DIAGNOSTIC AND PROGNOSTIC VALUE OF INTERLEUKIN-6 AND C-REACTIVE PROTEIN IN COMMUNITY-ACQUIRED PNEUMONIA

The diagnostic and prognostic value of admission serum levels of inter leukin-6 (IL-6) and C-reactive protein (CRP) was investigated in 203 h ospital-treated patients with community-acquired pneumonia (CAP). In s erum samples obtained during the first 24 h after admission, IL-6 was detectable in 198 patients (98%), with a median value of 50 ng/l. Ten % of the patients had IL-6 values of 1000 ng/l. A clear positive corre lation between IL-6 and CRP was found (r = 0.29, p < 0.0001). Patients with high IL-6 or CRP levels had longer duration of fever, longer hos pital stay, and had less often recovered clinically or radiographicall y on follow-up weeks after discharge, A high IL-6, but not a high CRP, also seemed to be associated with a higher mortality. Bacteremic pneu mococcal pneumonia had the highest levels of IL-6 (mean 2852 and media n 420 ng/l) and CRP (mean 292 and median 285 mg/l). High IL-6 values w ere also seen in patients with non-bacteremic pneumococcal pneumonia, while all patients with pneumonia due to other bacterial, or viral, ae tiology had IL-6 levels of less than or equal to 300 ng/l, In conclusi on, IL-6 and CRP are promising diagnostic and prognostic tools in the management of CAP. Further studies are needed to establish the usefuln ess of repeated measurements early in the hospital course of the disea se.