J Clin Med Res

Journal of Clinical Medicine Research, ISSN 1918-3003 print, 1918-3011 online, Open Access

Article copyright, the authors; Journal compilation copyright, J Clin Med Res and Elmer Press Inc

Journal website https://jocmr.elmerjournals.com

Case Report

Volume 17, Number 10, October 2025, pages 595-600

A Challenging Case of Immune-Related Organizing Pneumonitis Following Programmed Cell Death 1 Inhibitor Therapy in Non-Small Cell Lung Cancer

Figure 1. Timeline of the clinical case. CT: computed tomography; BAL: bronchoalveolar lavage; CMV: cytomegalovirus; EBV: Ebstein-Barr virus; ED: emergency department; PCR: polymerase chain reaction.

Figure 2. Chest computed tomography scan showing ground-glass opacities, pleural effusion and a crazy-paving pattern in both the lower lobes.

**Table 1.** Recommended Management of Immune-Related Pneumonitis
Grading	Management
BAL: bronchoalveolar lavage; CT: computed tomography; DLCO: diffusing capacity of lung for carbon monoxide; ICI: immune checkpoint inhibitor; IV: intravenous; IVIG: intravenous immunoglobulin.
G1: asymptomatic; confined to one lobe of the lung or 25% of lung parenchyma; clinical or diagnostic observations only	Hold ICI or proceed with close monitoring. Monitor patients weekly with history and physical examination, pulse oximetry; chest imaging (X-ray or CT) if uncertain diagnosis and/or to follow progress. Repeat chest imaging in 3 - 4 weeks or sooner if patient becomes symptomatic. In patients with baseline spirometry or DLCO, repeated testing may be considered in 3 - 4 weeks. May resume ICI with radiographic evidence of improvement or resolution if held. If there is no improvement, treat it as G2.
G2: symptomatic; involves more than one lobe of the lung or 25-50% of lung parenchyma; medical intervention indicated; limiting daily activities	Hold ICI until clinical improvement to G1. Prednisone 1 - 2 mg/kg/day and taper over 4 - 6 weeks. Consider bronchoscopy with BAL ± transbronchial biopsy. Consider empiric antibiotics if infection remains in the differential diagnosis after workup. Monitor at least once per week with history and physical examination, pulse oximetry, consider radiologic imaging; if there is no clinical improvement after 48 - 72 h of prednisone, treat it as grade 3. Pulmonary and infectious disease consults if necessary.
G3: severe symptoms; hospitalization required; involves all lung lobes or 50% of lung parenchyma; limiting self-care daily activities; oxygen indicated	Permanently discontinue ICI. Empiric antibiotics may be considered. Methylprednisolone IV 1 - 2 mg/kg/day. If there is no improvement after 48 h, may add immunosuppressive agent. Options include infliximab or mycophenolate mofetil IV or IVIG or cyclophosphamide. Taper corticosteroids over 4 - 6 weeks. Pulmonary and infectious disease consults if necessary. G4: life-threatening respiratory compromise; urgent intervention indicated (intubation) May consider bronchoscopy with BAL ± transbronchial biopsy if patient can tolerate.

Table 1. Recommended Management of Immune-Related Pneumonitis

Grading

Management

BAL: bronchoalveolar lavage; CT: computed tomography; DLCO: diffusing capacity of lung for carbon monoxide; ICI: immune checkpoint inhibitor; IV: intravenous; IVIG: intravenous immunoglobulin.

G1: asymptomatic; confined to one lobe of the lung or 25% of lung parenchyma; clinical or diagnostic observations only

Hold ICI or proceed with close monitoring.
Monitor patients weekly with history and physical examination, pulse oximetry; chest imaging (X-ray or CT) if uncertain diagnosis and/or to follow progress.
Repeat chest imaging in 3 - 4 weeks or sooner if patient becomes symptomatic.
In patients with baseline spirometry or DLCO, repeated testing may be considered in 3 - 4 weeks.
May resume ICI with radiographic evidence of improvement or resolution if held.
If there is no improvement, treat it as G2.

G2: symptomatic; involves more than one lobe of the lung or 25-50% of lung parenchyma; medical intervention indicated; limiting daily activities

Hold ICI until clinical improvement to G1.
Prednisone 1 - 2 mg/kg/day and taper over 4 - 6 weeks.
Consider bronchoscopy with BAL ± transbronchial biopsy.
Consider empiric antibiotics if infection remains in the differential diagnosis after workup.
Monitor at least once per week with history and physical examination, pulse oximetry, consider radiologic imaging; if there is no clinical improvement after 48 - 72 h of prednisone, treat it as grade 3.
Pulmonary and infectious disease consults if necessary.

G3: severe symptoms; hospitalization required; involves all lung lobes or 50% of lung parenchyma; limiting self-care daily activities; oxygen indicated

Permanently discontinue ICI.
Empiric antibiotics may be considered.
Methylprednisolone IV 1 - 2 mg/kg/day.
If there is no improvement after 48 h, may add immunosuppressive agent. Options include infliximab or mycophenolate mofetil IV or IVIG or cyclophosphamide.
Taper corticosteroids over 4 - 6 weeks.
Pulmonary and infectious disease consults if necessary.
G4: life-threatening respiratory compromise; urgent intervention indicated (intubation)
May consider bronchoscopy with BAL ± transbronchial biopsy if patient can tolerate.