Cryoglobulins and cold agglutinins for hand arm vibration syndrome.

BACKGROUND: Hand arm vibration syndrome (HAVS) is a condition caused by hand transmitted vibration from the use of hand-held vibrating tools or workpieces. The disease affects the vascular, neurological and musculoskeletal systems. The vascular component of HAVS is a form of secondary Raynaud's phenomenon. Other causes of disease must be excluded before attributing the cause to hand transmitted vibration. AIMS: To evaluate the prevalence, and utility of testing for, cryoglobulins and cold agglutinins in patients with HAVS symptoms. METHODS: A retrospective cohort study of 1183 patients referred for HAVS clinical assessment at St. Michael's Hospital, Toronto, Canada, between 2014 and 2020. The standard operating procedure at the clinic includes a detailed clinical and exposure history, physical examination, objective investigations and blood tests. Data were retrieved from patient chart review and laboratory investigation results for all cases with cryoglobulin and cold agglutinin testing. RESULTS: A total of 1183 patients had a serum cryoglobulin measurement. Eleven patients (1%) were positive. Seven positive results were 'low titre' (1% positive) and the other four results were 2%, 6%, 9% and 18%. The patient with a 9% positive cryoglobulin titre had previously diagnosed Sjögren's syndrome. There were no positive cold agglutinin tests in the 795 patients tested. CONCLUSIONS: Routine testing for cryoglobulins and cold agglutinins in patients with HAVS symptoms is not recommended because test positivity rates are negligible. Testing may be considered if the clinical history or routine blood investigations suggest evidence of underlying cryoglobulinaemia or cold agglutinin disease.