40. A case of large vessel vasculitis presenting with limb claudication symptoms

INTRODUCTION: This is a case report of extensive large vessel vasculitis which initially presented to the vascular team with limb claudication symptoms and an absent radial pulse. CT angiogram was suggestive of a large and medial vessel arteritis, without a significant elevation in ESR. CASE DESCRIPTION: A 71-year-old gentleman was referred from the vascular team to the rheumatology outpatient clinic. He initially attended orthopaedics and was awaiting shoulder surgery. He reported pain and intermittent colour changes in his left hand and was noted to have an absent radial pulse. CT angiogram was suggestive of a large and medium vessel arteritis such as giant cell arteritis. The CT aorta showed occlusion of the left axillary artery with significant narrowing of the left subclavian. He had a known history of cataracts, mixed frequency hearing loss, cervical spondylosis and previous arthroscopic sub acromial decompression surgery. He had intermittent mild jaw pain for a few months but no other clinical symptoms in keeping with vasculitis. He had no headache, scalp tenderness or constitutional symptoms. ESR was 41. Temporal artery biopsy was positive. Histology was in keeping with temporal arteritis but there was no giant cells or granulomata seen. CT PET showed increased tracer uptake within the subclavian, axillary and the common carotid arteries bilaterally. There was also slightly increased tracer extending inferiorly to the aortic arch and within the proximal descending thoracic aorta. He was commenced on 60mg prednisolone OD, omeprazole, adcal D3, alendronate, aspirin and cotrimoxazole. A month later, he presented with chest pain and was diagnosed with acute coronary syndrome. He had extensive imaging and there was no evidence of dissection. He had five coronary stents inserted and was commenced on dual anti platelet therapy for one year. He was commenced on tocilizumab as a steroid sparing agent taking into consideration the severity and extent of his disease, the need for dual antiplatelet therapy and increased bleeding risk. DISCUSSION: This was an interesting case of extensive large vessel vasculitis without a significant inflammatory response. He had extensive disease with both large vessel and cranial involvement. We held off on steroid treatment until he was investigated with CT PET and biopsy as his symptoms were longstanding. He was a high risk candidate for long term steroids given his recent MI and need for dual antiplatelet therapy. We opted for tocilizumab as a steroid sparing agent given the extent and severity of vessel involvement and increased bleeding risk on antiplatelet treatment. Tocilizumab is licensed for relapsing and remitting GCA and has the ability to limit steroid use and reduce the risk of relapse. Tocilizumab was used as an effective steroid sparing agent in this case. KEY LEARNING POINTS: This case has shown that extensive large vessel involvement can be seen in vasculitis without a significantly inflammatory response. ESR was only 41 in this case despite the extent of vasculitis. Therefore we must keep an open mind when considering a diagnosis of vasculitis as inflammatory markers may be normal. Tocilizumab was used an effective steroid sparing agent and has helped to limit steroid use in the setting of increased bleeding risk. In patients presenting with these clinical findings, we would have a low threshold for requesting temporal artery biopsy. This patient has established damage due to the extensive vessel involvement and it will be difficult to assess whether symptoms are related to damage or disease activity. How do we best assess whether symptoms are related to damage or disease activity? What is the best imaging to monitor disease activity? How best do we manage this patient’s disease in the long term due to the extent of vessel involvement? CONFLICTS OF INTEREST: The authors have declared no conflicts of interest.