Hepatitis C Associated with Polyarteritis Nodosa Bindiya Magoon, MD ACP Associate member, Elias Ghandour, MD, Good Samaritan Hospital, Baltimore, Maryland. Introduction: Cryoglobulinemia-associated vasculitis is very well known to be associated with Hepatitis C infection (HCV). However, a Polyarteritis Nodosa type illness (PAN) is relatively uncommon and only few cases have been reported in the literature. We report a case of Hepatitis C presenting as PAN. History: A 50- year old Caucasian male presented to the hospital with arthalgias, myalgias, marked asymmetric weakness progressively worsening over 3 months of both upper and lower extremities causing ataxia and physical disability. His history was also significant for a 50 pound weight loss, recurrent episodes of abdominal pain, polyuria, and polydipsia. His past medical history included bipolar disorder and alcoholism. Physical exam: Patient was cachetic and emaciated. Vitals were unremarkable. He had bilateral foot drop and right wrist drop with sensory loss to all modalities over both feet, suggestive of mononeuritis multiplex. Labs and Imaging: Hb-12, Hct-35%, Wbc- 8200, BUN-27, Cr-2.2 (increased over time to 4.2), AST-95, ALT-60. Urine- Pr-1+, RBC-0. Hepatitis C Ab positive, Hep C RIBA positive, HIV negative, HbsAg negative, SPEP- Increased Gamma globulins with polyclonal pattern. ANA positive with speckled pattern, Cryoglobulins (repeated samples) Negative. Renal Bx- Small and medium vessel vasculitis, with interstitial nephritis; negative for Cryoglobulins. All other serologies were negative. Hosptal Course: Due to worsening renal function with negative serologies, the patient underwent renal biopsy, which showed medium and small vessel vasculitis. His clinical course was also complicated by generalized seizures. MRI findings were consistent with cerebritis. He was initially pulsed with steroids and started on maintenance dose of cyclophosphamide and prednisone. There was progressive improvement in muscle weakness and neuropathy, with no further seizures. However, there was no improvement in renal function, and the patient eventually required initiation on hemodialysis. Conclusion: Although Hepatitis C infection is classically associated with cryoglobulinemic vasculitis, polyarteritis nodosa-type vasculitis should be considered. Markers for Hepatitis C have been found in 5-12% of patients with PAN. Differentiation between polyarteritis nodosa and cryoglobulinemic-type vasculitis can be difficult because both diseases share close clinical manifestations and pathologic lesions. ANCA is also rare in both conditions and fails to contribute to the diagnosis. However, some features found in HCV- infected patients with PAN vasculitis have not been reported in cryoglobulin disease such as micro- aneurysms and renal cortical necrosis secondary to occlusion of medium-size arteries. The mechanisms that cause PAN type vasculitis are unclear. References: 1.Cacoub P, Maisonobe T, Thibault V, et al. Systemic vasculitis in patients with hepatitis C J Rheumatol 2001;28:109–18. 2.Polyarteritis nodosa and cryoglobulinemic glomerulonephritis related to chronic hepatitis C. Canada R, Chaudhary S, Gaber L, Waters B, Martinez A, Wall B. Am J Med Sci Jun;331(6): Interstitial Nephritis Medium Vessel Vasculitis Medium vessel Vasculitis