The neutrophil-to-lymphocyte ratio and mean platelet volume can be associated with severity of valvular involvement in patients with acute rheumatic carditis.

OBJECTIVE: The aim of the study was to investigate the association between the severity of acute rheumatic carditis (ARC) and the neutrophil-lymphocyte ratio (NLR) and mean platelet volume (MPV).

METHODS: Paediatric patients diagnosed with ARC between 2010 and 2016 and age- and gender-matched controls were retrospectively analysed. At the time of diagnosis, we reviewed the demographic features obtained: echocardiographic data, complete blood count reports, acute-phase reactants, including C-reactive protein, and erythrocyte sedimentation rate values. The patient group was further divided into two subgroups according to the degree of valvular regurgitation, which included those with severe and those with mild-to-moderate valvular regurgitation.

RESULTS: The number of cases with ARC and age- and gender-matched controls were 120 and 50, respectively. The mean age of the patients was 12.25 ± 2.89 (range: 7-18) years. NLR, MPV, anti-streptolysin-O, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), haemoglobin level, and white blood cell (WBC) and neutrophil count were significantly higher in patients with acute carditis compared with the controls ( p < 0.001). NLR was found to have a significantly positive correlation with CRP ( r = 0.177, p = 0.001), ESR (r = 0.81, p = 0.03) and WBC count ( r = 0.47, p = 0.001). Moreover, we found a positive correlation between NLR and severity of valvular regurgitation (r = 0.34, p < 0.001), and a negative correlation between MPV and severity of valvular regurgitation ( r = -0.38, p < 0.05) in our patients. In multiple linear regression analysis, severe valvular regurgitation was associated with NLR (0.51; 95% CI: 0.32-0.68; p = 0.006) and MPV ( -0.78; 95% CI: -0.72 to -0.98; p = 0.008).

CONCLUSIONS: NLR and MPV are novel inflammatory markers and simple, rapid and easily accessible prognostic parameters that can be associated with severity of valvular involvement in patients with ARC.