Figure 4.

Fibrin(ogen) is abundant and proteins of immune cells are present in the proteome of plastic bronchitis airway casts. (A) Fibrin(ogen) is an abundant protein in the airway cast proteome. Mucin proteins were detected but at much lower levels relative to the most abundant proteins in the casts (also see Figure E4). Consistent with the results of the immunophenotyping studies, immune cell proteins were detected in the cast proteome. (B) Neutrophil proteins were the most abundant followed by (C) eosinophil, (D) monocyte/macrophage, and (E) lymphocyte proteins. Eosinophil proteins were not detected in one of the three cast samples and detected lymphocyte proteins were those associated with B cells; no T-cell proteins were detected. Data are the normalized spectral abundance factors of each respective protein in each of three plastic bronchitis airway casts.