Total IgA optimal range and reference range

Compiled by Alina Radu, founder of Sera, from the published sources below · Last reviewed November 9, 2026

Sera's bands for Total IgA:

Optimal 70 – 356 mg/dL (0.7 – 3.56 g/L); sufficient 61 – 356 mg/dL (0.61 – 3.56 g/L); out of range below 61 or above 356 mg/dL.

Evidence grade: Published reference interval. A band that primarily reflects a published adult laboratory or population reference interval. It is not necessarily applicable to every assay or laboratory.

All units

Unit	Optimal	Sufficient	Out of range
mg/dL	70 – 356	61 – 356	below 61 or above 356
g/L	0.7 – 3.56	0.61 – 3.56	below 0.61 or above 3.56

What the evidence says

Measured to qualify the coeliac panel rather than for its own sake. Selective IgA deficiency affects roughly 1 in 500 people and is several times more common in coeliac disease, so the low edge is the one that matters here. The band is the Mayo Clinic Laboratories adult reference interval, 61 to 356 mg/dL (0.61 to 3.56 g/L); other laboratories set their lower limit anywhere from 61 to 90 mg/dL, so the interval on the report takes precedence. Selective IgA deficiency is defined much lower, as below 7 mg/dL (0.07 g/L) with normal IgG and IgM. A result between 7 mg/dL and the lower limit is a partial deficiency: it still weakens a negative tTG IgA. The narrower optimal band is a functional target; no published evidence supports it.

Sources

Immunoglobulin A (IgA), Serum — Mayo Clinic Laboratories, 2026 · Laboratory / reference-interval sourceAdult reference interval, 18 years and over: 61 to 356 mg/dL. This is the proposed sufficient band (0.61 to 3.56 g/L).
Immunoglobulin A, Quantitative — Labcorp, 2026 · Laboratory / reference-interval sourceAdult intervals by sex and age: men 16 to 60 years 90 to 386 mg/dL, men over 60 61 to 437; women 16 to 70 years 87 to 352, women over 70 64 to 422. Shows that lower limits run from 61 to 90 and that no adult row reaches down to 50 or up to 450.
Selective IgA Deficiency and Allergy: A Fresh Look to an Old Story — Cinicola BL, Pulvirenti F, Capponi M, et al. — Medicina (Kaunas), 2022 · Peer-reviewed publicationItalian review giving the standard definition of selective IgA deficiency: IgA below 7 mg/dL with normal IgG and IgM in someone older than 4 years. This is far below the reference interval's lower limit and is the level at which IgA-based coeliac serology cannot be relied on.
American College of Gastroenterology Guidelines Update: Diagnosis and Management of Celiac Disease — Rubio-Tapia A, Hill ID, Semrad C, et al. — American Journal of Gastroenterology (American College of Gastroenterology), 2023 · Clinical guidelineEstablishes tTG IgA as the first-line serologic test, requires total IgA to be measured alongside it because selective IgA deficiency invalidates a negative result, and requires the patient to be eating gluten. It does not set a numeric cut-off — that belongs to the assay.

What Total IgA (Immunoglobulin A) measures

The total amount of immunoglobulin A in the blood, measured to check whether IgA-based coeliac tests can be trusted.

Selective IgA deficiency affects roughly 1 in 500 people and is several times more common in coeliac disease. Without this, a negative tTG IgA cannot be distinguished from a person who cannot make the antibody at all.

Related autoimmune markers

See Total IgA in the full list of biomarker ranges

This page is a reference for practitioners, not medical advice. Sera's bands are practitioner targets for structured review, not diagnostic thresholds, and Sera does not diagnose or recommend treatment. Read a result alongside the interval printed by the issuing laboratory and the client's history and symptoms. Range set: Sera Production, version 1.0, last reviewed November 9, 2026.