OA35 Early identification of large vessel vasculitis: a specific benefit of a non-specific symptom pathway?
Authors: Machin Russell , Hughes Mark 
Published: April 2023

Abstract

Background/Aims
Since December 2020 in Cornwall there has been a Non-Specific Symptom Pathway (NSSP): a 2-week-wait pathway by which GPs can access a CT thorax, abdomen & pelvis (CT-TAP) to assess non-specific symptoms where there is a suspicion of malignancy, but conventional 2-week-wait referral criteria are not met. An unexpected consequence of this pathway was the finding of cases of suspected large vessel vasculitis (LVV) being referred to rheumatology outpatients.

Methods
Cases with a new diagnosis of LVV or cancer were identified using the NSSP database over the period of December 2021- May 2022. Clinical and laboratory features were analysed and compared. During this time period a Logiq E10 US machine was acquired by the department, enabling axillary US to be performed for some of the suspected LVV cases that were referred to rheumatology.

Results
Of the 241 accepted referrals, 14 patients (5.81%) had a subsequent definite cancer diagnosis, 6 (2.49%) had LVV diagnosed as a direct consequence of the NSSP. 5 (83%) cases of LVV had CRP &gt;60 versus 4 (33%) of the cancer patients where measured. Mean CRP was 38.9 in cancer patients and 82.3 in LVV (normal 0-5mg/L). Mean platelet count was 401 in cancer patients, 510 in LVV patients (normal 150-400x109). 3 LVV patients had immunoglobulins and serum protein electrophoresis tested, of which 2 had significantly raised IgG and 1 was confirmed as polyclonal. In one case, significant thoracic aneurysmal dilatation was identified; a 59-year-old previously healthy woman presented to primary care with fatigue, night sweats and arm pain. Investigations showed anaemia, thrombocytosis, polyclonal high immunoglobulins, CRP 74. CT-TAP via NSSP revealed thoracic aorta wall thickening with aneurysmal dilatation, diameter being 4.5cm at the aortic arch. Subsequently the patient was referred to vascular surgeons and rheumatology. Rheumatology clinic review noted no symptoms of cranial giant cell arteritis or polymyalgia rheumatica. Examination revealed significant blood pressure discrepancy between right and left arms (diastolic difference of 62mmHg) and bilateral axillary bruits. Bilateral axillary artery ultrasound revealed significant intima-media thickening: right distal 1.19mm, left distal 1.37mm (normal less than 0.9mm) consistent with LVV. 10mg Prednisolone and subsequently leflunomide 10mg were initiated with resolution of inflammatory markers and symptoms. Surgical intervention was not felt to be required but regular surveillance continues.

Conclusion
Polyclonal raised IgG, unexplained raised CRP and thrombocytosis, arm blood pressure discrepancy and axillary bruits may be useful indicator tests for referral to the NSSP. LVV diagnosis normally requires extensive inpatient investigations in patients with pyrexia-of-unknown-origin and can be challenging in the absence of PMR or cranial GCA symptoms. As well as early identification of cancer, NSSP has the additional benefit of detecting cases of LVV that may have otherwise gone unnoticed, including the cases with secondary aneurysmal change.
Disclosure
R. Machin: None. M. Hughes: None.