Abstract
Serum immunoglobulin levels were determined in 25 patients with frozen shoulder and in 25 age- and sex-matched controls. Serum IgA levels were significantly reduced (P less than 0.001) in the patients with frozen shoulder and remained so after clinical recovery. Lymphocyte transformation to phytohaemagglutinin in 21 patients also showed significant depression (P less than 0.01). These results support the suggested immunological pathogenesis of this condition.