Abstract: PUB163
Microscopic Polyangiitis Presenting as Severe Anemia and AKI in a Female Adolescent
Session Information
Category: Glomerular Diseases
- 1402 Glomerular Diseases: Clinical, Outcomes, and Therapeutics
Authors
- Luft, Hannah E., University of Georgia School of Medicine, Athens, Georgia, United States
- Miller, Toni-Ann, University of Georgia School of Medicine, Athens, Georgia, United States
- Cardenas, Luis, University of Georgia School of Medicine, Athens, Georgia, United States
- Pena, Julio E., Georgia Kidney Consultants, Watkinsville, Georgia, United States
Introduction
Microscopic polyangiiitis (MPA) is a rare ANCA-associated small-vessel vasculitis that mainly affects the kidneys and lungs. Although rare in young adults, it may present with nonspecific symptoms that delay diagnosis. We report an 18-year-old previously healthy female presenting with symptomatic anemia and acute kidney injury, highlighting subtle early findings of a rapidly progressive and perhaps irreversible vasculitic process.
Case Description
An 18-year-old female with a history of iron deficiency anemia presented with chest pain and exertional dyspnea with multiple visits over 6 months for similar symptoms.
Initial laboratory evaluation showed microcytic anemia with hemoglobin 6.4 g/dL & hematocrit 22.4%. Anemia studies showed iron 21 mcg/dL, ferritin 58 ng/mL, iron saturation 9%, and TIBC 246 mcg/dL.
Renal studies showed creatinine 2.57 mg/dL, BUN 26 mg/dL, and eGFR 27 mL/min. Urinalysis showed 70 mg/dL of protein, large blood, 10-20 WBC & 2+ hyaline casts. One month prior, creatinine was 1.36 mg/dL and urinalysis showed 3+ protein and 1+ blood. Renal ultrasound was negative.
Nephrology was consulted for renal biopsy, which showed crescenteric glomerulonephritis with moderate interstitial fibrosis and tubular atrophy. Serologic workup revealed a positive myeloperoxidase antibody and ANCA with titer of 1:1280.
Induction therapy began with rituximab and IV methylprednisolone. She was transitioned to prednisone with avacopan initiated outpatient. Despite treatment, the patient experienced progressive renal decline requiring peritoneal dialysis and transplant evaluation.
Discussion
MPA commonly presents with necrotizing glomerulonephritis and pulmonary capillaritis. Severe anemia may result from chronic pulmonary hemorrhage without overt hemoptysis. In patients with anemia along with acute kidney injury whose findings are not fully explained by common etiologies, ANCA-associated vasculitis should remain a diagnostic consideration.
Diagnosis of MPA was delayed in this case despite laboratory abnormalities and progression of symptoms. Given her young age, good health, and abnormal uterine bleeding history, symptoms were attributed to iron deficiency anemia due to menorrhagia despite progressive renal dysfunction. Reassessment of the differential diagnosis is critical when clinical findings do not align with the presumed diagnosis, as delayed recognition may lead to progressive renal injury.