MICROSCOPIC POLYANGIITIS PRESENTING AS TRANSFUSION-RELATED ACUTE LUNG INJURY IN PATIENT WITH SOLITARY KIDNEY

Abstract

SESSION TITLE: Medical Student/Resident Pulmonary Manifestations of Systemic Disease 1 SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: 10/09/2018 01:15 PM - 02:15 PM INTRODUCTION: Microscopic polyangiitis (MPA) is a type of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAV) characterized by small to medium sized vessel inflammation. We present a rare case of MPA which manifested following blood transfusion for symptomatic anemia. CASE PRESENTATION: A 60 year old female with type 2 diabetes mellitus and hypothyroidism presented with diabetic ketoacidosis (DKA), atrial fibrillation and normocytic anemia. She was managed with IV fluids, insulin drip, and amiodarone with good response. She received 2 units of packed RBCs resulting in respiratory distress and intubation. Chest X-ray showed bilateral fluffy infiltrates with no cardiomegaly. She was transferred to our facility for possible transfusion related acute lung injury (TRALI). She was found to be in acute hypoxic respiratory failure, septic shock and acute kidney injury. She was treated with broad spectrum antibiotics, vasopressors, and inotropes. Suspected TRALI was managed with supportive measures. Renal function continued to deteriorate necessitating dialysis. Patient was difficult to wean from ventilator and required tracheostomy for long term ventilation. Because of lack of improvement and concern for pulmonary renal syndrome, ANCA studies were ordered. Anti-myeloperoxidase (MPO) antibodies were 19.8 (normal <9) and perinuclear antineutrophil cytoplasmic antibody (p-ANCA) titers were elevated at 1:160. Anti-nuclear antibodies were negative. Discussion with multiple specialists concluded that renal biopsy would be risky due to solitary kidney and the patient would not tolerate thoracotomy for open lung biopsy; however, the clinical picture was consistent with microscopic polyangiitis. Under guidance of rheumatology, patient was started on high-dose prednisone and cyclophosphamide. Following this, she showed marked improvement in pulmonary and renal function. Dialysis was stopped and creatinine trended to acceptable levels. She was able to be discharged to rehab facility for physical therapy and subsequently sent home. She did not require dialysis on an outpatient basis. DISCUSSION: This case illustrates the difficulty in diagnosing MPA in the setting of other diseases such as DKA and anemia requiring transfusion. In addition, this case highlights the importance of prompt detection of MPA and AAV as these conditions are quick to respond to immunosuppressive therapies1. Although we were not able to obtain confirmatory tissue biopsy, our patient’s lingering disease was rapidly improved following initiation of immunosuppressive therapy. CONCLUSIONS: This is an interesting case of MPA masking as TRALI with concomitant AKI. While MPA is an uncommon entity2, our case teaches that AAV should be considered in all patients with unexplainable renal dysfunction and pulmonary infiltrates, even without confirmatory biopsy. Reference #1: 1. P H Nachman, S L Hogan, J C Jennette and R J Falk. Treatment response and relapse in antineutrophil cytoplasmic autoantibody-associated microscopic polyangiitis and glomerulonephritis. JASN. January 1, 1996 vol. 7 no. 1 33-39 Reference #2: 2. Watts RA, Mooney J, Skinner J, Scott DG, Macgregor AJ. The contrasting epidemiology of granulomatosis with polyangiitis (Wegener's) and microscopic polyangiitis. Rheumatology. 2012 May;51(5):926-31. https://doi.org/10.1093/rheumatology/ker454. Epub 2012 Jan 17. DISCLOSURES: No relevant relationships by Alexander Goldstein, source=Web Response No relevant relationships by Muhammad Habib, source=Web Response No relevant relationships by Muhammad Malik, source=Web Response No relevant relationships by Lusine Nahapetyan, source=Web Response No relevant relationships by Manish Patel, source=Web Response No relevant relationships by Thien Vo, source=Web Response