Red cell immune adherence (RCIA): its application in cancer and autoimmune disease.

A rosette technique is described which measures the relative activity of the red cell immune adherence (RCIA) receptor. Antibody-coated sheep red cells, in the presence of complement, adhere to human red cells and thus form mixed human-sheep red cell aggregates (RR-rosettes). The percentage of human red cells adhering to one or more sheep red cells is used as the parameter of RCIA activity. The RCIA receptor activity of 23 cancer patients, 13 patients with autoimmune diseases, and 39 age-matched control was compared by investigating the ability of human red cells to adhere to antibody and complement coated sheep red cells and thus form RR-rosettes. We noticed a decrease in the percentage of RR-rosettes forming cells in cancer patients (p less than 0.0005). In contrast, patients with autoimmune disease showed a significant increase in RR-rosettes when compared to age-matched controls (p less than 0.05). Thus malignancy and autoimmune disease are associated with surface changes of erythrocytes, specifically those of the receptors, which are responsible for the immune adherence reaction.