Table 1.

Summary of commonly studied asthma endpoints affected by different types of ENMs

ENM	Asthma Models	AHR	BALF Cell Profile	Serum IgE	Cytokines	Direct Effects	References
TiO2	OVA, TDI	↑	↑↑neutrophils	↑↑	↑IL-1, ↑IL-6, ↑IL-4	↑AHR, ↑mucus, ↑T cell proliferation	[16–21, 61–64]
Silica	OVA	↑↑	↑↑eosinophils	↑↑↑	↑↑IL-4, ↓IFN-γ, ↑IL-5, ↑IL-13, ↑IL-1	–	[22–27]
Ag	OVA	↓	↓total count	↑	↓↓IL-4, ↓IL-13, ↓IL-5	–	[28–31, 68]
Au	OVA, TDI	↓	↓total counts, ↑eosinophils	No change	–	–	[21, 34–37]
Fe	OVA	–	↓eosinophils	↓	↓IL-4, ↓IFN-γ	–	[38, 39]
Zn	OVA	–	↑eosinophils	No change	↑IL-4, ↑IL-13, ↑IL-5	↑eosinophils, ↑IL-4, ↑IL-13	[40]
Cu	OVA	↑	↑total count	↑	–	↑IL-6, ↑IL-8, ↑Muc5ac	[41, 65, 67]
Ni	T-bet–/–	–	↑eosinophils	–	↑CCL2	↑eosinophils, ↑eotaxin	[42, 66]
Ce	–	–	–	–	–	↑IL-4, ↑IL-5	[63]
C	OVA	↑	↑macrophages	–	↓IL-4, ↓IL-13	–	[43–47]
Polymer	OVA	–	↓total count, ↓eosinophils	↓	↓IL-4, ↓IL-13	–	[48–49]
CNT	OVA, HDM, TMA	↑↑	↑↑eosinophils, ↑neutrophils	↑↑↑	↑IL-4, ↑IL-13, ↑eotaxin, ↑IL-5	↑↑AHR, ↑IgE, ↑mucus, ↑IL-4, ↑IL-13	[50–57, 69–74]

Arrows indicate average relative enhancement/suppression.