Effect Of Human Leukocyte Antigen Research Articles

The Effect of Human Leukocyte Antigen in Development of Systemic Lupus Erythematosus in Patients

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by the production of autoantibodies against nuclear antigens and a systemic inflammation that can damage a broad spectrum of organs. SLE patients suffer from a wide variety of symptoms, which can affect virtually almost any tissue. As lupus is difficult to diagnose, the worldwide prevalence of SLE can only be roughly estimated to range from 10 and 200 cases per 100,000 individuals with dramatic differences depending on gender, ethnicity, and location. Although the treatment of this disease has been significantly ameliorated by new therapies, improved conventional drug therapy options, and a trained expert eye, the underlying pathogenesis of lupus still remain widely unknown. The complex etiology reflects the complex genetic background of the disease, which is also not well understood yet. However, in the past few years advances in lupus genetics have been made, notably with the publication of genome wide association studies in humans.

Protective and Susceptibility Effects of Human Leukocyte Antigen on Melanoma Prevalence and their Implications for Predicting Checkpoint Blockade Immunotherapy Outcomes

The association of Human Leukocyte Antigen (HLA) with melanoma has been well documented. Similarly, the outcome of checkpoint blockade immunotherapy (CBI) in melanoma depends, to some extent, on the HLA genotype of the patient. Although specific favorable (or unfavorable) HLA alleles for CBI outcome for melanoma have been identified, there is currently no reliable way to predict a positive, neutral or negative melanoma CBI outcome for other alleles. Here we used an immunogenetic epidemiological approach to identify HLA alleles whose frequency is negatively (or positively) associated with melanoma prevalence (protective or susceptibility alleles, respectively). The findings demonstrated that, indeed, HLA alleles that are negatively associated with melanoma prevalence in the population have been associated with good CBI outcome at the individual level and, conversely, HLA alleles that are positively associated with melanoma prevalence have been associated with poor CBI outcome in individuals. Given this good prediction of CBI cancer immunotherapy by specific immunogenetically discovered HLA alleles, we used this epidemiologic immunogenetic approach to identify more HLA Class I and II alleles protective (or susceptibility) for melanoma which would thus be good predictors of CBI outcomes in those cancers. This is a new approach to successfully (a) identify HLA protective or susceptibility alleles for melanoma, and (b) use that information in anticipating outcomes in CBI cancer immunotherapy.

Long-term survival in non-human primates of stem cell-derived, MHC-unmatched corneal epithelial cell sheets.

SummaryWhen corneal epithelial stem cells residing in the corneal limbus become dysfunctional, called a limbal stem cell deficiency (LSCD), corneal transparency is decreased, causing severe vision loss. Transplantation of corneal epithelial cell sheets (CEPS) derived from stem cells, including induced pluripotent stem cells, is a promising treatment for LSCD. However, the potential effect of human leukocyte antigen (HLA) concordance on CEPS transplantation has not been addressed. Here, we show that there is no difference in the immune response to CEPS between HLA-matched and -unmatched peripheral blood mononuclear cells in mixed lymphocyte reactions. CEPS transplantation in cynomolgus monkeys revealed that the immune response to major histocompatibility-unmatched CEPS was not strong and could be controlled by local steroid administration. Furthermore, programmed death ligand 1 was identified as an immunosuppressive molecule in CEPS under inflammatory conditions in vitro. Our results indicate that corneal epithelium has low immunogenicity and allogeneic CEPS transplantation requires mild immunosuppression.

Association between HLA alleles and sub-phenotype of childhood steroid-sensitive nephrotic syndrome

BackgroundFew studies have addressed the effects of human leukocyte antigen (HLA) alleles on different clinical sub-phenotypes in childhood steroid-sensitive nephrotic syndrome (SSNS), including SSNS without recurrence (SSNSWR) and steroid-dependent nephrotic syndrome/frequently relapse nephrotic syndrome (SDNS/FRNS). In this study, we investigated the relationship between HLA system and children with SSNSWR and SDNS/FRNS and clarified the value of HLA allele detection for precise typing of childhood SSNS.MethodsA total of 241 Chinese Han individuals with SSNS were genotyped using GenCap-WES Capture Kit, and four-digit resolution HLA alleles were imputed from available Genome Wide Association data. The distribution and carrying frequency of HLA alleles in SSNSWR and SDNS/FRNS were investigated. Additionally, logistic regression and mediating effects were used to examine the relationship between risk factors for disease process and HLA system.ResultsCompared with SSNSWR, significantly decreased serum levels of complement 3 (C3) and complement 4 (C4) at onset were detected in SDNS/FRNS (C3, P < 0.001; C4, P = 0.018). The average time to remission after sufficient initial steroid treatment in SDNS/FRNS was significantly longer than that in SSNSWR (P = 0.0001). Low level of C4 was further identified as an independent risk factor for SDNS/FRNS (P = 0.008, odds ratio = 0.174, 95% confidence interval 0.048–0.630). The HLA-A*11:01 allele was independently associated with SSNSWR and SDNS/FRNS (P = 0.0012 and P = 0.0006, respectively). No significant HLA alleles were detected between SSNSWR and SDNS/FRNS. In addition, a mediating effect among HLA-I alleles (HLA-B*15:11, HLA-B*44:03 and HLA-C*07:06), C4 level and SDNS/FRNS was identified.ConclusionsHLA-I alleles provide novel genetic markers for SSNSWR and SDNS/FRNS. HLA-I antigens may be involved in steroid dependent or frequent relapse in children with SSNS as mediators of immunoregulation.

Impact of Human Leukocyte Antigen Epitope Matching on Outcomes after Unrelated Bone Marrow Transplantation

Impact of Human Leukocyte Antigen Epitope Matching on Outcomes after Unrelated Bone Marrow Transplantation

Human Leukocyte Antigen (HLA) Influence on Prognosis of Autoimmune Hearing Loss.

Background: To evaluate the effect of human leukocyte antigen (HLA) on hearing outcome in patients suffering from autoimmune hearing loss (AIHL). Materials and Methods: The diagnosis of AIHL was essentially based on clinical symptoms, such as recurrent, sudden, fluctuating, or quickly progressing (<12 months) sensorineural hearing loss (uni-/bilateral). The molecular typing of HLA alleles was achieved by using polymerase chain reaction procedures. Patients underwent a tapering schema of steroid treatment and audiometric features were recorded. A logistic regression model was used to identify which HLA typing alleles were statistically significant in patients’ response to treatment. Results: Forty patients with AIHL were found to be carriers of HLA B27, B35, B51, C4, C7, and DRB1*04 alleles. No statistically significant influence of HLA B27, B35, B51, C4, C7, DRB1*04 HLA alleles typing was detected for the prognosis of AIHL. In these patients, the onset of AIHL was mainly progressive (53.8%), 29.2% of them had moderate hearing loss, and most of the cases had both bilateral hearing loss (62.5%) and downsloping audiogram (40%). Conclusion: The presence of HLA B27, B35, B51, C4, C7, and DRB1*04 alleles had no significant effect on a favorable outcome of AIHL. However, larger samples of patients are necessary in order to improve the knowledge about the HLA influence on the clinical course of AIHL.

Impact of HLA class I allele-level mismatch on viral infection within 100\xa0days after cord blood transplantation

Viral infection is more frequently reported in cord blood transplantation (CBT) than in transplantation of other stem cell sources, but its precise mechanism related to antiviral host defenses has not been elucidated yet. To evaluate the effect of human leukocyte antigen (HLA) class I allele-level incompatibility on viral infection in CBT, we conducted a single-center retrospective study. Total 94 patients were included, and viral infections were detected in 32 patients (34%) within 100 days after CBT. HLA-C mismatches in graft-versus-host direction showed a significantly higher incidence of viral infection (hazard ratio (HR), 3.67; p = 0.01), while mismatches in HLA-A, -B, or -DRB1 were not significant. Overall HLA class I mismatch was also a significant risk factor and the predictor of post-CBT viral infection (≥ 3 mismatches, HR 2.38, p = 0.02), probably due to the insufficient cytotoxic T cell recognition and dendritic cell priming. Patients with viral infection had significantly worse overall survival (52.7% vs. 72.1%; p = 0.02), and higher non-relapse mortality (29.3% vs. 9.8%; p = 0.01) at 5 years. Our findings suggest that appropriate graft selection as well as prophylaxis and early intervention for viral infection in such high-risk patients with ≥ 3 HLA class I allele-level mismatches, including HLA-C, may improve CBT outcomes.

Impact of human leukocyte antigen and calculated panel reactive antibody on BK viremia in kidney transplant recipients: A single‐center experience and literature review

The aim of this retrospective analysis was to investigate the effect of human leukocyte antigen (HLA) and calculated panel reactive antibody (cPRA) on BK virus activation as evidenced by BK viremia (BKV). At our institution, 649 kidney transplant patients were screened for BKV from 2009 to 2017. Patients were considered to have BKV if they had >10000 copies/mL of BK DNA in their blood. Donor and recipient HLA and cPRA, demographic, clinical and laboratory data, as well as immunosuppressive medications were collected. We identified 122 BK positive and 527 BK negative patients. Only 25% of the patients had cPRA of 20% or more, and 64% had more than three HLA-A, -B, and -DR mismatches. In both univariate and multivariate analyses, male gender, age, and maintenance of steroid therapy significantly increased the risk of BKV (P=0.005, 0.005 and <0.001, respectively). The degree of cPRA and the individual HLA allele and HLA allele matching did not significantly affect BKV. Neither the degree of HLA mismatching nor cPRA appears to affect BKV. Moreover, no specific HLA allele, HLA allele matching, or cPRA were associated with BKV.

What is the impact of human leukocyte antigen mismatching on graft survival and mortality in renal transplantation? A meta-analysis of 23 cohort studies involving 486,608 recipients

sBackgroundThe magnitude effects of human leukocyte antigen (HLA) mismatching on post-transplant outcomes of kidney transplantation remain controversial. We aim to quantitatively assess the associations of HLA mismatching with graft survival and mortality in adult kidney transplantation.MethodsWe searched PubMed, EMBASE and the Cochrane Library from their inception to December, 2016. Priori clinical outcomes were overall graft failure, death-censored graft failure and all-cause mortality.ResultsA total of 23 cohort studies covering 486,608 recipients were selected. HLA per mismatch was significant associated with increased risks of overall graft failure (hazard ratio (HR), 1.06; 95% confidence interval (CI), 1.05–1.07), death-censored graft failure (HR: 1.09; 95% CI 1.06–1.12) and all-cause mortality (HR: 1.04; 95% CI: 1.02–1.07). Besides, HLA-DR mismatches were significant associated with worse overall graft survival (HR: 1.12, 95% CI: 1.05–1.21). For HLA-A locus, the association was insignificant (HR: 1.06; 95% CI: 0.98–1.14). We observed no significant association between HLA-B locus and overall graft failure (HR: 1.01; 95% CI: 0.90–1.15). In subgroup analyses, we found recipient sample size and ethnicity maybe the potential sources of heterogeneity.ConclusionsHLA mismatching was still a critical prognostic factor that affects graft and recipient survival. HLA-DR mismatching has a substantial impact on recipient’s graft survival. HLA-A mismatching has minor but insignificant impact on graft survival outcomes.

Effect of human leukocyte antigen mismatching on the outcomes of pediatric kidney transplantation: a systematic review and meta-analysis.

Kidney transplantation is regarded as the optimal treatment for pediatric patients with end-stage renal disease. Here, we address a controversial topic in pediatric kidney transplantation by performing a quantitative evaluation of the effect of human leukocyte antigen (HLA) mismatching on the outcomes of pediatric kidney transplantation. We systematically searched PubMed, EMBASE and the Cochrane Library from their inception to 31 December 2016 for cohort studies assessing the risk ratio (RR) of HLA mismatching on pediatric kidney transplantation. Outcome measures included graft failure, rejection and all-cause mortality. RRs and 95% confidence intervals (CIs) were used as estimates of effect size in random-effect models. Eighteen studies comprising a total of 26 018 pediatric recipients were included in the evaluation. Compared with 0-1 HLA-DR mismatch, 2 mismatches significantly increased the risk of graft failure at 1 year (RR: 1.41, 95% CI: 1.11-1.80), 3 years (RR: 1.28, 95% CI: 1.08-1.52), 5 years (RR: 1.21, 95% CI: 1.04-1.41) and 10 years (RR: 1.30, 95% CI: 1.02-1.67). For HLA-A + B, the 5-year graft failure risk was higher for 2-4 mismatches compared with 0-1 mismatch (RR: 3.17, 95% CI: 1.20-8.36), but not for 3-4 compared with 0-2 mismatches (RR: 1.49, 95% CI: 0.79-2.80). Based on pooled analysis, HLA-DR and HLA-A + B are important factors affecting post-transplant outcomes, especially graft failure, in pediatric recipients. Additional randomized controlled trials with higher quality evidence are needed for further investigation.

Effect of human leukocyte antigen-F associated transcript 10 on the proliferation and apoptosis of thyroid carcinoma cells

Objective To observe the effects of human leukocyte antigen (HLA)-F associated transcript 10 (FAT10)ΔGG, a carboxyl-terminal diglycine deficient mutant, on the proliferation and apoptosis of thyroid carcinoma cell line TPC-1. Methods Specimens of cervical carcinoma in situ and normal thyroid tissue, 10 each, were collected. The expression levels of FAT10 protein in these specimens were detected by Western blotting. Site-directed mutagenesis was applied to construct the mutant pcDNA3.0-flag-FAT10ΔGG plasmid. The TPC-1 cells were then transiently transfected with wild-type FAT10, FAT10ΔGG and empty vector (used as negative control), and the wild-type TPC-1 cells served as blank control group. The transfection efficiency of FAT10 or FAT10ΔGG was detected by Western blotting, and cell proliferation was determined by cell counting kit-8 (CCK-8) assay. Cisplatin was used to induce cells after cells were transfected for 24 h, and the cell apoptotic rate was examined by flow cytometry. Results Western blotting showed a significantly increased expression of FAT10 protein in cervical carcinoma tissues as compared with that in normal cervical tissues. Over-expression of wild FAT10 in TPC-1 cells obviously promoted cell proliferation, but this promotion was significantly inhibited in cells transfected with its diglycine mutant. As compared with blank control group [(22.7±4.2)%] and negative control group [(24.1±3.8)%], the apoptotic rate was significantly reduced in wild FAT10 group [(10.9±2.0)%, P 0.05]. Conclusion FAT10 can promote cell proliferation and inhibit cell apoptosis through its carboxyl-terminal diglycine motif, and it may play an essential role in carcinogenesis and development of cancer. Key words: Thyroid carcinoma; Human leukocyte antigen-F associated transcript 10; Apoptosis

The effect of human leukocyte antigen G alleles on human papillomavirus infection and persistence in a cohort of HIV-positive pregnant women from Brazil

Patients with compromised immune systems have more severe intraepithelial lesions and more rapid disease progression, in addition to increased risk for cervical cancer. Persistent infection by the human papillomavirus (HPV) is a necessary step in that process. By inducing expression of inhibitory ligands of natural killer cells, like HLA-G, HPV avoids the elimination of infected cells. Recent studies have investigated polymorphisms in HLA-G that may be associated with susceptibility to HPV infection and persistence. One hundred-forty HIV+ pregnant women from Brazil had a DNA fragment comprising HLA-G exons 2-4 PCR-amplified, cloned, sequenced and analyzed for allele determination. Altogether, 22 alleles comprising 52 different genotypes were found. Four novel HLA-G alleles were characterized. We have not observed association of specific HLA-G alleles with HPV infection, but found a protective effect of the G:01:01:02 allele against the occurrence of intraepithelial lesions. In addition to describing new HLA-G alleles and defining new reference sequences, our data provide a better understanding of the impact of HLA-G alleles on HPV-related disease.

Association of HLA-DQA1 and -DQB1 alleles with type I diabetes in Arabs: a meta-analyses.

This study aimed at assessing the nature and significance of associations between various alleles of HLA-DQA1, HLA-DQB1, and type I diabetes (T1D) in Arab populations. Evidence from literature (published before 20 April 2015) was amassed and analysed through multiple meta-analyses, which yielded effect summary odds ratios and 95% confidence intervals for 24 alleles and 4 haplotypes. A total of 1273 cases and 1747 controls from 16 studies were analysed. High levels of significance were obtained to support higher T1D risk when harbouring DQA1*03:01. The alleles DQB1*02:01 and *03:02 and the haplotypes DR3 and DR4 were significant risk factors, albeit with high publication heterogeneity. The protective effects of DQA1*01:01, DQB1*05:03, *06:02, *06:03, and *06:04 were robustly suggested by all indicators of meta-analyses. The haplotypes DR7 and DR11 were strongly suggested to be protective in Arabs. A relatively small number of studies have emerged from Arab countries, mostly with inadequate power on an individual basis. This study fills the gap by providing significant size effect of human leukocyte antigen (HLA) alleles and completes the continuum of global ethnic differences in this context.

Grouping of large populations into few CTL immune 'response-types' from influenza H1N1 genome analysis.

Despite extensive work on influenza, a number of questions still remain open about why individuals are differently susceptible to the disease and why only some strains lead to epidemics. Here we study the effect of human leukocyte antigen (HLA) genotype heterogeneity on possible cytotoxic T-lymphocyte (CTL) response to 186 influenza H1N1 genomes. To enable such analysis, we reconstruct HLA genotypes in different populations using a probabilistic method. We find that epidemic strains in general correlate with poor CTL response in populations. Our analysis shows that large populations can be classified into a small number of groups called response-types, specific to a given viral strain. Individuals of a response-type are expected to exhibit similar CTL responses. Extent of CTL responses varies significantly across different populations and increases with increase in genetic heterogeneity. Overall, our analysis presents a conceptual advance towards understanding how genetic heterogeneity influences disease susceptibility in individuals and in populations. We also obtain lists of top-ranking epitopes and proteins, ranked on the basis of conservation, antigenic cross-reactivity and population coverage, which provide ready short-lists for rational vaccine design. Our method is fairly generic and has the potential to be applied for studying other viruses.

Association of human leukocyte antigen DQB1 and DRB1 alleles with chronic hepatitis B.

To investigate the effect of human leukocyte antigen (HLA) DRB1 and DQB1 alleles on the inactive and advanced stages of chronic hepatitis B. Patient records at a single institution's hepatology clinic were reviewed. Demographic data, laboratory results, endoscopy results, virological parameters, biopsy scores and treatment statuses were recorded. In total, 355 patients were eligible for the study, of whom 226 (63.7%) were male. Overall, 82 (23.1%) were hepatitis B early antigen (HBeAg) positive, 87 (24.5%) had cirrhosis, and 66 (18.6%) had inactive disease. The presence of DQB1 and DRB1 alleles was determined by polymerase chain reaction with sequence-specific primers. The distribution of the genotyped alleles among patients with cirrhosis and patients with chronic active hepatitis was analyzed. The most frequent HLA DQB1 allele was DQB1*03:01 (48.2%), and the most frequent HLA DRB1 allele was DRB1*13/14 (51.8%). DQB1*05:01 was more frequent in patients with active disease than in inactive patients (27% vs 9.1%; P = 0.002, Pc = 0.026). DRB1*07 was rare in patients with cirrhosis compared with non-cirrhotics (3.4% vs 16%; P = 0.002, Pc = 0.022). Older age (P < 0.001) and male gender (P = 0.008) were the other factors that affected the presence of cirrhosis. In a multivariate logistic regression analysis, DRB1*07 remained a significant negative predictor of cirrhosis (P = 0.015). A bioinformatics analysis revealed that a polymorphic amino acid sequence in DRB1*07 may alter interaction with the T-cell recognition site. This study demonstrates that HLA alleles may influence cirrhosis development and disease activity in Turkish chronic hepatitis B patients.

HLA-DQB1*03 Confers Susceptibility to Chronic Hepatitis C in Japanese: A Genome-Wide Association Study

Hepatitis C virus (HCV) establishes a chronic infection in 70-80% of infected individuals. Many researchers have examined the effect of human leukocyte antigen (HLA) on viral persistence because of its critical role in the immune response against exposure to HCV, but almost all studies have proven to be inconclusive. To identify genetic risk factors for chronic HCV infection, we analyzed 458,207 single nucleotide polymorphisms (SNPs) in 481 chronic HCV patients and 2,963 controls in a Japanese cohort. Next, we performed a replication study with an independent panel of 4,358 cases and 1,114 controls. We further confirmed the association in 1,379 cases and 25,817 controls. In the GWAS phase, we found 17 SNPs that showed suggestive association (P < 1 × 10-5). After the first replication study, we found one intronic SNP in the HLA-DQ locus associated with chronic HCV infection, and when we combined the two studies, the association reached the level of genome-wide significance. In the second replication study, we again confirmed the association (P combined = 3.59 × 10−16, odds ratio [OR] = 0.79). Subsequent analysis revealed another SNP, rs1130380, with a stronger association (OR=0.72). This nucleotide substitution causes an amino acid substitution (R55P) in the HLA-DQB1 protein specific to the DQB1*03 allele, which is common worldwide. In addition, we confirmed an association with the previously reported IFNL3-IFNL4 locus and propose that the effect of DQB1*03 on HCV persistence might be affected by the IFNL4 polymorphism. Our findings suggest that a common amino acid substitution in HLA-DQB1 affects susceptibility to chronic infection with HCV in the Japanese population and may not be independent of the IFNL4 genotype.

HLA class I antibody-mediated endothelial and smooth muscle cell activation

Advances in immunosuppression and patient management have successfully improved 1-year transplant outcome. Unfortunately, antibody-mediated rejection is a major barrier to long-term graft survival. This study summarizes the effects of antibodies on endothelial cell and smooth muscle cell (SMC) migration, proliferation and leukocyte recruitment, emphasizing the intracellular signaling pathways that orchestrate these distinct functional outcomes. Several studies have provided further insight into the effects of human leukocyte antigen (HLA) class I antibodies on vascular cells. We found that HLA I molecules partner with integrin β4 to transduce proliferative signaling, and identified proteins that associate with the cytoskeleton after HLA class I crosslinking. Natural killer cells have been strongly implicated in a murine model of donor-specific major histocompatibility complex I antibody-triggered neointimal thickening. A recently developed human arterial graft model revealed the role of matrix metalloproteinases in SMC mitogenesis by HLA class I antibodies. Using a donor transgenic for HLA-A2, Fukami et al. investigated the mechanisms of accommodation induced by low titers of HLA class I antibodies. Ligation of HLA class I molecules with antibodies leads to the activation of intracellular signals in endothelial cells and SMCs, which in turn promote actin cytoskeletal remodeling, survival, proliferation, and recruitment of leukocytes.

Decreased humoral antibody episodes of acute renal allograft rejection in recipients expressing the HLA-DQβ1*0202 allele

The present investigation was designed to show the effect of human leukocyte antigen (HLA) class II molecular allelic specificities in the recipient on the induction of humoral antibody rejection, identified by C4d peritubular capillary staining, as well as specific antibody identified by Luminex technology. Major histocompatibility complex (MHC) class II molecules are expressed on dendritic cells, macrophages, and B lymphocytes and they present antigenic peptides to CD4 positive T lymphocytes. Human renal peritubular and glomerular capillaries express class II MHC molecules upon activation. Expression of class II molecules on renal microvascular endothelial cells exposes them to possible interaction with specific circulating antibodies. We hypothesize that HLA-DQβ1*0202 expression in recipients decreases the likelihood of antibody-mediated renal allograft rejection. We found that 80% (=25) of DQ2 positive haplotype recipients failed to induce humoral antibody renal allograft rejection and 20% (n=25) of DQ2 positive haplotype recipients induced humoral antibody renal allograft rejection (p=0.008). By contrast, 48% (n=46) of DQ2 negative haplotype recipients failed to induce a humoral antibody component of renal allograft rejection and 52% (n=46) of DQ2 negative haplotype recipients induced humoral antibody-mediated renal allograft rejection. Our results suggest that recipients who express the DQβ1*0202 allele are less likely to induce a humoral antibody component of acute renal allograft rejection than are those expressing DQ1, DQ3, or DQ4 alleles. DQβ1*0202 allele expression in recipients could possibly be protective against acute humoral allograft rejection and might serve as a future criterion in recipient selection and in appropriate therapy for acute renal rejection episodes.

Investigation of the Effect of Human Leukocyte Antigen on the Development of Neutralizing Antibodies in Interferon-beta Treated Patients with Multiple Sclerosis (*The First Three Authors Contributed Equally to This Work) (P05.121)

Objective: Investigate if certain human leukocyte antigen (HLA) class I and II allele groups are associated with the susceptibility to develop neutralizing antibodies (NAbs) in a Swedish cohort of patients with multiple sclerosis (MS) treated with interferon-beta (IFN-beta) and whether or not an association with clinically relevant NAb-titers exists. Background A proportion of MS patients receiving IFN-beta therapy develop NAbs that interfere with treatment efficacy. However, NAbs only occur in a subset of patients, which indicates that factors like the carrying of different HLA allele groups could be involved in determining the risk for developing NAbs. Design/Methods: 1066 patients with NAb-status, from the Swedish NAb-registry, and HLA genotype data were included. Patients were regarded as NAb-positive when having at least one positive sample. Negativity was defined as never having a positive titer, with either one negative sample taken 24±3 months after the start of IFN-beta treatment or two negative samples taken between 6 to 21 and 27 to 36 months after treatment start. 419 patients matched these criteria of which 230 were NAb-positive and 189 NAb-negative. Cut-off for clinical relevant titers was a NAb-titer higher than 150 TRU/ml. The frequency distribution for each allele was analyzed by chi-square and odds ratio was assessed with 95% confidence interval, p Results: No significant association could be found between allele group frequency distribution and the development of NAbs, neither with nor without correcting for treatment. However, HLA-DRB1*15 was associated with clinically relevant titers (OR 1.45, p-value 0.036). Conclusions: NAb development being associated with specific allele groups, as described in earlier studies, could not be replicated but our results indicate that the development of clinically relevant titers is associated with HLA-DRB1*15. Knowing this could help when choosing newer substitute medications for IFN-beta. Disclosure: Dr. Fink has received research support from Biogen Idec. Dr. Lundkvist has received research support from Biogen Idec. Ms. Link has received research support from Karolinska Institutet. Dr. Kockum has nothing to disclose. Dr. Hermanrud has nothing to disclose. Dr. Brynedal has received research support from the Swedish Research Council. Dr. Hillert has received personal compensation for activities with Biogen Idec, Merck-Serono, Novartis and Teva Neuroscience as participant on advisory boards, consulting and/or speaking engagements.Dr. Hillert has received research support from Sanofi-Aventis Pharmaceuticals, Inc., Bayer Pharmaceuticals Corporation, Biogen Idec and Merck-Serono. Dr. Fogdell has received research support from Biogen Idec, Merck Serono, and Sanofi-Aventis Pharmaceuticals, Inc.

HLA Alleles are Associated With Altered Risk for Disease Progression and Central Nervous System Impairment of HIV-Infected Children

To examine the effects of human leukocyte antigen (HLA) alleles on HIV-1-related disease progression and central nervous system (CNS) impairment in children. Five hundred seventy-two HIV-1-infected children, identified as disease progressors or nonprogressors, were selected from PACTG P152 and P300 through a case-cohort sampling scheme. Study endpoints were HIV-1-related disease progression-free survival and time to CNS impairment. DNA was genotyped for HLA alleles using a Luminex 100 platform. Weighted Kaplan-Meier methods, and Cox proportional hazards models were used to assess the effects of HLA alleles on study endpoints. Presence of the B-27 allele (n = 20) was associated with complete protection against disease progression and CNS impairment over the median follow-up of 26 months (P < 0.0001 for both). These findings held in multivariate analyses controlling for baseline covariates including race, gender, age, log HIV-1 RNA, CD4 lymphocyte count and percent, weight for age z score and treatment, and for other genotypes shown to affect HIV-1-related disease progression. Also, although the Cw-2 allele protected against disease progression [Hazard ratio (HR), 0.48; 95% confidence interval (CI): 0.28 to 0.81; P = 0.006], the A-24 allele was associated with more rapid CNS impairment (HR: 2.01; 95% CI: 1.04 to 3.88; P = 0.04). The HLA class II DQB1-2 allele was associated with a delayed disease progression (HR: 0.66; 95% CI: 0.47-0.92; P = 0.01) and CNS impairment (HR: 0.58; 95% CI: 0.36 to 0.93; P = 0.02). Presence of B-27, Cw-2, or DQB1-2 alleles was associated with delayed HIV-1 disease progression, while B-27, A-24, and DQB1-2 alleles were associated with altered progression to CNS impairment in children.