Relationship of CXCL10, CCL3, VCAM and TNFR2 concentration between groups. CXCL10, CCL3, VCAM and TNFR2 concentration (Fig. 1a–d respectively) were significantly higher in discordant versus non-discordant samples. No significant differences were observed between samples with high (CSF >1log10 plasma) versus low (CSF 0.5–1log10 plasma or ultrasensitive discordance) degrees of discordance. Samples with ultrasensitive discordance are represented with an open circle. Mediator concentrations correlated with CSF HIV-1 RNA (Fig. 1e–h). Non-disc, non-discordant; Low-disc, low-discordant; High-disc, high-discordant; ns, not significant; CXCL10, inducible protein 10; VCAM, vascular cell adhesion molecule; CCL3, monocyte inflammatory protein 1a; TNFR2, tumour necrosis factor receptor 2.