Dados do Trabalho

Título

Laboratory Performance in Molecular Detection of Mycobacterium tuberculosis Through Analysis of External Quality Assessment Program Results: WHO-Recommended Tests Outperform Others

Introdução

Tuberculosis (TUB) is a leading cause of death with prompt detection critical. External Quality Assessment Programs (EQAP) ensure the accuracy, reliability, and harmonization of laboratory (LAB) results.

Objetivo (s)

To evaluate the overall performance of participating LABs in 3 EQAP related to TUB organized by a Brazilian provider: M. tuberculosis molecular detection (MTB), Rifampicin resistance detection (RIF), and Isoniazid resistance detection (INH).

Material e Métodos

The EQAP samples were suspensions of human cells, with or without the addition of cultured, inactivated, and lyophilized M. tuberculosis. Labs received 2 samples quarterly for testing accuracy (ACC), sensitivity (SEN), and specificity (SPE). The Mann-Kendall test (MKT) assessed ACC trends over time. Furthermore, kit-type ACCs for in-vitro diagnostic (IVD) vs. laboratory-developed tests (LDT), World Health Organization recommended (WHOR) vs. other kits (non-WHO), and methods (qPCR vs. PCR) were compared.

Resultados e Conclusão

In the MTB EQAP, 63 labs participated over 20 rounds, achieving 96.6% ACC, 97.5% SEN, and 94.9% SPE. The MKT found no significant ACC trends over time (τ = -0.91, p =0.36). IVDs outperformed LDTs with 97.8% vs. 87.9% ACC (OR=6.0, 95%CI 3.42-20.9, p<0.0001). WHOR kits were more accurate than non-WHO kits, 98.2% vs. 90.4% (OR=5.96, 95%CI 1.05-12.7, p<0.0001). qPCR exceeded the ACC of PCR, 97.2% versus 74% (OR=12.1, 95%CI 4.8-32.9, p<0.0001). For RIF EQAP, 49 labs in 9 rounds, showed 97.4% ACC, 97.2% SEN, and 97.6% SPE. In the INH EQAP, 7 LABs over 7 rounds, reached 95.2% ACC, 100% SEN, and 94.1% SPE. Differences between types of kits and methods for RIF and INH, as well as trends over time, were not significant or could not be calculated due to the limited number of samples.
The MTB EQAP underscored the high participation and suitability of labs, along with excellent diagnostic performance; IVD kits were 6 times more likely to yield adequate results than LDTs. WHOR kits were 5.9 times more likely to produce adequate results than non-WHO kits. qPCR was 12.6 times more likely to achieve adequate results than PCR. Despite fewer participants in RIF and INH, their performance rates were high; more data are needed for conclusive results on kit and method types. This study affirms the quality of molecular diagnostics for TUB in Brazil, informs on kit and method selection, and underscores the critical role of EQAPs in combating a significant global health issue.

Palavras Chave

Tuberculose