TNF and susceptibility to pneumonia measurement: IVIG treatment had no effect on the inflammatory response to S. pneumoniae pneumonia, both in terms of inflammatory cell numbers (S2 Fig) or levels of the pro-inflammatory cytokine TNF-α in BALF post-infection (control group 2828 SEM 670 versus IVIG group 2665 SEM 506 pg/ml) in the lavage fluid following infection).