Tartrate-resistant acid phosphatase as a biological marker of bone modelling and turnover in women in relation to their gonadal state

Abstract

Serum tartrate-resistant acid phosphatase (TRAP) is considered a biological marker of bone resorption as it is synthesised by osteoclasts. Oestrogens inhibit bone resorption, and this may justify the influence of this hormone on osteoclastic activity. Thus, we have quantified serum TRAP levels in women to define their biological profile and observe any changes in relation to their hormone status.The TRAP level of 18 girls under 5 years of age was 8.1 f 1.7 u/l. This value decreased ( P < 0.001) in girls aged 5 to 12 years ( n = 20, mean 6.3 k 1.3u/l). Following the menarche, another decrease was observed in 12 to 15 year old girls ( n = 25, mean 5.5 5 0.6u/l, P < 0.01). The mean TRAP value continued to decrease during the childbearing years, 16 to 48 ( n = 40,3.8 f 0.3 u/l, P < 0.001). Finally, the mean level increased again at the menopause ( n = 26, 4.5 f 0.4u/l, P < 0@01). In women, serum TRAP changes reflect the dependence of bone modelling and turnover on hormone status.

New evidence that serum β2‐microglobulin behaves as a biological marker of bone remodelling in women

“…These findings suggest that it may be a biological marker of bone remodelling, like BGP. The serum TRAP that we measured is highly specific for osteoclastic activity [20,21]. In postmenopausal osteoporosis and in healthy postmenopausal women it correlates significantly and positively with serum Pz-microglobulin concentration [ 14,151. There are now many methods for evaluating bone mass [29,30], but only histomorphometry [3 11, tomography [32] and radiogrammetry [33,34] provide sufficient definition for measuring ED and ID.…”

“…In every case, CV was less than 6%, referred to a concentration of 2 mg L-I for /Il:-microglobulin and 4 U L-' for TRAP. TRAP was quantified in serum in the Hitachi automated analyser as the substrate a-naphthyl phosphate, using a reagent from Boehringer Laboratories that reacts specifically with isoenzyme 5b synthesized by the osteoclast [20,21].…”

Can a determination of tartrate‐resistant acid phosphatase predict postmenopausal loss of bone mass?

“…In our experience, despite the current vogue for other biological markers of bone resorption [4,5], serum tartrate‐resistant acid phosphatase (TRAP) more than satisfies criteria as a suitable marker of bone resorption. (1) TRAP levels show a significant inverse correlation with estrogen levels before and after they decline in response to gonadotropin‐releasing hormone agonists [6], and in normal circumstances TRAP decreases with menarche and increases after menopause [7]. (2) TRAP levels rise in diseases accompanied by a high rate of remodelling [8].…”

Total and regional bone mass and biochemical markers of bone remodeling in metastatic prostate cancer

“…Therefore, all the TRAP measured in this study was osteoclast-dependent. Although other biological markers of bone resorption are currently in fashion [3,22], TRAP meets more than enough criteria for considering it an adequate marker of bone resorption: 1) It correlates significantly and inversely with estrogen levels before and after Gn-RH agonist treatment [23], and in normal circumstances TRAP decreases with menarche and increases after menopause [24], 2) TRAP is elevated in diseases that are accompanied by a high remodeling rate [25], 3) TRAP correlates negatively with bone mass [23] and positively with alkaline phosphatase [26], as confirmed by this and other studies [23,26], 4) TRAP is sensitive to the effect of drugs that slow remodeling and reduce osteoclastic activity [27], 5) Osteoclastic TRAP is similar to serum TRAP 5b, as shown by electrophoretic mobility on acid gel [28], 6) Its specificity, because circulating TRAP 5b is exclusively osteoclastic in origin, increases its value as a marker of bone remodeling, 7) Finally, its determination in blood is easy [7] and free from the potential errors of markers quantitated in urine. Therefore, we do not think that more expensive markers, which require more complicated and sophisticated techniques, are necessary for evaluating bone resorption.…”