[Histonet] IHC validations

[Joe Myers]

Dear Ms. Lucas:
Unfortunately, there is no specific CLIA standard that addresses the quantity of positive/negative specimens that should be tested during the procedure validation process.  As stated in the regulation excerpt shown below (section 2), it is up to each laboratory to establish its own ‘performance specifications’ for procedures that ate developed ‘in-house’, as nearly all IHC procedures are.

42 CFR  493.1253 Standard: Establishment and verification of performance specifications.
(a) Applicability. Laboratories are not required to verify or establish performance specifications for any test system used by the laboratory before April 24, 2003.
(b)
(1) Verification of performance specifications. Each laboratory that introduces an unmodified, FDA-cleared or approved test system must do the following before reporting patient test results:
(i) Demonstrate that it can obtain performance specifications comparable to those established by the manufacturer for the following performance characteristics:
(A) Accuracy.
(B) Precision.
(C) Reportable range of test results for the test system.
(ii) Verify that the manufacturer's reference intervals (normal values) are appropriate for the laboratory's patient population.
(2) Establishment of performance specifications. Each laboratory that modifies an FDA-cleared or approved test system, or introduces a test system not subject to FDAclearance or approval (including methods developed in-house and standardized methods such as text book procedures), or uses a test system in which performance specifications are not provided by the manufacturer must, before reporting patienttest results, establish for each test system the performance specifications for the following performance characteristics, as applicable:
(i) Accuracy.
(ii) Precision.
(iii) Analytical sensitivity.
(iv) Analytical specificity to include interfering substances.
(v) Reportable range of test results for the test system.
(vi) Reference intervals (normal values).
(vii) Any other performance characteristic required for test performance.
(3) Determination of calibration and control procedures. The laboratory must determine the test system's calibration procedures and control procedures based upon the performance specifications verified or established under paragraph (b)(1) or (b)(2) of this section.

I hope you find this feedback useful.  I’ve prepared a document that outlines how a laboratory can comply with the standards and would be happy to share it with you; simply send me a message and I will respond accordingly.
Best Wishes,
Joe Myers, M.S., CT/QIHC(ASCP)

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Message: 2
Date: Tue, 2 Jun 2020 09:25:03 -0700
From: "Paula" <plucas at biopath.org>
To: <histonet at lists.utsouthwestern.edu>
Subject: [Histonet] IHC validations

Hello,
I see 10 positive and 10 negative cases for CAP guidelines, but what about for CLIA?  What is their guideline to validate an IHC antibody?

Thanks in advance,
Paula