Fig. 3

Disturbed NK cell function in IgAVN patients. (a) Decreased cytotoxicity of NK cells in IgAVN compared to sl-IgAV patients. NK cells from HC, IgAVN and sl-IgAV were incubated with calcein-AM-labelled K562 cells. LU 30/10⁶ cells were calculated using the inverse of the number of effectors needed to lyse 30% of the tumour cells × 100. (b) The number of CD107a⁺ NK cells significantly increased after stimulation with PHA and IL-2 in HC and in sl-IgAV patients while only a minor increase was observed in IgAVN patients. (c) After 5 h of incubation with PMA and ionomycin there was a limited decrease in intracellular perforin in IgAVN patients, while decrease was significant in HC. IFN-γ (d) and MIP-1β (e) were significantly decreased in IgAVN patients’ cell culture supernatants after stimulation with IL-2 compared to HC. Data are expressed as medians (Q25-Q75) of each group. NK cells, natural killer cells; IgAV, immunoglobulin A vasculitis; HC, healthy controls; IgAVN, IgAV with renal involvement; sl-IgAV, skin-limited IgAV; LU, lytic units; PHA, phytohaemagglutinin; IL-2, interleukin-2; PMA, phorbol 12-myristate 13-acetate; IFN-γ, interferon-γ; MIP-1β, macrophage inflammatory protein-1β