A 63 year-old male presented with a 2 week history of hemoptysis and shortness of breath. He had no weight loss, rashes, sinus disease, sore throat, mouth sores or sick contacts. His blood pressure was elevated and he developed dyspnea requiring non-invasive positive pressure ventilation. His examination was significant for crackles throughout the lung fields bilaterally. He had no jugular venous distention or edema. His initial blood investigations revealed a creatinine of 7.0 mg/dL, blood urea nitrogen of 76 mg/dL, anemia, normal coagulation indices and a high C-reactive protein. Urinalysis showed hematuria and proteinuria without cellular casts. CT scan of the chest showed extensive bilateral ground glass opacities (Figure 1). Due to his tenuous respiratory status, he was treated for presumed vasculitis with pulse dose steroids and plasmapheresis. By day 3 his hemoptysis had resolved and his dyspnea improved. Further results revealed positive anti-myeloperoxidase (MPO) antineutrophil cytoplasmic antibody (ANCA) and low-titer antinuclear antibody. Renal biopsy performed on day 4 suggested severe tubular atrophy, interstitial fibrosis, and diffuse mesangial proliferative and sclerosing glomerulonephritis with immune complexes (Figure 2). Open lung biopsy showed diffuse intra-alveolar hemorrhage without vasculitis. He was discharged on oral steroids.
MPO ANCA is associated with microscopic polyangiitis which may present with pulmonary-renal syndrome. Pauci-immune glomerulonephritis (GN) and pulmonary capillaritis or diffuse alveolar hemorrhage are most commonly described. Although immune complexes have been reported, immunofluorescent staining is usually mild in these cases. Our case represents the rare finding of intense immunofluorescence and crescentic GN with MPO ANCA and pulmonary hemorrhage. In our research, we found another reported case treated with plasmapheresis, steroids and cyclophosphamide. For our patient, steroids were continued but more toxic treatment was not started because it was determined that the kidney disease was too advanced and there was no evidence of pulmonary vasculitis.
This rare case of MPO ANCA-associated immune complex pulmonary-renal syndrome presented diagnostic and therapeutic dilemmas to the medical team. Our patient’s pulmonary hemorrhage responded favorably to steroids and plasmapheresis. We are uncertain if our case represents an unusual coincidence or a new manifestation of an ANCA-associated vasculitis.