RÉSUMÉ
Introduction: The laboratory diagnosis of syphilis is given by a positive treponemal test and a non-treponemal test, with VDRL (Veneral Disease Research Laboratory) being the "gold standard". Objective: To compare two tests commercially validated for biological fluids and analyzed by different operators, in order to assess their performance in detecting high (≥:8) and low (≤1:2) titrations, as well as to determine the agreement between results in paired serum samples from patients with syphilis and living with HIV. Methods: Cross-sectional study, approved by the Research Ethics Committee of the teaching hospital Gaffrée e Guinle (HUGG), under CAAE 66558117.0.0000.5258. The study population was composed by patients diagnosed with syphilis and confirmed by the positivity of one or more treponemal tests. All samples were analyzed simultaneously by two different operators, each using a kit: VDRL WAMA Diagnóstica®, São Carlos, SP, Brazil; VDRL Brás, Laborclin®, Pinhais, PR, Brazil. The SPSS statistical program was used. Results: 110 serum samples from patients diagnosed with syphilis treated at HUGG were analyzed. The frequency of high VDRL titrations among patients, following the VDRL criterion ≥1:8, was practically the same in both tests, with 68% in VDRL Laborclin and 69% in VDRL WAMA (p = 0.87) and VDRL ≤1:2, 80% for WAMA and 83% for Laborclin (p = 0.72). The results of VDRL were tabulated in pairs; then the Cohen's Kappa coefficient of agreement was calculated (Κ) 0.32 (95%CI 0.210.41; p<0.00001), as well as the weighted Kappa (Kw) and the intraclass correlation coefficient (ICC) 0.89 (95%CI 0.840.92; p<0.00001). The Bland-Altman diagram was also used. We found poor agreement between the VDRL tests when results were nominally concordant, that is, with the same titles in both tests. However, if partial agreement is considered, the interpretation of the magnitude of agreement estimators was almost complete (≥0.80). Conclusion: Reliability and agreement were high between the VDRL tests of both manufacturers when considering the close titrations (up to two dilutions). Further reliability and agreement studies are essential between the non-treponemal tests available and used in Brazil.
Introdução: O diagnóstico laboratorial da sífilis é realizado por meio da positividade de um teste treponêmico e de um teste não treponêmico, sendo o VDRL (do inglês Veneral Disease Research Laboratory) o "padrão ouro". Objetivo: Comparar dois testes comercialmente validados para fluidos biológicos e analisados por operadores diferentes, com o intuito de avaliar o desempenho dos testes em detectar titulações altas (≥ :8) e baixas (≤1:2), bem como determinar a concordância entre ambos os resultados em amostras pareadas de soro de pacientes com sífilis vivendo com HIV. Métodos: Estudo transversal, aprovado pelo Comitê de Ética em Pesquisa do Hospital Universitário Gaffrée e Guinle (HUGG), sob o CAAE: 66558117.0.0000.5258. A população estudada foi a de pacientes que obtiveram o diagnóstico de sífilis confirmado por meio da positividade de um ou mais testes treponêmicos. Todas as amostras foram analisadas simultaneamente por dois operadores diferentes, cada um utilizando um kit: VDRL WAMA Diagnóstica®, São Carlos, SP, Brasil; VDRL Brás, Laborclin®, Pinhais, PR, Brasil. Utilizou-se o programa estatístico SPSS. Resultados: Foram analisadas 110 amostras de soro de pacientes com diagnóstico de sífilis atendidos no HUGG. A frequência de altas titulações de VDRL entre os pacientes, seguindo o critério de VDRL ≥1:8, foi praticamente a mesma em ambos os testes, com 68% no VDRL Laborclin e 69% no VDRL WAMA (p=0,87) e para VDRL ≤1:2, 80% para WAMA e 83% para Laborclin (p=0,72). Os resultados dos títulos de VDRL foram tabulados em pares; em seguida, foram calculados o coeficiente de concordância Kappa de Cohen (Κ) 0,32 (IC95% 0,210,41; p<0,00001), o Kappa ponderado (Kw) e o coeficiente de correlação intraclasse (CCI) 0,89 (IC95% 0,840,92; p<0,00001), bem como utilizado o diagrama de Bland-Altman. O estudo encontrou fraca concordância entre os testes de VDRL, se considerados os resultados nominalmente concordantes, isto é, com os mesmos títulos em ambos os testes. Entretanto, se considerado a concordância parcial, a interpretação da magnitude dos estimadores de concordância passou a ser quase completa (≥0,80). Conclusão: A confiabilidade e a concordância foram altas entre os testes de VDRL dos dois fabricantes, quando consideradas as titulações próximas (até duas diluições). Mais estudos de confiabilidade e concordância são fundamentais entre os testes não treponêmicos disponíveis e utilizados no Brasil.
Sujet(s)
Humains , Syphilis , VIH (Virus de l'Immunodéficience Humaine) , Tests sérologiques , Études transversales , Morbidité , Hôpitaux universitairesRÉSUMÉ
Background: Tuberculosis (TB) is an infectious lung disease with high worldwide incidence that severely compromises the quality of life in affected individuals. Clinical tests are currently employed to monitor pulmonary status and treatment progression. The present study aimed to apply a three-dimensional (3D) reconstruction method based on chest radiography to quantify lung-involvement volume of TB acute-phase patients before and after treatment. In addition, these results were compared with indices from conventional clinical exams to show the coincidence level. Methods: A 3D lung reconstruction method using patient chest radiography was applied to quantify lung-involvement volume using retrospective examinations of 50 patients who were diagnosed with pulmonary TB and treated with two different drugs schemes. Twenty-five patients were treated with Scheme I (rifampicin, isoniazid, and pyrazinamide), whereas twenty-five patients were treated with Scheme II (rifampicin, isoniazid, pyrazinamide, and ethambutol). Acute-phase reaction: Serum exams included C-reactive protein levels, erythrocyte sedimentation rate, and albumin levels. Pulmonary function was tested posttreatment. Results: We found strong agreement between lung involvement and serum indices pre- and posttreatment. Comparison of the functional severity degree with lung involvement based on 3D image quantification for both treatment schemes found a high correlation. Conclusions: The present 3D reconstruction method produced a satisfactory agreement with the acute-phase reaction, most notably a higher significance level with the C-reactive protein. We also found a quite reasonable coincidence between the 3D reconstruction method and the degree of functional lung impairment posttreatment. The performance of the quantification method was satisfactory when comparing the two treatment schemes. Thus, the 3D reconstruction quantification method may be useful tools for monitoring TB treatment. The association with serum indices are not only inexpensive and sensitive but also may be incorporated into the assessment of patients during TB treatment.(AU)