Diagnostic Performance of Bronchoalveolar Lavage Fluid CD4/CD8 Ratio for Sarcoidosis: A Meta-analysis

• CD4/CD8 ratio in bronchoalveolar lavage fluid can be a useful supplement to other diagnostic methods for sarcoidosis.
• Results suggest that the ratio can be a useful supplement to other diagnostic methods.Sarcoidosis is a granulomatous inflammatory disease that can be challenging to diagnose. Based on meta-analysis of an extensive evidence base, our study concludes that measuring the CD4/CD8 ratio in bronchoalveolar lavage fluid can be useful for diagnosing sarcoidosis, when used in parallel with other diagnostic tools. We recommend measuring this ratio in patients strongly suspected of having sarcoidosis who cannot tolerate more invasive biopsy.

BackgroundThe usefulness of bronchoalveolar lavage fluid (BALF) CD4/CD8 ratio for diagnosing sarcoidosis has been reported in many studies with variable results. Therefore, we performed a meta-analysis to estimate the overall diagnostic accuracy of BALF CD4/CD8 ratio based on the bulk of published evidence.MethodsStudies published prior to June 2015 and indexed in PubMed, OVID, Web of Science, Scopus and other databases were evaluated for inclusion. Data on sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), and diagnostic odds ratio (DOR) were pooled from included studies. Summary receiver operating characteristic (SROC) curves were used to summarize overall test performance. Deeks's funnel plot was used to detect publication bias.ResultsSixteen publications with 1885 subjects met our inclusion criteria and were included in this meta-analysis. Summary estimates of the diagnostic performance of the BALF CD4/CD8 ratio were as follows: sensitivity, 0.70 (95%CI 0.64–0.75); specificity, 0.83 (95%CI 0.78–0.86); PLR, 4.04 (95%CI 3.13–5.20); NLR, 0.36 (95%CI 0.30–0.44); and DOR, 11.17 (95%CI 7.31–17.07). The area under the SROC curve was 0.84 (95%CI 0.81–0.87). There was no evidence of publication bias.ConclusionMeasuring the BALF CD4/CD8 ratio may assist in the diagnosis of sarcoidosis when interpreted in parallel with other diagnostic factors.