Interstitial lung diseases (ILDs) are a group of disorders characterised by scarring and inflammation of the lung interstitium, common examples of which include idiopathic pulmonary fibrosis (IPF)and sarcoidosis. ILD is a challenging condition given the progressive nature of the disease which over time leads to worsening respiratory symptoms, poor quality of life and reduced life expectancy.
This blog describes a typical ILD patient journey from the initial diagnosis through its long-term management to end-of-life care. A better understanding of the ILD patient journey can help guide research in the area helping to improve patient care and ILD outcomes.
The beginning of the journey
The ILD patient journey begins with the patient visiting their primary care physician (PCP). Often ILD patients may visit their PCP multiple times and will receive numerous incorrect diagnoses and medications before ILD is suspected. One study found that 55% of all ILD patients receive at least one wrong diagnosis and 38% had two wrong diagnoses before being correctly diagnosed [1]. The high levels of misdiagnosis in ILD can be ascribed to the non-specific symptoms of ILD which cause it to be mistaken for other common respiratory conditions e.g. asthma, bronchitis [1]. Other contributing factors include a lack of PCP knowledge of ILD symptoms, the poor sensitivity of diagnostic tests in particular x-rays and the presence of comorbidities (e.g. Gastroesophageal reflux disease) that can mask ILD symptoms.
Those patients who show no improvement in their symptoms are often then referred to a pulmonary specialist. Around 30% of ILD patients visit their PCP at least four separate times before referral [2]. Following their referral, many patients will need to undergo invasive procedures e.g. lung biopsy to confirm their diagnosis. One study found 61% of ILD patients underwent bronchoscopy or surgical lung biopsy, 45% a surgical lung biopsy and 21% may undergo both procedures to confirm a diagnosis of ILD [3]. These procedures can be stressful for patients and also carry significant risks. Consequently, ILD patients may wait as long as 4 to 5 years to receive a confirmatory diagnosis of ILD [2], This wait can impose a significant emotional toll on sufferers and impact their overall quality of life
Diagnosis to disease management
A confirmatory ILD diagnosis is important for the initiation of the appropriate treatment. Those available pharmacological treatments, while not curative, can provide patients with some relief from ILD symptoms and help improve their overall quality of life [4–6]. Other non-pharmacological options for ILD include pulmonary rehabilitation and oxygen therapy. One study found that over 40% of patients who attended a specialist ILD clinic were referred for pulmonary rehabilitation [7]. Pulmonary rehabilitation can improve exercise capacity, quality of life and lung disease knowledge in ILD patients [7].
As ILD progresses many patients begin to experience declines in lung function, worsening disease symptoms and a lower quality of life [8]. Consequently, ILD patients are required to attend regular clinic follow-up appointments. These follow-up appointments typically involve the patient undergoing repeat imaging and pulmonary function testing [9]. However, many patients with advanced ILD report challenges in being able to both travel to and attend clinic appointments and perform pulmonary function tests e.g. spirometry due to their worsening respiratory symptoms [10].
Some ILD patients may also experience acute exacerbations characterised by the rapid onset of breathlessness, coughing, fatigue and sometimes fever. ILD exacerbations may occur because of disease progression or may be triggered by infections, gastroesophageal reflux disease, air pollution or certain medications. It is estimated that 4% of IPF patients experience an acute exacerbation each year [11]. ILD patients who experience exacerbations may be admitted to hospital where they receive antibiotics and supportive care. Approximately half of all ILD patients who suffer an exacerbation do not survive to discharge [11].
The end of the journey
At the end of their journey, ILD patients experience significant escalations in disease symptoms and declines in functional capacity. Some ILD patients may undergo a lung transplant of either one or both lungs. Lung transplants can be life-saving for ILD patients with a median survival of around 7 years [12]. The procedure itself is however not without risk with an estimated 20% of patients not surviving 1-year post-transplant [13]. The long-term prognosis for ILD patients who do not undergo lung transplantation is significantly poorer with a median survival of 3 to 4 years post-diagnosis [14]. Consequently, many ILD patients spend the last few months of their life in a hospital or hospice facility [15].
In conclusion, the journey for many ILD patients is a difficult one fraught with many challenges. These challenges include inaccurate and delayed diagnoses, limited treatment options with the ability to halt ILD progression and poor patient monitoring. Addressing these challenges will be key to optimising patient outcomes and improving the quality of life of ILD sufferers.
References
[1] Cosgrove GP, Bianchi P, Danese S, et al. Barriers to timely diagnosis of interstitial lung disease in the real world: the INTENSITY survey. BMC Pulm Med. 2018;18:9.
[2] Lamas DJ, Kawut SM, Bagiella E, et al. Delayed Access and Survival in Idiopathic Pulmonary Fibrosis. Am J Respir Crit Care Med. 2011;184:842–847.
[3] Lederer DJ, Bianchi P, Loboda J, et al. AB017. Interstitial lung disease patient diagnostic journey (intensity). J Thorac Dis. 2016;8:AB017–AB017.
[4] Pitre T, Kawano-Dourado L, Kachkovski G V, et al. Systemic corticosteroids in fibrotic lung disease: a systematic review and meta-analysis. BMJ Open Respir Res. 2023;10:e002008.
[5] Richeldi L, du Bois RM, Raghu G, et al. Efficacy and Safety of Nintedanib in Idiopathic Pulmonary Fibrosis. New England Journal of Medicine. 2014;370:2071–2082.
[6] King TE, Bradford WZ, Castro-Bernardini S, et al. A Phase 3 Trial of Pirfenidone in Patients with Idiopathic Pulmonary Fibrosis. New England Journal of Medicine. 2014;370:2083–2092.
[7] Hoffman M, Mellerick C, Symons K, et al. Pulmonary rehabilitation for interstitial lung disease: Referral and patient experiences. Chron Respir Dis. 2021;18:147997312110460.
[8] Maqhuzu PN, Szentes BL, Kreuter M, et al. Determinants of health-related quality of life decline in interstitial lung disease. Health Qual Life Outcomes. 2020;18:334.
[9] National Institute for Health and Care Excellence (NICE). Idiopathic pulmonary fibrosis in adults: diagnosis and management Clinical guideline [Internet]. 2013. Available from: www.nice.org.uk/guidance/cg163.
[10] Kumar D. Assessment and follow-up of interstitial lung disease. Indian J Rheumatol. 2021;16:69.
[11] Collard HR, Ryerson CJ, Corte TJ, et al. Acute Exacerbation of Idiopathic Pulmonary Fibrosis. An International Working Group Report. Am J Respir Crit Care Med. 2016;194:265–275.
[12] Chambers DC, Cherikh WS, Harhay MO, et al. The International Thoracic Organ Transplant Registry of the International Society for Heart and Lung Transplantation: Thirty-sixth adult lung and heart–lung transplantation Report—2019; Focus theme: Donor and recipient size match. The Journal of Heart and Lung Transplantation. 2019;38:1042–1055.
[13] NHS Blood and Transplant. Benefits and Risks of Lung Transplants [Internet]. [cited 2024 May 12]. Available from: https://www.nhsbt.nhs.uk/organ-transplantation/lung/benefits-and-risks-of-a-lung-transplant/.
[14] Kolb M, Vašáková M. The natural history of progressive fibrosing interstitial lung diseases. Respir Res. 2019;20:57.
[15] Cross SH, Ely EW, Kavalieratos D, et al. Place of Death for Individuals With Chronic Lung Disease. Chest. 2020;158:670–680.
