Determination cryoglobulin in sera and evaluation of clinical significance in connective tissue diseases

In this paper,it is reported that sera of 56 cases of normal subjects and 70 cases of connective tissue diseases（25 cases of SLE,16 of RA,10 of PSS,4 of each of DM,AS and BS,3 of RS,2 cases of Raynand’s phnomenon and Henoch-Schönlein Purpura respectively）were examined for cryoglobulin（CG）.The normal value for CG is generally considered to be less than 12 ug/ml. As the results of determination,the positive rate of CG was 72% in DLE,38% in RA,5/10 in PSS,3/4 in DM,2/4 in AS.1/2 in Henoch-Schönlein and none in the rest diseases.Among CG positive patients with SIE,the incidence of renal involvement was 84% in general and the 94% during the active stage,6 CG positive patients with RA being all during the active stage.These results revealed that the determination of cryoglobulin is rather helpful to the diagnosis of immune complex diseases,able to discover the renal injury in time and may be used as one of the measures to evaluate the disease activity.