Interstitial Pneumonia in Psoriasis

Abstract

ObjectiveTo investigate the relationship between psoriasis and interstitial pneumonia (IP).Patients and MethodsWe analyzed the clinical data of patients with psoriasis treated with biologic agents from June 1, 2008, to June 30, 2017, retrospectively. Chest computed tomography was performed in 392 patients before treatment. The clinical characteristics and radiographic findings of these patients were evaluated.ResultsOf the 392 patients with psoriasis, IP was detected in 8 patients (2%). Bilateral ground-glass and/or irregular linear (reticular) opacity in the lower lung zone was the most common chest computed tomography finding. Five of the 8 patients with IP were treated with anti–interleukin (IL) 12/IL-23 or IL-17 antibodies, leading to decreased or stable IP activity.ConclusionInterstitial pneumonia was detected in 2% of patients with psoriasis who needed systemic treatments. Ground-glass and/or irregular linear (reticular) opacity in the bilateral lower lobes was characteristic of IP with psoriasis. The IL-23/IL-17 axis may play important roles in the pathogenesis of IP in psoriasis.

Reply to Gohar on ‘Lungs, methotrexate and psoriasis’, a comment on ‘Fatal, incidental, idiopathic pulmonary fibrosis in a patient receiving long‐term low‐dose methotrexate for psoriasis’

“…In addition, it should be emphasized that many apparent case reports of ‘pulmonary fibrosis’ arising in the context of MTX treatment for psoriasis are in fact spurious, including the reference mentioned in Dr Gohar's article by Karadag et al ., which describes a case of resolving interstitial pneumonitis not fibrosis. With regard to the Japanese populations with psoriasis and interstitial pneumonia (IP) that Dr Gohar alludes to, it is of interest that the prevalence of IPs is greater than the background prevalence of the most common form of chronic IP, which is idiopathic pulmonary fibrosis . Regarding our patient, we suggest that there were two possibilities: (i) there was no connection between his psoriasis and interstitial lung disease (ILD), i.e.…”

Comment on ‘Fatal, incidental, idiopathic pulmonary fibrosis in a patient receiving long‐term low‐dose methotrexate for psoriasis’

“…Almost all blood flows into the pulmonary circulation, suggesting that the lung parenchyma is susceptible to systemic inflammation in psoriasis. No epidemiological studies searching for comorbidities in psoriasis have revealed a high prevalence of interstitial pneumonia (IP) in psoriasis, indicating that clinically relevant IP might be rare in patients with psoriasis …”

“…The interleukin (IL)‐23/IL‐17 axis may play important roles in the pathogenesis of both psoriasis and IP, although a direct role for this pathway in the IP observed in the patients with psoriasis remains to be elucidated. Inhibition of this pathway may be effective treatment for IP associated with psoriasis . Higher doses of FA that can be given daily, including on the day of MTX administration, may be suggested for those with risk factors of MTX‐induced IP such as patients aged > 60 years or those with hypoalbuminaemia or diabetes.…”

Lungs, methotrexate and psoriasis

“…The prevalence of IPF is 0.01% in the general population in Japan, thus the prevalence of interstitial pneumonia among patients with psoriasis in a Japanese study seems to be high, as it was detected in 2% of patients with psoriasis who needed systemic treatments. The interleukin (IL)‐23/IL‐17 axis, which plays an important role in the pathogenesis of psoriasis, may play a similar role in the pathogenesis of interstitial pneumonia associated with psoriasis.…”

“…The interleukin (IL)‐23/IL‐17 axis, which plays an important role in the pathogenesis of psoriasis, may play a similar role in the pathogenesis of interstitial pneumonia associated with psoriasis. However, the precise mechanism of the intimate relationship between interstitial pneumonia and autoimmune diseases, including psoriasis, remains speculative …”