Is Acute Fibrinous and Organizing Pneumonia the Expression of Immune Dysregulation?

Abstract

Acute fibrinous and organizing pneumonia (AFOP) is a recently described histologic pattern of diffuse pulmonary disease. In children, all cases reported to date have been fatal. In this study, we describe the first nonfatal AFOP in a child and review the literature. A 10-year-old boy developed very severe aplastic anemia (VSAA) after being admitted to our hospital with a fulminant hepatic failure of unknown origin. A chest computed tomography scan revealed multiple lung nodules and a biopsy of a pulmonary lesion showed all the signs of AFOP. Infectious workup remained negative. We started immunosuppressive therapy with antithymocyte globulin and cyclosporine to treat VSAA. Subsequent chest computed tomography scans showed a considerable diminution of the lung lesions but the VSAA did not improve until we performed hematopoietic stem cell transplantation 5 months later. Aplastic anemia is associated with a variety of autoimmune syndromes. The sequence of events in our patient suggests that the hepatic failure, AFOP, and the VSAA may all have been part of an autoimmune syndrome. AFOP could be the result of immune dysregulation in this pediatric case with favorable outcome after immunosuppressive therapy and hematopoietic stem cell transplantation.