The Coutinho index as a simple tool for screening patients with advanced forms of Schistosomiasis mansoni: a validation study. (16th March 2021)

• Record Type: Journal Article
• Authors: Barreto, Ana V M S; Domingues, Ana L C; Diniz, George T N; Cavalcanti, Ana M S; Lopes, Edmundo P; Montenegro, Silvia M L; Morais, Clarice N L
• Is Part Of: Transactions of the Royal Society of Tropical Medicine and Hygiene. Volume 116:Number 1(2022)
• Page Start: 19
• Page End: 25
• Publication Date: 2021-03-16
• Subjects: alkaline phosphatase -- biological index -- biomarkers -- liver fibrosis -- platelets -- Schistosomiasis mansoni; Tropical medicine -- Periodicals; 616.9883
• DOI: 10.1093/trstmh/trab040
• Languages: English
• ISSNs: 0035-9203

Abstract

Abstract: Background: Periportal fibrosis (PPF) is the major pathological consequence of Schistosoma mansoni infection. The Coutinho index—the alkaline phosphatase (ALP) to platelet ratio ([ALP/upper limit of normality {ULN}]/platelet count [10 6 /L] x 100)—was validated. Validation consisted of modest laboratory tests to predict advanced PPF. Methods: A total of 378 individuals from an endemic area of Brazil with a previous history of the disease and/or a positive parasitological examination were evaluated. We used ultrasound examination as the gold standard for classification of the PPF pattern and measured the biological markers of the index. Results: Forty-one individuals (10.8%) without PPF, 291 (77%) with moderate PPF and 46 (12.2%) with advanced PPF, were identified. ALP and platelet count were used for the index. The cut-off point ≥0.228 predicted the presence of fibrosis with an area under the receiver operating characteristic curve (AUROC) of 0.56, sensitivity of 68.6% and specificity of 46.3%. There was an absence of PPF in 46.3% of individuals without fibrosis and the presence of PPF in 68.5% of cases with moderate and advanced ultrasound fibrosis. The identification of advanced fibrosis with a cut-off point ≥0.316 revealed an AUROC curve of 0.70, sensitivity of 67.4% and specificity of 68.3%, thus confirming the advanced phase in 65.2% of cases compared with ultrasound. Conclusion: The Coutinho index was able to predict advanced PPF in most individuals. It is valid as a new tool, uses routine laboratory tests and therefore is more accessible for screening patients with a severe form of the disease in endemic areas.