Patients hospitalized with severe influenza have more active and prolonged viral replication. Weakened host defenses slow viral clearance, whereas antivirals started within the first 4 days of illness enhance viral clearance.

Our findings suggested "early" corticosteroid treatment was associated with a higher subsequent plasma viral load.

These 6MWD standards will provide useful references for the care of pediatric patients.

This study aims to evaluate the diagnostic utilities of four leukocyte surface antigens-two lymphocyte antigens (CD25 and CD45RO) and two neutrophil antigens (CD11b and CD64)-for identification of late-onset nosocomial bacterial infection in preterm, very low birthweight infants, and to define the optimal cutoff value for each marker so that it may act as a reference with which future studies can be compared. Very low birthweight infants in whom infection was suspected when they were Ͼ72 h of age were eligible for the study. A full sepsis screen was performed in each episode. IL-6, C-reactive protein, and leukocyte surface antigens (CD25, CD45RO, CD11b, and CD64) were measured at 0 (at the time of sepsis evaluation), 24, and 48 h by standard biochemical methods and quantitative flow cytometric analysis. The diagnostic utilities including sensitivity, specificity, and positive and negative predictive values of each marker and combination of markers for predicting late-onset neonatal infection were determined. One hundred twenty-seven episodes of suspected clinical sepsis were investigated in 80 infants. Thirty-seven episodes were proven infection. The calculated optimal cutoff values for CD25, CD45RO, CD11b, and CD64 were 3,100, 2,900, 10,450, and 4,000 phycoerythrinmolecules bound per cell, respectively. An interim analysis of data after 68 episodes suggested that CD25 and CD45RO were poor predictors of neonatal infection with sensitivity or specificity Ͻ75% during a single measurement. Thus, these two markers were excluded from further investigation. In the final analysis, CD64 has the highest sensitivity (95-97%) and negative predictive value (97-99%) at 0 and 24 h after the onset. The addition of IL-6 or C-reactive protein (0 h) to CD64 (24 h) further enhanced the sensitivity and negative predictive value to 100%, and has the specificity and positive predictive value exceeding 88% and 80%, respectively. Neutrophil CD64 expression is a very sensitive marker for diagnosing late-onset nosocomial infection in very low birthweight infants. If further validated, the use of CD64 as an infection marker should allow early discontinuation of antibiotic treatment at 24 h without waiting for the definitive microbiologic culture results. The quantitative flow cytometric analysis applied in this study could be developed into a routine clinical test with high comparability and reproducibility across different laboratories. Vol. 51, No. 3, 2002 Copyright © 2002 Printed in U.S.A. ABSTRACT296

Objective: A prospective study to investigate the pattern of proinflammatory and anti-inflammatory cytokine responses in preterm infants with systemic infection. Methods: Very low birthweight infants in whom infection was suspected when they were > 72 hours of age were eligible. A full sepsis screen was performed in each episode. Key cytokines of both proinflammatory and anti-inflammatory pathways, including interleukin (IL) 2, IL4, IL5, IL6, IL10, interferon (IFN) γ, and tumour necrosis factor (TNF) α, were measured at 0 (at the time of sepsis evaluation), 24, and 48 hours by flow cytometric analysis or immunoassay. Results: Thirty seven of the 127 episodes of suspected clinical sepsis were proven infection or necrotising enterocolitis. Both proinflammatory (IL2, IL6, IFNγ, TNFα) and anti-inflammatory (IL4, IL10) cytokines were significantly increased in infected infants compared with non-infected infants. Significant correlations were observed between IL6 and TNFα or IL10 as well as IL10 and IFNγ in infected infants. In the subgroup analysis, plasma IL6, IL10, and TNFα concentrations, and IL10/TNFα and IL6/IL10 ratios were significantly elevated in patients with disseminated intravascular coagulation compared with infected infants without. The IL10/TNFα ratios had decreased significantly 48 hours after the onset, whereas the IL6/IL10 ratio showed only a non-significant decreasing trend. Further, the IL6/IL10 ratio in the deceased infant was disproportionally increased at presentation and continued to increase despite treatment. Conclusion:The results indicate that the counter-regulatory mechanism between the proinflammatory and anti-inflammatory cytokine pathways is probably operational in preterm infants of early gestation. High plasma IL6, IL10, and TNFα concentrations, and IL10/TNFα and IL6/IL10 ratios signify severe infection, but transiently elevated plasma IL10 concentration or IL10/TNFα ratio does not necessarily indicate a poor prognosis.

This prospective study aimed to evaluate the diagnostic utilities of neutrophil CD64 expression for the identification of early-onset clinical infection and pneumonia in term infants and to define the optimal cutoff value so that it may act as a reference with which future studies can be compared. Term newborns in whom infection was suspected when they were Ͻ72 h of age were recruited into the study. C-reactive protein (CRP) and expression of CD64 on neutrophils were measured at 0 h (at the time of sepsis evaluation) and 24 h. The sensitivity, specificity, positive predictive value, and negative predictive value (NPV) of CRP, CD64, and the combination of these two markers for predicting neonatal sepsis were determined. A total of 338 infants with suspected clinical sepsis were investigated, 115 of whom were found to be clinically infected. CRP and CD64 in infected infants were both significantly elevated at 0 and 24 h compared with noninfected infants (p Ͻ 0.001). The calculated optimal cutoff value for CD64 was 6136 antibody-phycoerythrin molecules bound/cell. CD64 has a very high sensitivity (96%) and NPV (97%) at 24 h. The addition of CRP only marginally enhanced the sensitivity and NPV (97 and 98%, respectively). In conclusion, neutrophil CD64 is a very sensitive diagnostic marker for the identification of early-onset clinical infection and pneumonia in term newborns. The results strongly suggest that measurement of neutrophil CD64 may allow neonatal clinicians to discontinue antibiotic treatment at 24 h in infants who are clinically stable and whose CD64 expressions are below the optimal cutoff level. Early-onset (Ͻ72 h of age) neonatal infection is associated with a high morbidity and mortality (1). Immature immunologic defenses in newborn infants, including low circulating levels of immunoglobulins, decrease in absolute number of T lymphocytes and neutrophils, and functionally impaired cytotoxic activity in leukocytes (2-4), are important risk factors that predispose these infants to life-threatening sepsis. Early clinical signs and symptoms of neonatal infection and pneumonia are often inconspicuous and can easily be confused with other noninfective causes, such as transient tachypnea of the newborns, meconium aspiration syndrome, congenital heart diseases, and hypoxic-ischemic encephalopathy (5). Thus, there is always a possibility that the attending neonatologists may overlook or miss subtle cases of early infection. In view of the potentially serious outcome associated with delayed treatment and the difficulty in distinguishing infected from noninfected cases, it has become common practice to prescribe broad-spectrum antibiotics for suspected infection that presents with nonspecific clinical features and maternal risk factors (5-7). Furthermore, as negative microbiologic culture results do not always suggest the absence of bacterial sepsis, continuation of antimicrobial therapy for presumptive infection frequently leads to unnecessary and prolonged treatment and increases in duration of hospitalizatio...

Severe SARS is associated with a more robust IgG response.

No abstract