Abstract
“Cryptogenic” and “idiopathic” have different roots and slightly different meanings, which could reconcile the seemingly opposing views on terminology for idiopathic pulmonary fibrosis http://ow.ly/mvMb30nc2te
To the Editor:
A recent paper by Wolters et al. [1] has raised considerable interest and stirred some debate regarding whether or not the word “idiopathic” should still be part of the name of the disease that we currently call idiopathic pulmonary fibrosis (IPF) [2]. The authors stated that the term idiopathic no longer seemed to describe this progressive lung disease accurately, especially considering the increasing understanding of the causes and pathogenesis of IPF. In a perspective published in the European Respiratory Journal, Wells et al. [3] responded that IPF remains a truly idiopathic fibrotic disease, with no overall explanation for the development of disease, with the exception of genetic predilection and some familial cases.
I suggest that IPF is indeed idiopathic, although the word idiopathic is generally used somewhat spuriously, and that this debate would gain from an etymological approach. Although in medicine, the word idiopathic is generally used to describe a condition for which no cause has been identified, this usage has somewhat drifted from its etymology. The word idiopathic comes from the ancient Greek ιδιοσ (idios, one's own, proper, particular) and πάθος (páthos, suffering, i.e. disease). Therefore, idiopathic literally means something like “a disease of its own”. Although this may often be related to a condition that has no particular cause, the roots are different from those of cryptogenic, from the Greek κρυπτός (hidden) and γένεσις (origin).
IPF has previously been called cryptogenic fibrosing alveolitis in the UK, and it is only recently that the terminology of IPF has been used internationally [4]. Cryptogenic and idiopathic have different roots and slightly different meanings. Based on etymology, the word idiopathic applies better than cryptogenic to what we call IPF, a process with relentless, progressive fibrosis. Although it can be argued that some causes and risk factors of IPF are progressively identified, including tobacco smoking, occupational exposures and genetic risks (and therefore that IPF is not always cryptogenic), pulmonary fibrosis is often compared to abnormal or uncontrolled wound healing, and is indeed a process that progresses “on its own” once initiated [5].
Knowledge of this distinction might help to reconcile the seemingly opposing views on terminology [1, 3] and the use of the word idiopathic in its original sense. In addition, the fact that pulmonary fibrosis is a chronic, progressive and uncontrolled pathogenic process is much better appreciated by patients and relatives than the widely used explanation that idiopathic means that the doctors ignore the cause of this disease, which is a terrible idea for the patient [6].
Footnotes
Conflict of interest: V. Cottin reports receiving the following, outside the submitted work: personal fees and non-financial support from Actelion, Boehringer Ingelheim and Roche for consultancy, lectures and travel to meetings; grants to his institution from Boehringer Ingelheim and Roche; personal fees from Bayer/MSD and GSK for consultancy; personal fees from Gilead for acting as a member of an adjudication committee; personal fees from Novartis for consultancy and lectures; a grant from Sanofi for acting as a trial investigator; personal fees from Promedior for acting as the Chair of the DSMB; personal fees from Celgene for the DSMB; and personal fees from Galapagos for consultancy.
- Received December 5, 2018.
- Accepted December 6, 2018.
- Copyright ©ERS 2019