Procalcitonin and C-reactive protein levels in neonatal infections

Comparison of procalcitonin with interleukin 8, C-reactive protein and differential white blood cell count for the early diagnosis of bacterial infections in newborn infants

OBJECTIVE

To evaluate procalcitonin (PCT) as a test for early diagnosis of bacterial infections (BI) in newborn infants and to compare the results of PCT with those of interleukin 8 (IL-8), C-reactive protein (CRP) and differential white blood cell count.

STUDY DESIGN

PCT was prospectively measured along with IL-8, CRP and differential white blood cell counts and blood cultures in 197 newborn infants at the first suspicion of bacterial infection. PCT, IL-8, CRP and differential white blood cell counts were analyzed for sensitivity, specificity and positive and negative predictive values after receiver operating characteristic curve analysis for best thresholds. The kinetics of PCT was determined in infants with and without BI.

RESULTS

Forty-six infants were diagnosed clinically as having BI, of whom 9 had BI with positive blood cultures. At a cutoff value of 0.50 microg/l, PCT detected combined culture-proved and clinical BI with a sensitivity of 57% (95% confidence interval, 41%, 71%) and a specificity of 66% (95% confidence interval, 57%, 74%). The combination of IL-8 > or =70 ng/l and/or CRP >10 mg/l achieved a sensitivity of 91% (95% confidence interval, 79%, 98%) and a specificity of 73% (95% confidence interval, 64%, 81%). PCT values of infected and not infected infants tended to rise for 24 h after initial evaluation and then decreased.

CONCLUSION

The combination of IL-8 and CRP is more reliable than PCT as a test for early diagnosis of BI in newborn infants.

Rapid diagnostic methods in the detection of sepsis

Any delay in the management of infection is deleterious, especially in patients whose illness is severe. It is of paramount importance to shorten this delay. This article emphasizes the different ways to reach this goal, including the use of new biologic markers, such as cytokines or procalcitonin.

[The value of procalcitonin in neonatal infections]

The value of procalcitonin (PCT) measurement is not presently completely assessed for the diagnosis of neonatal infections.

PATIENTS AND METHODS

This parameter was assessed in a prospective study in the neonatal intensive care unit of Clermont-Ferrand Hospital (France) in comparison to C-reactive protein. All newborn infants admitted before 24 h of life (day 0) in the neonatal intensive care unit were included in the study. Newborns (102) were assigned to one of four groups: group 1: non-infected newborns (n = 41); group 2: possibly infected newborns (n = 33); group 3: probably infected newborns (n = 10); group 4: confirmed infections (n = 18 bacterial or fungal infections). C-reactive protein and PCT were determined in the sera at D0, D1, D3 and D8. We determined the optimal cutoff value of PCT using the Receiver Operating Characteristic curves (R.O.C.).

RESULTS

The cutoff value is 1.5 ng/mL at D0 and 10 ng/mL at D1. PCT cutoff value is significantly higher at D1 because of a significant PCT peak on the first day of life independent of any infectious stimulus. Our study shows that at D0 and D1 infected newborn infants had significantly higher mean PCT and C-reactive protein values than non infected newborn infants. C-reactive protein has a better specificity but PCT has better sensitivity and negative predictive value.

CONCLUSION

PCT seems to be an interesting marker of neonatal infections especially during the first 24 h of life even though the mechanism of PCT synthesis remains unclear.

Detection of acute phase response and infection. The role of procalcitonin and C-reactive protein

OBJECTIVE

Established parameters, e.g. C-reactive protein (CRP), do not differentiate specifically enough between patients developing an infection and those exhibiting an acute phase response following cardiac surgery. The objective of this prospective study was to investigate if procalcitonin (PCT) is more helpful than CRP.

METHODS

During a 1-year period, seven out of 563 patients (1.2%) developed systemic infections (group A) after cardiac operations with cardiopulmonary bypass (CPB), and additional eight patients (1.4%) had local wound infections requiring surgical therapy (group B). Blood samples for PCT and CRP measurements were taken preoperatively, at the onset of infection (d1), as well as on the third day (d3), fifth day (d5), and seventh day (d7) following diagnosis of infection. Forty-four randomly selected patients undergoing cardiac surgery with CPB without clinical signs of infection, additional intensive care unit (ICU) management or additional antibiotic treatment served as control (group C) to assess the PCT and CRP contribution to acute phase response. PCT and CRP levels were measured preoperatively, on the first (d1), third (d3) and fifth day (d5) after operation.

RESULTS

At the onset of infection, PCT levels (median interquartile range 25%-75%) increased significantly in group A as compared to baseline values (10.86 (3.28-15.13) ng/ml vs. 0.12 (0.08-0.21) ng/ml), and decreased during treatment to still significantly elevated values on d5 (0.56 (0.51-0.85) ng/ml). CRP levels were significantly elevated on all days investigated with no trend towards normalisation (d1: 164.5 (137-223) mg/l) vs. 1.95 (1.1-2.8) mg/l preoperatively, d5: 181.1 (134-189.6) mg/l. In group B, no increase in PCT levels, but a significant increase of CRP from d1 (165.9 (96.6-181.6) mg/l) vs. 3.7 (2-4.3) mg/l preoperatively) until d5 98 (92.8-226.2) mg/l was detected. In group C, postoperative PCT levels increased slightly but significantly in the absence of infection on d1 (0.46 (0.26-0.77) ng/ml vs. 0.13 (0.08-0.19) ng/ml preoperatively), and d3 (0.37 (0.2-0.65) ng/ml and reached baseline on d5 (0.24 (0.11-0.51) ng/ml)). CRP levels were significantly elevated as compared to baseline on all postoperative days investigated (baseline: 1.75 (0.6-2.9) mg/l, d1: 97.5 (74.5-120) mg/l), d3: 114 (83.05-168.5) mg/l, d5: 51.4 (27.4-99.8) mg/l)). PCT showed a significant correlation to CRP in group A (r =0.48, p < 0.001), a weak correlation in group C (r=0.27, p=0.002) and no correlation in group B. Intergroup comparison revealed a significant difference for PCT between all groups (A>C>B) and significantly higher CRP levels in group A vs. C and in group B vs. C. Thus, the pattern high PCT/high CRP appears to indicate a systemic infection, while low PCT/high CRP indicates either acute phase response or local wound problems, but no systemic infection. The cost for PCT measurements was 5.6-fold higher as compared to CRP.

CONCLUSION

Due to the significant differences in the degree of increase, PCT appears to be useful in discriminating between acute phase response following cardiac surgery with CPB or local problems and systemic infections, with additional CRP-measurement increasing the specificity.

Comparison of procalcitonin (PCT) and C-reactive protein (CRP) plasma concentrations at different SOFA scores during the course of sepsis and MODS

OBJECTIVES: The relation of procalcitonin (PCT) plasma concentrations compared with C-reactive protein (CRP) was analyzed in patients with different severity of multiple organ dysfunction syndrome (MODS) and systemic inflammation. PATIENTS AND METHODS: PCT, CRP, the sepsis-related organ failure assessment (SOFA) score, the Acute Physiology, Age, Chronic Health Evaluation (APACHE) II score and survival were evaluated in 40 patients with systemic inflammation and consecutive MODS over a period of 15 days. RESULTS: Higher SOFA score levels were associated with significantly higher PCT plasma concentrations (SOFA 7-12: PCT 2.62 ng/ml, SOFA 19-24: PCT 15.22 ng/ml) (median), whereas CRP was elevated irrespective of the scores observed (SOFT 7-12: CRP 131 mg/l, SOFT 19-24: CRP 135 mg/l). PCT of non-surviving patients was initially not different from that of survivors but significantly increased after the fourth day following onset of the disease, whereas CRP was not different between both groups throughout the whole observation period. CONCLUSIONS: Measurement of PCT concentrations during multiple organ dysfunction syndrome provides more information about the severity and the course of the disease than that of CRP. Regarding the strong association of PCT and the respective score systems in future studies we recommend evaluation also of the severity of inflammation and MODS when PCT concentrations were compared between different types of disease.

Procalcitonin is a marker of severity of renal lesions in pyelonephritis

OBJECTIVE

In an attempt to differentiate acute pyelonephritis from lower urinary tract infection (UTI), we measured serum procalcitonin levels, a recently described marker of infection. We compared it with other commonly used inflammatory markers and evaluated its ability to predict renal involvement as assessed by dimercaptosuccinic acid (DMSA) scintigraphy.

METHODS

Serum C-reactive protein, leukocyte counts, and procalcitonin levels were measured in 80 children, 1 month to 16 years of age, admitted for suspected pyelonephritis. Renal involvement was assessed by 99mTe-DMSA scintigraphy in the first 5 days after admission. The examination was repeated at least 3 months later if the first result was abnormal.

RESULTS

In lower UTI, the mean procalcitonin (PCT) was 0.38 micrograms/L +/- 0.19 compared with 5.37 micrograms/L +/- 1.9 in pyelonephritis. In these two groups, respectively, leukocyte counts were 10939/mm3 +/- 834 and 17429/mm3 +/- 994, and C-reactive protein (CRP) levels were 30.3 mg/L +/- 7.6 and 120.8 mg/L +/- 8.9. When inflammatory markers were correlated to the severity of the renal lesion as ranked by DMSA scintigraphy, we found a highly significant correlation with plasma levels of PCT, but borderline significance with CRP and none with leukocyte counts. Patients without vesicoureteral reflux had a mean PCT of 5.16 micrograms/L +/- 2.33, which was not significantly different from that in patients with reflux who had a mean PCT of 5.76 micrograms/L +/- 3.49. For the prediction of renal lesions at admission, CRP had a sensitivity of 100% and a specificity of 26.1%. The sensitivity and specificity of PCT were 70.3% and 82.6%, respectively.

CONCLUSION

We conclude that serum PCT levels were increased significantly in children with febrile UTI when renal parenchymal involvement (assessed by DMSA scintigraphy) was present and allowed for prediction of patients at risk of severe renal lesions.

Postoperative plasma concentrations of procalcitonin after different types of surgery

OBJECTIVE

Procalcitonin (PCT) and C-reactive protein (CRP) plasma concentrations were measured after different types of surgery to analyze a possible postoperative induction of procalcitonin (PCT), which might interfere with the diagnosis of bacterial infection or sepsis by PCT.

DESIGN

PCT and CRP plasma levels as well as clinical symptoms of infection were prospectively registered preoperatively and 5 days postoperatively.

SETTING

University hospital, in-patient postoperative care.

PATIENTS

Hundred thirty patients were followed up; 117 patients with a normal postoperative course were statistically analyzed.

INTERVENTIONS

None.

MEASUREMENTS AND RESULTS

PCT concentrations were moderately increased above the normal range in 32 % of patients after minor and aseptic surgery, in 59 % after cardiac and thoracic surgery, and in 95 % of patients after surgery of the intestine. In patients with an abnormal postoperative course, PCT was increased in 12 of 13 patients. CRP was increased in almost all patients.

CONCLUSIONS

Postoperative induction of PCT largely depends on the type of surgery. Intestinal surgery and major operations more often increase PCT, whereas it is normal in the majority of patients after minor and primarily aseptic surgery. PCT can thus be used postoperatively for diagnostic means only when the range of PCT concentrations during the normal course of a certain type of surgery is considered and concentrations are followed up.

Serum procalcitonin rise is only slight in two cases of disseminated aspergillosis

High serum concentrations of procalcitonin (PCT) have been found during bacterial and parasitic infections. This is a report of two cases of disseminated aspergillosis with moderate PCT increase in two 14-year-old girls after bone marrow transplantation (BMT) for myelodysplastic syndrome and Fanconi's anemia, respectively. In contrast, the important rise of serum CRP observed in these patients tends to demonstrate that the synthesis of these two proteins is under different control mechanisms.