Fibroblast activation and inflammation in frozen shoulder.

INTRODUCTION: Frozen shoulder is a common, fibro-proliferative disease characterised by the insidious onset of pain and progressively restricted range of shoulder movement. Despite the prevalence of this disease, there is limited understanding of the molecular mechanisms underpinning the pathogenesis of this debilitating disease. Previous studies have identified increased myofibroblast differentiation and proliferation, immune cell influx and dysregulated cytokine production. We hypothesised that subpopulations within the fibroblast compartment may take on an activated phenotype, thus initiating the inflammatory processes observed in frozen shoulder. Therefore, we sought to evaluate the presence and possible pathogenic role of known stromal activation proteins in Frozen shoulder. METHODS: Shoulder capsule samples were collected from 10 patients with idiopathic frozen shoulder and 10 patients undergoing shoulder stabilisation surgery. Fibroblast activation marker expression (CD248, CD146, VCAM and PDPN, FAP) was quantified using immunohistochemistry. Control and diseased fibroblasts were cultured for in vitro studies from capsule biopsies from instability and frozen shoulder surgeries, respectively. The inflammatory profile and effects of IL-1ß upon diseased and control fibroblasts was assessed using ELISA, immunohistochemistry and qPCR. RESULTS: Immunohistochemistry demonstrated increased expression of fibroblast activation markers CD248, CD146, VCAM and PDPN in the frozen shoulder group compared with control (p < 0.05). Fibroblasts cultured from diseased capsule produced elevated levels of inflammatory protein (IL-6, IL-8 & CCL-20) in comparison to control fibroblasts. Exposing control fibroblasts to an inflammatory stimuli, (IL-1ß) significantly increased stromal activation marker transcript and protein expression (CD248, PDPN and VCAM). CONCLUSIONS: These results show that fibroblasts have an activated phenotype in frozen shoulder and this is associated with inflammatory cytokine dysregulation. Furthermore, it supports the hypothesis that activated fibroblasts may be involved in regulating the inflammatory and fibrotic processes involved in this disease.

Adhesive capsulitis: An age related symptom of metabolic syndrome and chronic low-grade inflammation?

Adhesive capsulitis (AC) is very poorly understood, particularly it's underlying etiology. Obesity and metabolic syndrome, which are strongly associated with chronic low grade inflammation, are becoming increasingly understood to underlie a raft of morbid states including upper limb pain syndromes, diabetes (DM), cardiovascular disease (CVD), cancer and central nervous system dysfunction and degeneration. Notwithstanding age, two of the strongest established risk factors for AC are DM and CVD. The hypothesis argues that similar to DM and CVD, the inflammation and capsular fibrosis seen in AC is precipitated by metabolic syndrome and chronic low grade inflammation. These pathophysiological mechanisms are highly likely to be perpetuated by upregulation of pro-inflammatory cytokine production, sympathetic dominance of autonomic balance, and neuro-immune activation. The hypothesis predicts and describes how these processes may etiologically underpin and induce each sub-classification of AC. An improved understanding of the etiology of AC may lead to more accurate diagnosis, improved management, treatment outcomes, and reduce or prevent pain, disability and suffering associated with the disease. The paper follows on with a discussion of similarities between the pathophysiology of AC to general systemic inflammatory control mechanisms whereby connective tissue (CT) fibrosis is induced as a storage depot for leukocytes and chronic inflammatory cells. The potential role of hyaluronic acid (HA), the primary component of the extracellular matrix (ECM) and CT, in the pathophysiology of AC is also discussed with potential treatment implications. Lastly, a biochemical link between physical and mental health through the ECM is described and the concept of a periventricular-limbic central driver of CT dysfunction is introduced.

Candida glabrata olecranon bursitis treated with bursectomy and intravenous caspofungin.

Orthopedic surgeons are becoming more involved in the care of patients with septic arthritis and bursitis caused by yeast species. This case report involves a middle-aged immunocompromised female who developed a Candida glabrata septic olecranon bursitis that developed after she received a corticosteroid injection in the olecranon bursa for presumed aseptic bursitis. Candida (Torulopsis) glabrata is the second most frequently isolated Candida species from the bloodstream in the United States. Increased use of fluconazole and other azole antifungal agents as a prophylactic treatment for recurrent Candida albicans infections in immunocompromised individuals is one reason why there appears to be increased resistance of C. glabrata and other nonalbicans Candida (NAC) species to fluconazole. In this patient, this infection was treated with surgery (bursectomy) and intravenous caspofungin, an echinocandin. This rare infectious etiology coupled with this intravenous antifungal treatment makes this case novel among cases of olecranon bursitis caused by yeasts.

Interleukin-1ß stimulates stromal-derived factor-1α expression in human subacromial bursa.

Chemokines produced by synoviocytes of the subacromial bursa are up-regulated in subacromial bursitis and rotator cuff disease. We hypothesized that SDF-1α production in bursal synoviocytes may be induced by local cytokines such as interleukin IL-1ß and IL-6. Subacromial bursa specimens were obtained from patients undergoing shoulder surgery. Bursal specimens were stained with anti-human antibodies to IL-1, IL-6, and SDF-1α by immunohistochemistry and compared to normal and rheumatoid controls. Bursal cells were also isolated from specimens and cultured. Early passaged cells were then treated with cytokines (IL-1ß and IL-6) and SDF-1α expression was measured by ELISA and RT-PCR. SDF-1α, IL-1ß, and IL-6 were expressed at high levels in bursitis specimens from human subacromial bursa compared to normal controls. In cultured bursal synoviocytes, there was a dose-dependent increase in SDF-1α production in the supernatants of cells treated with IL-1ß. SDF-1α mRNA expression was also increased in bursal cells treated with IL-1ß. IL-6 caused a minimal but not statistically significant increase in SDF-1α expression. SDF-1α, IL-1ß, and IL-6 are expressed in the inflamed human subacromial bursal tissues in patients with subacromial bursitis. In cultured bursal synoviocytes, SDF-1α gene expression and protein production are stimulated by IL-1ß. IL-1ß produced by bursal syvoviocytes and inflammatory cells in the human subacromial bursa is an important signal in the inflammatory response that occurs in subacromial bursitis and rotator cuff disease.

Olecranon bursitis secondary to Mycobacterium kansasii infection in a patient receiving infliximab for Behcet's disease.

We present a case of Mycobacterium kansasii olecranon bursitis in a woman with known immunosuppression secondary to the treatment received for her Behçet's disease. We found only one other case report of olecranon bursitis caused by M. kansasii in the literature, which, unlike our case, presented in an immunocompetent adult following trauma. This case extends the range of opportunistic mycobacterial infections that are associated with anti-tumour necrosis factor therapy.

Trochanteric bursitis: refuting the myth of inflammation.

BACKGROUND AND OBJECTIVES: Greater trochanteric (GT) bursitis is a common cause of hip pain. Previously, the etiology of the trochanteric pain syndrome was thought to be caused by inflammation of the subgluteus maximus bursa (i.e., bursitis). Recently, MRI and ultrasound studies have brought into serious doubt the idea that bursitis is the etiology for trochanteric pain. To our knowledge, no histologic study of GT bursitis has been reported to date. The purpose of this study is to evaluate the histopathology of patients with and without the clinical syndrome of GT bursitis to assess for the presence of bursal inflammation. DESIGN AND METHODS: This is a prospective, case-controlled, blinded study of the histopathologic features of controls and patients with GT bursitis. We recruited patients who required total hip arthroplasty (THA) for rheumatoid or osteoarthritis. Inclusion criteria for the study consisted of the following: needing THA as standard of care; THA secondary to OA or RA; age greater than 18; and minimal risk for surgery by the American Heart Association Criteria. We excluded anyone who received a GT bursa injection 9 months before surgery. Eligible participants were then stratified as cases or controls using the 1985 clinical criteria for GT bursitis. The harvesting of the bursa required no modification of the surgical procedure. The specimens were then examined by 2 independent pathologists who were blinded as to the patients' clinical status. RESULTS: Six bursal specimens were evaluated by 2 blinded surgical pathologists revealing primarily fibroadipose tissue with no signs of acute or chronic inflammation. There were 3 bursas in the control group and 2 specimens with clinical GT bursitis. No significant differences were found between the specimens of the 2 groups. CONCLUSIONS: The results of this small prospective observational histologic study, along with recent MRI and ultrasound studies on the topic, strongly suggest that there is no etiologic role of bursal inflammation in the trochanteric pain syndrome.

Stromal cell-derived factor 1 (SDF-1, CXCL12) is increased in subacromial bursitis and downregulated by steroid and nonsteroidal anti-inflammatory agents.

Several studies have demonstrated that inflammation in the subacromial bursa is an important component in the pathogenesis of impingement syndrome. We have demonstrated in a previous study that many inflammatory cytokines, including stromal cell-derived factor 1 (SDF-1, CXCL12), are increased in the subacromial bursa [Blaine et al. 2005. J Shoulder Elbow Surg 14(Suppl 1):84S-89S]. SDF-1 is a potent chemotactic and angiogenic factor that stimulates recruitment of inflammatory cells. In the current study, we proposed that the resident cells in subacromial bursal tissue produce SDF-1, which can play a role in the inflammatory reponse of bursal tissue, and that this chemokine can be regulated by steroid (dexamethasone) and nonsteroidal anti-inflammatory medications (NSAIDs). Twenty-two subacromial bursa tissues (18 bursitis and 4 normal bursa) were obtained intraoperatively from patients during shoulder surgery and analyzed using the cDNA Array technique in accordance with an IRB approved protocol. cDNA array results were confirmed with real-time reverse transcription-polymerase chain reaction (RT-PCR). Bursal cells (from 4 normal bursa, 3 bursitis) and two normal bone marrow with whole tissue explants were cultured for one passage. Cell culture supernatants were collected and SDF-1 protein was detected with enzyme-linked immunosorbent assay (ELISA). Cultured bursal cells were treated with a COX-2 inhibitor and dexamethasone, and cells was harvested at 1-day and 4-day intervals. SDF-1 expression was evaluated by real-time RT-PCR and ELISA. cDNA Array analysis demonstrated that the gene expression of SDF-1 was increased in patients with subacromial bursitis compared to controls (p < 0.05). Real-time RT-PCR also revealed that the mRNA expression of SDF-1 in bursitis tissue is increased 10-fold over control tissue. While the normal bursal cells produced negligible amounts of SDF-1 protein, cultured cells derived from bursitis lesion released as much SDF-1 protein (235 pg/100,000 cells) as normal bone marrow stromal cells (283 pg/100,000 cells) as measured by ELISA. The addition of a COX-2 inhibitor and dexamethasone to bursitis cell lines led to decreased SDF-1 expression levels compared to untreated bursitis cell lines. These studies demonstrate that there is a significant elevation of SDF-1 expression in the subacromial bursa of patients with rotator cuff disease. Furthermore, this chemokine can be downregulated by COX-2 inhibitors and steroids. These results provide biologic evidence for the use of steroid and NSAIDs in the treatment of subacromial bursitis. In the future, targeted inhibition of molecules such as SDF-1 in the subacromial bursa may present a therapeutic strategy that may avoid the side effects of these other (steroid and NSAID) medications.

Immunocytologic characteristics of mononuclear cell populations found in nonseptic olecranon bursitis.

OBJECTIVE: To determine the immunocytologic characteristics of the various subsets of nonseptic olecranon bursal fluid mononuclear cells. METHODS: Twenty consecutive patients with culture negative olecranon bursitis had immunocytochemical and flow cytometric analysis performed using a panel of monoclonal antibodies to determine lymphocyte and monocyte/macrophage population subtypes and proportions. RESULTS: In traumatic bursitis (n = 9), the mean (+/- SD) white blood cell (WBC) count/mm3 was 1,368 +/- 1,559; WBC mononuclear differential count was 29.5 +/- 19% lymphocytes and 55 +/- 26% monocyte/macrophages. In idiopathic bursitis (n = 11), the mean WBC/mm3 was 376 +/- 515; WBC mononuclear differential count was 28.5 +/- 16% lymphocytes and 52 +/- 27% monocytes/macrophages. Flow cytometry revealed 88% CD2+ T lymphocytes in the lymphocyte population, 3% B lymphocytes and CD4/CD8 T cell mean ratio of 2.5 +/- 1.5 for traumatic bursitis and 88% CD2+ T lymphocytes, 4% B lymphocytes and CD4/Cd8 ratio of 1.4 +/- 0.6 for idiopathic bursitis (p < 0.05, t test). Both groups contained increased proportions of lymphocyte subtypes expressing activation markers: CD25+, CD26+ and HLA DR+ compared to normal peripheral blood. In traumatic bursitis, the mean percent of CD14+ cells (monocyte/macrophages) was 62 +/- 24; in idiopathic bursitis, the mean percent was 51 +/- 28. The vast majority expressed high levels of HLA-DR indicating activation. CONCLUSION: We observed a preponderance of activated T cell subpopulations and monocyte/macrophages suggesting an immunologic role for these cell populations in the development and perpetuation of nonseptic bursitis.

Inflammation of the subacromial bursa in chronic shoulder pain.

Subacromial bursal tissue was studied in 12 patients operated on for painful (10 patients with constant pain and 2 patients with pain on motion) rotator cuff tendinitis/impingement syndrome. The Neer acromioplasty technique was used. Six patients had moderate inflammatory changes and one had a slight inflammation. In three of the five remaining patients, the subacromial bursa did not show any signs of inflammatory involvement, but patients experienced pain at rest and at night, reflecting clinical inflammation in tissues other than the bursa. The two patients with pain only on strain did not show inflammation of the bursa. Immunohistochemical typing of the bursal tissue disclosed a typical chronic mononuclear cell infiltrate consisting mainly of CD2-positive T lymphocytes (50-80% of all inflammatory cells), accompanied by less frequent CD11b (C3bi receptor)-positive monocyte/macrophages (10-40%). The relative paucity of plasmablasts/plasma cells expressing PCA-1 suggests this to be an inflammatory rather than an immune response. Active involvement of some of the local cells is suggested to be the source of algogenic and hyperalgesic substances contributing to pain in chronic shoulder pain syndromes.