Serum procalcitonin as a biomarker of bloodstream infection & focal bacterial infection in febrile patients

Scrub typhus-leptospirosis co-infection in India: a systematic review and meta-analysis

Scrub typhus and leptospirosis are re-emerging zoonotic infections with significant morbidity and mortality rates in India. Overlapping aetiological and epidemiological patterns indicate a high possibility of their co-infection in India, which can be a diagnostic challenge due to non-specific clinical features. A systematic search of the PubMed/MEDLINE, Scopus and Embase databases was conducted to identify relevant studies published through 31 August 2023. Studies reporting co-infection of scrub typhus and leptospirosis among the Indian population were included. Data extraction, quality assessment and statistical analysis were performed in accordance with established guidelines. Six studies met the inclusion criteria, comprising a total of 58 co-infection cases. Pooled prevalence of scrub typhus-leptospirosis co-infection among acute undifferentiated febrile illness patients was 3.7% (95% confidence interval [CI] 0.00 to 0.126). Among scrub typhus patients, the prevalence of co-infection with leptospirosis was 13.7% (95% CI 0.027 to 0.304). Significant heterogeneity was observed among the included studies, highlighting the need for cautious interpretation of prevalence estimates. This meta-analysis underscores the clinical importance of scrub typhus-leptospirosis co-infection in India and emphasizes the need for enhanced clinical awareness, improved diagnostic strategies and targeted research efforts to address this emerging infectious disease threat.

The Roles of Vitamin D Levels, Gla-Rich Protein (GRP) and Matrix Gla Protein (MGP), and Inflammatory Markers in Predicting Mortality in Intensive Care Patients: A New Biomarker Link?

OBJECTIVES

Identifying reliable biomarkers to predict mortality in critically ill patients is crucial for optimizing management in intensive care units (ICUs). Inflammatory and metabolic markers are increasingly recognized for their prognostic value. This study aims to evaluate the association of various inflammatory and metabolic markers with ICU mortality.

METHODS

This prospective observational study was conducted from January 2023 to January 2024 in the City Hospital's ICU. A total of 160 critically ill patients were enrolled. Laboratory parameters, including white blood cell (WBC) count, red cell distribution width (RDW), platelet count, neutrophil count, mean platelet volume (MPV), monocyte count, lymphocyte count, procalcitonin (PCT), C-reactive protein (CRP), calcium (Ca++), and vitamin D levels, were analyzed. Additionally, ratios such as the platelet-to-lymphocyte ratio (PLR), neutrophil-to-lymphocyte ratio (NLR), systemic inflammatory index (SII), and pan-immune-inflammation value (PIV) were calculated. Plasma levels of Gla-rich protein (GRP) and dephosphorylated uncarboxylated matrix Gla protein (dp-ucMGP) were measured using ELISA.

RESULTS

The mean age of the patients included in the study was 60.5 ± 15.8 years. Cardiovascular disease was present in 72 patients (45%), respiratory system disease in 58 (36%), and chronic kidney disease (CKD) in 38 (24%). Additionally, 61 patients (38%) had diabetes, and 68 (42%) had hypertension. Inflammatory markers, including PLR, NLR, and PIV, were all significantly higher in non-survivors, while calcium and vitamin D levels were lower (p < 0.05). Higher WBC, RDW, neutrophil count, PLR, NLR, PIV, CRP, procalcitonin, GRP, and dp-ucMGP levels were positively correlated with longer hospital stays and increased mortality. In contrast, platelet and lymphocyte counts were negatively correlated with both outcomes (p < 0.05). Vitamin D levels showed an inverse relationship with both hospital stay and mortality, indicating that lower levels were associated with worse outcomes (p < 0.05). In multiple logistic regression analysis, elevated WBC count (OR = 1.20, p = 0.02), RDW (OR = 1.35, p = 0.01), neutrophil count (OR = 1.25, p = 0.01), MPV (OR = 1.20, p = 0.02), PLR (OR = 1.30, p = 0.01), NLR (OR = 1.40, p = 0.001), PIV (OR = 1.50, p = 0.001), CRP (OR = 1.32, p = 0.01), procalcitonin (OR = 1.45, p = 0.001), GRP (OR = 1.40, p = 0.001), and dp-ucMGP (OR = 1.30, p = 0.001) levels were significantly associated with increased mortality.

CONCLUSIONS

Inflammatory and metabolic markers, particularly NLR, PLR, PIV, GRP, and dp-ucMGP, are strong predictors of mortality in ICU patients. These markers provide valuable insights for risk stratification and early identification of high-risk patients, potentially guiding more targeted interventions to improve outcomes.

A comparative study on the use of procalcitonin to distinguish between central fever and infectious causes of fever

Introduction

central fever is defined as elevated body temperature without any evidence of infection or drug reaction fever, and currently it has no definitive diagnostic criteria. The current study aims to assess the role of procalcitonin (PCT) in differentiating central fever from fever secondary to infections in patients with neurological insults.

Methods

we conducted a retrospective study of patients admitted with a neurological insult (brain trauma, brain tumors and cerebrovascular accidents) in a tertiary care hospital. All patients who developed fever 48 hours after admission and had procalcitonin, C-reactive protein (CRP), and Erythrocyte sedimentation rate (ESR) done as part of fever evaluation were assessed to include in the study.

Results

out of 70 patients who met inclusion criteria, 37 had infections identified and 33 had no source of infection. The mean age was 42.9 years (± 18) in the infectious group while 40.3 years (± 18.2) in the central fever group and there was male predominance in both groups. In the infectious group there were 25(67.6%) males vs. 12(32.4%) females while in non -infectious group, males vs. females were 18(54.5%) vs. 15(45.5%) and there was no difference in both group (p-value 0.26) Median procalcitonin (PCT) value was 0.09 ng/dl (IQR 0.05- 0.19) in patients with no identified cause of infection and 1.4 ng/dl (IQR 0.5-5.1) in patients with infections with a p-value of <0.001. Although CRP and ESR were low in patients with central fever as compared to those with infections, these differences did not reach statistical significance with p-value of CRP 0.18 and p-value of ESR 0.31 between two groups.

Conclusion

PCT levels were low in patients with central fever and may be considered as a useful biomarker to differentiate between infectious fever from non-infectious fever in patients with brain injury. This can prevent unnecessary antibiotic use in patients without infection.

The predictive utility of cytokines, procalcitonin and C-reactive protein among febrile pediatric hematology and oncology patients with severe sepsis or septic shock

Severe sepsis and septic shock are life-threatening for pediatric hematology and oncology patient receiving chemotherapy. Th1/Th2 cytokines, C-reactive protein (CRP), and procalcitonin (PCT) are all thought to be associated with disease severity. The aim of this study was to prospectively verify the utility of Th1/Th2 cytokines and compare them with PCT and CRP in the prediction of adverse outcomes. Data on patients were collected from January 1, 2011, to December 31, 2020. Blood samples were taken for Th1/Th2 cytokine, CRP, and PCT measurements at the initial onset of infection. Severe infection (SI) was defined as severe sepsis or septic shock. Th1/Th2 cytokine levels were determined by using flow cytometric bead array technology. In total, 7,735 febrile episodes were included in this study. For SI prediction, the AUCs of IL-6, IL-10 and TNF-α were 0.814, 0.805 and 0.624, respectively, while IL-6 and IL-10 had high sensitivity and specificity. IL-6 > 220.85 pg/ml and IL-10 > 29.95 pg/ml had high odds ratio (OR) values of approximately 3.5 in the logistic regression. Within the subgroup analysis, for bloodstream infection (BSI) prediction, the AUCs of IL-10 and TNF-α were 0.757 and 0.694, respectively. For multiorgan dysfunction syndrome (MODS) prediction, the AUC of CRP was 0.606. The AUC of PCT for mortality prediction was 0.620. In conclusion, IL-6 and IL-10 provide good predictive value for the diagnosis of SI. For children with SI, IL-10 and TNF-α are associated with BSI, while CRP and PCT are associated with MODS and death, respectively.

Evaluation of Plasmatic Procalcitonin in Healthy, and in Systemic Inflammatory Response Syndrome (SIRS) Negative or Positive Colic Horses

Simple Summary

Procalcitonin (PCT) increased in the case of systemic inflammatory response syndrome (SIRS), especially due to bacterial infection. The correlation between SIRS score and plasma PCT levels in horses have not been evaluated, and no studies investigated plasma PCT concentration over time. In the present study, PCT and SIRS score were evaluated in colic horses at admission to the hospital and at 24, 48, 72 and 96 h. Statistically differences were detected between healthy vs. all colic horses and between healthy vs. SIRS positive or SIRS negative horses. No correlation was observed between SIRS score and PCT. This suggests a role of plasmatic PCT as good biomarker for colic.

Abstract

Colic horses show systemic inflammatory response syndrome (SIRS) clinical signs. Procalcitonin (PCT) showed increased circulating levels in sick horses. This study compares plasma PCT concentrations in healthy vs. SIRS negative/positive colic horses over time, and evaluates PCT and SIRS score potential correlation, to verify the usefulness of PCT for the evaluation of SIRS severity. Ninety-one horses were included; 43/91 were healthy, on basis of physical examination, blood work and SIRS score (score = 0), while 48/91 were sick colic horses, classified as SIRS-negative (score < 2) and positive (score ≥ 2). Moreover, a 0–6 point-scale SIRS score was calculated (assessing mucous membrane color and blood lactate concentration). PCT was evaluated at admission, and at 24, 48, 72 and 96 h, using a commercial kit for equine species. We verified by the ANOVA test PCT differences between healthy vs. colic horses, healthy vs. SIRS-negative or SIRS-positive colic horses, at all sampling times, and the correlation between the SIRS score at admission with the SIRS score. Statistically significant differences were detected between healthy vs. all colic horses and between healthy vs. SIRS-positive or negative horses at all sampling times. No correlation was observed between the SIRS score at admission and PCT values. PCT was statistically higher in colic horses compared to the healthy ones, suggesting a role as a biomarker for colic.