Development of a novel fragments absorbed immunocapture enzyme assay system for tartrate-resistant acid phosphatase 5b.
BACKGROUND
Osteoclastic activity is mainly assessed by measuring urinary markers. To correct for differences in renal clearance, the levels of urinary markers are usually corrected by the urine creatinine concentration. Therefore, alternative serum markers to evaluate osteoclastic activity are required. We developed a novel system for the determination of serum tartrate-resistant acid phosphatase 5b (TRACP5b) activity to evaluate osteoclastic activity.


METHODS
Two unique monoclonal antibodies were generated and the specificity was tested using a surface enhanced laser desorption/ionization time-of-flight mass spectroscopy (SELDI TOF-MS). A novel fragments absorbed immunocapture enzymatic assay (FAICEA) method was developed using 2 monoclonal antibodies.


RESULTS
FAICEA gave a sensitivity 0.1 U/l, linearity of 0.1-28 U/l, recovery 92-103%, inter-assay CV 2.95% and intra-assay CV 2.15%. Unlike other TRACP5b assay systems, FAICEA avoided interference from TRACP 5a.


CONCLUSIONS
According to the FAICEA, postmenopausal women had higher TRACP5b concentrations than younger women. The results show that TRACP5b is a novel bone resorption marker in serum.
Ohashi
Tatsuya
T
Department of Molecular Diagnosis (F8), Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chiba City, Chiba 260-8670, Chiba, Japan. OOHASHIT@jn.nittobo.co.jp
Igarashi
Yoshihiko
Y
Mochizuki
Yoshiko
Y
Miura
Toshihide
T
Inaba
Noriyuki
N
Katayama
Katsuhiro
K
Tomonaga
Takeshi
T
Nomura
Fumio
F
D000135:Acid Phosphatase / Q000032:analysis / Q000097:blood* / Q000276:immunology; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000818:Animals; D000911:Antibodies, Monoclonal / Q000737:chemistry* / Q000302:isolation & purification; D000918:Antibody Specificity; D001862:Bone Resorption / Q000097:blood* / Q000175:diagnosis; D002460:Cell Line; D002648:Child; D005260:Female; D005269:Femur / Q000737:chemistry; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D007128:Immunoglobulin Fragments / Q000737:chemistry*; D007527:Isoenzymes / Q000032:analysis / Q000097:blood* / Q000276:immunology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008875:Middle Aged; D010010:Osteoclasts / Q000502:physiology; D040081:Protein Array Analysis; D017678:Sex Distribution; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D000071681:Tartrate-Resistant Acid Phosphatase
D000911:Antibodies, Monoclonal; D007128:Immunoglobulin Fragments; D007527:Isoenzymes; D000135:Acid Phosphatase; D000071681:Tartrate-Resistant Acid Phosphatase