Pseudohypercalcaemia in mixed cryoglobulinaemia (IgMkappa/polyclonal IgG): a rare complication of Sjögren's syndrome.

This is the first reported case of pseudohypercalcaemia associated with type 2 cryoglobulinaemia, secondary to primary Sjögren's syndrome. Pseudohypercalcaemia is an asymptomatic syndrome and does not require specific treatment. However, cryoglobulins have been demonstrated to bind to calcium, affecting the cryoprecipitability, and consequently, altering the pathogenicity of the cryoglobulins. This first report highlights potential for further research into this intriguing phenomenon.