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Biomedical subjects

M J Ahern

Publications and source records attributed to M J Ahern.

At least 37 records · Page 2Linked to original sources
PubMed2001

Comparison of differentiated dendritic cell infiltration of autoimmune and osteoarthritis synovial tissue.

OBJECTIVE: Infiltration of rheumatoid arthritis (RA) synovial tissue (ST) by differentiated dendritic cells (DC) is a consistent feature in patients with active disease. However, mononuclear cells (MNC), including DC, may be nonspecifically chemoattracted to inflammatory sites regardless of etiology. Therefore, to evaluate the specificity of ST infiltration by differentiated DC, synovial biopsies from patients with RA, spondylarthropathy (SpA), osteoarthritis (OA), and gout were examined. METHODS: Formalin-fixed ST sections were analyzed by double immunohistochemical staining for vascularity and infiltration by differentiated DC, lymphocytes, and macrophages. RESULTS: DC containing nuclear RelB were found in perivascular MNC aggregates from patients with all arthritides studied. Infiltration by differentiated DC was similar in RA and SpA ST, but reduced in OA ST. Differentiated DC were always observed in close association with lymphocytes, and the correlation between these variables suggested that the infiltration of inflammatory sites by DC and lymphocytes was associated. CONCLUSION: Perivascular infiltration by DC, lymphocytes, and macrophages is nonspecifically related to inflammation, but signals present in RA and SpA ST lead to more intense cellular infiltration and accumulation.

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PubMed2001

Effects of intraarticular glucocorticoids on macrophage infiltration and mediators of joint damage in osteoarthritis synovial membranes: findings in a double-blind, placebo-controlled study.

OBJECTIVE: To investigate the effects of intraarticular glucocorticoid treatment on macrophage infiltration, the expression of the chemokines monocyte chemoattractant protein 1 (MCP-1) and macrophage inflammatory protein 1alpha (MIP-1alpha), and the expression of matrix metalloproteinases 1 and 3 (MMPs 1 and 3) and their inhibitors, the tissue inhibitors of metalloproteinases 1 and 2 (TIMPs 1 and 2), in osteoarthritis (OA) synovial membranes. METHODS: Forty patients underwent arthroscopic biopsy before and 1 month after intraarticular injection of glucocorticoids. Twenty-one patients received 120 mg of methylprednisolone acetate (Depo-Medrol; Upjohn, Kalamazoo, MI), and 20 patients received placebo (1 patient received placebo in 1 knee and methylprednisolone acetate in the other). Immunoperoxidase staining for the expression of CD68, MCP-1, MIP-1alpha, MMP-1, MMP-3, TIMP-1, and TIMP-2 was performed, and the immunostaining was quantified by color video image analysis. RESULTS: CD68, MCP-1, MIP-1alpha, MMP-1, MMP-3, TIMP-1, and TIMP-2 immunostaining was observed in all synovial membranes. Intraarticular glucocorticoid treatment was associated with a small (30%) but statistically significant (P = 0.048) reduction in CD68+ macrophage staining in the synovial lining layer, but there was no change in the CD68 expression in the synovial sublining layer. No significant differences were observed for MCP-1, MIP-1alpha, MMP-1, MMP-3, TIMP-1, and TIMP-2 immunostaining in the synovial lining or sublining layers. CONCLUSION: Intraarticular glucocorticoids may reduce CD68+ macrophage infiltration into the synovial lining layer, but not the expression of MCP-1, MIP-1alpha, MMP-1, MMP-3, TIMP-1, and TIMP-2 in the synovial membrane, in patients with OA.

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PubMed2001

Treatment-induced remission in rheumatoid arthritis patients is characterized by a reduction in macrophage content of synovial biopsies.

OBJECTIVES: To document the change in synovial membrane macrophage and T-lymphocyte content in rheumatoid arthritis (RA) patients who achieve remission induced by disease-modifying anti-rheumatic drugs (DMARDs). METHODS: Arthroscopic synovial biopsies were taken from four to seven sites around a knee joint in 13 patients with RA before and at regular intervals after commencing treatment with a DMARD. The cellular content of synovial membrane biopsies taken at regular intervals for a period of up to 3 yr after commencing treatment was quantitated by routine histopathology and immunohistochemical labelling with anti-macrophage (CD68) and anti-T lymphocyte (UCHL-1) antibodies. Synovial biopsies were quantitated with a validated semiquantitative scoring system and video image analysis. RESULTS: Nine patients obtained clinical remission, as defined by American College of Rheumatology (ACR) criteria. The changes that occurred in the synovial biopsies included a reduction in lining layer thickness, reduced vascularity and cellular infiltrate. The most significant reduction in cellular infiltrate was in the lining layer macrophages, with less dramatic change in the subintimal macrophage infiltrate. Although there was a reduction in CD45 Ro-positive T lymphocytes in the synovial membranes of patients who attained ACR-defined disease remission, it was less significant than the reduction in macrophage content of the synovial membranes and tended to plateau at a reduced level of T-cell infiltration. CONCLUSIONS: Remission in RA patients is characterized by a predominant reduction in macrophage content of the synovial membrane, suggesting that current DMARDs may target this cell and its inflammatory mediators.

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PubMed2001

Successful treatment of rheumatoid arthritis is associated with a reduction in synovial membrane cytokines and cell adhesion molecule expression.

OBJECTIVE: To investigate the change in synovial membrane cytokine content and cell adhesion molecule expression in sequential biopsies from the same knee joint of patients with rheumatoid arthritis, before and following anti-rheumatic drug treatment and to assess the relationship of these changes with clinical responses to the drug treatment. METHODS: A selected group of patients with rheumatoid arthritis, some of whom had achieved a disease remission based on American College of Rheumatology (ACR) criteria, were included in this study. Sequential synovial biopsies obtained before and throughout the treatment period were studied by immunohistochemical labelling techniques for the cellular content, production of a range of pro- and anti-inflammatory cytokines and the expression of cell adhesion molecules. The staining was quantitated using computer-assisted digital image analysis. RESULTS: There was a decrease in tumour necrosis factor-alpha (TNFalpha) and interleukin-1beta (IL-1beta) production in the synovial membrane lining and sublining of all patients who responded to treatment. The changes in IL-1 receptor antagonist production were variable. Paradoxically, there was a trend to decreased synovial membrane production of the anti-inflammatory cytokines, IL-10 and transforming growth factor-beta (TGFbeta), while IL-4 was not detectable in any of the synovial membrane biopsies. A significant reduction in the density and total amount of E-selectin expression in the synovial membrane was seen. Similarly, intercellular adhesion molecule-1 (ICAM-1) expression in the lining and sublining was decreased in those patients who had a significant clinical response to drug treatment or attained disease remission. There were no consistent or significant changes seen in the expression of other cell adhesion molecules in the synovial membranes of these patients. CONCLUSIONS: Successful drug treatment of rheumatoid arthritis patients is characterized at the synovial membrane level by a decrease in TNFalpha, IL-10 and TGFbeta production. Some (E-selectin and ICAM-1) but not all (P-selectin, VCAM-1, PECAM-1) cell adhesion molecules are modulated in patients who respond clinically to drug treatment. E-selectin and ICAM-1 may be important targets for the development of future drug treatments for rheumatoid arthritis.

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PubMed2001

Measurement of cytokine and adhesion molecule expression in synovial tissue by digital image analysis.

OBJECTIVE: Digital image analysis (DIA) offers the opportunity to quantify the stained area and staining intensity when synovial tissue (ST) is investigated by immunohistochemical analysis. This study aimed at determining the sensitivity of DIA compared with semiquantitative analysis (SQA). METHODS: Paired ST samples were obtained from the knee joint of 10 patients with rheumatoid arthritis (RA) with active disease and after follow up when complete clinical remission was achieved. ST samples of 10 subjects with non-inflammatory knee pain served as controls. Immunohistochemistry with antibodies against interleukin 1beta (IL1beta) and vascular cell adhesion molecule 1 (VCAM-1) was applied using two staining protocols with 3-amino-9-ethylcarbazole (AEC) or p-diethylaminobenzaldehyde (DAB) as dye. All sections were analysed semiquantitatively (0-4) and DIA of up to a maximum of 60 high power fields (HPF). The average integrated optical density was calculated as the product of the stained area (corrected for total tissue area) and the optical density. RESULTS: Both SQA and DIA enabled the assessment of differences in IL1beta and VCAM-1 expression between ST from active RA, RA in remission, and controls. SQA and DIA showed excellent correlations (IL1beta rs=0.867; p<0.0001: VCAM-1 rs=0.828; p<0.0001). A limited analysis of one region with six HPF still allowed adequate discrimination compared with an extended analysis of three regions with a total of 60 HPF. In general, the red dye (AEC) resulted in better discrimination than the brown (DAB) staining. CONCLUSION: DIA offers a reliable, reproducible, and sensitive analysis of ST sections stained for cytokines and adhesion molecules.

Adult↗
PubMed2001

Prevention of corticosteroid induced osteoporosis in inpatients recently discharged from a tertiary teaching hospital.

OBJECTIVE: To determine the medical conditions for which oral corticosteroids are prescribed and to determine the frequency and type of osteoporosis prophylaxis offered to these patients. METHODS: Medical records of all inpatients for the period March to October 1999 who were documented in pharmacy records as either having received continuous oral steroids for at least 3 months or who had at least 4 courses of oral steroids per year were examined for the following data: age, sex, medical condition for which steroids were required, dose and duration of steroid therapy, whether they were offered bone mineral density (BMD) scans, and whether they were offered drug prophylaxis for steroid induced osteoporosis and the type of drug prophylaxis offered. Followup telephone calls were made to verify patients' use of prophylactic treatment and to validate the chronic use of oral corticosteroids. Use of BMD testing was also validated by comparing the list of patients in this study with the records of bone densitometer units in the area. RESULTS: A total of 189 medical records were examined: 38% were women (n = 72) and 62% were men (n = 117), with an age range of 19-91 years; 73% were taking continuous steroid therapy, the remaining 27% had multiple courses of prednisolone through the year. Steroids were prescribed for respiratory (n = 82, 43%), rheumatological (n = 74, 39%), hematological (n = 16, 8%), dermatological (n = 8, 4%), and gastrointestinal conditions (n = 7, 4%). Chronic obstructive airway disease was the most common respiratory condition for which steroids were prescribed (77, 94%), and polymyalgia rheumatica (36%) and inflammatory arthritis (41%) were the most common rheumatological conditions for which steroids were prescribed. In total, 47% (n = 89) were offered BMD scans while 53% (n = 100) were not. Of the 100 patients not offered BMD scans, 21 (21%) were receiving some form of drug prophylaxis, while 79% of patients were not taking any form of drug prophylaxis. Prophylaxis consisted of calcitriol (64%), alendronate (11%), calcitriol and calcium (7%), calcium alone (7%), alendronate and calcium (3%), etidronate and calcium (2%), alendronate, calcitriol and calcium (1%), alendronate and calcitriol (1%), and hormone replacement therapy (4%). Rheumatologists utilized both BMD testing and prophylactic treatment twice as often in patients taking chronic oral corticosteroid treatment than other specialty physicians. CONCLUSION: Compared to literature reports, the use of prophylaxis for corticosteroid induced osteoporosis was relatively high at this teaching hospital, with a surprisingly large number of patients receiving this treatment with no monitoring by BMD measurements.

Administration, Oral↗
PubMed2001

Missing a therapeutic window of opportunity: an audit of patients attending a tertiary teaching hospital with potentially osteoporotic hip and wrist fractures.

OBJECTIVE: To establish the rate of and the predictors for performance of a bone mineral density (BMD) test and the treatment of osteoporosis in an at-risk cohort of patients attending a tertiary teaching hospital with fracture possibly related to osteoporosis. METHODS: A list of all patients between ages 40 and 85 who had been admitted to a tertiary teaching hospital in the last 18 mo with hip fracture or seen in the accident and emergency department with a wrist fracture over the last 30 mo was obtained from computer records; those patients were invited to participate in the audit. In a followup telephone questionnaire, they were queried about potential risk factors for osteoporosis and subsequent fracture, the performance of a BMD test, any information received on osteoporosis and the source of this information, and the prescription of any treatment for osteoporosis. RESULTS: In total, 218 patients were included in the audit from a potential 374 eligible patients. The majority were female (78%), with hip and wrist fractures in 42% and 58%, respectively; 32% subsequently had BMD measured and 39% were offered treatment for osteoporosis. Ninety-four percent of patients had heard of osteoporosis, with the major source of information being the media (83%) and friends (23%), with little information from the medical profession (34%). The major predictors for a patient to have a subsequent BMD test were female sex (OR 3.4, 95% CI 1.3-9.9), history of a previous fracture after the age of 50 (OR 2.3, 95% CI 1.0-5.6), family history of osteoporosis (OR 3.5, 95% CI 1.3-9.5), or the use of concurrent medications with a potential to cause osteoporosis (OR 2.5, 95% CI 1.1-5.8). The main predictors of treatment for osteoporosis being offered were age (risk increased by 1.04 for every year of life), abnormal result on the BMD test (OR 19, 95% CI 6-60), history of fracture after the age of 50 (OR 2.6, 95% CI 1.1-6.7), and a history of fracture with minimal trauma (OR 2.6, 95% CI 1.1-4.2). There was a range of treatments offered, with calcium supplementation alone accounting for 60% of treatments. CONCLUSION: Osteoporosis was overlooked by medical practitioners responsible for the care of this at-risk patient cohort, with little evidence of the medical profession offering information, further investigation, or treatment of patients who presented with a probable osteoporotic fracture of the hip or wrist. This suggests that greater education of the accident and emergency and orthopedic medical staff as well as the general public is required concerning this opportunity to investigate and treat symptomatic osteoporosis.

Adult↗
PubMed2001

Effects of pulse methylprednisolone on macrophage chemotactic protein-1 and macrophage inflammatory protein-1alpha in rheumatoid synovium.

OBJECTIVE: To determine the effect of pulse methyprednisolone (PMP; 1000 mg) on the expression of monocyte chemoattractant protein (MCP)-1 and macrophage inflammatory protein (MIP)-1alpha in rheumatoid synovial membrane. METHODS: Seven patients with rheumatoid arthritis (RA) were studied. Arthroscopically-directed synovial biopsies were taken before and 24 hours after treatment with intravenous PMP. Synovial membranes were stained by immunohistochemical techniques with monoclonal antibodies against MCP-1, MIP-1alpha and CD68 (a macrophage marker). Quantitation of staining was performed by computer-assisted color video image analysis. RESULTS: PMP therapy was associated with a rapid (within 24 hours) and substantial decrease in the expression of MCP-1 and MIP-1alpha expression by a mean of 55% (p = 0.05) and 45% (p = 0.03), respectively, with no effect on CD68 expression in the synovial lining layer. There was no significant change in MCP-1, MIP-1alpha or CD68 expression in the synovial sublining. CONCLUSION: PMP therapy rapidly reduces MCP-1 and MIP-1alpha levels in the synovial lining layer without a fall in macrophage numbers. It thus appears that the initial effect of PMP is that of reducing macrophage activation.

Aged↗
PubMed2001

The TGF beta receptor endoglin in systemic sclerosis.

Immunohistochemical, flow cytometric and ELISA studies were performed to examine the expression of endoglin (CD105, a TGF beta receptor) on dermal endothelial cells, peripheral blood monocytes and free and bound serum levels in patients with systemic sclerosis as compared with appropriate controls. Endoglin was found to be significantly upregulated on dermal blood vessels in patients with scleroderma (and in patients with inflammatory skin disorders) as compared to healthy skin (p < 0.05). In contrast, there was no significant difference in endoglin expression on circulating blood monocytes between scleroderma patients and patients with a rheumatic disoder or healthy control subjects; however, endoglin expression was upregulated on monocytes in inflammatory joint fluid from patients with rheumatoid arthritis. Endoglin expression on monocytes was also influenced by isolation techniques and during whole blood culture. No differences were found in circulating free or bound endoglin levels between scleroderma patients and healthy controls. In conclusion, endoglin expression on dermal endothelial cells was significantly enhanced in scleroderma but levels on circulating monocytes and in the serum were within normal limits. The functional significance of this upregulation is uncertain but may reflect endothelial activation in scleroderma.

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PubMed2000

The development of clinical signs of rheumatoid synovial inflammation is associated with increased synthesis of the chemokine CXCL8 (interleukin-8).

Paired synovial tissue samples were obtained from both clinically uninvolved (CU) and clinically involved (CI) knee joints of eight rheumatoid arthritis (RA) patients. In addition, biopsies were taken from five control subjects. We observed the expression of the chemokines CXCL8, CXCL9, CXCL10, CCL2 and CCL4 in CI and CU joints of RA patients. In particular, CXCL8 protein levels were specifically increased in CI joints compared with CU joints, which was confirmed by immunohistochemistry and in situ hybridization.

Arthritis, Rheumatoid↗
PubMed2000

Quantification of the cell infiltrate in synovial tissue by digital image analysis.

OBJECTIVE: The experience with digital image analysis (DIA) in the assessment of synovial inflammation is limited. In this study we compared DIA with two currently applied methods for the evaluation of the synovium. METHODS: Synovial tissue (ST) specimens were obtained by arthroscopy from knee joints of rheumatoid arthritis (RA) patients with variable disease expression and in control subjects. CD68+ macrophages and CD3+ T-cells were detected by immunohistochemical staining using two different labelling techniques. The labelled ST sections were quantified using three different analysis techniques: manual cell counting (MC), semi-quantitative analysis (SQA) and DIA. RESULTS: We observed strongly positive correlations between the three methods when examining T-cell infiltration: between MC and SQA: sigma=0.91 (P<0. 0001), between MC and DIA: sigma=0.95 (P<0.0001), and between SQA and DIA: sigma=0.83 (P<0.0001). Similarly, for the analysis of synovial intimal macrophages, positive correlations were noted between MC and SQA (sigma=0.62; P=0.002), MC and DIA (sigma=0.56; P<0.01), and SQA and DIA (sigma=0.79; P<0.0001). Finally, the analysis of synovial sublining macrophages revealed positive correlations between MC and SQA (sigma=0.95; P<0.0001), MC and DIA (sigma=0.64; P=0.001) and SQA and DIA (sigma=0.69; P<0.0001). CONCLUSION: These three different methods generated similar results. DIA offers the opportunity of a reliable and time-efficient analysis of the synovial infiltrate.

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PubMed2000

The effects of pulse methylprednisolone on matrix metalloproteinase and tissue inhibitor of metalloproteinase-1 expression in rheumatoid arthritis.

OBJECTIVE: To investigate the effects of a 1000 mg i.v. pulse of methylprednisolone succinate (pulse therapy) on the expression of matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinases-1 (TIMP-1) in the synovial membrane of the knee in patients with rheumatoid arthritis (RA). METHODS: Sequential arthroscopic biopsies of the knee were taken before and 24 h after pulse therapy (11 patients), at disease relapse (three patients) and after retreatment with pulse therapy (one patient). Immunoperoxidase staining for MMP-1 (interstitial collagenase), MMP-3 (stromelysin-1) and TIMP-1 was performed and the immunoreactive staining quantified by colour video image analysis. RESULTS: In the synovial lining layer, MMP-1 and TIMP-1 immunostaining was reduced by a mean of 47% (P = 0.02) and 72% (P = 0.05), respectively, 24 h after pulse methylprednisolone therapy. In the synovial sublining layer, MMP-1 was reduced by a mean of 51% (P = 0.08) and TIMP-1 by a mean of 73% (P = 0.02) 24 h after pulse methylprednisolone therapy. There was no change in MMP-3 staining in the synovial lining or sublining layer. CONCLUSIONS: High-dose pulse methylprednisolone therapy is associated with a rapid (within 24 h) and substantial decrease in the expression of MMP-1 and TIMP-1 but not MMP-3 in the synovial membrane in RA.

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PubMed2000

Evaluation of patient partners in the teaching of the musculoskeletal examination.

OBJECTIVE: To evaluate student preferences and examination outcomes of 2 different methods of teaching musculoskeletal (MSK) medicine examination techniques. METHODS: Year 2 students in a 4 year graduate medical school were randomized to 3 teaching groups: students in Group 1 were taught by rheumatology fellows, Group 2 by patient partners, while group 3 were randomly allocated to either patient partner (3A) or rheumatology trainee (3B) teaching. All students were debriefed at the end of each teaching block of 4 weeks for feedback on their teaching experience using a standardized questionnaire. In addition, at the end of the academic year, all students sat an objective structured clinical examination (OSCE) in clinical skills that contained a rheumatology station. The effect of method of teaching on students' performance in the rheumatology station was analyzed. RESULTS: Eighty medical students participated in the study. Overall, there was no difference in student ratings of either mode of teaching, although the students reported that patient partner teaching gave more opportunity to practice MSK examination skills and also provided greater feedback to the student. Students reported a preference for rheumatology trainee teaching because they believed the teaching would be more relevant to the content of the examination. There was no statistically significant difference in the performance of the students in the OSCE rheumatology station in regard to the mode of teaching they had received prior to the examination. CONCLUSION: Patient partner teaching is as effective a method of teaching clinical skills in MSK medicine as a traditional resident based form of teaching, with student benefits from patient feedback and greater "hands-on" opportunities. The assessment process should incorporate patient partners to assess the unique aspects of patient educator based teaching of MSK examination techniques.

Clinical Competence↗
PubMed1999

Clinical utility of the flow cytometric technique for shared rheumatoid epitope.

The shared rheumatoid epitope (SRE) on the MHC class II antigen-presenting molecule constitutes a probable genetic risk factor for the occurrence of rheumatoid arthritis (RA) and may also determine disease severity. We have used a novel flow cytometric technique to determine the SRE in over 500 predominantly Caucasian patients attending a general rheumatology clinic. This technique has been validated against a polymerase chain reaction (PCR)/SSO molecular method. The SRE was observed in 90% of patients with Felty's syndrome (n = 10) and 75% of patients with RA (n = 178) as compared with 39% of patients with osteoarthritis or non-inflammatory rheumatic disorders (n = 73). Thus, the SRE determined by this method has a sensitivity for RA of 0.75, a specificity of 0.62 and an estimated positive predictive value of 0.02. In our RA cohort, there was no correlation between the functional outcome (health assessment questionnaire score) and SRE status. In conclusion, the determination of the SRE status by a flow cytometric method was found to have only modest sensitivity and specificity for RA; furthermore, the SRE did not correlate with functional outcomes. The clinical utility of the SRE assay is yet to be defined.

Arthritis, Rheumatoid↗
PubMed1999

Shared rheumatoid epitope as a risk factor in determining outcome in rheumatoid arthritis.

BACKGROUND: A genetic component is thought to contribute to 30-40% of the expression of rheumatoid arthritis (RA) with the HLA-DR4, w4 (B1*0401), w14 (B1*0404) genes (and associated shared rheumatoid epitope) constituting a substantial portion of this risk. AIM: Our objective was to determine the presence of these risk factors in a group of patients with RA and to correlate presence with disease outcome. METHOD: Forty-three RA patients who had been regularly assessed up to a ten year period since their initial entry into two gold treatment trials were studied. DR4, w4, w14 and shared rheumatoid epitope were determined on peripheral blood lymphocytes using flow cytometry and specific monoclonal antibodies. Disease outcome was measured by Health Assessment Questionnaire (HAQ) score and C-Reactive Protein (CRP) as a serological measure of joint inflammation. RESULTS: To confirm accuracy of the flow cytometric technique, DR typing and epitope status was compared with results obtained by genotyping in a subset of 14 patients. There was complete concordance between these two techniques for the rheumatoid epitope. However, concordance was not complete (both false positives and false negatives) for DR4, w4 and w14. Hence the presence of rheumatoid epitope was only evaluated further in the larger group. The presence of the shared rheumatoid epitope correlated positively with poorer outcome on serological assessment (p < 0.05). No significant correlation between HAQ score and rheumatoid epitope status was observed although a weak trend was noted. CONCLUSION: These studies suggest that determination of rheumatoid epitope status by flow cytometry may provide useful data concerning the long term outcome of patients with RA.

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