Silvia Barbosa Dutra Marques

IL2 and TNFA Gene Polymorphisms and the Risk of Graft-versus-Host Disease after Allogeneic Haematopoietic Stem Cell Transplantation

This study aimed to analyse the association of gene polymorphisms with the outcome of allogeneic haematopoietic stem cell transplantation. We studied 122 donor/recipient pairs who received HLA‐identical transplants from siblings at the Universidade Estadual de Campinas, Brazil, between June 1996 and June 2006. Donor/recipient alleles for TNFA−238 and IL2−330/+166 single‐nucleotide polymorphisms (SNP) were analysed by PCR‐SSP. No association was observed between the risk of acute graft‐versus‐host disease (GVHD) and these SNP. However, our findings suggest that the polymorphism of promoter gene TNFA−238GA is associated with the occurrence and severity of chronic GVHD. The probability of chronic GVHD in patients with GA genotype at position −238 of TNFA gene is 91.7% in contrast to 59.4% in patients with GG genotype (P = 0.038). In patients with donor GA genotype the probability of chronic GVHD is 90.8%, and 57.9% in patients with donor GG genotype (P = 0.038). The probability of extensive chronic GVHD in patients with TNFA−238GA is 91.7% compared with 46.3% in patients with TNFA−238GG (P = 0.0046). In patients with donor GA genotype at position −238 of the TNFA gene, it is 81.7%, compared with 44.5% in patients with donor GG genotype (P = 0.016). However, further studies with more patients are required to identify cytokine gene polymorphisms and their association with transplant‐related complication in Brazil, particularly due to ethnic background, the relatively low power of detection of genetic markers of this study, and the complexity of the MHC region.

Family-based association of HLA class II alleles and haplotypes with type I diabetes in Brazilians reveals some characteristics of a highly diversified population.

The association of HLA class II haplotypes with type I diabetes was analyzed in 56 Southeastern Brazilian families using affected family-based controls (AFBAC) method. DRB1-DQA1-DQB1 alleles were determined by polymerase chain reaction/sequence-specific primer genotyping. This study first revealed the great haplotype diversity of Brazilians (65 different haplotypes even with incomplete DRB1 subtyping), probably due to the admixture of Africans genes with European and Amerindian genes in this population. The results revealed increased frequencies of the DRB1*03-DQA1*0501-DQB1*02 and DRB1*0401-DQA1*03-DQB1*0302 haplotypes in the patient group The highest risk for type I diabetes was associated with the heterozygote DRB1*03/*04 genotype as largely reported, and DRB1*03/X and DRB1*04/Y genotypes conferred a significant, but much lower disease risk. Protection from type I diabetes revealed some peculiarities in Southeastern Brazilians: a lack of significant protecting effect of the DRB1*1501-DQA1*0102-DQB1*0602 haplotype, and an apparent protection conferred by the DRB1*13-DQB1*0301, DRB1*11-DQB1*0301, and DRB1*01-DQB1*0501 two-locus haplotypes. The risk to type I diabetes in the highly diversified Southeastern Brazilians evidenced specific information to the prediction of the disease in this region of the country.

Associação entre HLA e leucemia em uma população brasileira de etnia mista

OBJECTIVE: The main purpose of this study was to investigate the class I HLA antigens and class II HLA allele frequencies in 164 patients with leukemia: 35 patients with ALL (acute lymphoid leukemia), 50 with AML (acute myeloid leukemia) and 78 with CML (chronic myeloid leukemia). METHODS: The genotyping of class I HLA was performed by microlymphocytotoxicity and of class II by PCR-SSP (polymerase chain reaction - sequence specific of primers) (One Lambda, Canoga Park, CA, USA). RESULTS: In patients with LLA, frequencies of HLA-B45 and HLA-B56 were higher (P = 0.02; OR = 3.13; 95%IC = 0.94-10.44; P = 0.03; OR = 3.61; 95%IC = 0.47-27.64, respectively), than in controls. In patients with AML, the frequency of HLA-B7 (P = 0.01; OR = 2.41; 95%IC = 1.25-4.67) was higher than in controls. The presence of HLA-B45 (P= 0.01; OR = 3.29; 95%IC = 1.46-7.40), HLA-DRB1*04 (P = 0.002; OR = 2.17; 95%IC = 1.36-3.46) and HLA-DRB1*08 (P = 0.004; OR = 2.36; 95%IC = 1.34-4.16) was associated to increased risk of CML developing. CONCLUSION: Our results suggest that variants of HLA confer susceptibility to the same forms of leukemia, and could provide new tools for the investigation of genetics and etiology of this disease.

HLA Haplotypes and Genotypes Frequencies in Brazilian Chronic Periodontitis Patients

Human leukocyte antigens (HLA) have a pivotal role in immune response and may be involved in antigen recognition of periodontal pathogens. However, the associations of HLA with chronic periodontitis (CP) have not been previously studied in the Brazilian population. In an attempt to clarify the issue of genetic predisposition to CP, we examined the distribution of HLA alleles, genotypes, and haplotypes in patients from Southern Brazil. One hundred and eight CP patients and 151 healthy and unrelated controls with age-, gender-, and ethnicity-matched were HLA investigated by polymerase chain reaction with sequence specific oligonucleotides. To exclude smoking as a predisposing factor, statistical analyses were performed in the total sample and in nonsmoking individuals. The significant results showed a positive association of the A∗02/HLA-B∗40 haplotype with CP (total samples: 4.2% versus 0%, P c = 0.03; nonsmokers: 4.3% versus 0%, P c = 0.23) and a lower frequency of HLA-B∗15/HLA-DRB1∗11 haplotype in CP compared to controls (total samples: 0.0% versus 4.3%, P c = 0.04; nonsmokers: 0 versus 5.1%, P c = 1.0). In conclusion, the HLA-A∗02/B∗40 haplotype may contribute to the development of CP, while HLA-B∗15/DRB1∗11 haplotype might indicate resistance to disease among Brazilians.

The role of KIR2DL3/HLA-C*0802 in Brazilian patients with rheumatoid vasculitis

OBJECTIVES: Rheumatoid arthritis is a polygenically controlled systemic autoimmune disease. Rheumatoid vasculitis is an important extra-articular phenotype of rheumatoid arthritis that can result in deep cutaneous ulcers. The objective of this study was to establish a correlation between the frequency of major histocompatibility complex class I/II alleles and killer immunoglobulin-like receptor genotypes in patients with cutaneous rheumatoid vasculitis. METHODS: Using the Scott & Bacon 1984 criteria to diagnose rheumatoid vasculitis and after excluding any other causes such as diabetes, atherosclerosis, adverse drug reactions, infection, and smoking, patients who met the criteria were selected. All of the selected rheumatoid vasculitis patients presented deep cutaneous ulcers. Identification of the major histocompatibility complex class I/II and killer immunoglobulin-like receptor genotypes was performed by polymerase chain reaction assays of samples collected from the 23 rheumatoid vasculitis patients as well as from 80 controls (40 non-rheumatoid vasculitis RA control patients and 40 healthy volunteers). RESULTS: An association between the presence of the HLA-DRB1*1402 and HLA-DRB1*0101 alleles and cutaneous lesions in rheumatoid vasculitis patients and a correlation between the inhibitor KIR2DL3 and the HLA-C*0802 ligand in rheumatoid vasculitis patients were found. CONCLUSION: An association was found between the presence of the HLA-DRB1*1402 and HLA-DRB1*0101 alleles and the development of cutaneous lesions in rheumatoid vasculitis patients. Additionally, the HLA-C*0802 ligand protects these individuals from developing cutaneous lesions.

Correlation of IL-6 and IL-10 production following bone marrow transplantation with donor cytokine gene polymorphisms

Estudos de varios genes candidatos tem demonstrado que polimorfismos geneticos em genes de citocinas contribuem com variacoes nos niveis de citocinas produzidas e esta variacao pode influenciar a ocorrencia e gravidade de complicacoes apos o transplante de celulas-tronco hematopoeticas (TCTH). Neste trabalho comparamos as concentracoes sericas de TNF-α, IFN-γ, IL-6, IL-10 e TGF-β 1 em 13 receptores seguindo o TCTH com os polimorfismos TNF-308, IFNG+874, IL6-174, IL10-1082,-819,-592 e TGFB1+869,+915. Os niveis sericos de citocinas foram medidos usando-se kits comerciais de ELISA para TNF-α, IFN-γ, IL-6, IL-10 e TGF-β 1 (BioSource®, Nivelles, Belgium, Europe). Os genotipos de doadores/receptores para estes polimorfismos de citocinas foram analisados pela reacao em cadeia da polimerase com sequencias especificas de primer (PCR-SSP) com o kit Cytokine Genotyping Primers (One Lambda, Canoga Park, CA, USA). Encontramos correlacao entre os niveis de IL-6 e IL-10 seguindo o TCTH e os polimorfismos IL6-174 e IL10-1082,-819,-592, mas nao para outras citocinas investigadas neste estudo. Aqueles com genotipos relativos a baixa producao de IL-6 e IL-10 produziram mais baixos niveis destas citocinas que aqueles com genotipos relativos a producao alta e/ou intermediaria destas citocinas (P < 0,05).

Association between human leukocyte antigens and graft-versus-host disease occurrence after allogenic hematopoietic stem cell transplantation

CONTEXT AND OBJECTIVE Graft-versus-host disease (GVHD) is one of the complications following allogenic stem cell transplantation. This study investigated an association between human leukocyte antigen (HLA) and the occurrence of acute and chronic GVHD in patients who had received stem cell transplantations from HLA-identical siblings. DESIGN AND SETTING Retrospective study at Hematology and Hemotherapy Center, Universidade Estadual de Campinas (Unicamp). METHODS The participants were 176 patients whose first transplant was between 1997 and 2009. HLA genotyping was performed serologically and using the polymerase chain reaction with specific primer sequence. RESULTS Acute GVHD was positively associated with HLA-A10 (P = 0.0007), HLA-A26 (P = 0.002), B55 (P = 0.001), DRB1*15 (P = 0.0211) and DQB1*05 (P = 0.038), while HLA-B16 (P = 0.0333) was more frequent in patients without acute GVHD. Chronic GVHD was positively associated with HLA-A9 (P = 0.01) and A23 (P = 0.0292) and negatively with HLA-A2 (P = 0.0031) and B53 (P = 0.0116). HLA-B35 (P = 0.0373), B49 (P = 0.0155) and B55 (P = 0.0024) were higher in patients with acute GVHD grade 3 or above, than in other patients. In patients with extensive chronic GVHD, HLA-A9 (P = 0.0004), A24 (P = 0.0059) and A26 (P = 0.0411) were higher than in other patients, while HLA-A2 was lower (P = 0.0097). CONCLUSION This study suggests that HLA can influence the incidence and severity of acute and chronic GVHD. However, a study with a better design and more patients will be needed to confirm these results.