Autoimmune rheumatologic diseases
A 16 year old male who underwent a donor-related (brother) hematopoietic stem cell transplant for aplastic anemia due to paroxysmal nocturnal hemoglobinuria > 1 year prior was transferred to our children’s hospital for new-onset fever, chills, cough, dyspnea on exertion and hemoptysis. Prior treatment for community acquired pneumonia was not effective. Initial laboratory analysis revealed a normal complete blood count and differential, elevated C-reactive protein (CRP) and elevated procalcitonin. Urinalysis was normal. Imaging revealed bilateral pulmonary infiltrates. Broad-spectrum antibiotics and anti-fungal agents were not effective. Studies to identify viral, bacterial, disseminated fungal, and mycobacterial infections were negative. Patient continued to deteriorate clinically. High dose steroid therapy was initiated. The patient rapidly improved on the second day of steroid administration. Due to positive response to steroids, rheumatologic studies were performed. Anti-myeloperoxidase antibody was positive at high titer while anti-proteinase 3, anti-glomerular basement membrane, anti-nuclear antibody and rheumatoid factor were negative. Sinus imaging demonstrated ethmoid, sphenoid and maxillary sinus mucosal thickening and fluid. Upon further history, mother noted a cousin who died of Wegener’s disease. Recent chimerism analysis revealed >98% donor engraftment. Animal models of organ specific and systemic autoimmunity are transferable by bone marrow transplantation. We have identified two reports of ANCA associated vasculitis, one following an autologous and the other following allogenic bone marrow transplantation. This and the positive family history leaves open the possibility that susceptibility to ANCA associated vasculitis rests in the hematopoietic stem cell.