Table 2 Definition of different total serum IgE levels cutoffs
IgE deficiency Ultra-low/absent total serum IgE levels (kU/L) IgE < 2.5 | Normal total serum IgE levels (kU/L) 2.5 ≥ IgE < 100 | High total serum IgE levels (kU/L) 100 ≥ IgE < 1,000 | Very high total serum IgE levels (kU/L) 1,000 ≥ IgE < 10,000 | Extremely high total serum IgE levels (kU/L) IgE ≥ 10,000 |
|---|---|---|---|---|
Very low or absent IgE levels may be found in patients with allergic rhinitis-, chronic sinusitis-like symptoms and asthma [32, 36, 37, 58] | Cannot exclude atopic/allergic or parasitic conditions | Biomarker for atopy/allergy [29, 44, 45, 53, 55], parasitosis [71,72,73] | ||
Might potentially be used as a marker for higher cancer susceptibility [32,33,34] | Some patients with normal IgE levels may have higher rates of malignancy [18, 20] | In general, elevated IgE levels are associated with lower rates and risk for malignancy [17, 20, 21, 142]. Very high and extremely high total serum IgE levels are seen in certain malignancies such as lymphoma [146] and IgE myeloma [147] | ||
May be a sensitive and specific marker for CVID (Common Variable Immunodeficiency) when there is high suspicion for primary humoral deficiency [38] | Cannot exclude immunodeficiency | Elevated IgE levels may raise suspicion for certain immunodeficiencies in appropriate patients (e.g. HyperIgE syndrome (HIES), Wiskott-Aldrich syndrome; immunodysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX); Omenn syndrome; Atypical complete DiGeorge syndrome) [35, 83, 86] | ||