Median (ranges) protein and LDH results in pleural fluid and serum and their ratios from the three different analytical platforms on 44 paired samples
| Laboratory A | Laboratory B | Laboratory C | p Value | |
|---|---|---|---|---|
| Pleural fluid LDH (U/L) | 160 (34–1398) | 118 (21–781) | 159 (28–741) | a=<0.001 b=<0.001 c=NS |
| Serum LDH (U/L) | 285 (135–865) | 240 (59–734) | 364 (146–1291) | a=<0.001 b=<0.001 c=<0.001 |
| Pleural fluid to serum LDH ratio | 0.54 (0.13–5.50) | 0.44 (0.09–3.90) | 0.45 (0.10–2.20) | a=<0.001 b=NS c=<0.001 |
| Pleural fluid total protein (g/L) | 28 (9–47) | 31 (10–57) | 30 (11–49) | a=<0.001 b=NS c=<0.001 |
| Serum total protein (g/L) | 56 (39–65) | 58 (43–70) | 56 (38–67) | a=NS b=NS c=NS |
| Pleural fluid to serum total protein ratio | 0.49 (0.20–0.80) | 0.52 (0.23–0.83) | 0.53 (0.22–0.83) | a=<0.001 b=NS c=<0.001 |
Where a is laboratory B compared with laboratory A, b is laboratory B compared with laboratory C and c is laboratory C compared with laboratory A. NS is p>0.05.
LDH, lactate dehydrogenase; NS, not significant.