Mark Coleman

Microarchitecture and protective mechanisms in synovial tissue from clinically and arthroscopically normal knee joints

Background: Synovial biopsies are used to study synovial immunopathology and are increasingly applied for the evaluation of new therapeutic strategies in chronic arthritis. Therefore, it is essential to be informed on the complete spectrum of synovial immunopathology. Objective: To describe the cellular content, cytokine and cell adhesion molecule expression in synovial tissue from clinically and arthroscopically normal knees. Methods: Synovial tissue was obtained from 20 normal subjects at the time of knee joint arthroscopy for unexplained knee pain. Tissue sections were studied for basic histopathology and for a range of cell surface markers, cytokines, and cell adhesion molecules by immunoperoxidase staining. Stained sections were evaluated by semiquantitative scoring and digital image analysis. Results: Normal synovial tissue is composed predominantly of fibrofatty areolar tissue, with a variable thickness of intimal lining, composed of both CD68 positive macrophages and CD55 positive fibroblast-like synoviocytes. Interleukin 1 receptor antagonist (IL1Ra) was frequently detected in the synovial membrane of normal subjects (mean (SD) integrated optical density (IOD)=3809.6 (3893.9)), but both tumour necrosis factor α (TNFα) and interleukin 1β (IL1β) were rarely detected. In addition, cell adhesion molecules were rarely detected in the normal synovial membrane, with the exception of intercellular cell adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1). Osteoprotegerin (OPG) expression was abundant on synovial lining macrophages (mean (SD) IOD=5276 (4716) as well as endothelial cells (mean (SD) IOD=557 (226)), but receptor activator of nuclear factor κ ligand (RANKL) expression was rarely seen. Conclusions: The normal synovial membrane has a variable architecture, including thickness of the lining and the subintimal cell infiltrate, with little inflammatory cytokine production or expression of cell adhesion molecules. The excess of OPG expression over RANKL and IL1Ra over IL1 may be important for protection against joint damage

Isolated pulmonary hypertension in scleroderma

Background: Isolated pulmonary hypertension (PHT) is now the most frequent cause of disease‐related death in limited cutaneous scleroderma, the commonest disease variant of this disabling connective tissue disorder. Endothelin‐1 receptor antagonists provide symptomatic benefit but to date have not been shown to prolong survival.

Scleroderma renal crisis: poor outcome despite aggressive antihypertensive treatment

Background:  Scleroderma renal crisis (SRC) is a rare but feared complication of scleroderma. Angiotensin‐converting enzyme (ACE) inhibition has significantly improved survival, but it is unknown whether prophylactic ACE inhibitors will prevent this complication.

Characterisation of a dendritic cell subset in synovial tissue which strongly expresses Jak/STAT transcription factors from patients with rheumatoid arthritis

Objectives: To characterise the phenotype of the putative dendritic cells strongly expressing Jak3 and STAT4, which have been previously identified in the synovial tissue of patients with active rheumatoid arthritis (RA). Methods: Synovial biopsy specimens were obtained at arthroscopy from 30 patients with active RA (42 synovial biopsies). Immunohistological analysis was performed using monoclonal antibodies to detect dendritic cell subsets, including activation markers and cytokines relevant to dendritic cell function. Co-localisation of cell surface markers and cytokines was assessed primarily using sequential sections, with results confirmed by dual immunohistochemistry and immunofluorescence with confocal microscopy. Results: The dendritic cells identified in RA synovial tissue that strongly express Jak3 also strongly express STAT4 and STAT 6 and are correlated with the presence of serum rheumatoid factor. These cells are not confined to a single dendritic cell subset, with cells having phenotypes consistent with both myeloid- and plasmacytoid-type dendritic cells. The activation status of these dendritic cells suggests that they are maturing or mature dendritic cells. These dendritic cells produce IL12 as well as interferon α and γ. Conclusions: The close correlation of these dendritic cells with the presence of serum rheumatoid factor, a prognostic factor for worse disease outcome, and the strong expression by these cells of components of the Jak/STAT transcription factor pathway suggest a potential therapeutic target for the treatment of RA.

Changes in synovial tissue Jak-STAT expression in rheumatoid arthritis in response to successful DMARD treatment.

Background: Modulation of Jak-STAT signalling may provide an effective therapeutic strategy in inflammatory arthritis (IA). Objective: To examine the effect of successful disease-modifying antirheumatic drug (DMARD) treatment on the expression of Jak-STAT in a cohort of patients with active rheumatoid arthritis. Methods: Synovial tissue biopsy specimens from 16 patients with active rheumatoid arthritis, taken before and after initiation of DMARD treatment, were examined for the presence of janus kinase (Jak)3, signal transducer and activator of transcription (STAT)1, STAT4 and STAT6 expression using immunohistochemistry. Results: Successful treatment with DMARDs results in reduction in STAT1 expression in the lining, and STAT1 and STAT6 in the sublining of rheumatoid arthritis synovial tissue. Although the overall expression of STAT4 and Jak3 was not significantly altered by DMARD treatment, there was a significant reduction in the expression of the STAT4 and Jak3 bright cells, thought to be an activated dendritic cell subpopulation. Conclusion: Results show that Jak3, STAT1, STAT4 expression and STAT6 sublining expression decrease in response to successful treatment of rheumatoid arthritis with standard DMARDs. Therefore, altering the expression of these pathways may represent an alternative treatment option, either through promoting up-regulation of inhibitory pathways, or suppressing inflammatory paths.

Pathogenic mechanisms in the rheumatoid nodule: Comparison of proinflammatory cytokine production and cell adhesion molecule expression in rheumatoid nodules and synovial membranes from the same patient

OBJECTIVE To investigate the production of proinflammatory cytokines and expression of cell adhesion molecules in the rheumatoid nodule. METHODS Cytokine content (tumor necrosis factor alpha [TNFalpha], interleukin-1beta [IL-1beta], and IL-1 receptor antagonist [IL-1Ra]), at the messenger RNA (mRNA) and protein levels, and cell adhesion molecule expression were studied in 16 rheumatoid nodules and 6 synovial membranes. RESULTS Macrophages in the rheumatoid nodules contained TNFalpha, IL-1beta, and IL-1Ra mRNA and protein, particularly in perivascular cells of the stroma and in the palisading layer. All cell adhesion molecules studied were expressed in both the rheumatoid nodules and synovial membranes, with increased expression of E-selectin in the rheumatoid nodule compared with the synovial membrane, and with the absence of vascular cell adhesion molecule 1 expression on cells of the palisading layer in the rheumatoid nodule. CONCLUSION The presence of similar proinflammatory cytokines and cell adhesion molecules in the rheumatoid nodule and synovial membrane suggests that similar pathogenic processes result in the chronic inflammation and tissue destruction in these lesions.

Aggressive mixed epithelial-stromal tumour of the kidney treated with chemotherapy and radiotherapy

Mixed epithelial-stromal tumour of the kidney is a distinct category of renal neoplasm, defined by Michal and Syrucek. Increasingly recognised over the past few years, this typically benign bimorphic lesion is characterised morphologically by admixed solid and cystic regions that have variable cellularity and growth patterns. We report an unusual case of mixed epithelial-stromal tumour of the kidney, which recurred soon after definitive surgery in an aggressive manner. Because most cases have been reported as benign localised disease amenable to surgical resection, little information is available on treatment of these tumours with chemotherapy. In this patient, chemotherapy resulted in a symptomatic response. A 53-year-old woman presented in July, 2001, with abdominal discomfort from a very large mass in her right upper quadrant. Abdominal ultrasound showed a large cystic mass abutting the liver and the right kidney. CT showed a well-circumscribed 18 18 26 cm mass with solid and cystic components. The mass arose from the right kidney and displaced the right kidney and inferior vena cava medially. The patient underwent right nephrectomy and tumour excision. At surgery, the tumour had the appearance of a large rubber sponge infiltrating from the kidney into the perirenal adipose tissue; other organs had not been invaded. The tumour ruptured during surgery and was removed in fragments. Postoperative adjuvant treatment was not given. Pathological examination showed an unusual bimorphic tumour consisting of multicystic and solid components (figure 1A). The kidney was partly replaced by circumscribed tumour, which was extensively disrupted and fragmented. The relations with the perinephric fat and renal fascia were lost. Neither the venous nor the urinary collecting systems seemed to be involved by the tumour. Excision margins were clear. The cysts or tubules were simple and were lined by benign cuboidal epithelium (figure 1B). The solid component of the tumour consisted mainly of a spindle-cell proliferation of

Modulation of RANKL and osteoprotegerin expression in synovial tissue from patients with rheumatoid arthritis in response to disease-modifying antirheumatic drug treatment and correlation with radiologic outcome

OBJECTIVE To demonstrate the effect of treatment with disease-modifying agents on the expression of osteoprotegerin (OPG) and RANKL in the synovial tissue from rheumatoid arthritis (RA) patients and to correlate these changes with radiologic damage measured on sequential radiographs of the hands and feet. METHODS Synovial biopsy specimens were obtained at arthroscopy from 25 patients with active RA (16 of whom had a disease duration <12 months) before and at 3-6-month intervals after starting treatment with a disease-modifying agent. Immunohistologic analysis was performed using monoclonal antibodies to detect OPG and RANKL expression, with staining quantitated using computer-assisted image analysis and semiquantitative analysis techniques. Serial radiographs of the hands and feet were analyzed independently by 2 radiologists and a rheumatologist using the van der Heide modification of the Sharp scoring method. RESULTS Thirteen patients achieved a low disease state as defined by a disease activity score <2.6 while 19 patients achieved an American College of Rheumatology response >20% after disease-modifying antirheumatic drug (DMARD) treatment. Successful DMARD treatment resulted in an increase in OPG expression and a decrease in RANKL expression at the synovial tissue level, which correlated with a reduction in erosion scores measured on annual radiographs of the hands and feet. CONCLUSION Successful treatment-induced modulation of OPG and RANKL expression at the synovial tissue level, resulting in a reduction in the RANKL:OPG ratio, is likely to have a significant impact on osteoclast formation and joint damage in patients with active RA.

Renal prothrombin mRNA is significantly decreased in a hyperoxaluric rat model of nephrolithiasis

Although urinary prothrombin fragment 1 (UPTF1) possesses several hallmarks expected of a regulatory protein in urolithiasis, its precise role remains unknown. To determine the relationship between renal prothrombin (PT), the parent molecule of UPTF1, and lithogenesis, this study quantified and compared levels of renal PT mRNA in healthy rats (n = 10) and rats rendered lithogenic (n = 10) by ingestion of 0.75% ethylene glycol for 8 weeks. Studies included morphological and histological examination of the kidneys with scanning electron microscopy of the urinary filtrates of control and experimental animals. Haematuria and calcium oxalate (CaOx) crystals occurred in the urine of all experimental rats, but not in those of controls. Histological examination showed birefringent nephroliths and associated damage in kidneys of lithogenic rats, which were not seen in the control group. The amounts of total RNA extracted from both groups of rats were similar, but the median ratio of PT to β‐actin transcript of 11.14 × 10−4(10.65 × 10−4 ± 2.24 × 10−4) in the control rats was significantly (p ≤ 0.001) reduced to 6.47 × 10−4(6.57 × 10−4 ± 2.72 × 10−4) in the lithogenic group. These results demonstrate that renal PT mRNA is reduced by ∼42% in lithogenic rats and confirm the existence of a direct association between renal PT synthesis and calculogenesis. Attempts to compare renal PT and urinary levels of PTF1 were unsuccessful because of interference from hepatic PT circulating in the blood, haematuria, and the presence of urinary CaOx crystals. This is the first report of a significant reduction in the renal expression of a urinary protein well documented to inhibit CaOx crystal growth and aggregation in undiluted human urine in vitro. Copyright

Risk of cancer in patients with biopsy-proven giant cell arteritis

OBJECTIVE Results of previous studies investigating the association between GCA and malignancy are conflicting. We performed a study of the risk of cancer in patients with biopsy-proven GCA. METHODS Patients with biopsy-proven GCA were identified from pathology reports of temporal artery biopsies from the major pathology laboratories in South Australia (SA). All subjects with biopsy-proven GCA were linked to the SA Cancer Registry to identify cases of cancer until 31 December 2006. Standardized incidence ratios (SIRs) for cancer were determined using the age- and gender-specific rates for SA. RESULTS There were 226 cases of biopsy-proven GCA (163 females and 63 males). Thirty-one cases were diagnosed with cancer, following the diagnosis of biopsy-proven GCA. There was no increased risk of cancer among those with biopsy-proven GCA, following the diagnosis of GCA compared with the general population (SIR 1.2; 95% CI 0.8, 1.6). CONCLUSION This cohort study did not demonstrate any increased risk for malignancy in subjects with biopsy-proven GCA.