The use of rapid diagnostic test of Procalcitonin serum levels for the postmortem diagnosis of sepsis

Because serum Procalcitonin is reported to be a valid postmortem marker of sepsis, this prospective study was carried out to determine whether the semi-quantitative PCT-Q®-Test (B.R.A.H.M.S., Germany) is a reliable indicator of postmortem Procalcitonin (PCT) serum levels, thus enabling a quick “tableside” diagnosis of sepsis. Postmortem PCT-levels of 70 forensic and 78 clinical-pathological autopsy cases (n = 148) were examined using the B·R·A·H·M·S-PCT-Q®-Test during autopsy. 27 cases were categorized as the cases of sepsis according to the ACCP/SCCM Consensus Conference criteria. 121 cases were assigned to the non-sepsis group. Among the 148 cases, 18 samples could not be analyzed by the reason of strong hemolysis.Using a cut-off point of 2 ng/ml, 20 cases of sepsis were identified (true positive) whereas 3 cases of sepsis were not detected (false negative). In the non-sepsis group (107 cases) 6 cases showed a positive testing (false positive). When applied within 48 h postmortem, the PCT-Q®-Test showed a sensitivity of 86.96% and a specificity of 94.39% (at cut-off 2 ng/ml). Likelihood ratios and positive predictive values proved to be lower in the forensic autopsy group (PPV: 59.3% in forensic case vs. 85.1% in clinicopathological cases; NPV: 98.73% in forensic cases vs. 95.2% in clinicopathological cases). The PPVs using a cut-off point of 10 ng/ml were 100% in both groups independent of sepsis prevalences.The results show, that a high NPV for prevalences ranging from 3% to 30% can be reached using a 2 ng/ml cut-off point, whereas a cut-off of 10 ng/ml ensures a high PPV for the respective prevalences in the absence of exclusion criteria. The study provides strong evidence that the introduction of rapid diagnostic test (RDTs) of postmortem PCT serum levels may be useful in achieving rapid distinction between sepsis and non-sepsis-related causes of death, especially in conjunction with the medical case history and further autopsy results. In addition, the use of RDTs enables clinicians to conduct an evidence-based validation of clinical diagnosis, thus facilitating future clinical decision-making.