Abnormal calcium and magnesium stores in erythrocytes and granulocytes from patients with inflammatory connective tissue diseases. Relationship to inflammatory activity and effect of corticosteroid therapy.

The mass fraction of Ca and Mg in isolated erythrocytes and granulocytes was measured using the nuclear microprobe technique. Conspicuous abnormalities were observed in cells from patients with rheumatoid arthritis and other inflammatory arthritides. Compared with the normal cellular content, total Ca was increased an average of 3 times in erythrocytes and 5 times in granulocytes. Total granulocyte Mg was increased about 3 times, whereas erythrocyte Mg was reduced to as much as 60% of normal. These abnormalities were less prominent or were absent in scleroderma patients, except for levels of granulocyte Ca, which were increased more than 3 times beyond normal in this patient group. A significant positive correlation was found between serum haptoglobin and erythrocyte or granulocyte Ca content among these patients, but not between haptoglobin and erythrocyte or granulocyte Mg values. During corticosteroid treatment, a significant increase in erythrocyte Mg and a significant reduction in erythrocyte Ca were noted, but normalization of these levels was not achieved. Granulocyte Ca was also significantly reduced, while granulocyte Mg remained unaltered. Serum levels of Ca and Mg were within normal ranges and were not influenced by corticosteroid therapy. The results indicate that at least Ca abnormalities in erythrocytes and granulocytes are associated with the intensity of the inflammatory process and that the amounts of Ca and Mg in these cells are influenced by potent antiinflammatory therapy.