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Immunogenetic host factors are associated with susceptibility or protection to tuberculosis (TB). Strong associations of HLA class II genes with TB are reported. We analyzed the HLA-DRB1*04 alleles to identify subtypes associated with pulmonary TB and their interaction with risk factors such as alcohol, smoking, and gender in 316 pulmonary TB patients and 306 healthy individuals from the Brazilian Amazon. The HLA-DRB1*04 was prevalent in patients with pulmonary TB (p<0.0001; OR = 2.94; 95% CI = 2.12 to 4.08). Direct nucleotide sequencing of DRB1 exon 2 identified nine subtypes of HLA-DRB1*04. The subtype HLA-DRB1*04:11:01 (p = 0.0019; OR = 2.23; 95% CI = 1.34 to 3.70) was associated with susceptibility to pulmonary TB while DRB1*04:07:01 (p<0.0001; OR = 0.02; 95% CI = 0.001 to 0.33) to protection. Notably, the interaction between alcohol and HLA-DRB1*04:11:01 increased the risk for developing pulmonary TB (p = 0.0001; OR = 51.3; 95% CI = 6.81 to 386). Multibacillary pulmonary TB, the clinical presentation of disease transmission, was strongly associated with interaction to alcohol (p = 0.0026; OR = 11.1; 95% CI = 3.99 to 30.9), HLA-DRB1*04:11:01 (p = 0.0442; OR = 2.01; 95% CI = 1.03 to 3.93) and DRB1*04:92 (p = 0.0112; OR = 8.62; 95% CI = 1.63 to 45.5). These results show that HLA-DRB1*04 are associated with pulmonary TB. Interestingly, three subtypes, DRB1*04:07:01, DRB1*04:11:01 and DRB1*04:92 of the HLA-DRB1*04 could be potential immunogenetic markers that may help to explain mechanisms involved in disease development.

Seeking to improve the laboratory diagnosis of Cutaneous Tuberculosis, a study was carried out on the application of PCR technique in macerated, decontaminated (with 4% H2SO4 for elimination of normal microbiot), neutralized (with 4% NaOH) biopsies tissues samples stored at -20ºC. Of the 37 samples submitted for study, 16.22% were positive by microscopy for acid-fast bacilli (concentrated method) and in 43.24% the Mycobacterium tuberculosis was isolated in Löwenstein-Jensen medium. Using a M. tuberculosis complex specific primer set (gene sequence for 16S rDNA), the mycobacterial DNA was detected in 24.32% of the biopsies. The sensitivity and specificity of PCR were 43.7% and 90.4%, respectively. Due to low sensitivity and discrepant results between bacteriological techniques and PCR methodology, the samples were repeated in a new PCR with primers for the IS6110 target. The sensitivity and specificity of PCR for the IS6110 target obtained 100% in comparison with the culture method. The results confirm the effectiveness of PCR methodology using primers for the IS6110 gene sequence and permit the PCR method to be applied to frozen cutaneous biopsies sent by services that do not identify the M. tuberculosis by the biology molecular method.

Vaccines with synthetic peptides induce the immune response to epitopes that bind to several HLA alleles. By using a TEPITOPE algorithm, we selected and analyzed the T-cell responses of peripheral blood mononuclear cells from 29 paracoccidioidomycosis (PCM) patients to peptides of the immunodominant gp43 antigen of Paracoccidioides brasiliensis, the causative agent of PCM. Paracoccidioidomycosis (PCM) is caused by the fungusParacoccidioides brasiliensis and is the prevalent human systemic mycosis in Latin America (4,14,19,20). Current chemotherapy for the treatment of PCM is usually successful, although the treatment regimens are very long and relapses are frequent. Patients with chronic PCM would greatly benefit from a specific and active immunotherapy that could shorten the treatment period, increase the efficiency of chemotherapy, and protect against the relapse of disease.The immunodominant 43-kDa glycoprotein 43 (gp43) is the major diagnostic antigen for P. brasiliensis infection (17, 18; reviewed in reference 23) because it is recognized in virtually all sera from infected patients with active PCM, using different serological methods (6, 21). Although gp43 may be a virulence factor under some experimental conditions involving cell adhesion (9, 24) and PCM patients have blood circulating gp43 (12, 16), this antigen elicits a protective cellular immune response in mice of different haplotypes. Epitope mapping of the entire gp43 protein in the murine model identified the 15-mer peptide at positions 181 to 195, named P10, as the carrier of the immunodominant epitope in lymphocyte proliferation assays. The immunization of mice with either purified gp43 or P10 peptide was protective against subsequent intratracheal challenge with virulent P. brasiliensis agents (22), and use of P10 as an adjuvant to chemotherapy shortened the period of treatment and protected against relapsing disease (13). Additionally, previous data from our group identified, with the aid of the TEPITOPE algorithm that predicts binding to 25 different HLA-DR molecules (2, 3), the P10-analogous peptide gp43 at sequence positions 180 to 194 [gp43(180-194)] as the immunodominant peptide recognized by up to 53% of the peripheral blood mononuclear cells (PBMC) from 19 treated PCM patients (10). In this work, we extended the data previously reported by testing the previously selected peptides with PBMC from 10 additional PCM patients and 13 healthy donor individuals to evaluate specificity. All PCM patients were typed for HLA class II (Fig. 1, HLA distribution), and the observation that a great diversity of HLA-DR molecules is associated with the recognition of each peptide (Table 1) confirms the absence of a correlation of the disease with the HLA molecule (7), suggesting that peptides predicted to bind promiscuously were able to be presented by multiple HLA-DR molecules. Additionally, the frequency of allelic variation in the distribution of the HLA-DRs of the tested patients is similar to that of the Brazilian population spectra, so that the la...

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