Intravenous immunoglobulin G therapy in streptococcal toxic shock syndrome: a European randomized, double-blind, placebo-controlled trial

The intricate pathogenicity of group a Streptococcus: A comprehensive update

Group A Streptococcus (GAS) is a versatile pathogen that targets human lymphoid, decidual, skin, and soft tissues. Recent advancements have shed light on its airborne transmission, lymphatic spread, and interactions with neuronal systems. GAS promotes severe inflammation through mechanisms involving inflammasomes, IL-1β, and T-cell hyperactivation. Additionally, it secretes factors that directly induce skin necrosis via Gasdermin activation and sustains survival and replication in human blood through sophisticated immune evasion strategies. These include lysis of erythrocytes, using red cell membranes for camouflage, resisting antimicrobial peptides, evading phagocytosis, escaping from neutrophil extracellular traps (NETs), inactivating chemokines, and cleaving targeted antibodies. GAS also employs molecular mimicry to traverse connective tissues undetected and exploits the host's fibrinolytic system, which contributes to its stealth and potential for causing autoimmune conditions after repeated infections. Secreted toxins disrupt host cell membranes, enhancing intracellular survival and directly activating nociceptor neurons to induce pain. Remarkably, GAS possesses mechanisms for precise genome editing to defend against phages, and its fibrinolytic capabilities have found applications in medicine. Immune responses to GAS are paradoxical: robust responses to its virulence factors correlate with more severe disease, whereas recurrent infections often show diminished immune reactions. This review focuses on the multifaceted virulence of GAS and introduces novel concepts in understanding its pathogenicity.

Chains of misery: surging invasive group A streptococcal disease

PURPOSE OF REVIEW

We describe the epidemiology of the recent global surge in invasive group A streptococcal (GAS) disease and consider its proximate and distal causes. We highlight important knowledge gaps regarding clinical management and discuss potential strategies for prevention.

RECENT FINDINGS

Rates of invasive GAS (iGAS) disease were increasing globally prior to the COVID-19 pandemic. Since mid-2022, following the worst years of the pandemic in 2020 and 2021, many countries with systems to monitor GAS syndromes have reported surges in cases of iGAS concurrent with increased scarlet fever, pharyngitis, and viral co-infections. The emergence of the hypervirulent M1UK strain as a cause of iGAS, particularly in high income countries, is concerning. New data are emerging on the transmission dynamics of GAS. GAS remains universally susceptible to penicillin but there are increasing reports of macrolide and lincosamide resistance, particularly in invasive isolates, with uncertain clinical consequences. Intravenous immunoglobulin is used widely for streptococcal toxic shock syndrome and necrotizing soft tissue infections, although there is limited clinical evidence, and none from a completed randomized controlled trial. Intensive and expensive efforts at population-level control of GAS infections and postinfectious autoimmune complications have been only partially successful. The great hope for control of GAS diseases remains vaccine development. However, all modern vaccine candidates remain in the early development stage.

SUMMARY

In many countries, iGAS rates surged from mid-2022 in the aftermath of pandemic control measures and physical distancing. The emergence of a dominant hypervirulent strain is an important but incomplete explanation for this phenomenon. Clinical management of iGAS remains highly empirical and new data has not emerged. A vaccine remains the most likely means of achieving a sustainable reduction in the burden of iGAS.

Structural insights into the binding of nanobodies to the Staphylococcal enterotoxin B

Staphylococcal Enterotoxin Type B (SEB), produced by Staphylococcus aureus bacteria, is notorious for inducing severe food poisoning and toxic shock syndrome. While nanobody-based treatments hold promises for combating SEB-induced diseases, the lack of structural information between SEB and nanobodies has hindered the development of nanobody-based therapeutics. Here, we present crystal structures of SEB-Nb3, SEB-Nb6, SEB-Nb8, SEB-Nb11, and SEB-Nb20 at resolutions ranging from 1.59 Å to 2.33 Å. Crystallographic analysis revealed that Nb3, Nb8, Nb11, and Nb20 bind to SEB at the T-cell receptor (TCR) interface, while Nb6 binds at the major histocompatibility complex (MHC) interface, suggesting their potential to inhibit SEB function by disrupting interactions with TCR or MHC molecules. Molecular biological analyses confirmed the thermodynamic and kinetic parameters of Nb3, Nb5, Nb6, Nb8, Nb11, Nb15, Nb18, and Nb20 to SEB. The competitive inhibition was further confirmed by cell-based experiments demonstrating nanobody neutralization. These findings elucidate the structural basis for developing specific nanobodies to neutralize SEB threats, providing crucial insights into the underlying mechanisms and offering significant assistance for further optimization towards future therapeutic strategies.

High-dose intravenous immunoglobulin versus albumin 4% in paediatric toxic shock syndrome: a randomised controlled feasibility study

PURPOSE

Toxic shock syndrome (TSS) is a rare disease responsible for significant morbidity and mortality. Intravenous immunoglobulin (IG) therapy in paediatric TSS could improve shock and organ failure, but more consistent efficacy and safety data are needed. Our objective was to determine whether a randomised clinical trial (RCT) assessing intravenous IG in TSS in children is feasible.

METHODS

We performed a multicentre, feasibility, double-blind RCT assessing efficacy of high-dose intravenous IG versus albumin 4% (control group) within the first 12 hours of shock onset. Included patients were aged above 1 month and below 18 years with suspected TSS and septic shock. Feasibility was assessed by measuring inclusion rate, protocol compliance and missing data regarding death and the Pediatric Logistic Organ Dysfunction-2 (PELOD-2) Score. Other secondary clinical outcomes were evaluated during hospital stay, at 60 day and 1 year.

RESULTS

28 patients, admitted in 6 paediatric intensive care units during 36 consecutive months and followed for 1 year, received the allocated treatment: 13 in intravenous IG group, 15 in control group. The median age was 10.6 years and the sex ratio was 1. Inclusion rate was above 50%, protocol deviations were below 30% and missing data regarding death and PELOD-2 Score below 10%. No difference concerning secondary clinical outcomes between groups was observed, and more adverse events were reported in the control group.

CONCLUSION

It seems to be feasible to conduct an RCT assessing intravenous IG efficacy and safety in paediatric TSS but must be realised internationally, with choice of a clinically relevant endpoint and a specific design in order to be realistic.

TRIAL REGISTRATION NUMBER

NCT02219165.

Novel insights into the immune response to bacterial T cell superantigens

Bacterial T cell superantigens (SAgs) are a family of microbial exotoxins that function to activate large numbers of T cells simultaneously. SAgs activate T cells by direct binding and crosslinking of the lateral regions of MHC class II molecules on antigen-presenting cells with T cell receptors (TCRs) on T cells; these interactions alter the normal TCR-peptide-MHC class II architecture to activate T cells in a manner that is independent of the antigen specificity of the TCR. SAgs have well-recognized, central roles in human diseases such as toxic shock syndrome and scarlet fever through their quantitative effects on the T cell response; in addition, numerous other consequences of SAg-driven T cell activation are now being recognized, including direct roles in the pathogenesis of endocarditis, bloodstream infections, skin disease and pharyngitis. In this Review, we summarize the expanding family of bacterial SAgs and how these toxins can engage highly diverse adaptive immune receptors. We highlight recent findings regarding how SAg-driven manipulation of the adaptive immune response may operate in multiple human diseases, as well as contributing to the biology and life cycle of SAg-producing bacterial pathogens.

Toxic Shock Syndrome (TSS) Caused by Group A Streptococcus: Novel Insights Within the Context of a Familiar Clinical Syndrome

The emergence of invasive infections attributed to group A Streptococcus (GAS) infections, has resurged since the 1980s. The recent surge in reports of toxic shock syndrome due to GAS in Japan in 2024, while sensationalized in the media, does not represent a novel infectious disease per se, as its diagnosis, treatment, and prevention are already well-established. However, due to signs of increasing incidence since 2011, further research is needed. Health authorities in neighboring countries like The Republic of Korea should not only issue travel advisories but also establish meticulous surveillance systems and initiate epidemiological studies on the genotypic variations of this disease while awaiting various epidemiological research findings from Japan.

Adjunctive immunotherapeutic agents in patients with sepsis and septic shock: a multidisciplinary consensus of 23

BACKGROUND

In the last decades, several adjunctive treatments have been proposed to reduce mortality in septic shock patients. Unfortunately, mortality due to sepsis and septic shock remains elevated and NO trials evaluating adjunctive therapies were able to demonstrate any clear benefit. In light of the lack of evidence and conflicting results from previous studies, in this multidisciplinary consensus, the authors considered the rational, recent investigations and potential clinical benefits of targeted adjunctive therapies.

METHODS

A panel of multidisciplinary experts defined clinical phenotypes, treatments and outcomes of greater interest in the field of adjunctive therapies for sepsis and septic shock. After an extensive systematic literature review, the appropriateness of each treatment for each clinical phenotype was determined using the modified RAND/UCLA appropriateness method.

RESULTS

The consensus identified two distinct clinical phenotypes: patients with overwhelming shock and patients with immune paralysis. Six different adjunctive treatments were considered the most frequently used and promising: (i) corticosteroids, (ii) blood purification, (iii) immunoglobulins, (iv) granulocyte/monocyte colony-stimulating factor and (v) specific immune therapy (i.e. interferon-gamma, IL7 and AntiPD1). Agreement was achieved in 70% of the 25 clinical questions.

CONCLUSIONS

Although clinical evidence is lacking, adjunctive therapies are often employed in the treatment of sepsis. To address this gap in knowledge, a panel of national experts has provided a structured consensus on the appropriate use of these treatments in clinical practice.

The Thousand Faces of Invasive Group A Streptococcal Infections: Update on Epidemiology, Symptoms, and Therapy

Invasive infections caused by Streptococcus pyogfenes (iGAS), commonly known as Group A Streptococcus, represent a significant public health concern due to their potential for rapid progression and life-threatening complications. Epidemiologically, invasive GAS infections exhibit a diverse global distribution, affecting individuals of all ages with varying predisposing factors. The pathogenesis of invasive GAS involves an array of virulence factors that contribute to tissue invasion, immune evasion, and systemic dissemination. In pediatrics, in the last few years, an increase in iGAS infections has been reported worldwide becoming a challenging disease to diagnose and treat promptly. This review highlights the current knowledge on pathogenesis, clinical presentations, and therapeutic approaches for iGAS in children.

Toxic Shock Syndrome: A Literature Review

Toxic shock syndrome (TSS) is a rare, life-threatening, toxin-mediated infectious process linked, in the vast majority of cases, to toxin-producing strains of Staphylococcus aureus or Streptococcus pyogenes. The pathophysiology, epidemiology, clinical presentation, microbiological features, management and outcome of TSS are described in this review. Bacterial superantigenic exotoxins induces unconventional polyclonal lymphocyte activation, which leads to rapid shock, multiple organ failure syndrome, and death. The main described superantigenic exotoxins are toxic shock syndrome toxin-1 (TSST-1) and enterotoxins for Staphylococcus aureus and Streptococcal pyrogenic exotoxins (SpE) A, B, and C and streptococcal superantigen A (SsA) for Streptococcus pyogenes. Staphylococcal TSS can be menstrual or nonmenstrual. Streptococcal TSS is linked to a severe group A streptococcal infection and, most frequently, to a necrotizing soft tissue infection. Management of TSS is a medical emergency and relies on early detection, immediate resuscitation, source control and eradication of toxin production, bactericidal antibiotic treatment, and protein synthesis inhibiting antibiotic administration. The interest of polyclonal intravenous immunoglobulin G administration as an adjunctive treatment for TSS requires further evaluation. Scientific literature on TSS mainly consists of observational studies, clinical cases, and in vitro data; although more data on TSS are required, additional studies will be difficult to conduct due to the low incidence of the disease.

Effect of intravenous immunoglobulin on the outcome of children with septic shock in a PICU: a retrospective cohort study

The therapeutic efficacy of intravenous immuneglobulin (IVIG) on children with septic shock remains uncertain. Therefore, we endeavored to investigate the impact of administering intravenous immunoglobulin (IVIG) in the pediatric intensive care unit (PICU) on patient with septic shock. We retrospectively analyzed the data of children admitted to the PICU due to septic shock from January 2017 to December 2021 in a tertiary pediatric hospital. The main outcome was in-hospital mortality. Total 304 patients were enrolled. There were no significant differences in the PRISM-III score (11 vs. 12, P = 0.907), PIM-3 score (0.08 vs. 0.07, P = 0.544), pSOFA score (10 vs. 10, P = 0.852) between the No IVIG group and the IVIG group. Children who received IVIG required more continuous renal replacement therapy (CRRT) support (43% vs. 24%, P = 0.001) and longer duration of mechanical ventilation (MV) (6 vs. 3 days, P = 0.002), and longer length of stay (LOS) of PICU (7 vs. 4 days, P = 0.001) and LOS of hospital (18 vs. 11 days, P = 0.001) than children who did not receive. The 28-day survival analysis (P = 0.033) showed better survival rates in IVIG group, while the in-hospital mortality (43% vs. 52%, P = 0.136) was no significant difference. In the propensity score matched analysis, 71 pairs were established. The length of CRRT (2 vs. 3 days, P = 0.744), duration of mechanical ventilation (5 vs. 4 days, P = 0.402), LOS of PICU (7 vs. 5 days, P = 0.216), LOS of hospital (18 vs. 13 days, P = 0.290), in-hospital mortality (44% vs. 44%, P = 1.000) and 28-day survival analysis (P = 0.748) were not statistically different. After inverse probability weighted analysis, there was still no difference in mortality between the two groups (51% vs. 48%, P = 0.665).

CONCLUSION

In children with septic shock, the use of intravenous immunoglobulin as an adjuvant therapy does not reduce in-hospital mortality.

WHAT IS KNOWN

• Guidelines suggest against the routine use of intravenous immuneglobulin in children with septic shock. Some small observational studies have reported conflicting result.

WHAT IS NEW

• The use of intravenous immunoglobulin as an adjuvant therapy does not reduce in-hospital mortality in children with septic shock.

Multifaceted Tissue-Protective Functions of Polyvalent Immunoglobulin Preparations in Severe Infections-Interactions with Neutrophils, Complement, and Coagulation Pathways

Severe infections induce immune defense mechanisms and initial tissue damage, which produce an inflammatory neutrophil response. Upon dysregulation of these responses, inflammation, further tissue damage, and systemic spread of the pathogen may occur. Subsequent vascular inflammation and activation of coagulation processes may cause microvascular obstruction at sites distal to the primary site of infection. Low immunoglobulin (Ig) M and IgG levels have been detected in patients with severe infections like sCAP and sepsis, associated with increased severity and mortality. Based on Ig's modes of action, supplementation with polyvalent intravenous Ig preparations (standard IVIg or IgM/IgA-enriched Ig preparations) has long been discussed as a treatment option for severe infections. A prerequisite seems to be the timely administration of Ig preparations before excessive tissue damage has occurred and coagulopathy has developed. This review focuses on nonclinical and clinical studies that evaluated tissue-protective activities resulting from interactions of Igs with neutrophils, complement, and the coagulation system. The data indicate that coagulopathy, organ failure, and even death of patients can possibly be prevented by the timely combined interactions of (natural) IgM, IgA, and IgG with neutrophils and complement.

Efficacy of IVIG therapy for patients with sepsis: a systematic review and meta-analysis

BACKGROUND

Sepsis is an overwhelming reaction to infection that comes with high morbidity and mortality. It requires urgent interventions in order to improve outcomes. Intravenous immunoglobulins (IVIG) are considered as potential therapy in sepsis patients. Results of trials on IVIG as adjunctive therapy for sepsis have been conflicting due to the variability in population characteristics, country geography and drug dosage form in different studies.

METHODS

A systematic article search was performed for eligible studies published up to January, 31, 2023, through the PubMed, Embase, Cochrane Library and Chinese National Knowledge Infrastructure database. The included articles were screened by using rigorous inclusion and exclusion criteria. Subgroup analyses were conducted according to different IVIG types, ages and economic regions. All analyses were conducted using Review Manager 5.4. Quality of studies and risk of bias were evaluated.

RESULTS

In total, 31 randomized controlled trials were included with a sample size of 6,276 participants. IVIG could reduce the mortality (RR 0.86, 95% CI: 0.77-0.95, p = 0.005), the hospital stay (MD - 4.46, 95% CI: - 6.35 to - 2.57, p = 0.00001), and the APACHE II scores (MD - 1.65, 95% CI: - 2.89 to - 0.63, p = 0.001). Additionally, the results showed that IgM-enriched IVIG was effective in treating sepsis (RR 0.55, 95% CI: 0.40 - 0.76; p = 0.0003), while standard IVIG failed to be effective (RR 0.91, 95% CI: 0.81-1.02, p = 0.10). And the effect of IVIG in reducing neonatal mortality was inconclusive (RR 0.93, 95% CI: 0.81-1.05, p = 0.24), but it played a large role in reducing sepsis mortality in adults (RR 0.70, 95% CI: 0.57-0.86, p = 0.0006). Besides, from the subgroup of different economic regions, it indicated that IVIG was effective for sepsis in high-income (RR 0.89, 95% CI: 0.79-0.99, p = 0.03) and middle-income countries (RR 0.49, 95% CI: 0.28-0.84, p = 0.01), while no benefit was demonstrated in low-income countries (RR 0.56, 95% CI: 0.27-1.14, p = 0.11).

CONCLUSIONS

There is sufficient evidence to support that IVIG reduces sepsis mortality. IgM-enriched IVIG is effective in both adult and neonatal sepsis, while standard IVIG is only effective in adult sepsis. IVIG for sepsis has shown efficacy in high- and middle-income countries, but is still debatable in low-income countries. More RCTs are needed in the future to confirm the true clinical potential of IVIG for sepsis in low-income countries.

Effectiveness of intravenous immunoglobulin therapy for invasive group A Streptococcus infection: A Japanese nationwide observational study

OBJECTIVES

Invasive group A Streptococcus infection (iGAS) is a rare but fatal condition. We aimed to evaluate the effectiveness of intravenous immunoglobulin (IVIG) in the treatment of iGAS.

METHODS

Patients' data were extracted from a Japanese nationwide database between April 2018 and March 2021. The primary outcome was in-hospital mortality rate, whereas the secondary outcomes were 30-day and 7-day mortality rates.

RESULTS

Overall, 481 patients (median age, 65 years; female, 49.7%) were included in the analysis. The overall mortality rate was 31.0%. After adjusting for background factors, we found that IVIG treatment had no effect on in-hospital mortality (adjusted odds ratio [OR]: 0.99, 95% confidence interval [CI]: 0.93-1.04, P = 0.92). Similar results were obtained after propensity score matching (OR: 1.00, 95% CI: 0.62-1.61, P >0.99). The 7-day and 30-day mortality rates were not associated with IVIG treatment.

CONCLUSION

IVIG administration had no survival benefit in iGAS patients. However, these overall findings should not be extrapolated to streptococcal toxic shock syndrome as the effect of IVIG therapy in this condition remains uncertain. Considering the rarity of iGAS, conducting a randomized controlled trial may be impractical. Therefore, an equivalent or more extensive observational study is warranted to validate these findings.

Severe skin infections

PURPOSE OF REVIEW

The incidence of necrotizing soft-tissue infections (NSTI) has increased during recent decades. These infections are still associated with high morbidity and mortality, underlining a need for continued education of the medical community. This review will focus on practical approaches to management of NSTI focusing on antibiotic therapies and optimizing the management of group A streptococcus (GAS)-associated NSTIs.

RECENT FINDINGS

Antibiotic therapy for NSTI patients faces several challenges as the rapid progression of NSTIs mandates broad-spectrum agents with bactericidal action. Current recommendations support using clindamycin in combination with penicillin in case of GAS-documented NSTIs. Linezolide could be an alternative in case of clindamycin resistance.

SUMMARY

Reducing the time to diagnosis and first surgical debridement, initiating early broad-spectrum antibiotics and early referral to specialized centres are the key modifiable factors that may impact the prognosis of NSTIs. Causative organisms vary widely according to the topography of the infection, underlying conditions, and geographic location. Approximately one third of NSTIs are monomicrobial, involving mainly GAS or Staphylococcus aureus . Data for antibiotic treatment specifically for necrotizing soft-tissue infections are scarce, with guidelines mainly based on expert consensus.

Clinical Characteristics and Treatment Strategies for Group B Streptococcus (GBS) Infection in Pediatrics: A Systematic Review

Background and Objectives: Group B streptococcus (GBS) is the leading cause of infections in neonates with high fatality rates. GBS is caused by the streptococcus bacterium known as streptococcus agalactiae, which is highly contagious and can be transmitted from pregnant women to infants. GBS infection can occur as an early onset or late-onset infection and has different treatment strategies. Antibiotics are effective in treating GBS infections at early stages. The aim of this systematic review was to summarize the clinical characteristics and treatment strategies for GBS, with a focus on antibiotics. Material and Methods: The findings of this review were reported in accordance with the PRISMA 2020 guidelines and a flow diagram of the study selection process, a summary of the included studies, a description of the study characteristics, a summary of the results, a discussion of the implications of the findings, and a conclusion are included. Overall, the authors followed a rigorous methodology to ensure that this review is comprehensive and inclusive of relevant studies on GBS infection and its treatment. Results: Overall, 940 studies were reviewed and only the most relevant 22 studies were included in the systematic review. This review describes the characteristics of patients in different studies related to early onset GBS disease and presents various treatment strategies and outcomes for GBS infection in pediatrics. The studies suggest that preventive measures, risk-based intrapartum antibiotic prophylaxis, and maternal vaccination can significantly reduce the burden of GBS disease, but late-onset GBS disease remains a concern, and more strategies are required to decrease its rate. Improvement is needed in the management of the risk factors of GBS. A conjugate vaccine with a serotype (Ia, Ib, II, III, and V) has been proven effective in the prevention of GBS in neonates. Moreover, penicillin is an important core antibiotic for treating early onset GBS (EOD). Conclusions: This systematic review summarizes the treatment comparison for GBS infections in neonates, with a primary focus on antibiotics. IAP (intrapartum antibiotic prophylaxis) according to guidelines, antenatal screening, and the development of a conjugate vaccine may be effective and could lower the incidence of the disease.

Necrotizing Fasciitis-Severe Complication of Bullous Pemphigoid: A Systematic Review, Risk Factors, and Treatment Challenges

Background and objectives: Bullous pemphigoid (BP), the most common subepidermal autoimmune skin blistering disease (AIBD) has an estimated annual incidence of 2.4 to 42.8 new cases per million in different populations, designating it an orphan disease. Characterized by disruption of the skin barrier combined with therapy-induced immunosuppression, BP could pose a risk for skin and soft tissue infections (SSTI). Necrotizing fasciitis (NF) is a rare necrotizing skin and soft tissue infection, with a prevalence of 0.40 cases per 100,000 to 15.5 cases per 100,000 population, often associated with immunosuppression. Low incidences of NF and BP classify them both as rare diseases, possibly contributing to the false inability of making a significant correlation between the two. Here, we present a systematic review of the existing literature related to the ways these two diseases correlate. Materials and methods: This systematic review was conducted according to the PRISMA guidelines. The literature review was conducted using PubMed (MEDLINE), Google Scholar, and SCOPUS databases. The primary outcome was prevalence of NF in BP patients, while the secondary outcome was prevalence and mortality of SSTI in BP patients. Due to the scarcity of data, case reports were also included. Results: A total of 13 studies were included, six case reports of BP complicated by NF with six retrospective studies and one randomized multicenter trial of SSTIs in BP patients. Conclusions: Loss of skin integrity, immunosuppressive therapy, and comorbidities commonly related to BP patients are risk factors for necrotizing fasciitis. Evidence of their significant correlation is emerging, and further studies are deemed necessary for the development of BP-specific diagnostic and treatment protocols.

Outcomes and management of pregnancy and puerperal group A streptococcal infections: A systematic review

INTRODUCTION

Group A streptococcus (Streptococcus pyogenes) is one of the most lethal bacterial pathogens of humans, with increased risk of progression to septic shock and multiorgan failure in the pregnant population. The objective of this study is to systematically review the outcomes and management strategies for pregnancy and puerperal group A streptococcus infections in an effort to provide further guidance for prevention and treatment of a rare but lethal infection worldwide.

MATERIAL AND METHODS

A comprehensive search using puerperium and streptococcus pyogenes terms was completed across several registered databases. A total of 902 articles investigating pregnancy and puerperal group A streptococcus infection were identified, with 40 studies fulfilling inclusion criteria of original research articles in humans published from 1990 onwards reporting four or more unique cases of group A streptococcus in pregnancy or postpartum. This study was registered in PROSPERO: CRD42020198983.

RESULTS

A total of 1160 patients with pregnancy and puerperal group A streptococcus infection were identified. Most infections occurred postpartum (91.9%), with 4.7% reported antepartum and 0.6% intrapartum. Bacteremia was present in 49.0% of patients and endometritis in 45.9%. Puerperal sepsis was described in 28.2% of cases and progressed to streptococcal toxic shock syndrome in one-third of such cases. Overall, the case fatality ratio was 2.0%, with one-third of the deaths from antenatal cases including 3/22 (13.6%) cases of septic abortion and 10/46 (21.7%) antenatal cases of group A streptococcus infection.

CONCLUSIONS

Group A streptococcus infection remains an important contributor to pregnancy and puerperal morbidity and mortality. Early recognition, diagnosis and aggressive management are important for favorable outcomes given the serious risk of sepsis and streptococcal toxic shock syndrome.

Polyvalent human immunoglobulin for infectious diseases: Potential to circumvent antimicrobial resistance

Antimicrobial resistance (AMR) is a global health problem that causes more than 1.27 million deaths annually; therefore, it is urgent to focus efforts on solving or reducing this problem. The major causes of AMR are the misuse of antibiotics and antimicrobials in agriculture, veterinary medicine, and human medicine, which favors the selection of drug-resistant microbes. One of the strategies proposed to overcome the problem of AMR is to use polyvalent human immunoglobulin or IVIG. The main advantage of this classic form of passive immunization is its capacity to enhance natural immunity mechanisms to eliminate bacteria, viruses, or fungi safely and physiologically. Experimental data suggest that, for some infections, local administration of IVIG may produce better results with a lower dose than intravenous application. This review presents evidence supporting the use of polyvalent human immunoglobulin in AMR, and the potential and challenges associated with its proposed usage.

Prognostic factors for streptococcal toxic shock syndrome: systematic review and meta-analysis

OBJECTIVES

To quantify the prognostic effects of demographic and modifiable factors in streptococcal toxic shock syndrome (STSS).

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

MEDLINE, EMBASE and CINAHL from inception to 19 September 2022, along with citations of included studies.

ELIGIBILITY CRITERIA

Pairs of reviewers independently screened potentially eligible studies of patients with Group A Streptococcus-induced STSS that quantified the association between at least one prognostic factor and outcome of interest.

DATA EXTRACTION AND SYNTHESIS

We performed random-effects meta-analysis after duplicate data extraction and risk of bias assessments. We rated the certainty of evidence using the Grading of Recommendations, Assessment, Development and Evaluation approach.

RESULTS

One randomised trial and 40 observational studies were eligible (n=1918 patients). We found a statistically significant association between clindamycin treatment and mortality (n=144; OR 0.14, 95% CI 0.06 to 0.37), but the certainty of evidence was low. Within clindamycin-treated STSS patients, we found a statistically significant association between intravenous Ig treatment and mortality (n=188; OR 0.34, 95% CI 0.15 to 0.75), but the certainty of evidence was also low. The odds of mortality may increase in patients ≥65 years when compared with patients 18-64 years (n=396; OR 2.37, 95% CI 1.47 to 3.84), but the certainty of evidence was low. We are uncertain whether non-steroidal anti-inflammatory drugs increase the odds of mortality (n=50; OR 4.14, 95% CI 1.13 to 15.14; very low certainty). Results failed to show a significant association between any other prognostic factor and outcome combination (very low to low certainty evidence) and no studies quantified the association between a prognostic factor and morbidity post-infection in STSS survivors.

CONCLUSIONS

Treatment with clindamycin and within clindamycin-treated patients, IVIG, was each significantly associated with mortality, but the certainty of evidence was low. Future research should focus on morbidity post-infection in STSS survivors.

PROSPERO REGISTRATION NUMBER

CRD42020166961.

Toxic Shock Syndrome From Group C Streptococcus

We present a patient who was admitted with lower extremity cellulitis and was found to have Group C Streptococcus bacteremia causing toxic shock syndrome. Our patient was started on appropriate antibiotics, which included piperacillin/tazobactam, vancomycin, and clindamycin for presumed cellulitis, and was later transitioned to meropenem on day two when she was found to have gram-positive group C bacteremia and was treated for 14 days. Additionally, she was initiated on a three-day regimen of intravenous immunoglobulin (IVIG) as an adjunctive treatment for worsening clinical status from toxic shock syndrome. Our patient survived up to 46 days post admission but ultimately succumbed to her illness. It is worthwhile to state that the addition of IVIG could have prolonged her survival. We emphasize the importance of timely diagnosis and treatment with antibiotics and IVIG to help prevent mortality from this condition. 

Acute abdomen: a rare presentation of group a streptococcal infection

In this case report we describe a 38-year old female patient admitted to the emergency department with acute abdomen and sepsis. Broad-spectrum antibiotics were started. Abdominal imaging was inconclusive, exploratory laparoscopy showed four-quadrant peritonitis. No provoking factor could be withheld. Due to clinical deterioration the patient was transferred to the intensive care unit. Blood cultures showed the presence of group A streptococcus, and clindamycin was associated. She recovered, and could be discharged after several days. Peritonitis caused by group A Streptococcus pyogenes is rare in healthy individuals, and occurs mostly in middle-aged women. There is no consensus regarding surgical treatment but surgical exploration is often necessary to exclude secondary peritonitis. Treatment with broad-spectrum antibiotics and supportive measurements remain the cornerstone in patient management. Association of clindamycin has been shown to reduce mortality. There is inconclusive evidence to support Intravenous polyspecific immunoglobulin G (IVIG) therapy in streptococcal toxic shock syndrome.

Case Report: Therapeutic Strategy With Delayed Debridement for Culture-Negative Invasive Group A Streptococcal Infections Diagnosed by Metagenomic Next-Generation Sequencing

Streptococcal toxic shock syndrome (STSS) caused by group A streptococcus is a rare condition that rapidly developed to multiple organ failure even death. Therefore, prompt diagnosis, initiate appropriate antibiotics and other supportive treatments are critical. Here we reported a case of STSS caused by group A streptococcus infection. A healthy 39-year-old man presented a sudden pain in the left lower extremity, followed by a high fever (40.0 °C) with dizziness, nausea, and shortness of breath. Twenty-four hours before the visit, the patient showed anuria. The patient was then admitted to the intensive care unit. Blood examination revealed elevated levels of inflammatory markers and creatinine. He suffered from septic shock, dysfunction of coagulation, acute kidney dysfunction, acute respiratory distress syndrome, and acute liver function injury. The diagnosis was obtained through clinical manifestation and metagenomic next-generation sequencing (mNGS) drawn from the pustule and deep soft tissue (lower limb) samples while all bacterial cultures came back negative. The pustule mNGS report detected a total of 132 unique group A streptococcus sequence reads, representing 96.3% of microbial reads while the soft tissue mNGS report identified a total of 142474 unique group A streptococcus sequence reads, representing 100% of microbial reads. The patient was treated with aggressive fluid resuscitation, antibiotics comprising piperacillin/tazobactam and clindamycin, respiratory support, following the delayed surgical debridement. Intravenous immunoglobulin was also used for 5 days. On the 14th day after admission, he was transferred to the general ward for follow-up treatment. Our case highlighted, for the first time, the key role of mNGS in the early diagnosis of culture-negative invasive group A streptococcal infection. The case also suggested that clindamycin combined with beta-lactam antibiotics and adjunction of intravenous immunoglobulin therapy with delayed debridement performed well in the management of unstable STSS patients.

The importance of intravenous immunoglobulin treatment in critically ill patients with necrotizing soft tissue infection: a retrospective cohort study

Background

Necrotizing soft-tissue infections are infections with high mortality. The use of immunoglobulins within a combination therapy including broad-spectrum antibiotics has been debated. We assessed potential benefits of immunoglobulins and hypothesized that they were associated with a treatment benefit in a high-resource setting.

Methods

Patients with necrotizing soft-tissue infection hospitalized in the tertiary intensive care unit of the University Hospital of Zurich, Switzerland, between 2008 and 2020 were included retrospectively. The association between immunoglobulin administration and in-hospital survival, intensive care unit length of stay, the incidences of acute renal failure, acute respiratory distress syndrome and septic shock were analyzed.

Results

After adjustment for confounders, no difference for in-hospital survival (hazard ratio 2.20, 95% confidence interval [CI] 0.24–20.20, p = 0.5), intensive care unit length of stay (subhazard ratio [SHR] 0.90, CI 0.41–1.98, p = 0.8) and the development of acute respiratory distress syndrome (SHR 1.2, CI 0.36–4.03, p = 0.77) was observed in patients with or without immunoglobulin treatment. The Simplified Acute Physiology Score II, the risk of developing acute renal failure (SHR 2.86, CI 1.33–6.15, p = 0.01) and septic shock (SHR 1.86, CI 1.02–3.40, p = 0.04) was higher in patients treated with immunoglobulins, possibly reflecting a higher disease severity beyond measured confounders.

Conclusions

No clear evidence for a benefit of immunoglobulins in our cohort with consistent antibiotic use was found. Patients receiving immunoglobulins appeared more severely ill. Complementary to high treatment standards and appropriate antibiotics including beta lactams and protein synthesis inhibitors, immunoglobulins should be administered on a case-to-case basis, at least while more evidence from larger randomized controlled trials is missing.

Severe Skin and Soft-Tissue Infections

Skin and soft-tissue infections (SSTIs) are a common reason for hospital admission. Severe SSTIs, particularly necrotizing infections, often require intensive care. Source control (often with surgical debridement) and broad-spectrum antimicrobials are paramount for minimizing significant morbidity and mortality. Rapid diagnostic tests may help in selection and de-escalation of antimicrobials for SSTIs. Besides early source control and early effective antimicrobial therapy, other patient-level factors such as comorbidities and immune status play a role in clinical outcomes. Intravenous immunoglobulin continues to be studied for severe SSTI, though recruitment in trials continues to be an issue. Severe SSTIs are complex to manage, due in part to regional variation in predominant pathogens and antimicrobial resistance patterns, as well as variations in host immune responses. This review includes descriptions of source control, antimicrobial therapies, intravenous immunoglobulin, and hyperbaric oxygen therapy, as well as host factors in severe SSTIs.

Necrotizing Soft Tissue Infections: More than What Meets the Eye

How to cite this article: Kundu R, Srinivasan S. Necrotizing Soft Tissue Infections: More than What Meets the Eye. Indian J Crit Care Med 2022;26(4):411-413.

Antibiotic Treatment, Mechanisms for Failure, and Adjunctive Therapies for Infections by Group A Streptococcus

Group A Streptococcus (GAS; Streptococcus pyogenes) is a nearly ubiquitous human pathogen responsible for a significant global disease burden. No vaccine exists, so antibiotics are essential for effective treatment. Despite a lower incidence of antimicrobial resistance than many pathogens, GAS is still a top 10 cause of death due to infections worldwide. The morbidity and mortality are primarily a consequence of the immune sequelae and invasive infections that are difficult to treat with antibiotics. GAS has remained susceptible to penicillin and other β-lactams, despite their widespread use for 80 years. However, the failure of treatment for invasive infections with penicillin has been consistently reported since the introduction of antibiotics, and strains with reduced susceptibility to β-lactams have emerged. Furthermore, isolates responsible for outbreaks of severe infections are increasingly resistant to other antibiotics of choice, such as clindamycin and macrolides. This review focuses on the challenges in the treatment of GAS infection, the mechanisms that contribute to antibiotic failure, and adjunctive therapeutics. Further understanding of these processes will be necessary for improving the treatment of high-risk GAS infections and surveillance for non-susceptible or resistant isolates. These insights will also help guide treatments against other leading pathogens for which conventional antibiotic strategies are increasingly failing.

Effect of immunoglobulin G on cytokine response in necrotising soft-tissue infection: A post hoc analysis

BACKGROUND

A marked inflammatory response in necrotising soft-tissue infection (NSTI) may contribute to the severe clinical course. Intravenous polyspecific immunoglobulin G (IVIG) is used by some as adjuvant treatment for NSTI, but in the randomised INSTINCT trial, no effect of IVIG in NSTI patients was seen on physical quality of life. In experimental studies, IVIG may induce immunosuppressive effects by reducing the pro-inflammatory response and neutralising circulating superantigens. However, data on the potential immunomodulatory effects are sparse and remain to be investigated in a clinical setting. In this post hoc analysis of the INSTINCT trial, we aimed to assess the effect of IVIG on various inflammatory cytokines up to day 3 after randomisation.

METHODS

Tumour necrosis factor (TNF), interleukin-1β, interleukin-6, interleukin-10 and granulocyte colony-stimulating factor were measured at admission, days 1, 2 and 3.

RESULTS

A total of 100 ICU patients with NSTI were included; 50 were allocated to IVIG (25 g/d for 3 days) and 50 to placebo. No difference in the overall inflammatory response was observed between groups except from TNF, which was higher in the IVIG group as compared to the placebo group (area under curve-admission to day 3, 93.6 vs 60.2, P = .02). Similarly, no differences were observed in percentage change from baseline to day 3 in any of the studied cytokines between patients allocated to IVIG group and those allocated to placebo group.

CONCLUSION

In ICU patients with NSTI, IVIG did not reduce the plasma concentration of cytokines in the first 3 days.

Intravenous immunoglobulin and the current risk of moderate and severe anaphylactic events, a cohort study

This large cohort study from the US Premier Healthcare Database evaluated the risk and predictors of anaphylaxis in association with intravenous immunoglobulin (IvIg) therapy in the inpatient and outpatient setting. Data were collected retrospectively (January 2009-December 2018) from 24 919 patients administered IgPro10 IvIg, median age 54 years. Immunoglobulins of interest were IgPro10 and other IvIg given before or after IgPro10. Moderate and severe anaphylaxis was identified from same-day parenteral epinephrine and IvIg use and reviews of patient record summaries. Predictors for first anaphylactic reactions associated with IvIg administration were derived from adjusted incidence rate ratios (IRR) using Poisson regression. Moderate anaphylaxis in IvIg use was rare and severe anaphylaxis very rare based on a total of 124 moderate and four non-fatal severe first anaphylactic events, incidence rate of 7.11 and 0.23/10 000 IvIg administrations, respectively. Age under 18 years was an independent predictor of moderate or severe anaphylactic events [adjusted incidence rate ratio = 2.94, 0.95 confidence interval  = 1.91-4.52] compared with those aged 18 years and older. First IvIg administration was a strong predictor of anaphylaxis. The IRR in those with a subsequent IvIg administration in the preceding 42 days decreased to 0.27 (0.17-0.42) and in those effectively IvIg-naive (no IvIg for > 42 days) to 0.76 (0.44-1.32) compared with first IvIg use. The key conclusions from this study are that the risk of anaphylaxis has progressively reduced over the last decade, from 14.87 of 10 000 in 2009-10 to 4.39 of 10 000 IvIg administrations in 2017-18 and is rare overall, and that the risk of anaphylaxis is increased in those aged under 18 years.

The Japanese Clinical Practice Guidelines for Management of Sepsis and Septic Shock 2020 (J-SSCG 2020)

The Japanese Clinical Practice Guidelines for Management of Sepsis and Septic Shock 2020 (J-SSCG 2020), a Japanese-specific set of clinical practice guidelines for sepsis and septic shock created as revised from J-SSCG 2016 jointly by the Japanese Society of Intensive Care Medicine and the Japanese Association for Acute Medicine, was first released in September 2020 and published in February 2021. An English-language version of these guidelines was created based on the contents of the original Japanese-language version. The purpose of this guideline is to assist medical staff in making appropriate decisions to improve the prognosis of patients undergoing treatment for sepsis and septic shock. We aimed to provide high-quality guidelines that are easy to use and understand for specialists, general clinicians, and multidisciplinary medical professionals. J-SSCG 2016 took up new subjects that were not present in SSCG 2016 (e.g., ICU-acquired weakness [ICU-AW], post-intensive care syndrome [PICS], and body temperature management). The J-SSCG 2020 covered a total of 22 areas with four additional new areas (patient- and family-centered care, sepsis treatment system, neuro-intensive treatment, and stress ulcers). A total of 118 important clinical issues (clinical questions, CQs) were extracted regardless of the presence or absence of evidence. These CQs also include those that have been given particular focus within Japan. This is a large-scale guideline covering multiple fields; thus, in addition to the 25 committee members, we had the participation and support of a total of 226 members who are professionals (physicians, nurses, physiotherapists, clinical engineers, and pharmacists) and medical workers with a history of sepsis or critical illness. The GRADE method was adopted for making recommendations, and the modified Delphi method was used to determine recommendations by voting from all committee members.As a result, 79 GRADE-based recommendations, 5 Good Practice Statements (GPS), 18 expert consensuses, 27 answers to background questions (BQs), and summaries of definitions and diagnosis of sepsis were created as responses to 118 CQs. We also incorporated visual information for each CQ according to the time course of treatment, and we will also distribute this as an app. The J-SSCG 2020 is expected to be widely used as a useful bedside guideline in the field of sepsis treatment both in Japan and overseas involving multiple disciplines.

Invasive Group A Streptococcal Infections: Benefit of Clindamycin, Intravenous Immunoglobulins and Secondary Prophylaxis

Introduction: Mortality associated with invasive group A streptococcal infections (iGAS) remains high among adults, with lower mortality in children. The added value of both clindamycin and immunoglobulins in such treatment is still controversial, as is the need for antibiotic secondary prophylaxis. It is unlikely that conclusive randomized clinical studies will ever definitively end these controversies. Materials and Methods: A clinical and experimental literature review was conducted in Pubmed, Cochrane, and lay literature to determine the benefit of adding clindamycin and immunoglobulins to β-lactams in the management of iGAS, as well as the need for secondary prophylaxis measures in close contacts. Results: This review includes two meta-analyses, two randomized controlled trials, four prospective studies, five retrospective studies, and microbiological studies. To reduce mortality and morbidity, it appears useful to add clindamycin to β-lactams in severe clinical presentations, including necrotizing fasciitis or streptococcal toxic shock syndrome, and immunoglobulins for the latter two presentations. The high risk of secondary infection in household contacts justifies the need of taking preventive measures. Conclusions: Both clinical studies and available experimental evidence suggest that adding clindamycin and immunoglobulins as adjunctive therapies in the management of invasive group A streptococcal infections may reduce mortality. Household contacts should be warned about the increased risk of secondary infection, and chemoprophylaxis may be considered in certain situations.

Intravenous immune globulin in septic shock: a Canadian national survey of critical care medicine and infectious disease specialist physicians

PURPOSE

This national survey evaluated the perceived efficacy and safety of intravenous immune globulin (IVIG) in septic shock, self-reported utilization patterns, barriers to use, the population of interest for further trials and willingness to participate in future research of IVIG in septic shock.

METHODS

We conducted a cross-sectional survey of critical care and infectious diseases physicians across Canada. We summarized categorical item responses as counts and proportions. We developed a multivariable logistic regression model to identify physician-level predictors of IVIG use in septic shock.

RESULTS

Our survey was disseminated to 674 eligible respondents with a final response rate of 60%. Most (91%) respondents reported having prescribed IVIG to patients with septic shock at least once, 86% for septic shock due to necrotizing fasciitis, 52% for other bacterial toxin-mediated causes of septic shock, and 5% for undifferentiated septic shock. The majority of respondents expressed uncertainty regarding the impact of IVIG on mortality (97%) and safety (95%) in septic shock. Respondents were willing to participate in further IVIG research with 98% stating they would consider enrolling their patients into a trial of IVIG in septic shock. Familiarity with published evidence was the single greatest predictor of IVIG use in septic shock (odds ratio, 10.2; 95% confidence interval, 3.4 to 30.5; P < 0.001).

CONCLUSIONS

Most Canadian critical care and infectious diseases specialist physicians reported previous experience using IVIG in septic shock. Respondents identified inadequacy of existing research as the greatest barrier to routine use of IVIG in septic shock. Most respondents support the need for further studies on IVIG in septic shock, and would consider enrolling their own patients into a trial of IVIG in septic shock.

Intravenous immunoglobulin treatment for patients with severe COVID-19: a retrospective multicentre study

Objectives

Intravenous immunoglobulin (IVIG) is commonly used to treat severe COVID-19, although the clinical outcome of such treatment remains unclear. This study evaluated the effectiveness of IVIG treatment in severe COVID-19 patients.

Methods

This retrospective multicentre study evaluated 28-day mortality in severe COVID-19 patients with or without IVIG treatment. Each patient treated with IVIG was matched with one untreated patient. Logistic regression and inverse probability weighting (IPW) were used to control confounding factors.

Results

The study included 850 patients (421 IVIG-treated patients and 429 non-IVIG-treated patients). After matching, 406 patients per group remained. No significant difference in 28-day mortality was observed after IPW analysis (average treatment effect (ATE) = 0.008, 95% CI –0.081 to 0.097, p 0.863). There were no significant differences between the IVIG group and non-IVIG group for acute respiratory distress syndrome, diffuse intravascular coagulation, myocardial injury, acute hepatic injury, shock, acute kidney injury, non-invasive mechanical ventilation, invasive mechanical ventilation, continuous renal replacement therapy and extracorporeal membrane oxygenation except for prone position ventilation (ATE = –0.022, 95% CI –0.041 to –0.002, p 0.028).

Discussion

IVIG treatment was not associated with significant changes in 28-day mortality in severe COVID-19 patients. The effectiveness of IVIG in treating patients with severe COVID-19 needs to be further investigated through future studies.

Risk Factors and Predictors of Mortality in Streptococcal Necrotizing Soft-tissue Infections: A Multicenter Prospective Study

BACKGROUND

Necrotizing soft-tissue infections (NSTI) are life-threatening conditions often caused by β-hemolytic streptococci, group A Streptococcus (GAS) in particular. Optimal treatment is contentious. The INFECT cohort includes the largest set of prospectively enrolled streptococcal NSTI cases to date.

METHODS

From the INFECT cohort of 409 adults admitted with NSTI to 5 clinical centers in Scandinavia, patients culture-positive for GAS or Streptococcus dysgalactiae (SD) were selected. Risk factors were identified by comparison with a cohort of nonnecrotizing streptococcal cellulitis. The impact of baseline factors and treatment on 90-day mortality was explored using Lasso regression. Whole-genome sequencing of bacterial isolates was used for emm typing and virulence gene profiling.

RESULTS

The 126 GAS NSTI cases and 27 cases caused by SD constituted 31% and 7% of the whole NSTI cohort, respectively. When comparing to nonnecrotizing streptococcal cellulitis, streptococcal NSTI was associated to blunt trauma, absence of preexisting skin lesions, and a lower body mass index. Septic shock was significantly more frequent in GAS (65%) compared to SD (41%) and polymicrobial, nonstreptococcal NSTI (46%). Age, male sex, septic shock, and no administration of intravenous immunoglobulin (IVIG) were among factors associated with 90-day mortality. Predominant emm types were emm1, emm3, and emm28 in GAS and stG62647 in SD.

CONCLUSIONS

Streptococcal NSTI was associated with several risk factors, including blunt trauma. Septic shock was more frequent in NSTI caused by GAS than in cases due to SD. Factors associated with mortality in GAS NSTI included age, septic shock, and no administration of IVIG.

Diagnosis and Management of Intraabdominal Infection: Guidelines by the Chinese Society of Surgical Infection and Intensive Care and the Chinese College of Gastrointestinal Fistula Surgeons

The Chinese guidelines for IAI presented here were developed by a panel that included experts from the fields of surgery, critical care, microbiology, infection control, pharmacology, and evidence-based medicine. All questions were structured in population, intervention, comparison, and outcomes format, and evidence profiles were generated. Recommendations were generated following the principles of the Grading of Recommendations Assessment, Development, and Evaluation system or Best Practice Statement (BPS), when applicable. The final guidelines include 45 graded recommendations and 17 BPSs, including the classification of disease severity, diagnosis, source control, antimicrobial therapy, microbiologic evaluation, nutritional therapy, other supportive therapies, diagnosis and management of specific IAIs, and recognition and management of source control failure. Recommendations on fluid resuscitation and organ support therapy could not be formulated and thus were not included. Accordingly, additional high-quality clinical studies should be performed in the future to address the clinicians' concerns.

Cotrimoxazole and clindamycin in skin and soft tissue infections

PURPOSE OF REVIEW

The aim of this study was to present recent microbiological, experimental, clinical and tolerance data for cotrimoxazole and clindamycin in the specific field of skin and soft tissue infections (SSTIs).

RECENT FINDINGS

Staphylococcus aureus and streptococci remain the leading cause of SSTIs. Cotrimoxazole is a good anti-Gram-positive agent with preserved activity against methicillin-susceptible and methicillin-resistant S. aureus (MRSA) and streptococci. Although clindamycin has good methicillin-susceptible S. aureus activity, a growing number of resistant MRSA and streptococci have been reported. Strong experimental data support the antitoxin activity of clindamycin, but clinical observations remain scarce. Several recent randomized trials involving cotrimoxazole and/or clindamycin demonstrate the efficacy and tolerance of both drugs. The oral formulation of both drugs may facilitate the implementation of early switch and early discharge protocols in clinical practice.

SUMMARY

Recent publications demonstrate that cotrimoxazole and clindamycin remain reliable and realistic therapeutic approaches for SSTIs.

A Predictive Model of Antibody Binding in the Presence of IgG-Interacting Bacterial Surface Proteins

Many bacteria can interfere with how antibodies bind to their surfaces. This bacterial antibody targeting makes it challenging to predict the immunological function of bacteria-associated antibodies. The M and M-like proteins of group A streptococci (GAS) exhibit IgGFc-binding regions, which they use to reverse IgG binding orientation depending on the host environment. Unraveling the mechanism behind these binding characteristics may identify conditions under which bound IgG can drive an efficient immune response. Here, we have developed a biophysical model for describing these complex protein-antibody interactions. We show how the model can be used as a tool for studying the binding behavior of various IgG samples to M protein by performing in silico simulations and correlating this data with experimental measurements. Besides its use for mechanistic understanding, this model could potentially be used as a tool to aid in the development of antibody treatments. We illustrate this by simulating how IgG binding to GAS in serum is altered as specified amounts of monoclonal or pooled IgG is added. Phagocytosis experiments link this altered antibody binding to a physiological function and demonstrate that it is possible to predict the effect of an IgG treatment with our model. Our study gives a mechanistic understanding of bacterial antibody targeting and provides a tool for predicting the effect of antibody treatments in the presence of bacteria with IgG-modulating surface proteins.

Early intravenous immunoglobulin therapy for group A β-haemolytic streptococcal meningitis with toxic shock syndrome

A woman in her forties was transferred to a Sydney (Australia)-based tertiary hospital, following presentation to a regional hospital with group A Streptococcus (GAS) otomastoiditis; complicated by meningitis, venous sinus thrombosis, haemorrhagic cerebral infarction and subdural empyema. She rapidly deteriorated with profound cardiovascular collapse. Despite initiation of high dose vasoactive therapy, she remained shocked and developed multiorgan dysfunction syndrome. Early intravenous immunoglobulin therapy (140 g in two doses) was initiated as an adjunct to antimicrobial, surgical and supportive care for refractory streptococcal toxic shock syndrome. Over the course of a twelve-day intensive care unit stay she made good progress with de-escalation of her vasoactive supportive care and reversal of her organ injuries. She was subsequently discharged to ward-based care. At her three-month follow-up appointment she had significantly reduced neurological deficit. Five months following her presentation to hospital she had returned to full-time work.

Effect of early treatment with polyvalent immunoglobulin on acute respiratory distress syndrome associated with SARS-CoV-2 infections (ICAR trial): study protocol for a randomized controlled trial

BACKGROUND

As of mid-June 2020, 7,500,000 people were infected with SARS-CoV-2 worldwide and 420,000 people died, mainly from coronavirus disease 2019 (COVID-19)-related acute respiratory distress syndrome (ARDS). COVID-19-related ARDS is subject to a mortality rate of 50% and prolonged period of mechanical ventilation, with no specific pharmacological treatment currently available (Infection au nouveau Coronavirus (SARS-CoV-2), COVID-19, France et Monde. https://www.santepubliquefrance.fr/dossiers/coronavirus-covid-19 ). Because of its immunomodulatory action, we propose to evaluate the efficacy and safety of intravenous immunoglobulin (IVIG) administration in patients developing COVID-19-related ARDS.

METHODS

The trial is a phase III double-blind, randomized, multicenter, parallel group, concurrent, controlled study in hospitalized participants with COVID-19 requiring mechanical ventilation using a sequential design. Participants in the treatment group will receive infusions of polyvalent immunoglobulin for 4 consecutive days, and the placebo group will receive an equivalent volume of sodium chloride 0.9% for the same duration. The primary outcome is the number of ventilator-free days up to the 28th day. Secondary objectives are to evaluate the effect of IVIG on (1) organ failure according to the Sequential Organ Failure Assessment (SOFA) score at 14 and 28 days, (2) lung injury score at 14 and 28 days, (3) the occurrence of grade 3 or 4 adverse events of IVIG, (4) length of intensive care unit (ICU) stay, (5) length of hospital stay, (6) functional outcomes at day 90 defined by the activities of daily living and instrumental activities of the daily living scales, and (7) 90-day survival. One hundred thirty-eight subjects will be randomized in a 1:1 ratio to IVIG or placebo groups (69 in each group), considering 90% power, alpha level 0.05 (two sides), and 0.67 effect size level.

DISCUSSION

The ICAR trial investigates the effect of IVIG in COVID-19-related ARDS. We expect an increase in the survival rate and a reduction in the duration of mechanical ventilation, which is associated with significant morbidity.

TRIAL REGISTRATION

EudraCT 2020-001570-30. ClinicalTrials.gov NCT04350580 . Registered on 17 April 2020.

Surgical Infection Society 2020 Updated Guidelines on the Management of Complicated Skin and Soft Tissue Infections

Background: The Surgical Infection Society (SIS) Guidelines for the treatment of complicated skin and soft tissue infections (SSTIs) were published in October 2009 in Surgical Infections. The purpose of this project was to provide a succinct update on the earlier guidelines based on an additional decade of data. Methods: We reviewed the previous guidelines eliminating bite wounds and diabetic foot infections including their associated references. Relevant articles on the topic of complicated SSTIs from 2008-2020 were reviewed and graded individually. Comparisons were then made between the old and the new graded recommendations with review of the older references by two authors when there was disparity between the grades. Results: The majority of new studies addressed antimicrobial options and duration of therapy particularly in complicated abscesses. There were fewer updated studies on diagnosis and specific operative interventions. Many of the topics addressed in the original guidelines had no new literature to evaluate. Conclusions: Most recommendations remain unchanged from the original guidelines with the exception of increased support for adjuvant antimicrobial therapy after drainage of complex abscess and increased data for the use of alternative antimicrobial agents.

Adjunctive Immunotherapy With Polyclonal Ig-M Enriched Immunoglobulins for Septic Shock: From Bench to Bedside. The Rationale for a Personalized Treatment Protocol

Septic shock still has a high mortality rate which has not hinted at decreasing in recent years. Unfortunately, randomized trials failed mainly because the septic patient was considered as a homogeneous entity. All this creates a sort of therapeutic impotence in everyday clinical practice in treating patients with septic shock. The need to customize therapy on each patient with sepsis has now become an established necessity. In this scenario, adjuvant therapies can help if interpreted as modulators of the immune system. Indeed, the host's immune response differs from patient to patient based on the virulence of the pathogen, comorbidity, infection site, and prolonged hospitalization. In this review, we summarize the rationale for using immunoglobulins as an adjunctive treatment. Furthermore, we would like to suggest a possible protocol to personalize treatment in the different clinical scenarios of the host's response to serious infectious events.

When All Else Fails: A Rare Case of Postoperative Toxic Shock Syndrome Arising from Surgical Site Infection after Decompressive Neurectomy Successfully Treated with Angiotensin-2

Toxic shock syndrome is a serious complication of Streptococcus pyogenes or Staphylococcus aureus infections associated with very high morbidity and mortality. Postoperative toxic shock syndrome is an extremely rare phenomenon which manifests as fevers, diffuse rash, septic shock, and death. We present the first reported case of toxic shock syndrome associated with a surgical site infection from a decompressive neurectomy for refractory migraines in a 41-year-old female as well as the first use of angiotensin-2 vasopressor therapy to treat persistent septic shock from toxic shock syndrome refractory to conventional therapies.

Clinical Efficacy of Intravenous Immunoglobulins in Management of Toxic Shock Syndrome: An Updated Literature Review

Toxic shock syndrome (TSS) is an uncommon complication of infection caused by streptococci and staphylococci. It is associated with a high mortality rate. When evaluating patients with shock symptoms from skin or soft tissue sources, a high index of suspicion for TSS must be maintained. Prompt diagnosis and integrative management with surgical intervention, antibiotics, hemodynamic stabilization, and adjuvants like intravenous immunoglobulins improve survival.

The Japanese Clinical Practice Guidelines for Management of Sepsis and Septic Shock 2020 (J-SSCG 2020)

The Japanese Clinical Practice Guidelines for Management of Sepsis and Septic Shock 2020 (J-SSCG 2020), a Japanese-specific set of clinical practice guidelines for sepsis and septic shock created as revised from J-SSCG 2016 jointly by the Japanese Society of Intensive Care Medicine and the Japanese Association for Acute Medicine, was first released in September 2020 and published in February 2021. An English-language version of these guidelines was created based on the contents of the original Japanese-language version. The purpose of this guideline is to assist medical staff in making appropriate decisions to improve the prognosis of patients undergoing treatment for sepsis and septic shock. We aimed to provide high-quality guidelines that are easy to use and understand for specialists, general clinicians, and multidisciplinary medical professionals. J-SSCG 2016 took up new subjects that were not present in SSCG 2016 (e.g., ICU-acquired weakness [ICU-AW], post-intensive care syndrome [PICS], and body temperature management). The J-SSCG 2020 covered a total of 22 areas with four additional new areas (patient- and family-centered care, sepsis treatment system, neuro-intensive treatment, and stress ulcers). A total of 118 important clinical issues (clinical questions, CQs) were extracted regardless of the presence or absence of evidence. These CQs also include those that have been given particular focus within Japan. This is a large-scale guideline covering multiple fields; thus, in addition to the 25 committee members, we had the participation and support of a total of 226 members who are professionals (physicians, nurses, physiotherapists, clinical engineers, and pharmacists) and medical workers with a history of sepsis or critical illness. The GRADE method was adopted for making recommendations, and the modified Delphi method was used to determine recommendations by voting from all committee members. As a result, 79 GRADE-based recommendations, 5 Good Practice Statements (GPS), 18 expert consensuses, 27 answers to background questions (BQs), and summaries of definitions and diagnosis of sepsis were created as responses to 118 CQs. We also incorporated visual information for each CQ according to the time course of treatment, and we will also distribute this as an app. The J-SSCG 2020 is expected to be widely used as a useful bedside guideline in the field of sepsis treatment both in Japan and overseas involving multiple disciplines.

Intravenous Immunoglobulin for Overwhelming Postsplenectomy Infection

Overwhelming postsplenectomy infection (OPSI) is a life-threatening condition causing fulminant bacteremia in asplenic patients. Intravenous immunoglobulin (IVIG) therapy is theoretically effective for OPSI. Herein, we present a case of OPSI treated successfully with IVIG, along with results of a literature review. An asplenic 70-year-old male with acute ischemic stroke presented with rapid and fulminant septic shock from pneumococcus pneumonia and bacteremia. Resuscitation and antibiotics including IVIG therapy were instituted. The patient survived with favorable outcomes. We analyzed all case reports or case series of OPSI from 1971 through 2017. Cases with IVIG treatment showed a significantly higher survival rate than those without IVIG, even with multivariable regression analysis, suggesting IVIG as an independent predictive factor for survival. It suggests that IVIG is effective for OPSI and that it can be regarded as an adjunctive treatment option for OPSI.

Necrotizing Soft Tissue Infections

Necrotizing soft tissue infections occur after traumatic injuries, minor skin lesions, nonpenetrating injuries, natural childbirth, and in postsurgical and immunocompromised patients. Infections can be severe, rapidly progressive, and life threatening. Survivors often endure multiple surgeries and prolonged hospitalization and rehabilitation. Despite subtle nuances that may distinguish one entity from another, clinical approaches to diagnosis and treatment are highly similar. This review describes the clinical and laboratory features of necrotizing soft tissue infections and addresses recommended diagnostic and treatment modalities. It discusses the impact of delays in surgical debridement, antibiotic use, and resuscitation on mortality, and summarizes key pathogenic mechanisms.

[Necrotizing fasciitis in the head and neck region-three case reports and a review of the literature]

Necrotizing fasciitis (NF) is a life-threatening, usually bacterial, soft tissue infection that rarely affects the head and neck region. Rapid progression and systemic illness are typical for the disease and complicate diagnosis. Immediate surgical and antimicrobial therapy is required. Three cases of cervicofacial NF are presented in this case report. All patients showed a rapidly progressing, painful swelling and redness in the cervicofacial region. After diagnosing NF based on clinical symptoms, laboratory parameters, and CT, the patients were treated with systemic antibiotics and multiple extensive debridements. Two of the three patients died within 48 h from systemic illness with septic organ failure; one patient was discharged after intensive care treatment and reconstruction of the tissue defects caused by debridement. NF is a fast-developing soft tissue infection associated with high mortality and morbidity, and is often recognized too late. Diagnosis is based on clinical signs such as progressive diffuse swelling, pain, erythema, and early systemic illness. Laboratory parameters (Laboratory Risk Indicator for Necrotizing Fasciitis [LRINEC] score) and imaging via CT or MRT are helpful. CT/MRT images can show soft tissue swelling with pathognomonic gas formation. Immediate surgical debridement and antimicrobial therapy are critical for survival. Intravenously administered immunoglobulins and hyperbaric pressure therapy should only be used as supplementary treatments.