Discriminatory plasma biomarkers predict specific clinical phenotypes of necrotizing soft-tissue infections.

BACKGROUNDNecrotizing soft-tissue infections (NSTIs) are rapidly progressing infections frequently complicated by septic shock and associated with high mortality. Early diagnosis is critical for patient outcome, but challenging due to vague initial symptoms. Here, we identified predictive biomarkers for NSTI clinical phenotypes and outcomes using a prospective multicenter NSTI patient cohort.METHODSLuminex multiplex assays were used to assess 36 soluble factors in plasma from NSTI patients with positive microbiological cultures (n = 251 and n = 60 in the discovery and validation cohorts, respectively). Control groups for comparative analyses included surgical controls (n = 20), non-NSTI controls (i.e., suspected NSTI with no necrosis detected upon exploratory surgery, n = 20), and sepsis patients (n = 24).RESULTSThrombomodulin was identified as a unique biomarker for detection of NSTI (AUC, 0.95). A distinct profile discriminating mono- (type II) versus polymicrobial (type I) NSTI types was identified based on differential expression of IL-2, IL-10, IL-22, CXCL10, Fas-ligand, and MMP9 (AUC >0.7). While each NSTI type displayed a distinct array of biomarkers predicting septic shock, granulocyte CSF (G-CSF), S100A8, and IL-6 were shared by both types (AUC >0.78). Finally, differential connectivity analysis revealed distinctive networks associated with specific clinical phenotypes.CONCLUSIONSThis study identifies predictive biomarkers for NSTI clinical phenotypes of potential value for diagnostic, prognostic, and therapeutic approaches in NSTIs.TRIAL REGISTRATIONClinicalTrials.gov NCT01790698.FUNDINGCenter for Innovative Medicine (CIMED); Region Stockholm; Swedish Research Council; European Union; Vinnova; Innovation Fund Denmark; Research Council of Norway; Netherlands Organisation for Health Research and Development; DLR Federal Ministry of Education and Research; and Swedish Children's Cancer Foundation.

Hyperbaric oxygen treatment is associated with a decrease in cytokine levels in patients with necrotizing soft-tissue infection.

BACKGROUND: The pathophysiological understanding of the inflammatory response in necrotizing soft-tissue infection (NSTI) and its impact on clinical progression and outcomes are not resolved. Hyperbaric oxygen (HBO2 ) treatment serves as an adjunctive treatment; however, its immunomodulatory effects in the treatment of NSTI remains unknown. Accordingly, we evaluated fluctuations in inflammatory markers during courses of HBO2 treatment and assessed the overall inflammatory response during the first 3 days after admission. METHODS: In 242 patients with NSTI, we measured plasma TNF-α, IL-1ß, IL-6, IL-10, and granulocyte colony-stimulating factor (G-CSF) upon admission and daily for three days, and before/after HBO2 in the 209 patients recieving HBO2 . We assessed the severity of disease by Simplified Acute Physiology Score (SAPS) II, SOFA score, and blood lactate. RESULTS: In paired analyses, HBO2 treatment was associated with a decrease in IL-6 in patients with Group A-Streptococcus NSTI (first HBO2 treatment, median difference -29.5 pg/ml; second HBO2 treatment, median difference -7.6 pg/ml), and overall a decrease in G-CSF (first HBO2 treatment, median difference -22.5 pg/ml; 2- HBO2 treatment, median difference -20.4 pg/ml). Patients presenting with shock had significantly higher baseline cytokines values compared to non-shock patients (TNF-α: 51.9 vs. 23.6, IL-1ß: 1.39 vs 0.61, IL-6: 542.9 vs. 57.5, IL-10: 21.7 vs. 3.3 and G-CSF: 246.3 vs. 11.8 pg/ml; all p < 0.001). Longitudinal analyses demonstrated higher concentrations in septic shock patients and those receiving renal-replacement therapy. All cytokines were significantly correlated to SAPS II, SOFA score, and blood lactate. In adjusted analysis, high baseline G-CSF was associated with 30-day mortality (OR 2.83, 95% CI: 1.01-8.00, p = 0.047). CONCLUSION: In patients with NSTI, HBO2 treatment may induce immunomodulatory effects by decreasing plasma G-CSF and IL-6. High levels of inflammatory markers were associated with disease severity, whereas high baseline G-CSF was associated with increased 30-day mortality.

The use of extrapolation based on modeling and simulation to support high-dose regimens of ceftaroline fosamil in pediatric patients with complicated skin and soft-tissue infections.

A model-informed drug development approach was used to select ceftaroline fosamil high-dose regimens for pediatric patients with complicated skin and soft-tissue infections caused by Staphylococcus aureus with a ceftaroline minimum inhibitory concentration (MIC) of 2 or 4 mg/L. Steady-state ceftaroline concentrations were simulated using a population pharmacokinetics (PK) model for ceftaroline fosamil and ceftaroline including data from 304 pediatric subjects and 944 adults. Probability of target attainment (PTA) for various simulated pediatric high-dose regimens and renal function categories were calculated based on patients achieving 35% fT>MIC (S. aureus PK/pharmacodynamic target for 2-log10 bacterial killing). For extrapolation of efficacy, simulated exposures and PTA were compared to adults with normal renal function receiving high-dose ceftaroline fosamil (600 mg 2-h infusions every 8 h). For safety, predicted ceftaroline exposures were compared with observed pediatric and adult data. Predicted ceftaroline exposures for the approved pediatric high-dose regimens (12, 10, or 8 mg/kg by 2-h infusions every 8 h for patients aged >2 to <18 years with normal/mild, moderate, or severe renal impairment, respectively; 10 mg/kg by 2-h infusions every 8 h for patients aged ≥2 months to <2 years with normal renal function/mild impairment) were well matched to adults with normal renal function. Median predicted maximum concentration at steady state (Cmax,ss ) and area under the plasma concentration-time curve over 24 h at steady state pediatric to adult ratios were 0.907-1.33 and 0.940-1.41, respectively. PTAs (>99% and ≥81% for MICs of 2 and 4 mg/L, respectively) matched or exceeded the adult predictions. Simulated Cmax,ss values were below the maximum observed data in other indications, including a high-dose pediatric pneumonia trial, which reported no adverse events related to high exposure.

Evaluation of the Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC) score for detecting necrotizing soft tissue infections in patients with diabetes and lower extremity infection.

AIMS: The aim of this pilot study was to assess the Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC), a scoring system for Necrotizing Soft Tissue Infections, to diagnose Necrotizing Soft Tissue Infections of the lower extremity in patients with diabetes. METHODS: Sixty-nine patients with lower extremity infections were prospectively enrolled. The Laboratory Risk Indicator for Necrotizing Fasciitis was calculated and logistic regression was performed for each laboratory value. RESULTS: The Laboratory Risk Indicator for Necrotizing Fasciitis was associated with Necrotizing Soft Tissue Infection diagnosis in patients with diabetes (p = 0.01). Sensitivity, specificity, positive predictive value, and negative predictive value were 100%, 69%, 16.6%, and 100% respectively. Elevated C-reactive protein (OR 1.01, p = 0.02, 95% CI [1.002-1.23]) and white blood cell count (OR 1.34, p < 0.01, 95% CI [1.1-1.7]) were associated with Necrotizing Soft Tissue Infection. CONCLUSIONS: The Laboratory Risk Indicator for Necrotizing Fasciitis was useful as a negative predictor of Necrotizing Soft Tissue Infection while C- reactive protein and white blood cell count may have value as individual predictors. We recommend high clinical suspicion of Necrotizing Soft Tissue Infections in diabetics as laboratory evaluation may be non-specific.

The clinical characteristic and outcome of skin and soft tissue infection in immunosuppressive patients with nephrotic syndrome.

OBJECTIVE: Skin and soft tissue infection (SSTI) is the most common of infectious diseases with high morbidity and mortality. However, the clinical characteristics of SSTI in patients with nephrotic syndrome (NS), especially in those patients who received immunosuppressive therapy, are still lacking. The present study was conducted to investigate the clinical characteristics and outcomes of SSTI in patients with NS. METHODS: A retrospective study was carried out among the patients diagnosed with NS and SSTI, who have priorly received or currently have been receiving immunosuppressive therapy between April 2011 and January 2019; the clinical profile included patient's baseline characteristics, clinical presentation, microbiological findings, treatment, and prognosis. RESULTS: A total of 70 patients were analyzed. Results showed that more than half of the patients were under 35 years old, and moderate infection was the most common type of SSTI. Leg and cellulitis were the most common site of lesion and the typical clinical manifestation of SSTI, respectively. Patients in the severe infection group have a higher level of procalcitonin (PCT) and C-reactive protein (CRP), while a lower level of albumin, CD4+ T and CD8+ T cell count. Moreover, the gram-negative bacteria were the primary pathogens of SSTI in patients with NS, and Klebsiella pneumoniae were the most frequent strains isolated from those patients. Besides, patients in the mild and moderate infection groups experienced a better outcome. CONCLUSIONS: Patients with NS and SSTI usually showed a satisfying outcome with proper anti-infection treatment, but severe SSTI can be life-threatening.

Variation in Proportion of Blood Cultures Obtained for Children With Skin and Soft Tissue Infections.

OBJECTIVES: To identify variation in the proportion of blood cultures obtained for pediatric skin and soft tissue infections (SSTIs) among children's hospitals. METHODS: We conducted a retrospective cohort study using the Pediatric Health Information System database, which we queried for emergency department (ED)-only and hospital encounters between 2012 and 2017 for children aged 2 months to 18 years with diagnosis codes for SSTI. The primary outcome was proportion of SSTI encounters during which blood cultures were obtained. Encounters with and without blood cultures were compared for length of stay, costs, and 30-day ED revisit and readmission rates, adjusted for patient factors and hospital clustering. We also identified encounters with bacteremia using billing codes for septicemia and bacteremia. RESULTS: We identified 239 954 ED-only and 49 291 hospital SSTI encounters among 38 hospitals. Median proportions of ED-only and hospital encounters with blood cultures were 3.2% (range: 1%- 11%) and 51.6% (range: 25%-81%), respectively. Adjusted ED-only encounters with versus without blood culture had higher costs ($1266 vs $460, P < .001), higher ED revisit rates (3.6% vs 2.9%, P < .001), and higher admission rates (2.0% vs 0.9%, P < .001). Hospital encounters with blood culture had longer length of stay (2.3 vs 2.0 days, P < .001), higher costs ($5254 vs $4425, P < .001), and higher readmission rates (0.8% vs 0.7%, P = .027). The overall proportion of encounters with bacteremia was 0.6% for ED-only encounters and 1.0% for hospital encounters. CONCLUSIONS: Despite multiple studies in which low clinical value was demonstrated and current Infectious Diseases Society of America guidelines arguing against the practice, blood cultures were obtained frequently for children hospitalized with SSTIs, with substantial variation across institutions. Few bacteremic encounters were identified.

Complement Activation Is Associated With Mortality in Patients With Necrotizing Soft-Tissue Infections-A Prospective Observational Study.

Aim: We assessed whether different complement factors and complement activation products were associated with poor outcome in patients with necrotizing soft-tissue infection (NSTI). Methods: We conducted a prospective, observational study in an intensive care unit where treatment of NSTI is centralized at a national level. In 135 NSTI patients and 65 control patients, admission levels of MASP-1, MASP-2, MASP-3, C4, C3, complement activation products C4c, C3bc, and terminal complement complex (TCC) were assessed. Results: The 90-day mortality was 23%. In a Cox regression model adjusted for sex, and SAPS II, a higher than median MASP-1 (HR 0.378, CI 95% [0.164-0.872], p = 0.0226) and C4 (HR 0.162, 95% CI [0.060-0.438], p = 0.0003), C4c/C4 ratio (HR 2.290 95% CI [1.078-4.867], p = 0.0312), C3bc (HR 2.664 95% CI [1.195-5.938], p = 0.0166), and C3bc/C3 ratio (HR 4.041 95% CI [1.673-9.758], p = 0.0019) were associated with 90-day mortality, while MASP-2, C4c, C3, and TCC were not. C4 had the highest ROC-AUC (0.748, [95% CI 0.649-0.847]), which was comparable to the AUC for SOFA score (0.753, [95% CI 0.649-0.857]), and SAPS II (0.862 [95% CI 0.795-0.929]). Conclusion: In adjusted analyses, high admission levels of the C4c/C4 ratio, C3bc, and the C3bc/C3 ratio were significantly associated with a higher risk of death after 90 days while high admission levels of MASP-1 and C4 were associated with lower risk. In this cohort, these variables are better predictors of mortality in NSTI than C-reactive protein and Procalcitonin. C4's ability to predict mortality was comparable to the well-established scoring systems SAPS score II and SOFA on day 1.

Prospective Validation of the Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC) Score for Necrotizing Fasciitis of the Extremities.

OBJECTIVES: The Laboratory Risk Indicator for Necrotizing Fasciitis score was developed as a clinical decision tool for distinguishing necrotizing fasciitis from other soft tissue infections. We prospectively evaluated the performance of the Laboratory Risk Indicator for Necrotizing Fasciitis score for the diagnosis of patients with necrotizing fasciitis in the extremities. METHODS: We conducted a prospective and observational cohort study of emergency department patients with necrotizing fasciitis or severe cellulitis in the extremities between April 2015 and December 2016. The Laboratory Risk Indicator for Necrotizing Fasciitis score was calculated for every enrolled patient. The sensitivity, specificity, positive predictive value, and negative predictive value of cut-off scores of 6 and 8 were evaluated. The accuracy of the Laboratory Risk Indicator for Necrotizing Fasciitis score was expressed as the area under the receiver operating characteristic curve. RESULTS: A total of 106 patients with necrotizing fasciitis and 825 patients with cellulitis were included. With an Laboratory Risk Indicator for Necrotizing Fasciitis cut-off score ≥6, the sensitivity was 43% (95% confidence interval 34% to 53%), specificity was 83% (95% confidence interval 80% to 86%), positive predictive value was 25% (95% confidence interval 20% to 30%), and negative predictive value was 92% (95% confidence interval 91% to 93%); with an Laboratory Risk Indicator for Necrotizing Fasciitis cut-off score ≥8, the sensitivity was 27% (95% confidence interval 19% to 37%), specificity was 93% (95% confidence interval 91% to 94%), positive predictive value was 33% (95% confidence interval 25% to 42%), and negative predictive value was 91% (95% confidence interval 90% to 92%). The area under the receiver operating characteristic curve for accuracy of the Laboratory Risk Indicator for Necrotizing Fasciitis score was 0.696 (95% CI 0.640 to 0.751). CONCLUSION: The Laboratory Risk Indicator for Necrotizing Fasciitis score may not be an accurate tool for necrotizing fasciitis risk stratification and differentiation between severe cellulitis and necrotizing fasciitis in the emergency department setting based on our study.

Necrotizing Soft Tissue Infections: A Focused Review of Pathophysiology, Diagnosis, Operative Management, Antimicrobial Therapy, and Pediatrics.

Background: Necrotizing fasciitis is a major health problem throughout the world. The purpose of this review is to assist providers with the care of these patients through a better understanding of the pathophysiology and management options. Methods: This is a collaborative review of the literature between members of the Surgical Infection Society of North America and World Society of Emergency Surgery. Results: Necrotizing fasciitis continues to be difficult to manage with the mainstay being early diagnosis and surgical intervention. Recognition of at-risk populations assists with the initiation of treatment, thereby impacting outcomes. Conclusions: Although there are some additional treatment strategies available, surgical debridement and antimicrobial therapy are central to the successful eradication of the disease process.

The predictive value of procalcitonin for early detection of infection in elderly type 2 diabetes mellitus.

OBJECTIVE: Aimed to investigate the predictive value of procalcitonin (PCT) in early detection of infections in elderly patients with type 2 diabetes, and to discover the optimum cut-off points of PCT. METHODS: A retrospective study was conducted with type 2 diabetic patients (≥65 years) with lung infection (LI), urinary tract infection (UTI) or skin and soft tissue infection (SSTI). The receiver operating characteristic (ROC) curves of the 3 markers (PCT, WBC count, and CRP) were constructed and compared to assess their accuracies in diagnosing. RESULTS: Among the three different groups with LI, UTI or SSTI, the area under the ROC curve (AUC) of PCT was 0.98 (95% confidence interval (CI): 0.96-0.99, p < 0.05) for the LI group, 0.98 (95% CI: 0.96-0.99, p < 0.05) for the UTI group, and 0.97 (95% CI: 0.94-1.00, p < 0.05) for the SSTI group. The optimum cut-off point of PCT level was 0.73 ng/mL (Sn 89.7%, Sp 97.7%) for the LI group, 1.48 ng/mL (Sn 88.9%, Sp 100%) for the UTI group, and 0.73 ng/mL (Sn 85.7%, Sp 97.7%) for the SSTI group. CONCLUSION: PCT demonstrated the strongest correlation with each of the infection types, indicating significant diagnostic value. Optimum cut-off points of PCT levels in elderly diabetes were higher.

Accurate and quick predictor of necrotizing soft tissue infection: Usefulness of the LRINEC score and NSTI assessment score.

OBJECTIVE: The Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC) score is a diagnostic tool for necrotizing soft tissue infection (NSTI), which is validated and is considered to have high diagnostic value. However, some experts criticize LRINEC score for consisting of laboratory test results only. METHODS: In this single-center retrospective study, we created a new scoring system (NSTI assessment score; NAS), which also incorporated vital signs as another diagnostic tool for NSTI using cases from our hospital and also evaluated diagnostic accuracy of LRINEC score. We identified NSTI predictors by comparing 24 NSTI patients and 80 non NSTI patients using uni- and multivariate logistic regression analysis, and created NAS based on odds ratio of variables which are statistically significant in the multivariate model. RESULTS: We identified mean arterial pressure, C-reactive protein, hemoglobin, serum creatinine, and glucose as a predictor for NSTI. The maximum value of NAS was 11 points with the cut-off value of 6. Sensitivity, specificity, positive predictive value, and negative predictive value of the NAS for diagnosis of NSTI were 87.5%, 91.3%, 75.0%, and 96.1%, respectively. Area under the receiver operating characteristic curve was 0.926 (0.851-1.00) for the NAS and 0.903 (0.833-0.973) for the LRINEC score, and they were not statistically different (p = 0.167). CONCLUSION: The NAS has high diagnostic accuracy in predicting NSTI, and is comparable with the LRINEC score. The NAS needs to be validated in other cohorts in the future.

Factors associated with blood culture positivity in patients with complicated skin and skin structure infection-a population-based study.

Skin and skin structure infection (SSSI) is classified as complicated (cSSSI) if it involves deep subcutaneous tissue or requires surgery. Factors associated with blood culture sampling and bacteremia have not been established in patients with cSSSI. Moreover, the benefit of information acquired from positive blood culture is unknown. The aim of this study was to address these important issues. In this retrospective population-based study from two Nordic cities, a total of 460 patients with cSSSI were included. Blood cultures were drawn from 258 (56.1%) patients and they were positive in 61 (23.6%) of them. Factors found to be associated with more blood culture sampling in multivariate analysis were diabetes, duration of symptoms shorter than 2 days and higher C-reactive protein (CRP) level. Whereas factors associated with less frequent blood culture sampling were peripheral vascular disease and a surgical wound infection. In patients from whom blood cultures were taken, alcohol abuse was the only factor associated with culture positivity, as CRP level was not. Patients with a positive blood culture had antibiotic streamlining more often than non-bacteremic patients. A high rate of blood culture positivity in patients with cSSSI was observed. Factors related to more frequent blood culture sampling were different from those associated with a positive culture.

Retrospective Identification of a Broad IgG Repertoire Differentiating Patients With S. aureus Skin and Soft Tissue Infections From Controls.

Background: Although the relevance of humoral immunity for protection against S. aureus skin and soft tissue infections (SSTIs) has been suggested by several animal and human studies, the question of which human antibodies may be protective has so far impeded the development of a safe and effective vaccine. Because most adults have developed certain anti-S. aureus antibodies due to S. aureus colonization or infection, we hypothesized that the titers of antibodies to S. aureus in uninfected controls would differ from those in infected patients and would also differ in infected patients from the time of acute infection to a 40-day convalescent serum. Methods: To test these hypotheses, we measured human antibody levels against a panel of 134 unique antigens comprising the S. aureus surfome and secretome in subjects with active culture-confirmed S. aureus SSTIs (cases) and in controls with no infection, using a novel S. aureus protein microarray. Results: Most S. aureus SSTI patients (n = 60) and controls (n = 142) had antibodies to many of the tested S. aureus antigens. Univariate analysis showed statistically weak differences in the IgG levels to some antigens in the SSTI patient (case) sera compared with controls. Antibody levels to most tested antigens did not increase comparing acute with 40-day serum. Multiple logistic regression identified a rich subset of antigens that, by their antibody levels, together correctly differentiated all cases from all controls. Conclusions: Antibodies directed against S. aureus antigens were present both in patients with S. aureus SSTIs and in uninfected control patients. We found that SSTI patients and controls could be distinguished only based on differences in antibody levels to many staphylococcal surface and secreted antigens. Our results demonstrate that in the studied population, the levels of anti-S. aureus antibodies appear largely fixed, suggesting that there may be some level of unresponsiveness to natural infection.

Protein SIC Secreted from Streptococcus pyogenes Forms Complexes with Extracellular Histones That Boost Cytokine Production.

Innate immunity relies on an effective recognition of the pathogenic microorganism as well as on endogenous danger signals. While bacteria in concert with their secreted virulence factors can cause a number of inflammatory reactions, danger signals released at the site of infection may in addition determine the amplitude of such responses and influence the outcome of the disease. Here, we report that protein SIC, Streptococcal Inhibitor of Complement, an abundant secreted protein from Streptococcus pyogenes, binds to extracellular histones, a group of danger signals released during necrotizing tissue damage. This interaction leads to the formation of large aggregates in vitro. Extracellular histones and SIC are abundantly expressed and seen colocalized in biopsies from patients with necrotizing soft-tissue infections caused by S. pyogenes. In addition, binding of SIC to histones neutralized their antimicrobial activity. Likewise, the ability of histones to induce hemolysis was inhibited in the presence of SIC. However, when added to whole blood, SIC was not able to block the pro-inflammatory effect of histones. Instead SIC boosted the histone-triggered release of a broad range of cytokines and chemokines, including IL-6, TNF-α, IL-8, IL-1ß, IL-1ra, G-CSF, and IFN-γ. These results demonstrate that the interaction between SIC and histones has multiple effects on the host response to S. pyogenes infection.

Associations of Plasma Nitrite, L-Arginine and Asymmetric Dimethylarginine With Morbidity and Mortality in Patients With Necrotizing Soft Tissue Infections.

BACKGROUND: The nitric oxide system could play an important role in the pathophysiology related to necrotizing soft tissue infection (NSTI). Accordingly, we investigated the association between plasma nitrite level at admission and the presence of septic shock in patients with NSTI. We also evaluated the association between nitrite, asymmetric dimethylarginine (ADMA), L-arginine, L-arginine/ADMA ratio, and outcome. METHODS: We analyzed plasma from 141 NSTI patients taken upon hospital admission. The severity of NSTI was assessed by the presence of septic shock, Simplified Acute Physiology Score (SAPS) II, Sepsis-Related Organ Failure Assessment (SOFA) score, use of renal replacement therapy (RRT), amputation, and 28-day mortality. RESULTS: No difference in nitrite levels was found between patients with and without septic shock (median 0.82 µmol/L [interquartile range (IQR) 0.41-1.21] vs. 0.87 µmol/L (0.62-1.24), P = 0.25). ADMA level was higher in patients in need of RRT (0.64 µmol/L (IQR 0.47-0.90) vs. (0.52 µmol/L (0.34-0.70), P = 0.028), and ADMA levels correlated positively with SAPS II (rho = 0.32, P = 0.0002) and SOFA scores (rho = 0.22, P = 0.01). In a logistic regression analysis, an L-arginine/ADMA ratio below 101.59 was independently associated with 28-day mortality, odds ratio 6.03 (95% confidence interval, 1.41-25.84), P = 0.016. None of the other analyses indicated differences in the NO system based on differences in disease severity. CONCLUSIONS: In patients with NSTI, we found no difference in baseline nitrite levels according to septic shock. High baseline ADMA level was associated with the use of RRT and patients with a low baseline L-arginine/ADMA ratio were at higher risk of dying within 28 days after hospital admission.

The role of nonsteroidal anti-inflammatory drugs intramuscular injection in the development and severity of deep soft tissue infection in mice.

The aim of this study was to determine the role of nonsteroidal anti-inflammatory drugs (NSAID) injection on the severity of local infection and the effect on the progression of soft tissue infection (STI).The mouse model of STI with Group A streptococcus (GAS) was developed and treated with diclofenac sodium (DS) intramuscularly. Mice were divided into five groups: administered DS for 48 h before GAS (Group 1), GAS-DS and maintained DS for 48 h (Group 2), DS for 48 h (Group 3), GAS on zero time (Group 4), and control (Group 5). In vitro, a high concentration (40 mg/L) of DS inhibited GAS growth, whereas a lower concentration (0.4 mg/L) was not effective. Sepsis was observed in animals with DS and GAS inoculation (group 1 and 2). Group 4 had statistically significant higher bacterial load than groups 1 and 2. All groups had a higher inflammation rate than the control group. The median of TNF-alpha and mean IL-6 in the groups 1, 2, and 4 was significantly higher than those in the control group. Even if the animals that were treated with DS injection prior to the GAS inoculation had similar inflammation score, similar cytokine levels and low bacterial load in the tissue, they had a rather high rate of sepsis. In conclusion, DS injection prior to bacterial inoculation might predispose to bacteremia and sepsis.

Procalcitonin as a diagnostic and prognostic marker in diabetic foot infection. A current literature review.

Diabetic foot ulcers (DFUs) are a very common cause of mortality and morbidity. The distinction between infected and non-infected DFU remains a very challenging task for clinicians in everyday practice. Even when infection is documented, the spectrum of diabetic foot infection is wide, ranging from cellulitis and soft tissue infection to osteomyelitis. Procalcitonin (PCT), a well-established sepsis biomarker, has been used in the diagnosis of several infections including osteomyelitis in patients with diabetes mellitus. This review gathers and presents all the relevant data, up until now, regarding the use of PCT as an assessment tool in diabetic patients with foot infection. Current evidence suggests that PCT levels could aid clinicians in distinguishing infected from non-infected DFUs as well as in the distinction between soft tissue infection and bone involvement, but further and larger studies are warranted to confirm these findings.

Biomarkers of Necrotising Soft Tissue Infections Aspects of the Innate Immune Response.

Necrotising soft tissue infection (NSTI) is a life-threatening and rapidly progressing bacterial infection involving one or more layers of the soft tissue compartments causing necrosis. The amputation and mortality rates remain high despite increased focus on the patients. Timely treatment, including surgical intervention, reduces the risk of severe disability and death. However, the lack of pathognomonic signs impedes early diagnosis and treatment. Moreover, the rarity of the disease makes it difficult to conduct large prospective studies, thus prospective research is almost non-existent in this group of patients. Instead data regarding biomarkers are extrapolated from the wide and heterogenic group of patients with sepsis, even though the immunological responses are likely to differ because of the large amount of necrotic tissue seen in patients with NSTI.   We performed the largest prospective, observational studies to date of patients with NSTI in Scandinavia sampled over more than two years with up to a 2.7-year follow-up. Blood samples were taken on admission (baseline) and the following three days and subsequently analysed for relevant plasma biomarkers. We elaborated on three aspects of the innate immune response, which included the investigation of acute-phase proteins, pattern recognition molecules of the lectin complement pathway, and inflammatory cytokines. The objective was to investigate aspects of the innate immune response in patients with NSTI, focusing on biomarkers as prognostic markers of disease severity and mortality. The overall hypothesis was that plasma biomarkers, representing the early innate immune response, can be used as prognostic markers of disease severity and mortality assessed by ICU scoring systems (SAPS II and SOFA score), the Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC) score, presence of septic shock, microbial aetiology, renal replacement therapy, and amputation.   In Study 1, we assessed the following acute-phase proteins in 135 patients with NSTI: pentraxin-3 (PTX3), procalcitonin, and C-reactive protein. We found that a high baseline PTX3 level above the median was significantly associated with the presence of septic shock, amputation, and 180-day mortality, albeit PTX3 was not an independent predictor of mortality. PTX3 and procalcitonin performed equally well, whereas C-reactive protein correlated poorly with clinically relevant outcomes.      In Study 2, we assessed the following plasma pattern recognition molecules in the same cohort as in Study 1: mannose-binding lectin, Ficolin-1, Ficolin-2, and Ficolin-3. We found that baseline Ficolin-2 level below the median was associated with short- and long-term mortality and correlated with the SAPS II, whereas low levels of mannose-binding lectin and Ficolin-3 were associated only with short-term mortality.   In Study 3, we assessed the following inflammatory cytokines in 159 patients with NSTI: interleukin-1ß, interleukin-6, interleukin-10, and tumor necrosis factor-α. We found no significant association between the LRINEC score and baseline cytokine levels. In addition, interleukin-6 had the strongest correlation with the disease severity scores (SAPS II and SOFA score), whereas interleukin-1ß and interleukin-10 had the strongest association with 30-day mortality. Moreover, patients with ß-haemolytic streptococcal infection had higher levels of interleukin-6 and tumor necrosis factor-α compared with each subgroup stratified by microbial aetiology.    This thesis provides new knowledge on the aspects of the innate immune response in patients with NSTI. The results prove that NSTI is characterised by a pronounced inflammatory response and that the innate immune response differs according to disease severity, microbial aetiology, and mortality. Through the three studies we have identified relevant biomarkers that are useful in the risk stratification of patients with NSTI, thus perhaps enhancing prognostication and decision making in these critically ill patients.

Evaluating the Laboratory Risk Indicator to Differentiate Cellulitis from Necrotizing Fasciitis in the Emergency Department.

INTRODUCTION: Necrotizing fasciitis (NF) is an uncommon but rapidly progressive infection that results in gross morbidity and mortality if not treated in its early stages. The Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC) score is used to distinguish NF from other soft tissue infections such as cellulitis or abscess. This study analyzed the ability of the LRINEC score to accurately rule out NF in patients who were confirmed to have cellulitis, as well as the capability to differentiate cellulitis from NF. METHODS: This was a 10-year retrospective chart-review study that included emergency department (ED) patients ≥18 years old with a diagnosis of cellulitis or NF. We calculated a LRINEC score ranging from 0-13 for each patient with all pertinent laboratory values. Three categories were developed per the original LRINEC score guidelines denoting NF risk stratification: high risk (LRINEC score ≥8), moderate risk (LRINEC score 6-7), and low risk (LRINEC score ≤5). All cases missing laboratory values were due to the absence of a C-reactive protein (CRP) value. Since the score for a negative or positive CRP value for the LRINEC score was 0 or 4 respectively, a LRINEC score of 0 or 1 without a CRP value would have placed the patient in the "low risk" group and a LRINEC score of 8 or greater without CRP value would have placed the patient in the "high risk" group. These patients missing CRP values were added to these respective groups. RESULTS: Among the 948 ED patients with cellulitis, more than one-tenth (10.7%, n=102 of 948) were moderate or high risk for NF based on LRINEC score. Of the 135 ED patients with a diagnosis of NF, 22 patients had valid CRP laboratory values and LRINEC scores were calculated. Among the other 113 patients without CRP values, six patients had a LRINEC score ≥ 8, and 19 patients had a LRINEC score ≤ 1. Thus, a total of 47 patients were further classified based on LRINEC score without a CRP value. More than half of the NF group (63.8%, n=30 of 47) had a low risk based on LRINEC ≤5. Moreover, LRINEC appeared to perform better in the diabetes population than in the non-diabetes population. CONCLUSION: The LRINEC score may not be an accurate tool for NF risk stratification and differentiation between cellulitis and NF in the ED setting. This decision instrument demonstrated a high false positive rate when determining NF risk stratification in confirmed cases of cellulitis and a high false negative rate in cases of confirmed NF.

NEW METHOD OF TREATMENT OF PYOINFLAMMATORY SOFT TISSUE COMPLICATIONS IN PATIENTS WITH DIABETES MELLITUS.

Our study evaluated the levels of peroxide oxidation of lipids, oxidative modification of proteins, antioxidant protection and dynamic changes in markers of toxicity in patients with diabetes mellitus and purulent-inflammatory complications. In total, 124 patients were enrolled in the study and were divided into two groups according the treatment methods. Study group consisted of 53 patients, who received intravenously ozonized saline in addition to conservative treatment. The control group consisted of 71 patients who received only conventional therapy. The study period was 6-15 days. The results showed that the use of ozone therapy is not accompanied by negative injury responses at the level of hemostasis parameters and blood biochemical characteristics. Furthermore, ozone therapy may have a favorable effect on treatment outcome in patients with purulent-inflammatory complications and daibetes mellitus.