Journal of Clinical Medicine Research, ISSN 1918-3003 print, 1918-3011 online, Open Access
Article copyright, the authors; Journal compilation copyright, J Clin Med Res and Elmer Press Inc
Journal website https://jocmr.elmerjournals.com

Original Article

Volume 18, Number 4, April 2026, pages 251-260

A Strong Correlation Between Pleural Fluid and Serum C-Reactive Protein Levels Across a Spectrum of Pleural Effusions

Figures

↓  Figure 1. Correlation between CRPpf and CRPs in the TrPE group. CRPs: serum C-reactive protein; CRPpf: pleural fluid C-reactive protein; r: correlation coefficient; TrPE: transudative pleural effusion.
Figure 1.
↓  Figure 2. Correlation between CRPpf and CRPs in the UCPPE group. UCPPE: uncomplicated parapneumonic effusion; CRPs: serum C-reactive protein; CRPpf: pleural fluid C-reactive protein; r: correlation coefficient.
Figure 2.
↓  Figure 3. Correlation between CRPpf and CRPs in the CPPE group. CPPE: complicated parapneumonic effusion; CRPs: serum C-reactive protein; CRPpf: pleural fluid C-reactive protein; r: correlation coefficient.
Figure 3.
↓  Figure 4. Correlation between CRPpf and CRPs in the MPE group. MPE: malignant pleural effusion; CRPs: serum C-reactive protein; CRPpf: pleural fluid C-reactive protein; r: correlation coefficient.
Figure 4.
↓  Figure 5. Correlation between CRPpf and CRPs in the TPE group. TPE: tuberculous pleural effusion; CRPs: serum C-reactive protein; CRPpf: pleural fluid C-reactive protein; r: correlation coefficient.
Figure 5.

Tables

↓  Table 1. Age and CRP Levels (CRPs and CRPpf) Across TrPE, UCPPE, CPPE, MPE, and TPE Groups
 
VariableTrPE (n = 210)UCPPE (n = 86)CPPE (n = 60)MPE (n = 126)TPE (n = 10)
aP < 0.0001 versus UCPPE and TPE; bP < 0.003 versus UCPPE and TPE; cP < 0.001 versus UCPPE and TPE. SD: standard deviation; CRP: C-reactive protein; CI: confidence interval; CRPs: serum CRP; CRPpf: pleural fluid CRP; TrPE: transudative pleural effusion; UCPPE: uncomplicated parapneumonic effusion; CPPE: complicated parapneumonic effusion; MPE: malignant pleural effusion; TPE: tuberculous pleural effusion.
Age (years), mean ± SD77.3 ± 10.4a65.9 ± 18.174.1 ± 13.6b75.9 ± 10.2c66.1 ± 19.2
CRPs (mg/L), mean ± SD11.3 ± 5.7145.3 ± 67.6302.2 ± 75.656.1 ± 39.598.7 ± 12.9
  95% CI10.5–12.1130.5–160.1283.9–320.423.3–71.091.4–107.9
CRPpf (mg/L), mean ± SD4.6 ± 2.858.5 ± 38.5112.0 ± 65.018.9 ± 13.945.0 ± 9.4
  95% CI4.2–5.019.2–85.196.0–128.07.6–28.18.3–51.7

 

↓  Table 2. Correlation Between Levels of CRPpf and CRPs for Various Groups of PE With Its Correlation Coefficient (r) and Its Statistical Significance (P)
 
VariableTrPE (n = 210)UCPPE (n = 86)CPPE (n = 60)MPE (n = 126)TPE (n = 10)
aP < 0.001 versus CPPE, bP = 0.009 versus TrPE, cP < 0.0001 versus CPPE, dP = 0.029 versus MPE, eP < 0.01 versus TrPE and MPE. CRPs: serum CRP; CRPpf: pleural fluid CRP; TrPE: transudative pleural effusion; UCPPE: uncomplicated parapneumonic effusion; CPPE: complicated parapneumonic effusion; MPE: malignant pleural effusion; TPE: tuberculous pleural effusion.
r0.81a0.9b, c, d0.570.82a0.91c, e
P< 0.0001< 0.0001< 0.0001< 0.0001< 0.0001