Fig. 1.

Intracellular cytokine profile of circulating neutrophils in peripheral blood from non-infected (NI) (▪ = 16), asymptomatic (AS) (▴ = 20), oligosymptomatic (OL) (• = 13) and HAM/TSP (HT) ♦ = 11) individuals, after short-term in vitro incubation, particularly in the absence of exogenous stimuli. The frequency of cytokine-expressing neutrophils was determined within gated SSC^high CD16^high+ cells. The results are expressed as scattering of individual values and mean percentage of interleukin (IL)-12⁺ (a), interferon (IFN)-γ⁺ (b), tumour necrosis factor (TNF)-α⁺ (c), IL-4⁺ (d) and IL-10⁺ (e) neutrophils. Letters ‘a’ and ‘b’ represent statistically significant differences (P < 0·05) compared to non-infected (NI) and asymptomatic (AS) groups, respectively.