Nephrotic Syndrome as an Initial Manifestation of GPA: A Diagnostic and Therapeutic Challenge
Abstract
Introduction
Granulomatosis with polyangiitis (GPA) is a rare multisystemic inflammatory disease characterized by vasculitis affecting small and medium-sized vessels. Its prevalence ranges from 2.3 to 146 cases per million people, with an incidence of 0.4 to 11.9 cases per million person-years. With a predilection for the respiratory tracts and kidneys, it can affect virtually any organ. Although its etiology remains unknown, it is believed to originate from various stimuli in genetically susceptible patients. Diagnosis depends on clinical manifestations and laboratory tests, including anti-neutrophil cytoplasmic antibodies (ANCA). Due to its clinical variability, timely diagnosis can be crucial to avoid fatal outcomes. We present a clinical case of GPA with nephrotic syndrome as an initial presentation, an atypical manifestation of renal involvement in this disease.
Case Information
A 50-year-old woman with multiple comorbidities, including hypertension, diabetes, obesity, hypothyroidism, and non-obstructive coronary artery disease, consulted for constitutional symptoms and recurrent anemia. Multiple pulmonary nodules and nephrotic syndrome were observed. She was admitted for severe anemia and pneumonia, developing hypertensive crisis and pericardial effusion. Renal biopsy revealed necrotizing glomerulonephritis with ANCA-related vasculitis, specifically granulomatosis with polyangiitis. She started treatment with intravenous methylprednisolone and cyclophosphamide, required renal replacement therapy, and experienced infectious complications. She improved with rituximab and antibiotics and was eventually discharged in remission.
Conclusion
The case of GPA with nephrotic syndrome as an atypical presentation highlights the importance of early diagnosis and timely treatment. The reviewed literature underscores the diversity of clinical presentations of GPA and the challenges in its diagnosis, emphasizing the need to maintain a high clinical suspicion and conduct thorough evaluations in patients with nonspecific symptoms.