Inter-laboratory reproducibility between Tokyo Public Health Laboratory and Verinata Health Inc.
Inter-laboratory reproducibility refers to the accuracy when analyzing multiple samples repeatedly taken from homogeneous specimens, but with the variation of testing laboratories. This article summarizes the experimental results of inter-laboratory reproducibility conducted by the Tokyo Metropolitan Institute of Public Health and Verinata Health Inc. in the United States, and discloses the quality of NIPT tests provided by the Tokyo Metropolitan Institute of Public Health.
Precision
The precision of an analytical method refers to the degree of agreement among a series of measurements obtained under specified conditions for multiple samples collected multiple times from homogeneous specimens. There are three levels of precision: repeatability, intermediate precision, and reproducibility.
Reproducibility
Inter-laboratory reproducibility refers to the accuracy of measurements conducted between different facilities.
In this article, we summarize the results of inter-laboratory reproducibility conducted by our Tokyo Metropolitan Institute of Public Health and Verinata Health Inc. in the United States.
To assess the analytical validity of our NIPT (Non-Invasive Prenatal Testing) for trisomy 13, 18, and 21, we conducted tests using the same samples at both the Tokyo Metropolitan Institute of Public Health and Verinata Health Inc. The testing period spanned approximately two years, from May 2019 to March 2021, and involved a total of 105 samples.
The conditions of the test are as follows:
- Average age of the pregnant women: 35.7 years (standard deviation 4.7 years)
- Average gestational age of the pregnant women: 12.6 weeks (standard deviation 3.2 weeks)
- Average BMI of the pregnant women: 20.7 (standard deviation 2.4)）
- One of the negative control samples and one trisomy 13 positive sample were tested simultaneously at both testing facilities.
- Nine other positive samples were initially identified as positive at the Tokyo Metropolitan Institute of Public Health but were shipped to the United States with frozen plasma, with Verinata Health Inc. conducting the testing on-site while keeping the results blinded.
The results are summarized in the table below.
| number of cases of TL | the same result as VH | |
|---|---|---|
| negative | 95 | 95 |
| 21 trisomy | 4 | 4 |
| 18 trisomy | 3 | 3 |
| 13 trisomy | 3 | 3 |
※TL；Tokyo Lab. , VH；Verinata Health Inc
Out of a total of 105 samples, including 95 negative samples, 4 trisomy 21 positive samples, 3 trisomy 18 positive samples, and 3 trisomy 13 positive samples, all results were consistent between the two facilities (resulting in a 100% concordance rate for this test).
The average fetal fraction, calculated simultaneously, was 10.4 (standard deviation 3.5) at the Tokyo Metropolitan Institute of Public Health and 9.5 (standard deviation 3.7) at Verinata Health Inc. These results also demonstrate good consistency.
These findings suggest that the NIPT (Non-Invasive Prenatal Testing) provided by the Tokyo Metropolitan Institute of Public Health can offer testing comparable to that of Verinata Health Inc., a leading provider of non-invasive testing for fetal chromosomal abnormalities.