ABSTRACT
A 75-year-old woman, with hypertension and atrial fibrillation but no prior renal history, presented to the hospital for chest discomfort and dyspnea. She was found to be in acute renal failure, with a serum creatinine of 5.1, increased from a baseline of 0.9, and urine analysis revealing proteinuria and hematuria with dysmorphic red blood cells. Subsequent work up was significant for positive perinuclear antineutrophil cytoplasmic antibody (p-ANCA) and myeloperoxidase antibodies. She underwent a renal biopsy, which revealed necrotizing crescents in 12 of 14 glomeruli, and she was diagnosed with rapidly progressive glomerulonephritis due to microscopic polyangiitis. Despite aggressive treatment with plasmapheresis, high-dose prednisone, and rituximab infusions, renal function worsened, and she required initiation of hemodialysis. She was ultimately discharged after a three-week admission, with plans to continue rituximab infusions and three times weekly hemodialysis in the outpatient setting. Due to her poor response to traditional therapies, initiation of a new targeted immunomodulator known as avacopan, a complement 5a receptor antagonist, was considered. Such targeted immunomodulators are also of particular interest as possible ways to reduce the risk of severe infection associated with current broad immunosuppressive modalities. In addition, when used in place of steroids, they reduce the morbidity associated with cumulative glucocorticoid toxicity. For patients with ANCA-associated vasculitis refractory to standard therapies, targeted immunomodulators such as avacopan should be considered as alternative or adjunct therapy.
ABSTRACT
Fever of unknown origin (FUO) is defined as a fever higher than 38.3ºC for at least three weeks. It remains a difficult diagnostic challenge and it carries well over 200 differential diagnoses, including infectious, rheumatologic and malignant etiologies. A methodological approach with clinical deductive reasoning and value-based investigative work-up can establish the diagnosis. This case is about a 76-year-old male with a past medical history of atrial fibrillation, bladder cancer treated with chemotherapy (now in remission) and hydronephrosis with recent ureteropelvic junction stent placement. He presented to the emergency department (ED) for worsening shortness of breath (SOB), weakness, and fevers. His initial workup was notable for a urinary tract infection which was treated with ceftriaxone. However, there was only a limited improvement in the fever. Diagnostic imaging was negative on initial review. He was evaluated by consultants of different specialities including infectious disease, rheumatology, and hematology. Ultimately, the decision was made to discharge the patient home on steroids with further outpatient workup. He returned four weeks later with worsening fever and was found to have new-onset mediastinal lymphadenopathy. A biopsy of an inguinal lymph node was obtained which showed high grade-B cell lymphoma. The patient was continued on prednisone and started on chemotherapeutic agents which included vincristine, rituximab and cyclophosphamide. Shortly after starting treatment, the patient and family elected for hospice. This case demonstrates the importance of continuously questioning the diagnosis at hand and of keeping an open mind when evaluating a patient with FUO.
