Systematic Review: Enzyme Link Immunospot Assay For The Diagnosis Of Tuberculosis Infection

Objective To evealuate the quality of the current studies on the value of the diagnosis of enzyme link immunospot (ELISPOT) assay for rapid detection of tuberculosis. To estimate the accuracy of diagnosting tuberculosis using ELISPOT assay.Methods PubMed, EMBASE, CNKI were searched to retrieve relevant studies on detecting tuberculosis using ELISPOT assay. Articles selection and data extraction were carried out by two reviewers independently. Meta-disc software was used to handle data from included studies. The sensitivity (SEN), specificity (SPE),likelihood ratio(LR )and summary receiver operating characteristics (SROC) were used to assess the diagnostic value of ELISPOT assay. The included studies were analyzed by QUADAS.Results Eight studies were included according to the criteria, which included 492 patients with tuberculosis and 769 samples of non-tuberculosis as control.These eight studies had well controlled the bias of partial verification , differential verification , incorporation and withdrawals .The reference standard review could have a greater bias. The reporting quality were poorly reported. The heterogeneity (except for threshold effect) was found among these studies. The summarized accuracy indicators like sensitivity, specificity, and diagnostic odds ratio (DOR) were 94.0% [95% CI(92.0% -96.0%)], 62.0% [95% CI(58.0%-65.0%)],and 39.18 [95% CI(13.48-113.91)] respectively.The positive likelihood ratio(PLR)and negative likelihood ratio (NLR) were 3.30[95% CI(1.93-5.65)] and 0.10[95% CI(0.05-0.17)]. The area under of SROC curve was 0.9785 . The Q index was 0.9345.Conclusion The study demonstrated that the ELISPOT assay possibilities is a relatively sensitive method for rapid detection of tuberculosis. Due to the limitations such as bad design, low quality of experimental methods, different subjects, insufficient blind method, inconsistent reported standard, and not carrying on clinical decision analysis et al, the popularization of the new method is restricted. In view of these facts, as a new technology, the ELISPOT assay needs to be further tested by studies designed based on the STARD. In order to supply more general and reliable data, it is necessary to examine the economic effects of ELISPOT assay.