Associação entre marcadores genéticos (HLA) e o carreamento nasal de Staphylococcus aureus em pacientes renais

• Autor(a) principal: Santos, Rosiane Ribeiro dos
• Data de Publicação: 2012
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Estadual de Maringá (RI-UEM)
• Texto Completo: http://repositorio.uem.br:8080/jspui/handle/1/2008
• topic: Staphylococcus aureus; Pacientes renais; Carreamento nasal; Human Leucocyte Antigens (HLA); Haplótipos.; Staphylococcus aureus; Nasal carriage; HLA; Haplotypes; Renal patients; Brazil.; Ciências da Saúde; Medicina

The nasal carriage of Staphylococcus aureus is a complex, worldwide-present, multifactorial event, depending on variables, associated to the bacteria and the host, with serious repercussions on economy and health care. Even though the nasal carriage of S. aureus is asymptomatic, it has great clinic and epidemiological importance, being considered the major risk factor for the acquisition of endogenous infections. Infections are the second major death cause in patients suffering from chronic renal failure and S. aureus is the microorganism most commonly involved in the infectious morbidity and mortality in this group. Patients on dialysis and kidney-transplanted patients are particularly vulnerable to acquisition of infections, once they are constantly submitted to risk factors and to immunosuppression. The development of an infection is directly related to the individual immune system response. In this system, the molecules of the Major Histocompatibility Complex which, in humans is named Human Leukocyte Antigens (HLA System), provide a central role for a comprehensive understanding of associated mechanisms of disease resistance and susceptibility. The role of the HLA molecules in the pathogenesis of diseases has been investigated for several infectious and non-infectious diseases. However, little is known. The present study aimed to investigate the association between the HLA molecules, class I (HLA-A, -B, -C) and class II (HLA-DR, -DQ), of dialysis and kidney-transplanted patients, and the condition of the bacteria's nasal carrier or non-carrier. The population of this research consisted of 166 patients on dialysis and 70 kidney-transplanted patients. The identification of S. aureus isolated samples from the patients' nasal vestibules was performed by means of Gram-stain and Tube coagulase test. Genomic DNA was extracted from the buffy coat by means of Biopur method and the HLA molecules genotyping was performed by SSO-Luminex methodology. Among the 166 dialysis patients, 31.33% were nasal carriers of S. aureus while in 70 kidney-transplanted patients the nasal carriage rate was 52.86%. In our study, the nasal carriage of S. aureus did not differ for gender, ethnicity, age, and duration of dialysis or transplantation, in both patient groups. Our results suggest the involvement of some HLA alleles in the nasal carriage of S. aureus: in dialysis patients, the allele HLA-B*44 (p=0.0331; OR: 2.37; IC95%: 1.01- 5.60) tending to the susceptibility for nasal carriage and, in kidney-transplanted patients, the involvement of the allele HLA-DRB1*03 (p= 0.0052; OR: 11.2; IC95%: 1.55- 494.7) in the susceptibility and the alleles HLA-B*40 (p= 0.0263; OR: 8.66; IC95%: 1.04- 72.39) and HLA-C*03 (p=0.0307; OR: 3.85; IC95%: 1.09- 17.30) in the protection for the nasal carriage of bacteria. Still considering the transplanted patients, it was noticed that the haplotype HLA-DRB1*03, -DQA1*05, -DQB1*02 (p= 0.0074; OR: 11.85; IC95%: 1.42- 98.59) was the most significant for S. aureus nasal carriage susceptibility. This study could contribute for a better understanding of the mechanisms involved in the carriage of these bacteria, aiming at the development of prevention and control strategies.