Expanded spectrum of antineutrophil cytoplasmic antibody–negative vasculitis involving vessels from capillaries to medium‐sized arteries

Abstract

The patient was admitted to a local hospital 2 weeks priorfor a 3-month duration of weight loss, generalized weak-ness, and progressive lower extremity pain. The symptomsstarted gradually, without any notable antecedent event.He felt weak, lost appetite, and developed intermittent drycough and pain in the lower extremities, initially in thethighs, and progressed to bilateral legs. In a matter ofmonths, his health deteriorated from being physically ac-tive and independent to mostly bedridden.Evaluation at the local hospital revealed low-grade fever(37.9°C), mild hypertension (140–150/90 mm Hg), multi-ple new lung nodules on a contrast-enhanced chest andabdominal computed tomography (CT) scan, and an ele-vated serum creatinine concentration of 2.6 mg/dl (fromhis baseline of 0.9 mg/dl approximately 6 months ago)with microscopic hematuria. Screening for hepatitis B andC, antinuclear antibodies, complements, and antineutro-phil cytoplasmic antibody (ANCA) panel (myeloperoxi-dase [MPO] and proteinase 3) was negative. His erythro-cyte sedimentation rate (ESR) was 49 mm/hour (referencerange 0–25). A transbronchial biopsy sample of severallung nodules showed no evidence of malignancy or activeinfection and was interpreted as nondiagnostic. For hislower extremity pain, he was empirically treated withintravenous (IV) immunoglobulin for possible Guillain-Barre´ syndrome. The treatment was discontinued 4 dayslater after an electromyogram sample revealed primaryaxonal sensory motor peripheral neuropathy. His kidneydysfunction worsened following intravenous contrast ex-posure for the CT scan; his serum creatinine level rose to3.4 mg/dl. He underwent a left kidney percutaneous bi-opsythatwasreadaspossiblecrescenticglomerulonephri-tis. IV methylprednisolone, 500 mg once daily, was initi-ated. During his hospital stay, the patient developedepisodic confusion. A spinal tap was performed andshowed no abnormality, nor evidence of syphilis or WestNile virus infection. Two days following the initiation ofIV methylprednisolone, his condition further deterioratedwith worsening extremity weakness to the point that hecould not ambulate with assistance and mental confusion.He was then transferred to our institution.