoLA-DRB3 gene. Its exon 2 is highly polymorphic and encodes the peptide antigen-binding cleft. Alleles, for which a close connection with disease susceptibility or disease resistance has been detected, are considered as DNA markers. These play a decisive role in the breeding of cattle to create herds resistant to diseases, including mastitis. This paper presents the results of a study of BoLA-DRB3 gene polymorphism in two commercial cattle breeds: the Ukrainian black-pied dairy (UBPD) and the Ukrainian red-pied dairy (URPD) and its association with mastitis. The UBPD and the URPD cows were genotyped at the bovine lymphocyte antigen DRB3.2 locus by a genotyping system that used polymerase chain reaction and restriction fragment length polymorphisms (PCR-RLFP). In 276 UBPD cows, 32 BoLA-DRB alleles have been found. Six alleles (*03, *08, *10, *22, *24 and *28) were identified with a frequency of more than 5% (total amount of 50.4%). The allele BoLA-DRB3.2*24 was the most frequent (19.2%). In the UBPD population (n = 162), four BoLA-DRB3.2 alleles are truly associated with mastitis: *24 and *26 with susceptibility and *13 and *22 with resistance. In 117 URPD cows, 22 alleles were identified, of which the most frequent were *07, *22, *11, *24, *01, *03 and *16 (total frequency 64.5%). Allele BoLA-DRB3.2*07 (present in 25.6% of cows) was the most commonly found. In the URPD population studied, four alleles truly associated with mastitis were identified. Animals susceptible to the disease had alleles *07 and *08, and resistant animals had alleles *22 and *24. Breeding activities for the creation of cattle resistant to mastitis using alleles of the BoLA-DRB3 gene are much more effective than treatment and special care for animals. Similar research should be carried out for other Ukrainian breeds in relation to various diseases (leukemia, necrobacteriosis, etc.).

Childhood multiple sclerosis: clinical features and recent developments on treatment choices and outcomes.

Multiple sclerosis (MS) is an inflammatory idiopathic autoimmune disease causing demyelination of central nervous system (CNS). The incidence of pediatric MS is relatively rare, affecting 0.2 to 0.64/100,000 subjects; cases with MS onset before age 10-12 years, account for less than 1% of all MS cases, while 2.7 to 10.5% of all MS cases worldwide are seen in children <18 years of age, with a strong female preponderance. The disease course of MS varies from a benign type with relatively low level of disability after a long duration (15 years) of the disease, to a malignant type of MS with severe disability or even death within few months following onset. Diagnostic criteria for pediatric MS include ≥ 2 clinical events involving more areas of CNS inflammation in the absence of encephalopathy, separated by > 30 days, along with the involvement of brainstem. Pediatric MS generally presents relapsing-remittent form of MS, with majority of the patients recovering from the first attack. Major histocompatibility complex, more specifically, mutations in the human leukocyte antigen (HLA) DRB1*15 allele, are considered most important genetic factors that are contributory to the disease. Treatment choices for pediatric MS include many disease-modifying therapies (DMT) that are currently being used for adult MS and these are interferon-β 1a/1b (IFN-β1a/1b), glatiramer acetate, teriflunomide, dimethyl fumarate, alemtuzumab, etc. However, most of these have not gone through complete testing in randomized, placebo-controlled clinical trials for pediatric MS and are being prescribed off-label by clinicians. As these studies are progressing, it is important to address if these approaches of treating pediatric MS patients have any long-term impact on patients, in particular, physical, cognitive, developmental and social outcomes of the children.

Relationship between human leukocyte antigen DRB1 and psoriasis in Iraqi patients.

Objectives:To investigate the role of Human leukocyte antigen (HLA) Class II DRB1 in susceptibility to psoriasis in Iraqi patients.Methods:A cross-sectional comparative study including 40 patients with psoriasis attending the Department of Dermatology, Al-Kindy teaching hospital in Baghdad, Iraq, between September 2013-2015. Patient selection was carried out by the dermatologists. Ninety healthy individuals were included in the study. Human leukocyte antigen genotyping was carried out by the sequence specific oligonucleotide (SSO) method using Auto LiPA 48 (Innogenetics, Belgium) in the HLA typing research unit of the Al-Kindy College of Medicine, Baghdad, Iraq.Results:There is an increased frequency of HLA-DRB1*0102, *0306 in psoriatic patients with psoriasis p-values=0.001, confidence interval(CI)=2.492-37.487 and odds ratio(OR)=9.666. Human leukocyte antigen-DRB1*1101 is significantly associated with plaque-type psoriasis with p=0.0434, CI=1.04-1.69, and OR=4.2. Human leukocyte antigen-DRB1*0102 is significantly associated with other types of psoriasis with p=0.018, CI=0.0223-0.701, and OR=0.125.Conclusion:Human leukocyte antigen-DRB1*0102 and *0306 are significantly associated with psoriasis. Human leukocyte antigen-DRB1*1101 is significantly associated with plaque-type psoriasis. Human leukocyte antigen-DRB1*0102 is significantly associated with other types of psoriasis rather than plaque-type psoriasis.

P237 Specific pattern of non-specific ANTI-HLA antibody reactivity?

Solid phase assays (SPAs) have significantly improved our ability to assess the presence of anti-HLA antibody (Abs) that would be deleterious to the allograft post-transplant. SPAs have also demonstrated increased specificity and sensitivity for alloantibody detection. However, several studies have identified intrinsic and extrinsic factors that negatively impact the reliability of SPAs. Thus, substances in sera that inhibit/interfere with the Abs binding have been identified. In addition, presence of denatured HLA antigens and/or inconsistent antigen density on latex beads has been noted. These factors coupled with the increased sensitivity of the SPAs could lead to false positive/false negative results. In the present study, using single antigen beads (SAB), we demonstrate the detection of a highly specific pattern of HLA Class II alloantibodies (MFI > 1,000) against a small subset of DRB1, DRB3 and DP antigens. What is remarkable about this pattern is that a near identical profile of alloantibodies was detected in at least 6 patients (5 pre- and 1 post-transplant) and was conserved over time. Thus, Abs against the following antigens (ranked from highest MFI to lowest MFI; DR52 (03:01) – DR14:02 – DP10 – DR16:01 – DR8 - DR14:54 – DR9 – DR16:02 – DR14:01 – DP13 – DP19 – DR13) were identified in all the patients. An epitope that would help explain this pattern of reactivity could not be identified. To confirm this pattern, the sera were tested using SAB from another vendor. This pattern was completely absent, suggesting that the observed reactivity was non-specific. However, pretreatment of sera with a variety of products known to reduce interfering substances did not alter the reactivity pattern suggesting that it was “real”. Testing of sera for the presence of HLA Class I and II Abs using screening beads (each coated with multiple HLA antigens) confirmed the observations made with SAB further suggesting that the observed reactivity was “real”. Finally, surrogate flow crossmatches with donor cells expressing one or more corresponding antigens were largely T- and B-cell negative suggesting that the observed reactivity was most likely non-specific (surreal?). This study underscores the complexity involved in interpreting and then assigning presence/absence of anti-HLA alloantibodies using the highly sensitive SPAs.

Genotyping Applications for Transplantation and Transfusion Management: The Emory Experience.

Current genotyping methodologies for transplantation and transfusion management employ multiplex systems that allow for simultaneous detection of multiple HLA antigens, human platelet antigens, and red blood cell (RBC) antigens. The development of high-resolution, molecular HLA typing has led to improved outcomes in unrelated hematopoietic stem cell transplants by better identifying compatible alleles of the HLA-A, B, C, DRB1, and DQB1 antigens. In solid organ transplantation, the combination of high-resolution HLA typing with solid-phase antibody identification has proven of value for highly sensitized patients and has significantly reduced incompatible crossmatches at the time of organ allocation. This database-driven, combined HLA antigen/antibody testing has enabled routine implementation of "virtual crossmatching" and may even obviate the need for physical crossmatching. In addition, DNA-based testing for RBC antigens provides an alternative typing method that mitigates many of the limitations of hemagglutination-based phenotyping. Although RBC genotyping has utility in various transfusion settings, it has arguably been most useful for minimizing alloimmunization in the management of transfusion-dependent patients with sickle cell disease or thalassemia. The availability of high-throughput RBC genotyping for both individuals and large populations of donors, along with coordinated informatics systems to compare patients' antigen profiles with available antigen-negative and/or rare blood-typed donors, holds promise for improving the efficiency, reliability, and extent of RBC matching for this population.

Distribution of HLA Class II Antigen in Renal Transplant Patients and Donors Visiting Tertiary Care Hospital of Karnataka State in South India

Renal transplantation is the most successful treatment option for chronic renal failure patients. But success of any transplantation depends on HLA antigen matching between the recipient and the donor. This study is the first report from Karnataka state of South India to find out distribution of HLA-class II antigens in live renal transplant recipients and donors visiting a tertiary care hospital. In this study, HLA-DR allele frequencies were studied in 314 renal transplant recipients and donors visited our hospital, during 2005–2013. HLA tissue typing was done by polymerase chain reaction using sequence specific primers. Then antigen frequencies were obtained and analyzed. A total of 32 HLA-DRB1 alleles were identified in the renal transplant recipients and donors. High frequency DRB1 alleles found in our patients and donors were DRB1 * 15(25.4%), DRB1 * 14(12.2%), DRB1 * 04(11.3%), DRB1 * 13(10.2%), DRB1 * 07(8.3%). DRB1 * 15 allele was the most frequent DRB1 antigen in both males and females. Also we have found that females outnumbered males among the donors. The results showed significant heterogeneity in HLA-DRB1 alleles. The most frequent HLA-DRB3, DRB4, DRB5 alleles we observed are DRB3 * 01/02, DRB4 * 01, DRB5 * 01/02 respectively.

In silico identification and characterization of putative kuruma prawn (Marsupenaeus japonicus) allergens

Background: Prawn is one of the major sources of shellfish allergens, which will induce mild to severe allergic reactions. Aim: The objective of this study was to predict putative allergens and its characteristics present in Marsupenaeus japonicus through an in silico approach. Materials And Methods: In this present study, in silico tools, RaptorX, Bepipred Linear Epitope and Parker Hydrophilicity Prediction method, and MHC2Pred were used to predict the putative and cross-reactive allergens, tertiary and secondary structures, B-cell linear epitopes, and T-cell epitopes, respectively. Results: As a result, eight putative and cross-reactive allergens including tropomyosin fast isoform, arginine kinase, sarcoplasmic calcium binding protein, myosin light chain, chymotrypsin like proteinase, superoxide dismutase, cathepsin B, and trypsin were predicted by analyzing the protein sequences of M. japonicus. Furthermore, five amino acids (Ala, Ser, Asn, Gly, and Lys) play a vital role in immunoglobulin E binding allergenic epitope. At least one of them was found in the predicted B-cell epitope for each of the predicted putative allergens. Moreover, the predicted T-cell epitopes were highly associated with human leukocyte antigen (HLA) DRB1*0101 and HLA-DRB1*0901 alleles while mediating T-cell immune responses. Conclusion: These results can be utilized to contribute in peptide immunotherapy and reduce the allergic diseases related to shellfish.

Transplant-Associated Thrombotic Microangiopathy: Prevalence, Prognostic Factors and Treatment Outcomes in Unrelated Allogeneic Transplant for Hematologic Diseases

Introduction: Transplant-associated thrombotic microangiopathy (TA-TMA) represents a devastating and life-threatening complication occurring more frequently in allogeneic compared to autologous hematopoietic cell transplantation (HCT). Although it has been a well-recognized syndrome for decades, our understanding in terms of epidemiology and more importantly, treatment options remains unclear. Therefore, we aimed to retrospectively investigate the incidence of TA-TMA in patients undergone HCT from unrelated donors and identify prognostic factors and treatment outcomes.Methods: We enrolled consecutive patients who underwent HCT from unrelated donors from 2003 to 2015. TA-TMA diagnosis was based on EBMT (European Bone Marrow Transplantation) criteria: increased (>4%) schistocytes in peripheral blood, thrombocytopenia, increased lactade dehydrogenase, decreased Hb. Anti-thymocyte globulin (ATG, rabbit) was used as standardised part of the conditioning in almost all patients (total dose of 5-7.5mg/kg). Prophylaxis for graft-versus-host disease (GVHD) consisted of cyclosporine or tacrolimus plus methotrexate in myeloablative and mycophenolate mofetil plus cyclosporine in reduced intensity conditioning transplants. Upon identification of TA-TMA, all possible causative factors were fully investigated. The mainstay of treatment strategy was withdrawal of calcineurin inhibitors, plasma infusion and plasma exchange combined with corticosteroid administration and in refractory cases, humanized anti-CD20 monoclonal antibody (Rituximab).Results: In total, we studied 179 patients, 74 male:105 female, aged 37±14 years, who underwent HCT from matched HLA A/B/C/DRB1 (8/8, n=88) and allele or antigen mismatched (n=91) grafts. Grafts derived from peripheral blood (157), bone marrow (18) and umbilical stem cells (4). Conditioning regimens were myeloablative (139), reduced intensity (28) and toxicity (12). Median follow-up was 11.5 (0.1-147.4) months.TA-TMA was diagnosed in 29 (16.2%) patients, 12 male:17 female, aged 34±12 years, 78 (9-721) days post-HCT for acute leukemia (21), Hodgkin (3) and non-Hodgkin (1), lymphoma, MDS (2), aplastic anemia (1) and MPN (1). Conditioning regimens were myeloablative in 24 (12 based on total body irradiation/TBI) and reduced intensity in 5 patients. Among patients with TA-TMA, 10 (34%) presented severe (grade III-IV) acute GVHD, 15 (52%) extensive chronic GVHD, 12 (41%) bacterial, 2 (7%) fungal and 21 (71%) viral (Cytomegalovirus and/or Epstein-Barr viremia) infectious episodes.In univariate analysis, age, gender, diagnosis, disease phase, previous lines of treatment, conditioning (intensity and TBI-based), ABO and HLA incompatibility, infections, acute and chronic GVHD were studied. The presence of TA-TMA was associated with severe acute and extensive chronic GVHD (p=0.001 and p=0.035 respectively) and TBI-based conditioning (p=0.043). In multivariate analysis, severe acute GVHD was the only independent factor associated with TA-TMA (β=3.4, p=0.038).Regarding treatment outcomes, 8 (28%) patients responded to cyclosporine cessation and plasma infusions. The rest 21 out of 29 patients underwent plasma exchange sessions; 14 (48%) of them responded to plasma exchange treatment. One patient that did not respond to plasma exchange received additional Rituximab treatment and the syndrome resolved. The other 6 (20.6%) patients were refractory and eventually succumbed. Treatment-related mortality was 33.3% (9/29) in TA-TMA patients and was directly associated with refractory microangiopathic syndrome in 6/29.Conclusion: Our results suggest that TA-TMA is not rare in unrelated transplant recipients and can be managed in a portion of patients that respond to cyclosporine cessation and plasma exchange. GVHD was the only independent predictor for the development of TA-TMA and therefore, successful prevention and treatment strategies for GVHD need to be timely employed to prevent complications. More importantly, transplanted patients with refractory microangiopathic syndrome showed increased TRM indicating that conventional treatment is inadequate. Recent data of increased complement activation in TA-TMA pave the way for targeted treatment with complement inhibitors in these patients. DisclosuresNo relevant conflicts of interest to declare.

Who Is the Better Donor for Young Hematopoietic Transplant Recipients without Siblings: An Older-Aged Haploidentical Parental Donor or a Young Unrelated Donor?

Introduction:Hematopoietic stem cell transplant (HSCT) outcomes from unrelated donor (URD) and haploidentical donor were very close in recent years, and both could be alternative donors for recipients without siblings. But when considering donor age, especially for young recipients (≤30 years) without siblings, whether outcomes can be improved with a young URD rather than older-aged haploidentical parental donors (HPD) is still unknown.Methods:Between 2008 and 2014, a total of 156 young adult patients with hematological malignancies without sibling donors were assigned to receive URD or HPD HSCT in our center. The strategy of donor selection between URD and HPD was as follows: If an HLA suitably matched URD (≥8 of 10 matching HLA-A, -B, -C, -DRB1, and -DQB1 allele loci and ≥5 of 6 matching HLA-A, -B, and -DRB1 antigen loci) was available, patients were assigned to undergo URD-HSCT. If an HLA suitably matched URD was unavailable, patients were assigned to receive HPD-HSCT. Among them, 10 recipients received HSCT from URDs older than 40 years were further excluded. The transplant procedure had been reported previously (Yi Luo et. al. Blood 2014). Briefly, all patients received myeloablative conditioning involving BuCy without total body irradiation. The GVHD prophylaxis consisted of cyclosporin A, methotrexate, and low-dose mycophenolate mofetil. Grafts were granulocyte-colony stimulating factor mobilized peripheral blood stem cells without ex vivo T-cell depletion.Results:The median age of the finally included 146 young recipients was 21 years (range, 15-30 years). Of whom, 67 received HSCT from HPDs and 79 received HSCT from URDs.The median donor age of the HPDs was 46 years (range, 40-53 years), in contrast to 28 years (range, 20-39 years) of the URDs.EngraftmentAll patients achieved myeloid recovery. The median time and the cumulative 15-day incidences of myeloid engraftment were 12 days (range, 8-16 days) and 97.4% in the URD cohort, and 13 days (range, 8-21 days) and 77.6% in the HPD cohort, respectively. Myeloid recovery in the HPD cohort was significantly delayed compared with URD cohort (P<0.001).Two patients in the HPD cohort experienced primary platelet engraftment failure. The median time and the cumulative 30-day incidences of platelet engraftment were 13 days (range, 6-24 days) and 100% in URDs, and 15 days (range, 6-30 days) and 97.0% in HPDs, respectively. Patients receiving HSCT from HPDs experienced significantly delayed platelet recovery compared with those receiving HSCT from URDs (P<0.001).aGVHDThe incidences of grades II-IV aGVHD were 45.5% in the URD cohort and 47.8% in the HPD cohort (P=0.78), respectively. The incidences of grades III-IV aGVHD were 14.3% in the URD cohort and 17.9% in the HPD cohort (P=0.55), respectively.Long-term OutcomesThere was a trend of higher 5-year overall survival (OS) and relapse free survival (RFS) rates for patients transplanted from young URDs in comparison with HPDs (OS: 64.4% vs 59.6% (P=0.23) and RFS: 63.2% vs 49.6%; (P=0.20)),respectively. The relapse rate and non-relapse mortality (NRM) rate were comparable between two cohorts.For standard risk patients, a significantly higher 5-year OS and RFS rate were observed for patients transplanted from young URDs compared with HPDs (OS: 76.3% vs 52.7% (P=0.03) and RFS: 73.2% vs 53.8%; (P=0.04)), respectively. The significantly lower survival rate in the HPD cohort to some extent could be explained by the higher NRM rate in the HPD cohort (HPD 30.8% vs URD 13.9%, P=0.07). While for high risk patients, long-term outcomes were comparable between two cohorts.Conclusion:These data favor a young URD over an older-aged HPD for young recipients without siblings in standard risk; while for those in high risk, transplant outcomes were comparable between a young URD and an old-aged HPD. Moreover, myeloid and platelet recovery were significantly delayed in HPD-HSCT compared with URD-HSCT. DisclosuresNo relevant conflicts of interest to declare.

HLA-DRB1 allele polymorphism and nasopharyngeal carcinoma risk: a meta-analysis.

The human leukocyte antigens (HLA) DRB1 polymorphism has been implicated in susceptibility to nasopharyngeal carcinoma (NPC). However, the results are inconsistent. The aim of this meta-analysis is to evaluate the association between the HLA-DRB1 polymorphisms and NPC risk. All eligible case-control studies published up to June 17, 2015 were identified by searching PubMed, Web of Science, CNKI, Wanfang, and Weipu databases. The NPC risk associated with the HLA-DRB1 polymorphism was estimated for each study by odds ratios (OR) together with its 95% confidence interval (CI), respectively. Twelve studies with 1152 cases and 1600 controls were included. Overall, a significant positively association between the HLA-DRB1*03, *08, *09, and *10 alleles polymorphism and NPC risk were found (OR=1.55, 95% CI 1.30-1.86; OR=1.44, 95% CI 1.08-1.92; OR=1.33, 95% CI 1.06-1.67; OR=1.82, 95% CI 1.02-3.26, respectively), and the HLA-DRB1*01, *11, and *12 alleles were negatively associated with NPC risk (OR=0.55, 95% CI 0.39-0.78; OR=0.62, 95% CI 0.42-0.91; OR=0.62, 95% CI 0.47-0.81, respectively), but we failed to detect any association between other alleles and NPC risk. When stratified by ethnicity, similar results were observed among Asians for HLA-DRB1*03, *08, *09, *11, and *12 alleles and Tunisians for HLA-DRB1*01, *03, and *11 alleles; However, no significant association among Caucasians was observed. This meta-analysis suggests that the HLA-DRB1*03, *08, *09, and *10 alleles polymorphism contributed to the susceptibility of NPC, whereas HLA-DRB1*11 and *12 alleles polymorphism may be an important protective factor for NPC, especially of Asian populations.

Haploidentical and Matched Sibling Donor Hematopoietic Cell Transplantation for Patients with HLA-Homozygous Haplotypes

More than 1% of the Japanese population has HLA-homozygous haplotypes. For patients with such haplotypes, HLA-haploidentical family members who have no HLA mismatch in the graft-versus-host direction are readily available donor candidates for hematopoietic cell transplantation (HCT). In this study, the outcomes of patients with homozygous HLA-A, -B, and -DRB1 antigens who received HCT without T cell depletion from a haploidentical related donor with mismatches in the host-versus-graft direction only (hetero-to-homo, n = 78) or from an HLA-matched sibling donor (MSD) (MSD-homo, n = 153) were compared with those in patients with heterozygous haplotypes who received HCT from an MSD (MSD-hetero, n = 7242). Transplant outcomes in the hetero-to-homo group were similar to those in the MSD-hetero group regarding neutrophil engraftment, grades III to IV acute graft-versus-host disease (aGVHD), nonrelapse mortality (NRM), relapse, and overall survival. On the other hand, the incidences of severe aGVHD and NRM in the MSD-homo group were significantly lower than those in the MSD-hetero group (grades III to IV aGVHD: aHR .50, P = .034; NRM: aHR .48, P = .004). In conclusion, patients with HLA-homozygous haplotypes achieved lower GVHD and NRM rates for MSD transplantation than those with HLA-heterozygous haplotypes. When an MSD or an appropriate alternative donor is not available for patients with HLA-homozygous haplotypes who need immediate transplantation, transplantation from a haploidentical donor without T cell depletion is a viable option, given the comparable transplant outcomes for hetero-to-homo HCT and MSD-hetero HCT.

Outcomes of Combined Transplants of Cord Blood Plus Peripheral Blood from an HLA Matched Sibling in Thalassemia Patients

▪Background Cord blood from HLA matched sibling was widely used as stem source in transplants in patients with thalassemia major (TM), but failure of engraftment is frequent.Aim To improve engraftment of CB transplant in patients TMPatients and method A combined transplants of CB and peripheral blood (PB) from same HLA matched sibling was conducted (i.e. CB and PB were harvested and infused on day 0) from June, 2010 to February, 2014. Total 24 patients were involved in the study. Donor-recipient pairs were matched at HLA-A, B and DRB1 (antigen level) in 23 but one with HLA mismatched at one loci (DRB1). The conditioning protocol included intravenous busulfan, cyclophosphamide, fludarabine, and thiotepa. Prophylaxis of GVHD included Cyclosporine and short MTX. All donors (newborn) were sent into NICU for monitoring, and then, discharged after 3 days.Results The median age at transplant was 4 years (range, 1.5-7 years), and the ratio of male-to-female patients was 16:8. The median follow-up time was 17 months (range, 5-49 months). The mean mononuclear cell (MNC) dose of CB was 5.67×107/kg body weight of the recipient (BWR; range, 2.1-8.75×107/kg BWR) while that of PB was 3.21×107/kg BWR (range, 0.47-7.31×107/kg BWR). The mean volume of infused CB was 91ml (range, 31-131ml) while that of PB was35ml (range, 10-71ml). The median ANC engraftment time was 28 days (range, 15-47days), while the median platelet engraftment time was 34.0 days (range, 0-128days). The estimated 4-year overall survival (OS) and TM-free survival (TFS) were both 100%. The cumulative incidences of graft rejection and grades II-IV acut egraft-versus-host disease (aGVHD) were both 0%. All donors are normal as peers with following up to date.Conclusion These results suggest that patients with TM have excellent outcomes after CB plus PB combined transplant from an HLA matched sibling. DisclosuresNo relevant conflicts of interest to declare.

Anti-HLA Antibodies Other than Against HLA-A, -B, -DRB1 Adversely Affect Engraftment and Nonrelapse Mortality in HLA-Mismatched Single Cord Blood Transplantation: Possible Implications of Unrecognized Donor-specific Antibodies

The impact of anti-HLA antibodies, except for donor-specific anti-HLA-A, -B, -DRB1 antibodies, on engraftment was retrospectively evaluated in 175 single cord blood transplantations (CBT). Patients and donors had been typed at HLA-A, -B, and -DRB1 antigens, and anti-HLA antibodies had been screened before transplantation to avoid the use of cord blood (CB) units with corresponding antigens. The median age was 59 (range, 17 to 74) years. Overall, 61% were male, 89% had high-risk disease status, 77% received myeloablative conditioning regimens, and over 80% were heavily transfused patients. Sixty-nine of the 175 (39.4%) were positive for anti-HLA antibodies. Thirty-nine patients had antibodies only against HLA-A, -B, or -DRB1, 13 had antibodies only against HLA-C, -DP, -DQ, or -DRB3/4/5, and 17 had antibodies both against HLA-C, -DP, -DQ, or -DRB3/4/5 and against HLA-A, -B, or -DRB1. Because CB units had not been typed at HLA-C, -DP, -DQ, or -DRB3/4/5, it was possible that antibodies against them were unrecognized donor-specific antibodies. Patients with antibodies only against HLA-A, -B, or -DRB1 showed comparable neutrophil engraftment rates to those without antibodies (89.7% versus 83%, P = .65), whereas patients having antibodies against C, DP, DQ, or -DRB3/4/5 showed lower engraftment rate (66.7%, P = .12), which became statistically significant in a subgroup of HLA-mismatched donor-recipient pairs (50%, P = .01). Our results demonstrated that the presence of donor nonspecific anti-HLA-A, -B, -DRB1 antibodies had no significant influence on engraftment, whereas anti-HLA-C, -DP, -DQ, or -DRB3/4/5 antibodies adversely affect engraftment, possibly because of unrecognized donor-specific anti-HLA antibodies against them, especially in HLA-mismatched CBT.

Prospective Evaluation Of Allo-HSCT From Haploidentical-Related Donors Compared With Matched Sibling Donors and Unrelated Donors For Patients With Hematological Malignancies: Results From An Open-Label Trial

▪ IntroductionThe order of alternative donor selection for hematopoietic stem cell transplantation (HSCT) for patients with hematologic malignancies has not been addressed. We performed the first prospective trial to compare the effect of HSCT from matched sibling donors (MSDs), unrelated donors (URDs) and haploidentical- related donors (HRDs) in a contemporary protocol. MethodsFrom 2008 to 2012, 234 patients with hematologic malignancies were enrolled. The treatment schedule was as follows: if a fully MSD was available, patients were assigned treatment with MSD-HSCT. If an MSD was unavailable, a suitably matched URD was used as the alternative, where a suitable match involved matching more than 8 of 10 HLA-A, -B, -C, -DRB1and DQ allele loci ( ¡Ý 8/10) and at least 5 of 6 matching HLA-A, -B, and -DRB1 antigen loci. If only URDs with > 2 mismatching allele loci were available, patients were allowed treatment with HRD-HSCT. Results(1) Sixty-eight patients underwent MSD-HSCT, 98 patients underwent URD-HSCT, and 68 patients underwent HRD-HSCT (Table 1). (2) Grades II¨CIV and severe aGVHD were all significantly more frequent in patients undergoing HRD-HSCT compared with those undergoing MSD-HSCT (II¨CIV: 42.6% vs 19.1%, P = 0.0015; severe aGVHD: 17.65% vs 5.88%, P = 0.03). However, the incidences of II¨CIV and severe aGVHD were comparable in patients receiving transplants from HRDs to those from URDs (II¨CIV: 42.6% vs 40.8%, P = 0.89; severe aGVHD: 17.65% vs 13.27%, P = 0.48). The incidence of cGVHD was not significantly affected by donor types. (3) The 4-year incidence of relapse was not significantly affected by donor types according to all patients (24.2% in the MSD cohort, 22.8% in the URD cohort, 11.9% in the HRD cohort, P > 0.05). However, after controlling for high-risk patients, a superior graft-versus-leukemia (GVL) effect was observed in patients undergoing HRD-HSCT compared to MSD-HSCT or URD-HSCT. In high-risk patients receiving MSD, 36.8% experienced relapse, as did 33.6% in the URD cohort, but the incidence decreased to11.1% in the HRD cohort (MSD vs HRD, P = 0.015; URD vs HRD, P = 0 .028). (4) HRD-HSCT yielded comparable rates of 4-year overall survival (OS) and disease-free survival (DFS) to MSD-HSCT ( OS: 66.4% vs 79.5%, P = 0.071; DFS: 66.4% vs 78.2 %, P = 0.109) or URD-HSCT (OS: 66.4% vs 59%, P = 0.952; DFS: 66.4% vs 58.1%, P = 0.864) (Figure 1).Table 1Patient-, disease-, and transplantation-related characteristicsCharacteristicsMSD HSCT ( n=68 )URD HSCT ( n=98 )HRD HSCT ( n=68 )P valueMSD vs URDMSD vs HRDURD vs HRDAge (median, range), years32.5 (16-56)26 (10-50)25 (9-55)< 0.001< 0.001NSUnderlying disease, n (%)NSNSNSAML29 (42.6)38 (38.8)20 (29.4)ALL24 (35.3)44 (44.9)31(45.6)MPAL02 (2)2 (2.9)CML5 (7.4)2 (2)5 (7.4)MDS6 (8.8)8 (8.2)7 (10.3)NHL4 (5.9)4 (4.1)3 (4.4)Donor-patient gender, n(%)0.002NS0.001Male-male15 (22.1)47 (48)23 (33.8)< 0.001NS0.005Male-female14 (20.6)26 (26.5)13 (19.1)Female-male21 (30.9)11 (11.2)23 (33.8)Female-female18 (26.5)14 (14.3)9 (13.2)Donor-patient blood group, n(%)< 0.001NS0.002Identical45 (66.2)36 (36.7)42 (61.8)Incompatibility23 (33.8)62 (63.3)26 (38.2)Risk classification, n (%)NSNSNSLow risk1 (1.5)2 (2)0 (0)Intermediate/Standard29 (42.6)38(38.8)20 (29.4)High risk38 (55.9)58(59.2)48 (70.6)Time from diagnosis to HSCT, moNSNSNSMedian (range)7.5 (3-126)9 (3-108)8.5 (3-144)Disease status at HSCT, n (%)NSNSNSCR154 (79.4)74 (75.5)47 (69.1)CR28 (11.8)13 (13.3)15 (22.1)¡Ý CR31 (1.5)4 (4.1)0 (0)Advanced stage5(7.4)7(7.1)6 (8.8)Median MNCs, ¡Á108/kg (range)9.96 (0.84-18.66)9.76 (2.37-27.25)10.53 (2.86-16.12)NSNSNSMedian CD34+ count, ¡Á106/kg (range)3.68 (0.715-14.1)5 (0.86-29.64)3.05 (0.8-14.13)0.003NS< 0.001Median follow-up for patients, mo (range)27 (5-54)31 (5-53.5)27 (5.5-52.5)NSNSNS [Display omitted] ConclusionOur data provide convincing clinical evidence to support the use of HRDs, as well as URDs, can be selected as first-line alternative donors, especially for high-risk patients. Disclosures:No relevant conflicts of interest to declare.