CD4 and HIV infectious disease: Moreover, calprotectin levels were negatively correlated with the absolute CD4+ T-cells count (Fig. 6g, r = − 0.402; p < 0.05), as well as with HIV infection and ART duration (Fig. 6h, r = − 0.371, p < 0.05 and Fig. 6i, r = − 0.363, p < 0.05, respectively); which emphasises the impact of gut inflammation in the immune reconstitution of HIV+ patients despite ART.