IDIOPATHIC PULMONARY FIBROSIS A QUICK LOOK .pptx

PULMONARY FIBROSIS A QUICK review

1. IDIOPATHIC PULMONARY FIBROSIS MBBS V LECTURE by Dr Hadiza Umar Muktar 10/7/2025 1

2. Definition Idiopathic pulmonary fibrosis (IPF) is defined as a specific form of chronic, progressive fibrosing interstitial pneumonia of unknown cause, primarily occurring in older adults, limited to the lungs, and associated with the histopathologic and/or radiologic pattern of usual interstitial pneumonia (UIP) 2

3.  Epidemiology IPF is the commonest of all Idiopathic Interstitial Pneumonias Worldwide incidence – 10.7 cases per 100,000 person years for males and 7.4 cases per 100,000 person years for females. Worldwide prevalence – 20 cases per 100,000 persons for males and 13 cases per 100,000 persons for females.  3

4. Age – > 50yrs Sex prevalence – > M>F 4

5. Aetiology  Remains undefined However, some inciting agents have been implicated – Cigarette smoking – Smoke – Environmental pollutants – Viral infections –Gastroesophageal reflux disease – Chronic aspiration – Genetic basis : <5% 5

6. Pathogenesis • Previous theory - generalized inflammation progressed to widespread parenchymal fibrosis. • Current theory - IPF is an epithelial-fibroblastic disease, in which unknown endogenous or environmental stimuli disrupt the homeostasis of alveolar epithelial cells, resulting in diffuse epithelial cell activation and aberrant epithelial cell repair. Re-establishing an intact epithelium following injury is a key component of normal wound healing 6

7.  In IPF, exposure to an inciting agent in a susceptible host may lead to the initial alveolar epithelial damage Following injury, aberrant activation of alveolar epithelial cells leading to release of potent fibrogenic cytokines and growth factors, e.g. TNF-α, TGF-β, platelet-derived growth factor, insulin-like growth factor-1, ET-1 7

8. These are involved in the migration and proliferation of fibroblasts and the transformation of fibroblasts into myofibroblasts myofibroblasts secrete extracellular matrix proteins Failure of apoptosis leads to myofibroblast accumulation, exuberant extracellular matrix protein production, persistent tissue contraction, and pathologic scar formation 8

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10. Clinical features Breathlessness (insidiously progressive disabling) Cough (non-productive) Constitutional symptoms rare (arthralgia, weightless, myalgias) Finger clubbing (25-50%) Crackles (basal, late inspiratory, Velcro) Central cyanosis (advanced cases) Cor pulmonale 10

11. investigation Respiratory function tests usually show a restrictive pattern (FEV1/FVC ratio >70%) with reduced lung volumes and gas transfer. Blood tests , including antinuclear antibodies (ANA) and rheumatoid factor (RF), are performed to exclude autoimmune rheumatic disease but there is no specific serological test for IPF. 11

12. Investigations CXR = abnormal almost all lower zone bi-basal reticular & reticulonodular opacities (interstitial pattern) ‘Honeycomb' appearance (advanced, non-specific) HRCT Diagnostic Patchy, predominantly peripheral, subpleural & basal reticular pattern with subpleural cysts ( honeycombing ) &/or traction bronchiectasis 12

13. BAL is necessary only if an infective or malignant cause is suspected. A differential cell count may show a neutrophilic pattern (neutrophils >3%) is commonly seen in IPF Histological confirmation is necessary in some patients. Surgical lung biopsy, usually via VATS, is the most reliable method for obtaining diagnostic histological samples; transbronchial biopsy can be undertaken bronchoscopically but only obtains small samples. 13

14. Chest radiograph of a patient with idiopathic pulmonary fibrosis showing bilateral lower lobe reticular opacities (red circles). 14

15. Classic subpleural honeycombing (red circle) in a patient with a diagnosis of idiopathic pulmonary fibrosis. 15

16. A patient with IPF and a confirmed histologic diagnosis of usual interstitial pneumonia. Note the reticular opacities (red circle) distributed in both lung bases and the minimal ground-glass opacities (blue circle). 16

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18. Differential Diagnosis 18

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20. All Major criteria + ≥ 3 Minor criteria 20

21. Treatment Can be divided into Non-pharmacologic Pharmacologic Surgical 21

22. Non-pharmacologic • Smoking cessation • Diet: healthy diet/ideal body weight improves QOL • Long term Oxygen therapy – when SpO2<88% or PaO2< 55mmHg • Vaccination against influenza, COVID 19 and pneumococcal infections Pulmonary rehabilitation. 22

23. Pharmacologic • Novel approaches to treatment are being developed based on the new theories of IPF pathogenesis • No optimal medical treatment of IPF is yet to be identified  Prednisone, Azathioprine, and N-acetylcysteine: A Study That Evaluates Response in IPF(PANTHER-IPF) however, worsened outcome, and increased admission rate 23

24. Pirfenidone , an antifibrotic agent, base on ACSEND and CAPACITY 1 and 2 trials has been shown to slow the rate of FVC decline, with the most common side-effects being a reversible photosensitive rash and gastrointestinal disturbance. N intedanib , an intracellular inhibitor of tyrosine kinases 24

25. Surgical • Lung transplantation – definitive treatment – Any patient diagnosed with IPF or probable IPF should be referred for lung transplantation evaluation, regardless of the vital capacity • Indication for listing – DLCO <39% predicted, – 10% or greater decrement in FVC during 6 months of follow-up, – decrease in pulse oximetry below 88% during a 6MWT – or honeycombing on HRCT imaging 25

26. A step-by-step approach to the comprehensive management of patients with idiopathic pulmonary fibrosis (The Lancet http://dx.doi.org/10.1016/S0140-6736(17)30866-8 26

27. Complications Acute exacerbation of IPF (AE-IPF) Commonest/most dreaded Worsens prognosis Usually secondary to infections, pulmonary embolism, or pneumothorax 27

28. Diagnostic criteria for an AE-IPF: • Previous or concurrent diagnosis of idiopathic pulmonary fibrosis • Unexplained worsening or development of dyspnea within 30 days • HRCT scan with new bilateral ground-glass abnormality and/or consolidation superimposed on a background reticular or honeycomb pattern consistent with a usual interstitial pneumonia pattern • Worsening hypoxemia from a known baseline arterial blood gas measurement • No evidence of pulmonary infection by endotracheal aspiration or BAL Exclusion of alternative cause including PE, LVHF 28

29. Other complications  Pulmonary hypertension Respiratory infection Acute coronary syndrome Thromboembolic disease Adverse medication effects Lung cancer 29

30. Prognosis Median survival 3yr (typical) & ≥ 5yrs unusual Poor prognostic factors – >10% decline in FVC (% predicted) over 6 months – DLCO <35% – A decline in DLCO >15% over 1 year – Desaturation below the threshold of 88% during the 6MWT – Progressive decline in DLCO (>15% after 6 mo ) – BAL fluid neutrophilia – Male sex – Age >65 30

31. Conclusion I PF is a chronic progressive fibrosing IP Aetiology is unknown and invariably fatal Bears semblance to a host of other disease entities Diagnosis relies on the clinician integrating the clinical, laboratory, radiologic, and/or pathologic features to make a clinical-radiologic-pathologic correlation that supports its diagnosis. 31