Neurological and pulmonary adverse effects of subcutaneous methotrexate therapy

Interleukin-6-Mediated Inflammation May Cause Methotrexate-Induced Leukoencephalopathy

Children with leukemia treated with methotrexate (MTX) may develop MTX-induced leukoencephalopathy, which can present as seizures or focal neurological deficits. However, the precise pathophysiology has not been fully elucidated. Differences in cytokine/chemokine profiles in cerebrospinal fluid (CSF) between children with MTX-induced leukoencephalopathy and those with posterior reversible encephalopathy syndrome (PRES), an acute neurological condition associated with hypertension, were investigated. Interleukin (IL)-1β, 2, 4, 5, 6, 7, 8, 10, 12, 13, and 17, tumor necrosis factor-alpha, interferon-gamma, granulocyte monocyte colony-stimulating factor, granulocyte colony-stimulating factor, macrophage inflammatory protein-1β, and monocyte chemoattractant protein-1 concentrations were measured in CSF supernatants from 3 children with acute leukemia with MTX-induced leukoencephalopathy, 3 children with acute leukemia with PRES, 6 children with acute leukemia without neurological complications, and 8 children with acute encephalopathy. CSF IL-6 concentrations were higher in children with MTX-induced leukoencephalopathy than in children with acute leukemia with PRES, with acute leukemia without neurological complications, and with acute encephalopathy. We concluded that IL-6 may be involved in the pathogenesis of MTX-induced leukoencephalopathy.

An update on methotrexate

PURPOSE OF REVIEW

Methotrexate (MTX) has been used for the treatment of rheumatoid arthritis (RA) for about three decades now. MTX is one of the most effective and commonly used medicines to treat various forms of arthritis and other rheumatic conditions. MTX was shown to improve signs and symptoms of RA, disease activity and function, to a similar degree as the tumor necrosis factor blockers, and it inhibits radiographic progression to a smaller degree than the antitumor necrosis factor agents. MTX is considered as the anchor drug among the disease-modifying antirheumatic agents, and it is internationally accepted as the first choice in the management of RA. This review was performed on the basis of a PubMed literature search looking at all publications on MTX and arthritis in 2008.

RECENT FINDINGS

MTX seems to even prolong the life span of patients who tolerate the drug and have clinical benefit from this therapy; this may partly be explained by beneficial effects on cardiovascular mortality. The reason for this may well be the suppression of inflammation, but direct atheroprotective effects of MTX may also play a role. MTX is used as monotherapy and in combination with other disease-modifying antirheumatic agents or biologic agents such as the antitumor necrosis factor agents. The 'early' use of MTX within 5 years after disease onset is clearly associated with improved outcomes. The management of RA should include an early strong suppression of inflammation and continuously a tight control strategy. The pharmacodynamics and kinetics of MTX are still incompletely understood.

SUMMARY

In this review, we especially cover the following themes: new clinical studies on the use of MTX in RA, the use of MTX in other rheumatic conditions, prediction of response to MTX, optimal dosage, MTX use in the elderly, the mechanism of action, the pharmacokinetics and the pharmacogenetics of MTX, the prevention of side effects, and the overall long-term safety.