The following is a summary of “Examining pancreatic stone protein response in ICU-acquired bloodstream infections: a matched event analysis,” published in the May 2024 issue of Critical Care by Verlaan et al.

PSP (Pancreatic Stone Protein) shows promise as a general infection biomarker in patients with critical illness, but its role in specifically identifying ICU-acquired bloodstream infections (BSI) remains unclear.

Researchers conducted a retrospective study investigating the potential of PSP as a biomarker for risk stratification in patients with ICU-acquired BSI.

They analyzed ICU-acquired BSI caused by Gram-negative rods (GNR), enterococci, or Candida species. Episodes were matched based on ICU stay duration at infection onset, Severe Organ Failure Assessment (SOFA) score, immune deficiency presence, and renal replacement therapy use. The PSP concentrations were measured at infection onset (To) and 24, 48, and 72 hours before infection onset, defined by the first positive blood culture. Differences in PSP levels among pathogen groups were assessed using a one-way analysis of variance. Sensitivity to new or worsening systemic inflammation was analyzed using markers like C-reactive protein, white cell count, and fever.

The result showed an examination of 30 BSI cases from each pathogen group. The BSI began on day 9 (IQR 6–12). The PSP levels were generally high (381 (237–539) ng/ml), with 18% of data exceeding the assay’s measuring range. Over time, there was no apparent pattern across all 90 BSI cases (median change 34 (−75–189) ng/ml from T-72 to T0). The PSP concentrations for GNR, enterococci, and Candida species were 406 (229–497), 350 (223–608), and 480 (327–965) ng/ml at the beginning of infection, respectively (P=0.322). Absolute PSP levels and trends did not significantly differ between pathogens at any particular point. The PSP levels and SOFA scores were associated with T0. Of the 90 BSI incidents, 18 (20%) showed no signs of a systemic inflammatory response, mainly in the case of Candida species. Sensitivity analysis of 72 instances revealed no noticeable between-group differences or changes in PSP concentration before BSI started.

Investigator concluded that despite very high PSP levels in patients with ICU-acquired BSI, neither time trends nor differences between pathogens were evident before infection onset.

Source: icm-experimental.springeropen.com/articles/10.1186/s40635-024-00634-7