At the time of referral to our hospital, the reticular shadows were enlarged on chest radiography and the crazy paving appearance was enlarged and well-defined on chest computed tomography (B). with steroids and initiation of immunosuppressive agents for anti-ARS antibody-positive interstitial pneumonia, respiratory failure and chest imaging findings showed worsening of the condition. Bronchoscopy was repeated, and milk-like alveolar lavage fluid was collected; serum anti-granulocyte macrophage colony-stimulating factor antibody was identified. Steroids and immunosuppressive agents were gradually tapered and discontinued, and the patients condition stabilized after repeated alveolar lavage under general anesthesia. Conclusion Due to similar presentation, PAP can be misdiagnosed as interstitial pneumonia. If pulmonary lesions due to interstitial pneumonia are exacerbated by immunosuppressive treatment, physicians should reconsider the diagnosis and include PAP in the differential diagnosis. strong Ditolylguanidine class=”kwd-title” Keywords: Anti-ARS antibody, Anti-PL-7 antibody, Autoimmune alveolar proteinosis, Steroid, Case report Background Pulmonary alveolar proteinosis (PAP) is attributed to the accumulation of surfactant-derived lipoprotein compounds in the alveolar space owing to disturbed macrophage differentiation and function [1]. Approximately 90% of cases are autoimmune PAP (APAP), which is diagnosed by the detection of anti-granulocyte macrophage-colony stimulating factor (GM-CSF) antibodies in the serum [2, 3]. Anti-GM-CSF antibodies play a pivotal role in the disturbance of macrophage differentiation and function in the lungs of patients with APAP. The standard therapy is whole lung lavage [3], with inhaled GM-CSF therapy having potential as a future treatment [4]. Anti-aminoacyl-tRNA synthetase (anti-ARS) antibodies are myositis-specific autoantibodies that have been identified in a subset of patients with interstitial pneumonia who do not present with dermatomyositis or polymyositis [5, 6]. Interstitial pneumonia with anti-ARS antibody is commonly treated with steroids or immunosuppressive agents and is usually responsive to these therapies [7]. In this report, we describe the case of a patient with APAP who had been treated with steroids and immunosuppressive agents for interstitial pneumonia associated with anti-ARS antibody positivity. Case presentation A 66-year-old Japanese man presented with dyspnea on exertion for the previous 4?months and had visited a different hospital 2?months prior to his presentation at our hospital. His smoking history was 0.5 pack year. Chest radiography revealed small nodular and reticular shadows, predominantly in Ditolylguanidine the lower lung fields, and a chest computed tomography scan revealed diffuse ground-glass shadows and partial interlobular septal thickening, known as crazy paving appearance (Fig.?1A). Serum KL-6 was markedly elevated at 10,513?U/mL; however, the bronchoalveolar lavage fluid (BALF) was not milky in appearance, and the BALF cell analysis revealed elevated lymphocytes (82%). In addition, anti-ARS antibody in the serum was detected; thus, a diagnosis of interstitial Ditolylguanidine pneumonia with positive anti-ARS antibodies was made in the patient; prednisolone and cyclosporine treatment were initiated. Following treatment initiation, the patient rapidly developed respiratory failure, and he was transferred to our hospital 1?month after prednisolone and cyclosporine were initiated. Vital signs on admission were: body temperature, 37.1?C; pulse, 88 beats per minute; blood pressure, 130/93?mmHg; and oxygen saturation (SpO2), Rabbit polyclonal to Wee1 93% with 15?L/min O2 inhalation using a reservoir mask. On chest auscultation, fine crackles were heard in both lungs. There was no muscle grasp pain or weakness, and no skin findings suggestive of dermatomyositis, such as heliotrope rash or Gottrons sign, were noted. An arterial blood gas analysis (measured when the patient was on 15?L/min of oxygen through a reservoir mask) showed a pH of 7.460, PaCO2 of 36.1?mmHg, PaO2?of 69.2?mmHg, and HCO3?of 25.4?mmol/L. Laboratory findings are shown in Table ?Table1.1. KL-6 and carcinoembryonic antigen levels were ?5000?U/mL and 19.4?ng/mL, respectively. A commercial anti-ARS antibody assay (mixture of Jo-1, PL-7, PL-12, EJ, and KS antigens) was positive, but tests Ditolylguanidine for anti-nuclear antibodies and other specific autoantibodies, including anti-Jo-1, were negative. Subsequently, the anti-ARS antibody was evaluated by immunoprecipitation and found to be an anti-PL-7 antibody. Chest radiography revealed an enlargement of diffuse reticular shadows, and chest computed tomography revealed a wide distribution of well-defined crazy-paving appearance (Fig.?1B). We suspected PAP and decided to perform a bronchoscopy. The patients respiratory condition was poor; bronchoscopy was performed under ventilator control with tracheal intubation. Bronchoalveolar lavage revealed cloudy milk-like fluid. Serum anti-GM-CSF antibody level was 5.2?g/mL ( ?1.0?g/mL), and APAP was diagnosed. Thereafter, prednisolone and cyclosporine were tapered off. Total lung lavage under general anesthesia was performed twice for both lungs over a period of 6?months,.
At the time of referral to our hospital, the reticular shadows were enlarged on chest radiography and the crazy paving appearance was enlarged and well-defined on chest computed tomography (B)
