BAL fluid protein profiles. BAL fluid protein levels were measured from samples collected at the time of IPS diagnosis (IPS-Dx) and compared with levels found in BAL fluid obtained from healthy persons not receiving transplants (Cont (NL)), and HCT recipients with chronic noninfectious lung dysfunction (Cont (HCT)) as described in “Patient controls.” BAL fluid levels of total protein and several inflammatory mediators were elevated at the time of IPS. Data are expressed as mean plus or minus SEM. Significant differences between specific groups are shown; n = 5 to 14 per group.