Antineutrophilic Cytoplasmic Antibodies Negative Vasculitic Neuropathy

Antineutrophil cytoplasmic antibodies (ANCA) associated vasculitis (AAA) is a systemic disorder involving small vessels. Neuropathy may be associated with the involvement of other organs such as the kidneys, lungs, and heart. ANCA is detected in only 80%-90% of cases; hence, high degree of clinical suspicion is required. We report a case of 49-year-old male patient who had a known case of type-2 Diabetes mellitus and chronic kidney disease on regular peritoneal dialysis. He developed progressive tingling and burning paresthesia and weakness in all four limbs. Examination revealed quadriparesis, hypotonia, areflexia, and sensory loss in the glove and stocking pattern. The nerve conduction study was suggestive of severe generalized axonal sensorimotor neuropathy. He had rapidly progressive breathlessness. High-resolution computed tomography of the chest revealed bilateral ground-glass opacities with interstitial thickening suggestive of interstitial lung disease. He was treated with biweekly hemodialysis. He suffered a cardiac arrest due to an acute myocardial infarction and was successfully revived. Given multisystem involvement, the possibility of small vessel vasculitis was kept. Antinuclear antibodies and ANCA were negative. Sural nerve biopsy was reported as an inflammatory axonopathy, probably vasculitic. The patient was treated as a case of seronegative ANCA with six cycles of injection cyclophosphamide followed by immunosuppression with injection rituximab. He made a steady neurological recovery over 2 years with improved muscle power to grade 3 in both lower limbs and grade 4 in both upper limbs. ANCA may be negative in 10%-20% of cases. AAA should be strongly suspected in the presence of axonal neuropathy with evidence of multisystem involvement. A nerve biopsy can clinch the diagnosis.