Analysis of complications and revisions after spine surgery in 270 multiple myeloma patients with spinal involvement.

BACKGROUND CONTEXT: Patients with multiple myeloma (MM) are at increased risk of infections and suffer from poor bone quality due to their disseminated malignant bone disease. Therefore, postoperative complications may occur following surgical treatment of MM lesions. PURPOSE: In this study, we aimed to determine the incidence of postoperative complications and retreatments after spinal surgery in MM patients. Additionally, we sought to identify risk factors associated with complications and retreatments. STUDY DESIGN: Retrospective cohort study. PATIENT SAMPLE: In total, 270 patients with MM who received surgical treatment for spinal involvement between 2008 and 2021 were included. OUTCOME MEASURES: The incidence of perioperative complications within 6 weeks and reoperations within 2.5 years and individual odds ratios for factors associated with these complications and reoperations. METHODS: Data were collected through manual chart review. Hosmer and Lemeshow's purposeful regression method was used to identify risk factors for complications and reoperations. RESULTS: The median age of our cohort was 65 years (SD = 10.8), and 58% were male (n = 57). Intraoperative complications were present in 24 patients (8.9%). The overall 6-week complication rate after surgery was 35% (n = 95). The following variables were independently associated with 6-week complications: higher Genant grading of a present vertebral fracture (OR 1.41; 95% CI 1.04-1.95; p = .031), receiving intramuscular or intravenous steroids within a week prior to surgery (OR 3.97; 95% CI 1.79-9.06; p = .001), decompression surgery without fusion (OR 6.53; 95% CI 1.30-36.86; p = .026), higher creatinine levels (OR 2.18; 95% CI 1.19-5.60; p = .014), and lower calcium levels (OR 0.58; 95% CI 0.37-0.88; p = .013). A secondary surgery was indicated for 53 patients (20%), of which 13 (4.8%) took place within two weeks after the initial surgery. We additionally discovered factors associated with retreatments, which are elucidated within the manuscript. CONCLUSION: The goal of surgical treatment for MM bone disease is to enhance patient quality of life and reduce symptom burden. However, postoperative complication rates remain relatively high after spine surgery in patients with MM, likely attributable to both inherent characteristics of the disease and patient comorbidities. The risk for complications and secondary surgeries should be explored and a multidisciplinary approach is crucial.

Neurologic Outcomes After Radiation Therapy for Severe Spinal Cord Compression in Multiple Myeloma: A Study of 162 Patients.

BACKGROUND: Bone destruction is the most frequent disease-defining clinical feature of multiple myeloma (MM), resulting in skeletal-related events such as back pain, pathological fractures, or neurologic compromise including epidural spinal cord compression (ESCC). Up to 24% of patients with MM will be affected by ESCC. Radiation therapy has been proven to be highly effective in pain relief in patients with MM. However, a critical knowledge gap remains with regard to neurologic outcomes in patients with high-grade ESCC treated with radiation. METHODS: We retrospectively included 162 patients with MM and high-grade ESCC (grade 2 or 3) who underwent radiation therapy of the spine between January 2010 and July 2021. The primary outcome was the American Spinal Injury Association (ASIA) score after 12 to 24 months, or the last known ASIA score if the patient had had a repeat treatment or died. Multivariable logistic regression was used to assess factors associated with poor neurologic outcomes after radiation, defined as neurologic deterioration or lack of improvement. RESULTS: After radiation therapy, 34 patients (21%) had no improvement in their impaired neurologic function and 27 (17%) deteriorated neurologically. Thirty-six patients (22%) underwent either surgery or repeat irradiation after the initial radiation therapy. There were 100 patients who were neurologically intact at baseline (ASIA score of E), of whom 16 (16%) had neurologic deterioration. Four variables were independently associated with poor neurologic outcomes: baseline ASIA (odds ratio [OR] = 6.50; 95% confidence interval [CI] = 2.70 to 17.38; p < 0.001), Eastern Cooperative Oncology Group (ECOG) performance status (OR = 6.19; 95% CI = 1.49 to 29.49; p = 0.015), number of levels affected by ESCC (OR = 4.02; 95% CI = 1.19 to 14.18; p = 0.026), and receiving steroids prior to radiation (OR = 4.42; 95% CI = 1.41 to 16.10; p = 0.015). CONCLUSIONS: Our study showed that 38% of patients deteriorated or did not improve neurologically after radiation therapy for high-grade ESCC. The results highlight the need for multidisciplinary input and efforts in the treatment of high-grade ESCC in patients with MM. Future studies will help to improve patient selection for specific and standardized treatments and to clearly delineate which patients are likely to benefit from radiation therapy. LEVEL OF EVIDENCE: Therapeutic Level IV . See Instructions for Authors for a complete description of levels of evidence.

Prospective study for establishing minimal clinically important differences in patients with surgery for lower extremity metastases.

BACKGROUND: The clinical relevance of patient-reported outcomes score changes is often unclear. Especially in patients undergoing surgery due to lower extremity metastases - where surgery is performed in the palliative setting and the goal is to optimize functional mobility, relieve pain and improve overall quality of life. This study assessed the minimal clinically important difference (MCID) of Patient-Reported Outcomes Measurement Information System (PROMIS) Pain Interference, Cancer-specific Physical Function, and Global (Physical and Mental Health) in patients treated surgically for impending or completed pathologic fractures. METHODS: Patients undergoing surgery for osseous metastasis of the lower extremity because of an impending or completed pathologic fracture were consecutively enrolled in this tertiary center study. Patients completed the three PROMIS questionnaires preoperatively (n = 56) and at postoperative follow-up (n = 33) assessment one to three months later. Of the 23 patients that did not complete the postoperative survey, 5 patients died within 1-3 months and 18 patients were alive at 3-months but did not respond or show up at their postoperative consult. Thirty-one patients (94%) of the 33 included patients reported at least minimal improvement and two patients (6.1%) no change 1-3 months after the surgery based on an anchor-based approach. RESULTS: The PROMIS MCIDs (95% confidence interval) for Pain Interference was 7.5 (3.4-12), Physical Function 4.1 (0.6-7.6), Global Physical Health 4.2 (2.0-6.6), and Global Mental Health 0.8 (-4.5-2.9). CONCLUSION: This prospective study successfully defined a MCID for PROMIS Pain Interference of 7.5 (3.4-12), PROMIS Physical Function of 4.1 (0.6-7.6), and Global Physical Health of 4.2 (2.0-6.6) in patients with (impending) pathological fractures due to osseous metastases in the lower extremity; no MCID could be established for PROMIS Global Mental Health. Defining a narrower MCID value for each subpopulation requires a large, prospective, multicenter study. Nevertheless, the provided MCID values allow guidance to clinicians to evaluate the impact of surgical treatment on a patient's QoL. LEVEL OF EVIDENCE: Level II Diagnostic study.

Adipose tissue density on CT as a prognostic factor in patients with cancer: a systematic review.

BACKGROUND: Predicting oncologic outcomes is essential for optimizing the treatment for patients with cancer. This review examines the feasibility of using Computed Tomography (CT) images of fat density as a prognostic factor in patients with cancer. METHODS: A systematic literature search was performed in PubMed, Embase and Cochrane up to March 2020. All studies that mentioned using subcutaneous or visceral adipose tissue (SAT and VAT, respectively) CT characteristics as a prognostic factor for patients with cancer were included. The primary endpoints were any disease-related outcomes in patients with cancer. RESULTS: After screening 1043 studies, ten studies reporting a total of 23 - ten for SAT and thirteen for VAT - comparisons on survival, tumor recurrence and postsurgical infection were included. All ten studies included different types of malignancy: six localized, two metastatic disease, and two both. Five different anatomic landmarks were used to uniformly measure fat density on CT: lumbar (L)4 (n = 4), L3 (n = 2), L4-L5 intervertebral space (n = 2), L5-S1 intervertebral space (n = 1), and the abdomen (n = 1). Overall, six of ten SAT comparisons (60%) and six of thirteen VAT comparisons (46%) reported a significant (p < .05) association of increased SAT or VAT density with an adverse outcome. All remaining nonsignificant comparisons, except one, deviated in the same direction of being predictive for adverse outcomes but failed to reach significance. The median hazard ratio (HR) for the nine SAT and thirteen VAT associations where HRs were given were 1.45 (95% confidence interval [CI] 1.01-1.97) and 1.90 (95% CI 1.12-2.74), respectively. The binomial sign test and Fisher's method both reported a significant association between both SAT and VAT and adverse outcomes. CONCLUSION: This review may support the feasibility of using SAT or VAT on CT as a prognostic tool for patients with cancer in predicting adverse outcomes such as survival and tumor recurrence. Future research should standardize radiologic protocol in prospective homogeneous series of patients on each cancer diagnosis group in order to establish accurate parameters to help physicians use CT scan defined characteristics in clinical practice.

Management of metastatic humeral fractures: Variations according to orthopedic subspecialty, tumor characteristics.

HYPOTHESIS: This study assessed, if there was a difference in surgical decision making for metastatic humeral lesions based on; orthopaedic subspecialty, tumor characteristics. STUDY TYPE: Cross sectional survey study. MATERIALS AND METHODS: Twenty-four case scenarios were created by combining: tumor type, life expectancy, fracture type, and anatomical location. Participants were asked for every case: what treatment would you recommend? Participants were 78 (48%) orthopaedic oncologists and 83 (52%) orthopaedic surgeons that were not regularly involved in the treatment of bone tumors. RESULTS: There was a difference between orthopaedic oncologists and other subspecialty surgeons in recommendation for specific treatments: intramedullary nailing was less often recommended by orthopaedic oncologists (53%, 95%CI: 47-59) compared to other surgeons (62%, 95%CI: 57-67) (p=0.023); while endoprosthetic reconstruction (orthopaedic oncologists: 8.8% [95%CI: 6.6-11], other surgeons: 3.6%[95%CI: 2.3-4.8], p<0.001) and plate-screw fixation (orthopaedic oncologists: 19%[95%CI: 14-25], other surgeons: 9.5%[95%CI: 5.9-13], p=0.003) were more often recommended by orthopaedic oncologists. There was no difference in recommendation for nonoperative management. There were differences in recommendation for specific treatments based on tumor type, life expectancy, and anatomical location, but not fracture type. DISCUSSION: Subspecialty training and patient and tumor characteristics influence the decision for operative management and the decision for a specific implant in metastatic humeral fractures. LEVEL OF EVIDENCE: Level 3.

Quality of life after resection of a chordoma of the mobile spine.

AIMS: The aim of the study was to compare measures of the quality of life (QOL) after resection of a chordoma of the mobile spine with the national averages in the United States and to assess which factors influenced the QOL, symptoms of anxiety and depression, and coping with pain post-operatively in these patients. PATIENTS AND METHODS: A total of 48 consecutive patients who underwent resection of a primary or recurrent chordoma of the mobile spine between 2000 and 2015 were included. A total of 34 patients completed a survey at least 12 months post-operatively. The primary outcome was the EuroQol-5 Dimensions (EQ-5D-3L) questionnaire. Secondary outcomes were the Patient-Reported Outcome Measurement Information System (PROMIS) anxiety, depression and pain interference questionnaires. Data which were recorded included the indication for surgery, the region of the tumour, the number of levels resected, the status of the surgical margins, re-operations, complications, neurological deficit, length of stay in hospital and rate of re-admission. RESULTS: The median EQ-5D-3L score was 0.71 (interquartile range (IQR) 0.44 to 0.79) which is worse than the national average in the United States of 0.85 (p < 0.001). Anxiety (median: 55 (IQR 49 to 61), p = 0.031) and pain (median: 61 (IQR 56 to 68), p < 0.001) were also worse than the national average in the United States (50), while depression was not (median: 52 (IQR 38 to 57), p = 0.513). Patients who underwent a primary resection had better QOL and less anxiety, depression and pain compared with those who underwent resection for recurrent or residual disease. The one- and five-year probabilities were 0.96 and 0.74 for survival, 0.07 and 0.25 for tumour recurrence, and 0.02 and 0.16 for developing distant metastasis. A total of 25 local complications occurred in 20 patients (42%), and there were 50 systemic and other complications in 25 patients (52%) within 90 days. CONCLUSION: These patient reported outcomes and oncological and surgical outcomes can be used when counselling patients and to aid decision-making when planning surgery. Cite this article: Bone Joint J 2017;99-B:979-86.

Functional and oncological outcome after surgical resection of the scapula and clavicle for primary chondrosarcoma.

PURPOSE: The scapula is a relatively common site for chondrosarcoma to develop in contrary to the clavicle, which is rarely affected by these tumors. The aim of this study is to determine the functional and oncological outcome for patients treated operatively for scapular or clavicular chondrosarcoma. METHODS: In this single-center retrospective study, we included a sample of 20 patients that received the diagnosis of a primary chondrosarcoma of the scapula or clavicle. Of the surviving patients, the functional function was assessed using the DASH and the PROMIS Physical Function-Upper Extremity. Patients were longitudinally tracked for their oncological outcome. RESULTS: All patients were followed for at least 2 years or until death. The mean age of the cohort was 47 years. Eighteen patients suffered from a chondrosarcoma of the scapula, and in 2 patients, the tumor was located in the clavicle. Metastasis, local recurrence and a higher tumor grade were all associated with a decreased overall survival. For the patients with a chondrosarcoma of the scapula, the average DASH score was 16 ± 16 and the mean PROMIS Physical Function-Upper Extremity score was 48 ± 10. Patients with both an intact rotator cuff and glenoid had a better physical function. CONCLUSIONS: Upper extremity function after (partial) scapulectomy varied depending on whether the glenoid was spared and whether a functioning shoulder abductor remained. When the resection spared these structures, then excellent functional outcomes were reported. Oncologic outcomes depended upon the grade of the tumor and whether local recurrence and metastases occurred.

What Factors are Associated With Quality Of Life, Pain Interference, Anxiety, and Depression in Patients With Metastatic Bone Disease?

BACKGROUND: It would be helpful for the decision-making process of patients with metastatic bone disease to understand which patients are at risk for worse quality of life (QOL), pain, anxiety, and depression. Normative data, and where these stand compared with general population scores, can be useful to compare and interpret results of similar patients or patient groups, but to our knowledge, there are no such robust data. QUESTIONS/PURPOSES: We wished (1) to assess what factors are independently associated with QOL, pain interference, anxiety, and depression in patients with metastatic bone disease, and (2) to compare these outcomes with general US population values. METHODS: Between November 2011 and February 2015, 859 patients with metastatic bone disease presented to our orthopaedic oncology clinic; 202 (24%) were included as they completed the EuroQOL-5 Dimension (EQ-5DTM), PROMIS® Pain Interference, PROMIS® Anxiety, and PROMIS® Depression questionnaires as part of a quality improvement program. We did not record reasons for not responding and found no differences between survey respondents and nonrespondents in terms of age (63 versus 64 years; p = 0.916), gender (51% men versus 47% men; p = 0.228), and race (91% white versus 88% white; p = 0.306), but survey responders were more likely to be married or living with a partner (72%, versus 62%; p = 0.001). We assessed risk factors for QOL, pain interference, anxiety, and depression using multivariable linear regression analysis. We used the one-sample signed rank test to assess whether scores differed from US population averages drawn from earlier large epidemiologic studies. RESULTS: Younger age (ß regression coefficient [ß], < 0.01; 95% CI, 0.00-0.01; p = 0.041), smoking (ß, -0.12; 95% CI, -0.22 to -0.01; p = 0.026), pathologic fracture (ß, -0.10; 95% CI, -0.18 to -0.02; p = 0.012), and being unemployed (ß, -0.09; 95% CI, -0.17 to -0.02; p = 0.017) were associated with worse QOL. Current smoking status was associated with more pain interference (ß, 6.0; 95% CI, 1.6-11; p = 0.008). Poor-prognosis cancers (ß, 3.8; 95% CI, 0.37-7.2; p = 0.030), and pathologic fracture (ß, 6.3; 95% CI, 2.5-7.2; p = 0.001) were associated with more anxiety. Being single (ß, 5.9; 95% CI, 0.83-11; p = 0.023), and pathologic fracture (ß, 4.4; 95% CI, 0.8-8.0; p = 0.017) were associated with depression. QOL scores (0.68 versus 0.85; p < 0.001), pain interference scores (65 versus 50; p < 0.001), and anxiety scores (53 versus 50; p = 0.011) were worse for patients with bone metastases compared with general US population values, whereas depression scores were comparable (48 versus 50; p = 0.171). CONCLUSIONS: Impending pathologic fractures should be treated promptly to prevent deterioration in QOL, anxiety, and depression. Our normative data can be used to compare and interpret results of similar patients or patient groups. Future studies could focus on specific cancers metastasizing to the bone, to further understand which patients are at risk for worse patient-reported outcomes. LEVEL OF EVIDENCE: Level III, prognostic study.

CSPG4 in cancer: multiple roles.

Chondroitin sulfate proteoglycan 4 (CSPG4), also known as High Molecular Weight-Melanoma Associated Antigen, is a cell surface proteoglycan which has been recently shown to be expressed not only by melanoma cells, but also by various types of human carcinoma and sarcoma. Furthermore, at least in squamous cell carcinoma of head and neck and in basal breast carcinoma, CSPG4 is expressed by cancer stem cells. CSPG4 plays an important role in tumor cell growth and survival. These CSPG4-associated functional properties of tumor cells are inhibited by CSPG4-specific monoclonal antibodies (mAb) in vitro. Moreover, CSPG4-specific mAb can also inhibit tumor growth and metastasis in vivo. The anti-tumor effects of CSPG4-specific mAb are likely to reflect the blocking of important migratory, mitogenic and survival signaling pathways in tumor cells. These results indicate that CSPG4 is a promising new target to implement mAb-based immunotherapy of various types of cancer.

Wide en bloc extra-articular excision of the elbow for sarcoma with complex reconstruction.

We describe a consecutive series of five patients with bone or soft-tissue sarcomas of the elbow and intra-articular extension treated by complex soft tissue, allograft bone and prosthetic joint replacement after wide extra-articular en bloc excision. All had a pedicled myocutaneous latissimus dorsi rotation flap for soft-tissue cover and reconstruction of the triceps. Wide negative surgical margins were obtained in all five patients. No local wound complications or infections were seen. There were no local recurrences at a mean follow-up of 60 months (20 to 105). The functional results were excellent in four patients and good in one. Longer term follow-up is necessary to confirm the durability of the elbow reconstruction.

Dietary glycine prevents peptidoglycan polysaccharide-induced reactive arthritis in the rat: role for glycine-gated chloride channel.

Peptidoglycan polysaccharide (PG-PS) is a primary structural component of bacterial cell walls and causes rheumatoid-like arthritis in rats. Recently, glycine has been shown to be a potential immunomodulator; therefore, the purpose of this study was to determine if glycine would be protective in a PG-PS model of arthritis in vivo. In rats injected with PG-PS intra-articularly, ankle swelling increased 21% in 24 to 48 h and recovered in about 2 weeks. Three days prior to reactivation with PG-PS given intravenously (i.v.), rats were divided into two groups and fed a glycine-containing or nitrogen-balanced control diet. After i.v. PG-PS treatment joint swelling increased 2.1 +/- 0.3 mm in controls but only 1.0 +/- 0.2 mm in rats fed glycine. Infiltration of inflammatory cells, edema, and synovial hyperplasia in the joint were significantly attenuated by dietary glycine. Tumor necrosis factor alpha (TNF-alpha) mRNA was detected in ankle homogenates from rats fed the control diet but not in ankles from rats fed glycine. Moreover, intracellular calcium was increased significantly in splenic macrophages treated with PG-PS; however, glycine blunted the increase about 50%. The inhibitory effect of glycine was reversed by low concentrations of strychnine or chloride-free buffer, and it increased radiolabeled chloride influx nearly fourfold, an effect also inhibited by strychnine. In isolated splenic macrophages, glycine blunted translocation of the p65 subunit of NF-kappaB into the nucleus, superoxide generation, and TNF-alpha production caused by PG-PS. Further, mRNA for the beta subunit of the glycine receptor was detected in splenic macrophages. This work supports the hypothesis that glycine prevents reactive arthritis by blunting cytokine release from macrophages by increasing chloride influx via a glycine-gated chloride channel.

Selective kallikrein-kinin system activation in inbred rats differentially susceptible to granulomatous enterocolitis.

BACKGROUND & AIMS: Crohn's disease is characterized by unrestrained inflammation with a genetic component. Genetic susceptibility and activation of the kalli-krein-kinin (contact) system were investigated in experimental enterocolitis and extraintestinal inflammation induced by bacterial polymers. METHODS: Kinetics of inflammation in inbred Lewis and Buffalo rats injected subserosally with peptidoglycan-polysaccharide polymers were correlated with in vivo and in vitro activation of the contact system. RESULTS: Lewis rats had a biphasic course of enterocolitis. Acute inflammation peaked 1 day after injection, gradually decreasing until day 14 when intestinal inflammation spontaneously reactivated and persisted for 16 weeks, accompanied by arthritis, granulomatous hepatitis, anemia, and leukocytosis. Self-limited acute enterocolitis in Buffalo rats resolved by 24 days without extraintestinal involvement. Consumption of the precursor proteins prekalli-krein and high-molecular-weight kininogen indicated activation of the plasma contact system in Lewis rats and closely correlated with chronic intestinal inflammation. Contact system activation did not occur in Buffalo rats, even during acute inflammation. In vitro studies showed a decreased rate of kininogen cleavage in Buffalo plasma. CONCLUSIONS: Selective in vivo and in vitro activation of the contact system in susceptible Lewis rats suggests that this pathway is one determinant of genetic susceptibility to granulomatous enterocolitis and systemic complications.

Suppression of experimental arthritis by gene transfer of interleukin 1 receptor antagonist cDNA.

Restoration of the impaired balance between pro- and antiinflammatory cytokines should provide effective treatment of rheumatoid arthritis. Gene therapy has been proposed as an approach for delivery of therapeutic proteins to arthritic joints. Here, we examined the efficacy of antiinflammatory gene therapy in bacterial cell wall-induced arthritis in rats. Human secreted interleukin 1 receptor antagonist (sIL-1ra) was expressed in joints of rats with recurrent bacterial cell wall-induced arthritis by using ex vivo gene transfer. To achieve this, primary synoviocytes were transduced in culture with a retroviral vector carrying the sIL-1ra cDNA. Transduced cells were engrafted in ankle joints of animals prior to reactivation of arthritis. Animals in control groups were engrafted with synoviocytes transduced with lacZ and neo marker genes. Cells continued to express transferred genes for at least 9 days after engraftment. We found that gene transfer of sIL-1ra significantly suppressed the severity of recurrence of arthritis, as assessed by measuring joint swelling and by the gross-observation score, and attenuated but did not abolish erosion of cartilage and bone. The effect of intraarticularly expressed sIL-1ra was essentially local, as there was no significant difference in severity of recurrence between unengrafted contralateral joints in control and experimental groups. We estimate that locally expressed sIL-1ra was about four orders of magnitude more therapeutically efficient than systemically administered recombinant sIL-1ra protein. These findings provide experimental evidence for the feasibility of antiinflammatory gene therapy for arthritis.

Retrovirus mediated in vivo gene transfer to synovium in bacterial cell wall-induced arthritis in rats.

Gene therapy may provide an effective alternative to conventional approaches for treating rheumatoid arthritis. Direct in vivo gene delivery to synovium has a distinct advantage with respect to clinical use. To date, retroviral vectors are the best studied constructs for gene delivery, and almost all approved gene therapy trials in humans rely on retroviral vectors. However, the applicability of retroviral transduction is limited by requirement for cell division, and attempts to transduce normal synovium in situ using retroviral vectors are reported to fail. The present study was undertaken in order to investigate susceptibility of inflamed synovium to retroviral infection in vivo. Using an experimental model of bacterial cell wall (BCW)-induced arthritis in rats, we attempted two approaches for delivery of retroviral vectors to synovium. In the first approach, recombinant retroviral vectors carrying reporter genes lacZ and neo were directly injected into inflamed rat ankle joints. Alternatively, inflamed joints were inoculated with gamma-irradiated murine retroviral vector-producing packaging cells. We found that about 1% of cells in explants from joints inoculated with packaging cells were lacZ-neo-positive. The lacZ+ neo+ cells in joint explants proliferated in culture and were of rat origin as determined using species-specific polymerase chain reaction (PCR) analysis. There was no evidence of transduction in explants from joints directly injected with retroviral vectors or from contralateral, control joints. These findings show that arthritic joints have a population of cells susceptible to retroviral infection in situ and demonstrate the possibility of using retroviral vectors for direct gene delivery to inflamed synovium.

Reactivation of arthritis induced by small bowel bacterial overgrowth in rats: role of cytokines, bacteria, and bacterial polymers.

Arthritis is often associated with intestinal diseases, but the etiology is not known. We developed a rat model whereby arthritis was reactivated by experimental small bowel bacterial overgrowth (SBBO). Self-limited monoarticular arthritis was induced by intra-articular injection of 2 micrograms of rhamnose peptidoglycan-polysaccharide derived from group A streptococci into the ankle joints in female Lewis rats. Eleven days after intra-articular injection, when swelling was resolving, experimental SBBO induced by surgical creation of jejunal self-filling blind loops reactivated arthritis, but SBBO induced by creation of self-emptying blind loops, which minimally increases luminal bacteria, and sham operation did not (P < 0.001). Increased joint diameters in rats with self-filling blind loops persisted for at least 56 days after surgery. Reactivation of arthritis due to SBBO was prevented by anti-tumor necrosis factor alpha antiserum and interleukin 1 receptor antagonist (P < 0.001), indicating that these cytokines mediate joint swelling secondary to intestinal injury. Recombinant bactericidal/permeability-increasing protein, an agent which neutralizes endotoxin, and metronidazole, which is active against anaerobic bacteria, prevented arthritis (P < 0.001), but polymyxin B (which also neutralizes endotoxin) and gentamicin had no effect. Mutanolysin, an enzyme which degrades peptidoglycan-polysaccharide from group A streptococci, exacerbated arthritis for the first 6 days but then diminished joint swelling from 12 to 21 days after surgery (P < 0.001). These studies introduce a reproducible animal model of reactivation of arthritis secondary to intestinal injury and demonstrate a role for bacterial products from endogenous enteric organisms.

Comparison of peptidoglycan-polysaccharide and lipopolysaccharide stimulation of Kupffer cells to produce tumor necrosis factor and interleukin-1.

Endotoxin (lipopolysaccharide) is a cell wall polymer from gram-negative bacteria that stimulates Kupffer cell release of cytokines such as tumor necrosis factor-alpha and interleukin-1. Another bacterial cell wall polymer in both gram-negative and gram-positive organisms is peptidoglycan-polysaccharide. Lipopolysaccharide and peptidoglycan-polysaccharide exist together in the intestinal lumen and can cross the intestinal mucosa, enter the portal vein and activate Kupffer cells. The purpose of this study was to compare the effects of lipopolysaccharide stimulation and peptidoglycan-polysaccharide stimulation of Kupffer cells on release of tumor necrosis factor-alpha and interleukin-1. Both bacterial polymers caused maximum tumor necrosis factor-alpha release from Kupffer cells after incubation for 4 to 8 hr. Maximum tumor necrosis factor-alpha release induced by 400 ng/ml lipopolysaccharide was 704 +/- 258 pg/ml, compared with 329 +/- 91 pg/ml tumor necrosis factor-alpha after 100 micrograms/ml peptidoglycan-polysaccharide (p < 0.001). Polymyxin B blocked lipopolysaccharide stimulation of tumor necrosis factor-alpha by 95% +/- 5% but blocked peptidoglycan-polysaccharide-stimulated tumor necrosis factor-alpha by 30% +/- 14% (p < 0.001). Repeat incubation of Kupffer cells with lipopolysaccharide after prior lipopolysaccharide incubation induced low tumor necrosis factor-alpha release (tolerance). Repeat incubation with peptidoglycan-polysaccharide induced no tolerance to tumor necrosis factor-alpha release. Incubation of lipopolysaccharide plus peptidoglycan-polysaccharide released less tumor necrosis factor-alpha than did each polymer used alone, but this inhibition was prevented by indomethacin. Dibutyryl cyclic AMP, prostaglandin E1, prostaglandin E2 and the adenosine A2-receptor agonist N-ethylcarboxyamideadenosine inhibited lipopolysaccharide-stimulated tumor necrosis factor-alpha release by 83%, 97%, 90% and 94%, respectively, but inhibited peptidoglycan-polysaccharide-stimulated tumor necrosis factor-alpha release by 52%, 60%, 45% and 51%, respectively (p < 0.001 for each). This indicates that intracellular signaling pathways differ for lipopolysaccharide-stimulated and peptidoglycan-polysaccharide-stimulated tumor necrosis factor-alpha release. After incubation for 8 and 24 hr, 100 micrograms/ml peptidoglycan-polysaccharide had induced significantly more interleukin-1 release from cultured Kupffer cells than had 400 ng/ml lipopolysaccharide (p < 0.001). Lipopolysaccharide induced tolerance to interleukin-1 release after repeat incubation, but peptidoglycan-polysaccharide caused no tolerance. These studies show that peptidoglycan-polysaccharide, a ubiquitous bacterial cell wall polymer, shares several proinflammatory properties with lipopolysaccharide but that there are differences that may have pathophysiological significance.

Phlogistic properties of peptidoglycan-polysaccharide polymers from cell walls of pathogenic and normal-flora bacteria which colonize humans.

PG-PS polymers which can induce experimental chronic inflammation in joints and other tissues can be isolated from the cell walls of human pathogens, such as group A streptococci, as well as from certain indigenous bacterial species which colonize the human intestinal tract. The structural and biological properties that are required for cell wall fragments to express this remarkable activity are still not well defined, but polymer size, resistance to tissue enzymes, and capacity to sustain activation of complement, macrophages, neutrophils, and T cells are properties associated with the most active preparations. There is increasing evidence that PG-PS structures with arthropathogenic activity occur in the human intestinal lumen and that these polymers can be translocated systemically. These observations support the concept that PG-PS, derived from a variety of bacterial species, can be part of the etiology of rheumatoid arthritis and other chronic inflammatory diseases. Since the PG component provides a common element to which all individuals are exposed, it follows that susceptibility is related to efficiency of disposal of bacterial cell wall debris, as well as to cytokine networks and immune cell function (51).

Bacterial cell wall polymers (peptidoglycan-polysaccharide) cause reactivation of arthritis.

Intraperitoneal (i.p.) injection of peptidoglycan-polysaccharide derived from group A streptococci (PG-APS) causes chronic arthritis with spontaneous remissions and exacerbations. We hypothesized that, following i.p. injection, PG-APS released from hepatic stores mediated spontaneous recurrences of arthritis. We tested whether transplanted livers with large amounts of PG-APS were able to reactivate quiescent arthritis. Saline-loaded (group 1) or PG-APS-loaded (group 2) livers were transplanted into rats which had been injected intra-articularly 10 days earlier with PG-APS in one joint and saline in the other. A comparison was made with the arthritis that occurred in rats injected i.p. with PG-APS which did not receive transplants (group 3). Arthritis was monitored by serial measurement of joint diameters. Transplantation of saline-loaded livers (group 1) caused no reactivation of arthritis. However, transplantation of PG-APS-loaded livers (group 2) reactivated arthritis (P < 0.0001). Injection of PG-APS i.p. (group 3) induced the most-severe arthritis. PG-APS levels in plasma decreased with time, and PG-APS accumulated in the spleen in groups 2 and 3. Plasma and hepatic levels of PG-APS in rats injected i.p. with PG-APS were greater than levels in rats transplanted with PG-APS-loaded livers, which in turn were greater than levels in rats with saline-loaded livers. Plasma tumor necrosis factor did not correlate with recurrence of arthritis. Transplantation with PG-APS-loaded livers induced reactivation of arthritis in preinjured joints. The extent of arthritis was proportional to hepatic PG-APS content. Reactivation of arthritis may be mediated by slow release of liver-sequestered PG-APS or cytokines (not tumor necrosis factor) released by the liver.

Superantigen can reactivate bacterial cell wall-induced arthritis.

Intravenous injection of toxic shock syndrome toxin-1 (TSST-1) produced by Staphylococcus aureus, can reactivate arthritis in a rat ankle joint that has been previously inflamed by injection of peptidoglycanpolysaccharide polymers isolated from the cell walls of group A streptococci. The severity and chronicity of this renewed arthritis is dose dependent and at higher doses (125 micrograms/kg) a prolonged joint inflammation with pannus formation and marginal erosion of cartilage and bone is induced after a single injection of TSST-1. Only modest synovial hyperplasia is induced in control ankle joints by systemic injection of TSST-1. Another superantigen, streptococcal pyrogenic exotoxin induces a much weaker, acute reactivation of arthritis that resolves by 2 days. Repeated injections of TSST-1 at 7-day intervals give the same undiminished pattern of joint response, but the joint swelling persists at a higher level with each succeeding injection. Cyclosporin A suppresses all phases of the recurrent arthritis, indicating that TSST-1 could be functioning through its property of a superantigen activating T lymphocytes. II-1 receptor antagonist and anti-TNF-alpha neutralizing antibody, which reduce reactivation of arthritis by peptidoglycan-polysaccharide polymers, have no effect on reactivation by TSST-1. This experimental model provides a means to examine in vivo the possible role of superantigens in rheumatoid arthritis and related diseases, and to analyze the cellular and molecular pathways induced by this family of microbial products.

Suppression of local and systemic responses in streptococcal cell wall-induced acute inflammation of the air pouch by cyclosporine A. Comparison with the effects of two anti-inflammatory bis-benzimidazoles.

Injection of streptococcus group A cell wall-derived peptidoglycan polysaccharide into a subcutaneous air pouch causes local outpouring of neutrophils and macrophages and distant hemopoietic proliferation in spleen and bone marrow. Cyclosporine A (CyA) suppressed neutrophil accumulation and all cell lines of hemopoiesis. trans-1,2-Bis(5-amidino-2-benzimidazolyl)ethene (BBE) also interfered with neutrophil exudation, yet reduced only the erythroid component of the hemopoietic process. The ethane analogue of BBE, on the other hand, did not prevent neutrophil emigration, but held down splenic erythropoiesis and myelopoiesis. All three compounds stimulated streptococcus group A cell wall-derived peptidoglycan polysaccharide uptake by pouch macrophages. CyA being the least active, BBE and its ethane analogue also produced a shift of wear-and-tear pigment from large numbers of small splenic macro-phages into small numbers of large macrophages. The pouch model is very useful in the study of anti-inflammatory compounds and has furnished the first evidence of CyA interference with massive neutrophilic infiltration and with hemopoietic signals.