Different effects of biological drugs in rheumatoid arthritis.

Biological drugs have brought new hope to patients with rheumatoid arthritis (RA) in whom previously existing treatments could not control inflammation, joint destruction, or the progression of disability. The five currently available TNF blockers are approved for treating RA patients, but they have different structures, morphology, pharmacokinetic properties, and activity. Randomised clinical trials (RCTs) have shown that they improve the signs and symptoms of both early and long-standing RA and other inflammatory arthritides, prevent radiographic progression, and improve the patients' health-related quality of life. However, they are more effective in combination with methotrexate (MTX) than alone. Combined treatment is generally well tolerated, and seems to be relatively safe in the short term, as confirmed by RCTs, long-term observational studies and in clinical practice. Patients who fail to respond or develop adverse effects - when treated with one anti-TNF agent can be successfully treated with a second TNF antagonist. However, in the case of primary failure, it is possible that biological agents with a different mechanism of action may be more successful. Tocilizumab alone or in combination with MTX is more effective than MTX monotherapy in reducing disease activity over 24 weeks. Abatacept is well tolerated and retains its efficacy over time, as does rituximab in non-responders to other anti-TNF drugs. Finally, although these drugs improve the quality of life of RA patients, they considerably increase direct medical costs.

Lung involvement and drug-induced lung disease in patients with rheumatoid arthritis.

Interstitial lung disease (ILD) is a common extra-articular manifestation of rheumatoid arthritis (RA) and a significant cause of morbidity and mortality. Usual interstitial pneumonia and nonspecific interstitial pneumonia seem to be the most frequent patterns in RA patients with ILD, although the proportion of patients with usual interstitial pneumonia is higher than among patients with other systemic rheumatic autoimmune diseases. RA patients with ILD most frequently present with chronic symptoms of cough and dyspnea when climbing stairs or walking uphill. A physical examination may reveal inhalatory crackles and a pulmonary function test demonstrates restrictive physiology, often with reduced diffusing capacity. High-resolution computed tomography is generally sufficient to confirm a diagnosis of ILD, although a minority of cases may require a surgical lung biopsy. Conventional disease-modifying antirheumatic drugs such as methotrexate (MTX) or leflunomide (LEF) and biological agents such as TNF-blocking agents or rituximab may trigger or aggravate ILD in RA patients, and infections may contribute to increased mortality in such patients. LEF should not be used in patients with a history of MTX pneumonitis. The prevalence of interstitial pneumonia among RA patients treated with anti-TNF agents ranges from 0.5 to 3%; however, as the evidence that anti-TNF increases or decreases the risk of ILD is controversial, it is not clear whether this indicates more severe RA requiring biological therapy or the effect of exposure to potentially toxic drugs such as MTX or LEF. The development of treatment-related ILD is a paradoxical adverse event, and patients should be warned about this rare but serious complication of biological or disease-modifying antirheumatic drug therapy.