OBJECTIVE: Quantification of serum nucleotide
pyrophosphohydrolase (NTPPHase) activity in healthy subjects
and in patients with various rheumatic diseases or with
quad/hemiplegia, hemodialysis, or renal transplant.
Colorimetric assay of enzyme activity in serum.
NTPPHase activity in 85 healthy subjects was independent of
age or sex and was highly reproducible in each individual. The
biologic and methodologic coefficients of variation were
nearly identical. Elevated enzyme levels were found in sera
from patients with osteoarthritis/spondylosis, calcium
pyrophosphate dihydrate (CPPD) crystal deposition,
scleroderma, fibromyalgia, or hemodialysis. Renal transplant
patients receiving cyclosporine had the highest enzyme
activity of any group, whereas transplant patients not taking
this drug had normal levels. Histograms of values in all
groups showed a normal distribution.
NTPPHase activity levels were significantly elevated in
patients with degenerative arthritis whether or not CPPD
crystals were present, in patients with either scleroderma or
fibromyalgia, and in patients receiving hemodialysis therapy
or taking cyclosporine.