Influence of perinatal conditions on C-reactive protein production

Serum C-Reactive Protein Levels in Healthy Neonates in Different Gestational and Postnatal Ages

There is paucity of normative data on serum C-reactive protein (CRP) in neonates. In Part I of study, we compared CRP in healthy neonates (from 28°/7 weeks to 416/7 weeks of gestation) between various gestational and postnatal age groups in first week. We planned recruitment of 50 participants each in 'term', 'late preterm' and 'moderate-to-very preterm' groups, equally divided in '24-95 h' and '96-168 h' postnatal age sub-groups. In Part II of study, we assayed CRP weekly in moderate-to-very preterm neonates until day 28 to evaluate its trend. Among 154 subjects, term neonates had higher CRP, with highest values among term infants aged 24-95 h. Barring postnatal age, maternal/perinatal factors did not affect CRP levels. CRP did not change significantly over 28 days in moderate-to-very preterm neonates. In conclusion, serum CRP in healthy neonates is highest among term infants aged 24-95 h and does not vary significantly in the first month of life among moderate-to-very preterm infants.

The diagnostic utility of procalcitonin, interleukin-6 and interleukin-8, and hyaluronic acid in the Norwegian consensus definition for early-onset neonatal sepsis (EONS)

Introduction

A key challenge in identifying serious bacterial infection in new born infants is the nonspecific clinical presentation of early-onset neonatal sepsis (EONS). Routinely used C-reactive protein, white blood cell count, and platelets are nonspecific. We assessed the diagnostic utility of single biomarkers or combinations of procalcitonin (PCT), interleukin (IL)-6, IL-8, and hyaluronic acid (HA) in newborn infant with EONS, and in human umbilical cord blood (HUCB) from deliveries with chorioamnionitis.

Materials and methods

Blood was collected from term infants with strictly defined EONS (group 1, n=15), healthy term infants (group 2, n=15), and the umbilical vein from pregnancies with suspected chorioamnionitis (group 3, n=8), and from healthy pregnancies with no signs of infection (group 4, n=15).

Results

Neonatal plasma PCT and IL-8 showed good predictive value (90% and 83%) for EONS, and the combination of IL-6 or HA with PCT increased the predictability to 87% and 90%, respectively. PCT, IL-6, IL-8, and HA were 8.4-, 4.5-, 3.6-, and 1.9-fold higher when compared with plasma levels in noninfected neonates. PCT, IL-6, and IL-8 in HUCB predicted chorioamnionitis and fever in the delivering mother (89%, 83%, and 72%, respectively). HA was a poor predictor (59%), but its predictability increased in combination with PCT, IL-8, or IL-6. In HUCB from chorioamnionitic deliveries, IL-6, IL-8, and PCT were 23-, 14-, and 2.4-fold higher, respectively, when compared with HUCB from healthy deliveries. There was no correlation between C-reactive protein, white blood cell, and platelet count with PCT, IL-6, IL-8, or HA.

Conclusion

In neonates that fulfilled the Norwegian consensus definition of neonatal sepsis, PCT, IL-6, and IL-8, but not HA, have the potential to improve our management of neonates at risk. Except for PCT and IL-8, both with a predictability of >80% in neonatal plasma, combinations of biomarkers increased the predictability for EONS and chorioamnionitis.

Management of the neonate at risk for early-onset Group B streptococcal disease (GBS EOD): new paediatric guidelines in Belgium

Despite group B streptococcal (GBS) screening in late pregnancy and intrapartum antimicrobial prophylaxis, early-onset sepsis in neonates remains a common source of neonatal morbidity and mortality especially in preterm neonates. The identification of neonates with early-onset sepsis is usually based on perinatal risk factors. Clinical signs are aspecific and laboratory tests are not sensitive. Therefore, many clinicians will overtreat at-risk infants. Inappropriate treatment with antibiotics increases the risk for late-onset sepsis, necrotizing enterocolitis, mortality, and prolongs hospitalisation and costs. In 2003, the Belgian Health Council published guidelines for the prevention of perinatal GBS infections. This report presents the Belgian paediatric management guidelines, which have been endorsed by the Belgian and Flemish societies of neonatology and paediatrics. The most imported changes in the 2014 guidelines are the following: recommendations for a lumbar puncture; clarification of normal spinal fluid parameters and blood neutrophil indices corrected for gestation age; specific timing for diagnostic testing after birth; no indication for diagnostic testing in asymptomatic newborns unless additional risk factors; a revised algorithm for management of neonates according to maternal and neonatal risk factors; and premature infants described as those below 35 weeks instead of 37 weeks. The guidelines were made on the basis of the best evidence and on expert opinion when inadequate evidence exists.

Does polycythemia affect interleukin-6 response pattern in early postnatal period?

INTRODUCTION

Neonatal polycythemia may result in increased cytokine production. We aimed to investigate whether polycythemia and partial exchange transfusion (PET) affect interleukin-6 (IL-6) response pattern in early neonatal period.

METHODS

Ninety-four newborns, 57 with polycythemia (Group 1) and 37 as control group (Group 2) were enrolled in the study. PET was performed at 4-6 hr following birth in the first group. Blood levels of IL-6 were measured at 2-4 hr following birth; measurements were repeated at 6 and 24 hr after PET in newborns with polycythemia and at similar hours in Group 2. In Group 1, two patients (3.5%) who were diagnosed with proven sepsis excluded from the study.

RESULTS

Both initial and the last IL-6 levels were higher in Group 1 (21.7; 5.5-190 pg/ml and 18.3; 2.7-92.4 pg/ml) than those of the controls (8.4; 0.2-47.8 pg/ml and 8.6; 2.0-21.0 pg/ml) (P=0.001 for both comparisons). In Group 1, IL-6 levels increased at 6 hr after PET and decreased thereafter. IL-6 showed the same pattern in the control group. IL-6 levels were higher than >70 pg/ml in two (3.6%), seven (12.7%), and two (3.6%) subjects during three evaluation steps, respectively. Neither clinical nor proven sepsis was subsequently detected in any of these subjects. IL-6 levels were within the acceptable values in Group 2.

CONCLUSION

IL-6 levels seem to be high in newborns with polycythemia during the first days of life, although they rarely exceed maximum acceptable levels. The pattern of IL-6 response might be taken into account to optimize its use in the diagnosis of early-onset neonatal sepsis.

Early intratracheal instillation of budesonide using surfactant as a vehicle to prevent chronic lung disease in preterm infants: a pilot study

OBJECTIVE

Budesonide is an inhaled steroid with a strong topical effect but with minimal systemic effects; it has been effectively delivered to animal lungs using surfactant as a vehicle. The purposes of this study were to determine whether early intratracheal instillation of budesonide using surfactant as a vehicle would improve pulmonary status, reduce mortality, and reduce chronic lung disease morbidity.

PATIENTS AND METHODS

We conducted a prospective, randomized blind trial in 116 very low birth weight infants (< 1500 g) who had severe radiographic respiratory distress syndrome and required mechanical ventilation with fraction of inspired oxygen > or = 0.6 shortly after birth: 60 were in the treated group (intratracheal instillation of a mixture of 0.25 mg/kg of budesonide and 100.00 mg/kg of survanta, every 8 hours) and 56 were in the control group (100 mg/kg of survanta only, every 8 hours). The end point assessment was the number of infants who would die or develop chronic lung disease at 36 weeks' postconceptional age.

RESULTS

Infants in the treatment group required significantly lower mean airway pressure on day 1 and day 3 and had significantly lower oxygen index and PCO(2) during the first 3 days than infants in the control group. More infants were extubated in the treatment group than controls at 1 and 2 weeks. The combined outcome of deaths or chronic lung disease was significantly lower in the treatment group than in the control group (19 of 60 vs 34 of 56). No clinically significant adverse effects were observed during the study.

CONCLUSIONS

This pilot study indicated that early postnatal intratracheal instillation of budesonide using surfactant as vehicle significantly improved the combined outcome of death or chronic lung disease in small premature infants without causing immediate adverse effects. The results are encouraging, and a large sample multicenter trial is warranted.

Procalcitonin as a screening test for late-onset sepsis in preterm very low birth weight infants

OBJECTIVE

To compare the utility of procalcitonin (PCT) vs C-reactive protein (CRP) as indicators of late-onset neonatal sepsis in very low birth weight (VLBW) infants.

METHODS

PCT and CRP levels were measured in VLBW infants with suspected sepsis and controls. Comparisons were made between infected vs noninfected infants. Using cutoff values of 0.5 and 1.0 ng/ml for PCT and 0.8 mg/dl for CRP, sensitivity, specificity, positive and negative predictive values were calculated to evaluate these assays as potential predictors of late-onset sepsis.

RESULTS

A total of 67 infants were evaluated. Mean PCT levels were significantly higher in the infected group (5.41 ng/ml) compared to the noninfected group (0.43 ng/ml) (p < 0.001). At a cut off value of 0.5 ng/ml, the sensitivity of PCT was 97%, whereas that of CRP was 73% in predicting late-onset sepsis. At a PCT cutoff of 1.0 ng/ml, sensitivities of PCT and CRP were similar (72% each).

CONCLUSION

PCT (0.5 ng/ml) is more sensitive than CRP in predicting late-onset sepsis in VLBW infants.

Clinical microbiology of bacterial and fungal sepsis in very-low-birth-weight infants

Twenty percent of very-low-birth-weight (<1500 g) preterm infants experience a serious systemic infection, and despite advances in neonatal intensive care and antimicrobials, mortality is as much as threefold higher for these infants who develop sepsis than their counterparts without sepsis during their hospitalization. Outcomes may be improved by preventative strategies, earlier and accurate diagnosis, and adjunct therapies to combat infection and protect the vulnerable preterm infant during an infection. Earlier diagnosis on the basis of factors such as abnormal heart rate characteristics may offer the ability to initiate treatment prior to the onset of clinical symptoms. Molecular and adjunctive diagnostics may also aid in diagnosing invasive infection when clinical symptoms indicate infection but no organisms are isolated in culture. Due to the high morbidity and mortality, preventative and adjunctive therapies are needed. Prophylaxis has been effective in preventing early-onset group B streptococcal sepsis and late-onset Candida sepsis. Future research in prophylaxis using active and passive immunization strategies offers prevention without the risk of resistance to antimicrobials. Identification of the differences in neonatal intensive care units with low and high infection rates and implementation of infection control measures remain paramount in each neonatal intensive care unit caring for preterm infants.

Inflammatory mediators in perinatal asphyxia and infection

AIM

To determine serum levels of interleukin-6 (IL-6), IL-1beta, tumor necrosis factor-alpha (TNF-alpha), soluble intercellular adhesion molecule-1 (sICAM-1) and C-reactive protein (CRP) in asphyxiated neonates and compare these inflammatory factors with those found in neonates with perinatal infection.

METHODS

88 neonates were studied, of whom 36 were asphyxiated, 18 were infected and the remaining 34 were controls. Peripheral blood samples were obtained on the 1st, 3rd and 5th postnatal days.

RESULTS

Cytokines IL-6 and IL-1beta as well as sICAM-1 serum levels did not differ between asphyxiated and infected neonates; however, at most time periods, their values were significantly higher than controls. TNF-alpha was similar in the three groups of neonates. CRP serum values were significantly higher in the infected neonates than in the asphyxiated or control subjects. Among the 54 asphyxiated and infected neonates, 15 were considered as severe cases and 39 as mild. The severe cases, at most time periods, had significantly higher IL-6, IL-1beta and sICAM-1 levels compared with the mild ones. Through receiver operating characteristic curves the cut-off points, sensitivities, and specificities for distinguishing neonates at risk or at high risk for brain damage were established.

CONCLUSION

Similar increases in serum levels of IL-6, IL-1beta and sICAM-1 were found in perinatally asphyxiated and infected neonates. As these increases correlated with the severity of the perinatal insults, neonates at high risk for brain damage might be detected.

C-reactive protein, interleukin-6, and procalcitonin in the immediate postnatal period: influence of illness severity, risk status, antenatal and perinatal complications, and infection

BACKGROUND

Studies of the diagnostic accuracy of most laboratory tests for early-onset neonatal sepsis have yielded variable results. We investigated whether some of this variation might be attributable to differences in population baseline severity and risk status as well as to specific ante- and perinatal variables, independent of the presence of neonatal infection.

METHODS

The Score for Neonatal Acute Physiology (SNAP) was used to define illness severity, with SNAP Perinatal Extension (SNAP-PE) used to define the combined physiologic and perinatal mortality risk. A total of 134 ill newborns (19 with early-onset infection and 115 with no infection) were available for simultaneous analysis of the association of SNAP, SNAP-PE, and maternal and perinatal variables with C-reactive protein (CRP), interleukin-6 (IL-6), and procalcitonin (PCT) concentrations at birth and at 24 and 48 h of life.

RESULTS

Early-onset neonatal infection was associated with significant increases in CRP, IL-6, and PCT concentrations at all three time points, independent of illness severity. However, among babies without infection, higher SNAP and SNAP-PE scores were associated with higher IL-6 concentrations at birth. Certain maternal or perinatal variables altered IL-6 and PCT values in the infected as well as in the uninfected neonates. However, if different cutoff points were used at any of the three neonatal ages, PCT sensitivity and specificity were greater than those of CRP or IL-6.

CONCLUSIONS

Illness severity and risk status are unlikely to interfere with the use of CRP and PCT for detection of early-onset neonatal sepsis. In contrast, the diagnostic value of IL-6 at birth may be altered by physiologic severity and risk indexes. The reliability of CRP, IL-6, and PCT for the diagnosis of early-onset neonatal infection requires specific cutoff values for each evaluation time point over the first 48 h of life.

Serial Measurements of C-Reactive Protein and Interleukin-6 in the Immediate Postnatal Period: Reference Intervals and Analysis of Maternal and Perinatal Confounders

Background: There is a wide range of reported sensitivities and specificities for C-reactive protein (CRP) and interleukin-6 (IL-6) in the detection of early-onset neonatal infection. This prompted us to assess reference intervals for CRP and IL-6 during the 48-h period immediately after birth and to identify maternal and perinatal factors that may affect them.

Methods: CRP and IL-6 values were prospectively obtained for 148 healthy babies (113 term, 35 near-term) at birth and at 24 and 48 h of life, and from their mothers at delivery.

Results: Upper reference limits for CRP at each neonatal age were established. At birth, CRP was significantly lower than at 24 and 48 h of life. Rupture of membranes ≥18 h, perinatal distress, and gestational hypertension significantly affected the neonatal CRP dynamics, but at specific ages. There was no correlation between CRP concentrations in mothers and their offspring at birth. The IL-6 values observed in the delivering mothers and in their babies at all three neonatal ages were negatively associated with gestational age. In the immediate postnatal period, IL-6 dynamics for term babies were significantly different from those for near-term babies. Maternal IL-6 concentrations correlated with babies’ IL-6 concentrations only for term deliveries. Apgar score had a significant effect on babies’ IL-6 values at birth.

Conclusions: The patterns of CRP and IL-6 responses in the healthy neonate should be taken into account to optimize their use in the diagnosis of early-onset neonatal sepsis.

Use of C-reactive protein to guide duration of empiric antibiotic therapy in suspected early neonatal sepsis

BACKGROUND

Serial C-reactive protein (CRP) measurements have been shown to be useful for guiding duration of antibiotic therapy in neonates. This study sought to determine whether this is a safe and practical approach in a developing country.

METHODS

The study was conducted at the Johannesburg Hospital between September 15, 1998, and January 15, 1999. Subjects included all neonates evaluated for suspected sepsis in the first 24 h of life who had negative initial and repeat CRP values (< or = 10 mg/l) [corrected]. Repeat CRP measurements were performed between 24 and 48 h after birth. Antibiotic therapy was stopped in these infants at 24 to 48 h, and they were observed until 72 h, when the final blood culture results were available. The number of positive blood cultures in this group was determined.

RESULTS

The repeat CRP estimation correctly identified 99 of 100 infants in the study as not requiring further antibiotic therapy (negative predictive value, 99%; 95% confidence intervals, 95.6 to 99.97%). The 1 infant with a positive blood culture was premature with a gestational age of 31 weeks. Eight babies required repeat evaluation for suspected sepsis, 4 presented on Day 3 to 4 and one of these babies died. All these neonates were of < or =33 weeks gestation.

CONCLUSION

The use of serial CRP measurements to guide antibiotic therapy is a safe and practical approach in neonates with suspected sepsis in a developing country.

Serial serum C-reactive protein levels in the diagnosis of neonatal infection

OBJECTIVE

To evaluate serial serum C-reactive protein (CRP) levels for diagnosis of neonatal infection.

SETTING

A regional intensive care nursery and two community intensive care nurseries.

METHODS

All neonates treated for suspected bacterial infection were prospectively evaluated using a standardized clinical pathway. Infants were categorized as having proven sepsis (bacteria isolated from blood, cerebrospinal fluid, or urine culture), probable sepsis (clinical and laboratory findings consistent with bacterial infection without a positive culture), or no sepsis (findings not consistent with sepsis), without consideration of CRP levels. Infants whose blood cultures yielded skin flora but who demonstrated no other signs of bacterial infection were not considered to have sepsis. CRP levels were determined at the initial evaluation and on each of the next two mornings. Sensitivity, specificity, predictive values, and likelihood ratios were calculated for the first (CRP #1), second (CRP #2), higher of the second and third (CRP #2 and #3), or highest of all three CRP levels (CRP x 3).

RESULTS

Sepsis was suspected within the first 3 days after birth in 1002 infants (early-onset) and on 184 occasions in 134 older infants (late-onset). There were 20 early-onset and 53 late-onset episodes of proven sepsis, and 74 early-onset and 12 late-onset episodes of probable sepsis. CRP #1 had sensitivities of 39.4% and 64.6% for proven or probable sepsis and 35.0% and 61.5% for proven sepsis in early-onset and late-onset episodes, respectively. CRP levels on the morning after the initial evaluation (CRP #2) had higher sensitivities (92. 9% and 85.0% for proven or probable sepsis and 78.9% and 84.4% for proven sepsis in early-onset and late-onset episodes, respectively), and normal results were associated with lower likelihoods of infection (likelihood ratios for normal results of 0.10 and 0.19 for proven or probable sepsis and 0.27 and 0.21 for proven sepsis, in early-onset and late-onset episodes, respectively). Three serial serum CRP levels had sensitivities of 97.8% and 98.1% for proven or probable sepsis and 88.9% and 97.5% for proven sepsis in early-onset and late-onset episodes, respectively. The negative predictive values for CRP x 3 were 99.7% and 98.7% for both proven or probable sepsis and for proven sepsis in early-onset and late-onset episodes, respectively. A CRP level obtained at the time of the initial evaluation can be omitted without significant loss of sensitivity or negative predictive value: the sensitivities of CRP #2 and #3 were 97.6% and 94.4% for proven or probable sepsis and 88.9% and 96.4% for proven sepsis in early-onset and late-onset episodes, respectively; negative predictive values were 99.7% both for proven and for proven or probable early-onset sepsis, 97.6% for proven or probable late-onset infection, and 98.8% for proven late-onset infection. Serial normal CRP levels were associated with a markedly reduced likelihood of infection as compared with that in the entire population before testing, with likelihood ratios ranging from 0.03 to 0.16 for the various subgroups. Maximum CRP levels >3 mg/dL had positive predictive values >20% for proven or probable early-onset infections and for proven or probable and proven late-onset infections, but only those >6 mg/dL had such a high positive predictive value for proven early-onset sepsis.

CONCLUSIONS

Serial CRP levels are useful in the diagnostic evaluation of neonates with suspected infection. Two CRP levels <1 mg/dL obtained 24 hours apart, 8 to 48 hours after presentation, indicate that bacterial infection is unlikely. The sensitivity of a normal CRP at the initial evaluation is not sufficient to justify withholding antibiotic therapy. The positive predictive value of elevated CRP levels is low, especially for culture-proven early-onset infections.

Neutrophil CD11b expression as a diagnostic marker for early-onset neonatal infection

OBJECTIVES

To determine whether neutrophil surface expression of CD11b predicts early-onset infection or suspected infection in at-risk infants.

STUDY DESIGN

CD11b expression on peripheral blood neutrophils was determined by flow cytometry of whole blood samples. Blood (0.1 ml) was obtained from a convenience sample of at-risk infants admitted to the neonatal intensive care unit, stained with antibodies detecting CD11b and CD15, chilled, and analyzed within 8 hours. Blood for culture, blood counts, and C-reactive protein (CRP) determination was obtained simultaneously. Subjects were grouped on the basis of culture results and clinical signs, and investigators were blinded to CD11b level.

RESULTS

Of 106 subjects, seven had positive bacterial or viral cultures ("confirmed infection"), 17 had clinical signs of infection but negative cultures ("suspected infection"), and 82 had negative cultures and no clinical signs ("no infection"). Neutrophil CD11b was elevated in all infants with confirmed infection, 94% with suspected infection, and none with no infection. The negative and positive predictive values, sensitivity, and specificity were 100%, 99%, 96%, and 100%, respectively, for diagnosis of neonatal infection at initial evaluation. CD11b levels correlated with peak CRP (r2 = 0.76, p < 0.0001); however, CD11b was elevated at the time of admission in all five infants with proven bacterial infection, whereas CRP was normal until the second day in the neonatal intensive care unit in three of these five. Both infants with positive viral cultures had elevated CD11b, but the CRP levels remained within normal limits. The negative predictive value of neutrophil CD11b for identifying suspected or confirmed infection was 99%.

CONCLUSION

This assay for neutrophil CD11b is a promising test for exclusion of early-onset neonatal infection. If validated prospectively, this assay may reduce hospital and antibiotic use in the population of neonates at risk for early-onset infection.

Early postnatal dexamethasone therapy for the prevention of chronic lung disease in preterm infants with respiratory distress syndrome: a multicenter clinical trial

OBJECTIVES

To study whether early postnatal (<12 hours) dexamethasone therapy reduces the incidence of chronic lung disease in preterm infants with respiratory distress syndrome.

MATERIALS AND METHODS

A multicenter randomized, double-blind clinical trial was undertaken on 262 (saline placebo, 130; dexamethasone, 132) preterm infants (<2000 g) who had respiratory distress syndrome and required mechanical ventilation shortly after birth. The sample size was calculated based on the 50% reduction in the incidence of chronic lung disease when early dexamethasone is used, allowing a 5% chance of a type I error and a 10% chance of a type II error. For infants who received dexamethasone, the dosing schedules were: 0.25 mg/kg/dose every 12 hours intravenously on days 1 through 7; 0.12 mg/kg/dose every 12 hours intravenously on days 8 through 14; 0.05 mg/kg/dose every 12 hours intravenously on days 15 through 21; and 0. 02 mg/kg/dose every 12 hours intravenously on days 22 through 28. A standard protocol for respiratory care was followed by the participating hospitals. The protocol emphasized the criteria of initiation and weaning from mechanical ventilation. The diagnosis of chronic lung disease based on oxygen dependence and abnormal chest roentgenogram was made at 28 days of age. To assess the effect of dexamethasone on pulmonary inflammatory response, serial tracheal aspirates were assayed for cell counts, protein, leukotriene B4, and 6-keto prostaglandin F1alpha. All infants were observed for possible side effects, including hypertension, hyperglycemia, sepsis, intraventricular hemorrhage, retinopathy of prematurity, cardiomyopathy, and alterations in calcium homeostasis, protein metabolism, and somatic growth.

RESULTS

Infants in the dexamethasone group had a significantly lower incidence of chronic lung disease than infants in the placebo group either judged at 28 postnatal days (21/132 vs 40/130) or at 36 postconceptional weeks (20/132 vs 37/130). More infants in the dexamethasone group than in the placebo group were extubated during the study. There was no difference between the groups in mortality (39/130 vs 44/132); however, a higher proportion of infants in the dexamethasone group died in the late study period, probably attributable to infection or sepsis. There was no difference between the groups in duration of oxygen therapy and hospitalization. Early postnatal use of dexamethasone was associated with a significant decrease in tracheal aspirate cell counts, protein, leukotriene B4, and 6-keto prostaglandin F1alpha, suggesting a suppression of pulmonary inflammatory response. Significantly more infants in the dexamethasone group than in the placebo group had either bacteremia or clinical sepsis (43/132 vs 27/130). Other immediate, but transient, side effects observed in the dexamethasone group are: an increase in blood glucose and blood pressure, cardiac hypertrophy, hyperparathyroidism, and a transient delay in the rate of growth.

CONCLUSIONS

In preterm infants with severe respiratory distress syndrome requiring assisted ventilation shortly after birth, early postnatal dexamethasone therapy reduces the incidence of chronic lung disease, probably on the basis of decreasing the pulmonary inflammatory process during the early neonatal period. Infection or sepsis is the major side effect that may affect the immediate outcome. Other observable side effects are transient. In view of the significant side effects and the lack of overall improvement in outcome and mortality, and the lack of long term follow-up data, the routine use of early dexamethasone therapy is not yet recommended.

The adaptive immune response to major surgery in the neonate

The effect of major surgery on components of the adaptive immune response in babies has not previously been reported. In a prospective study, eight neonates undergoing uncomplicated surgery for repair of esophageal atresia were investigated. They were compared with ten age-matched normal babies not undergoing surgery. The parameters of the immune response investigated were: total leukocytes (WBC), lymphocytes and their subsets (T-helper, T-suppressor, natural killer [NK], B-lymphocytes), monocytes, immunoglobulins (Ig) G and M, the cytokines tumor necrosis factor-alpha (TNF-alpha) and interleukin 1-beta (Il-1beta), and C-reactive protein (CRP), an acute-phase protein. When compared to the normal controls, the operated group showed a fall in all types of WBC following surgery, but only the falls in B-lymphocytes and NK cells were significant on postoperative day 3 (P < 0.05). The suppression in WBC was temporary, and by day 7 the operated group had significantly higher numbers of total WBC and T-helper cells than the controls (P < 0.05), who were undergoing their physiological postpartum fall in WBC. Within the operated group, there was a significant fall in the numbers of total lymphocytes, T-suppressors, and B-lymphocytes compared to preoperative levels (P < 0.01). The ratio of T-helper/T-suppressor cells increased significantly following surgery. There was a vigorous immune response in terms of the humoral factors: CRP, TNF-alpha, and Il-1beta all rose significantly postoperatively (P < 0.02).

A prospective study on the relationship between intrapartum maternal group-B streptococcal concentration and signs of infection in neonates

OBJECTIVE

Our purpose was to examine the effects of intrapartum vaginal Group-B streptococcal (GBS) colonization on neonatal signs of infection.

STUDY DESIGN

We performed a quantitative GBS culture of vaginal specimens in 1,280 pregnancies within 24 hours before delivery and examined signs of neonatal infection within 48 hours after birth. Among them, 287 pregnant women had premature ruptures of membranes.

RESULTS

The rate of vaginal GBS colonization in groups with and without ruptured membranes was 22.0% and 11.3%, respectively. The incidence of neonates with signs of infection born to GBS-carrier women in each group was 28.6% and 8.8%, respectively. There were significant differences between the groups with regard to both the rate of colonization and the incidence of infection. Signs of neonatal infection increased in proportion to the maternal GBS concentration only in women with ruptured membranes.

CONCLUSION

This study suggests that there is an important association between maternal GBS concentration and mild neonatal infections after birth, especially in women with premature ruptures of membranes.

C-reactive protein as a diagnostic tool of sepsis in very immature babies

Three hundred and nine septic screens were performed on 123 consecutively admitted infants of < 30 weeks gestation. As part of the septic screen, serial quantitative measurements of C-reactive protein (CRP) were performed daily until discontinuation of antibiotic therapy. Complete blood counts were performed daily for the first 2 days of each septic episode. The babies had a mean birth weight of 1035.8 g s.d. 273.2 and a mean gestational age of 27 weeks s.d. 1.8. A CRP level of 10 mg/L or above was considered abnormal. Subsequently the receiver operator characteristic curve for CRP was constructed to demonstrate the ideal cut off value. Of the 309 septic screens, there were 51 instances of proven sepsis and 39 instances of deep culture negative sepsis. In the remaining 219, a diagnosis of proven or deep culture negative sepsis could not be made. On the first day of the septic episode CRP showed a sensitivity of 62.7%, specificity of 87.2% and negative predictive value of 92.2% for proven sepsis. There was a significant increase in the sensitivity (90.2%) and negative predictive value (97.7%) of CRP with a specificity of 80.6 when both day 1 and 2 estimations were combined. We conclude that when the CRP is elevated on day 1 and/or day 2, the diagnosis of sepsis is extremely likely and when the CRP is within normal limits on days 1 and 2 of the septic episode, neonatal sepsis can be confidently excluded and antibiotic therapy ceased.