Sputum Cytokine Concentrations. Concentrations of (A) IL-6, (B) sIL-6R and (C) CCL3 in induced sputum from HNS, S and COPD patients. Each dot represents the data from an individual patient. The horizontal bar represents the median value. The dotted line represents the lower limit of quantification (LLOQ) for the respective analytes. (B) 1 COPD subject had sIL-6R levels registering below the LLOQ. (C) 6 HNS and 12 S had CCL3 levels registering below the lower limit of quantification.