Elevated serum procalcitonin level in patients with chronic kidney disease without infection: A case-control study

Optimal cut-off value of procalcitonin and procalcitonin/albumin ratio for predicting bacteremia among patients living with cancer: a test-negative case-control study

OBJECTIVE

The occurrence of bacteremia is critically important for the survival of cancer patients. Therefore, our study aims to evaluate the efficacy of procalcitonin (PCT) and the procalcitonin to albumin ratio (PAR) in predicting bacteremia among this population.

METHODS

In this retrospective test-negative case-control study, we included 903 hospitalized cancer patients, divided into two groups: the bacteremia-positive group (BSI group, n = 384) and the bacteremia-negative group (non-BSI group, n = 519). We assessed the diagnostic significance of PCT and PAR through receiver operating characteristic (ROC) analysis and determined the optimal cut-off values using Youden's index.

RESULTS

Both the duration of hospital stay and the 30-day mortality rate were significantly higher in the BSI group. The areas under the curve (AUC) for PAR and PCT were 0.749 (95% CI: 0.715-0.782) and 0.742 (95% CI: 0.708-0.776), respectively, indicating higher levels in the BSI group. The optimal cut-off values for predicting bacteremia were 0.72 for PAR and 1.32 for PCT. PAR showed the highest specificity (92.7%) and positive predictive value (PPV = 83.4%), while PCT demonstrated the highest sensitivity (51.3%) and negative predictive value (NPV = 71.6%).

DISCUSSION

This study is the first in the literature to suggest that PAR and PCT are valuable biomarkers for diagnosing bacteremia in cancer patients. The identified cut-off values offer practical thresholds for bacteremia diagnosis.

A machine learning strategy to mitigate the inappropriateness of procalcitonin request in clinical practice

Aim

The aim of this study was to develop machine learning (ML) models to mitigate the inappropriate request of Procalcitonin (PCT) in clinical wards.

Material and methods

We built six different ML models based on both demographical data, i.e., sex and age, and laboratory parameters, i.e., cell blood count (CBC) parameters, inclusive of monocyte distribution width (MDW), and C-reactive protein (CRP). The dataset included 1667 PCT measurements of different patients. Based on a PCT cut-off of 0.50 ng/mL, we found 1090 negative (65.4%) and 577 positive (34.6%) results. We performed a 70:15:15 train:validation:test splitting based on the outcome.

Results

Random Forest, Support Vector Machine and eXtreme Gradient Boosting showed optimal performances for predicting PCT positivity, with an area under the curve ranging from 0.88 to 0.89.

Conclusions

The ML models developed could represent a useful tool to predict PCT positivity, avoiding unusefulness PCT requests. ML models are based on laboratory tests commonly ordered together with PCT but have the great advantage to be easy to measure and low-cost.

Impact of recombinant human brain natriuretic peptide on emergency dialysis and prognosis in end-stage renal disease patients with type 4 cardiorenal syndrome

Recombinant human brain natriuretic peptide (rhBNP) effects on type 4 cardiorenal syndrome (CRS) and adverse events such as heart failure rehospitalization and all-cause mortality have not been assessed in large-scale research. This study evaluated the impact of rhBNP on emergency dialysis and prognosis in end-stage renal disease (ESRD) patients with type 4 CRS, and the risk factors of emergency dialysis. This retrospective cohort study included patients with type 4 CRS and ESRD admitted for decompensated heart failure between January 2016 and December 2021. Patients were divided into the rhBNP and non-rhBNP cohorts, according to whether they were prescribed rhBNP. The primary outcomes were emergency dialysis at first admission and cardiovascular events within a month after discharge. A total of 77 patients were included in the rhBNP cohort (49 males and 28 females, median age 67) and 79 in the non-rhBNP cohort (47 males and 32 females, median age 68). After adjusting for age, residual renal function, and primary diseases, Cox regression analysis showed that rhBNP was associated with emergency dialysis (HR = 0.633, 95% CI 0.420-0.953) and cardiovascular events (HR = 0.410, 95% CI 0.159-0.958). In addition, multivariate logistic regression analysis showed that estimated glomerular filtration rate (eGFR) (OR = 0.782, 95% CI 0.667-0.917, P = 0.002) and procalcitonin (PCT) levels (OR = 1.788, 95% CI 1.193-2.680, P = 0.005) at the first visit were independent risk factors for emergency dialysis while using rhBNP was a protective factor for emergency dialysis (OR = 0.195, 95% CI 0.084-0.451, P < 0.001). This study suggests that RhBNP can improve cardiac function and reduce the occurrence of emergency dialysis and cardiovascular events in ESRD patients with type 4 CRS.

Unusual Extreme Leukocytosis in Metformin Overdose

We present the challenging differential diagnosis of an extreme leukocytosis noted at hospital admission of a patient with severe lactic acidosis and acute kidney injury secondary to metformin overdose. Laboratory and imaging work-up ruled out an infectious or malignant cause for severely increased leukocytes count; thus, it was established that the process of leukocyte demargination was the main cause of increased count of leukocytes. Discussion of available literature data is also presented. Our case report highlights the importance for clinicians to be aware of this possible spurious increase of leukocytes in acute non-infectious stressful conditions in order to avoid unnecessary antibiotics.

Antimicrobial Stewardship Techniques for Critically Ill Patients with Pneumonia

Pneumonia is common in the intensive care unit (ICU), infecting 27% of all critically ill patients. Given the high prevalence of this disease state in the ICU, optimizing antimicrobial therapy while minimizing toxicities is of utmost importance. Inappropriate antimicrobial use can increase the risk of antimicrobial resistance, Clostridiodes difficile infection, allergic reaction, and other complications from antimicrobial use (e.g., QTc prolongation, thrombocytopenia). This review article aims to discuss methods to optimize antimicrobial treatment in patients with pneumonia, including the following: procalcitonin use, utilization of methicillin-resistant Staphylococcus aureus nares testing to determine need for vancomycin therapy, utilization of the Biofire^® FilmArray^® pneumonia polymerase chain reaction (PCR), and microbiology reporting techniques.

Serum Interleukin-6 is associated with hypocalcemia, hypoferritinemia and hyperkalemia in end-stage renal disease patients

Background: Both of chronic inflammation and mineral disturbance are major concerns in patients with chronic kidney disease, particularly end-stage renal disease (ESRD). Objectives: The present study aimed to investigate the association between circulating IL-6 and minerals dysregulation in patients diagnosed with ESRF and on a continuous hemodialysis regimen. Methods: This cross-sectional study included 74 patients undergoing continuous hemodialysis. Serum samples were tested for IL-6 using an enzyme-linked immunosorbent assay. Mineral were analyzed using an electrolyte analyzer and biochemical tests. Parameter correlations were analyzed using the Pearson’s correlation test. Results: Among the studies group, the male: female ratio was 1:0.72. IL-6 mean value was 13.77 pg/ml ±9.79 SD. IL-6 was significantly negatively correlated with circulating iron and calcium levels (r= - 0.229, P= 0.049; r= -0.252, P= 0.03, respectively). IL-6 was significantly positively correlated with K+ levels (r= 0.269,P= 0.02). Conclusion: The present study highlighted the substantial role of IL-6 in mineral dysregulation in hemodialysis patients, highlighting this cytokine as a potential therapeutic target for minimizing and monitoring the clinical effects of mineral disturbances, including cardiovascular and neurological complications.

Ferritin and procalcitonin in COVID-19 associated acute kidney injury – gender disparities, but similar outcomes

Background: Acute kidney injury is a severe complication of COVID-19. Both COVID-19 and related acute kidney injury are reported in the literature to be more prevalent and more severe in males.

Methods: We performed a retrospective analysis of the COVID-19 associated acute kidney injury cases in order to search for differences between genders regarding patients’ and renal outcome.

Results: 250 patients with acute kidney injury were included in the study: 93 women (37.20%), 157 men (62.80%). There were no differences between sexes regarding age. Diabetes mellitus was significantly more present in women. Peak ferritin and procalcitonin levels were significantly higher in men, but other severity markers for COVID-19 did not differ between genders. There were no differences between sexes regarding history of chronic kidney disease, timing of acute kidney injury, need for dialysis or recovery of renal function. ICU admission and in-hospital mortality were similar between men and women.

Conclusions: In our study, COVID-19 related-AKI was more prevalent in men than in women, but the patients’ and renal outcome were similar. Significantly higher ferritin and procalcitonin serum levels registered in male patients when compared to women may have additional explanations beside more severe SARS-CoV-2 infection in males.

Predictive role of selected biomarkers in differentiating gram-positive from gram-negative sepsis in surgical patients: a retrospective study

INTRODUCTION

Patients after major surgery are at high risk of developing sepsis, which is accompanied by elevated serum levels of C-reactive protein (CRP) and procalcitonin (PCT). This study aimed to examine the differences in serum biomarker levels concerning the causative agent of sepsis in surgical patients.

MATERIAL AND METHODS

A retrospective study was carried out in the surgical intensive care unit (ICU) and included 81 septic patients admitted from January 2019 to May 2022, who had positive blood cultures (BC). Serum levels of PCT, CRP, white blood cells (WBC) and platelet counts were recorded on the day of the positive BC and over the following 3 days.

RESULTS

Patients with gram(-) sepsis had significantly higher PCT levels, and lower platelet count compared to patients with gram(+) sepsis. High PCT and low platelets levels in all measurements were a significant predictor of gram(-) isolate with the highest predictive value on the third day after BC sampling, with AUROC 0.821 (95% CI: 0.692-0.950), P = 0.001, and AUROC 0.676 (95% CI: 0.541-0.811), P = 0.02, respectively. In multivariate logistic regression, platelets the day after BC sampling and PCT on the third day made a significant contribution in distinguishing gam(+) from gram(-) BC. Age and high serum CRP levels were significant predictors of poor outcomes.

CONCLUSIONS

PCT and platelets may be useful biomarkers for predicting the causative agent of sepsis in surgical patients.

The Sustained and Marked Elevation of Serum Procalcitonin in a Hemodialysis Patient with Tuberculous Lymphadenitis, but Without the Evidence of Sepsis: A Case Report

Background

The elevation of serum procalcitonin (PCT) has been considered as a marker of systemic bacterial infection and sepsis. However, the marked elevation of PCT in non-sepsis conditions was rare. Here, we report a rare case of sustained markedly elevation of serum PCT in a dialysis patient with tuberculosis, but without the evidence of sepsis.

Case Presentation

A 25-year-old man on maintenance hemodialysis was admitted to the hospital for kidney transplantation. On admission, physical examination revealed multiple lymph nodes were palpable on both sides of the neck which was later confirmed as tuberculosis with biopsy pathology. On the 3rd day after admission, the patient suffered from fever with a temperature of 38.8°C. The white blood cells 12.35 × 10⁹/L and the PCT level was 5.73 ng/mL. Lately the PCT increased to 63.10 ng/mL, and the level of C-reactive protein was 186.00 mg/L. After the antibiotics upgraded from cefmetazole to meropenem, and vancomycin was added, the body temperature dropped to the normal range on the 17th day and remained normal thereafter. The PCT level declined gradually to 4.18 ng/mL on the 21st day and an antituberculosis regimen was started. After that, the PCT levels fluctuated between 2.9 ng/mL and 94.9 ng/mL without any manifestation of sepsis. The markedly elevation of serum PCT level persisted despite normal C-reactive protein level and leukocyte counts.

Conclusion

Persistently elevated serum PCT level might occur in conditions without evidence of sepsis. Taking consideration of multiple inflammatory factors to determine infection when the markedly elevated PCT level was not correlated with the clinical manifestations.

A retrospective cohort study of the effect of rapid versus delayed-result procalcitonin testing on antibiotic use at a community hospital

BACKGROUND

Procalcitonin is a serum biomarker used to distinguish bacterial infection from viral or noninfectious syndromes. Primary literature shows mixed data on use of procalcitonin for de-escalation of antimicrobials. Delays in test results of send-out procalcitonin assays may result in prolonged antimicrobial durations. It is unknown whether availability of rapid-result assays may shorten time to antibiotic de-escalation.

AIM

This retrospective, cohort study compared antibiotic durations of treatment between groups with rapid-result versus delayed send-out, procalcitonin test modality. This study was exempt from Ethics Committee Approval, as determined by the Institutional Review Board at the study site.

METHOD

Adult hospitalized patients were included if they had at least one procalcitonin test performed during the study period. The primary outcome compared mean duration of antimicrobial therapy between groups receiving a rapid-result procalcitonin test and a send-out test. Secondary outcomes included incidence of Clostridiodes difficile infection, mention of procalcitonin testing in the electronic medical record in reference to antimicrobial therapy decision making, and presence of comorbidities which affect procalcitonin levels independent of infection.

RESULTS

A total of 350 lab results were analyzed. The duration of antimicrobial treatment between groups was not statistically different with the median duration of treatment in the send-out group being 2.95 days compared to 3.35 in the rapid result group, p = 0.856. Patient comorbidities with potential to lead to a noninfectious elevation or falsely high level of procalcitonin were common.

CONCLUSION

Use of a rapid-result procalcitonin assay does not reduce hospital antimicrobial therapy duration as compared with send-out testing.

Clinico-bacterial and prognostic factors in patients with suspected blood stream infection and elevated serum procalcitonin levels

This study determined prognostic factors by comparing clinico-bacterial factors based on significant elevated serum procalcitonin levels in patients with suspected bloodstream infection (BSI). We retrospectively analyzed the medical records of 1,052 patients (age ≥16 years) with fever (temperature ≥38°C) and serum procalcitonin levels of ≥2.0 ng/mL, and blood culture results. The optimal cutoff value of the significant elevation of procalcitonin was determined using the minimum P-value approach. Clinico-bacterial factors were analyzed per the procalcitonin levels, and significant independent factors for short-term survival were investigated in 445 patients with BSI. Patients with suspected BSI were aged, on average, 72.3 ± 15.1 years, and the incidence of positive blood culture was 42.3%; and the 14-day survival was 83.4%. Procalcitonin ≥100 ng/mL was the most significant predictor for survival. Multivariate analysis in patients with suspected BSI showed that estimated glomerular filtration rate (eGFR) <30 mL/min/1.73 m² and procalcitonin ≥100 ng/mL were significant independent unfavorable prognostic factors. Microorganisms were similar between patients with procalcitonin level 2-99 ng/mL (n=359) and those with ≥100 ng/mL (n=86). Multivariate analysis in patients with BSI showed that eGFR <30 mL/min/1.73 m², procalcitonin ≥100 ng/mL, and primary infectious foci were significant independent prognostic factors. Patients with foci in the gastrointestinal tract and respiratory system had unfavorable 14-day survival. In conclusions, eGFR <30 mL/min/1.73 m² and procalcitonin ≥100 ng/mL were significant independent unfavorable prognostic factors for suspected BSI. Primary infectious foci (gastrointestinal tract and respiratory system) were associated with unfavorable short-term survival in patients with positive blood culture.

Procalcitonin serum levels in stage 5 chronic kidney disease children on hemodialysis

BACKGROUND

Infections are responsible for morbidity and mortality in children on hemodialysis (HD). Procalcitonin (PCT) is rarely used in this population, even though it is an efficient biomarker of infection and sepsis. Our aim was to study PCT baseline level in uninfected children with stage 5 chronic kidney disease (CKD 5) on HD, and determine how to use it in this population.

METHODS

Prospective observational study including 40 uninfected children on classical HD or hemodiafiltration (HDF) in three pediatric HD centers in the Paris region. PCT was monitored before and after three consecutive sessions within 1 week.

RESULTS

Median pre-dialysis PCT was 0.60 ng/mL [0.36-1.15], median post-dialysis PCT was 0.23 ng/mL [0.10-0.47], PCT reduction rate was 59.8% [37.5-75.8]. Seventy percent of pre-dialysis PCT were <1 ng/mL. Anuric patients had higher pre-dialysis PCT than those with residual urine output (0.70 [0.42-1.30] vs. 0.48 [0.30-0.93] ng/mL, p=0.01). HDF was more efficient than HD to clear PCT during sessions (reduction rate 75% [67-80] vs. 37 [31-50]), p<0.001).

CONCLUSION

PCT levels in pediatric HD patients without infection are higher than normal, but this increase is relatively moderate compared to massive increases of PCT in children with bacterial infections on HD. If PCT is measured after dialysis sessions, the specific technique-dependent reduction rates should be taken into consideration. Moderately increased PCT levels around 2 ng/ml should be interpreted with caution; however, higher PCT serum levels can be used to motivate rapid start of antibiotic treatment in pediatric HD patients.

Association of kidney function with effectiveness of procalcitonin-guided antibiotic treatment: a patient-level meta-analysis from randomized controlled trials

Objectives

Patients with impaired kidney function have a significantly slower decrease of procalcitonin (PCT) levels during infection. Our aim was to study PCT-guided antibiotic stewardship and clinical outcomes in patients with impairments of kidney function as assessed by creatinine levels measured upon hospital admission.

Methods

We pooled and analyzed individual data from 15 randomized controlled trials who were randomly assigned to receive antibiotic therapy based on a PCT-algorithms or based on standard of care. We stratified patients on the initial glomerular filtration rate (GFR, ml/min/1.73 m2) in three groups (GFR >90 [chronic kidney disease; CKD 1], GFR 15-89 [CKD 2-4] and GFR<15 [CKD 5]). The main efficacy and safety endpoints were duration of antibiotic treatment and 30-day mortality.

Results

Mean duration of antibiotic treatment was significantly shorter in PCT-guided (n=2,492) compared to control patients (n=2,510) (9.5-7.6 days; adjusted difference in days -2.01 [95% CI, -2.45 to -1.58]). CKD 5 patients had overall longer treatment durations, but a 2.5-day reduction in treatment duration was still found in patients receiving in PCT-guided care (11.3 vs. 8.6 days [95% CI -3.59 to -1.40]). There were 397 deaths in 2,492 PCT-group patients (15.9%) compared to 460 deaths in 2,510 control patients (18.3%) (adjusted odds ratio, 0.88 [95% CI 0.78 to 0.98)]. Effects of PCT-guidance on antibiotic treatment duration and mortality were similar in subgroups stratified by infection type and clinical setting (p interaction >0.05).

Conclusions

This individual patient data meta-analysis confirms that the use of PCT in patients with impaired kidney function, as assessed by admission creatinine levels, is associated with shorter antibiotic courses and lower mortality rates.

Clinical characteristics and prognostic risk factors of anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAV)

OBJECTIVE

The complement alternative pathway is involved in the development of AVV. Several studies showed that AVV patients with low serum complement C3 (sC3) levels tend to have a poor prognosis. The aim of this study was to determine whether low sC3 measured at AAV onset is a risk factor for survival prognosis in patients with AVV, and further identified other potential risk factors for predicting patient survival prognosis.

METHODS

A retrospective analysis of 52 newly onset AAV patients was performed. The clinical parameters of the AAV patients were collected. The laboratory parameters before immunosuppressive treatment were evaluated. According to the level of sC3, the patients were divided into low sC3 group (n = 19) and normal sC3 group (n = 33). Disease outcome measures included end-stage renal disease (ESRD) or death. The clinical parameters and survival rate between the two groups were compared. Spearson correlation analysis was used to analyze the correlation between sC3 and other laboratory parameters.

RESULTS

Significant differences were found regarding Birmingham Vasculitis Activity Score (BVAS), sC3, sC4, lactate dehydrogenase, blood urea nitrogen, procalcitonin (PCT), and estimated glomerular filtration rate (eGFR) between the two groups (p = 0.006, 0.000, 0.001, 0.049, 0.019, 0.000 and 0.045, respectively). The survival rate of the low sC3 group was significantly lower than that of the normal sC3 group (Log Rank Chi-square = 4.416, P = 0.036). Low sC3 was significantly associated with lower sC4 (r = 0.570, P = 0.000), lower serum albumin (r = 0.311, P = 0.025), lower eGFR (r = 0.289, P = 0.037), higher PCT (r = -0.566, P = 0.000), and higher lactate dehydrogenase (r = -0.323, P = 0.019).

CONCLUSION

This retrospective study demonstrates that AAV patients with low sC3 level at diagnosis tend to have lower baseline eGFR and poorer survival prognosis than those of the normal sC3 level. Furthermore, the high procalcitonin (PCT), low serum albumin and high lactate dehydrogenase in AVV patients may be predictors of poor prognosis.

Independent Predictive Ability of Procalcitonin of Acute Kidney Injury among Critically Ill Patients

It is unclear whether serum procalcitonin (PCT) levels rise in patients with acute kidney injury (AKI), and it is also unclear whether the elevation of PCT levels in this setting is independent of the existence of infection and impaired renal clearance. We conducted a retrospective study in a regional teaching hospital in Taiwan to evaluate the AKI-predictive ability of serum PCT among critically ill patients. We enrolled 330 patients (mean age, 70.5 ± 16.4 years; 57.0% men) who were admitted to the intensive care unit (ICU) from 1 July 2016, to 31 December 2016, and who had serum PCT measurement performed within 24 h after ICU admission. We used the generalized additive model and generalized linear model to evaluate the association of serum PCT levels and renal function variables. In addition, we used the multivariate logistic regression method to demonstrate serum PCT level as an independent predictor of AKI in both the non-infected patients (odds ratio (OR) = 1.38, 95% confidence interval (CI) = 1.12–1.71, p = 0.003) and the infected patients (OR = 1.23, 95% CI = 1.03–1.46, p = 0.020). In conclusion, serum PCT level at ICU admission is an independent predictor of developing AKI irrespective of infection among critically ill patients.

Elevated serum procalcitonin level in patients with chronic kidney disease without infection: A case-control study

Background

Inflammation is a necessary component of chronic kidney disease (CKD) that can be attributed to an accumulation of toxins and a reduced clearance of proinflammatory cytokines. Procalcitonin (PCT) is a widely applied biomarker in the diagnosis of infection, and considering the presence of pre‐existing inflammation in CKD patients, the PCT level could be high in such a population; however, no reference value for PCT in CKD patients has been available to date.

Methods

During the present study period, 361 CKD patients and 119 healthy controls were included. The PCT level and other biochemistry parameters were assayed by using a COBAS system. Statistical analysis was conducted to compare the differences in PCT levels and other biochemistry parameters between the two groups, and linear regression was used to assess the correlation between two variables. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the performance of PCT and the optimal cutoff value to differentiate between CKD patients and healthy controls.

Results

The PCT level in CKD patients was significantly higher than that in healthy controls, and among the CKD patients, the PCT level was increased with advanced clinical stage. Moreover, PCT was moderately correlated with CysC. The optimal off‐value was 0.075 with a sensitivity of 94.7% and specificity of 90.8%.

Conclusion

The PCT level was significantly higher in CKD patients than in healthy controls, and the reference value for CKD patients should be adjusted to avoid unnecessary antibiotic treatments which may pose a negative impact on residual renal function.