Índice aspartato-aminotransferase/plaquetas (APRI) em pacientes com malária aguda por Plasmodium vivax

Abstract

Several pathophysiological changes may favor the severity of malaria and cause millions of deaths annually in the world. Metabolic and hematological disturbances are common complications when the causative agent is P. falciparum. P. vivax, classically associated with benign disease, has been presenting a serious and fatal evolution in recent years, mainly due to the biochemical and hematological changes present in the patients during the acute phase. The objective of the present study was to describe the clinical characteristics of patients with acute P. vivax infection and to evaluate a biochemical-hematological marker associated to signs of potential disease severity. This is a cross-sectional retrospective study, in which 130 patients with confirmed P. vivax infection were enrolled between June 2006 and January 2018. The clinical-epidemiological data were obtained from the medical records and the hematological and biochemical parameters were determined in automated equipment. The criteria established by WHO for severe falciparum malaria, with adaptation, such as creatinine> 1.5 mg/dL, axilar temperature> 40°C, dyspnea, mental alteration, parasitemia > 20,000/mm 3 , hemoglobin <7 mg/dL, hematocrit <20% were used for classification of potential malaria severity. The inflammatory marker analyzed was the aspartate aminotransferase to platelet ratio, known as APRI, which is classically used as an indicator of liver fibrosis in different liver diseases, and associated with inflammation in some infectious diseases. Of the 130 patients evaluated, 19 (14.6%) had one or more of the signs and symptoms indicative of malaria severity. The mean (SD) of APRI among patients with and without severity were, respectively, 2.11 and 1.09, the difference being statistically significant (p=0.044). Among patients with signs of severity, the proportion with APRI values above 1.5 U/L was 30%, higher than 10% of high APRI among those without signs of severity (p=0.007). The area under the ROC curve (IC95%) constructed to assess APRI accuracy was 0.645 (0.494; 0.795), resulting in a cut-off point = 0.74, with sensitivity of 74.0%, specificity of 56.0% and accuracy of 65.0%. These results suggest that APRI is elevated in patients with evidence of P.vivax complicated infection and may serve as a possible prognostic marker to assess the potential for severity during the acute phase of P. vivax infection.