Reagent to measure A1M Levels in human urine samples.
Immunoturbidimetric assay
Anti‑α1‑microglobulin antibodies sensitized to latex particles react with antigen in the sample to form an antigen/antibody complex which, after agglutination, can be determined turbidimetrically. This agglutination is detected as an absorbance change, with the magnitude of the change being proportional to the quantity of A1M in the sample. The actual concentration is determined by interpolation from a calibration curve prepared from calibrators of known concentration.
5.0‑200 mg/L
No automatic re‑run defined. Samples exceeding the measuring range must be diluted manually with 0.9 % NaCl solution; e.g. 1:2.
Limit of Blank | = 1 mg/L |
Limit of Detection | = 2.5 mg/L |
Limit of Quantitation | = 5 mg/L |
These data were generated on cobas c 701 at Denka, based on the Clinical and Laboratory Standards Institute (CLSI) Protocol EP17‑A2. The precision goal for the Limit of Quantitation was a CV % of less than 16 %.
2nd morning urine:
Each laboratory should investigate the transferability of the expected values to its own patient population and if necessary determine its own reference ranges.
Criterion: deviation from initial value: ≤ 20 mg/L: ≤ ± 2 mg/L, > 20 mg/L: ≤ ± 10 %
Hemolysis:
Urea: No significant interference from urea up to a concentration of 2700 mmol/L.
Drugs:
High‑dose hook effect: No false result occurs up to a α1‑Microglobulin concentration of 500 mg/L.
For diagnostic purposes, the results should always be assessed in conjunction with the patient’s medical history, clinical examination and other findings.
ACTION REQUIRED
Special Wash Programming: The use of special wash steps is mandatory when certain test combinations are run together on cobas c systems. All special wash programming necessary for avoiding carry‑over is available via the cobas link, manual input is required in certain cases. The latest version of the carry‑over evasion list can be found with the NaOHD/SMS/SmpCln1+2/SCCS Method Sheet and for further instructions refer to the operator’s manual.
Where required, special wash/carry‑over evasion programming must be implemented prior to reporting results with this test.
|
| Analyzer(s) on which cobas c pack(s) can be used | |
08944547190 | α1-Microglobulin (150 tests) | System‑ID 03 7627 0 | cobas c 701, cobas c 702 |
08944474190 | α1-Microglobulin Calibrator Set (5 × 1 mL) | Code 620‑625 | |
03121313122 | Precinorm PUC (4 × 3 mL) |
| |
03121291122 | Precipath PUC (4 × 3 mL) |
| |
05172152190 | Diluent NaCl 9 % (119 mL) | System‑ID 08 6869 3 |
For cobas c 701/702 analyzers:
A1MGU: ACN 8696
Ready for use
Assay type | 2‑Point End | ||
Reaction time / Assay points | 10 / 22‑38 | ||
Wavelength (sub/main) | 800/570 nm | ||
Reaction direction | Increase | ||
Units | mg/L | ||
Reagent pipetting | Diluent (H2O) | ||
R1 | 100 µL | – | |
R3 | 33 µL | – | |
Sample volumes | Sample | Sample dilution | |
Sample | Diluent (NaCl) | ||
Normal | 10 µL | 10 µL | 90 µL |
Decreased | 10 µL | 10 µL | 90 µL |
Increased | 10 µL | 10 µL | 90 µL |
A1MGU | |
Shelf life at 2‑8 °C: | See expiration date on cobas c pack label. |
On‑board in use and refrigerated on the analyzer: | 12 weeks |
On‑board on the Reagent Manager: | 24 hours |
Diluent NaCl 9 % | |
Shelf life at 2‑8 °C: | See expiration date on cobas c pack label. |
On‑board in use and refrigerated on the analyzer: | 4 weeks |
On‑board on the Reagent Manager: | 24 hours |
Calibrators | S1: H2O (Cal Code 620) S2‑S6: α1-Microglobulin Calibrator Set (Cal Code 621‑625) |
Calibration mode | Spline |
Calibration frequency | Full calibration |
Calibration interval may be extended based on acceptable verification of calibration by the laboratory.
Traceability: This method has been standardized against an internal standard traceable to a nephelometric method.
Representative performance data on the analyzers are given below. Results obtained in individual laboratories may differ.
Precision was determined data using human samples and controls in an internal protocol with repeatability (n = 21) and intermediate precision (2 aliquots per run, 2 runs per day, 21 days). The following results were obtained.
Repeatability | Mean | SD | CV |
Precinorm PUC | 43.5 | 0.258 | 0.6 |
Precipath PUC | 181 | 1.13 | 0.6 |
Human urine 1 | 7.82 | 0.221 | 2.8 |
Human urine 2 | 14.1 | 0.57 | 4.1 |
Human urine 3 | 103 | 1.62 | 1.6 |
Intermediate precision | Mean | SD | CV |
Control Low | 43.7 | 0.592 | 1.4 |
Control High | 180 | 3.08 | 1.7 |
Human urine 1 | 7.82 | 0.347 | 4.4 |
Human urine 2 | 14.1 | 0.703 | 5.0 |
Human urine 3 | 103 | 2.78 | 2.7 |
α1‑Microglobulin values for urine samples obtained on a cobas c 701 analyzer (y) were compared with those determined using the corresponding reagent on a cobas c 501 analyzer (x).
Sample size (n) = 116
Passing/Bablok LREFBablok W, Passing H, Bender R, et al. A general regression procedure for method transformation. Application of linear regression procedures for method comparison studies in clinical chemistry, Part III. J Clin Chem Clin Biochem 1988 Nov;26(11):783-790. | Linear regression |
y = 0.999x - 1.04 mg/L | r = 0.999 |
The sample concentrations were between 5.7 mg/L and 194 mg/L.
α1-Microglobulin (α1‑M) is a low molecular weight, pH stable glycoprotein. It has a molar mass of 30000 daltons and is synthesized by the hepatocytes and lymphocytes. It is almost entirely filtered in the glomeruli with approximately 99.8 % of the reabsorption and catabolism taking place in the proximal tubules.
Increased excretion of α1‑microglobulin in tubular proteinuria is indicative of reduced tubular reabsorption under normal glomerular filtration conditions. This form of proteinuria is typical for chronic interstitial nephropathy and for acute and chronic tubular damage caused by endogenous and exogenous tubular toxins. In renal failure, the plasma levels of this microprotein increase from an early stage. The resultant protein hyperfiltration in the residual nephron causes increased renal excretion as reabsorption capacity is exceeded (overflow proteinuria). α1‑Microglobulin can be used as a marker for the diagnosis of tubule‑interstitial nephropathy, for example, at an early stage or rule it out with a high degree of certainty; the detection limit is approximately 10‑20 mg/L (333‑666 nmol/L). Acute and chronic forms of tubular insufficiency (all forms of primary and secondary Fanconi syndrome), heavy metal intoxication, nephrotoxic side‑effects of pharmaceuticals, and rejection reactions following kidney transplantation can also be excluded.
R1 | Glycine buffer: 170 mmol/L, pH 7.0; NaCl: 1.1 mol/L; preservative |
R3 | Latex particles coated with anti‑human α1‑microglobulin antibodies (rabbit): 0.2‑0.3 %; glycine buffer: 150 mmol/L, pH 7.3; NaCl: 90 mmol/L; preservative |
R1 is in position B and R3 is in position C.
For professional in vitro diagnostic use.
Exercise the normal precautions required for handling all laboratory reagents.
Disposal of all waste material should be in accordance with local guidelines.
Safety data sheet available for professional user on request.
For quality control, use control materials as listed in the “Order information” section. In addition, other suitable control material can be used.
The control intervals and limits should be adapted to each laboratory’s individual requirements. Values obtained should fall within the defined limits. Each laboratory should establish corrective measures to be taken if values fall outside the defined limits.
Follow the applicable government regulations and local guidelines for quality control.
For specimen collection and preparation only use suitable tubes or collection containers.
Only the specimens listed below were tested and found acceptable.
Urine
The sample types listed were tested with a selection of sample collection tubes that were commercially available at the time of testing, i.e. not all available tubes of all manufacturers were tested. Sample collection systems from various manufacturers may contain differing materials which could affect the test results in some cases. When processing samples in primary tubes (sample collection systems), follow the instructions of the tube manufacturer.
Centrifuge samples containing precipitates before performing the assay.
See the limitations and interferences section for details about possible sample interferences.
Stability: | 5 days at 15‑25 °C 4 weeks at 2‑8 °C 3 months at ~(-70) °C |
Reagent to measure A1M Levels in human urine samples.
Immunoturbidimetric assay
Anti‑α1‑microglobulin antibodies sensitized to latex particles react with antigen in the sample to form an antigen/antibody complex which, after agglutination, can be determined turbidimetrically. This agglutination is detected as an absorbance change, with the magnitude of the change being proportional to the quantity of A1M in the sample. The actual concentration is determined by interpolation from a calibration curve prepared from calibrators of known concentration.
5.0‑200 mg/L
Limit of Blank | = 2 mg/L |
Limit of Detection | = 3.5 mg/L |
Limit of Quantitation | = 5 mg/L |
These data were generated on COBAS INTEGRA 400 plus based on the Clinical and Laboratory Standards Institute (CLSI) Protocol EP17‑A2. The precision goal for the Limit of Quantitation was a CV % of less than 16 %.
2nd morning urine:
Each laboratory should investigate the transferability of the expected values to its own patient population and if necessary determine its own reference ranges.
Criterion: deviation from initial value: ≤ 20 mg/L: ≤ ± 2 mg/L, > 20 mg/L: ≤ ± 10 %
Hemolysis:
Urea: No significant interference from urea up to a concentration of 2700 mmol/L.
Drugs:
High‑dose hook effect: No false result occurs up to a α1‑microglobulin concentration of 500 mg/L.
For diagnostic purposes, the results should always be assessed in conjunction with the patient’s medical history, clinical examination and other findings.
ACTION REQUIRED
Special Wash Programming: The use of special wash steps is mandatory when certain test combinations are run together on COBAS INTEGRA analyzers. Refer to the CLEAN Method Sheet for further instructions and for the latest version of the Extra wash cycle list.
Where required, special wash/carry-over evasion programming must be implemented prior to reporting results with this test.
|
| Analyzer(s) on which cobas c pack(s) can be used | |
08944539190 | α1-Microglobulin (100 tests) | System‑ID 07 7627 0 | COBAS INTEGRA 400 plus |
08944474190 | α1-Microglobulin Calibrator Set (5 × 1 mL) | System‑ID 07 7628 9 | |
03121313122 | Precinorm PUC (4 × 3 mL) | System‑ID 07 6756 5 | |
03121291122 | Precipath PUC (4 × 3 mL) | System‑ID 07 6757 3 | |
20756350322 | NaCl Diluent 9 % (50 mL) | System‑ID 07 5635 0 |
For COBAS INTEGRA 400 plus analyzers:
A1MGU: test ID: 0‑299
Ready for use
Measuring mode | Absorbance |
Abs. calculation mode | Endpoint |
Reaction mode | R1-S-SR |
Reaction direction | Increase |
Wavelength A/B | 583 |
Calc. first/last | 35/65 |
Typical prozone effect | > 500 mg/L |
Antigen excess check | No |
Unit | mg/L |
Diluent (H2O) | ||
R1 | 100 µL | - |
Sample | 10 µL | - |
SR | 33 µL | 5 |
Total volume | 148 µL |
Shelf life at 2‑8 °C | See expiration date on cobas c pack label | |
COBAS INTEGRA 400 plus system | ||
On-board in use at 10‑15 °C | 12 weeks |
Calibrators | S1: H2O S2‑S6: α1‑Microglobulin Calibrator Set |
Calibration mode | Spline |
Calibrator dilution ratio | 1:10, performed automatically by the instrument |
Calibration replicate | Duplicate recommended |
Calibration interval | Each lot and as required following quality control procedures |
Calibration interval may be extended based on acceptable verification of calibration by the laboratory.
The assigned α1‑Microglobulin values are:
Zerocalibrator: H2O = 0.0 mg/L
α1‑Microglobulin Calibrator Set: 10, 25, 50,100, 200 mg/L
Traceability: This method has been standardized against an internal standard traceable to a nephelometric method.
Representative performance data on the analyzers are given below. Results obtained in individual laboratories may differ.
Precision was determined data using human samples and controls in an internal protocol with repeatability (n = 21) and intermediate precision (2 aliquots per run, 2 runs per day, 21 days). The following results were obtained.
Repeatability | Mean | SD | CV |
Precinorm PUC | 34.8 | 0.719 | 2.1 |
Precipath PUC | 108 | 0.950 | 0.9 |
Human urine 1 | 10.8 | 0.652 | 6.0 |
Human urine 2 | 14.7 | 0.590 | 4.0 |
Human urine 3 | 101 | 2.19 | 2.2 |
Intermediate precision | Mean | SD | CV |
Control Low | 13.7 | 0.591 | 4.3 |
Control High | 111 | 1.36 | 1.2 |
Human urine 1 | 5.34 | 0.649 | 12.1 |
Human urine 2 | 16.2 | 0.521 | 3.2 |
Human urine 3 | 107 | 1.62 | 1.5 |
α1‑Microglobulin values for urine samples obtained on a COBAS INTEGRA 400 plus analyzer (y) were compared with those determined using the corresponding reagent on a cobas c 501 analyzer (x).
Sample size (n) = 117
Passing/Bablok LREFBablok W, Passing H, Bender R, et al. A general regression procedure for method transformation. Application of linear regression procedures for method comparison studies in clinical chemistry, Part III. J Clin Chem Clin Biochem 1988 Nov;26(11):783-790. | Linear regression |
y = 1.018x − 0.832 mg/L | r = 0.999 |
The sample concentrations were between 5.60 mg/L and 194 mg/L.
α1-Microglobulin (α1‑M) is a low molecular weight, pH stable glycoprotein. It has a molar mass of 30000 daltons and is synthesized by the hepatocytes and lymphocytes. It is almost entirely filtered in the glomeruli with approximately 99.8 % of the reabsorption and catabolism taking place in the proximal tubules.
Increased excretion of α1‑microglobulin in tubular proteinuria is indicative of reduced tubular reabsorption under normal glomerular filtration conditions. This form of proteinuria is typical for chronic interstitial nephropathy and for acute and chronic tubular damage caused by endogenous and exogenous tubular toxins. In renal failure, the plasma levels of this microprotein increase from an early stage. The resultant protein hyperfiltration in the residual nephron causes increased renal excretion as reabsorption capacity is exceeded (overflow proteinuria). α1‑Microglobulin can be used as a marker for the diagnosis of tubule‑interstitial nephropathy, for example, at an early stage or rule it out with a high degree of certainty; the detection limit is approximately 10‑20 mg/L (333‑666 nmol/L). Acute and chronic forms of tubular insufficiency (all forms of primary and secondary Fanconi syndrome), heavy metal intoxication, nephrotoxic side‑effects of pharmaceuticals, and rejection reactions following kidney transplantation can also be excluded.
R1 | Glycine buffer: 170 mmol/L, pH 7.0; NaCl: 1.1 mol/L; preservative |
SR | Latex particles coated with anti‑human α1‑microglobulin antibodies (rabbit): 0.2‑0.3 %; glycine buffer: 150 mmol/L, pH 7.3; NaCl: 90 mmol/L; preservative |
R1 is in position B and SR is in position C.
For professional in vitro diagnostic use.
Exercise the normal precautions required for handling all laboratory reagents.
Disposal of all waste material should be in accordance with local guidelines.
Safety data sheet available for professional user on request.
For quality control, use control materials as listed in the “Order information” section. In addition, other suitable control material can be used.
The control intervals and limits should be adapted to each laboratory’s individual requirements. Values obtained should fall within the defined limits. Each laboratory should establish corrective measures to be taken if values fall outside the defined limits.
Follow the applicable government regulations and local guidelines for quality control.
For specimen collection and preparation only use suitable tubes or collection containers.
Only the specimens listed below were tested and found acceptable.
Urine
Centrifuge samples containing precipitates before performing the assay.
See the limitations and interferences section for details about possible sample interferences.
Stability: | 5 days at 15‑25 °C 4 weeks at 2‑8 °C 3 months at ~(-70) °C |
Reagent to measure A1M Levels in human urine samples.
Immunoturbidimetric assay
Anti‑α1‑microglobulin antibodies sensitized to latex particles react with antigen in the sample to form an antigen/antibody complex which, after agglutination, can be determined turbidimetrically. This agglutination is detected as an absorbance change, with the magnitude of the change being proportional to the quantity of A1M in the sample. The actual concentration is determined by interpolation from a calibration curve prepared from calibrators of known concentration.
5.0‑200 mg/L
No automatic re‑run defined. Samples exceeding the measuring range must be diluted manually with 0.9 % NaCl solution; e.g. 1:2.
Limit of Blank | = 1 mg/L |
Limit of Detection | = 2.5 mg/L |
Limit of Quantitation | = 5 mg/L |
These data were generated on cobas c 501 at Denka, based on the Clinical and Laboratory Standards Institute (CLSI) Protocol EP17‑A2. The precision goal for the Limit of Quantitation was a CV % of less than 16 %.
2nd morning urine:
Each laboratory should investigate the transferability of the expected values to its own patient population and if necessary determine its own reference ranges.
Criterion: deviation from initial value: ≤ 20 mg/L: ≤ ± 2 mg/L, > 20 mg/L: ≤ ± 10 %
Hemolysis:
Urea: No significant interference from urea up to a concentration of 2700 mmol/L.
High dose hook‑effect: No false result occurs up to an α1‑microglobulin concentration of 500 mg/L.
Drugs:
For diagnostic purposes, the results should always be assessed in conjunction with the patient’s medical history, clinical examination and other findings.
ACTION REQUIRED
Special Wash Programming: The use of special wash steps is mandatory when certain test combinations are run together on cobas c systems. The latest version of the carry‑over evasion list can be found with the NaOHD-SMS-SmpCln1+2-SCCS Method Sheets. For further instructions refer to the operator’s manual. cobas c 502 analyzer: All special wash programming necessary for avoiding carry‑over is available via the cobas link, manual input is required in certain cases.
Where required, special wash/carry‑over evasion programming must be implemented prior to reporting results with this test.
|
| Analyzer(s) on which cobas c pack(s) can be used | |
08944539190 | α1-Microglobulin (100 tests) | System‑ID 07 7627 0 | cobas c 311, cobas c 501/502 |
08944474190 | α1-Microglobulin Calibrator Set (5 × 1 mL) | Code 620‑625 | |
03121313122 | Precinorm PUC (4 × 3 mL) |
| |
03121291122 | Precipath PUC (4 × 3 mL) |
| |
04489357190 | Diluent NaCl 9 % (50 mL) | System‑ID 07 6869 3 |
For cobas c 311/501 analyzer:
A1MGU: ACN 696
For cobas c 502 analyzer:
A1MGU: ACN 8696
Ready for use
Assay type | 2‑Point End | ||
Reaction time / Assay points | 10 / 27‑57 | ||
Wavelength (sub/main) | 800/570 nm | ||
Reaction direction | Increase | ||
Units | mg/L | ||
Reagent pipetting | Diluent (H2O) | ||
R1 | 100 µL | – | |
R3 | 33 µL | – | |
Sample volumes | Sample | Sample dilution | |
Sample | Diluent (NaCl) | ||
Normal | 10 µL | 10 µL | 90 µL |
Decreased | 10 µL | 10 µL | 90 µL |
Increased | 10 µL | 10 µL | 90 µL |
Assay type | 2‑Point End | ||
Reaction time / Assay points | 10 / 40‑70 | ||
Wavelength (sub/main) | 800/570 nm | ||
Reaction direction | Increase | ||
Units | mg/L | ||
Reagent pipetting | Diluent (H2O) | ||
R1 | 100 µL | – | |
R3 | 33 µL | – | |
Sample volumes | Sample | Sample dilution | |
Sample | Diluent (NaCl) | ||
Normal | 10 µL | 10 µL | 90 µL |
Decreased | 10 µL | 10 µL | 90 µL |
Increased | 10 µL | 10 µL | 90 µL |
A1MGU | |
Shelf life at 2‑8 °C: | See expiration date on cobas c pack label. |
On‑board in use and refrigerated on the analyzer: | 12 weeks |
Diluent NaCl 9 % | |
Shelf life at 2‑8 °C: | See expiration date on cobas c pack label. |
On‑board in use and refrigerated on the analyzer: | 12 weeks |
Calibrators | S1: H2O S2‑S6: α1-Microglobulin Calibrator Set |
Calibration mode | Spline |
Calibration frequency | Full calibration |
Calibration interval may be extended based on acceptable verification of calibration by the laboratory.
Traceability: This method has been standardized against an internal standard traceable to a nephelometric method.
Representative performance data on the analyzers are given below. Results obtained in individual laboratories may differ.
Precision was determined data using human samples and controls in an internal protocol with repeatability (n = 21) and intermediate precision (2 aliquots per run, 2 runs per day, 21 days). The following results were obtained.
Repeatability | Mean | SD | CV |
Precinorm PUC | 43.7 | 0.360 | 0.8 |
Precipath PUC | 181 | 1.66 | 0.9 |
Human urine 1 | 6.90 | 0.266 | 3.9 |
Human urine 2 | 15.4 | 0.252 | 1.6 |
Human urine 3 | 97.3 | 2.12 | 2.2 |
Intermediate precision | Mean | SD | CV |
Control Low | 14.1 | 0.185 | 1.3 |
Control High | 109 | 1.37 | 1.3 |
Human urine 1 | 4.99 | 0.231 | 4.6 |
Human urine 2 | 15.0 | 0.357 | 2.4 |
Human urine 3 | 96.2 | 3.07 | 3.2 |
α1‑Microglobulin values for urine samples obtained on a COBAS INTEGRA 400 plus analyzer (y) were compared with those determined using the corresponding reagent on a cobas c 501 analyzer (x).
Sample size (n) = 117
Passing/Bablok LREFBablok W, Passing H, Bender R, et al. A general regression procedure for method transformation. Application of linear regression procedures for method comparison studies in clinical chemistry, Part III. J Clin Chem Clin Biochem 1988 Nov;26(11):783-790. | Linear regression |
y = 1.018x − 0.832 mg/L | r = 0.999 |
The sample concentrations were between 5.60 mg/L and 194 mg/L.
α1-Microglobulin (α1‑M) is a low molecular weight, pH stable glycoprotein. It has a molar mass of 30000 daltons and is synthesized by the hepatocytes and lymphocytes. It is almost entirely filtered in the glomeruli with approximately 99.8 % of the reabsorption and catabolism taking place in the proximal tubules.
Increased excretion of α1‑microglobulin in tubular proteinuria is indicative of reduced tubular reabsorption under normal glomerular filtration conditions. This form of proteinuria is typical for chronic interstitial nephropathy and for acute and chronic tubular damage caused by endogenous and exogenous tubular toxins. In renal failure, the plasma levels of this microprotein increase from an early stage. The resultant protein hyperfiltration in the residual nephron causes increased renal excretion as reabsorption capacity is exceeded (overflow proteinuria). α1‑Microglobulin can be used as a marker for the diagnosis of tubule‑interstitial nephropathy, for example, at an early stage or rule it out with a high degree of certainty; the detection limit is approximately 10‑20 mg/L (333‑666 nmol/L). Acute and chronic forms of tubular insufficiency (all forms of primary and secondary Fanconi syndrome), heavy metal intoxication, nephrotoxic side‑effects of pharmaceuticals, and rejection reactions following kidney transplantation can also be excluded.
R1 | Glycine buffer: 170 mmol/L, pH 7.0; NaCl: 1.1 mol/L; preservative |
R3 | Latex particles coated with anti‑human α1‑microglobulin antibodies (rabbit): 0.2‑0.3 %; glycine buffer: 150 mmol/L, pH 7.3; NaCl: 90 mmol/L; preservative |
R1 is in position B and R3 is in position C.
For professional in vitro diagnostic use.
Exercise the normal precautions required for handling all laboratory reagents.
Disposal of all waste material should be in accordance with local guidelines.
Safety data sheet available for professional user on request.
For quality control, use control materials as listed in the “Order information” section. In addition, other suitable control material can be used.
The control intervals and limits should be adapted to each laboratory’s individual requirements. Values obtained should fall within the defined limits. Each laboratory should establish corrective measures to be taken if values fall outside the defined limits.
Follow the applicable government regulations and local guidelines for quality control.
For specimen collection and preparation only use suitable tubes or collection containers.
Only the specimens listed below were tested and found acceptable.
Urine
The sample types listed were tested with a selection of sample collection tubes that were commercially available at the time of testing, i.e. not all available tubes of all manufacturers were tested. Sample collection systems from various manufacturers may contain differing materials which could affect the test results in some cases. When processing samples in primary tubes (sample collection systems), follow the instructions of the tube manufacturer.
Centrifuge samples containing precipitates before performing the assay.
See the limitations and interferences section for details about possible sample interferences.
Stability: | 5 days at 15‑25 °C 4 weeks at 2‑8 °C 3 months at ~(-70) °C |
Reagent to measure A1M Levels in human urine samples.
Immunoturbidimetric assay
Anti‑α1‑microglobulin antibodies sensitized to latex particles react with antigen in the sample to form an antigen/antibody complex which, after agglutination, can be determined turbidimetrically. This agglutination is detected as an absorbance change, with the magnitude of the change being proportional to the quantity of A1M in the sample. The actual concentration is determined by interpolation from a calibration curve prepared from calibrators of known concentration.
5.0‑200 mg/L
No automatic re‑run defined. Samples exceeding the measuring range must be diluted manually with 0.9 % NaCl solution; e.g. 1:2.
Limit of Blank | = 1 mg/L |
Limit of Detection | = 2.5 mg/L |
Limit of Quantitation | = 5 mg/L |
These data were generated on cobas c 503 at Denka, based on the Clinical and Laboratory Standards Institute (CLSI) Protocol EP17‑A2. The precision goal for the Limit of Quantitation was a CV % of less than 16 %.
2nd morning urine:
Each laboratory should investigate the transferability of the expected values to its own patient population and if necessary determine its own reference ranges.
Criterion: deviation from initial value: ≤ 20 mg/L: ≤ ± 2 mg/L, > 20 mg/L: ≤ ± 10 %
Hemolysis:
Urea: No significant interference from urea up to a concentration of 2700 mmol/L.
Drugs:
High‑dose hook effect: No false result occurs up to a α1‑Microglobulin concentration of 500 mg/L.
For diagnostic purposes, the results should always be assessed in conjunction with the patient’s medical history, clinical examination and other findings.
ACTION REQUIRED
Special Wash Programming: The use of special wash steps is mandatory when certain test combinations are run together on cobas c systems. All special wash programming necessary for avoiding carry-over is available via the cobas link. The latest version of the carry-over evasion list can be found with the NaOHD/SMS/SCCS Method Sheet for information. For further instructions refer to the operator’s manual.
|
| Analyzer(s) on which cobas c pack(s) can be used | |
08944555190 | α1-Microglobulin (200 tests) | System‑ID 2131 001 | cobas c 503 |
08944474190 | α1-Microglobulin Calibrator Set (5 × 1 mL) | Code 20620‑20625 | |
03121313122 | Precinorm PUC (4 × 3 mL) |
| |
03121291122 | Precipath PUC (4 × 3 mL) |
| |
08063494190 | Diluent NaCl 9 % (123 mL) | System‑ID 2906 001 |
For cobas c 503 analyzers:
A1MGU: ACN 21310
Ready for use
Assay type | 2‑Point End | ||
Reaction time / Assay points | 10 / 20‑34 | ||
Wavelength (sub/main) | 800/570 nm | ||
Reaction direction | Increase | ||
Units | mg/L | ||
Reagent pipetting | Diluent (H2O) | ||
R1 | 73 µL | – | |
R3 | 24 µL | – | |
Sample volumes | Sample | Sample dilution | |
Sample | Diluent (NaCl) | ||
Normal | 10 µL | 7.3 µL | 90 µL |
Decreased | 10 µL | 7.3 µL | 90 µL |
Increased | 10 µL | 7.3 µL | 90 µL |
A1MGU | |
Shelf life at 2‑8 °C: | See expiration date on cobas c pack label. |
On‑board in use and refrigerated on the analyzer: | 12 weeks |
Diluent NaCl 9 % | |
Shelf life at 2‑8 °C: | See expiration date on cobas c pack label. |
On‑board in use and refrigerated on the analyzer: | 26 weeks |
Calibrators | S1: H2O (Cal Code 20620) S2‑S6: α1-Microglobulin Calibrator Set (Cal Code 20621‑20625) |
Calibration mode | Spline |
Calibration frequency | Full calibration |
Calibration interval may be extended based on acceptable verification of calibration by the laboratory.
Traceability: This method has been standardized against an internal standard traceable to a nephelometric method.
Representative performance data on the analyzers are given below. Results obtained in individual laboratories may differ.
Precision was determined data using human samples and controls in an internal protocol with repeatability (n = 21) and intermediate precision (2 aliquots per run, 2 runs per day, 21 days). The following results were obtained.
Repeatability | Mean | SD | CV |
Precinorm PUC | 40.8 | 0.183 | 0.4 |
Precipath PUC | 161 | 0.816 | 0.5 |
Human urine 1 | 7.56 | 0.184 | 2.4 |
Human urine 2 | 19.5 | 0.228 | 1.2 |
Human urine 3 | 110 | 0.577 | 0.5 |
Intermediate precision | Mean | SD | CV |
Control Low | 40.2 | 0.402 | 1.0 |
Control High | 161 | 1.93 | 1.2 |
Human urine 1 | 7.38 | 0.212 | 2.9 |
Human urine 2 | 19.5 | 0.287 | 1.5 |
Human urine 3 | 109 | 0.889 | 0.8 |
α1‑Microglobulin values for urine samples obtained on a cobas c 503 analyzer (y) were compared with those determined using the corresponding reagent on a cobas c 501 analyzer (x).
Sample size (n) = 116
Passing/Bablok LREFBablok W, Passing H, Bender R, et al. A general regression procedure for method transformation. Application of linear regression procedures for method comparison studies in clinical chemistry, Part III. J Clin Chem Clin Biochem 1988 Nov;26(11):783-790. | Linear regression |
y = 0.940x - 0.294 mg/L | r = 0.999 |
The sample concentrations were between 5.6 mg/L and 194 mg/L.
α1-Microglobulin (α1‑M) is a low molecular weight, pH stable glycoprotein. It has a molar mass of 30000 daltons and is synthesized by the hepatocytes and lymphocytes. It is almost entirely filtered in the glomeruli with approximately 99.8 % of the reabsorption and catabolism taking place in the proximal tubules.
Increased excretion of α1‑microglobulin in tubular proteinuria is indicative of reduced tubular reabsorption under normal glomerular filtration conditions. This form of proteinuria is typical for chronic interstitial nephropathy and for acute and chronic tubular damage caused by endogenous and exogenous tubular toxins. In renal failure, the plasma levels of this microprotein increase from an early stage. The resultant protein hyperfiltration in the residual nephron causes increased renal excretion as reabsorption capacity is exceeded (overflow proteinuria). α1‑Microglobulin can be used as a marker for the diagnosis of tubule‑interstitial nephropathy, for example, at an early stage or rule it out with a high degree of certainty; the detection limit is approximately 10‑20 mg/L (333‑666 nmol/L). Acute and chronic forms of tubular insufficiency (all forms of primary and secondary Fanconi syndrome), heavy metal intoxication, nephrotoxic side‑effects of pharmaceuticals, and rejection reactions following kidney transplantation can also be excluded.
R1 | Glycine buffer: 170 mmol/L, pH 7.0; NaCl: 1.1 mol/L; preservative |
R3 | Latex particles coated with anti‑human α1‑microglobulin antibodies (rabbit): 0.2‑0.3 %; glycine buffer: 150 mmol/L, pH 7.3; NaCl: 90 mmol/L; preservative |
R1 is in position B and R3 is in position C.
For professional in vitro diagnostic use.
Exercise the normal precautions required for handling all laboratory reagents.
Disposal of all waste material should be in accordance with local guidelines.
Safety data sheet available for professional user on request.
For quality control, use control materials as listed in the “Order information” section. In addition, other suitable control material can be used.
The control intervals and limits should be adapted to each laboratory’s individual requirements. Values obtained should fall within the defined limits. Each laboratory should establish corrective measures to be taken if values fall outside the defined limits.
Follow the applicable government regulations and local guidelines for quality control.
For specimen collection and preparation only use suitable tubes or collection containers.
Only the specimens listed below were tested and found acceptable.
Urine
The sample types listed were tested with a selection of sample collection tubes that were commercially available at the time of testing, i.e. not all available tubes of all manufacturers were tested. Sample collection systems from various manufacturers may contain differing materials which could affect the test results in some cases. When processing samples in primary tubes (sample collection systems), follow the instructions of the tube manufacturer.
Centrifuge samples containing precipitates before performing the assay.
See the limitations and interferences section for details about possible sample interferences.
Stability: | 5 days at 15‑25 °C 4 weeks at 2‑8 °C 3 months at ~(-70) °C |
α1-Microglobulin
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