21 CFR § 866.5110 - Antiparietal antibody immunological test system.

---
identifier: "/us/cfr/t21/s866.5110"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "21 CFR § 866.5110 - Antiparietal antibody immunological test system."
title_number: 21
title_name: "Food and Drugs"
section_number: "866.5110"
section_name: "Antiparietal antibody immunological test system."
chapter_name: "FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES"
subchapter_number: "H"
subchapter_name: "MEDICAL DEVICES"
part_number: "866"
part_name: "IMMUNOLOGY AND MICROBIOLOGY DEVICES"
positive_law: false
currency: "2026-04-05"
last_updated: "2026-04-05"
format_version: "1.1.0"
generator: "[email protected]"
authority: "21 U.S.C. 351, 360, 360c, 360e, 360j, 360 371."
regulatory_source: "47 FR 50823, Nov. 9, 1982, unless otherwise noted."
cfr_part: "866"
---


# 866.5110 Antiparietal antibody immunological test system.

(a) *Identification.* An antiparietal antibody immunological test system is a device that consists of the reagents used to measure by immunochemical techniques the specific antibody for gastric parietal cells in serum and other body fluids. Gastric parietal cells are those cells located in the stomach that produce a protein that enables vitamin B<sub>12</sub> to be absorbed by the body. The measurements aid in the diagnosis of vitamin B<sub>12</sub> deficiency (or pernicious anemia), atrophic gastritis (inflammation of the stomach), and autoimmune connective tissue diseases (diseases resulting when the body produces antibodies against its own tissues).

(b) *Classification.* Class II (performance standards).