Secondary pulmonary alveolar proteinosis (PAP) associated with treatment is relatively frequent1,2. However, PAP associated with autoimmune diseases is extremely rare; we have found only 2 cases reported in the literature1,3.
We present a 34-year-old woman diagnosed with systemic lupus erythematosus (SLE) in 2001 based on rash malar, arthritis, leukopenia, positive antinuclear antibody, positive anti-DNA, and hypocomplementemia. She had received immunosuppressive drugs (methotrexate, belimumab, mycophenolate, and leflunomide).
She was admitted to a hospital in September 2014 for the study of respiratory insufficiency. An interstitial pattern could be observed in the thorax radiography and it was interpreted as lupus pneumonitis. She received treatment with methylprednisolone bolus and rituximab.
The patient’s disease course declined and in December 2014 she was referred to our hospital to assess the need for lung transplant. Serological and hematological activity of SLE was discarded. Thoracic computerized tomography showed a crazy-paving pattern (Figure 1). After ruling out lymphoma and infections (including pneumocystis), our main diagnostic suspicion was PAP.
Extensive areas of ground-glass opacity are associated with thickening of interlobular septa, diffuse distribution, and a mosaic pattern.
A bronchoscopy with transbronchial biopsy showed a liquid of milky appearance. Histologic studies revealed an amorphous material by positive periodic acid-Schiff staining in the alveolar space compatible with PAP (Figure 2). Serum granulocyte-macrophage colony-stimulating factor antibody was negative.
Transbronchial biopsy: alveolar spaces occupied with a PAS-positive amorphous acellular material. PAS: periodic acid-Schiff.
According to our results, this patient presents with secondary PAP. Treatment of PAP is whole lung lavage to remove the accumulation surfactant on the air space4. With this therapeutic approach, our patient presented clinical and radiological improvement. She now has good quality of life, and a lung transplant was not necessary.
Footnotes
Because this is a clinical case and not a research activity, this type of work cannot be evaluated by the ethics committees in Galicia. Agreement of institutions’ management was necessary. Requirements and obligations established by health regulations and data protection regulations were respected. Informed patient consent was signed.
