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Background: Geographic tongue (GT) is the most frequent oral lesion in psoriatic patients (PP), and genetic involvement in these conditions has been described. The association of psoriasis with GT is still not clear, and the study of human leucocyte antigen (HLA) may help clarify this relation., Objective: The aim of this study was to investigate the association of HLA alleles with psoriasis vulgaris and GT., Methods: Fifty-eight Brazilian PP, 29 GT patients and 125 healthy controls individuals were selected. Information on demographic and clinical characteristics was collected. All patients underwent an oral examination and blood collection for HLA typing., Results: HLA-A did not show significant differences in frequencies among the groups. HLA-B*57 allele was more frequently found in PP and was not found in GT. HLA-B*58 allele was more frequently found in GT. HLA-C*06 and -C*18 alleles were associated with psoriasis. No significant differences in HLA-DRB1 and HLA-DQB1 were observed., Conclusion: HLA-B*58 was associated with GT and HLA-B*57 was possibly associated with psoriasis. This suggested that some GT cases may represent true oral psoriasis and some may represent only GT. Therefore, it is necessary to make this distinction and increase our sample size to improve the correct diagnosis and treatment of these conditions., (© 2014 European Academy of Dermatology and Venereology.)

Killer cell immunoglobulin-like receptors (KIR) are expressed mainly in natural killer cells and specifically recognize human leukocyte antigen (HLA) class I molecules. The repertoire of KIR genes and KIR-HLA pairs is known to play a key role in the susceptibilities to and the outcomes of several diseases, including malaria. The aim of this study was to investigate the distribution of KIR genes, KIR genotypes and KIR-HLA pair combinations in a population naturally exposed to malaria from Brazilian Amazon. All 16 KIR genes investigated were present in the studied population. Overall, 46 KIR genotypes were defined. The two most common genotypes in the Porto Velho communities, genotypes 1 and 2, were present at similar frequencies as in the Americas. Principal component analysis based on the frequencies of the KIR genes placed the Porto Velho population closer to the Venezuela Mestizos, USA California hispanic and Brazil Paraná Mixed in terms of KIR gene frequencies. This analysis highlights the multi-ethnic profile of the Porto Velho population. Most of the individuals were found to have at least one inhibitory KIR-HLA pair. Seventy-five KIR-HLA pair combinations were identified. The KIR-2DL2/3_HLA-C1, KIR3DL1_HLA-Bw4 and KIR2DL1_HLA-C2 pairs were the most common. There was no association between KIR genes, KIR genotypes or KIR-HLA pair combinations and malaria susceptibility in the studied population. This is the first report on the distribution of KIR and known HLA ligands in the Porto Velho population. Taken together, these results should provide baseline information that will be relevant to population evolutionary history, malaria and other diseases studies in populations of the Brazilian Amazon., (© 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Approximately 20% of hepatitis C virus (HCV) infected individuals clear the virus. Host factors that influence the course of HCV infection are still under investigation, and the data on the association of human leukocyte antigen (HLA) alleles and HCV clearance are scarce and controversial. The aims of this study were to investigate whether HLA alleles are associated with clearance of HCV infection in a highly admixed Brazilian population and whether these associations could be influenced by ethnicity and route of infection. HLA-A, -B, -C, -DRB1 and -DQB1 genotyping were performed in 135 HCV-infected Brazilian patients among which 45 cleared HCV infection (cases) and 90 had persistent viral infection (controls). Controls were matched by sex, ethnicity (withes and non-whites) and route of infection (high infectious dose or low infectious dose). No significant association was identified between HLA alleles and the outcome of HCV infection when analyzing the sample as a single group. However, a new protective association of HLA-DQB1*04 (P = 0.006; P(c) = 0.030) and a rarely described association of HLA-DRB1*08 (P = 0.004; P(c) = 0.048) were found only among white patients. The DRB1*11 allele, previously reported in homogeneous population, was associated with HCV clearance (P = 0.020) only among patients with expected high-dose exposure. These findings confirm the influence of ethnicity on the associations of HLA with spontaneous viral clearance of HCV infection and emphasize the possible influence of route of infection in this process., (© 2011 Blackwell Publishing Ltd.)

Background: Psoriasis vulgaris is a skin disease with a complex immunological and genetic background, triggered by environmental factors. The association of human leukocyte antigens (HLA) and psoriasis has long been reported on population and familial studies., Objectives: To review and discuss studies on psoriasis vulgaris and HLA, in Caucasian and non-Caucasian populations., Methods: The major population studies on psoriasis vulgaris and the associated HLA antigens and alleles are described and discussed based on a review of the current literature., Results: Population studies demonstrate the presence of different HLA specificities as well as extended haplotypes in patients with psoriasis, when compared to controls. Some alleles occur in a lower frequency in patients with psoriasis, indicating they could be protection alleles. In all studies which HLA class I was typed, Cw6 or Cw*0602 was present in a significant frequency in patients with psoriasis, mainly when early onset and positive family history were considered. HLA-DRB1*0701 was also present in a higher frequency in patients in different populations., Conclusions: Different antigens and alleles from both HLA classes I and II were seen in a significantly higher frequency in patients with psoriasis vulgaris. HLA Cw*0602 and DRB1*0701 were represented in different reports, and the former was related mainly to psoriasis type I.

Objectives: The human leucocyte antigen (HLA) has been related to susceptibility factors in several diseases. This study aimed to determine the potential genetic susceptibility of patients with pityriasis rosea (PR) through HLA molecular typing analysis., Methods: The method of choice was polymerase chain reaction with sequence-specific primers (PCR-SSP) using low-resolution typing kits, with determination of the alleles class I (HLA-A, HLA-B and HLA-C) and class II (HLA-DRB1, DRB3, DRB4, DRB5 and DQB1) performed in 30 Afro-Brazilian PR-diagnosed patients and 45 healthy individuals as the control group (PR-C)., Results: Analysis of the HLA typing results showed that the relative risk (RR) of 4.00 [95% confidence interval (95% CI) 1.20-13.28, two-tailed P = 0.018] for allele HLA-DQB1*04 class II, detected in 33.3% of PR patients, was significant. By contrast, in the control group only 11.1% of subjects had that allele. Three out of six B*51 alleles and three out of six B*53 alleles detected in PR patients were found, together with the allele DQB1*04., Conclusion: We suggest that alleles DQB1*04 may be involved in the genetic susceptibility of PR based on the significant predominance of those alleles observed in the black PR patients. We also recommend that more studies are conducted on populations of other ethnic origins, preferentially with higher resolution techniques of DNA typing.

Immunological rejection of kidney allografts is usually attributed to presensitization to HLA antigens. However, data on HLA identical transplant rejections indicate that non-HLA antigens may also be involved, and it has been suggested that vascular endothelium represents the main target cell. The purpose of the present study is to describe a method of detecting non-HLA antibodies immunocytochemically. We showed the molecular independence between HLA-ABC molecules identified by the monoclonal antibody w6/32, and antigenic sites identified by a kidney rejection patient serum, previously characterized, on cultured endothelial cells isolated from human umbilical cords by collagenase digestion. Single immunofluorescence staining indicated the molecular independence between these antigenic sites, as the first serum showed a granular pattern, diffused throughout the cytoplasm and the other a reticular pattern restricted to the same cytoplasmic region. This result was confirmed by double labeling. Immunoelectronmicroscopy study also confirmed site independence, showing labeling patterns with different intensities and distinct localizations, using 10- and 20-nm colloidal gold particles to reveal HLA-ABC and non-HLA-ABC determinants, respectively. In conclusion, cultured endothelial cells may be used immunocytochemically to detect non-HLA-ABC determinants of antibody reactivity in renal graft recipients, and the indirect immunofluorescence may be the methodology of choice, since it is easy, reliable and low cost.