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Zinc Transporter 8 (ZnT8) Antibody
Test CodeZNT8
Quest Code
93022
CPT Codes
86341
Preferred Specimen
1 mL serum
Minimum Volume
0.5 mL
Transport Temperature
Room temperature
Specimen Stability
Room temperature: 7 days
Refrigerated: 7 days
Frozen: 28 days
Refrigerated: 7 days
Frozen: 28 days
Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Gross hemolysis • Lipemia • Icterus • Specimens other than serum
Methodology
Enzyme Linked Immunosorbent Immunoassay (ELISA)
Setup Schedule
Set up: Wed, Sat; Report available: 5-6 days
Reference Range
<15 U/mL
Clinical Significance
Key clinical use and differentiators
Measurement of Zinc transporter type 8 (ZnT8) is used to: 1. Screen for presymptomatic T1D in individuals with a family history of type 1 diabetes (T1D) or those known to have a high-risk HLA genotype, 2. Distinguish between T1D, type 2 diabetes mellitus (T2D), and atypical forms of diabetes such as latent autoimmune diabetes in adults (LADA).
Zinc transporter type 8 (ZnT8) is a transmembrane protein in the beta cell granule which is attacked by the ZnT8 antibody in patients with T1D.
Intended Clinical Use
This test is crucial for differentiating between T1D and T2D. It is important to note that classifying diabetes type can be challenging at the time of presentation, and misdiagnosis can occur in approximately 40% of adults with new T1D. [1]
Identifying individuals affected by stage 1 T1D is important for applying eligibility criteria to drugs, such as Teplizumab, which have demonstrated the ability to delay the transition of stage 1 to stage 3 T1D in clinical trials. [2,3]
ZnT8 has some distinctive features, including that its presence can improve risk stratification in individuals with single GADA+, IAA+ or IA-2A+ status. In one study, half of the children who developed ZnT8 developed diabetes within 5 years.[4]
Limitations
T1D is classified into three stages, with stages 1 and 2 considered presymptomatic. Since the presence of stage 1 and 2 T1D requires at least two islet autoantibodies, relying solely on ZnT8 as a screening test limits the ability to make an accurate diagnosis. Professional organizations, including the American Diabetes Association (ADA), recommend using tests for all four islet cell autoantibodies: IAA, glutamic acid decarboxylase (GAD65), Zinc Transporter 8 (ZnT8), and islet cell antigen 2 antibody (IA-2).[1]
References
1. American Diabetes Association Professional Practice C. 2. Diagnosis and Classification of Diabetes: Standards of care in Diabetes-2025. Diabetes Care. 2025;48:S27-S49. doi: 10.2337/dc25-S002
2. Herold KC, Gitelman SE, Gottlieb PA, Knecht LA, Raymond R, Ramos EL. Teplizumab: A Disease-Modifying Therapy for Type 1 Diabetes That Preserves beta-Cell Function. Diabetes Care. 2023;46:1848-1856. doi: 10.2337/dc23-0675
3. Ramos EL, Dayan CM, Chatenoud L, Sumnik Z, Simmons KM, Szypowska A, Gitelman SE, Knecht LA, Niemoeller E, Tian W, et al. Teplizumab and beta-Cell Function in Newly Diagnosed Type 1 Diabetes. N Engl J Med. 2023;389:2151-2161. doi: 10.1056/NEJMoa2308743
4. Achenbach P, Lampasona V, Landherr U, Koczwara K, Krause S, Grallert H, Winkler C, Pfluger M, Illig T, Bonifacio E, et al. Autoantibodies to zinc transporter 8 and SLC30A8 genotype stratify type 1 diabetes risk. Diabetologia. 2009;52:1881-1888. doi: 10.1007/s00125-009-1438-0
Measurement of Zinc transporter type 8 (ZnT8) is used to: 1. Screen for presymptomatic T1D in individuals with a family history of type 1 diabetes (T1D) or those known to have a high-risk HLA genotype, 2. Distinguish between T1D, type 2 diabetes mellitus (T2D), and atypical forms of diabetes such as latent autoimmune diabetes in adults (LADA).
Zinc transporter type 8 (ZnT8) is a transmembrane protein in the beta cell granule which is attacked by the ZnT8 antibody in patients with T1D.
Intended Clinical Use
This test is crucial for differentiating between T1D and T2D. It is important to note that classifying diabetes type can be challenging at the time of presentation, and misdiagnosis can occur in approximately 40% of adults with new T1D. [1]
Identifying individuals affected by stage 1 T1D is important for applying eligibility criteria to drugs, such as Teplizumab, which have demonstrated the ability to delay the transition of stage 1 to stage 3 T1D in clinical trials. [2,3]
ZnT8 has some distinctive features, including that its presence can improve risk stratification in individuals with single GADA+, IAA+ or IA-2A+ status. In one study, half of the children who developed ZnT8 developed diabetes within 5 years.[4]
Limitations
T1D is classified into three stages, with stages 1 and 2 considered presymptomatic. Since the presence of stage 1 and 2 T1D requires at least two islet autoantibodies, relying solely on ZnT8 as a screening test limits the ability to make an accurate diagnosis. Professional organizations, including the American Diabetes Association (ADA), recommend using tests for all four islet cell autoantibodies: IAA, glutamic acid decarboxylase (GAD65), Zinc Transporter 8 (ZnT8), and islet cell antigen 2 antibody (IA-2).[1]
References
1. American Diabetes Association Professional Practice C. 2. Diagnosis and Classification of Diabetes: Standards of care in Diabetes-2025. Diabetes Care. 2025;48:S27-S49. doi: 10.2337/dc25-S002
2. Herold KC, Gitelman SE, Gottlieb PA, Knecht LA, Raymond R, Ramos EL. Teplizumab: A Disease-Modifying Therapy for Type 1 Diabetes That Preserves beta-Cell Function. Diabetes Care. 2023;46:1848-1856. doi: 10.2337/dc23-0675
3. Ramos EL, Dayan CM, Chatenoud L, Sumnik Z, Simmons KM, Szypowska A, Gitelman SE, Knecht LA, Niemoeller E, Tian W, et al. Teplizumab and beta-Cell Function in Newly Diagnosed Type 1 Diabetes. N Engl J Med. 2023;389:2151-2161. doi: 10.1056/NEJMoa2308743
4. Achenbach P, Lampasona V, Landherr U, Koczwara K, Krause S, Grallert H, Winkler C, Pfluger M, Illig T, Bonifacio E, et al. Autoantibodies to zinc transporter 8 and SLC30A8 genotype stratify type 1 diabetes risk. Diabetologia. 2009;52:1881-1888. doi: 10.1007/s00125-009-1438-0
Performing Laboratory
Quest Diagnostics Nichols Institute
33608 Ortega Highway
San Juan Capistrano, CA 92675-2042
