Myristic acid is identified as a metabolite with the highest diagnostic sensitivity and specificity in the metabolome of patients with bacteraemia. Its significant decrease has been observed in patients with septic shock not responding to treatment. Another study has reported a close correlation of myristic acid levels with the outcome of severe trauma patients. Myristic acid concentrations were investigated in a cohort of septic patients and patients with Systemic Inflammatory Response Syndrome (SIRS) in 5 consecutive days following diagnosis and compared to healthy controls. The study population groups-Sepsis 34, SIRS 31, and Healthy Control 120 patients were included. Serum samples were analyzed using gas chromatography and mass spectrometry. The myristic acid levels in the Sepsis Group and SIRS Group were found to be significantly higher when compared to healthy controls. The serum concentration of myristic acid in septic patients with bacteraemia was higher than in septic patients without bacteraemia. Most patients with sepsis and SIRS had the highest levels of myristic acid within 24 h after an established diagnosis. Myristic acid should be considered as a new candidate marker of severe inflammation and sepsis. A simplified analysis and sufficient body of validated data are necessary steps towards the introduction of this metabolite into routine clinical practice.

• Keywords
• SIRS, bacteraemia, biomarker, gas chromatography/mass spectrometry (GC/MS), myristic acid, sepsis, septic shock,
• Publication type
• Journal Article MeSH

INTRODUCTION: Procalcitonin (PCT) and C-reactive protein (CRP) are established markers of infection in the general population. In contrast, several studies reported falsely increased PCT levels in patients receiving T-cell antibodies. We evaluated the validity of these markers in patients scheduled for hemopoietic stem cell transplantation receiving anti-thymocyte globulin (ATG) during conditioning. We also assessed renal and liver functions and their relationship to PCT and CRP changes. METHODS: Twenty-six patients without clinical signs of infection were prospectively studied. ATG was administered in up to three doses over the course of 5 days. PCT, CRP, white blood cell (WBC) count, urea, creatinine, glomerular filtration rate, bilirubin, alanin amino-transferase (ALT), and gamma-glutamyl transferase (GGT) were assessed daily during ATG administration. Pharyngeal, nose, and rectal swabs and urine samples were cultured twice weekly. Blood cultures were obtained if clinical symptoms of infection were present. RESULTS: Baseline (BL) levels of both PCT and CRP before ATG administration were normal. WBC count decreased after ATG administration (P = 0.005). One day after ATG administration, both PCT and CRP levels increased significantly, returning to BL levels on day 4. Microbiological results were clinically unremarkable. There was no interrelationship between PCT levels and BL markers of renal or liver functions (P > 0.05 for all comparisons). Bilirubin and GGT were increased on days 2 to 5 and ALT was increased on day 3 (P < 0.05 versus BL). No difference in renal functions was observed. Three patients developed bacterial infection on days 7 to 11 with different dynamics of PCT and CRP. There was no association between the number of ATG doses and PCT levels or between the risk of developing infection and previous PCT levels. CONCLUSIONS: ATG triggered a marked early surge in PCT and CRP followed by a steady decrease over the course of 3 days. The dynamics of both PCT and CRP were similar and were not associated with infection. PCT levels were independent of renal and liver functions and were not predictive of further infectious complications. A direct effect of ATG on T lymphocytes could be the underlying mechanism. Hepatotoxic effect could be a contributing factor. Neither PCT nor CRP is a useful marker that can identify infection in patients receiving ATG.

• MeSH
• Antilymphocyte Serum administration & dosage   therapeutic use   MeSH
• Biomarkers blood   MeSH
• C-Reactive Protein analysis   MeSH
• Adult MeSH
• Immunosuppressive Agents administration & dosage   therapeutic use   MeSH
• Liver Function Tests MeSH
• Calcitonin blood   MeSH
• Middle Aged MeSH
• Humans MeSH
• Young Adult MeSH
• Calcitonin Gene-Related Peptide MeSH
• Predictive Value of Tests MeSH
• Preoperative Care * MeSH
• Prospective Studies MeSH
• Protein Precursors blood   MeSH
• Sensitivity and Specificity MeSH
• Sepsis diagnosis   MeSH
• Hematopoietic Stem Cell Transplantation * MeSH
• Kidney Function Tests MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Young Adult MeSH
• Male MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Validation Study MeSH
• Names of Substances
• Antilymphocyte Serum MeSH
• Biomarkers MeSH
• C-Reactive Protein MeSH
• CALCA protein, human MeSH Browser
• Immunosuppressive Agents MeSH
• Calcitonin MeSH
• Calcitonin Gene-Related Peptide MeSH
• Protein Precursors MeSH