The assay is to be used to detect antibodies in a single serum specimen. The results of the assay are to be used as an aid to the diagnosis of microscopic polyangiitis. FOR IN VITRO DIAGNOSTIC USE.

Device Description

The MPO EIA test is an enzyme-linked immunosorbent assay (EIA) for the detection and semi-quantitation of antibodies to myeloperoxidase in human sera. The MPO EIA test is an enzyme linked immunosorbent assay to detect IgG, IgM, and IgA antibodies to myeloperoxidase. Purified MPO is attached to a solid phase microtiter well. Diluted test sera is added to each well. If the antibodies are present that recognize the antigen they will bind to the antigen in the well. After incubation the wells are washed to remove unbound antibody. An enzyme labeled anti-human IgG. M. A is added to each well. If antibody is present it will bind to the antibody attached to the antigen on the well. After incubation the wells are washed to remove unbound conjugate. A substrate solution is added to each well. If enzyme is present the substrate will undergo a color change. After an incubation period the reaction is stopped and the color intensity is measured photometrically, producing an indirect measurement of specific antibody in the patient specimen.

AI/ML Overview

Here's an analysis of the provided text regarding the MPO EIA Test Kit, structured according to your request:

In this document summary, the "device" refers to the MPO EIA Test Kit. The "acceptance criteria" can be inferred from the performance characteristics reported, as these values are presented as demonstrating the device's acceptable function. The primary study described is a comparative analysis against IFA and an alternate ELISA, as well as a clinical sensitivity and specificity study.

Acceptance Criteria and Reported Device Performance

Performance Characteristic	Acceptance Criteria (Implied)	Reported Device Performance
Relative Sensitivity (vs. IFA)	High sensitivity for detecting ANCA	95.0% (95% CI: 85.3% - 100%)
Relative Specificity (vs. IFA)	High specificity for ANCA	100% (95% CI: 98.6% - 100%)
Relative Agreement (vs. IFA)	High agreement with IFA	99.6% (95% CI: 98.7% - 100%)
Precision (Coefficient of Variation, C.V.)	C.V.'s of less than 15%	Intra-Assay: Ranges from 2.66% to 59.49% (Samples 1-9 across 3 assays). Most samples show C.V. < 15%, but samples 5, 6, and 7 exceed this. Inter-Assay: Ranges from 5.73% to 46.08%. Most samples show C.V. < 15%, but samples 5, 6, and 7 exceed this.
Linearity (Semi-quantitation)	Assay demonstrates linearity (Implied: high R-squared for linear regression)	Demonstrated: R-squared values for 5 sera ranged from 0.992 to 0.999 when comparing MPO index to log2 dilution.
Cross-Reactivity	No cross-reactivity with common autoantibodies	All 21 sera with various autoantibodies (SM, RNP, Ro, La, SCL-70, Jo-1, dsDNA) yielded negative MPO Index Values, indicating no cross-reactivity.
Clinical Sensitivity (Microscopic Polyangiitis)	(No explicit numerical target given)	45.0% (95% CI: 29.3% - 60.7%)
Clinical Specificity (Wegener's Granulomatosis)	(No explicit numerical target given)	95.0% (95% CI: 88.1% - 100%)
Clinical Specificity (Other Autoimmune Sera)	(No explicit numerical target given)	100% (95% CI: 85.9% - 100%)
Clinical Specificity (Normals)	(No explicit numerical target given)	99.4% (95% CI: 98.0% - 100%)

Note on Precision Acceptance Criteria: The document states, "With proper technique the user should obtain C.V.'s of less than 15%." While most reported C.V. values for samples 1-4, 8, and 9 meet this, samples 5, 6, and 7 consistently show C.V.s significantly above 15% in both intra- and inter-assay measurements, indicating that this acceptance criterion was not met for all tested samples. This discrepancy is important for a full safety and effectiveness evaluation.

Study Details:

Sample sizes used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective):
- Relative Sensitivity and Specificity (vs. IFA):
  - Test Set Size: 235 sera (40 from patients with Wegener's granulomatosis, 40 from patients with microscopic polyangiitis, and 155 from normals). However, the table data on page 2 shows a total of 233 sera evaluated against IFA.
  - Data Provenance: Not explicitly stated, but the mention of "various ages, gender, and geographical areas" for normals suggests a broader, though unspecified, geographical origin. The data appears retrospective, as it's a collection of existing patient sera.
- Comparison to Alternate ELISA:
  - Test Set Size: 233 sera. This is the "same group of clinical sera" as used for the IFA comparison.
  - Data Provenance: Same as above – not explicitly stated, likely retrospective.
- Clinical Sensitivity and Specificity:
  - Test Set Size: 254 sera (40 Microscopic polyangiitis, 40 Wegener's granulomatosis, 21 Other autoimmune sera, 153 Normals). This appears to be a grouped analysis of the "clinical sera and the potentially cross-reactive sera".
  - Data Provenance: Not explicitly stated, likely retrospective.
- Precision:
  - Test Set Size: 9 different sera, each tested 11 times on 3 different assays (for a total of 33 tests per serum for inter-assay precision).
  - Data Provenance: Not specified.
- Linearity:
  - Test Set Size: 5 positive sera.
  - Data Provenance: Not specified.
- Cross-Reactive Data:
  - Test Set Size: 21 sera with high levels of antibodies to potentially cross-reactive antigens.
  - Data Provenance: Not specified.
Number of experts used to establish the ground truth for the test set and the qualifications of those experts (e.g. radiologist with 10 years of experience):
- The "ground truth" for the primary study (Sensitivity and Specificity) is established by IFA (Immunofluorescence Assay) for ANCA detection. For clinical performance, it's based on patient diagnoses (Wegener's granulomatosis, microscopic polyangiitis, other autoimmune diseases, normals).
- The document does not specify the number or qualifications of experts who performed the IFA tests or established the clinical diagnoses.
Adjudication method (e.g. 2+1, 3+1, none) for the test set:
- There is no mention of an adjudication method used for either the IFA results or the clinical diagnoses. The IFA is presented as the reference standard itself.
If a multi reader multi case (MRMC) comparative effectiveness study was done, If so, what was the effect size of how much human readers improve with AI vs without AI assistance:
- No, an MRMC comparative effectiveness study was not done. This device is an in-vitro diagnostic (IVD) test kit, not an AI-powered image analysis tool requiring human readers. The comparison is between different assay methodologies (ELISA vs. IFA, and MPO ELISA vs. Alternate ELISA).
If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:
- Yes, this is an inherent standalone performance study. The MPO EIA Test Kit is an in vitro diagnostic assay. Its performance (sensitivity, specificity, precision, linearity, cross-reactivity) is measured by its chemical and biological reactions, without human interpretation of complex images or data needing AI assistance. The results (optical density, index value) are read by a photometer, and interpretation rules (e.g., Index ≥ 1.10 for Positive) are applied directly.
The type of ground truth used (expert consensus, pathology, outcomes data, etc):
- For Relative Sensitivity/Specificity: The primary ground truth is the IFA (Immunofluorescence Assay) result for ANCA.
- For Clinical Sensitivity/Specificity: The ground truth is based on clinical diagnoses (e.g., microscopic polyangiitis, Wegener's granulomatosis, other autoimmune diseases, and "normals"). The method of confirming these diagnoses (e.g., pathology, clinical criteria, etc.) is not detailed.
The sample size for the training set:
- This document describes performance studies, which are typically conducted on test sets. There is no mention of a separate "training set" for an algorithm, as this device is a laboratory assay kit and not an AI/ML model. The development of such a kit would involve initial research and optimization, but standard "training set" terminology doesn't directly apply here in the context of AI.
How the ground truth for the training set was established:
- As there's no explicitly defined "training set" in the AI/ML sense, this question is not applicable. The development and optimization of the MPO EIA Test Kit would have involved various experimental runs and validations, but the details of those processes are not provided in this summary of safety and effectiveness.

Summary

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K961765

Summary of Safety and Effectiveness Information MPO EIA Test Kit

I. Immuno Probe Inc. 1306 Bailes Lane, Suite F Frederick. Maryland 21701 Contact person William Boteler Telephone: 301-695-7920 Date of preparation: June 28, 1996
II. Description of Device

The MPO EIA test is an enzyme-linked immunosorbent assay (EIA) for the detection and semi-quantitation of antibodies to myeloperoxidase in human sera. The assay is to be used to detect antibodies in a single serum specimen. The results of the assay are to be used as an aid to the diagnosis of microscopic polyangiitis. FOR IN VITRO DIAGNOSTIC USE.

The MPO EIA test is an enzyme linked immunosorbent assay to detect IgG, IgM, and IgA antibodies to myeloperoxidase. Purified MPO is attached to a solid phase microtiter well. Diluted test sera is added to each well. If the antibodies are present that recognize the antigen they will bind to the antigen in the well. After incubation the wells are washed to remove unbound antibody. An enzyme labeled anti-human IgG. M. A is added to each well. If antibody is present it will bind to the antibody attached to the antigen on the well. After incubation the wells are washed to remove unbound conjugate. A substrate solution is added to each well. If enzyme is present the substrate will undergo a color change. After an incubation period the reaction is stopped and the color intensity is measured photometrically, producing an indirect measurement of specific antibody in the patient specimen.

III. Predicate Device

The MPO EIA test is substantially equivalent to IFA. Equivalence is demonstrated by the following comparative results

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Performance Characteristics

Sensitivity and Specificity - The MPO ELISA kit was evaluated relative to IFA for ANCA. Forty sera were from patients diagnosed with Wegener's granulomatosis. Forty sera were from patients diagnosed with microscopic polyangiitis. One hundred and fifty five sera were from normals with various ages, gender, and geographical areas. The data in Table 1 summarizes the data. Note: the sensitivity and specificity relative to IFA will not be as high if random IFA positive sera are selected due to other disease states causing ANCA patterns not associated with MPO.

Table 1 Sensitivity and Specificity of the MPO ELISA Kit Relative to IFA

	PositiveIndex ≥ 1.10	Equivocal0.91-1.09	Total
IFA	Positive	19*	1**	20
	Negative	0	213***	213
	Total	19	214	233

MPO ELISA

Relative Sensitivity = 19/20 = 95.0%	95% Confidence interval = 85.3% - 100%
Relative Specificity = 213/213 = 100%	95% Confidence interval = 98.6% - 100%
Relative Agreement= 232/233 = 99.6%	95% Confidence interval = 98.7% - 100%

The 95% confidence intervals were calculated using the normal method. The 95% confidence interval for Specificity was calculated assuming one false positive

Thirteen sera were patients diagnosed with microscopic polyangitis with a p-ANCA pattern. One sera was from a patient diagnosed with Wegeners granulomatosis with a p-ANCA pattern. One sera was from a patient diagnosed with Wegeners granulomatosis with a c-ANCA pattern. Four sera were patients diagnosed with microscopic polyangiitis, that were positive for ANA thus making the p-ANCA pattern impossible to read.

** One serum was from a patient diagnosed with microscopic polyangiitis with a p-ANCA pattern.

*** Sixty serum were from patients diagnosed with microscopic polyangiitis or Wegeners granulomatosis that had c-ANCA patterns or negative for ANCA. One hundred fifty three serum were from normals negative for ANCA.

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The same group of clinical sera were tested on an legally marketed ELISA device to determine the relative sensitivity and specificity to an alternate ELISA. The data in Table 2 summarizes the data.

Table 2 Comparison of MPO ELISA and ELISA

MPO ELISA

		PositiveIndex ≥ 1.10	Negative≤ 90	Total
	Positive	6	1**	7
AlternateELISA	Equivocal	4	7	11
	Negative	11*	204	215
	Total	21	212	233

Relative Sensitivity = 6/7 = 85.7% 95% Confidence interval = 59.3% - 100% 95% Confidence interval = 91.9% - 97.9% Relative Specificity = 204/215 = 94.9% Relative Agreement= 210/222 = 94.6% 95% Confidence interval = 91.6% - 97.6%

The 95% confidence intervals were calculated using the normal method.

Eight serum were from patients diagnosed with Microscopic polyangiitis. Two serum were from patients diagnosed with Wegeners Granulomatosis One serum was a normal.

** The serum was a normal.

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The clinical sera and the potentially cross-reactive sera were grouped and the clinical sensitivity and specificity of the MPO ELISA assay was calculated The data in Table 3 summarizes the data.

Clinical Sensitivity and Specificity of MPO ELISA Table 3

MPO ELISA

	PositiveIndex ≥ 1.10	Negative≤ 90	Total
Microscopic polyangiitis	18	22	40
Wegener's granulomatosis	2	38	40
Other autoimmune sera	0	21	21
Normals	1	152	153
Total	20	233	254

Clinical Sensitivity Microscopic polyangiitis	= 18/40	= 45.0%
95% confidence interval	= 29.3 - 60.7%
Clinical Specificity Wegener's granulomatosis	= 38/40	= 95.0%
95% confidence interval	= 88.1 - 100%
Clinical Specificity Other autoimmune sera	= 21/21	= 100%
95% confidence interval	= 85.9 - 100%
Clinical Specificity Normals	= 152/153	= 99.4%
95% confidence interval	= 98.0 - 100%

The 95% confidence intervals were calculated using the normal method. The 95% confidence intervals for the clinical specificity for other autoimmune sera were calculated assuming one false positive.

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2. Precision

The precision of the MPO kit was determined by testing nine different sera eleven times each on three different assays. The data is summarized in Table 4. With proper technique the user should obtain C.V.'s of less than 15%.

Table 4

Assay 1 (n=11)			Assay 2 (n=11)			Assay 3 (n=11)			Inter Assay(n=33)
	X	S.D.	C.V	X	S.D.	C.V.	X	S.D.	C.V.	X	SD	CV
1	4.60	0.137	2.99%	4.39	0.222	5.06%	4.53	0.347	7.67%	4.5	0.258	5.73%
2	5.13	0.136	2.66%	4.97	0.236	4.74%	5.12	0.432	8.44%	5.08	0.295	5.81%
3	3.53	0.227	6.43%	3.21	0.217	6.75%	3.32	0.192	5.79%	3.36	0.248	7.38%
4	2.76	0.218	7.90%	2.51	0.338	13.45%	2.74	0.282	10.29%	2.67	0.297	11.13%
5	0.41	0.079	19.19%	0.37	0.067	17.92%	0.44	0.070	15.93%	0.41	0.076	18.58%
6	0.04	0.021	46.53%	0.05	0.017	35.78%	0.04	0.024	59.49%	0.04	0.020	46.08%
7	0.05	0.17	36.14%	0.05	0.018	38.94%	0.05	0.028	60.79%	0.05	0.021	45.24%
8	0.92	0.049	5.32%	0.84	0.054	6.42%	0.88	0.060	6.85%	0.88	0.063	7.14%
9	1.08	0.064	5.95%	0.94	0.055	5.91%	0.97	0.04	4.10%	0.97	0.094	9.67%

X = = Mean MPO Value S.D. = Standard Deviation C.V. = Coefficient of Variation

3. Linearity

The MPO index values were determined for serial twofold dilutions of five positive sera. The index values were compared to log2 of dilution by standard linear regression. The data in table #5 indicates that the assay is semi-quantitative.

	Table 5Linearity
Serum	Neat	l :2	1:4	1.8	1 16	1:32	1:64
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------	3.03	2.43	1.77	1.12	0 રો			0 999
୍ୟ	3.57	2.67	1.83	1 05	0 52			0.997
3	2.93	2.21	1.57	0 99	0 65			0 994
4	3.72	3.07	2.51	1.74	1 06	0.61		0 998
റ	4.32	3.97	3.52	2.82	2 06	1.31	0.77	0.992

Linear regression compared MPO ISR to log2 of dilution.

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4. Cross Reactive Data

Sera containing high level of antibodies to potentially cross reactive antigens were assayed on the MPO ELISA kit. The data in table 6 indicate that antibodies to alternate autoimmune antigens do not cross react with the MPO ELISA kit.

Table 6 Cross Reactive Data

Serum #	Antibody Specificity	MPO Index Value	Interpretation
1.	SM	0 15	-
2.	SM	0 36	-
3.	SM	0 23	-
4.	RNP	0 10	-
5.	RNP	0 17	-
6.	RNP	0 09	-
7.	Ro	0 12	-
8.	Ro	0 07	-
9.	Ro	0 09	-
10.	La	0 07	-
11.	La	0 07	-
12.	La	0 06	-
13.	Scl-70	0 10	-
14.	Scl-70	0 12	-
15.	Scl-70	0 08	-
16.	Jo-	0 09	-
17.	Jo-	0 10	-
18.	Jo-1	0 10	-
19.	dsDNA	0 22	-
20.	dsDNA	0 08	-
21	dsDNA	0 27	-

Regulation Number and Section

§ 866.5660 Multiple autoantibodies immunological test system.

(a)
Identification. A multiple autoantibodies immunological test system is a device that consists of the reagents used to measure by immunochemical techniques the autoantibodies (antibodies produced against the body's own tissues) in serum and other body fluids. Measurement of multiple autoantibodies aids in the diagnosis of autoimmune disorders (disease produced when the body's own tissues are injured by autoantibodies).(b)
Classification. Class II (performance standards).