Monocyte-to-lymphocyte, neutrophil-to-lymphocyte and neutrophil-to-monocyte plus lymphocyte ratios in children with active tuberculosis: A multicentre study

Aim: Higher number of monocytes and neutrophils may correlate with active tuberculosis (TB) in children. However, the few paediatric studies available are limited by the small numbers of children with TB disease or infection included.Methods: We calculated the monocyte-to-lymphocyte-ratio (MLR), neutrophil-to-lymphocyte-ratio (NLR) and neutrophil-to-monocyte-plus-lymphocyte-ratio (NMLR) in children with active TB, latent TB infection (LTBI), other infectious and non-infectious conditions and healthy children evaluated in two referral centres in Rome.Results: Overall, 649 children were included (41.8% females, mean age of 5.74 years). MLR, NLR and NMLR values were always significantly higher in patients with TB compared with the other groups (p < 0.001). Considering the entire population with the outcome of TB diagnosis, NMLR, with a cut-off of 1.2, had a sensitivity of 63% and a specificity of 76% (AUC: 0.71 [0.64-0.78]); NLR, with a cut-off of 1.5, had a sensitivity of 61% and a specificity of 79% (AUC: 0.72 [0.65-0.79]); MLR, considering a cut-off of 0.2, was less sensitive (56%) but more specific (82%) with a similar AUC (0.72 [0.65-0.79]).Conclusion: Our study provides further evidence that MLR, NLR and NMLR can serve as first level diagnostics to support the clinical suspicion of TB in children.