The clinical application value of cytokines in treating infectious diseases

Profiles and predictive value of cytokines in children with human metapneumovirus pneumonia

BACKGROUND

Human metapneumovirus (HMPV) is an important cause of respiratory tract infections in young children. Early innate immune response to HMPV is focused on induction of antiviral interferons (IFNs) and other pro-inflammatory cytokines that are critical for the formation of adaptive immune responses. To evaluate the predictive value of Th1/Th2 cytokines which include IL-2, IL-4, IL-6, IL-10, INF-γ and TNF-α in pneumonia caused by HMPV.

METHODS

A retrospective study was performed among 59 pneumonia pediatric patients with HMPV infection and 33 healthy children as the control cohort, which was detected by the immunofluorescence assay, and the Th1/Th2 cytokines were measured by flow cytometry. 131 children infected with Influenza virus A (IVA) and 41 children infected with influenza virus B (IVB) were detected by RT-PCR assay in throat swabs.

RESULTS

When compared with the healthy children, children who were infected with HMPV pneumonia had a significantly lower level of IL-2 (p < 0.001) and higher levels of IL-4 (p < 0.001), IL-6 (p = 0.001), IL-10 (p < 0.001), and IFN-γ (p < 0.001). Compared with patients diagnosed with IVA or IVB infection, HMPV-positive patients had significantly higher levels of IL-4 (p < 0.001 and < 0.001), IFN-γ (p < 0.001 and < 0.001), and TNF-α (p < 0.001 and 0.016). Moreover, compared with IVA patients, HMPV-positive patients had a significantly lower level of IL-6 (p = 0.033). Finally, when comparing cytokine levels among the patients with HMPV pneumonia, IL-6 and TNF-α levels were found to be significantly higher in the severe group than the mild group (p = 0.027 and 0.049). The IL-6 and TNF-α were used to differentiate between mild symptoms and severe symptoms in children diagnosed with HMPV pneumonia with an AUC of 0.678 (95% CI 0.526-0.829) and 0.658 (95% CI 0.506-0.809), respectively.

CONCLUSION

Our study indicated that difference in cytokine trends depending on the virus species. The levels of IL-4, TNF-α and IFN-γ were significantly distinguished in children infected with HMPV versus IVA and IVB. IL-6 and TNF-α may be helpful in assessing the severity and prognosis of HMPV infection.

Localized cytokine responses to total knee arthroplasty and total knee revision complications

Background

The study of localized immune-related factors has proven beneficial for a variety of conditions, and one area of interest in the field of orthopaedics is the impact of implants and localized infections on immune response. Several cytokines have shown increased systemic concentrations (in serum/plasma) in response to implants and infection, but tissue-level cytokines have not been investigated as thoroughly.

Methods

This exploratory study investigated tissue-level cytokines in a cohort of patients (N = 17) in response to total knee arthroplasty and total knee revision to better understand the immune response to implants and localized infection (e.g., prosthetic joint infection). The overall goal of this study was to provide insight into the localized cytokine response of tissues and identify tissue-level markers specific to inflammation caused by implants vs. inflammation caused by infection. Tissues were collected across several anatomical locations and assayed with a panel of 20 human inflammatory cytokines to understand spatial differences in cytokine levels.

Results

In this study, six cytokines were elevated in implanted joints, as compared to native joints: IL-10, IL-12p70, IL-13, IL-17A, IL-4, and TNF-α (p < 0.05). Seven cytokines showed infection-dependent increases in localized tissues: IL-1α, IL-1β, IL-6, IL-8, MCP-1, MIP-1α, and MIP-1β (p < 0.05).

Conclusions

This study demonstrated that differences exist in tissue-level cytokines in response to presence of implant, and some cytokines were specifically elevated for infection; these responses may be informative of overall tissue health. These results highlight the utility of investigating localized cytokine concentrations to offer novel insights for total knee arthroplasty and total knee revision procedures, as well as their complications. Ultimately, this information could provide additional, quantitative measurements of tissue to aid clinical decision making and patient treatment options.

Biomarkers in pediatric sepsis: a review of recent literature

Sepsis remains the leading cause of death in infants and children worldwide. Prompt diagnosis and monitoring of infection is pivotal to guide therapy and optimize outcomes. No single biomarker has so far been identified to accurately diagnose sepsis, monitor response and predict severity. We aimed to assess existing evidence of available sepsis biomarkers, and their utility in pediatric population. C-reactive protein and procalcitonin remain the most extensively evaluated and used biomarkers. However, biomarkers related to endothelial damage, vasodilation, oxidative stress, cytokines/chemokines and cell bioproducts have also been identified, often with regard to the site of infection and etiologic pathogen; still, with controversial utility. A multi-biomarker model driven by genomic tools could establish a personalized approach in future disease management.

Stability of 12 T-helper cell-associated cytokines in human serum under different pre-analytical conditions

Cytokines are soluble and readily analyzed signaling molecules which reveal vital cues about the state of the immune system. As such, they serve in diagnosis and monitoring of immune-related disorders, where strictly controlled handling of the samples including storage and freeze/thawing procedures are required. In basic research and clinical trials, human serum samples can be left for long-term storage before processing. Storage space is commonly limited in scientific laboratories, which require storage of fewer but larger aliquots of patient serum samples. There are also practical limitations to the number of analytes to be processed at the same time. Further, new findings and technological progress might prompt analysis of hitherto unconsidered or undetectable molecules. Repeated freeze/thawing of serum samples is therefore a likely scenario, raising the question of the stability of the measured analytes under such conditions. To address this question, we subjected serum samples with spiked-in T-helper cell associated cytokines to several cycles of freeze/thawing under different conditions, including storage at -20 °C or -80 °C and thawing at 4 °C, 22 °C, and 37 °C, respectively. The concentration of TNF-α, IL-4, IL-17F, and IL-22 decreased after storage at room temperature for 4 h before freezing. Generally, storage at -20 °C resulted in reduced cytokine concentrations. This contrasts storage at -80 °C, which gave stable analyte concentrations; unaffected by repeated freeze/thaw cycles. The study presented here highlights the need for sentinel samples with known cytokine concentrations as internal control for the freeze/thaw process.

Clinical Significance of Interleukin-6 in the Diagnosis of Sepsis and Discriminating Sepsis Induced by Gram-negative Bacteria

BACKGROUND

To discuss the clinical significance of interleukin (IL)-6 in the differential diagnosis of sepsis and its capability of differentiating the sepsis induced by Gram-negative bacteria from that induced by Gram-positive bacteria.

METHODS

A total of 379 children with sepsis were involved in this study to form the case group, and their C-reactive protein (CRP), procalcitonin (PCT) and IL-6 levels before antibiotics and after recovery were checked. Receiver operating characteristic curve was applied to evaluate the significance of CRP, PCT and IL-6 in the differential diagnosis of sepsis and their capability of differentiating the sepsis induced by Gram-negative bacteria from that induced by Gram-positive bacteria.

RESULTS

When these 3 indicators were applied to the differential diagnosis of sepsis, the area under the curve (AUC) of IL-6, PCT and CRP was 0.881, 0.877 and 0.754, respectively. The combination of IL-6 and PCT presented highest diagnostic efficiency. CRP, PCT and IL-6 levels in children with sepsis induced by Gram-negative bacteria were significantly higher than those in children with sepsis induced by Gram-positive bacteria.

CONCLUSIONS

CRP, IL-6 and PCT are applicable to the differential diagnosis of sepsis and differentiating the sepsis induced by Gram-negative bacteria from Gram-positive bacteria. Appropriate combinations of these indicators are capable of increasing differential diagnosis efficiency. These indicators can be used as markers of antibiotics usage, but whether they can be used as markers to withdraw antibiotics is still needed to be observed.

Utility of Assessing Cytokine Levels for the Differential Diagnosis of Pneumonia in a Pediatric Population

OBJECTIVES

Although pneumonia is easily diagnosed, determining the causative agent is difficult due to low pathogen detection rates. We performed a prospective observational study to evaluate the utility of measuring inflammatory cytokine levels to discriminate between pneumonia caused by typical bacteria, respiratory syncytial virus, or Mycoplasma pneumoniae in a pediatric population.

DESIGN

Serum inflammatory cytokine levels at early stages of the disease were evaluated for pneumonia caused by the three different pathogenic microorganisms.

SETTING

The Children's Hospital of Zhejiang University School of Medicine, China.

PATIENTS

One hundred sixty-six patients with bacterial pneumonia, 182 with M. pneumonia, and 167 with respiratory syncytial virus pneumonia.

MEASUREMENTS AND MAIN RESULTS

The levels of interleukin-6 for pneumonia were significantly higher with typical bacteria than with either Mycoplasma pneumoniae or respiratory syncytial virus (p < 0.001). The area under the curve for serum concentrations of interleukin-6 was 0.997. A serum interleukin-6 level of greater than or equal to 93.0 pg/mL had 100.0% sensitivity and 99.14% specificity in discriminating bacterial pneumonia from respiratory syncytial virus pneumonia and Mycoplasma pneumoniae pneumonia. The interleukin-6 levels were higher in patients with Mycoplasma pneumoniae pneumonia than in those with respiratory syncytial virus pneumonia (p < 0.001). They also simultaneously had lower interleukin-10 levels than patients with respiratory syncytial virus pneumonia who had interleukin-10 levels comparable to those of patients with bacterial pneumonia, indicating a significant difference in the interleukin-6/interleukin-10 ratio between patients with Mycoplasma pneumoniae pneumonia and respiratory syncytial virus pneumonia (median interleukin-6/interleukin-10 ratio, 2.5 vs 0.5; p < 0.001). At an optimal cut-off value of 0.8, the interleukin-6/interleukin-10 ratio showed 90.3% sensitivity and 88.0% specificity.

CONCLUSIONS

These results suggest that interleukin-6 is a good biomarker for identifying bacterial pneumonia and that the interleukin-6/interleukin-10 ratio is an effective biomarker for discriminating Mycoplasma pneumoniae pneumonia from respiratory syncytial virus pneumonia.

Utility of cytokines to predict neonatal sepsis

BACKGROUND

Sepsis is an important cause of neonatal morbidity and mortality worldwide. Diagnosis and treatment of neonatal sepsis relies on clinical judgment and interpretation of nonspecific laboratory tests. In a prospective cohort, we measured inflammatory cytokines as a potential biomarker for neonatal sepsis.

METHODS

Serum inflammatory cytokine levels were evaluated in the early stage of neonatal sepsis and after antimicrobial treatment. Receiver operating characteristic curves assessed the diagnostic value of cytokines. We performed multiple logistic regression analysis to characterize the role of each cytokine independently for infants with culture proven sepsis.

RESULTS

C-reactive protein, interleukin (IL)-6, IL-10 and IL-6/IL-10 levels were significantly elevated in neonatal sepsis when compared with the control group and there were 1.4 (95% confidence interval (CI): 1.2-1.5), 4.9 (95% CI: 4.6-5.1), 5.1 (95% CI: 4.5-5.6), and 10.2 (95% CI: 9.2-11.1) fold greater odds, respectively, to predict neonatal sepsis when increased. After effective treatment, median IL-6 (pretreatment value: 263.0 pg/ml and post-treatment value: 7.4 pg/ml) and IL-6/IL-10 levels (pretreatment value: 16.6 and post-treatment value: 1.4) significantly decreased. The areas under the curve for IL-6, IL-10, IL-6/IL-10 and C-reactive protein for differential diagnosis were 0.98, 0.82, 0.90, and 0.88, respectively.

CONCLUSION

IL-6 and IL-6/IL-10 outperformed C-reactive protein to diagnose neonatal sepsis. Of the cytokines studied, IL-6 was the most sensitive, whereas IL-6/IL-10 was the most specific predictor of neonatal sepsis.

Epidemiology and Cytokine Levels among Children with Nosocomial Multidrug-Resistant Acinetobacter baumannii Complex in a Tertiary Hospital of Eastern China

BACKGROUND AND AIM

The present study was aimed at assessing the characteristics of children with nosocomial multidrug-resistant Acinetobacter baumannii complex (MDR ABC) in a tertiary hospital of eastern China. MDR ABC poses a serious threat to public health. However, information on nosocomial MDR ABC in children is lacking.

METHOD

This study retrospectively reviewed the cases in a tertiary hospital of eastern China between January 1, 2011, and December 31, 2014 (excluding outpatients).

RESULTS

A total of 377 non-duplicated nosocomial ABC isolates were collected from various samples including 200 (53.1%) MDR ABC isolates. Moreover, 158 of the 200 MDR ABC isolates were collected from intensive care units (ICUs; MDR constituent ratios, 62.5%), while 98 of the 200 MDR ABC isolates were collected from children older than 1 year (MDR constituent ratios, 62.8%). Multivariate logistic analysis revealed that being in the surgical intensive care unit (SICU), prolonged hospital stay, surgical intervention, and mechanical ventilation were independent risk factors for MDR acquisition among children with nosocomial ABC. The interleukin (IL)-6 level of children with nosocomial MDR ABC was significantly lower than that of the children with nosocomial non-MDR ABC.

CONCLUSION

Nosocomial MDR ABC infection is a serious concern in pediatric patients. Being in the SICU, prolonged hospital stay, surgical intervention, and mechanical ventilation increased the risk of nosocomial MDR ABC. IL-6 might be involved in developing nosocomial MDR ABC among children.

Clinical Value of Assessing Cytokine Levels for the Differential Diagnosis of Bacterial Meningitis in a Pediatric Population

We performed a prospective observational study to evaluate the utility of measuring inflammatory cytokine levels to discriminate bacterial meningitis from similar common pediatric diseases. Inflammatory cytokine levels and other cerebrospinal fluid (CSF) physicochemical indicators were evaluated in 140 patients who were diagnosed with bacterial meningitis via microbiological culture or PCR assay. The CSF concentrations of interleukin (IL)-6 and IL-10, CSF/blood IL-6 and IL-10 ratios, CSF white blood cell count, and CSF micro total protein were significantly elevated in bacterial meningitis patients compared with healthy children or patients with viral encephalitis, epilepsy, or febrile convulsions (P < 0.001). The area under the curve values for CSF concentrations of IL-6 and IL-10, CSF/blood IL-6 and IL-10 ratios, CSF white blood cell count, and CSF micro total protein to identify bacterial meningitis episodes by receiver-operating characteristic analysis were 0.988, 0.949, 0.995, 0.924, 0.945, and 0.928, respectively. The area under the curve for the combination of CSF IL-6 and CSF/blood IL-6 ratio was larger than that for either parameter alone, and the combination exhibited enhanced specificity and positive predictive value. After effective meningitis treatment, CSF IL-6 levels dropped significantly. These results suggest that CSF IL-6 and CSF/blood IL-6 ratio are good biomarkers in discriminating bacterial meningitis. Evaluating CSF IL-6 and CSF/blood IL-6 ratio in combination can improve diagnostic efficiency. Additionally, CSF IL-6 levels can be used to monitor the effects of bacterial meningitis treatment.

Th1/Th2 Cytokine Profile and Its Diagnostic Value in Mycoplasma pneumoniae Pneumonia

BACKGROUND

The levels of Th1/Th2 cytokine can alter in pathogenic infection in children with pneumonia.

OBJECTIVES

To evaluate Th1/Th2 cytokine profile and its diagnostic value in M. pneumoniae pneumonia in children.

PATIENTS AND METHODS

Children with M. pneumoniae mono-infection and 30 healthy children were tested with cytokines assay. We used real time PCR to detect M. pneumoniae in children with pneumonia.

RESULTS

M. pneumoniae test was positive in 2188 (16.62%) out of 13161 pneumonia children. Children aged 5 - 9 years had the highest rate and summer was a season with high rate of M. pneumoniae incidence in Zhejiang province. During the course of study, in 526 pneumonia children with M. pneumoniae mono-infection and 30 healthy children cytokines assay was performed. IL-2 level of M. pneumoniae pneumonia children was lower than that of healthy children (median levels, pg/mL: IL-2: 3.2 vs. 5.7, P = 0.00), while IL-4, IL-10 and IFN-γ were higher than in healthy children (median levels, pg/mL: IL-4: 3.2 vs. 1.5, P = 0.00; IL-10: 5.6 vs. 2.5, P = 0.001; IFN-γ: 20.4 vs. 4.8, P = 0.001).

CONCLUSIONS

IL-2 decreases and IL-4, IL-10 and IFN-γ increase in children with M. pneumoniae pneumonia, which has a promising prospect in diagnosis of this disease in clinical practice.

Host-pathogen interactions in Vibrio vulnificus: responses of monocytes and vascular endothelial cells to live bacteria

AIM

To demonstrate that Vibrio vulnificus, a sepsis-related aquatic pathogen, can provoke a strong pro-inflammatory reaction in blood-associated target cells.

MATERIALS & METHODS

We selected two strains of the two main phylogenetic lineages, two human cell lines, monocytes and vascular endothelial cells and designed an in vitro infection model simulating early septicemia.

RESULTS

Both strains caused a strong cell-specific pro-inflammatory response and produced a high degree of cell damage that ended with death by lysis (endothelial cells) or apoptosis/lysis (monocytes). The interaction with endothelial cells was stronger than expected and significantly different for both lineages.

CONCLUSION

The early interaction with endothelial cells could have a direct role in sepsis and could explain, at least partially, the differences in pathogenicity between both lineages.

24h Urinary Protein Levels and Urine Protein/Creatinine Ratios Could Probably Forecast the Pathological Classification of HSPN

This study aimed to assess the relevance of laboratory tests in Henoch-Schönlein purpura nephritis (HSPN) classification, and determine accurate classification factors. This prospective study included 694 HSPN patients who underwent ultrasound-guided percutaneous renal biopsy (PRB). Renal specimens were scored according to International Study of Kidney Disease in Children (ISKDC) classification. Meanwhile, blood samples were immediately collected for laboratory examination. The associations between laboratory parameters and HSPN classification were assessed. Significant differences in levels of serum Th1/Th2 cytokines, immunoglobulins, T-lymphocyte subsets, complement, and coagulation markers were obtained between HSPN patients and healthy children. Interestingly, 24h urinary protein (24h-UPRO) levels and urine protein/urine creatinine ratios could determine HPSN grade IIb, IIIa, and IIIb incidences, with areas under ROC curve of 0.767 and 0.731, respectively. At 24h-UPRO >580.35mg/L, prediction sensitivity and specificity were 75.2% and 70.0%, respectively. These values became 53.0% and 82.3%, respectively, with 24h-UPRO exceeding 1006.25mg/L. At urine protein/urine creatinine > 0.97, prediction sensitivity and specificity were 65.5% and 67.2%, respectively, values that became 57.4% and 80.0%, respectively, at ratios exceeding 1.2. Cell and humoral immunity, coagulation and fibrinolytic systems are all involved in the pathogenesis of HSPN, and type I hypersensitivity may be the disease trigger of HSPN. 24h-UPRO levels and urine protein/creatinine ratios could probably forecast the pathological classification of HSPN.

Relationship between immune parameters and organ involvement in children with Henoch-Schonlein purpura

Henoch-Schonlein purpura (HSP) is the most common type of connective tissue diseases which increasingly occurs in children in recent years and its pathogenesis remains unclear. In order to explore the immune parameters and underlying pathogenesis mechanism of children with HSP, the study involved 1232 patients with HSP having different clinical symptoms and their laboratory indicators were evaluated. Th1/Th2 imbalance and overactivity of Th2 cells can cause increase in the synthesis and release of immunoglobulins in children with HSP. The number of red blood cells and white blood cells in urine was directly proportional to the level of IgA and inversely proportional to the level of serum complements (C3 and C4). Activation of these complements caused by immunoglobulin in patients with HSP plays an important role in renal injury. The urinary protein content in children with HSP along with proteinuria was positively correlated with IgE level, and IgE mediated type 1 hypersensitivity can cause increase in capillary permeability and weakened the charge barrier; hence, it could be considered as one of the causes of proteinuria in HSP. Additionally, the NK cells percentage was reduced and impaired immune function of NK cells were related to the immune injury of the digestive tract and kidney.

Epidemiological characteristics and immune status of children with Respiratory Syncytial Virus

Respiratory Syncytial Virus (RSV) infections are the dominant cause of pneumonia in children. In order to determine the epidemiological characteristics and immune status of children with Respiratory Syncytial Virus, a prospective study was performed among patients with RSV infection. Comparisons between RSV pneumonia group and normal control group, RSV pneumonia group had lower IL-2 (median levels, pg/ml: 3.8 vs. 5.1, P < 0.01), and higher IL-4 (median levels, pg/ml: 3.2 vs. 2.4, P < 0.01), IL-10 (median levels, pg/ml: 12.2 vs. 2.3, P < 0.01), and IFN-γ (median levels, pg/ml: 13.4 vs. 4.6, P < 0.01). The level of IgE among pneumonia patients caused by RSV increased sharply (median levels, mg/L: 48.1 vs. 8.8, P < 0.01). Another amazing finding is that after birth, the degree of IgE of the children infected by RSV increases gradually with age. This effect is at its peak in 0.6 years old. The IgE and eosinophil levels were higher when patients suffered from RSV pneumonia with wheeze (IgE median levels, IU/ml: with wheeze: 72.74 vs. without wheeze: 11.5, P < 0.05; eosinophil median levels, ×10(9) /l: with wheeze: 0.21 vs. without wheeze: 0.05, P < 0.05). The main morbidity crowd is the children under the age of 1 year old. The downregulation of IL2 and the upregulation of IL-4, IL-10, IFN-γ, and IgE happen after RSV infection.