It was with great interest that we read the study by Mathew et al. (1). We thank the authors for their elegant and detailed functional analyses of circulating blood dendritic cells in sarcoidosis.
From a clinical standpoint, one conclusion of the authors needs commenting and a word of caution.
The authors use the widely accepted chest x-ray staging system proposed by Scadding in 1961 (2) as a measure of pulmonary disease activity and correlate it with in vitro measures of myeloid dendritic cell function and in vivo measures of delayed type hypersensitivity responses. They conclude that in vitro myeloid dendritic cell function correlates with in vivo measures of pulmonary disease severity.
The Scadding chest x-ray staging system is a purely descriptive and somewhat arbitrary classification that is generally accepted to correlate poorly overall with pulmonary disease activity and progression in patients with sarcoidosis (3).
Therefore, we believe that the above conclusion has to be interpreted with great caution. Also, it would have been interesting to include stage IV (fibrosis) in the analysis, since it may correlate less poorly with disease activity than the other stages (4). Markers of disease activity that distinguish better between treatment-responsive inflammatory lesions and treatment-nonresponsive fibrotic lesions than chest x-ray staging are high resolution CAT scanning (5), functional-anatomical imaging techniques like gallium or positron emission tomography (PET) scanning (6, 7, 8), and, last but not least, the clinician’s assessment of the clinical findings.
New scoring systems to assess disease activity have recently been proposed but still need validation (4, 9).
- Copyright © 2009 by The American Association of Immunologists, Inc.
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