The Case | Hypertension and neuropathy after travel
Authors: Ananda Chapagain, Silvia Marino, Neil Ashman
Journal: Kidney International (2014)

A 45-year-old Caucasian man presented to his general practitioner shortly after returning from a prolonged holiday in Africa and Thailand, with anorexia and malaise. Examination and a basic profile that included a blood count and renal function were unremarkable. Over the next 6 months, he developed progressive anorexia, malaise, and weight loss, and became easily fatigued. He then re-presented to the hospital via casualty with a 10-kg weight loss and a 2-week history of dull pain in his left forearm. He had numbness of the medial part of his left hand. He was found to have new hepatitis B surface and e antigenemia. Over the next fortnight, he developed sensorimotor neurological dysfunction in his right arm and subsequently in the right then the left leg. His systemic symptoms worsened, with fatigue, small joint polyarthralgia, intermittent testicular pain, and fever. He was noted to have new hypertension that was rapidly progressing and requiring four antihypertensive agents for control. On examination, there was significant wasting of upper and lower limb muscles with bilateral median nerve palsies, a left complete ulnar nerve palsy, and predominantly distal muscle weakness. On urinalysis, he had microscopic hematuria, with 4.7 g proteinuria per day. His white cell count was elevated (18.7 × 109/l, normal ratio 4–11), with hypoalbuminemia (29 g/l, NR 37–42) and normal renal function (serum creatinine 49 μmol/l, NR 62–102). ALT was elevated to 71 IU/l (NR 10–40) and hepatitis B viral DNA was detected at 5.03 log IU/ml. HIV, Hep C, cryoglobulins, complement, serum and urine electrophoresis, serum immunoglobulins, syphilis serology, and anti-nuclear antibodies and antineutrophil cytoplasmic antibodies were all negative or normal. He developed sudden abdominal pain and underwent a computed tomography (CT) angiogram of his mesenteric and renal vasculature. (Figure 1). What is the clinical diagnosis? The CT angiogram shows markedly abnormal renal perfusion with segmental areas of infarction. Nerve conduction studies confirmed a severe acute distal and motor sensory axonopathy. Electromyography showed clear evidence of acute denervation as well as ongoing active re-innervation in the proximal leg muscles. The overall findings were consistent with severe mononeuritis multiplex. A sural nerve biopsy and a quadriceps muscle biopsy were also undertaken. The sural nerve biopsy showed an almost complete loss of myelinated fibers in all nerve fascicles with widespread acute axonal degeneration and frequent presence of macrophages. A medium-sized artery in the epineurium was seen with a considerable perivascular cuffing of inflammatory cells, with an infiltration of these cells into the vessel wall with partial destruction of the elastic lamina (Figure 2). A diagnosis of classical polyarteritis nodosa was made on the basis of medium-sized vessel vasculitis on nerve biopsy, with serological evidence of acute hepatitis B seroconversion, and a characteristic clinical presentation (with 5/10 of the American College of Rheumatology criteria1Lightfoot Jr., R.W. Michel B.A. Bloch D.A. et al.The American College of Rheumatology 1990 criteria for the classification of polyarteritis nodosa.Arthritis Rheum. 1990; 33: 1088-1093Crossref PubMed Scopus (942) Google Scholar). Pulsed intravenous methylprednisolone (500 mg intravenously daily for 3 days) and oral lamivudine and tenofovir were commenced. He continued on maintenance oral prednisolone, tapered from a starting dose of 60 mg daily. By day 14, his serum albumin rose to 36 g/l, in the context of rapidly disappearing proteinuria. Six months after diagnosis he had a serum creatinine of 56 μmol/l, normal urinalysis, undetectable hepatitis B viral DNA, and a serum albumin of 42 g/l. Corticosteroids had been withdrawn, although he remained hypertensive with controlled blood pressure on two agents. Traditionally, radiological diagnosis of classical polyarteritis nodosa has rested on mesenteric angiography demonstrating typical medium vessel saccular or fusiform aneurysms in the mesenteric or renal beds.2Hughes L.B. Bridges Jr., S.L. Polyarteritis nodosa and microscopic polyangiitis: etiologic and diagnostic considerations.Curr Rheumatol Rep. 2002; 4: 75-82Crossref PubMed Scopus (30) Google Scholar These occur in 60% or more of patients with PAN, and more than 10 such aneurysms are characteristically seen on arteriography. In an otherwise healthy-appearing vascular tree, areas of arterial tapering, often to occlusion, also occur. CT angiography, although not always able to demonstrate aneurysms, demonstrates the downstream areas of infarction particularly well.3Kato T. Fujii K. Ishii E. et al.A case of polyarteritis nodosa with lesions of the superior mesenteric artery illustrating the diagnostic usefulness of three-dimensional computed tomographic angiography.Clin Rheumatol. 2005; 24: 628-631Crossref PubMed Scopus (12) Google Scholar In the right clinical setting, CT angiography may offer important clues in investigating this often difficult-to-diagnose condition.