Proteína-C reativa como biomarcador no diagnóstico precoce de infecção bacteriana na pessoa idosa

INTRODUCAO: A proteina C reativa (PCR) para o diagnostico de infeccao bacteriana na populacao idosa nao esta bem estabelecida. O objetivo deste estudo foi avaliar a importância da Proteina C reativa como biomarcador no diagnostico precoce de infeccoes bacterianas em pessoas idosas. METODOS: Foram avaliados idosos internados no Hospital Santa Casa de Misericordia de Vitoria-ES em um periodo de seis meses. Os niveis de PCR foram medidos em ate 48 horas de internacao e sua importância na predicao de infeccoes bacterianas foi analisada. RESULTADOS: Incluimos para analise 141 individuos, sendo 50,4% (71) do sexo feminino, com 77±9 (60-97) anos de idade, 78 (55,3%) sem infeccao, 36 (25,5%) infeccao estabelecida por criterios clinicos e microbiologicos e 27 (19,1%) com diagnostico provavel com evidencia radiologica, totalizando 63 pacientes (44,7%) com infeccao. Dentre as causas nao infecciosas, as mais frequentes foram insuficiencia cardiaca (24,3%), acidente vascular cerebral (6,41%), cirrose hepatica (6,76%), e nas infecciosas 44,4% pneumonia, 12,69% sepse e 7,92% infeccao urinaria. A proteina C reativa apresentou-se com ponto de corte em 49,20mg/L com sensibilidade de 68,3% e especificidade de 69,07% em area da curva de ROC 0,758 (0,67-0,83; p=0,001). CONCLUSAO: A elevacao da proteina C reativa , com ponto de corte ≥49,20mg/L, em pacientes analisados em ate 48 horas de admissao hospitalar, mostrou-se um bom preditor de infeccao bacteriana em idosos, dentro de um contexto clinico, visto que neste grupo populacional as manifestacoes clinicas de infeccoes sao frequentemente atipicas. BACKGROUND AND OBJECTIVE: The C-reactive protein (CRP) for the diagnosis of bacterial infection in the elderly population is not well established. The objective of this study was to evaluate the importance of C-reactive Protein as a biomarker in the early diagnosis of bacterial infections in elderly people. METHODS: Elderly patients hospitalized in the Santa Casa de Misericordia Hospital in Vitoria-ES on a six-month period were evaluated. C-reactive protein P levels were measured within 48 hours of admission and its importance in predicting bacterial infections was analyzed. RESULTS: We included 141 individuals for analysis, with 50.4% (71) were female, with 77±9 (60-97) years, 78 (55.3%) without infection, 36 (25.5%) infection established by clinical and microbiological criteria and 27 (19.1%) with probable diagnosis with radiological evidence, totaling 63 patients (44.7%) with infection. Among the non-infectious causes, the most frequent was heart failure (24.3%), stroke (6.41%), liver cirrhosis (6.76%) and, among the infectious causes 44.4% pneumonia, 12.69% sepsis, and 7.92% urinary tract infection. The C-reactive protein presented with the cutoff point at 49.20mg/L with a sensitivity of 68.3% and specificity of 69.07% in area of the ROC curve 0.758 (0,67-0,83; p=0,001). CONCLUSION: Elevated C-reactive protein, with a cutoff ≥49.20mg/L in patients examined within 48 hours of hospital admission, proved to be a good predictor of bacterial infection in the elderly, within a clinical context, since clinical manifestations of infection are often a typical in this population group.