The effects of different infectious organisms on platelet counts and platelet indices in neonates with sepsis: is there an organism-specific response?

Early Diagnostic Markers of Late-Onset Neonatal Sepsis

OBJECTIVE

Early diagnosis of nosocomial infections in newborns is a great challenge, because in the initial phase of systemic infection, clinical symptoms are often non-specific, and routinely used hematological markers are not sufficiently informative. The aim of this study was to determine the potential of early inflammatory markers to diagnose late-onset neonatal sepsis-procalcitonin (PCT), interleukin 6 (IL-6), interleukin 8 (IL-8) and endocan (ESM-1).

MATERIAL AND METHODS

A prospective clinical-epidemiological study was conducted in a third-level NICU in Pleven, Bulgaria. Patients with suspected late-onset sepsis and healthy controls were tested. A sandwich ELISA method was used to measure the serum concentrations of biomarkers.

RESULTS

Sixty newborns were included, of which 35% symptomatic and infected, 33.3% symptomatic but uninfected and 31.7% asymptomatic controls. The mean values of PCT, IL-6, I/T index and PLT differ significantly in the three groups. For ESM-1, IL-8 and CRP, the difference was statistically insignificant. The best sensitivity (78%) and negative predictive value (84%) was found for IL-6. The combinations of PCT + IL-6 and PCT + IL-6+ I/T+ PLT showed very good diagnostic potential.

CONCLUSION

The introduction into the routine practice of indicators such as PCT and IL-6 may provide an opportunity to promptly optimize the diagnostic and therapeutic approach to LOS.

Frequency and Severity of Thrombocytopenia in Neonatal Sepsis

Background

Neonatal sepsis includes numerous systemic illnesses such as septicemia, meningitis, urinary tract infections, and pneumonia. In developing countries, the major reason for neonatal mortality is septicemia, which accounts for almost 50% of overall deaths. Thrombocytopenia is one of the most common hematological problems during the neonatal period, affecting the majority of sufferers admitted to the neonatal intensive care unit (NICU). The aim of our study was to find the frequency of thrombocytopenia and its severity in neonates with sepsis.

Methods

The study was conducted at the Department of Hematology at Khyber Medical University, Peshawar, Pakistan. A total of 170 neonates with an age of fewer than 28 days, both genders, and positive blood cultures were included in the study using a non-probability consecutive sampling technique. Data was recorded in predesigned questionnaires after taking informed consent. Data were recorded and analyzed using SPSS version 26 (IBM Corporation, Armonk, NY, USA).

Results

Of the 170 neonates, 104 (61.2%) were males, with a mean age of 12.12±8.88 days. The majority of the babies 73 (42.9%) were in the age group of 0-7 days. Most of the neonates 72 (42.4%) were born via normal vaginal delivery (NVD). Of the neonates, 117 (68.82%) presented with fever, and 105 (61.76%) were reluctant to feed. Furthermore, 65.29% of the neonates had thrombocytopenia, of which 34 (20%) had mild, 43 (25.3%) had moderate, and 34 (20%) had severe thrombocytopenia. In neonates with positive blood culture, the platelet level was low (p<0.001). In the case of gram-negative organisms, the level of platelets was lower as compared to gram-positive organisms (p<0.001).

Conclusion

Sepsis is still a common cause of newborn thrombocytopenia. The fact that it is present in more than half of all culture-positive sepsis episodes indicates the severity of the condition. This condition is further defined by higher percentages of early-onset gram-negative septicemia compared to gram-positive sepsis.

Platelets in pediatric and neonatal sepsis: novel mediators of the inflammatory cascade

Sepsis, a dysregulated host response to infection, has been difficult to accurately define in children. Despite a higher incidence, especially in neonates, a non-specific clinical presentation alongside a lack of verified biomarkers has prevented a common understanding of this condition. Platelets, traditionally regarded as mediators of haemostasis and thrombosis, are increasingly associated with functions in the immune system with involvement across the spectrum of innate and adaptive immunity. The large number of circulating platelets (approx. 150,000 cells per microlitre) mean they outnumber traditional immune cells and are often the first to encounter a pathogen at a site of injury. There are also well-described physiological differences between platelets in children and adults. The purpose of this review is to place into context the platelet and its role in immunology and examine the evidence where available for its role as an immune cell in childhood sepsis. It will examine how the platelet interacts with both humoral and cellular components of the immune system and finally discuss the role the platelet proteome, releasate and extracellular vesicles may play in childhood sepsis. This review also examines how platelet transfusions may interfere with the complex relationships between immune cells in infection. IMPACT: Platelets are increasingly being recognised as important "first responders" to immune threats. Differences in adult and paediatric platelets may contribute to differing immune response to infections. Adult platelet transfusions may affect infant immune responses to inflammatory/infectious stimuli.

Platelet Indices and Their Kinetics Predict Mortality in Patients of Sepsis

Platelet indices are inexpensive, easily accessible parameters and potentially useful prognostic indicators in sepsis. In this study we explore the differences in platelet indices and their kinetics between sepsis survivors and non-survivors. A retrospective cohort-study of 97 cases of culture-positive sepsis at a tertiary-care center in North India. Demographics, clinical and laboratory parameters at admission were assessed. Platelet count (PLT), mean-platelet-volume (MPV), platelet-distribution-width (PDW) and plateletcrit (PCT) on admission, and third, fifth and last days of hospitalization were analyzed. Fractional change in platelet indices (ΔMPV_72h, ΔPDW_72h, ΔPCT_72h, and ΔPLT_72h) by day-3 were calculated. Unpaired and paired t-tests were used to compare survivors with non-survivors, and to study the change in platelet indices with time. Logistic regression was used for multivariate analysis. ROC-curves and optimum cut-offs to predict mortality were obtained. There were 64 survivors. Non-survivors had significantly higher ΔMPV_72h, ΔPDW_72h, day-1 MPV and PDW, and lower ΔPLT_72h. MPV and PDW increased, and PLT decreased with time among non-survivors. Trends were reversed in survivors. Only MPV and PDW showed significant change by day-3. Both were independent predictors of mortality on multivariate analysis, alongside ΔMPV_72h and ΔPLT_72h. On ROC analysis, MPV, PDW, ΔMPV_72h, ΔPDW_72h and ΔPLT_72h effectively predicted mortality. Cut-off for MPV was 10.25 fL (sensitivity = 93.9%, specificity = 60.9%), and PDW, 12.6% (sensitivity = 84.8%, specificity = 51.6%). A rise in MPV and a fall in PLT was associated with mortality in this study. MPV and PDW values at admission are effective predictors of mortality and may be used in conjunction with traditional parameters.

Thrombocytopenia in neonatal sepsis: Incidence, severity and risk factors

Objectives

Thrombocytopenia is a frequent problem in neonatal sepsis and is among the most predictive, independent risk factors for sepsis-associated mortality. This study aims to clarify the occurrence, severity and duration of thrombocytopenia in neonatal sepsis.

Study design

A cohort study was carried out among all neonates with proven culture positive sepsis that were admitted to a tertiary NICU between 2006 and 2015 (n = 460). The occurrence, severity and duration of thrombocytopenia were recorded, as well as major bleedings and potential risk factors for mortality in neonatal sepsis.

Results

Sepsis was diagnosed in 460 of 6551 neonates (7%). Severe thrombocytopenia (platelets ≤50*10⁹/L) occurred in 20% (92/460) of septic neonates. The median time for platelets to rise >100*10⁹ was 6.0 days (interquartile range 4.0–7.0). On multivariate analysis, maternal hypertension, intravascular thrombosis and Gram negative (as opposed to Gram positive) sepsis were independently associated with thrombocytopenia in neonatal sepsis. In severe thrombocytopenia, 10% (9/92) suffered a severe IVH, compared to 5% (20/356) in neonates with platelets >50*109/L (p = 0.125). 10% (9/92) suffered a pulmonary hemorrhage, compared to 2% (9/368) in neonates with platelets >50*109/L (p = 0.001). On multivariate analysis, thrombocytopenia and Gram negative (as opposed to Gram positive) sepsis were independently associated with neonatal mortality.

Conclusions

Thrombocytopenia is independently associated with maternal hypertension, intravascular thrombosis and Gram negative sepsis. Thrombocytopenia in neonatal sepsis increases the risk of mortality nearly four-fold, with another six-fold increase in mortality in case of Gram negative sepsis.

Platelet indices in neonatal sepsis: A review

Thrombocytopenia is a common hematological abnormality in neonates with sepsis. The autoanalyzers now-a-days readily provide platelet indices along with platelet counts without any additional cost. However these indices are not given proper weightage often. The important platelet indices available for clinical utility include mean platelet volume (MPV), platelet distribution width and plateletcrit that are related to morphology and proliferation kinetics of platelets. Studies in adult patients reported their role in the diagnosis of severe sepsis and prognosis of adverse clinical outcomes including mortality. Abnormal MPV can aid diagnosing the cause of thrombocytopenia. Low MPV associated with thrombocytopenia has been found to result in clinical bleeding. Other indices, however, are less studied. The studies addressing the importance of these platelet indices in neonatal sepsis are limited. The current review gives an overview of potential utility of important platelet indices in neonatal sepsis.

Reduction in mean platelet volume in children with acute bronchiolitis

AIM

Platelets which are known to play a role in inflamation change their shapes when they are activated and this change is reflected in mean platelet volume and platelet distribution width values. Therefore, the mean platelet volume and platelet distribution width values are considered to be beneficial parameters for the diagnosis and treatment of many inflammatory diseases. The aim of the study was to evaluate platelet volume indices in children with acute bronchiolitis.

MATERIAL AND METHODS

A total of 514 infants who were below the age of 2 years old were evaluated in this study. Three hundred thirteen of these infants were diagnosed with acute bronchiolitis patients and 201 were healthy children. The patients were separated into four groups as mild, moderate, severe bronchiolitis and the control patient group. The groups were evaluated in terms of significant differences in the values of mean platelet volume and platelet distribution width. A p value of <0.05 was considered statistically significant for all results.

RESULTS

The mean platelet volume was found to be 6.8±0.6 fL in the patients with mild bronchiolitis attack, 6.7±0.6 fL in the patients with moderate bronchiolitis attack, 6.5±0.5 fL in the patients with severe bronchiolitis attack and 7.3±1.1 fL in the control group. The mean platalet volume was statistically significantly lower in the mild, moderate and severe bronchiolitis attack groups compared to the control group (p=0.000). The platelet distribution width was found to be 17.2%±0.83 in the mild bronchiolitis attack group, 17.1%±0.96 in the moderate bronchiolitis attack group, 17.3%±0.87 in the severe bronchiolitis attack group and 16.9±1.6% in the control patient group. This difference was not statistically significant (p=0.159). The platelet count was statistically significantly higher in the mild, moderate and severe bronchiolitis attack groups compared to the control group (p=0.000).

CONCLUSIONS

The mean platalet volume is decreased in patients with acute bronchiolitis. It is not a useful criterion in determining the severity of bronchiolitis attack. It is important that clinicians evaluating hemogram results to also interprete this variable.

The impact of various platelet indices as prognostic markers of septic shock

Introduction

Platelet indices, including mean platelet volume (MPV), are readily available blood tests, although their prognostic value in patients with septic shock has not been fully explored. Current evidence has found contradictory results. This study aims to explore the behavior of platelet indices in septic shock and their clinical prognostic value.

Methods

Charts of septic shock patients from January to December 2012 in a tertiary medical center in Northern China were reviewed retrospectively. Platelet indices were recorded during the first five consecutive days after admission, as well as the penultimate and the last day of hospital stay. The data were compared between surviving and non-surviving patients.

Results

A total of 124 septic shock patients were enrolled. Thirty-six of the patients survived and 88 of them expired. MPV in the non-survivor group was higher than that of the survivor group, especially on the last day. PDW and PLCR showed increased trends, while PCT and PLT decreased in the non-survivor group. Among the PLT indices, MPV had the highest area under the receiver operating characteristic curve (0.81) with a precision rate of 75.6% at a cut-off of 10.5.Compared with other more usual septic shock prognostic markers, MPV is second only to lactate for the highest area under the curve.

Conclusion

A statistically significant difference was seen between survivors and non-survivors for platelet indices which make them easily available and useful prognostic markers for patients in septic shock.

Thrombocyte and Erythrocyte Indices in Sepsis and Disseminated Intravascular Coagulation

Sepsis is the inflammatory response against infection. The existence of DIC during sepsis indicates a poor prognosis and coagulation abnormalities and thrombocytopenia may exist. The aim of this study was to investigate platelet and erythrocyte indices in sepsis patients with DIC and without DIC. In both groups coagulation tests, platelet count and indices, erythrocyte count and indices were retrospectively analysed. In the sepsis plus DIC patients the prothrombin time and D-dimer values were found significantly higher and fibrinogen, platelet and plateletcrit were found significantly lower than in the sepsis without DIC group. The analysis of mean platelet volume, platelet distribution width, erythrocyte count and indices revealed no significant differences between the two groups. These results showed us that the depression of bone marrow in septic patients with DIC and without DIC did not differ. The activation of the coagulation system might probably be the cause of thrombocyte depletion in DIC.

Organism-specific platelet response and factors affecting survival in thrombocytopenic very low birth weight babies with sepsis

OBJECTIVE

To study organism-specific platelet response and factors affecting survival in thrombocytopenic very low birth weight (VLBW) babies with sepsis.

STUDY DESIGN

Very low birth weight babies (birth weight <1500 g) admitted to a single level-three intensive care unit from January 2000 to December 2005 were prospectively evaluated for sepsis by rapid screen test, blood counts and blood culture. In thrombocytopenic babies, organism-specific platelet response and its effect on various platelet parameters were evaluated. In addition, morbidity, mortality and factors affecting survival were studied.

RESULT

Sepsis was diagnosed in 230 of 620 (37%) patients. Gram-positive sepsis occurred in 20% (46/230), Gram-negative in 71% (164/230) and fungal in 8.6% (20/230) of patients. Thrombocytopenia was observed in 67% (155/230) of babies. The frequency and duration of thrombocytopenia were more with Gram-negative and fungal infections. The incidence of persistent bacteremia, multiorgan failure and death was more in thrombocytopenic neonates (P<0.01). The incidence of multiorgan failure and death was directly related to the duration of thrombocytopenia. On multiple logistic regression analysis, poor prognostic factors include a high SNAP score at admission, a severe drop in platelet count at onset of sepsis, a low platelet nadir, a prolonged duration of thrombocytopenia, a need for platelet transfusion, less number of days off ventilation and a prolonged stay in the hospital.

CONCLUSION

In thrombocytopenic VLBW babies with sepsis, organism-specific platelet response is seen. In addition, persistent bacteremia, multiorgan failure and death are more in these babies, and survival decreases with the increased severity and duration of thrombocytopenia, with prolonged ventilation and increased need for platelet transfusions.