We report a patient with acute fibrinous and organizing pneumonia (AFOP). The clinical manifestations, course and treatment of this entity have not been fully characterized.
A healthy 31-year-old, non-smoking, African-American female presented elsewhere with progressive dyspnea over two months. She denied other symptoms. Chest radiograph showed bilateral patchy infiltrates. Room air (RA) ABG were PaO2 88, PaCO2 35, pH 7.42. No history of recent travel or inhalational exposures. Only medication was oral contraceptives. CT scan revealed basilar predominance of patchy airspace disease, without lymphadenopathy. WBC was 11,800/mm3 with normal differential; collagen vascular & HIV screen negative. Lung biopsy was reviewed at the Armed Forces Institute of Pathology, confirming a diagnosis of AFOP. Prednisone 30 mg was given for 5 days with two week taper. Three days after discontinuation, she was dyspneic at rest. Thereafter she was admitted to our hospital. Her RA PaO2 was 61 mmhg with oxygen saturation (SpO2) 81% when walking. WBC was 16,000/mm3 (with left shift). Imaging studies showed worsening of bilateral lower lobe alveolar-interstitial infiltrates. Prednisone (1mg/kg) and antibiotics were started. BAL was negative for infection. Pulse IV steroids were given for 3 days with some improvement. She was discharged on prednisone 80 mg/day and oxygen (resting SpO2 86-88%). Prednisone was tapered to 40 mg/day over the first month as her RA SpO2 increased to 94%; CT showed resolution of ground glass attenuation (GGA) with persistent fibrotic changes at lung bases. After 4 months she was at 15 mg/day with resting SpO2 97% (exercise SpO2 80%). Her CT scan revealed renewed GGA at lung bases. PFT data are summarized in Table. Prednisone was increased to 20 mg/day for two months, again with decrease in GGA. She has now been on prednisone for 9 months, currently 15 mg/day. She is stable with good resting SpO2 (exercise 88%).
The recent ATS/ERS classification of idiopathic interstitial pneumonias (1) does not include AFOP. This entity was recognized in 2002 as an unusual pattern of acute lung injury, distinct from both diffuse alveolar damage and organizing pneumonia (2). Seventeen patients (ages 33 to 78) had presented with an acute or subacute course. Progressive dyspnea was the major symptom, with cough, fever and chest pain also commonly occurring. Although multiple co-morbidities were identified, no pattern of causality emerged. The most common radiological pattern was bilateral basilar infiltrates. Its distinctive feature is intra-alveolar fibrin in the form of fibrin “balls” in a patchy distribution, accompanied by a mild-to-moderate lympho-plasmacytic infiltrate. Two patterns of disease were recognized: fulminant illness with rapid progression to death (1-5 weeks) and a sub-acute course with recovery. Mortality in that study was high (59%), with a poor response to steroid therapy. Our patient was younger than previously described. No specific causality was identified. She improved slowly after pulse steroids, with stability during a slow taper over several months. Disease activity flared at four months, requiring the steroid dose to be raised. She has currently required prednisone therapy for 9 months. Periodic CT scanning has shown resolution of GGA, reflecting active inflammation, but basilar fibrosis and honeycombing developed. Her DLCO is markedly abnormal.
A subacute presentation of AFOP may respond to pulse doses of IV steroids. Suppression of disease activity may require at least 6–12 months of steroid therapy. CT scanning helps recognize renewed inflammatory activity and guide therapy. Fibrosis and honeycombing occur in AFOP. Table 1.
Pulmonary Function TestsMonths on SteroidFiveNineMeasured (% of predicted)Measured (% of predicted)SpirometryFVC (Liters)Liters2.36 (66%)2.73 (76%)FEV1Liters2.06 (67%)2.50 (81%)FEV1/FVC%8791VolumesTLCLiters3.84 (78%)4.03 (82%)RVLiters1.48 (108%)1.30 (95%)RV/TLC%3932Diffusion CapacityDLCOml/mmHg/min6.8 (24%)6.8 (24%)DLCO/VAml/mmHg/min/l2.29 (40%)2.05 (35%)Pulse OximetryResting%9497Post Exercise%8188
A.S. Bawa, None.