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Biomedical subjects

R M Laxer

Publications and source records attributed to R M Laxer.

At least 73 records · Page 4Linked to original sources
PubMed1994

Arthropathy in thalassaemia patients receiving deferiprone.

The iron chelator deferiprone (L1) reduces tissue iron stores in iron-loaded patients. Three of sixteen patients treated with deferiprone developed joint pain and swelling without evidence of systemic lupus erythematosus (SLE). Articular cartilage, synovial hypertrophy and iron deposition, and synovial lining cell proliferation, with no inflammatory or allergic reaction, were observed on synovial exploration and biopsy. Symptoms resolved partly or completely during continued drug administration. We hypothesise that deferiprone-induced shifts of iron to synovium resulted in tissue damage, accelerated by free-radical formation during incomplete complexation of iron and this bidentate chelator. This deferiprone-associated symptom complex is not associated with drug-induced SLE, and does not progress in severity during continued therapy.

Adolescent↗
PubMed1994

Serum levels of soluble interleukin-2 receptor. A marker of disease activity in localized scleroderma.

OBJECTIVE: To determine whether circulating serum levels of soluble interleukin-2 receptor (sIL-2R) are elevated in patients with localized scleroderma, and if levels of sIL-2R can differentiate between active and inactive disease. METHODS: Seventeen patients with localized scleroderma were categorized by overall physician assessment into active, inactive, and indeterminate groups, according to disease activity. Serum sIL-2R levels were analyzed and correlated with disease activity. RESULTS: The mean sIL-2R level was significantly higher (P = 0.005) in those with active disease (1,675 +/- 823 units/ml) than in those with inactive disease (722 +/- 218 units/ml). CONCLUSION: Serum sIL-2R levels are elevated in patients with localized scleroderma. When present, elevated sIL-2R levels appear to be able to differentiate active from inactive disease. This fact also suggests cell-mediated immune activation in this condition. Further serial studies are required to assess the value and sensitivity of sIL-2R levels in measuring changes in disease activity.

Adolescent↗
PubMed1994

Localized scleroderma in childhood: a report of 30 cases.

Localized scleroderma (LS), a rare disease that occurs primarily in the pediatric age group, differs from systemic sclerosis (SSc) in that it is usually limited to the skin and subcutaneous tissue and is only rarely associated with systemic manifestations. The authors' experience with pediatric LS seen in 30 patients at a tertiary care center was reviewed: 26 had linear scleroderma, 19 on an extremity and 7 on the face; 3 had morphea; and 1 had generalized morphea. Antinuclear antibodies were present in 76% and rheumatoid factor in 39%. Five of 19 patients with linear scleroderma that involved an extremity had growth failure in that limb, and 1 required surgery. Sclerodermatous involvement over a joint resulted in limited range of movement in 6 patients, and 1 required surgery. One of the 30 patients developed SSc and polymyositis. There was difficulty in evaluating disease activity and hence in evaluating treatment. This experience with a large patient population suggests that LS, although usually a self-limiting disease, can result in significant morbidity.

Adolescent↗
PubMed1994

Spontaneous non-traumatic anterior compartment syndrome with peroneal neuropathy and favorable outcome.

We report a girl who spontaneously developed an anterior compartment syndrome with an associated deep peroneal neuropathy. Initial nerve conduction studies (NCS) recorded from the extensor digitorum brevis muscle demonstrated prolongation of the distal latency to 7.8 msec (normal contralateral side, 3.6 msec), and reduction in amplitude of the compound muscle action potential to 0.1 mV (normal contralateral side, 9.9 mV). Electromyography of the tibialis anterior muscle showed an absence of motor unit potentials. Serum creatine kinase was markedly elevated to 12,769 IU. Computed tomography (CT) showed evidence of necrotic muscle. One month later, the foot drop, repeat NCS, and CT demonstrated a significant improvement with conservative management.

Anterior Compartment Syndrome↗
PubMed1994

Local synthesis of both macrophage and T cell cytokines by synovial fluid cells from children with juvenile rheumatoid arthritis.

The production of tumour necrosis factor-alpha (TNF-alpha), TNF-beta and IL-6 in synovial fluid was studied in 50 samples of synovial fluid from 44 children with juvenile rheumatoid arthritis (JRA) by identifying cytokine production at a single-cell level. Post Ficoll-separated synovial fluid mononuclear cells were permeabilized and then intracellular TNF-alpha, TNF-beta and IL-6 protein production was examined using indirect immunofluorescence and murine anti-cytokine MoAbs. All three cytokines were measured in 37 of the 50 samples. In 25 of the 37 samples there was complete concordance; all three cytokines were present in six and absent in 19 samples. At least one cytokine was present in 27/50 (54%) of synovial fluid samples. Overall, TNF-alpha was detected in 22/49 (45%) samples, TNF-beta in 15/41 (37%) and IL-6 in 16/45 (36%) samples. Five patients had serial arthrocentesis, and in these samples there were two patients who had initially positive cytokine production, which on subsequent measurement was negative; in the other three patients there was no change from the previous cytokine production. We provide evidence that synovial fluid mononuclear cells produce monocyte and T cell cytokines in JRA. These findings suggest a role for both T cell and macrophage products in the pathogenesis of JRA, and the potential for modulation of cytokine production as a target for therapeutic intervention.

Adolescent↗
PubMed1994

Intravenous immunoglobulin in the treatment of systemic juvenile rheumatoid arthritis: a randomized placebo controlled trial. Pediatric Rheumatology Collaborative Study Group.

OBJECTIVE: To assess the efficacy and safety of intravenous immunoglobulin (IVIG) in juvenile rheumatoid arthritis (JRA). METHODS: Thirty-one children with active, refractory, systemic JRA were randomized into a multicentered, double blinded, placebo controlled trial. Patients received infusions of 1.5 g/kg of IVIG or placebo (0.1% albumin) every 2 weeks for 2 months, then monthly for 4 months (total: up to 9 infusions over 6 months). Twenty-nine of the 31 patients were included in the efficacy subset. RESULTS: Fourteen patients discontinued prematurely from study, 7 in each treatment group. A higher proportion of patients in the IVIG group improved (50 vs 27%) as assessed by the physician's global assessment. However, the sample size was small and this difference was not statistically significant. IVIG was not more effective than placebo in reducing the number of days with fever or other systemic manifestations. Changes from baseline in the joint count, hemoglobin, albumin, platelet count, and erythrocyte sedimentation rate did not differ between treatment groups. CONCLUSION: Our results suggest that high dose IVIG has limited clinical utility in systemic JRA. However, this trial failed to enroll adequate numbers of patients to permit valid statistical intergroup comparisons, and the results must be considered nondefinitive.

Adolescent↗
PubMed1994

Phospholipase A2 in juvenile rheumatoid arthritis: correlation to disease type and activity.

OBJECTIVE: Secretory nonpancreatic phospholipase A2 (snpPLA2) is a proinflammatory enzyme and its activity in serum correlates with disease activity in adults with rheumatoid arthritis. Juvenile rheumatoid arthritis (JRA) may be stratified into 3 clinical types with differing degrees of disease activity. Since in JRA there are no reliable indices of disease activity, our objective was to find whether the level of circulating snpPLA2 correlates with the severity of inflammation and with JRA activity. METHODS: PLA2 enzymatic activity was assayed using E. coli membranes labelled with (14C)-oleic acid. SnpPLA2 immunoreactivity was tested by ELISA technique using monoclonal antibodies against recombinant human (rh) snpPLA2. SnpPLA2 activity was determined in sera of 127 children including 25 with systemic (S-JRA), 50 with polyarticular (Po-JRA) and 52 with pauciarticular (Pa-JRA) types of JRA. Twenty-five patients with active disease, were subsequently restudied in an inactive phase. RESULTS: Markedly increased snpPLA2 (> mean + 2 SD of normal mean, i.e., > 575 U/ml) was found during the active disease in 100% S-JRA, 57% Po-JRA and 25% Pa-JRA patients. The differences in the mean and median PLA2 activity among these 3 subtypes of JRA were highly significant (p < 0.001) with the highest levels found in S-JRA and the lowest in Pa-JRA. Presence of rheumatoid factor and/or of antinuclear antibody had no relation to the level of snpPLA2. SnpPLA2 activity became markedly lower when active inflammation became quiescent. In the whole group, snpPLA2 activity correlated highly with the Lansbury index, number of involved joints and number of effusions. A significant positive correlation was also found between snpPLA2 and erythrocyte sedimentation rate (ESR) and neutrophil count, while a significant negative correlation was noted with the level of albumin and hemoglobin. With the exception of snpPLA2, other laboratory variables did not correlate with the number of effusions or the number of active joints. However a negative correlation was noted between both hemoglobin and albumin, and Lansbury index. CONCLUSION: Circulating snpPLA2 significantly correlates with JRA activity and may serve as an index of activity in JRA especially in patients with systemic type of disease.

Adolescent↗
PubMed1993

Localized scleroderma progressing to systemic disease. Case report and review of the literature.

We describe a 15-year-old girl with biopsy-proven morphea who developed progression to systemic disease 2 years after initial presentation. In contrast to other reported patients with localized scleroderma, some of whom have had mild, nonprogressive systemic involvement, this patient developed severe, debilitating disease, with skin tightness, sclerodactyly, esophageal involvement, restrictive pulmonary disease, and myopathy. From the time of her initial evaluation, the patient was positive for antinuclear antibodies (ANA), which were shown to be primarily directed against the Ku antigens. This observation suggests that ANA may be a prognostic indicator for progression to systemic disease.

Antibodies, Antinuclear↗
PubMed1993

Diagnostic use of B-cell alloantigen D8/17 in rheumatic chorea.

Two unrelated patients with a family history of rheumatic fever had isolated, acquired chorea. Both index cases, as well as affected family members, had increased expression of the rheumatic B-cell alloantigen D8/17. This test may help differentiate Sydenham chorea from lupus chorea.

B-Lymphocytes↗
PubMed1993

Synovial fluid cells in juvenile arthritis: evidence of selective T cell migration to inflamed tissue.

The perpetuation of chronic synovitis in juvenile arthritis (JA) is a complex interaction of local and systemic regulatory mechanism. We examined the cell surface phenotype of synovial fluid cells and peripheral blood lymphocytes from 15 patients with JA to better understand the mechanism of local inflammation. Synovial fluid and peripheral blood mononuclear cells were analysed for cell surface expression of CD2, CD3, CD4, CD8, CD19, CD25, CD29, CD45R and Ia using flow cytometry. We found a very low percentage of B cells with a concomitant increase of T cells in synovial fluid as compared with peripheral blood. A large percentage of the synovial fluid T cells were HLA-DR+, or activated T cells, and there was a relative decrease in CD4+ cells in synovial fluid as compared with peripheral blood. There was only a minimal increase in CD25+ synovial fluid cells. The synovial fluid CD4+ cells were mainly of the CD2high, CD29+, CD45RO phenotype. This CD4 phenotype found on synovial fluid cells from patients with JA and in particular the CD29 cell surface marker, which recognizes a common beta-chain of adhesion molecules, is associated with binding to extracellular matrix proteins and is also associated with 'primed' T cells. Our results demonstrated the presence of T cells which either selectively migrate to synovium and synovial fluid or are activated in situ in the joint.

Adolescent↗
PubMed1992

Evidence for clonal expansion of T cell receptor V gamma II+ T cells in the synovial fluid of patients with arthritis.

We have demonstrated among synovial fluid T cells a unique profile of V gamma II sequences likely arising from clonally expanded T cells. We have determined the junctional diversity associated with each expressed V gamma family by resolving amplified fragments of cDNA into component parts on large denaturing gels. Among synovial fluid T cells we frequently find dominant fragments of a unique size clearly smaller than the dominant band observed with peripheral blood T lymphocytes. In some cases the dominant bands are 12 or 15 nucleotides smaller than the corresponding most abundant band from peripheral blood T lymphocytes. Patterns of lower m.w. species not typical of a polyclonal population argues that clones of T cells expressing the V gamma II family are expanding in the joint and that a high proportion of these cells do not express the V gamma IIJP sequence typical of peripheral blood but rather express V gamma II in combination with a shorter J fragment, JP1, JP2, J1, or J2. In addition by examining joint effusions from the left and right knees from the same individual we have shown that the profiles of V gamma II sequences derived from the fluids are identical to each other but clearly distinct from that of peripheral blood. We have, in addition, quantitated with a series of synthetic internal standards the relative usage of each V gamma family expressed by T cells in the synovial fluid and peripheral blood of seven patients with arthritis including six patients who were either children or adolescents and one adult patient. All patients showed a reduction in the relative expression of V gamma II in synovial T cells relative to peripheral blood T lymphocytes and a corresponding increase in the expression of V gamma I or V gamma III or both. We did not detect expression of V gamma IV in either lymphocyte population.

Arthritis↗
PubMed1992

Prognostic indicators of joint destruction in systemic-onset juvenile rheumatoid arthritis.

We retrospectively reviewed the charts and radiographs of 38 patients with systemic-onset juvenile rheumatoid arthritis, attempting to identify early in the disease course the clinical and laboratory observations most predictive of the later development of destructive arthritis. In 12 of the patients, destructive arthritis developed within 2 years of disease onset. When first examined, these patients could not readily be differentiated from those in whom joint destruction did not develop, but they more commonly had hepatosplenomegaly (p less than 0.04), serositis (p less than 0.01), and a lower mean serum albumin concentration (26.7 vs 31.3 gm/L; p less than 0.02). However, by 6 months after onset, patients with destructive arthritis more frequently had persistent systemic symptoms (92% vs 12%; p less than 0.0001), polyarthritis (67% vs 19%; p less than 0.0005), a lower mean hemoglobin level (95 vs 114 gm/L; p less than 0.001), a higher mean leukocyte count (21.2 vs 10 x 10(9)/L; p less than 0.0003), a higher mean platelet count (794 vs 400 x 10(9)/L; p less than 0.0001), and a higher mean erythrocyte sedimentation rate (43 vs 24 mm/hr; p less than 0.05). Multivariate analysis of the results at 6 months revealed that persistent systemic symptoms and a platelet count greater than or equal to 600 x 10(9)/L were the variables most highly predictive of the later development of joint destruction. We conclude that patients at high risk for the development of destructive arthritis may be identified within 6 months of disease onset, thereby indicating the need for more aggressive early therapy.

Adolescent↗
PubMed1992

High synovial immunoglobulin E levels in eosinophilic synovitis.

Eosinophilic synovitis occurred in a 7-year-old boy. Synovial fluid leukocytes were mostly eosinophils; the peripheral blood showed only mild eosinophilia. The level of eosinophil-derived neurotoxin in the synovial fluid was higher than that in the serum, suggesting intraarticular eosinophil degranulation. The IgE level was also elevated in the synovial fluid (3854 ng/ml) but normal in the serum (408 ng/ml), suggesting a localized immediate hypersensitivity immune response.

Child↗
PubMed1992

Childhood linear scleroderma: a possible role of thermography for evaluation.

Linear scleroderma is a rare, at times debilitating, disease with an unpredictable course. Currently, there is no satisfactory objective method for assessment of disease activity upon which to base therapeutic decisions. We evaluated 11 children with 18 linear scleroderma lesions (mean age 11.7 years, mean duration of disease 5.1 years) for disease severity and the presence of immunologic abnormalities, and attempted to correlate these results with thermography. Positive thermography was defined as warmer than surrounding skin or opposite limb by 0.5 degrees C. Six patients were thermography positive. Mean age, sex, disease duration and the presence of hypergammaglobulinemia and autoantibodies were similar in thermography positive and thermography negative patients. Six of 18 linear scleroderma lesions were thermography positive. All 3 new or expanding lesions were thermography positive. All 3 lesions that were resolving clinically were thermography negative. Three of 12 lesions that were clinically unchanged over a 6-month period were also thermography positive. In summary, thermography is a noninvasive test that appears to demonstrate active lesions in linear scleroderma. It is not influenced by previous soft tissue damage induced by linear scleroderma and may enable better monitoring of the effectiveness of proposed therapies.

Adolescent↗
PubMed1992

T cell receptor V beta usage in synovial fluid of children with arthritis.

We have examined synovial fluid (SF) T cells from 5 children with various types of juvenile arthritis. Using the polymerase chain reaction (PCR) to determine the expression of 20 individual T cell receptor (TCR) beta variable (V) region families, we have shown with each patient that the SF T cells are polyclonal. Nevertheless, expanded usage of some families by SF T cells relative to peripheral blood T cells was evident in some cases. We conclude that the pattern of T lymphocytes in the inflamed joint may be a consequence in part of a polyclonal expansion or nonspecific homing of T cells to the joint, and in part a more restricted expansion of T cells potentially driven by arthritogenic antigens.

Antibodies, Antinuclear↗
PubMed1991

Primary pulmonary hypertension in a patient with systemic-onset juvenile arthritis.

We describe a 16-year-old girl with systemic-onset juvenile arthritis who presented with pulmonary hypertension, without evidence of pleural or parenchymal involvement of the lung, pulmonary vasculitis, or immune deposition in the pulmonary vasculature. Pleuropulmonary involvement occurs occasionally in juvenile arthritis, but primary pulmonary hypertension has not, to our knowledge, been previously reported. Histocompatibility typing showed positivity for HLA-DR3 and DRw52, both of which are associated with idiopathic pulmonary hypertension in children, and with pulmonary hypertension among patients with systemic sclerosis. Treatment with cyclosporine and corticosteroids resulted in a marked improvement in the clinical findings and pulmonary function in our patient.

Adolescent↗
PubMed1991

Wegener's granulomatosis in childhood.

The authors reviewed the medical histories and radiological examinations of five pediatric patients with a histologic diagnosis of Wegener's granulomatosis (WG) seen over a six year period in whom a total of 22 thoracic CT scans were performed. Involvement of both the upper and lower respiratory tracts was seen in all patients at presentation. One patient had subglottic stenosis necessitating tracheotomy. Pulmonary hemorrhage occurred in three patients at initial diagnosis. Classic cavitary lung nodules were seen in two patients--one at initial presentation, the other at relapse. The plain radiographic lower respiratory tract manifestations of pediatric WG were protean both at initial presentation and during follow up. Similarly, disease expression was highly variable on thoracic CT examinations but, overall, multifocal parenchymal infiltrates with or without small peripheral nodules were the commonest thoracic CT manifestations. As a consequence of cytotoxic and corticosteroid therapy the long-term prognosis of WG has improved considerably in recent years. Knowledge of the varied patterns of the primary disease and potential for iatrogenic complications are necessary for successful radiologic assessment of pediatric patients with WG.

Adolescent↗