(49 days)
Osteomark is a urinary assay that provides a quantitative measure of the excretion of cross-linked N-telopeptides of type I collagen (NTx) as an indicator of human bone resorption. Elevated levels of urinary NTx indicate elevated human bone resorption. Measurement of NTx is intended for use in:
A. Predicting skeletal response (bone mineral density) to hormonal antiresorptive therapy in postmenopausal women.
B. Therapeutic monitoring of:
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- antiresorptive therapies in postmenopausal women
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- antiresorptive therapies in individuals diagnosed with osteoporosis
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- antiresorptive therapies in individuals diagnosed with Paget's disease of bone
- estrogen-suppressing therapies
C. Assessing the relative risk for loss of spinal bone mass after one year if not treated with hormonal antiresorptive therapy
Osteomark is a competitive enzyme-linked immunosorbent assay (ELISA) which utilizes a horseradish peroxidase labeled monoclonal antibody directed against the cross-linked N-telopeptides (NTx) present in urine specimens. An Osteomark® kit is comprised of the following reagents:
Antigen Coated 96-Well Plate Calibrators: 1 nM BCE 30 nM BCE 100 nM BCE 300 nM BCE 1000 nM BCE 3000 nM BCE Antibody Conjugate Concentrate Antibody Conjugate Diluent Level I and Level II Urine Controls 30X Wash Concentrate Buffered Substrate Chromogen Reagent Stopping Reagent
The solid phase utilizes microwells onto which NTx has been adsorbed. NTx in the specimen or Calibrator competes with the solid phase NTx for antibody binding sites. The resulting amount of Antibody Conjugate bound to the solid phase is indirectly proportional to the amount of NTx in the specimen or Calibrator. The quantity of NTx in the specimen is determined from a standard calibration curve using reagents supplied in the kit. Assay values are standardized to an equivalent amount of bone collagen, and are expressed in nanomole bone collagen equivalents per liter (nM BCE). BCE reflects the amount of immunoreactive NTx, as measured by Osteomark, liberated from human bone collagen following digestion with bacterial collagenase, as measured by hydroxyproline by high performance liquid chromatography (HPLC).
Here's an analysis of the provided text, outlining the acceptance criteria and the studies performed for the Osteomark® device:
Acceptance Criteria and Device Performance Study for Osteomark®
The Osteomark® device is a urinary assay designed to quantitatively measure N-telopeptides of type I collagen (NTx) as an indicator of human bone resorption. The provided documentation details several performance characteristics and studies that likely served as the basis for acceptance criteria.
1. Table of Acceptance Criteria and Reported Device Performance
The document does not explicitly state acceptance criteria with defined pass/fail thresholds for a regulatory submission. Instead, it presents performance characteristics and reference ranges derived from studies. Based on the "Performance Characteristics" section, we can infer the following:
| Acceptance Criteria (Inferred) | Reported Device Performance |
|---|---|
| Expected Values: | |
| Premenopausal Women (mean age 36) | Mean: 35 nM BCE/mmol creatinine, Std Dev: 15, Range: 9-84 |
| Postmenopausal Women ( |
§ 862.1400 Hydroxyproline test system.
(a)
Identification. A hydroxyproline test system is a device intended to measure the amino acid hydroxyproline in urine. Hydroxyproline measurements are used in the diagnosis and treatment of various collagen (connective tissue) diseases, bone disease such as Paget's disease, and endocrine disorders such as hyperparathyroidism and hyperthyroidism.(b)
Classification. Class I (general controls). The device is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to § 862.9.