Table 2. Univariate analysis of potential variables influencing the test performance of perforin during AR.
| Variables | Subgroups | Number of independent data sets | Sensitivity (95% CI) | Specificity (95% CI) | DOR (95% CI) | AUC | |
| Publication year | before 2000 | 5 | 0.81 (0.69–0.90) | 0.90 (0.81–0.95) | 43.52 (14.19–133.46) | 0.9406 | |
| after 2000 | 12 | 0.84 (0.78–0.90) | 0.85 (0.79–0.89) | 24.90 (12.82–48.37) | 0.9028 | ||
| Sample origin | graft biopsy | 6 | 0.80 (0.68–0.89) | 0.88 (0.79–0.94) | 35.11 (12.02–102.56) | 0.9210 | |
| PBL | 7 | 0.80 (0.69–0.89) | 0.86 (0.78–0.92) | 21.32 (7.97–57.09) | 0.9028 | ||
| urine | 4 | 0.89 (0.80–0.95) | 0.85 (0.75–0.92) | 36.76 (13.59–99.39) | 0.9158 | ||
| PCR techniques | RT-PCR | 8 | 0.85 (0.76–0.91) | 0.84 (0.78–0.89) | 25.23 (9.59–66.37) | 0.9056 | |
| competitive RT-PCR | 6 | 0.80 (0.68–0.89) | 0.90 (0.81–0.95) | 37.94 (13.51–106.56) | 0.9370 | ||
| real-time quantitative RT-PCR | 3 | 0.86 (0.71–0.95) | 0.87 (0.73–0.96) | 33.35 (9.26–120.09) | 0.9196 | ||
| Housekeeping gene | cyclophilin | 4 | 0.89 (0.80–0.95) | 0.85 (0.75–0.92) | 36.76 (13.59–99.39) | 0.9158 | |
| β-actin | 5 | 0.80 (0.66–0.90) | 0.89 (0.81–0.95) | 34.38 (10.16–116.35) | 0.9372 | ||
| 18s rRNA | 2 | 0.69 (0.39–0.91) | 0.83 (0.65–0.94) | 12.03 (0.96–151.24) | unavailable a | ||
| GAPDH | 6 | 0.83 (0.72–0.91) | 0.85 (0.76–0.92) | 33.45 (12.12–92.34) | 0.9194 | ||
| All | 17 | 0.83 (0.78–0.88) | 0.86 (0.82–0.90) | 28.79 (16.26–50.97) | 0.9107 | ||
a
Three independent data points are required at least to draw an SROC curve.
Abbreviations: DOR, diagnostic odds ratio; CI, confidence interval; AUC, area under the curve of the SROC curve; PBL, peripheral blood leukocyte; PCR, polymerase chain reaction; RT-PCR, reverse transcription polymerase chain reaction; GAPDH, glyceraldehyde-3-phosphate dehydrogenase.