The mass fraction of calcium (Ca), magnesium (Mg), manganese (Mn), iron (Fe). zinc (Zn), strontium (Sr) and copper (Cu) in isolated granulocytes, erythrocytes and platelets was measured using the nuclear microprobe technique. The cellular profile of metal variation was conspiciously altered in patients (n = 29) with ankylosing spondylitis compared with the profile found in age and sex matched healthy controls. Ca was accumulated in erythrocytes and granulocytes but decreased in platelets (p less than 0.001). Mg was increased in granulocytes but appeared in reduced concentrations in platelets and erythrocytes (p less than 0.001). The cellular amounts of Mn was increased in granulocytes (p less than 0.001), normal in platelets (p greater than 0.05) and subnormal in erythrocytes (p less than 0.001). Zn was reduced in all 3 cell types (p less than 0.001). Fe accumulation was evident in granulocytes and platelets (p less than 0.001). Sr was only measurable in granulocytes from patients. Cu was below the detection limit in the different cell types isolated from patients, but appeared in measurable amounts in erythrocytes and platelets from controls. The granulocyte amounts of Ca, Mg, Mn and Sr were strongly related to the acute phase reaction. Negative correlations were found between erythrocyte Mg and Zn and the inflammatory activity. The patients had increased serum levels of Cu, normal levels of Ca, Mg and Sr and decreased levels of Zn, Fe and Mn. No relationship was found between the serum concentrations of these elements and their respective cellular stores, except for a weak negative correlation between granulocyte and serum Fe.(ABSTRACT TRUNCATED AT 250 WORDS)