HLA class II peptide-binding-region analysis reveals funneling of polymorphism in action.

BACKGROUND: HLA-class II proteins hold important roles in key physiological processes. The purpose of this study was to compile all class II alleles reported in human population and investigate patterns in pocket variants and their combinations, focusing on the peptide-binding region (PBR). METHODS: For this purpose, all protein sequences of DPA1, DQA1, DPB1, DQB1 and DRB1 were selected and filtered, in order to have full PBR sequences. Proportional representation was used for pocket variants while population data were also used. RESULTS: All pocket variants and PBR sequences were retrieved and analyzed based on the preference of amino acids and their properties in all pocket positions. The observed number of pocket variants combinations was much lower than the possible inferred, suggesting that PBR formation is under strict funneling. Also, although class II proteins are very polymorphic, in the majority of the reported alleles in all populations, a significantly less polymorphic pocket core was found. CONCLUSIONS: Pocket variability of five HLA class II proteins was studied revealing favorable properties of each protein. The actual PBR sequences of HLA class II proteins appear to be governed by restrictions that lead to the establishment of only a fraction of the possible combinations and the polymorphism recorded is the result of intense funneling based on function.

Identifying the HLA DRB1-DQB1 molecules and predicting epitopes associated with high-risk HPV infection clearance and redetection.

Several determining factors are involved in HPV infection outcomes; human leukocyte antigen (HLA) polymorphisms have been described as related factors. This study has ascertained the effect of genetic variation on HLA-DRB1 and DQB1 genes on HPV-16/-18/-31/-33/-45 and -58 clearance and redetection in Colombian women. PCR and qPCR were used for viral identification and the Illumina MiSeq system was used for HLA-typing of cervical samples (n = 276). Survival models were adjusted for identifying alleles/haplotypes related to HPV clearance/redetection; L1/L2 protein-epitope binding to MHC-II molecules was also predicted. Significant associations suggested effects favouring or hampering clearance/redetection events depending on the viral type involved in infection, e.g. just DRB1*12:01:01G favoured HPV-16 (coeff: 4.8) and HPV-45 clearance (coeff: 12.65) whilst HPV-18 (coeff: 2E-15), HPV-31 (coeff: 8E-17) and HPV-58 hindered elimination (coeff: 1E-14). An effect was only observed for some alelles when configured as haplotypes, e.g. DRB1*04:07:01G (having the greatest frequency in the target population) was associated with DQB1*02:01:1G or *03:02:03. Epitope prediction identified 23 clearance-related peptides and 29 were redetection-related; eight might have been related to HPV-16/-18 and -58 persistence and one to HPV-18 elimination. HLA allele/haplotype relationship with the course of HPV infection (clearance/redetection) depended on the infecting HPV type, in line with the specific viral epitopes displayed.

Successful Treatment of Antibody-Mediated Rejection by De Novo Donor Specific Antibody After Primary Renal Transplantation in a Recipient From a Cadaveric Donor: A Case Report.

A 19-year-old Japanese male recipient, who received a living related kidney transplantation from his father at 5 years old, was hospitalized for second renal transplantation from a cadaveric donor. The recipient had had an antibody-mediated rejection (AMR) to the first transplanted kidney. HLA typing of A, B, and DRB showed 2 of 6 mismatches. Lymphocyte cytotoxicity test (LCT) and flow cytometry crossmatches (FCXM) were negative on T cells. Tacrolimus, mycophenolate mofetil, methylprednisolone, and basiliximab induction were used as the standard immunosuppressive therapy. After second renal transplantation, his serum creatinine level favorably decreased until postoperative day (POD) 7, but his serum creatinine level raised from POD 8. We performed steroid pulse and intravenous immunoglobulin (IVIG). The episode biopsy showed AMR although FCXM and LCT were still negative on T cell. To determine the cause of AMR, we examined LABScreen single antigen test (One Lambda, Canoga Park, Calif., United States), and there was a donor-specific antibody (DSA) that is DQB8 in pre- and post-second renal transplantation. The DSA was suspected de novo DSA for the first transplanted kidney. AMR was successfully treated with plasma exchange, IVIG, and rituximab.

Antibody-Mediated Rejection Due to Donor-Specific HLA-DQB1 and DQA1 Antibodies After Kidney Transplantation: A Case Report.

BACKGROUND: Donor-specific HLA antibody (DSA) is associated with the risk of allograft loss due to antibody-mediated rejection (ABMR). The majority of de novo DSA after kidney transplantation is directed toward donor HLA-DQ antigens. A HLA-DQ antigen is a heterodimer consisting of an alpha and beta chain. Traditionally, HLA-DQA1 typing has not been part of the pretransplant evaluation. Therefore, DQ alpha proteins are not usually taken into account in the interpretation of HLA-DQ antibody reactions. METHODS: We hereby present a case of a kidney transplant recipient with 0% pretransplant panel reactive antibody. She received kidney allograft from her husband. Two years after transplantation, she experienced abdominal swelling, and enlargement of transplanted kidney was identified. A biopsy of the allograft kidney demonstrated chronic active ABMR. DSAs were investigated using immunoglobulin G (IgG) and C1q single antigen bead (SAB) assay. HLAMatchmaker analysis was performed to identify eplets that explain the antibody reactivity patterns. RESULTS: The IgG SAB analysis of a patient's serum at the time of rejection showed positive reactions with all DQ2-carrying beads with mean fluorescence intensity (MFI) > 10000. However, the C1q assay demonstrated strong reaction to only HLA-DQA1∗05:01-DQB1∗02:01-carrying bead with MFI = 22462, whereas weak or no reactions against other HLA-DQ2-carrying beads were found. High-resolution HLA typing revealed that HLA-DQA1∗05:01 and DQB1∗02:01 were mismatched donor antigens. HLAMatchmaker analysis showed that the antibodies were reactive toward 40GR3 eplet on DQA1 and 45GE3 eplet on DQB1. CONCLUSIONS: This case highlights the clinical significance of antibodies specific to both DQ alpha and DQ beta chains after kidney transplantation.

Dipeptidyl peptidase-4 inhibitor-associated bullous pemphigoid, likely triggered by scabies, in a hemodialysis patient with human leukocyte antigen-DQB1*03:01.

Bullous pemphigoid (BP) is the most common autoimmune subepidermal bullous diseases. Autoantibodies against hemidesmosomal adhesion proteins might be involved in the developing process. BP usually affects the elderly with high mortality whereas the drug-induced BP is often improved and rarely relapses after the withdrawal of the suspected drug. An accumulated evidence suggests that dipeptidyl peptidase-4 inhibitor (DPP-4I), which has been widely used as the antidiabetic drug improves glycemic control with little risk for hypoglycemia, could be an inducer of DPP-4I-associated BP (DPP-4I-BP). While the precise mechanism remains unclear, a unique immunological profile with human leukocyte antigen (HLA)-DQB1*03:01 could be a biomarker of genetic susceptibility to DPP-4I-BP. Here, we encountered an interesting case of DPP-4I-BP with HLA-DQB1*03:01, which was likely triggered by scabies. A 56-year-old Japanese male with type 2 diabetes on hemodialysis was referred to our hospital due to worsened blisters. Prior to his admission, he had been on linagliptin, a DPP-4I, for 5 months. He then suffered from scabies 2 weeks before his admission while the treatment with ivermectin failed to improve his symptom. Based on his clinical symptom, positive for anti-BP180 autoantibody in serum, and the pathological alterations of skin biopsy specimens, he was diagnosed with DPP-4I-BP. Importantly, he also carried an HLA-DQB1*03:01 allele. Oral prednisolone was subsequently administered after the discontinuation of linagliptin, and his symptom gradually disappeared. Given the fact that the DPP-4I-BP could be a life-threating disease, we should be cautious of prescribing DPP-4I in hemodialysis patients, whose immune system could be impaired.

The olfactory bulb: A link between environmental agents and narcolepsy, from the standpoint of autoimmune etiology.

Narcolepsy type 1 is a lifelong sleep disorder characterized by the loss of hypocretin-producing neurons in the brain. Environmental agents, including influenza, neurotoxic metals, and combustion smoke, have been implicated in the pathogenesis, especially in carriers of the human leukocyte antigen class II DQB1*06:02 allele. Sensitive experimental approaches have recently revealed hypocretin-autoreactive CD4+ and CD8+ T cells in the blood of narcoleptic patients. However, such potentially harmful cells are also detectable, to a lesser degree, in control DQB1*06:02 carriers, suggesting that the integrity of the blood-brain barrier (BBB) provides a neuroprotective effect. Here, we present the hypothesis that external toxic agents induce neuroinflammation in the olfactory bulb and concomitant overproduction of proinflammatory cytokines (e.g., tumor necrosis factor-α and interferon-γ); this, in turn, compromises the BBB, allowing autoimmune cells to access and kill hypocretinergic neurons. Such sequential pathological alterations could occur insidiously, passing unnoticed and consequently being underestimated. The elevated number of autoreactive T cells in narcoleptics relative to controls might reflect externally induced immunomodulation rather than a direct disease trigger.

Circulating follicular helper T cells exhibit reduced ICOS expression and impaired function in narcolepsy type 1 patients.

Despite genetic and epidemiological evidence strongly supporting an autoimmune basis for narcolepsy type 1, the mechanisms involved have remained largely unknown. Here, we aimed to investigate whether the frequency and function of circulating follicular helper and follicular regulatory T cells are altered in narcolepsy type 1. Peripheral blood mononuclear cells were collected from 32 patients with narcolepsy type 1, including 11 who developed disease after Pandemrix® vaccination, and 32 age-, sex-, and HLA-DQB1*06:02-matched healthy individuals. The frequency and phenotype of the different circulating B cell and follicular T cell subsets were examined by flow cytometry. The function of follicular helper T cells was evaluated by assessing the differentiation of naïve and memory B cells in a co-culture assay. We revealed a notable increase in the frequency of circulating B cells and CD4+CXCR5+ follicular T cells in narcolepsy patients compared to age-, sex- and HLA-matched healthy controls. However, the inducible T-cell costimulator molecule, ICOS, was selectively down-regulated on follicular T cells from patients. Reduced frequency of activated ICOS+ and PD1high blood follicular T cells was also observed in the narcolepsy group. Importantly, follicular T cells isolated from patients with narcolepsy type 1 had a reduced capacity to drive the proliferation/survival and differentiation of memory B cells. Our results provide novel insights into the potential involvement of T cell-dependent B cell responses in the pathogenesis of narcolepsy type 1 in which down-regulation of ICOS expression on follicular helper T cells correlates with their reduced function. We hypothesize that these changes contribute to regulation of the deleterious autoimmune process after disease onset.

New DQA1 allele specific antibody against epitope 2D (an exon 1 encoded amino acid). Considerations for alleles under the same P-group designation.

The majority of polymorphisms of the Human Leukocyte Antigen (HLA) proteins are clustered at the peptide binding domain (PBD), defined as the area coded by exon 2 and 3 for class I and exon 2 for class II. HLA alleles with the same amino acid (AA) sequence at the PBD are considered functionally equivalent and can be grouped under the same P-group designation. Here we present a case of a kidney recipient, typed as DQA1*01:04, 01:05 and DQB1*05:01P, 05:03, who developed antibodies against all DQ antigens on our Luminex Single Antigen (LSA) panel. Our LSA panel does not include DQA1*01:05 or 01:04, but both alleles belong to the DQA1*01:01P group and beads carrying DQA1*01:01 tested positive. Mature protein sequence alignment demonstrated a single AA mismatch between DQA1*01:04/01:05 and DQA1*01:01 located at position 2 (G vs D), which is encoded by exon 1. Luminex assay by another manufacturer which include a bead carrying patient's own DQA1* type and crossmatch studies with surrogate donors confirmed the presence of an antibody against mismatched epitope 2D. This case illustrates that alleles included in the same P-group may have polymorphisms able to trigger immunological responses and brings attention to the fact that some mature HLA proteins express AA encoded by exon 1, which is structurally part of the PBD.

Novel minor HLA DR associated antigens in type 1 diabetes.

Type 1 diabetes is an autoimmune disease leading to insulin deficiency. Autoantibodies to beta cell proteins are already present in the asymptomatic phase of type 1 diabetes. Recent findings have suggested a number of additional minor autoantigens in patients with type 1 diabetes. We have established luciferase immunoprecipitation systems (LIPS) for anti-MTIF3, anti-PPIL2, anti-NUP50 and anti-MLH1 and analyzed samples from 500 patients with type 1 diabetes at onset of clinical disease and 200 healthy individuals who had a family history of type 1 diabetes but no evidence of beta cell autoantibodies. We show significantly higher frequencies of anti-MTIF3, anti-PPIL2 and anti-MLH1 in recent onset type 1 diabetes patients in comparison to controls. In addition, antibodies to NUP50 were associated with HLA-DRB1*03 and antibodies to MLH1 were associated with HLA-DRB1*04 genotypes.

Genetic association of HLA-DRB1 multiple polymorphisms with dermatomyositis in Chinese population.

Genetic variation in HLA plays an important role in the pathogenesis of dermatomyositis (DM). The aim of this study was to investigate the association of HLA class II with DM in China. Two hundred and twenty-four DM patients and 300 healthy controls were randomly enrolled at China-Japan Friendship Hospital. High-resolution typing of HLA-DRB1 alleles was performed by sequencing based typing. The HLA-DQA1 and HLA-DQB1 alleles were determined by polymerase chain reaction sequence-specific primers. The frequencies of HLA-DRB1*09:01 (28.6% vs 11.3%, P < .0001, odds ratio, OR = 3.14, 95% confidence interval, CI = 2.47-3.99) and HLA-DRB1*12:01 (29.0% vs 11.0%, P < .0001, OR = 3.30, 95% CI = 2.59-4.20) in DM patients were significantly higher than that in healthy controls. No significant difference was found in HLA-DQA1 or DQB1 alleles between DM patients and healthy controls. Furthermore, DM patients with anti-melanoma differentiation-associated gene 5 antibody (anti-MDA5) had a significantly higher frequency of HLA-DRB1*12:01 compared to that for patients without anti-MDA5 (P < .0001, OR = 4.77, 95% CI: 2.29-9.93). Multivariate binary logistic regression analysis was performed to identify the risk factors for interstitial lung disease. The HLA-DRB1*09:01 allele was a poor prognostic factor (P = .01, OR = 9.21, 95% CI: 1.47-57.50) for DM patients with anti-MDA5 autoantibody. In summary, our findings indicate that HLA-DRB1*09:01 and HLA-DRB1*12:01 alleles may contribute to susceptibility of adult DM in Han Chinese population. In addition, the DRB1*12:01 genotype is significantly associated with the presence of anti-MDA5 antibody in DM patients.

Characterization of the novel HLA-DQB1*05:155 allele by sequencing-based typing.

HLA-DQB1*05:155 differs from HLA-DQB1*05:01:01 by one nucleotide substitution at position 474 (G>C).

A novel HLA class II allele, HLA-DQB1*03:73.

The HLA-DQB1*03:73 allele differs from DQB1*03:01:01:01 by 1 nucleotide substitution at position 209.

Identification of the HLA-DQB1*06:123 allele in an unrelated stem cell donor from the Saudi Registry.

HLA-DQB1*06:123 differs from HLA-DQB1*06:29 by six nucleotide substitutions resulting in five amino acid changes.

HLA-DRB1*07:01-HLA-DQA1*02:01-HLA-DQB1*02:02 haplotype is associated with a high risk of asparaginase hypersensitivity in acute lymphoblastic leukemia.

Hypersensitivity reactions are the most frequent dose-limiting adverse reactions to Escherichia coli-derived asparaginase in pediatric acute lymphoblastic leukemia (ALL) patients. The aim of the present study was to identify associations between sequence-based Human Leukocyte Antigen Class II region alleles and asparaginase hypersensitivity in a Hungarian ALL population. Four-digit typing of HLA-DRB1 and HLA-DQB1 loci was performed in 359 pediatric ALL patients by using next-generation sequencing method. Based on genotypic data of the two loci, haplotype reconstruction was carried out. In order to investigate the possible role of the HLA-DQ complex, the HLA-DQA1 alleles were also inferred. Multivariate logistic regression analysis and a Bayesian network-based approach were applied to identify relevant genetic risk factors of asparaginase hypersensitivity. Patients with HLA-DRB1*07:01 and HLA-DQB1*02:02 alleles had significantly higher risk of developing asparaginase hypersensitivity compared to non-carriers [P=4.56×10-5; OR=2.86 (1.73-4.75) and P=1.85×10-4; OR=2.99 (1.68-5.31); n=359, respectively]. After haplotype reconstruction, the HLA-DRB1*07:01-HLA-DQB1*02:02 haplotype was associated with an increased risk. After inferring the HLA-DQA1 alleles the HLA-DRB1*07:01-HLA-DQA1*02:01-HLA-DQB1*02:02 haplotype was associated with the highest risk of asparaginase hypersensitivity [P=1.22×10-5; OR=5.00 (2.43-10.29); n=257]. Significantly fewer T-cell ALL patients carried the HLA-DQB1*02:02 allele and the associated haplotype than did pre-B-cell ALL patients (6.5%; vs. 19.2%, respectively; P=0.047). In conclusion, we identified a haplotype in the Human Leukocyte Antigen Class II region associated with a higher risk of asparaginase hypersensitivity. Our results confirm that variations in HLA-D region might influence the development of asparaginase hypersensitivity.

Three new HLA alleles-B*49:43, C*03:321 and DQB1*02:72.

Immunogenetic information is provided on 3 novel HLA-B, -C and -DQB1 alleles.

A dispermic chimerism detected in a Taiwanese potential unrelated hematopoietic stem cell donor.

Chimerism is defined as the presence of 2 or more than 1 genetically distinct cell populations in an organism. Dispermic chimeras are derived from the fertilization of 1 or 2 matured nuclei by 2 sperms. We here report detection of a healthy and phenotypically normal female with normal ABO red blood cell typing in whom dispermic chimerism was suspected after 3 alleles were identified at multiple human leukocyte antigen (HLA) loci using molecular HLA analysis. Molecular HLA typing showed the donor to have 3 HLA-A, -B, -C, -DRB1, -DQB1 and -DPB1 alleles in blood, saliva and nail samples. In addition, 3 of her 9 short tandem repeat loci also showed to have 3 distinct alleles in blood, nail and saliva specimens. In all investigations, the third alleles were attributed to a dual paternal contribution. This case represents a dispermic chimerism, with 2 paternal and 1 maternal haplotypes variably distributed throughout body tissues in a healthy and phenotypically normal female without abnormalities in erythrocyte ABO blood group. The origin of this chimerism is probably due to the fertilization of a single egg and its polar body, or a parthenogenetic egg, by 2 sperms.

Identification of two novel HLA-DQB1 alleles, HLA-DQB1*03:164 and HLA-DQB1*03:165 in Chinese individuals.

HLA-DQB1*03:164 shows 604G>T and HLA-DQB1*03:165 has 611 C>G change compared with HLA-DQB1*03:01:01:01.

Intravascular large B-cell lymphoma associated with silicone breast implant, HLA-DRB1*11:01, and HLA-DQB1*03:01 manifesting as macrophage activation syndrome and with severe neurological symptoms: a case report.

BACKGROUND: Silicone implants have been successfully used for breast augmentation and reconstruction in millions of women worldwide. The reaction to the silicone implant is highly variable; it can lead to local inflammatory symptoms, and sometimes to systemic symptoms and disease. Over 80 cases of anaplastic lymphoma kinase-negative anaplastic large cell lymphoma have been reported in patients with silicone breast implants and have been accepted as a new clinical entity. To the best of our knowledge, an intravascular large B-cell lymphoma associated with a silicone breast implant has not been reported previously. CASE PRESENTATION: A 48-year-old Caucasian woman who presented with high fever was found to have splenomegaly on physical examination. A laboratory diagnosis revealed pancytopenia, hypertriglyceridemia, and hyperferritinemia. She developed signs of altered sensorium, hemiparesis, aphasia, and cauda equina syndrome. On further evaluation, she fulfilled the necessary five out of eight criteria for diagnosis of macrophage activation syndrome/hemophagocytic lymphohistiocytosis. Dexamethasone administration was followed by prompt improvement; however, 3 days later she again manifested high fever, which persisted despite administration of immunoglobulin and cyclosporine A. Her silicone breast implant was considered a possible contributor to her macrophage activation syndrome and was therefore removed. A histological examination of the capsule tissue showed an extensive lymphohistiocytic/giant cell foreign body reaction suggestive of autoimmune/inflammatory syndrome induced by adjuvants. However, the histological examination unexpectedly also revealed an intravascular large B-cell lymphoma. CONCLUSIONS: The genetic background of our patient with silicone breast implants might have predisposed her to three rare and difficult to diagnose syndromes/diseases: macrophage activation syndrome/hemophagocytic lymphohistiocytosis, autoimmune/inflammatory syndrome induced by adjuvants, and intravascular large B-cell lymphoma. The simultaneous manifestation of all three syndromes suggests causal interrelationships. Human leukocyte antigen testing in all women who undergo silicon breast implantation could in the future enable us to better evaluate the risk of potential side effects.

Five new HLA alleles with synonymous mutations: A*01:01:65, A*01:01:66, B*44:03:35, DRB1*15:01:30 and DQB1*02:01:24.

Immunogenetic information is provided on five novel alleles with synonymous mutations.

[HLA DRB1*, DQB1*, DPA1*, and DPB1* and their association with the pathogenesis of leukemia in the population of Venezuela]. / HLA DRB1*, DQB1*, DPA1* y DPB1* y su asociación con la patogénesis de las leucemias en población venezolana.

BACKGROUND: The HLA complex involved is a factor in the pathogenesis of leukemia. OBJECTIVES: The presence of class II HLA alleles DRB1 *, DQB1 *, DPA1 *, and DPB1 * was evaluated in 47 patients with acute lymphoblastic leukemia (ALL) and 48 with chronic myeloid leukemia (CML) for comparison with 48 healthy volunteers in Zulia, Venezuela, and to evaluate potential associations of HLA with leukemia. METHODS: Low- and high-resolution PCR-SSP was used for class II HLA regions DRB1 *, DQB1 *, DPA1 *, and DPB1 * following the instructions of KIT Olerup SSP Genovision. RESULTS: Alleles HLA-DRB1*14, especially DRB1*14:21, -DPA1*1:06, -DPA1*01:03,-DPA1*02:01, and the haplotypes HLA-DPA1*01:03-DPB1*04:01, DPA1*01:03-DPB1*02:01, DPA1*01:03-DPB1*99:01, -DRB1*14-DPA1*01:03, -DRB1*15-DPA1*01:03 were associated with CML (RR > 3); alleles HLA-DRB1*13, -DQB1*02, -DPA1*01:05, -DPA1*01:09 and the haplotypes HLA-DPA1*01:09-DPB1*02:01, DPA1*01:09-DPB1*04:01 were protective (RR < 1). Alleles HLA-DQB1*04, -DQB1*05, -DPA1*1:06, -DPA1*01:07, -DPA1*1:08 had a positive association with ALL. Alleles HLA-DPA1*01:09, -DPA1*02:01, -DPB1*02:01, -DPB1*03:01 and the haplotypes HLA-DPA1*01:03-DPB1*04:02, -DPA1*01:09-DPB1*02:01, -DPA1*01:09-DPB1*04:01, -DPA1*02:01-DPB1*04:02 were negatively associated. CONCLUSIONS: The other association patterns identified suggest marked differences in the pathogenesis of leukemia, which suggests possible deficiencies in antigen presentation for ALL or potential effects of molecular mimicry in CML.

Antecedentes: La presencia de HLA es un factor que influye en la patogénesis de las leucemias. Objetivos: Se evaluó la presencia de alelos HLA clase II DRB1*, DQB1*, DPA1* y DPB1* en 47 pacientes con leucemia linfoide aguda (LLA) y 48 con leucemia mieloide crónica (LMC), para compararlos con 48 voluntarios sanos de Zulia, Venezuela, y determinar las posibles asociaciones de HLA con las leucemias. Métodos: Se utilizó la técnica de PCR-SSP de baja y alta resolución para las regiones HLA clase II DRB1*, DQB1*, DPA1* y DPB1* conforme las instrucciones del KIT Olerup SSP Genovision. Resultados: Los alelos HLA-DRB1*14, especialmente DRB1*14:21, -DPA1*1:06, -DPA1*01:03,-DPA1*02:01, y los haplotipos HLA-DPA1*01:03-DPB1*04:01, DPA1*01:03-DPB1*02:01, DPA1*01:03-DPB1*99:01, -DRB1*14-DPA1*01:03, -DRB1*15-DPA1*01:03 tuvieron asociación con LMC (RR > 3); los alelos HLA-DRB1*13, -DQB1*02, -DPA1*01:05, -DPA1*01:09 y los haplotipos HLA-DPA1*01:09-DPB1*02:01, DPA1*01:09-DPB1*04:01 resultaron protectores (RR < 1). Los alelos HLA-DQB1*04, -DQB1*05, -DPA1*1:06, -DPA1*01:07, -DPA1*1:08 tuvieron asociación positiva con LLA. Los alelos HLA-DPA1*01:09, -DPA1*02:01, -DPB1*02:01, -DPB1*03:01 y los haplotipos HLA-DPA1*01:03-DPB1*04:02, -DPA1*01:09-DPB1*02:01, -DPA1*01:09-DPB1*04:01, -DPA1*02:01-DPB1*04:02 resultaron asociados negativamente. Conclusiones: La fuerte asociación de HLA DRB1*14 con la LMC y la ausencia de asociaciones DRB1* con LLA y los otros patrones de asociación identificados sugieren marcadas diferencias en las patogénesis de las leucemias, lo que orienta hacia posibles deficiencias en la presentación antigénica para LLA o posibles efectos de mimetismo molecular en LMC.