In vitro cytotoxicity of human endothelial cells in polymyalgia rheumatica and giant cell arteritis

Current concepts in giant cell (temporal) arteritis

Giant cell (temporal) arteritis continues to be a sight-threatening, systemic vasculitis with a poorly understood pathogenesis. The characteristic granulomatous inflammation of the vessel wall commonly leads to local ischemia. Recent advances in immunological investigations have characterized the cellular components of the disease process, but the etiology has so far remained unresolved. A reappraisal of the clinical features of giant cell (temporal) arteritis demonstrates the heterogeneity of the manifestations of the disease, including ischemic optic neuropathy. A range of new laboratory investigations and blood flow studies with color Doppler imaging have demonstrated promising roles, with respect to diagnosis and long-term follow-up. Prompt diagnosis and expeditious treatment require a high index of clinical suspicion, particularly for atypical cases. Corticosteroids remain the treatment of choice, other immuno-suppressive agents being used as second line steroid-sparing agents. Giant cell (temporal) arteritis leads to increased vascular and visual morbidity and, if untreated, may prove fatal. To maintain high standards of management of this enigmatic disorder, ophthalmologists need to be aware of the clinical spectrum of giant cell (temporal) arteritis and currently available diagnostic tests and treatment strategies.

Polymyalgia rheumatica. Clinical features and management

Polymyalgia rheumatica is a clinical syndrome that occurs almost exclusively in older patients. It is characterized by muscle aching and stiffness and an elevated erythrocyte sedimentation rate. It must be distinguished from other common disorders, particularly polymyositis, fibromyalgia, and other chronic inflammatory or neoplastic diseases. A temporal artery biopsy should be done in patients with confirmed polymyalgia rheumatica and suspected coexistent temporal arteritis, which can have serious manifestations. Patients with polymyalgia rheumatica respond dramatically to low doses of corticosteroids, although prolonged daily treatment often may be needed.

The effects of scleroderma serum on human microvascular endothelial cells. Induction of antibody-dependent cellular cytotoxicity

To investigate the vascular immunopathology of systemic sclerosis, we developed a model consisting of human microvascular endothelial cells, leukocytes, and serum. Sera from 19% of the patients studied mediated antibody-dependent cellular cytotoxicity against endothelial cells. Some sera also mediated cytotoxicity against aortic endothelium and fibroblasts. K lymphocytes, the cells that mediate antibody-dependent cellular cytotoxicity, were identified in the skin of some patients. The sera alone were not cytotoxic or growth inhibitory, and did not affect endothelial prostacyclin production.

[Physiopathologic bases of the treatment of systemic scleroderma]

Numerous drugs have been suggested for the treatment of systemic scleroderma. They may be studied and classified according to their site of action on the chain of events that leads from vascular abnormalities to sclerosis of the skin. Thus, proline analogues, colchicine, lathyrogenic agents, D-penicillamine, coagulation factor XIII and oestrogens are thought to act on collagens and their metabolism. Ketanserin has been suggested by the discovery of tryptophan abnormalities. Corticosteroids exert an inhibitory effect on fibroblasts. The use of calcium antagonists, angiotensin-converting enzyme inhibitors, prostacyclin and anti-platelets rests on the presence of vascular abnormalities. The purpose of treatments with immunosuppressive drugs or plasma exchanges is to act on possible lymphocytic and/or macropageal factors.

An assay for estimating the cytotoxicity of synovial fluid from patients with rheumatoid arthritis

The joint is the prime site of involvement in rheumatoid arthritis: the synovium showing lymphocytic involvement and damage. The synovial fluid shows evidence of inflammation such as increased neutrophils and raised CRP. Application of a cell-free extract of serum or synovial fluid from patients with rheumatoid arthritis, or serum from normal individuals on to 111indium oxine radiolabelled endothelial cells and fibroblasts, promotes the release of the isotope as a result of cell damage and death (cytotoxicity). In paired samples, synovial fluid was consistently more cytotoxic than rheumatoid serum. There was no difference in the cytotoxicity of rheumatoid serum or normal serum. These results demonstrate the presence of soluble factors in synovial fluid, which are capable of destroying cells, typical of those found in the synovial cavity, in blood vessels and in connective tissue generally. This system may prove to be a useful model of inflammatory damage.

Endothelial cell cytotoxicity in inflammatory vascular diseases--the possible role of oxidised lipoproteins

One of the proposed mechanisms of vascular damage in connective tissue disease is the direct action of a cytotoxic serum factor inducing endothelial cell damage. The nature of this serum factor is unclear, but has been suggested to be a lipoprotein. Sera from patients with (1) systemic necrotising arteritis (polyarteritis nodosa, Wegener's granulomatosis, and necrotising arteritis associated with rheumatoid synovitis), (2) systemic or joint restricted rheumatoid disease, and (3) large vessel/giant cell arteritis have been examined for cytotoxicity to human cultured endothelial cells and azide-resistant ferroxidase-like activity (indicative of the oxidised lipoprotein content). Stored sera from patients with necrotising arteritis showed a significantly enhanced tendency to develop oxidised lipoprotein, which correlated closely with human endothelial cell cytotoxicity. Fresh sera also contained this factor, but to a lesser extent. It is argued that the cytotoxic factor detected in previous clinical studies is in part an in-vitro artefact, although its accelerated development in certain patient groups might suggest an excess of pro-oxidants that have developed in vivo.

Fibrin(ogen)olysis in polymyalgia rheumatica and temporal arteritis: preliminary findings on association with disease activity

Postulating an increased production of fibrin(ogen)olytic degradation products (FDP) and an abnormality of fibrinogen metabolism in polymyalgia rheumatica (PMR) and temporal arteritis (TA), we studied 16 PMR/TA patients and 10 control subjects using a sensitive radioimmunoassay for a specific type of FDP, namely, fibrin(ogen)-related D-antigen. Median serum D-antigen levels were increased five-fold in those 11 PMR/TA patients who were untreated compared with control subjects. In the five PMR/TA patients who were treated with prednisone the median D-antigen levels were not significantly different from those of the healthy controls. D-antigen concentration correlated significantly (r = 0.83) with ESR in the seven untreated PMR patients. In PMR patients prednisone therapy was followed by a reduction of serum D-antigen levels.