Human Leukocyte Antigen Status Research Articles

Improving predictive accuracy in primary biliary cholangitis: Anew genetic risk score.

Genetic variants influence primary biliary cholangitis (PBC) risk. We established and tested an accurate polygenic risk score (PRS) using these variants. Data from two Italian cohorts (OldIT 444 cases, 901 controls; NewIT 255 cases, 579 controls) were analysed. The latest international genome-wide meta-analysis provided effect size estimates. The PRS, together with human leukocyte antigen (HLA) status and sex, was included in an integrated risk model. Starting from 46 non-HLA genes, 22 variants were selected. PBC patients in the OldIT cohort showed a higher risk score than controls: -.014 (interquartile range, IQR, -.023, .005) versus -.022 (IQR -.030, -.013) (p < 2.2 × 10-16). For genetic-based prediction, the area under the curve (AUC) was .72; adding sex increased the AUC to .82. Validation in the NewIT cohort confirmed the model's accuracy (.71 without sex, .81 with sex). Individuals in the top group, representing the highest 25%, had a PBC risk approximately 14 times higher than that of the reference group (lowest 25%; p < 10-6). The combination of sex and a novel PRS accurately discriminated between PBC cases and controls. The model identified a subset of individuals at increased risk of PBC who might benefit from tailored monitoring.

Prospective BASECAMP-1 experience in patients with gastrointestinal (GI) cancer: Identifying patients with human leukocyte antigen (HLA) loss of heterozygosity (LOH) for a future therapeutic trial exploiting LOH as a tumor vulnerability.

209 Background: Metastatic colorectal (CRC), pancreatic (PANC), and gastroesophageal cancers are the leading causes of GI cancer–related mortality (5-y survival: 15%, 3%, and 5%-6%, respectively) (ACS 2022). HLA LOH is a recurrent mechanism of immune escape observed in 15%-20% of GI cancers (Hecht R., ASCO GI 2022). The Tmod platform is a logic-gated chimeric antigen receptor (CAR) T-cell modular system, comprising a carcinoembryonic antigen (CEA)- or mesothelin (MSLN)-targeting CAR activator and a separate HLA-A*02-targeting blocker receptor. Both in vitro/in vivo, Tmod CAR T therapy kills cells with HLA-A*02 LOH (tumor) without harming cells with retained HLA-A*02 expression (normal). However, HLA-A*02 LOH can only be therapeutically exploited if patients are identifiable through a feasible and timely clinical workflow. Methods: We established a biobanking protocol (BASECAMP-1, NCT04981119) to determine whether HLA-A*02 LOH patients can be prospectively identified. Patients with CRC, PANC, or non-small cell lung cancer (NSCLC), and a high risk for incurable relapse, were screened first using a standard HLA assay. Heterozygous HLA-A*02 positive tumor samples were then assessed for LOH using a bioinformatic algorithm applied via the Tempus xT platform. Results: As of Sep 1, 2022, 83 patients were consented at 4 institutions. HLA status was obtained from 70 patients and 28 were identified as HLA-A*02:01 heterozygous (40%; expected frequency based on USA NMDP data, 27.6%). LOH results were available for 16 patients; 4 LOH-positive patients were identified (25%, 2 PANC, 2 NSCLC). The LOH assay sensitivity declines below a tumor purity of 40% (Hecht R., ASCO GI 2022). Six patients had a tumor purity of 20% (all with PANC, a tumor known for high stromal content), limiting possible LOH detection. The impact of tumor purity on LOH sensitivity was highlighted in a patient with a low initial sample tumor purity (30%) that resulted in a 41% probability of HLA-A*02:01 LOH (below positive threshold). A second sample with a higher tumor purity (70%), obtained from formalin-fixed, paraffin-embedded sections, resulted in a 92% probability of HLA-A*02:01 LOH (positive). Conclusions: BASECAMP-1 prospective identification of HLA-A*02 LOH is feasible in the real-world setting. The frequencies of the HLA-A*02 allele and of HLA-A*02 LOH in this cohort mirrored expected population frequencies. LOH results can be obtained within a clinically feasible workflow and timeframe, although samples with a &lt; 40% tumor purity have a reduced sensitivity for LOH detection, an issue recurrently observed in patients with PANC. The BASECAMP-1 strategy enables prospective identification of appropriate patients for future therapeutic clinical trials using Tmod CEA and MSLN logic-gated CAR T cells. Clinical trial information: NCT04981119 .

Systematic analysis the genomic and microenvironment characteristics with the status of human leukocyte antigen (HLA) and the integration of HLA LOH, TMB and PD-L1 could further distinguish the responders to immunotherapy.

e20529 Background: Although studies have shown that loss of heterozygosity (LOH) at the human leukocyte antigen (HLA) locus is one of the mechanisms of immune escape, the effect of HLA LOH on the immune checkpoint inhibitors (ICIs) treatment is still need to be further investigated, especially for the patients with positive programmed cell death-Ligand 1 (PD-L1) expression and high tumor mutation burden (TMB). Methods: 425 sample of Chinese lung cancer patients who received PD-L1 immunotherapy were performed with targeted panel sequencing to analyzed the genomic characteristics with HLA status. 994 non-small cell lung cancer (NSCLC) sample from The Cancer Genome Atlas (TCGA) were used to analyze the impact of HLA LOH on the tumor microenvironment. In addition, 89 samples from previous study were used to analyze the association of HLA status with the ICIs treatment in NSCLC. Results: The genomic characteristics from 425 sample of Chinese lung cancer patients who received PD-L1 immunotherapy were analyzed. We found that mutation frequency of driver genes and TMB in the HLA LOH high group were significantly increased. Transcriptome analysis revealed HLA LOH played a critical role in the tumor immune microenvironment in PD-L1+/TMB-H population and the impact on lung adenocarcinoma was greater than that on lung squamous cell carcinoma. Progression-free survival of PD-L1+/TMB-H population was significantly decreased in HLA LOH group which suggest that comprehensive considering HLA LOH as a biomarker may improve clinical response to immunotherapy. Conclusions: This work showed the genomic and immune microenvironment characteristics of HLA LOH and demonstrated HLA LOH as a significant negative predictor of outcomes after ICIs treatment, especially in PD-L1+/TMB-H population. These data suggested that comprehensive considering HLA LOH as a biomarker may improve clinical response to immunotherapy.

Hashimoto's thyroiditis and coexisting disorders in correlation with HLA status-an overview.

Hashimoto's thyroiditis (HT), also known as chronic lymphocytic thyroiditis, is afrequent disorder of the thyroid gland caused by autoimmune-trigged lymphocytic infiltration and destruction of the thyroid gland. With the progressive destruction of the organ, the thyroid gland shrinks in size, thus commonly leading to hypothyroidism. Therapy of HT is mainly focused on managing the thyroid dysfunction by oral substitution of L‑thyroxine. However, patients with HT often complain about abroad spectrum of symptoms, with some of them hardly explained by HT itself. Several other disorders are known to be associated with HT. The etiology of HT seems to be multifactorial, including environmental influences such as iodine supply, infections, and stress as triggers of immune modulation. In addition, also agenetic background based on changes of the human leukocyte antigen (HLA) status seems to be evident. The paper will provide an overview of diseases related to HT, including their correlation to certain HLA patterns. This presentation should give abroader view on HT-related disorders and facilitate detailed examination and management of patients with HT.

Narcolepsy Type 1: A Remitting Disease? An Unusual Case Report

We describe the case of a male patient who was diagnosed with narcolepsy type 1 on the basis of sleep and wake symptoms, and the results of investigations including video-polysomnography, multiple sleep latency test, human leukocyte antigen status and orexin level in cerebrospinal fluid. During the first years after disease onset, the patient did not show any significant improvement despite treatment with a variety of stimulant and anti-cataplectic drugs. However, spontaneous remission of disease occurred after 15 years.

The Unfavorable Impact of DR9/DR9 Genotype on the Frequency and Quality of Partial Remission in Type 1 Diabetes.

Partial remission (PR) is a specific stage in type 1 diabetes (T1D). Although human leukocyte antigen (HLA) class II loci are the strongest genetic determinants in T1D, the relationship between PR and HLA remains unclear. To investigate the association between PR status and HLA genotypes in patients with T1D. A total of 237 patients with T1D were included. PR was defined according to C-peptide ≥300 pmol/L. The frequency of PR and peak C-peptide levels during remission phase were compared according to HLA status. Clinical characteristics including age of onset and diabetes autoantibodies were collected. All analyses were duplicated when subjects were divided into childhood- and adult-onset T1D. The median follow-up time was 24 months, 65.8% (156/237) of patients with T1D went into PR. DR9/DR9 carriers had a lower PR rate (44.2% vs 70.6%, P = .001) and were less likely to enter PR (OR = 0.218, 95% CI 0.098-0.487, P < .001) than the non-DR9/DR9 carriers, observed in both childhood- and adult-onset T1D. Besides, the peak C-peptide level during PR phase was also lower in DR9/DR9 carriers, and more notable in adult-onset T1D. When compared with non-DR9/DR9 carriers, T1D with DR9/DR9 genotype presented an older age of onset and a lower positivity of zinc transporter 8 antibody (ZnT8A), and the lower trend of ZnT8A was only found in adult-onset T1D (P = .049). Patients with T1D carrying susceptible DR9/DR9 are less prone to undergo PR. Additionally, the recovery extent of β-cell function during the PR phase tends to be lower in adults carrying DR9/DR9, which might be associated with ZnT8A.

IL-15 Gene Polymorphism in Celiac Disease Patients and Their Siblings.

Celiac disease (CD) is an immune-mediated enteropathy characterized by lifelong gluten intolerance. Interleukin-15 (IL- 15) is a proinflammatory cytokine that is considered a key component in the immune reaction triggered by gluten. Our aim of this study was to evaluate the influence of IL-15 gene polymorphisms on CD development and clinical presentation. The study was enrolled-with 90 CD patients (49 female/41 male, median years of age 11), their 38 siblings (20 female/18 male, median years of age 8), and 99 healthy controls (66 female/33 male, median years of age 13). Their demographic findings, symptoms, and signs histopathological grade, Human Leukocyte Antigen (HLA) types were recorded. IL-15 gene polymorphisms rs2857261, rs10519613, and rs1057972 were analyzed through PCR. There was a significantly higher frequency of GG genotype in rs2857972 polymorphisms and TT genotype in rs1057972 polymorphisms in celiac families compared to controls [41% vs. 23% (P = .0008), 36% vs. 11% (P = .001), respectively]. Without considering their HLA status, there was not any difference between celiacs and healthy siblings. However, when stratified according to their HLADQ2 status, rs2857972 GG polymorphism was 1.5 times prominent in celiacs than siblings at homozygous state, whereas rs1057972 TT genotype was found to be 2.5 times prominent in celiac siblings at heterozygous state. There was no association between these polymorphisms and clinical presentation. rs2857972 GG and rs1057972 TT variants of IL 15 are more prominent in celiac families than controls. However, the impact of IL-15 gene polymorphism on CD development is dependent on HLADQ2 status.

Changes in the proportion of clinical clusters contribute to the phenotypic evolution of Beh\xe7et\u2019s disease in Japan

BackgroundWe hypothesized that Behçet’s disease (BD) consists of several clinical subtypes with different severity, resulting in heterogeneity of the disease. Here, we conducted a study to identify clinical clusters of BD.MethodsA total of 657 patients registered in the Yokohama City University (YCU) regional BD registry between 1990 and 2018, as well as 6754 patients who were initially registered in the Japanese Ministry of Health, Labour and Welfare (MHLW) database between 2003 and 2014, were investigated. The YCU registry data regarding the clinical manifestations of BD, human leukocyte antigen (HLA) status, treatments, and hospitalizations were analyzed first, followed by similar analyses of the MHLW for validation. A hierarchical cluster analysis was independently performed in both patient groups.ResultsA hierarchical cluster analysis determined five independent clinical clusters in the YCU cohort. Individual counterparts of the YCU clusters were confirmed in the MHLW registry. Recent phenotypical evolutions of BD in Japan, such as increased gastrointestinal (GI) involvement, reduced complete type according to the Japan Criteria, and reduced HLA-B51 positivity were associated with chronologically changing proportions of the clinical clusters.ConclusionsIn this study, we identified independent clinical clusters among BD patients in Japan and found that the proportion of each cluster varied over time. We propose five independent clusters namely “mucocutaneous”, “mucocutaneous with arthritis”, “neuro”, “GI”, and “eye.”

Abstract 6684: Association of human leukocyte antigen (HLA) homozygosity with unfavorable clinical outcomes in patients with non-small cell lung cancer (NSCLC) treated with PD-L1 inhibitors as frontline therapy

Abstract Background: High polymorphic diversity in HLA class I (HLA-I) is essential for successful immunologic control of cancer. Lung cancer patients with maximal HLA-I heterozygosity treated with single-agent PD-L1 inhibitors as their second-line or beyond were reported with longer overall survival. However, the role of HLA heterozygosity for patients with NSCLC who received single-agent immunotherapy with or without chemotherapy as their first-line has not been reported. Methods: Patients with unresectable stage III or IV NSCLC who underwent next-generation sequencing with HLA typing were enrolled in our study (N=27). HLA genotypes were determined using DNA sequencing data. They received either pembrolizumab (N=5) or pembrolizumab plus chemotherapy (N=22) as their first-line treatment. Kaplan-Meier curves were constructed to compare survival outcomes according to HLA (homozygous vs. heterozygous) and tumor mutation burden (TMB, above vs. below median) status. A log-rank test was applied to compare Kaplan-Meier curves between groups. Hazard ratios were derived from the Cox-proportional hazards model with adjustment for baseline characteristics including age, sex, and TMB. Results: We determined HLA-I genotypes consisting of two alleles in 27 patients with NSCLC. Among these enrollees, 23 patients (85.2%) were heterozygous at every HLA-I locus and four patients (14.8%) were homozygous at more than one HLA-I locus. Response Evaluation Criteria in Solid Tumors (RECIST) evaluable patients were 19. In the HLA-heterozygous group (N=15), three patients (20%) had partial response (PR), eight patients (53.3%) had stable disease, and four patients (26.7%) had progressive disease (PD), whereas in the HLA-homozygous group (N=4), one (25%) had PR, one (25%) had SD, and two (50%) had PD. The disease control rates (CR, PR, and SD) were 73.3% in the HLA-heterozygous group and 50% in the HLA-homozygous group. Homozygosity at HLA-I genes seemed to be associated with shorter progression-free survival (PFS, HR=3.2, 95% CI=0.71-15, p=0.13) compared with heterozygosity at HLA-I genes. The HLA-heterozygous group had longer median PFS than the HLA-homozygous group (19 vs. 9.5 months, Log-rank p=0.11). When we controlled the effect of HLA homozygosity on PFS for age, sex, and TMB, the adjusted HRs were 4.4[0.82-23], 3.1[0.69-14] and 1.9[0.36-9.8] respectively. Conclusion: No data exists on the effect of HLA homozygosity on clinical outcomes of patients treated with immunotherapy with or without chemotherapy as frontline treatment. We for the first time report that in such setting HLA homozygosity may be associated with worse outcomes. Citation Format: Dongyup Lee, Jonghanne Park, Horyun Choi, Gahyun Gim, Sukjoo Cho, Leeseul Kim, Cyra Y. Kang, Pedro Viveiros, Young Kwang Chae. Association of human leukocyte antigen (HLA) homozygosity with unfavorable clinical outcomes in patients with non-small cell lung cancer (NSCLC) treated with PD-L1 inhibitors as frontline therapy [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 6684.

Targeting proinsulin to local immune cells using an intradermal microneedle delivery system; a potential antigen-specific immunotherapy for type 1 diabetes

Antigen-specific immunotherapy (ASI) has been proposed as an alternative treatment strategy for type 1 diabetes (T1D). ASI aims to induce a regulatory, rather than stimulatory, immune response in order to reduce, or prevent, autoimmune mediated β-cell destruction, thus preserving endogenous insulin production. The abundance of immunocompetent antigen presenting cells (APCs) within the skin makes this organ an attractive target for immunotherapies. Microneedles (MNs) have been proposed as a suitable drug delivery system to facilitate intradermal delivery of autoantigens in a minimally invasive manner. However, studies to date have employed single peptide autoantigens, which would restrict ASI to patients expressing specific Human Leukocyte Antigen (HLA) molecules, thus stratifying the patient population. This study aims to develop, for the first time, an intradermal MN delivery system to target proinsulin, a large multi-epitope protein capable of inducing tolerance in a heterogeneous (in terms of HLA status) population of T1D patients, to the immunocompetent cells of the skin. An optimized three component coating formulation containing proinsulin, a diluent and a surfactant, facilitated uniform and reproducible coating of >30 μg of the active pharmaceutical ingredient on a stainless steel MN array consisting of thirty 500 μm projections. When applied to a murine model these proinsulin-coated MNs efficiently punctured the skin and after a limited insertion time (150 s) a significant proportion of the therapeutic payload (86%) was reproducibly delivered into the local tissue. Localized delivery of proinsulin in non-obese diabetic (NOD) mice using the coated MN system stimulated significantly greater proliferation of adoptively transferred antigen-specific CD8+ T cells in the skin draining lymph nodes compared to a conventional intradermal injection. This provides evidence of targeted delivery of the multi-epitope proinsulin antigen to skin-resident APCs, in vivo, in a form that enables antigen presentation to antigen-specific T cells in the local lymph nodes. The development of an innovative coated MN system for highly targeted and reproducible delivery of proinsulin to local immune cells warrants further evaluation to determine translation to a tolerogenic clinical outcome.

Human Leukocyte Antigen and its Association with Celiac Disease and Associated Autoimmune Diseases

Introduction: Human Leukocyte Antigen (HLA) is a crucial component for the regulation of human immune systems. Celiac disease (CeD) is a gluten dependent multifactorial disorder with a strong association with HLA-DQ alleles. HLA-DQ alleles are also have role in Non-Celiac Gluten Sensitivity (NCGS), Dermatitis herpetiformis (DH), and CeD associated autoimmune diseases like Type 1 diabetes (T1D), Rheumatoid arthritis (RA), Multiple sclerosis (MS). However, contribution of HLA in all these diseases is not fully understood. We aimed to provide a concise information about the HLA status in these autoimmune diseases. Methodology: We explored already published articles having information about HLA in autoimmune diseases in relation to CeD from different scientific platforms. We filtered the HLA data from them. We included original and review articles and excluded articles which had only clinical information, and case reports. Results: We found that HLA alleles have strong association in the development of CeD and other autoimmune diseases. HLA-B1*02 is the most critical allele associated with the susceptibility to CeD and also have major role in other gluten related disorders (GRD). Conclusions: We concluded that although HLA has a major role in the autoimmune disease development, multiple unknown non-HLA genes are also critically involved and must be explored frantically.

Multimodal genomic features predict outcome of immune checkpoint blockade in non-small-cell lung cancer.

Despite progress in immunotherapy, identifying patients that respond has remained a challenge. Through analysis of whole-exome and targeted sequence data from 5,449 tumors, we found a significant correlation between tumor mutation burden (TMB) and tumor purity, suggesting that low tumor purity tumors are likely to have inaccurate TMB estimates. We developed a new method to estimate a corrected TMB (cTMB) that was adjusted for tumor purity and more accurately predicted outcome to immune checkpoint blockade (ICB). To identify improved predictive markers together with cTMB, we performed whole-exome sequencing for 104 lung tumors treated with ICB. Through comprehensive analyses of sequence and structural alterations, we discovered a significant enrichment in activating mutations in receptor tyrosine kinase (RTK) genes in nonresponding tumors in three immunotherapy treated cohorts. An integrated multivariable model incorporating cTMB, RTK mutations, smoking-related mutational signature and human leukocyte antigen status provided an improved predictor of response to immunotherapy that was independently validated.

An Improved Patient-Derived Xenograft Humanized Mouse Model for Evaluation of Lung Cancer Immune Responses.

Human tumor xenograft models do not replicate the human immune system and tumor microenvironment. We developed an improved humanized mouse model, derived from fresh cord blood CD34+ stem cells (CD34+ HSC), and combined it with lung cancer cell line-derived human xenografts or patient-derived xenografts (Hu-PDX). Fresh CD34+ HSCs could reconstitute detectable mature human leukocytes (hCD45+) in mice at four weeks without the onset of graft-versus-host disease (GVHD). Repopulated human T cells, B cells, natural killer (NK) cells, dendritic cells (DC), and myeloid-derived suppressor cells (MDSC) increased in peripheral blood, spleen, and bone marrow over time. Although cultured CD34+ HSCs labeled with luciferase could be detected in mice, the cultured HSCs did not develop into mature human immune cells by four weeks, unlike fresh CD34+ HSCs. Ex vivo, reconstituted T cells, obtained from the tumor-bearing humanized mice, secreted IFNγ upon treatment with phorbol myristate acetate (PMA) or exposure to human A549 lung tumor cells and mediated antigen-specific CTL responses, indicating functional activity. Growth of engrafted PDXs and tumor xenografts was not dependent on the human leukocyte antigen status of the donor. Treatment with the anti-PD-1 checkpoint inhibitors pembrolizumab or nivolumab inhibited tumor growth in humanized mice significantly, and correlated with an increased number of CTLs and decreased MDSCs, regardless of the donor HLA type. In conclusion, fresh CD34+HSCs are more effective than their expanded counterparts in humanizing mice, and do so in a shorter time. The Hu-PDX model provides an improved platform for evaluation of immunotherapy.

Prognosis for residual islet β-cell secretion function in young patients with newly diagnosed type 1 diabetes.

This study investigated possible predictors of residual islet β-cell function (RBF) in young patients with newly diagnosed type 1 diabetes (T1D). After analyzing RBF in 443 patients with T1D according to age at diagnosis and disease duration, 110 were followed-up over 18-60 months. A nomogram was developed by logistic regression to explore factors associated with long-term RBF. Of the 443 T1D patients (mean [±SD] age 20.28 ± 5.50 years; mean [±SD] diabetes duration 28.5 ± 14.6 months), RBF was preserved in 64.3%. Independent predictors for poor RBF outcome among the 110 patients in the follow-up cohort were age at onset (odds ratio [OR] 0.82; 95% confidence interval [CI] 0.73-0.92; P < 0.001), high-risk human leukocyte antigen (HLA) status (OR 4.73; CI 1.28-17.52; P = 0.020), female sex (OR 3.39; CI 1.03-11.22; P = 0.045), and a history of diabetic ketoacidosis (DKA; OR 8.71; CI 2.31-32.83; P < 0.001). Baseline glutamic acid decarboxylase (GAD) antibody, family history of diabetes, body mass index, insulin dosage, and C-peptide and HbA1c levels were not associated with poor RBF outcome. Intensive glycemic control after T1D diagnosis may improve RBF within a mean (±SD) follow-up of 35.1 ± 13.8 months. The calibration plot for the probability of 2-, 3-, and 4-year RBF showed optimal agreement between nomogram-predicted and actual observed probabilities. Younger age of onset, female sex, higher HLA risk status, and a history of DKA were the main factors predicting long-term poor preserved β-cell function. Glycemic control could improve RBF during the course of diabetes. The nomogram provides an individualized risk estimate of RBF in patients with newly diagnosed T1D within Chinese Han populations.

Association of Ménière disease with human leukocyte antigen in Taiwanese population.

The etiology of Ménière disease (MD) is multifactorial; genetic factors seem to play an important role. The associations between MD and human leukocyte antigen (HLA) status have been studied previously in several populations and have shown that the HLA alleles imparting susceptibility varied. In the present study, we explored HLA status in Taiwanese patients with definitive MD. HLA was typed via polymerase chain reaction, sequence-specific oligonucleotide genotyping in 35 patients with MD diagnosed using the criteria of the American Academy of Otolaryngology-Head and Neck Surgery and 70 unrelated healthy controls. HLA allele association tests were used to evaluate differences in allelic frequencies between the patients and controls. The allelic frequency of HLA-A*11 was significantly greater in MD patients than in controls (52.9 vs. 31.4%, odds ratio: 2.45, 95% confidence interval: 1.4 to 4.4, p = 0.004, p corrected = 0.03). Thus, A*11 may be a useful HLA biomarker in Taiwanese patients with MD. Further larger-scale studies are required.

Anti-Thyroid Peroxidase Reactivity Is Heightened in Pemphigus Vulgaris and Is Driven by Human Leukocyte Antigen Status and the Absence of Desmoglein Reactivity.

Pemphigus vulgaris (PV) belongs to an autoimmune disease cluster that includes autoimmune thyroid disease (AITD), suggesting common mechanisms driving autoimmune susceptibility. Our group has shown that PV patients exhibit significant reactivity to AITD-related anti-thyroid peroxidase (anti-TPO), and anti-TPO antibodies affect signaling pathways in keratinocytes similar to anti-desmoglein (Dsg) 3 antibodies. To further assess the relevance of anti-TPO reactivity in PV, we analyzed anti-TPO levels in 280 PV and 167 healthy control serum samples across a comprehensive set of variable and static parameters of disease activity and etiopathogenesis. PV patients have significantly higher activity rates (A.R.s) for anti-TPO than healthy controls, but levels do not differ between phases of clinical activity and remission. Patients that carry both the PV-associated human leukocyte antigen (HLA) alleles DRB1*0402 and DQB1*0503, or DQB1*0503 alone show a low prevalence of anti-TPO (A.R. 9.5 and 4.8%, respectively), while patients that lack expression of these alleles or carry DRB1*0402 alone have a much higher prevalence of anti-TPO (A.R. 23.1 and 15.8%, respectively), suggesting that the absence of DQB1*0503 may predispose patients to the development of anti-TPO antibodies. Similarly, anti-Dsg1−/3− patients have a higher anti-TPO A.R. (26.9%) than anti-Dsg1−/3+ (18.8%), anti-Dsg1+/3− (14.3%), and anti-Dsg1+/3+ (3.9%) patients. Our data suggest that anti-TPO reactivity in PV is driven by genetic markers that may be in linkage disequilibrium with the established PV-susceptibility alleles and that this association drives the selection of a combination of anti-Dsg and anti-TPO antibodies, with anti-TPO filling the gap in active patients that do not carry the established PV-associated autoantibodies and/or are lacking the established PV-HLA-susceptibility alleles.

Characterization of ankylosing spondylitis in Upper Egypt

Objective: To explore the features of ankylosing spondylitis (AS) in Upper Egypt which has been under estimated in this area known for its lower socioeconomic status (SES). Methods: Seventy patients with a definite diagnosis of AS were prospectively evaluated. Information about human leukocyte antigen (HLA-B27) status, pattern of axial and peripheral involvement, inflammatory markers, extra axial features and axial radiographic findings together with other demographic variables were recorded. Bath AS disease activity and functional status (BASDAI and BASFI) were also assessed. Results: The mean age at onset was 24.9 ± 7.5 years and at diagnosis was 35.46 ± 12.1 years, with a diagnostic delay of 9.9 years on average. The male to female ratio was 2.9:1. HLA-B27 was positive in 38 of 51 patients (74.5%). Eighteen patients (25.7%) had a family history of AS. Peripheral arthritis was present in 14 patients (20%). Anterior uveitis was present in 5 patients (7.1%). The mean radiographic sacroiliitis grade was 2.42 ± 0.59. Lumbar syndesmophytes were present in 45 patients (64.3%) and bamboo spine was present in 13 (18.6%). Thirty (42.9%) patients had radiographic hip abnormalities, of whom 6 had received hip replacement surgery. Of 65 patients examined by bone densitometry, osteoporosis was diagnosed in 26 patients (40%). The mean BASDIA and BASFI were 4.8 ± 1.18 and 5.4 ± 1.5, respectively. Axial radiographic damage was significantly greater in men (P >0.001). Only 6 patients (8.6%) were aware of the nature of the disease and were maintained on regular treatment. Conclusion: The characteristics of AS in Upper Egypt were revealed. Noticeable radiographic damage with a high BASFI and BASDAI indicated a more severe disease than that reported in other Middle Eastern populations with a higher SES.

Routine C4d immunohistochemistry in cardiac allografts: Long-term outcomes

In the past decade, C4d has emerged as a potential marker for antibody-mediated rejection (AMR); however, evidence on its use as a prognostic tool has been controversial. Although the International Society for Heart and Lung Transplantation guideline recommends early routine surveillance of C4d in heart transplantation, there is no consensus on its value in the pathologic assessment of AMR. Herein we present a correlation analysis of C4d immunoreactivity in endomyocardial biopsies with clinical cardiac dysfunction, cellular rejection, human leukocyte antigen (HLA) status, cardiac allograft vasculopathy (CAV) and death. A total of 5,840 endomyocardial biopsies from 296 heart transplant recipients (January 2004 to December 2014) were stained prospectively for C4d. Strong, diffuse endothelial staining was considered positive. All patients had at least 1 year of follow-up. Positive C4d staining was present in 53 biopsies from 28 patients. Sixteen of 28 patients had clinically significant cardiac dysfunction at the time of positive biopsy. In C4d-positive patients, the mean panel-reactive antibody (PRA) level was 33%. Ten patients demonstrated a first C4d positivity within the first year post-transplant, whereas 18 patients had C4d positivity after 1 year post-transplant. At autopsy, all 11 C4d-positive patients examined demonstrated cardiac allograft vasculopathy (CAV) as the underlying cause of death. In contrast, only 2 of 8 (25%) C4d-negative patients had CAV at autopsy. In the surviving cohort, there was an angiographic diagnosis of higher-than-moderate CAV in 10 patients (3.8%). C4d-positive patients contributed to 67% of the overall institutional mortality in heart transplant recipients. Late C4d positivity (>1 year post-transplant) demonstrated an even higher risk for developing CAV and poor prognosis than early C4d positivity (within 1 year). In the C4d-negative group with postmortem examination, 75% (6 of 8) deaths were due to non-cardiac causes. Our findings show a positive association of C4d with CAV and death. We identified a prognostic role for C4d in heart transplantation warranting routine long-term detection of this marker in the pathologic evaluation of cardiac AMR.

Factors Determining the Outcome of Hematopoietic Stem Cell Transplantation in Patients With Acute Lymphoblastic Leukemia at King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.

Medical records of 82 patients with acute lymphoblastic leukemia (ALL) who underwent hematopoietic cell transplantation (HCT) at our institution from 2005 to 2011 were reviewed. Forty-five patients were male (54.8%). The median age at HCT was 7.46 years (range, 0.98 to 14.31 y), the median time to HCT after diagnosis was 12.56 months. Ten patients were below the age of 1 year (12%). All patients were in complete remission at the time of HCT. In 83 transplants, 64 patients received HCT from human leukocyte antigen-identical-related donors and 19 from other donors. Stem cell source was bone marrow in 65 (78%) and cord blood in 18 (22%). Five-year overall survival was 58.8% and event-free survival was 54.3%. The cumulative incidence of acute graft versus host disease was 4.8%±2.3% and of chronic graft versus host disease was 8.9%±3.2%. The median time to absolute neutrophil count and platelet recovery was 17 days (range, 12 to 43 d) and 28 days (range, 15 to 98 d), respectively. One patient acquired CMV infection after transplant. No one developed venoocclusive disease, hemorrhagic cystitis, or other complication. Patient's age at diagnosis, sex, donor's human leukocyte antigen status and sex, source of transplant and complete remission status at HCT did not affect overall survival and event-free survival. Our results show a favorable outcome to HCT for acute lymphoblastic leukemia patients comparable to published data, and no single factor was associated with superior outcome.

Analysis of nucleophosmin-anaplastic lymphoma kinase (NPM-ALK)-reactive CD8(+) T cell responses in children with NPM-ALK(+) anaplastic large cell lymphoma.

Cellular immune responses against the oncoantigen anaplastic lymphoma kinase (ALK) in patients with ALK-positive anaplastic large cell lymphoma (ALCL) have been detected using peptide-based approaches in individuals preselected for human leucocyte antigen (HLA)-A*02:01. In this study, we aimed to evaluate nucleophosmin (NPM)-ALK-specific CD8(+) T cell responses in ALCL patients ensuring endogenous peptide processing of ALK antigens and avoiding HLA preselection. We also examined the HLA class I restriction of ALK-specific CD8(+) T cells. Autologous dendritic cells (DCs) transfected with in-vitro-transcribed RNA (IVT-RNA) encoding NPM-ALK were used as antigen-presenting cells for T cell stimulation. Responder T lymphocytes were tested in interferon-gamma enzyme-linked immunospot (ELISPOT) assays with NPM-ALK-transfected autologous DCs as well as CV-1 in Origin with SV40 genes (COS-7) cells co-transfected with genes encoding the patients' HLA class I alleles and with NPM-ALK encoding cDNA to verify responses and define the HLA restrictions of specific T cell responses. NPM-ALK-specific CD8(+) T cell responses were detected in three of five ALK-positive ALCL patients tested between 1 and 13 years after diagnosis. The three patients had also maintained anti-ALK antibody responses. No reactivity was detected in samples from five healthy donors. The NPM-ALK-specific CD8(+) T cell responses were restricted by HLA-C-alleles (C*06:02 and C*12:02) in all three cases. This approach allowed for the detection of NPM-ALK-reactive T cells, irrespective of the individual HLA status, up to 9 years after ALCL diagnosis.