Nonspecific interstitial pneumonia (NSIP) is one class of idiopathic interstitial pneumonia (IIP). NSIP is chronic interstitial pneumonia with the homogeneous appearance of interstitial fibrosis and inflammation. It is nonspecific as it lacks the histopathological features of the other subtypes of the IIP. NSIP typically has bilateral lung involvement and may have a predisposition for the lower lobes.
Nonspecific interstitial pneumonia can be idiopathic or associated with connective tissue disease, HIV infection, toxins, or numerous other causes. Secondary causes of nonspecific interstitial pneumonia NSIP include:
NSIP is rare. It constitutes 14% to 36% of cases of idiopathic interstitial pneumonia which is less common than usual interstitial pneumonia (UIP) (50% to 60%) but more common than desquamative interstitial pneumonia, respiratory bronchiolitis-associated interstitial lung disease (DIP/RB-ILD) (10-17%) and acute interstitial pneumonia (AIP) (0% to 2%). Idiopathic NSIP occurs mostly in middle-aged women who are non-smokers, while NSIP due to connective tissue disease is equal in men and women.
For the diagnosis of diffuse interstitial lung disease, surgical biopsy via VATS or thoracotomy is the gold standard. Transbronchial cryobiopsy can be used as well. Traditional transbronchial forceps lung biopsies have been reported to have a low diagnostic yield. Ideally, biopsy samples should be obtained from more than one lobeNSIP is a diagnosis of exclusion. Nonspecific gross findings may be observed on wedge biopsy, including increased stiffness of the pulmonary parenchyma secondary to interstitial inflammation and fibrosis. The histopathology of NSIP is characterized by a temporally homogeneous inflammatory and fibrosing interstitial process. Fibroblastic foci and peripheral accentuation are typically absent, which helps to differentiate it from usual interstitial pneumonia (UIP). NSIP is also characterized by diffuse alveolar wall thickening by uniform fibrosis, but with the preservation of the alveolar architecture. Three separate groups within NSIP have been described:
The evaluation of the patients with possible NSIP include:
Treatment of NSIP depends on the cause and the severity of the disease:
Treatment of the secondary causes:
The prognosis of NSIP is significantly better than that of UIP. Five and 10-year survival is 43% and 15% respectively among patients with UIP, compared to 86% to 92% 5-year survival and 26% to 40% 10-year survival rates among patients with NSIP with the fibrotic component. Fibrotic NSIP is thought to have a worse prognosis than inflammatory, cellular NSIP.
The diagnosis and management of NSIP is complex and usually requires a team approach that consists of a pathologist, thoracic surgeon, pulmonologist, radiologist, nurse practitioner and an internist. Once the diagnosis is made, the usually treatment for mild disease is observation. Moderate to severe disease usually requires steroids and other potent immunosuppresive agents. These patients need life long follow up as the disease course is marked by relapses and remissions. The prognosis for mild disease is good but for severe disease the life expectancy is significantly reduced. (Level V)
|||Hochhegger B,Marchiori E,Zanon M,Rubin AS,Fragomeni R,Altmayer S,Carvalho CRR,Baldi BG, Imaging in idiopathic pulmonary fibrosis: diagnosis and mimics. Clinics (Sao Paulo, Brazil). 2019 Feb 4; [PubMed PMID: 30726312]|
|||Abdelghani R,Thakore S,Kaphle U,Lasky JA,Kheir F, Radial Endobronchial Ultrasound-guided Transbronchial Cryobiopsy. Journal of bronchology [PubMed PMID: 30676396]|
|||Wu EK,Ambrosini RD,Kottmann RM,Ritchlin CT,Schwarz EM,Rahimi H, Reinterpreting Evidence of Rheumatoid Arthritis-Associated Interstitial Lung Disease to Understand Etiology. Current rheumatology reviews. 2019 Jan 15; [PubMed PMID: 30652645]|
|||Sambataro G,Sambataro D,Pignataro F,Torrisi SE,Vancheri A,Pavone M,Palmucci S,Del Papa N,Vancheri C, Interstitial Lung Disease in patients with Polymyalgia Rheumatica: A case series. Respiratory medicine case reports. 2019; [PubMed PMID: 30603602]|
|||Cottin V,Hirani NA,Hotchkin DL,Nambiar AM,Ogura T,Otaola M,Skowasch D,Park JS,Poonyagariyagorn HK,Wuyts W,Wells AU, Presentation, diagnosis and clinical course of the spectrum of progressive-fibrosing interstitial lung diseases. European respiratory review : an official journal of the European Respiratory Society. 2018 Dec 31; [PubMed PMID: 30578335]|
|||Richeldi L,Varone F,Bergna M,de Andrade J,Falk J,Hallowell R,Jouneau S,Kondoh Y,Morrow L,Randerath W,Strek M,Tabaj G, Pharmacological management of progressive-fibrosing interstitial lung diseases: a review of the current evidence. European respiratory review : an official journal of the European Respiratory Society. 2018 Dec 31; [PubMed PMID: 30578333]|
|||Jain A,Shannon VR,Sheshadri A, Immune-Related Adverse Events: Pneumonitis. Advances in experimental medicine and biology. 2018; [PubMed PMID: 30539509]|
|||Jakubczyc A,Neurohr C, [Diagnosis and Treatment of Interstitial Lung Diseases]. Deutsche medizinische Wochenschrift (1946). 2018 Dec; [PubMed PMID: 30508858]|
|||Greenberger PA, Hypersensitivity pneumonitis: A fibrosing alveolitis produced by inhalation of diverse antigens. The Journal of allergy and clinical immunology. 2018 Nov 15; [PubMed PMID: 30448501]|