Alelos HLA-DR em pacientes com poliarterite nodosa e poliangite microscopica

O presente estudo avaliou a frequencia dos alelos HLA-DR em um grupo de 29 pacientes brasileiros caucasoides com PAN ou poliangiite microscopica e investigou uma possivel relacao entre os alelos HLA-DR, os indices de atividade e gravidade e as manifestacoes clinicas de doenca. O diagnostico de cada paciente baseou-se nos criterios do Colegio Americano de Reumatologia (ACR) para a PAN e da Conferencia Internacional de Consenso de Chapel Hill (CHCC) para poliangiite microscopica. A atividade e a gravidade da doenca foram mensuradas retrospectivamente, por ocasiao do diagnostico, utilizando-se, respectivamente, o Birmingham Vasculitis Activity Score (BVAS) e o Five-Factors Score (FFS). De acordo com o BVAS, os pacientes foram divididos em dois grupos: aqueles com BVAS The aim of this study was to evaluate the frequency and clinical associations of HLA-DR alleles in Brazilian Caucasian patients with polyarteritis nodosa (PAN) or microscopic polyangiitis (MPA). We evaluated 29 Caucasian patients with vasculitis classified as PAN or MPA according to the American College of Rheumatology (ACR) 1990 Criteria and Chapel Hill Consensus Conference (CHCC) nomenclature for vasculitis. HLA-DR alleles were typed using polymerase chain reaction-amplified DNA, hybridized with sequence specific low resolution primers. DNA obtained from 59 Caucasian healthy blood donors were used as control. In order to evaluate if a specific HLA may have influence on the clinical profile of those diseases, we also divided the patients according to Birmingham vasculitis score (BVAS) and Five-Factors Score (FFS) at the time of diagnosis. Increased frequency of HLA-DRB1*16 (p=0.023) and DRB4*01 (p=0.048) was found in patients with higher disease activity at the time of diagnosis (BVAS ³ 22). Patients with less severe disease (FFS=0) had a higher frequency of HLA-DRB1*03 (p=0.011). Patients with gastrointestinal tract involvement had significantly increased frequency of HLA-DRB1*11 or B1*12 (p=0.046), B1*13 (p=0.021) and B3 (p=0.008). In contrast, patients with renal disease, had higher frequency of DRB1*15 or DRB1*16 (p=0.035) and B5 (p=0.035). Our results suggest that HLA-DR alleles may influence PAN and MPA clinical expression and outcome.