Serum chemistry of Ahsg-deficient mice. (a) Serum electrolytes are given as the mean ± SE of at least six mice for each measurement (**P < 0.01). Where there are no error bars, the SEs were too small to be visible. (b) Sera from C57BL/6-Ahsg+/+ (filled circles) and DBA/2-Ahsg+/+ mice (filled squares) both inhibited the de novo formation of BCP from supersaturated solutions of calcium and phosphate with an IC₅₀ of 0.8% serum. Serum from C57BL/6-Ahsg–/– (open circles) and DBA/2-Ahsg–/– (open squares) mice inhibited at a much reduced rate (IC₅₀ 5.2% and 6.8% serum, respectively). (c) Reconstitution of BCP precipitation inhibition. Note that the reduced inhibition of BCP precipitation by sera from Ahsg-deficient mice could be restored to the WT level by adding back purified mouse serum Ahsg. (d) Serum electrolyte concentrations in normal and calciphylaxis patients (*P < 0.05). (e) Inhibition of BCP precipitation by sera from three healthy subjects (filled circles) and eight calciphylaxis patients (open circles). Note that the inhibition of BCP precipitation is greatly reduced in all calciphylaxis patients. (f) Serum reconstitution by purified human Ahsg in serum of a calciphylaxis patient. Note that the reduced inhibition of BCP precipitation by serum from the calciphylaxis patient could be restored to normal levels by adding back purified human serum Ahsg.