RESEARCH - Variation of immunological response in MTX-induced pneumonitis

December 11, 2010

Rheumatology (Oxford). 2008 Nov;47(11):1647-50. Epub 2008 Sep 23.

Variation of immunological response in methotrexate-induced pneumonitis.

Chikura B, Sathi N, Lane S, Dawson JK.

Department of Rheumatology, Royal Liverpool University Hospitals,

Prescot Street, Liverpool L78XP, UK.

Abstract

OBJECTIVES: To assess the variation of peripheral blood and

bronchoalveolar lavage (BAL) inflammatory cell counts and lung biopsy

findings with the degree of exposure to MTX therapy.

METHODS: Fifty-six (16 males; 40 females) reported cases of

MTX-induced pneumonitis (MTX-P) on low-dose MTX (5-30 mg) were

identified from a literature search and classified using Searles and

McKendry's criteria. The median cumulative dose was 300 mg and this

was used to categorize patients into low and high MTX-exposure groups

and 6 months was used to divide patients into early- and late-onset

MTX-P groups.

RESULTS: Neutrophil counts in the peripheral blood and BAL were

significantly raised in the low MTX-exposure group compared with the

high MTX-exposure group (P = 0.018 and 0.038, respectively). There

were similar findings when early-onset was compared with late-onset

group. Lymphocytes in BAL were significantly higher in the high

MTX-exposure group compared with low-dose cumulative group (P =

0.007). There were 6 (11%) recorded deaths and all were in the low

MTX-exposure group. Early-onset/low MTX-exposure groups had a high

prevalence of lung fibrosis.

CONCLUSIONS: This is the first study to describe the variation of

immunological responses in MTX-P with the degree of exposure to MTX.

Our findings suggest that MTX-P can be divided into two groups: type 1

MTX-P that occurs early, predominated by neutrophils, lung fibrosis

and has a high mortality; and type 2 MTX-P that occurs late,

predominated by lymphocytes, has less lung fibrosis and low mortality.

PMID: 18812430

full article:

Not an MD

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