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Streptococcus pyogenes can cause a variety of diseases in immunocompetent individuals, from pharyngotonsillitis to life-threatening invasive diseases, such as streptococcal toxic shock syndrome, and rapidly progressing deep-tissue infections, such as necrotizing fasciitis. Necrotizing fasciitis is often seen in combination with streptococcal toxic shock syndrome, which further increases morbidity and mortality.We review here the hostpathogen interactions in the tissue milieu and discuss the use of intravenous immunoglobulin as potential adjunctive therapy in these life-threatening infections. [ABSTRACT FROM AUTHOR]

Host-pathogen interactions were studied in tissue biopsy samples from patients with severe invasive group A streptococcus (GAS) infections. Skin, subcutaneous tissue, and fascia biopsy samples were divided into clinical grade 1 (no evidence of inflammation [n = 7]) or clinical grade 2 (inflamed tissue—erythema and edema including cellulitis, fasciitis, and necrotizing fasciitis [n = 24]). In situ imaging demonstrated significantly higher bacterial load in biopsy samples of higher clinical grade (P<.05), and the bacterial load correlated with the in vivo expression of the superantigen streptococcal pyrogenic exotoxin F (P<.02). Increased expression of the interleukin-1 cytokines and significantly higher expression of tumor necrosis factor-β, interferon-γ, and the homing receptors CC chemokine receptor 5, CD44, and cutaneous lymphocyte-associated antigen (P<.002–.05) were observed in biopsy samples of higher clinical grade. Thus, the cytokine profile at the local site of infection mimics that of a typical superantigen cytokine response. The findings of this study demonstrate a critical role for superantigens and Th1 cytokines in GAS tissue infections. [ABSTRACT FROM AUTHOR]

Circulating antieosinophil antibodies (AEOSA) have been associated with various autoimmune conditions affecting the liver, kidneys, lungs, and joints but are not part of routine clinical diagnostics. While analyzing human sera for antineutrophil cytoplasmic antibodies (ANCA) by indirect immunofluorescence (IIF) on granulocytes, 0.8% of analyzed samples were found to be reactive with eosinophils. Our aim was to determine the diagnostic relevance and antigenic specificity of AEOSA. AEOSA were seen either in combination with an myeloperoxidase (MPO)-positive p-ANCA (44%; AEOSA+/ANCA+) or on their own (56%; AEOSA+/ANCA−). AEOSA/ANCA positivity was seen in patients with thyroid disease (44%) or vasculitis (31%), while AEOSA+/ANCA− pattern was more common in patients with autoimmune disorders of the gastrointestinal tract and/or liver. Eosinophil peroxidase (EPX) was the main target recognized in 66% of the AEOSA+ sera by enzyme-linked immunosorbent assay (ELISA). Eosinophil cationic protein (ECP) and eosinophil-derived neurotoxin (EDN) were also identified as target antigens but less frequently and only in combination with EPX. In conclusion, we confirmed that EPX is a major target of AEOSA, illustrating the high antigenic potential of EPX. Our results also demonstrate the presence of concomitant AEOSA/ANCA positivity in a defined patient group. Further research should aim to elucidate the association of AEOSA with autoimmunity. [ABSTRACT FROM AUTHOR]

Background: Group A streptococcal severe soft tissue infections, such as necrotizing fasciitis, are rapidly progressive infections associated with high mortality. Group A streptococcus is typically considered an extracellular pathogen, but has been shown to reside intracellularly in host cells.Methods and Findings: We characterized in vivo interactions between group A streptococci (GAS) and cells involved in innate immune responses, using human biopsies (n = 70) collected from 17 patients with soft tissue infections. Immunostaining and in situ image analysis revealed high amounts of bacteria in the biopsies, even in those collected after prolonged antibiotic therapy. Viability of the streptococci was assessed by use of a bacterial viability stain, which demonstrated viable bacteria in 74% of the biopsies. GAS were present both extracellularly and intracellularly within phagocytic cells, primarily within macrophages. Intracellular GAS were predominantly noted in biopsies from newly involved tissue characterized by lower inflammation and bacterial load, whereas purely extracellular GAS or a combination of intra- and extracellular GAS dominated in severely inflamed tissue. The latter tissue was also associated with a significantly increased amount of the cysteine protease streptococcal pyrogenic exotoxin SpeB. In vitro studies confirmed that macrophages serve as reservoirs for viable GAS, and infection with a speB-deletion mutant produced significantly lower frequencies of cells with viable GAS following infection as compared to the wild-type bacteria.Conclusions: This is the first study to demonstrate that GAS survive intracellularly in macrophages during acute invasive infections. This intracellular presence may have evolved as a mechanism to avoid antibiotic eradication, which may explain our finding that high bacterial load is present even in tissue collected after prolonged intravenous antibiotic therapy. This new insight into the pathogenesis of streptococcal soft tissue infections highlights a need for alternative therapeutic strategies. [ABSTRACT FROM AUTHOR]

The skeleton is the preferred site for prostate cancer (PC) metastasis leading to incurable castration-resistant disease. The increased expression of genes encoding steroidogenic enzymes found in bone metastatic tissue from patients suggests that up-regulated steroidogenesis might contribute to tumor growth at the metastatic site. Because of the overall sclerotic phenotype, we hypothesize that osteoblasts regulate the intratumoral steroidogenesis of castration resistant prostate cancer (CRPC) in bone. We here show that osteoblasts alter the steroidogenic transcription program in CRPC cells, closely mimicking the gene expression pattern described in CRPC. Osteoblast-stimulated LNCaP-19 cells displayed an increased expression of genes encoding for steroidogenic enzymes ( CYP11A1 , HSD3B1 , and AKR1C3 ), estrogen signaling-related genes ( CYP19A1 , and ESR2 ), and genes for DHT-inactivating enzymes ( UGT2B7 , UGT2B15 , and UGT2B17 ). The observed osteoblast-induced effect was exclusive to osteogenic CRPC cells (LNCaP-19) in contrast to osteolytic PC-3 and androgen-dependent LNCaP cells. The altered steroid enzymatic pattern was specific for the intratibial tumors and verified by immunohistochemistry in tissue specimens from LNCaP-19 xenograft tumors. Additionally, the overall steroidogenic effect was reflected by corresponding levels of progesterone and testosterone in serum from castrated mice with intratibial xenografts. A bi-directional interplay was demonstrated since both proliferation and Esr2 expression of osteoblasts were induced by CRPC cells in steroid-depleted conditions. Together, our results demonstrate that osteoblasts are important mediators of the intratumoral steroidogenesis of CRPC and for castration-resistant growth in bone. Targeting osteoblasts may therefore be important in the development of new therapeutic approaches. [ABSTRACT FROM AUTHOR]

Bacterial skin infections, such as erysipelas or cellulitis, are characterized by fever and a painful erythematous rash. Despite the high prevalence of these infections, little is known about the underlying pathogenic mechanisms. This is partly due to the fact that a bacterial diagnosis is often difficult to attain. To gain insight into the pathogenesis of erysipelas, we investigated the samples obtained from infected and noninfected areas of skin from 12 patients with erysipelas. Bacterial cultures, detection of specific streptococcal antibodies in convalescent sera, and immunohistochemical analyses of biopsies indicated group A streptococcal etiology in 11 of the 12 patients. Also, electron micrographs of erythematous skin confirmed the presence of group A streptococcal cells and showed a limited solubilization of the surface-attached M protein. Degradation of high-molecular-weight kininogen and upregulation of the bradykinin-1 receptor in inflamed tissues indicated activation of the contact system in 11 patients. Analyses of release of the vasoactive heparin-binding protein (HBP) showed increased levels in the infected as compared with the noninfected areas. The results suggest that group A streptococci induce contact activation and HBP release during skin infection, which likely contribute to the symptoms seen in erysipelas: fever, pain, erythema, and edema. [ABSTRACT FROM AUTHOR]

The amount and time course of SpeA release from group A streptococci (GAS) was studied at different starting inoculae after exposure to different doses of penicillin, clindamycin or a combination of the 2. The release was related to the bacterial concentration and killing rate. A clinical GAS strain was exposed to benzylpenicillin, 2 and 1000×MIC, clindamycin, 2 and 32×MIC, or combinations of the 2. Samples for viable counts and SpeA analyses were drawn before and after the addition of antibiotics and at 3, 6 and 24h. The SpeA release was higher at low than at high concentrations of penicillin and the combination (both, p<0.05). The addition of clindamycin to penicillin reduced SpeA production at both concentrations (p<0.01). Most SpeA was released before 3 h, and for penicillin and the combination, the amount correlated to the number of killed bacteria during this period (r=0.50; p<0.05). A positive correlation was found between the inoculum size and the SpeA concentration at time zero (r=0.54; p<0.05). The SpeA concentration was dependent on the initial number of bacteria, the class of antibiotic, the dose of penicillin and the killing rate. [ABSTRACT FROM AUTHOR]

Background: Postoperative inflammation is a common consequence of surgery and the ensuing stress response. Local anesthetics have anti-inflammatory properties. The primary aim of this study was to evaluate if LA administrated intraperitoneally perioperatively might inhibit expression of inflammatory cytokines.Methods: This was a, randomized, double blind, placebo-controlled study (ClinicalTrial.gov reg no: NCT02256228) in patients undergoing surgery for ovarian cancer. Patients were randomized to receive: intraperitoneal ropivacaine (Group IPLA) or saline (Group P) perioperatively. Except for study drug, patients were treated similarly. At the end of surgery, a multi-port catheter was inserted intraperitoneally, and ropivacaine 2 mg/mL or 0.9% saline, 10 mL was injected intermittently every other hour during 72 hours postoperatively. Systemic expression of cytokines and plasma ropivacaine were determined before and 6, 24, and 48 hours after surgery. Stress response was measured by serum glucose, cortisol, and insulin.Results: Forty patients were recruited, 20 in each group. There was no statistical significant difference in systemic cytokine between the groups at any time point. Serum cortisol was significantly lower in the IPLA group at 6 hours, median 103 nmol/L (IQR 53-250) compared to placebo, median 440 nmol/L (IQR 115-885), P = 0.023. Serum glucose and insulin were similar between the groups. Total and free serum concentrations of ropivacaine were well below toxic concentrations.Conclusion: In this small study, perioperative intraperitoneal ropivacaine did not reduce the systemic inflammatory response associated with major abdominal surgery. Total and free ropivacaine concentrations were below known toxic concentrations in humans. [ABSTRACT FROM AUTHOR]

Intravenous polyspecific immunoglobulin G (IVIG) has been reported to be efficacious as adjunctive therapy in patients with toxic shock syndrome caused by group A streptococci (GAS). GAS is also an important cause of necrotizing fasciitis, for which an early and extensive surgical intervention is currently advocated. Here we report on the use of an aggressive medical regimen including high-dose IVIG together with a conservative surgical approach in severe GAS soft tissue infection. We describe 7 patients with severe soft tissue infection caused by GAS, who all were treated with effective antimicrobials and high-dose IVIG. Surgery was either not performed or only limited exploration was carried out. Six of the patients had toxic shock syndrome. All patients survived. Immunostaining of tissue biopsies from 2 of the patients revealed high levels of GAS, superantigen and pro-inflammatory cytokines initially, which were dramatically reduced in a repeat biopsy of the initial operative site collected from 1 of the patients 66 h post-IVIG administration. The study suggests that the use of a medical regimen including IVIG in patients with severe GAS soft tissue infections may allow an initial non-operative or minimally invasive approach, which can limit the need to perform immediate wide debridements and amputations in unstable patients. [ABSTRACT FROM AUTHOR]