[Articular manifestations of cryoglobulinemias]

Manifestations are found in the joints in 27-50 percent of patients with cryoglobulinaemia. They include arthralgia, or less frequently arthritis of distal oligo-articular topography, predominantly in the lower limbs. These manifestations consist of pure synovitis - nonexudative, nondestructive, and usually recurrent. Cold is rarely a precipitating factor. The manifestations are indicative of cryoglobulinaemia when they are associated with other symptoms of the disorder, among which Raynaud's disease and purpura of the lower limbs are the most frequent. Cryoglobulin is demonstrated only if the blood is centrifuged at 37 degrees C before being held at 4 degrees C. Different immunochemical forms of cryoglobulins exist. The list of disorders that accompany cryoglobulinaemia includes multiple myeloma, Waldenström's disease, idiopathic glomerulonephritis, and, in particular, autoimmune diseases, such as the Sjögren syndrome and disseminated lupus erythematosus. In cases of rheumatoid arthritis, cryoprecipitable proteins are found in the synovial fluid and in the serum. Almost half the cases of cryoglobulinaemia are idiopathic cryoglobulinaemias and constitute the purpura-arthralgia-asthenia-cryoglobulinaemia syndrome. Immunological studies indicate that the mixed cryoglobulins that are characteristic of the idiopathic forms, are the circulating immune complexes that are responsible for the visceral lesions. The mechanism of cryoprecipitation remains unknown. Treatment is mainly symptomatic, as immunodepressants give variable results.