Quantitative C-reactive protein in pulmonary infections.

A total of 207 cases were selected to evaluate the diagnostic value of C-reactive protein (CRP) in pulmonary infections. The mean +/- SD of CRP values in various pulmonary infections were as follows: 18.62 +/- 11.34 micrograms/ml for 32 cases of exudative-fibrotic tuberculosis; 15.98 +/- 16.66 micrograms/ml for 15 cases of tuberculous pneumonia; 25.61 +/- 18.96 micrograms/ml for 29 cases of tuberculous effusion; 16.66 +/- 10.18 micrograms/ml for 11 cases of tuberculous cavity; 81.1 +/- 24.9 micrograms/ml for 10 cases of miliary tuberculosis; 36.4 +/- 22.1 micrograms/ml for 19 cases of mycoplasmal pneumonia; 241 +/- 72 micrograms/ml for 38 cases of bacterial pneumonia; 225 +/- 65 micrograms/ml for 30 cases of bacterial pneumonia with effusion; 169 +/- 50 micrograms/ml for 16 cases of lung abscess. The CRP values of other pulmonary infections were as follows: 20.6, 20.8 micrograms/ml for two cases of Strongyloides stercoralis pneumonia; 7.4, 1.6 micrograms/ml for two cases of aspergilloma; 11.2, 12.4, 7.6 micrograms/ml for three cases of Pneumocystis carinii pneumonia. Serial changes in CRP values in 13 cases of well-treated bacterial pneumonia showed that values of CRP decreased to below half of the initial value on the 3rd to 4th day, and returned to about normal value on the 10th to 13th day. The study suggested that: a) various types of infections had different levels of CRP values, b) level of CRP values was determined both by the pathogen and the severity of inflammation, c) serial CRP values in bacterial infection could be used as a guide in treatment.