The Nucleoprotein Complement-Fixation Test in the Diagnosis of Systemic Lupus Erythematosus

A gamma-globulin factor in the serum of patients with systemic lupus erythematosus that reacts with isolated cell nuclei1 or nucleoprotein2 , 3 has been detected in many ways.4 The standard method of demonstrating this factor remains the L.E.-cell test, which is a complex process involving the reaction of a component of the cell nucleus with the serum lupuserythematosus factor and subsequent phagocytosis of the altered nuclear material.5 Other methods for the detection of antinuclear antibodies have proved useful both clinically and in immunologic investigations. These include the identification of gamma globulin present on cell nuclei by measurement of its ability to decrease . . .