MCP-1 levels in children with ILD. MCP-1 levels in bronchoalveolar lavage fluid (BALF) of children with interstitial lung diseases (ILD) and healthy controls are shown at the (A) protein and at the (B) mRNA level. (C) MCP-1 levels in BALF of ILD children with and without pulmonary fibrosis. Pulmonary fibrosis was assessed by computed tomography according to [36,37]. (D) MCP-1 levels in ILD children related to ILD disease severity according to the criteria of Fan . 1 = asymptomatic, no desaturation; 2 = symptomatic but normoxic (> 90%) under all conditions; 3 = symptomatic with desaturation during sleep or exercise; 4 = symptomatic with desaturation at rest; MCP-1 protein levels were quantified in BALF by a multiplex, particle-based assay (Bio-Rad Laboratories, Minneapolis, USA) as described previously . MCP-1 mRNA levels were quantified in BALF cells by Real time RT-PCR using SYBR green and the iCycler iQ detection system (Biorad, Hercules, CA, USA) and were normalized to GAPDH. Median values are shown by horizontal bars. Differences between the patient groups were tested with the Mann-Whitney U test; * p < 0.05, *** p < 0.001; Children with systemic corticosteroid therapy are shown as grey circles. P: Pulmonary alveolar proteinosis; S: Sarcoidosis; † symbolize children who died due to respiratory failure.