UNASSIGNED: HLA-B*58:01 is a well-known risk factor for allopurinol-induced severe cutaneous adverse reactions (SCARs). However, only a minority of HLA-B*58:01 carriers suffer SCARs after taking allopurinol. The aim of this study was to investigate subsidiary genetic markers that could identify those at further increased risk of developing allopurinol-induced drug reaction with eosinophilia and systemic symptoms (DRESS) in subjects with HLA-B*58:01.
UNASSIGNED: Subjects with B*58:01 were enrolled (21 allopurinol-induced DRESS and 52 allopurinol-tolerant control). HLA-A, -B, -C and -DRB1 alleles were compared. Comparison of risk between HLAs and allopurinol-induced SCAR in separate populations was performed to support the results. Kruskal-Wallis test, Pearson\'s chi-square test, Fisher\'s exact test and binary logistic regression were used to analyze the risk of SCAR development.
UNASSIGNED: Frequencies of A*24:02 (71.4 vs. 17.3%, p < 0.001, odds ratio [OR] = 12.0; 95% confidence interval [CI], 3.6-39.2) were significantly higher in B*58:01 (+) DRESS than B*58:01 (+) tolerant controls. In addition, DRB1*13:02 further increased the risk of DRESS. The phenotype frequency of A*24:02/DRB1*13:02 was significantly higher in the B*58:01 (+) DRESS group than in the B*58:01 (+) tolerant controls (52.4% vs. 5.8%, p < 0.001, OR, 66.0; 95% CI, 6.1-716.2). In 2782 allopurinol user cohort, the overall prevalence of DRESS was 0.22%, which increased to 1.62% and 2.86% in the presence of B*58:01 and B*58:01/A*24:02, respectively.
UNASSIGNED: The additional secondary screening with A*24:02 and DRB1*13:02 alleles may identify those at further increased risk of allopurinol-induced DRESS in B*58:01 carriers.

遗传性血色病是一种铁代谢障碍性疾病，较为罕见。现报道1例转铁蛋白受体（TFR）2基因突变相关血色病患者，临床表现为皮肤色素沉着、糖尿病、肝硬化，血清铁蛋白（8 548.9 ng/ml）、转铁蛋白饱和度（116.77%）明显升高，肝活检示肝硬化，肝内铁沉积（重度Ⅳ级），对其血液标本进行全外显子捕获和高通量测序，并经Sanger测序验证，发现在TFR2基因10号和7号外显子上检测到2个杂合突变（c.1288G＞A，p.G430R和c.960T＞A，p.Y320X），前者已有文献报道与血色病的发病密切相关；后者罕见报道，是TFR2基因新变异点，该突变可使肽链终止。.

Mismatched human leukocyte antigen (HLA) loss is an essential mechanism involved in immune escape and recurrence in acute leukemia after haploidentical transplantation. Patients relapsing after transplantation with HLA loss have a poor prognosis, and are less likely to benefit from donor lymphocyte infusion (DLI) from the original donor. Here, we report a patient with high-risk acute myeloid leukemia who relapsed within six months after haploidentical peripheral blood stem cell transplantation (PBSCT) combined with unrelated umbilical cord blood (UCB) with a session of prophylactic DLI. This patient achieved transient remission after subsequent Interferon-α-1b treatment for two weeks but experienced a second relapse within one month. Genomic analysis by real-time PCR assay revealed that this patient had a loss of an entire mismatched HLA haplotype that was derived from her haploidentical donor. Haploidentical peripheral blood stem cell transplantation with prophylactic DLI might be a triggering event for HLA loss relapse after haploidentical transplantation combined with UCB. HLA loss should be considered in patients with post-HSCT relapse, especially in haploidentical transplantation.

Atopic dermatitis (AD) is a common immune-medicated skin disease. Previous studies have explored the relationship between Human Leukocyte Antigen (HLA) allelic variation and AD with conflicting results. The aim was to examine HLA Class I genetic variation, specifically peptide binding groove variation, and associations with AD. A case-control study was designed to evaluate HLA class I allelic variation and binding pocket polymorphisms, using next generation sequencing on 464 subjects with AD and 388 without AD. Logistic regression was used to evaluate associations with AD by estimating odds ratios (95% confidence intervals). Significant associations were noted with susceptibility to AD (B*53:01) and protection from AD (A*01:01, A*02:01, B*07:02 and C*07:02). Evaluation of polymorphic residues in Class I binding pockets revealed six amino acid residues conferring protection against AD: A9F (HLA-A, position 9, phenylalanine) [pocket B/C], A97I [pocket C/E], A152V [pocket E], A156R [pocket D/E], B163E [pocket A] and C116S [pocket F]. These findings demonstrate that specific HLA class I components are associated with susceptibility or protection from AD. Individual amino acid residues are relevant to protection from AD and set the foundation for evaluating potential HLA Class I molecules in complex with peptides/antigens that may initiate or interfere with T-cell responses.

We observed substantial differences in predicted Major Histocompatibility Complex II (MHCII) epitope presentation of SARS-CoV-2 proteins for different populations but only minor differences in predicted MHCI epitope presentation. A comparison of this predicted epitope MHC-coverage revealed for the early phase of infection spread (till day 15 after reaching 128 observed infection cases) highly significant negative correlations with the case fatality rate. Specifically, this was observed in different populations for MHC class II presentation of the viral spike protein (p-value: 0.0733 for linear regression), the envelope protein (p-value: 0.023), and the membrane protein (p-value: 0.00053), indicating that the high case fatality rates of COVID-19 observed in some countries seem to be related with poor MHC class II presentation and hence weak adaptive immune response against these viral envelope proteins. Our results highlight the general importance of the SARS-CoV-2 structural proteins in immunological control in early infection spread looking at a global census in various countries and taking case fatality rate into account. Other factors such as health system and control measures become more important after the early spread. Our study should encourage further studies on MHCII alleles as potential risk factors in COVID-19 including assessment of local populations and specific allele distributions.

BACKGROUND: Hereditary hemochromatosis is an autosomal recessive disorder where the clinical phenotype of skin pigmentation and organ damage occurs only in homozygotes. Simple heterozygotes, that is, just C282Y, typically do not develop iron overload. Here we present a case where a simple heterozygote in combination with alcoholism developed high ferritin and high transferrin saturation levels indicative of iron overload. Though alcoholism alone could explain her presentation, we hypothesize that an inflammatory cocktail of iron and alcohol probably caused our patient to succumb to acute liver failure at a very young age.
METHODS: A 29-year-old Caucasian woman presented to the hospital with progressively worsening yellowish discoloration of her eyes and skin associated with anorexia, nausea, vomiting, diffuse abdominal discomfort, increasing abdominal girth, dark urine and pale stools for about 2 weeks. Family history was significant for hereditary hemochromatosis. Her father was a simple heterozygote and her grandmother was homozygous for C282Y. Physical examination showed scleral icterus, distended abdomen with hepatomegaly and mild generalized tenderness. Lab test results showed an elevated white blood cell count, ferritin 539 ng/dL, transferrin saturation 58.23%, elevated liver enzymes, elevated international normalized ratio (INR), low albumin, Alcoholic Liver Disease/Nonalcoholic Fatty Liver Disease (ALD/NAFLD) Index (ANI) of 2.6, suggesting a 93.2% probability of alcoholic liver disease, and phosphatidyl ethanol level of 537ng/ml. Genetic testing showed that the patient was heterozygous for human homeostatic iron regulator protein (HFE) C282Y mutation and the normal allele. Computed tomography (CT) of the abdomen revealed hepatomegaly, portal hypertension and generalized anasarca. Magnetic resonance cholangiopancreatography (MRCP) showed negative results for bile duct pathology. Workup for other causes of liver disease was negative. A diagnosis of acute alcoholic hepatitis was made, with Maddrey\'s discriminant function of > 32, so prednisolone was started. Her bilirubin and INR continued to increase despite steroids, and the patient unfortunately died.
CONCLUSIONS: Our case highlights the importance of considering hemochromatosis in the differential diagnosis of young patients presenting with liver failure, including cases suggestive of alcoholism as the likely etiology. Larger studies are needed to investigate the role of non-iron factors like alcohol and viral hepatitis in the progression of liver disease in simple heterozygotes with hereditary hemochromatosis, given the high prevalence of this mutation in persons of Northern European descent.

More than twenty years ago the reverse vaccinology paradigm came to light trying to design new vaccines based on the analysis of genomic information in order to select those pathogen peptides able to trigger an immune response. In this context, focusing on the proteome of Trypanosoma cruzi, we investigated the link between the probabilities for pathogen peptides to be presented on a cell surface and their distance from human self. We found a reasonable but, as far as we know, undiscovered property: the farther the distance between a peptide and the human-self the higher the probability for that peptide to be presented on a cell surface. We also found that the most distant peptides from human self bind, on average, a broader collection of HLAs than expected, implying a potential immunological role in a large portion of individuals. Finally, introducing a novel quantitative indicator for a peptide to measure its potential immunological role, we proposed a pool of peptides that could be potential epitopes and that can be suitable for experimental testing. The software to compute peptide classes according to the distance from human self is free available at http://www.iasi.cnr.it/~dsantoni/nullomers.

Recent reports have identified that the presence of non-native conformation HLA to which antibody can bind upon Luminex HLA Class I single antigen beads, can vary in levels between different manufacturers kits and that the prozone effect may also be specific to particular products. We present a case in which both prozone and non-native HLA reactive antibodies were observed, which raises important questions on how SAB assays are utilised, especially in the post-transplant monitoring setting. A 56-year old, highly sensitised female patient awaiting a regraft received a HLAi renal transplant. Post-transplant monitoring showed discordant results between two SAB manufacturers assays, with one assay identifying a potential de novo HLA DSA. HLA Class I antibody reactivity was observed which was directed towards the Bw6 public epitope, which is present upon HLA molecules encoded for by numerous HLA-B alleles. However in the day 19 post-transplant sample reactivity spread beyond the Bw6 epitope. To investigate the possibility of a prozone type effect influencing the testing kit the day 19 post-transplant sample was diluted 1:10 with PBS and reanalysed. After dilution the Bw6 reactivity was observed again, however the suspect de novo DSA still persisted. An analysis of the mismatched epitopes identified one manufacturer\'s assay as being confounded by the presence of denatured reactivity as well as prozone.

Pancreatic tumor cells may avoid immune surveillance by releasing the transmembrane major histocompatibility complex class I chain-related A (MICA) protein in soluble form (s-MICA). We hypothesized that the presence of the A5.1 polymorphism in the MICA gene, which encodes a truncated MICA protein, is associated with higher s-MICA levels and increased pancreatic cancer risk.
MICA alleles and s-MICA levels were measured in 121 pancreatic cancer cases and 419 controls. General linear regression with a log transformation assessed geometric means of s-MICA levels across MICA alleles. Unconditional logistic regression was used to calculate the odds ratio (OR) and 95% confidence intervals (CI) for pancreatic cancer associated with MICA alleles.
After multivariate adjustment, participants with at least one copy of the A5.1 allele versus no A5.1 allele had 1.35 (95% CI: 1.05-1.74) times greater s-MICA levels (1.65 times higher for cases and 1.28, for controls) and increased risk of pancreatic cancer (OR = 1.91, 95% CI: 1.05-3.48).
Our study suggests higher risk of pancreatic cancer among those with the MICA A5.1 polymorphism, which may be explained by an increase in s-MICA secretion and impaired immune response.
These findings provide further evidence at the genetic and molecular level of the important role of MICA in pancreatic cancer development, and may have important implications with regards to pancreatic cancer screening.

BACKGROUND: Merkel cell carcinoma (MCC) is an aggressive skin cancer in which PD-1/PD-L1 blockade has shown remarkable response rates. However, a significant proportion of patients shows primary or secondary resistance against PD-1/PD-L1 inhibition, with HLA class-I downregulation and insufficient influx of CD8+ T cells into the tumor as possible immune escape mechanisms. Histone deacetylase inhibitors (HDACi) have been demonstrated to reverse low HLA class-I expression caused by epigenetic downregulation of the antigen machinery (APM) in vitro and in pre-clinical models in vivo.
METHODS: We report four cases of patients with metastatic MCC who did not respond to immunotherapy by PD-1/PD-L1 blockade. Two of the patients received, subsequently, the HDACi panobinostat in combination with PD-1/PD-L1 blockade. Tumor biopsies of the patients were analyzed for cellular and molecular markers of antigen processing and presentation as well as the degree of T-cell infiltration.
CONCLUSIONS: Low expression of APM-related genes associated with low HLA class-I surface expression was observed in all MCC patients, progressing on PD-1/PD-L1 blockade. In one evaluable patient, of the two treated with the combination therapy of the HDACi, panobinostat and PD-1/PD-L1 blockade, reintroduction of HLA class-I-related genes, enhanced HLA class-I surface expression, and elevated CD8+ T-cell infiltration into the MCC tumor tissue were observed; however, these changes did not translate into a clinical benefit. Our findings suggest that HDACi may be useful to overcome HLA class-I downregulation as a resistance mechanism against anti-PD-1/PD-L1 antibodies in MCC patients. Prospective clinical trials are needed to evaluate this notion.