RESUMO

In this study, we report for the first time HLA allele and haplotype frequencies in the modern Panamanian population at a two-field (four digits) resolution level. Reported frequencies were calculated from genotype data for the HLA-A, -B, -C, -DPB1, -DQB1 and -DRB1 loci of 462 healthy unrelated Panamanian adults of Hispanic ethnicity. In addition to providing new insights on the allelic structure of the Panamanian population and its origin, these data are critical for better planning of healthcare strategies in the country and for future research exploring the association with certain chronic and infectious diseases.

Assuntos

RESUMO

The Mestizos of Oaxaca resulted from the admixture of Zapotecan Natives with Spaniards and Africans. We selected 112 donors from Oaxaca and applied next-generation sequencing to characterize exon and intron variants in complete or extended HLA genes. Some alleles found, are unique to Mexican Natives and most likely will be absent in most major ethnicities, namely: Caucasians, Africans or Asians. Among these are HLA-A*68:03:01, HLA-A*68:05:01, HLA-C*03:04:01:02, HLA-C*15:09, HLA-C*3:05, HLA-C*03:06:01, HLA-B*39:05:01, HLA-B*35:14:01, HLA-B*35:12:01, HLA-B*35:43:01, HLA-B*40:05, HLA-B:40:08, HLA-B*51:02:01, HLA-B*35:24:01 and HLA-B*39:08. HLA-DQA1*05:05:01:05 and some HLA-DRB1 alleles were only present in Amerindians/Mestizos. Three haplotypes are unique to Mexican Natives, five to Middle-Eastern and Sephardi-Jews. We detected a novel HLA-DQA1*04:01:01 exon 4 variant. Any novel allele may have been positively selected to enlarge the peptide-binding repertoire, and some, like HLA-B*39:02:02 and HLA-B*39:05:01 were found with unique haplotype associations, suggesting convergent evolution events and/or allele lineage diversification. The allele frequencies were fairly evenly distributed in most HLA loci with the exception of HLA-DPB1. The application of NGS in Oaxaca is novel and will lead to better use in the clinical setting. It offers deep knowledge on the population structure, origins, migration, and discovery of new alleles and haplotypes that other techniques did not achieve.

Assuntos

RESUMO

BACKGROUND: Geographic stomatitis is an uncommon oral lesion that presents similar clinical, histopathological and genetic features as those of psoriasis. These findings suggest that this lesion may actually represent an oral manifestation of psoriasis. We report one case of geographic stomatitis and discuss a possible connection between this condition and psoriasis. MAIN OBSERVATIONS: A 37-year-old woman presented with red patches, surrounded by a white border on the labial mucosa and a positive family history of psoriasis. Histopathological examination, immunohistochemical analysis with antibodies against CD4, CD8, CD20, CD68, CD31, and Ki-67 and HLA-A*, -B*, -C*, -DRB1*, -DQA1* and -DQB1* genotyping were performed. Histopathological examination revealed parakeratosis, marked elongation of rete ridges with acanthosis and clubbing, exocytosis, Munro microabscesses, pustule of Kogoj, dilated tortuous vessels at the tip of dermal papillae, and predominant superficial and perivascular lymphocytic chronic inflammatory cell infiltrate. Immunohistochemistry analysis revealed a predominant T-cell subepithelial infiltrate. Based on the referred clinicopathological findings and in the absence of cutaneous lesions, the diagnosis of geographic stomatitiswas confirmed. CONCLUSIONS: This case and theoretical data indicate that geographic stomatitis may be an oral manifestation of psoriasis. Moreover, to improve our understanding, psoriatic patients should routinely undergo a detailed oral examination and patients with geographic stomatitis should routinely be submitted to a cutaneous routine examination.

RESUMO

Hepatitis C virus (HCV) infection is a global medical problem. The current standard of treatment consists of the combination of peginterferon plus ribavirin. This regimen eradicates HCV in 55 percent of cases. The immune response to HCV is an important determinant of disease evolution and can be influenced by various host factors. HLA class II may play an important role in immune response against HCV. The objective of the present study was to determine the distribution of HLA class II (DRB1 and DQB1) alleles, their association with chronic HCV infection and their response to interferon therapy. One hundred and two unrelated white Brazilian patients with chronic HCV infection, 52 responders (45 males and 7 females) and 50 non-responders (43 males and 7 females) to antiviral treatment, were included in the study. Healthy Brazilian bone marrow donors of Caucasian origin from the same geographic area constituted the control group (HLA-DRB1, N = 99 and HLA-DQB1, N = 222 individuals). HLA class II genotyping was performed using a low-resolution DRB1, DQB1 sequence-specific primer amplification. There were higher frequencies of HLA-DRB1*13 (26.5 vs 14.1 percent) and HLA-DQB1*02 (52.9 vs 38.7 percent) in patients compared with controls; however, these were not significantly different after P correction (Pc = 0.39 and Pc = 0.082, respectively). There was no significant difference between the phenotypic frequencies of HLA-DRB1 (17.3 vs 14.0 percent) and HLA-DQB1 alleles in responder and non-responder HCV patients. The HLA-DRB1*07 allele was significantly more common in HCV patients (33.3 vs 12.1 percent) than in controls (Pc = 0.0039), suggesting that the HLA-DRB1*07 allele is associated with chronic HCV infection.

Assuntos