TABLE 1

Immune cells in idiopathic pulmonary fibrosis (IPF) and systemic sclerosis-associated interstitial lung disease (SSc-ILD)

SSc-ILDIPF
Macrophage activationIL-4 and IL-13 induce shift to M2IL-4 and IL-13 induce shift to M2
Macrophage phenotypeScavenger receptor CD163, the IL-1RII decoy receptor, mannose receptorsScavenger receptor CD163, the IL-1RII decoy receptor, mannose receptors
Macrophage  chemokinesIL-10, CCL18, PARC, IL-13, IL-1 receptor antagonist, IL-8, CCL17, CCL2, CCL18, CXCL8, CCL22, S100A9, PDGF and TGF-βIL-10, CCL18, PARC, IL-13, IL-1 receptor antagonist, IL-8, CCL17, CCL2, CCL18, CXCL8, CCL22, S100A9, PDGF and TGF-β
T-lymphocyte  subpopulationsTh2-increased Tregs, Th22, Th17, decreased CXCR3/CXCR4 ratio, increased CD4/CD8 ratio, αvβ3, αvβ5, α4β7Th2-decreased Tregs, decreased CXCR3/CXCR4 ratio, increased CD4/CD8 ratio,
T-lymphocyte  chemokinesIL-4, IL-5, IL-6, IL-10, IL-13 and IL-22IL-4, IL-5, IL-10 and IL-13
B-lymphocyteCD19 overexpression, CD19 polymorphism, lymphoid aggregates, elevated BLyS, autoantibody productionElevated BLyS, autoantibody production
NK lymphocyte  infiltrationYesYes
Mast cell infiltrationNoYes
Polymorphonuclear cell  infiltrationYesYes
Polymorphonuclear cell  activityElastases, oxidative damageElastases, oxidative damage

  • IL: interleukin; IL-1RII: IL-1 receptor, type II; PARC: pulmonary activation-regulated chemokine; PDGF: platelet-derived growth factor; TGF: transforming growth factor; Th: T-helper cell; Tregs: regulatory T-cells; BLyS: B-lymphocyte stimulator; NK: natural killer.