Rheumatoid arthritis clinical features

It is an autoantibody whose autoantigen is the Fc portion of IgG. Rheumatoid factors may be of any immunoglobulin isotype but it is IgM rheumatoid factor that is commonly measured in rheumatoid arthritis. Classification criteria for rheumatoid arthritis include only one serological test, namely rheumatoid factor. However, it is not diagnostic test rather it may be confirmatory when a number of other clinical features are present. 

Anaemia often becomes a characteristic feature of several chronic diseases, such as rheumatoid arthritis. In most instances this can be linked to lower than normal endogenous serum EPO levels (although in some cases a deficiency of iron or folic acid can also represent a contributory factor). Several small clinical trials have confirmed that administration of EPO increases haematocrit and serum haemoglobin levels in patients suffering from rheumatoid arthritis. A satisfactory response in some patients, however, required a high-dose therapy that could render this therapeutic approach unattractive from a cost benefit perspective. 

Grassi W, De Angelis R, Lamanna G, Cervini C (1998) The clinical features of rheumatoid arthritis. Eur J Radiol 27(1) S18 S24... 

U2. Urowitz, M. B., Gordon, D. A., and Broder, I., Studies into the occurrence of soluble antigen-antibody complexes in disease. V. Second assessment of correlation between rheumatoid biologically active factor (RBAF) and the clinical features of rheumatoid arthritis. Arthritis Rheum. 16, 225-230 (1973). 

In patients with definite or probable methotrexate-induced lung injury, the predominant clinical features include shortness of breath, cough, and fever (13). Pathological examination usually shows an interstitial inflammatory cell infiltrate (sometimes granulomatous or with alveolar damage), and variable degrees of interstitial fibrosis. Unfortunately, confirmatory evidence is sometimes hard to obtain, particularly in patients with rheumatoid arthritis in whom rheumatoid interstitial lung disease can also occur. Infectious pneumonias, particularly viral or Pneumocystis jiroveci pneumonia, which resemble methotrexate pneumonitis and can occur as a result of immunosuppression, should also be carefully excluded. 

Kremer JM, Alarcon GS, Weinblatt ME, Kaymakcian MV, Macaluso M, Cannon GW, Palmer WR, Sundy JS, St Clair EW, Alexander RW, Smith GJ, Axiotis CA. Clinical, laboratory, radiographic, and histopathologic features of methotrexate-associated lung injury m patients with rheumatoid arthritis a multicenter study with literature review. Arthritis Rheum 1997 40(10) 1829-37. 

Despite a good overall safety profile, anti-TNF antibodies can induce a number of adverse effects, including autoimmunity and infections. A trial in the treatment of Crohn s disease noted infusion reactions, transient increased of anti-dsDNA antibodies, and serum sickness-like delayed hypersensitivity with retreatment. Induction of human-antichimeric-antibodies was suggested as the cause of some of the infusion reactions [90]. A prospective study in 35 patients with Crohn s disease showed induction of ANA and anti-dsDNA autoantibodies in 53% and 35% of infliximab-treated patients [91]. A single patient showed clinical features consistent with drug-induced lupus, including the presence of ANA and anti-dsDNA autoantibodies, which quickly resolved after discontinuation of infliximab. Reports on renal adverse effects of anti-TNF antibodies are very rare. Saint Marcoux described the occurrence of crescentic GN in as few as 2 patients out of a cohort of 39 patients, treated with an anti-TNF antibody for rheumatoid arthritis [92]. A case report by Chin et al. [93] described the case of a 29-year-old Australia-born Vietnamese who presented with nephrotic syndrome. A renal biopsy showed membranous nephropathy. Symptoms attenuated after discontinuation of infliximab therapy. 

Delamere JP, Jobson S, Mackintosh LP, Wells L, Walton KW (1983) Penicillamine-induced myasthenia in rheumatoid arthritis its clinical and genetic features. Ann Rheum Dis, 42(5) 500-504. 

Mixed connective tissue disease (MCTD) is an overlap syndrome characterised by a combination of clinical features similar to those of systemic lupus erythematosus, scleroderma, polymyositis, rheumatoid arthritis and unusually high titres of circulating antibody to RNP antigen. 

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