Anti-vascular endothelial cell antibodies (AECA): comparison of two assay methods and clinical applications.

Vascular endothelial cells may be a target for autoantibodies (AECAs) against membrane antigens that are constitutively expressed, induced or bound to their surface. To test this hypothesis, we used an enzyme-linked immunosorbent assay (ELISA) with two types of human endothelial cells as the substrate, i.e., human umbilical cord vein endothelial cells (HUVECs) or the hybrid cell line EAhy-926 obtained by fusion of HUVECs with the bronchial carcinoma cell line A549. A comparative functional study of these two cell types demonstrated that EAhy-926 cells produced only small amounts of VIII von Willebrand factor and tissular factor, did not contain Weibel Palade bodies visible under the electron microscope, and expressed ICAM-1 and selectin E in levels of no more than 15% of those expressed by human umbilical cord vein endothelial cells both after stimulation by bacterial lipopolysaccharide and under basal conditions. However, the two assay methods yielded similar IgG AECA titers when used on sera from patients with rheumatoid vasculitis or antiphospholipid syndrome. These antibodies did not exhibit cytotoxicity for cord vein or EAhy-926 cells. They were not specific for endothelium, since their activity decreased by a mean of 40% after incubation of sera with the epithelial cell line A549. A cross-sectional study of 565 sera demonstrated that anti-vascular IgG and IgM AECAs reactive with EAhy-926 cells occurred mainly in patients with dermatomyositis (IgG, 58%; IgM, 22%), systemic scleroderma (IgG, 48%; IgM, 18%), primary Sjögren's syndrome (IgG, 44%; IgM, 12%) and secondary and primary systemic vasculitides (IgG, 38%; IgM, 18%) including Wegener's granulomatosis. A longitudinal study in patients with Wegener's granulomatosis showed that AECAS were predictive of disease activity.

[Osteoarthritis with rice bodies rich in calcium microcrystals. 4 cases with ultrastructural study]. / Arthropathies mécaniques avec grains de riz riches en microcristaux calciques. Quatre cas avec étude ultrastructurale.

Rice bodies are often found in inflammatory joint fluid specimens, especially from rheumatoid arthritis patients, but have rarely been reported in osteoarthritis. We found rice bodies in knee joint fluid specimens from four of 88 patients with osteoarthritis. There were three males and one female. Age ranged from 61 to 86 years. Three patients had slowly progressive knee osteoarthritis and one had rapidly destructive disease. Abundant, recurrent effusions occurred in all four patients despite one to five local corticosteroid injections per patient and radiation synovectomy in two patients. The joint fluid specimens contained 120 to 320 cells/mm3 and large numbers of rice bodies that stained with alizarin red S. Transmission electron microscopy studies showed that the rice bodies were composed of fibrin and contained numerous intra- and extra-cellular calcium crystals composed of apatite alone in two cases and of a combination of apatite and calcium pyrophosphate dihydrate in the two others. Collagen fibers and fragments of bone and cartilage were present in a few rice bodies. Phagocytic cells, type C synoviocytes, chondrocytes and a few inflammatory cells were also seen. These rice bodies composed mainly of fibrin and apatite may have played a role in the pathogenesis of the recurrent joint effusions in our patients.

Paradiaphyseal calcific tendinitis with cortical bone erosion.

OBJECTIVE: To determine the clinical, radiologic, and histologic features of calcific tendinitis with cortical bone erosion. METHODS: The records of 6 patients with paradiaphyseal calcific tendinitis and adjacent bone cortex erosion were reviewed. RESULTS: Calcific tendinitis involved the linea aspera in 4 patients, the bicipital groove in 1 patient, and the deltoid insertion in another. Calcium deposits were associated with cortical bone erosions, revealed on plain radiographs in 4 patients and computed tomography scans in 2. Bone scans were performed in 2 patients and showed local hyperfixation of the isotope. In 4 patients, suspicion of a neoplasm led to a biopsy. Calcium deposits appeared to be surrounded by a foreign body reaction with numerous giant cells. Apatite crystals were identified by transmission electron microscopy and elemental analysis in 1 surgical sample. CONCLUSION: Paradiaphyseal calcific tendinitis with cortical bone erosion is an uncommon presentation of apatite deposition disease.

[Alizarin red staining of articular fluids. Comparison of the results with electron microscopy and clinical data]. / Coloration par le rouge alizarine des liquides articulaires. Confrontation des résultats avec ceux de la microscopie électronique et avec les données cliniques.

Coloration of articular fluids with alizarin S red has been proposed as a method of sensitive detection of calcium microcrystals, especially apatite crystals. We are reporting the results of a study of 230 non-selected fluids. The results of the coloration were quantified into negative, slightly positive, moderately positive and strongly positive. Study of X-Rays of the tapped joint and of the hospital file was done in 199 patients. Electron microscope study, of 44 fluid samples, shows that the coloration with alizarin red permits a reliable detection of calcium microcrystals in the articular fluid, only if the strongly positive results are taken into account. But the coloration is not specific for apatite: 5 strongly positive fluids out of 14 contain only, in electron microscopy, crystals of dihydrated calcium pyrophosphate. 10.8% of the stained fluids give a strongly positive result. In two cases, it concerns destructive arthropathies of the shoulder with periarticular calcifications. The other strongly positive results are found in chondrocalcinosis (52 p. cent), in arthrosis (17 p. cent) and in rheumatoid polyarthritis (15 p. cent). As a whole, the results are correlated with age and the degree of radiological destruction. The similar percentage of strongly positive fluids observed in arthrosis and rheumatoid polyarthritis, is not in favor of a specific role of apatite microcrystals in the pathogenesis of arthrosis. Since the majority of strongly positive fluids come from joints which are very destroyed, regardless of the arthropathy concerned (rheumatoid polyarthritis, chondrocalcinosis or arthrosis), it is possible to think that it is mostly the destruction of the sub-chondral bone which explains these results.

[Destructive spondylarthropathy with amyloid deposits in 3 patients on chronic hemodialysis]. / Spondylarthropathie destructrice avec dépôts amyloïdes chez 3 patients en hémodialyse chronique.

Destructive spondyloarthropathy is a recently described complication of chronic hemodialysis. Three patients presenting spondyloarthropathy with destructive discovertebral lesions of the cervical or lumbar sections of the spine underwent surgery due to neurologic complications: persistent radiculalgia (two cases), regressive tetraparesis (one case). Discal lesions were associated with dislocation of the posterior intervertebral articulations and slipping of vertebrae. These patients had been receiving chronic hemodialysis for more than ten years; two presented hyperparathyroidism and blood aluminum was markedly increased in all cases. Two patients had undergone surgery for bilateral carpal tunnel syndrome. Anatomopathological examination of surgical specimens demonstrated the presence of amyloid deposits in the intervertebral disc. This suggests that amyloidosis, which is frequently seen with carpal tunnel syndrome in patients receiving prolonged hemodialysis, also plays a role in the development of spondyloarthropathy.

Synovial amyloidosis in patients undergoing long-term hemodialysis.

Synovial amyloid deposits were found in 18 patients with end-stage renal failure due to various nonamyloid nephropathies, who had been treated with long-term, periodic hemodialysis (mean 116 months). All patients had carpal tunnel syndrome, which was bilateral in 14 of them; 4 patients also had finger flexor tenosynovitis. In 2 patients, destructive arthropathies required surgical replacement of the hip. Amyloid deposits were demonstrated by light microscopy in the synovium of the finger flexor tendon and/or transverse carpal ligament of all patients who had surgery for carpal tunnel syndrome, and in the synovium and capsula of the 2 surgically removed hips. Transmission electron microscopy of synovial samples from 6 patients demonstrated the characteristic fibrillar ultrastructure of amyloid deposits, the biochemical nature of which is still unknown. In addition, 9 patients had cystic radiolucencies of bone, which were interpreted as having resulted from local amyloid deposits, involving carpal bones, humeral heads, femoral heads, acetabula, or tibial plateaus. Our results show that amyloidosis is a frequent histologic finding in dialysis patients receiving surgical management of carpal tunnel syndrome, and that it can also be associated with cystic radiolucencies of bones and with destructive arthropathies.

Osteoclast abnormalities in idiopathic osteopetrosis. Reference to the ultrastructural histochemistry study.

In order to investigate skeletal abnormalities in a case of idiopathic osteopetrosis, a bone biopsy was taken from the anterior iliac crest and prepared for ultrastructural and histochemical study. There was a drastic reduction in osteoclastic bone resorption. The ruffle border and sealing zone, which are the osteoclast cell surface markers of bone resorption, were absent. The cells were highly vacuolated, and the vacuoles contained large amounts of a residual organic material which reacted strongly with acid phosphatase. Acid phosphatase activity was never found outside the cell, and in particular, not at the bone-cell interface. This suggests that the defect in bone resorption is caused by cell membrane abnormalities and the lack of ruffle border formation, rather than the inability of the lysosomal enzymes to digest the bone matrix.

Transmission electron microscopic identification of silicon-containing particles in synovial fluid: potential confusion with calcium pyrophosphate dihydrate and apatite crystals.

Silicon-containing particles were identified by transmission electron microscopy (TEM) in thin sections of two synovial fluids, which also contained calcium pyrophosphate dihydrate (CPPD) crystals, aspirated during acute attacks of pseudogout. Such particles, which are interpreted as probably being artefacts from glassware, were electron dense and similar in appearance to some CPPD or hydroxyapatite crystals.

Tumoral calcinosis: light and electron microscopic study with electron diffraction and x-ray microanalysis of the mineral deposit.

Samples of deposits taken from sites close to articulations in a young black African suffering from tumoral calcinosis with hyperphosphoraemia were studied by light and electron microscopy techniques. Light microscopy demonstrated lesions of a foreign body granuloma type in contact with calcium salt deposits suggesting that the process was of an active nature. Electron microscopy, and the demonstration of acid phosphatase activity, led to the identification of two cell types: mono or multinuclear macrophage type cells which phagocytose the deposit, and fibroblastic type cells. No signs of damage to the microvessels or the interstitial collagen were noted which could serve as a basis or a physiopathological explanation of the deposition. The deposits were analysed by energy dispersive X-ray microanalysis and by electron diffraction and were considered to be hydroxyapatite.

[Changes in vascular endothelial cells induced by serum from scleroderma and other connective tissue diseases]. / Altérations des cellules endothéliales vasculaires induites par les sérums de sclérodermie et d'autres connectivites.

The growth inhibition of in vitro vascular endothelial cell cultures by sera from patients with connective tissue disease was studied. Seven out of 30 sera from patients with progressive systemic sclerosis (PSS) exhibited a cytotoxic effect. The cytotoxic serum factor(s) was not specific to patients with symptoms (11 out of 27 sera from patients with a mixed connective tissue disease, MCTD; 5 out of 34 sera from patients with a systemic lupus erythematosus, SLE). The cytotoxic effect was not specific for vascular endothelial cells, it was also found on fibroblast cells cultures. Inhibitor(s) of cell growth in vitro was independent of antinuclear and anticytoplasmic antibodies and appeared as a common feature of all connective tissue disease with vascular symptoms.

A study of microvasculature in normal and inflammatory synovial membranes in the rabbit using light and electron microscopy and freeze fracture.

The Authors made a study of microvasculature in normal and inflammatory synovial membranes in the rabbit, by light and electron microscopy and with the use of freeze fracture. The synovial membrane of the knee was studied in 15 normal rabbits and in 22 rabbits in whom immunization with mycobacterium tuberculosis crude cytoplasmic water soluble extract had provoked inflammatory synovitis. A comparison between normal and inflammatory synovia by light microscopy showed, in inflammatory synovitis, a significant increase in the number of congested and obliterated microvessels (p less than 0.001) and in the number of endothelial nuclei per microvessel (p less than 0.0001). By electron microscopy no specific alteration of synovial microvessels was observed. A significant increase was found in the number of venules in inflammatory synovitis (p less than 0.01). The number of simple interendothelial tight junctions, defined by 1 or 2 interendothelial contacts, and of complex interendothelial tight junctions, defined by 3 or more interendothelial contacts, was similar in venules and in capillaries of inflammatory synovitis and of normal controls. The mean number and mean spacing of junctional strands in interendothelial tight junctions was similar in the microvessels of inflammatory synovitis and of normal controls. The Authors conclude that inflammation does not provoke specific alterations in synovial microvasculature but could induce an adaptative state resulting in increased synovial permeability.

[Hemopigmented villonodular synovitis: ultrastructural study and a comparison with hemophiliac synovitis]. / Synovite villonodulaire hémopigmentée. Etude ultrastructurale et comparaison avec la synovite hémophilique.

In a study of the ultrastructure of two cases of villonodular synovitis and two cases of haemophiliac synovitis, the authors observed very similar lesions. In both diseases, the lesions of the superficial layer of the synovium consisted of intermediate type (type C) synoviocytes loaded with iron pigments or lipid vacuoles. In the deep layer, the authors observed numerous macrophages loaded with siderosomes, lipid inclusions or phagocytosed red blood cells, giant cells and capillaries with a thickened basement membrane with a layered appearance. The cytoplasmic membranes of the synoviocytes were joined by desmosomes or filopodal digitations. The similarity of the lesions in the two diseases suggests a common histogenetic mechanism for the synovial lesions: chronic haemarthrosis.

Vascular endothelial cell injury in progressive systemic sclerosis and other connective tissue diseases.

The growth inhibition of in vitro vascular endothelial cell cultures by sera from patients with connective tissue diseases was studied. Seven out of 30 sera from patients with progressive systemic sclerosis (PSS) exhibited a cytotoxic effect. The cytotoxic serum factor(s) was not specific to patients with PSS, it was also demonstrated in sera from patients with other connective tissue diseases with vascular symptoms (11 out of 27 sera from patients with a mixed connective tissue disease, MCTD; 5 out of 34 sera from patients with a systemic lupus erythematosus, SLE). The cytotoxic effect was not specific for vascular endothelial cells, it was also found on fibroblast cells cultures. Inhibitor(s) of cell growth in vitro was independent of antinuclear and anticytoplasmic antibodies and appeared as a common feature of all connective tissue diseases with vascular symptoms.

[Synovial vascularization and inflammation. II. Electron microscopy study of capillary permeability using immunoperoxidase]. / Vascularisation synoviale et inflammation. II.--Etude en microscopie électronique de la perméabilité capillaire par l'immunoperoxydase.

The distribution of IgG and IgM into the normal and rheumatoid synovial membrane have been studied by the authors by means of immunoperoxidase electron-microscopy. Within the normal synovial while the IgG are diffusing out of the capillary the IgG are kept in the vascular lumen. Within the rheumatoid synovia IgG and IgM widely diffuse out of the microvasculature. This finding suggest that the rheumatoid inflammation is raising the permeability of synovial capillaries towards IgM molecules.

Relapsing polychondritis. An ultrastructural study of elastic and collagen fibres degradation revealed by tannic acid.

In a case of relapsing polychondritis, ultrastructural study of ear cartilage using tannic acid staining showed patterns of degradation of elastic and collagen fibres. The participation of macrophages and chondrocytes in the resorption of ear cartilage is discussed.

[Synovial vascularization and inflammation. I. Morphologic study using light and electron microscopy]. / Vascularisation synoviale et inflammation. I. Etude morphologique en microscopie optique et électronique.

The authors studied using light and electron microscopy, 40 cases of sub-acute inflammatory synovitis (including 24 cases of rheumatoid synovitis) and 10 normal synovia. In light microscopy, the study dealt with images of capillary congestion, endothelial hyperplasis and capillary obliterations. In electron microscopy the morphology of the capillaries, the images of plasmic exsudation, images of extravascular cell migration and vascular obliteration by the endothelial cells, were studied in comparison with the inflammatory synovitis and the normal synovia. Inflammatory synovitis are characterized by the frequency of extracapillary cell migrations without there being any other pathological change of the microvessels that can be attributed to inflammation.

Cellular junctions in normal and inflammatory human synovial membrane revealed by tannic acid and freeze fracture.

Cellular junctions between synovial cells and endothelial cells of the microvasculature were examined in 10 normal and 20 inflammatory human synovial membranes by means of tannic acid and freeze fracture, Gap junctions and desmosomes predominated on synovial cells, and tight junctions in the microvasculature. Comparison between normal and inflammatory synovial membranes did not demonstrate changes in cellular contacts that might be caused by inflammation.

Light and electron microscopy study of capillaries in normal and inflammatory human synovial membrane.

Synovium aspirated from the knee joint by trochar was studied by light and electron microscopy in 40 cases of inflammatory arthritis and in 10 controls. The morphology of synovial capillaries, extravascular plasma diffusion, interendothelial vascular gaps, extracapillary blood cell migration, vascular congestion, endothelial hyperplasia, and obliteration of the capillary lumen by endothelial cells were compared in normal and inflammatory synovia. Inflammatory synovitis was characterised by the number and diversity of blood cells migrating through the interendothelial pathway out of the capillary lumen. Polymorphonuclear leucocytes were the blood cells most often seen at interendothelial junctions. No other capillary changes that might be related to synovial inflammation were found.

Ultrastructural study of human synovial membrane with immunoperoxidase.

An ultrastructural immunoperoxidase study of human synovial membrane biopsies performed in 16 patients with rheumatoid synovitis and in 14 control patients showed that: (1) plasma immunoglobulins have an intercellular distribution and seem to diffuse mainly by an intercellular rather than by a transcellular pathway; and (2) there is a difference in the distribution of plasma IgG and IgM. IgG was found in intravascular and extravascular spaces in all biopsies. IgM was found only in intravascular spaces in control biopsies, but in rheumatoid synovitis it was present in both intravascular and extravascular spaces. This difference in distribution may be due to increased vascular permeability in inflammatory synovitis.