Development and validation of a whole-cell ELISA for serologically diagnosing Helicobacter pylori infection in Brazilian children and adults: a diagnostic accuracy study

Autor(es)

Ogata, Silvio Kazuo ^[1] ; Camorlinga-Ponce, Margarita ^{[2, 3]} ; Hernandes Granato, Celso Francisco ^[4] ; da Silveira Rohr, Maria Rachel ^{[5, 6]} ; Neto, Ricardo Artigiani ^[6] ; Kawakami, Elisabete ^[1]

Afiliação do(s) autor(es)

^[1] Univ Fed Sao Paulo EPM UNIFESP, Escola Paulista Med, Discipline Pediat Gastroenterol, Dept Pediat, Sao Paulo, SP - Brazil

^[2] Univ Fed Sao Paulo EPM UNIFESP, Escola Paulista Med, Sao Paulo, SP - Brazil

^[3] UMAE Hosp Pediat, Inst Mexicano Seguro Social, Infect Dis Res Unit, Mexico City, DF - Mexico

^[4] Univ Fed Sao Paulo EPM UNIFESP, Escola Paulista Med, Dept Med, Discipline Parasit & Infect Dis, Sao Paulo, SP - Brazil

^[5] Univ Fed Sao Paulo EPM UNIFESP, Escola Paulista Med, Dept Med, Discipline Gastroenterol, Sao Paulo, SP - Brazil

^[6] Univ Fed Sao Paulo EPM UNIFESP, Escola Paulista Med, Dept Med, Discipline Clin Pathol, Sao Paulo, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: São Paulo Medical Journal; v. 136, n. 5, p. 442-448, SEP-OCT 2018.
• Citações Web of Science: 0

Resumo

ABSTRACT BACKGROUND: Serological tests are practical, with low cost, but no noninvasive tests are available for diagnosing Helicobacter pylori (H. pylori) infection in Brazil. The aim here was to develop and validate enzyme-linked immunosorbent assay (ELISA) serological tests to detect anti-H. pylori immunoglobulin G antibodies, based on cultured strains from Brazilian patients. DESIGN AND SETTING: Cross-sectional, diagnostic accuracy study comparing a locally developed and validated ELISA and invasive tests among dyspeptic patients at two public hospitals in São Paulo, Brazil. METHODS: An ELISA test was prepared using whole-cell antigen from 56 strains. After genotypic characterization, it was standardized and optical density (OD) cutoffs were determined based on the serum antibody response of 100 H. pylori-negative samples, compared with 82 H. pylori-positive samples. Validation was performed on 174 symptomatic patients. RESULTS: The optimal OD cutoffs established (for monoclonal and polyclonal tests, respectively) were 0.167 and 0.164; overall ELISA sensitivity: 84.3%, 78.9%; specificity: 88.6%, 90.6%; positive predictive value (PPV): 75.4%, 80%; negative predictive value (NPV): 93.1%, 81.8%; accuracy: 87.3%, 86.2%; child and adolescent ELISA sensitivity: 74.2%, 81.8%; specificity: 90.8%, 86.7%; PPV: 66.6%, 84.3%; NPV: 95.8%, 84.8%; accuracy: 88.5%, 84.6; adult ELISA sensitivity: 84.4%, 75%; specificity: 86.9%, 93%; PPV: 81.8%, 78.3%; NPV: 88.9%, 91.8%; accuracy: 85.9%, 88.5%. CONCLUSION: The polyclonal serological test developed using local strains presented better diagnostic performance among children and adolescents, while the monoclonal test was better among adults. The results from both tests suggest that these in-house serological tests could be used to detect anti-H. pylori antibodies in our population, for screening purposes. (AU)

• Processo FAPESP: 14/25298-5 - Validação de teste de sorologia por ensaio imunoenzimático ELISA para diagnóstico da infecção por Helicobacter pylori no soro
• Beneficiário: Elisabete Kawakami
• Modalidade de apoio: Auxílio à Pesquisa - Regular