Alveolar proteinosis in a patient recovering from Pneumocystis carinii infection: a case report with a review of literature

BACKGROUND: Pulmonary alveolar proteinosis is a rare lung disorder, which was first reported as idiopathic condition in 1958. The prevalence of acquired pulmonary alveolar proteinosis has been estimated to be 0.37 per 100,000 population. The cause of this condition is not entirely clear. We present alveolar proteinosis in a case recently treated for pulmonary Pneumocystis carinii infection. CASE PRESENTATION: A 25-year-old Caucasian female presented with shortness of breath during management of acute pancreatitis. She had a heart-transplant six years ago, a distal pancreatectomy secondary to pancreatitis two years ago, chronic renal failure secondary to Prograft taken for six years to suppress transplant rejection, and a more recent history of Pneumocystis carinii infection treated in the preceding 21 days with augmented doses of Bactrim (Trimethoprim, Sulfamethoxazole). She had bilateral pleural effusions with radiological and clinical features suspicious for interstitial lung disease. Cytopathologic evaluation of broncho-alveolar lavage (BAL) showed hyaline alveolar casts admixed with amorphous debris and scant chronic inflammatory cells, consistent with alveolar proteinosis. GMS and PAS stains were negative for P. carinii. Direct Fluorescent Antibody (DFA) test for P. carinii performed on the BAL specimen in our Microbiology Lab had been repeatedly negative. CONCLUSION: Cytopathological findings in bronchoalveolar lavage, with clinical differential diagnosis of interstitial lung disease, were diagnostic. Pulmonary alveolar proteinosis after recent treatment for P. carinii infection suggests a relationship of pulmonary alveolar proteinosis with P. carinii infection in the immunocompromised patient.