ACCUBIND NEONATAL T4 MICROPLATE EIA, MODEL 2625-300
Device Facts
| Record ID | K030860 |
|---|---|
| Device Name | ACCUBIND NEONATAL T4 MICROPLATE EIA, MODEL 2625-300 |
| Applicant | Monobind |
| Product Code | KLI · Clinical Chemistry |
| Decision Date | Aug 22, 2003 |
| Decision | SESE |
| Submission Type | Traditional |
| Regulation | 21 CFR 862.1700 |
| Device Class | Class 2 |
| Attributes | Pediatric |
Indications for Use
This test is intended for the quantitative determination of Thyroxine (T4) in blood specimens dried on filter paper for screening newborns for congenital (neonatal) hypothyroidism.
Device Story
AccuBind™ Neo-Natal T4 Microplate EIA is an enzyme immunoassay (EIA) for quantitative T4 measurement in dried blood spot specimens. Used in clinical laboratories for neonatal screening programs to detect congenital hypothyroidism. Device utilizes microplate-based immunoassay technology; samples are processed to extract T4, which competes with enzyme-labeled T4 for binding sites on antibody-coated microplate wells. After incubation and washing, substrate addition produces color intensity inversely proportional to T4 concentration. Results are measured via spectrophotometry. Healthcare providers use these quantitative results to identify newborns requiring further diagnostic follow-up for hypothyroidism, facilitating early intervention.
Clinical Evidence
No clinical data provided; substantial equivalence established via bench testing and performance validation of the immunoassay system.
Technological Characteristics
Solid-phase enzyme immunoassay (EIA). Microplate format. Requires microplate reader (450nm/620nm). Uses S&S 903 filter paper for dried blood spots. Non-radioactive detection.
Indications for Use
Indicated for quantitative determination of Thyroxine (T4) in dried blood spot specimens for screening newborns for congenital (neonatal) hypothyroidism.
Regulatory Classification
Identification
A total thyroxine test system is a device intended to measure total (free and protein bound) thyroxine (thyroid hormone) in serum and plasma. Measurements obtained by this device are used in the diagnosis and treatment of thyroid diseases.
Special Controls
*Classification.* Class II (special controls). The device is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 862.9.
Related Devices
- K972974 — ACCUWELL T4-EIA · Neometrics, Inc. · Oct 6, 1997
- K951014 — ISOLAB'S T4 TEST KIT · Isolab, Inc. · Oct 18, 1996
- K072458 — GBI TSH NEONATAL SCREENING KIT · Golden Bridge International, Inc. · Apr 10, 2008
Submission Summary (Full Text)
{0}
510(k) SUBSTANTIAL EQUIVALENCE DETERMINATION
DECISION SUMMARY
DEVICE ONLY TEMPLATE
A. 510(k) Number: k030860
B. Analyte: T4
C. Type of Test: Microwell EIA for the quantitation of Thyroxine in neonates.
D. Applicant: Monobind, Inc
E. Proprietary and Established Names: AccuBind™ Neo-Natal T4 Microplate EIA
F. Regulatory Information:
1. Regulation section: 21 CFR 862.1700
2. Classification: Class II
3. Product Code: KLI
4. Panel: 75
G. Intended Use:
1. Intended use(s): This test is intended for the quantitative determination of Thyroxine (T4) in blood specimens dried on filter paper for screening newborns for congenital (neonatal) hypothyroidism.
2. Indication(s) for use: This test is intended for the quantitative determination of Thyroxine (T4) in blood specimens dried on filter paper for screening newborns for congenital (neonatal) hypothyroidism.
3. Special condition for use statement(s): none stated
4. Special instrument Requirements: Microplate reader capable of absorbance readings at 450nm and 620nm
H. Device Description: Monobind’s Neo-Natal T4 EIA is a solid phase Enzyme Immunoassay system. Calibrators and controls are included in the test kit. Calibrators, controls and patient samples are dried onto supplied filter paper. Values are established using dried blood references for calibrators. Since measurement is not done via irradiation no radioactive waste is collected.
I. Substantial Equivalence Information:
1. Predicate device name(s): Delfia Neonatal Thyroxine Kit
{1}
Page 2 of 5
2. Predicate K number(s): k943416
| Comparison with predicate: | | |
| --- | --- | --- |
| Item | Device | Predicate |
| Intended for the quantitative determination of Thyroxine (T4) in blood specimens dried of filter paper for screening newborns for congenital (neonatal) hypothyroidism. | Yes | Yes |
| Uses filter paper to blot and dry sample | Yes | Yes |
| EIA Assay | Yes | No |
| Uses radioactive labeled T4 as indicator | No | Yes |
| Includes calibrators and controls | Yes | Yes |
J. Standard/Guidance Document Referenced (if applicable): None Stated
K. Test Principle: The methodology used in the Monobind T4 is EIA (Enzyme Immunoassay)
L. Performance Characteristics (if/when applicable):
1. Analytical performance:
a. Precision/Reproducibility: The within and between run assays of the Neonatal T4 Microplate EIA test system were determined by analysis on three different levels of dried blood controls. The number, mean values, standard deviation and coefficient of variation for each control are listed below. This data represents ten experiments run in duplicate over a ten day period.
Within Assay Precision (values in ug/dL)
| Sample | N | X | S.D. | C.V. |
| --- | --- | --- | --- | --- |
| Low | 20 | 2.4 | 0.26 | 10.7% |
| Normal | 20 | 8.1 | 0.37 | 4.6% |
| High | 20 | 21.1 | 1.69 | 8.02% |
Between Assay Precision (values in ug/dL)
| Sample | N | X | S.D. | C.V. |
| --- | --- | --- | --- | --- |
| Low | 10 | 2.5 | 0.26 | 10.5% |
| Normal | 10 | 8.2 | 0.47 | 5.8% |
| High | 10 | 21.0 | 1.51 | 7.2% |
{2}
Page 3 of 5
b. Linearity/ assay reportable range:
Two individual blood units were drawn from apparently normal, healthy subjects. The blood samples were stripped of T4 by washing red cells twice with 50 mM PBS. The serum collected was supplemented with T4/T3 stripped human serum. Hematocrit was adjusted to 0.52. An aliquot of T4 '0' blood sample was spiked with 100 µg/dL of Thyroxine. This stock was used for making further dilutions. All the diluted preparations were spotted on the S&S 903 filter paper and dried. The blood dots taken from those were assayed according to Monobind product insert 2625-300 for Neo-T4 EIA. The summarized results are given here below:
| | Concentration (μg/dL) | | % Recovery |
| --- | --- | --- | --- |
| Sample I.D. | Expected (E) | Observed (O) | O/E*100 |
| A | 0.0 | 0.0 | 100.0 |
| B | 0.312 | 0.253 | 81.1 |
| C | 0.625 | 0.671 | 107.4 |
| D | 1.250 | 1.313 | 105.1 |
| E | 2.500 | 2.484 | 99.4 |
| F | 5.000 | 4.906 | 98.1 |
| G | 10.000 | 10.330 | 103.3 |
| H | 20.000 | 20.920 | 104.6 |
| I | 30.000 | 28.780 | 95.9 |
| J | 40.000 | 41.200 | 103.0 |
| K | 50.000 | 48.110 | 96.2 |
| L | 60.000 | 55.000 | 91.6 |
| M | 70.000 | 59.000 | 84.2 |
| N | 80.000 | 64.000 | 80.0 |
| O | 90.000 | 61.000 | 67.8 |
| P | 100.000 | 61.000 | 61.0 |
Based on the above study Monobind Neo-T4 was observed to be linear from 0.3 µg/dL to 50 µg/dL. Samples (Concentrations) A-B & L-P were deleted from the range.
c. Traceability (controls, calibrators, or method): CDC neonatal control program for monitoring neonatal thyroid assays.
d. Detection limit: Two individual blood units were drawn from apparently normal, healthy subjects. The blood samples were stripped of T4 by washing red cells twice with 50 mM PBS. The serum collected was supplemented with T4/T3 stripped human serum. Hematocrit was adjusted to 0.52. An aliquot of T4 '0' blood sample was spiked with 100 µg/dL of Thyroxine. All the above preparations were spotted on the S&S 903 filter paper and dried. The blood dots taken from those were assayed
{3}
Page 4 of 5
according to Monobind product insert 2625-300 for Neo-T4 EIA. Based on the above study Monobind Neo-T4 was observed to be linear from 0.3 µg/dL to 50 µg/dL. This linear limit indicates the assay detection cutoff.
e. Analytical specificity: No apparent effect of increased hemoglobin was seen for the assay. No effects were noted when pure thyroid binding globulin, phenytoin or phenylbutazone were added to samples and assayed.
f. Assay cut-off: Based on 242 specimens taken from healthy infants the normal range for healthy neonates is assigned at 8.2 – 19.7 µg/dL. The results showed a mean of 14.0 µg/dL and a 10% cut off value of 10.3 µg/dL.
2. Comparison studies:
a. Method comparison with predicate device: The Accubind was compared to the Delfia Neonatal Thyroxine Kit. Biological specimens from infants were used. (The values ranged from 0.5 µg/dL – 45 µg/dL). A total of 370 specimens were used. Least square regression and the correlation coefficient were computed for this comparison with the predicate method. The data obtained is provided below:
| Method | Mean(x) | Equation |
| --- | --- | --- |
| Monobind EIA “Y” | 15.63 | Y=0.6044+0.9413*X |
| Predicate RIA (X) | 15.96 | |
b. Matrix comparison: NA
3. Clinical studies:
a. Clinical sensitivity: No Clinical studies were provided to determine clinical sensitivity
b. Clinical specificity: No Clinical studies were provided to determine clinical specificity
c. Other clinical supportive data (when a and b are not applicable): none stated
4. Clinical cut-off: Based on 242 specimens taken from healthy infants the normal range for healthy neonates is assigned at 8.2 – 19.7 µg/dL. The results showed a mean of 14.0 µg/dL and a 10% cut off value of 10.3 µg/dL.
{4}
Page 5 of 5
5. Expected values/Reference range: Based on 242 specimens taken from healthy infants the normal range for healthy neonates is assigned at 8.2 – 19.7 ug/dL. The results showed a mean of 14.0 ug/dL and a 10% cut off value of 10.3 ug/dL. The manufacturer further states: “It is important to keep in mind that any normal range establishment is dependant upon a multiplicity of factors like the specificity of method, the locale, the population tested and the precision of the method in the hands of technicians. For neonatal screening age, weight, and prematurity of the infant play a major role as well. For these reasons each laboratory should depend upon the range of expected values established by the manufacturer only until in house ranges can be determined.”
M. Conclusion: Based upon the information provided, I recommend that the AccuBind™ Neo-Natal T4 Microplate EIA Kit be found substantially equivalent with similar predicate devices as defined in 21 CFR 862.1700.
