Is There a Clinical Significance of Very Low Serum Immunoglobulin E Level?

The Association Between Malignancy, Immunodeficiency, and Atopy in IgE-Deficient Patients

BACKGROUND

Studies show that IgE-deficient patients (IgE <2.5 kU/L) have a high prevalence of malignancy, but relevant clinical and laboratory characteristics associated with this susceptibility have never been well characterized.

OBJECTIVE

To evaluate if there is an association between a malignancy diagnosis and other immunological parameters (atopy or other immune abnormalities) in IgE-deficient patients.

METHODS

We retrospectively analyzed medical records of 408 IgE-deficient adults seen at our institution between 2005 and 2020.

RESULTS

A malignancy diagnosis was found in 23.5% (96 of 408) of IgE-deficient patients. Among those who had allergy skin testing performed for allergic rhinitis-like symptoms, the nonatopic IgE-deficient patients (negative environmental skin tests) were more likely to have a malignancy diagnosis than the atopic group (odds ratio [OR] = 4.36, 95% confidence interval [CI]: 1.11-17.13, P = .03). The IgE-deficient individuals with an additional non-common variable immunodeficiency (non-CVID) humoral abnormality (n = 75; with low IgG, IgA, or IgM without meeting criteria for CVID) were more likely to have a malignancy diagnosis than those with only a selective IgE deficiency (n = 134; with normal IgA, IgM, and IgG) (OR = 2.79, 95% CI: 1.37-5.68, P = .005). Among the IgE-deficient patients, certain less well-defined immune abnormalities such as IgM deficiency (OR = 2.46, 95% CI: 1.13-5.36, P = .02), IgG2 deficiency (OR = 10.14, 95% CI: 1.9-54.1, P = .007), and CD4 lymphopenia (OR = 7.81, 95% CI: 2.21-27.63, P = .001) were associated with higher malignancy odds than those without these abnormalities.

CONCLUSION

The odds of a malignancy diagnosis are not shared equally by all IgE-deficient patients. Prospective studies are needed to determine the utility of performing skin testing and measuring additional immunological parameters in assessing the long-term malignancy risk in IgE-deficient patients.

Autoimmune Diseases and Low Baseline IgE in Chronic Spontaneous Urticaria: A Clinical and Therapeutic Prospective Analysis in Real-Life Clinical Practice

BACKGROUND

Autoimmunity contributes to the pathogenesis of chronic spontaneous urticaria (CSU). The subtyping of CSU has revealed an autoimmune form of CSU. Despite autoimmune diseases having been associated with CSU, there are few prospective studies that have evaluated the characteristics and biomarkers of patients with CSU and autoimmune disease in a real-life practice setting.

OBJECTIVE

To evaluate the presence of specific biomarkers for the presence of autoimmune disease in CSU and to analyze the clinical and therapeutic features of patients with CSU and autoimmune disease.

METHODS

The clinical, laboratory, and therapeutic features of patients with CSU at a tertiary-level center were prospectively collected. Data obtained were compared in function of the presence/absence of autoimmune disease and typified according to IgE levels.

RESULTS

Patients with CSU who had associated autoimmune disease corresponded to middle-aged women with a common pattern of blood test findings: both low baseline IgE and high-affinity receptor of IgE expression, basopenia, eosinopenia, higher baseline erythrocyte sedimentation rate and D-dimer, increased presence of antinuclear antibodies, IgG against thyroid peroxidase, and positive autologous serum skin test result. Total baseline IgE less than or equal to 43.8 IU/mL was both the optimal cutoff to predict autoimmune disease in the CSU cohort and a significant risk factor for the presence of autoimmune disease in the regression analysis.

CONCLUSIONS

In real-life clinical practice, characteristics of patients with CSU and autoimmune disease share common features with type IIb autoimmune CSU. Total baseline IgE less than or equal to 43.8 IU/mL has been detected as a possible biomarker of autoimmune disease in patients with CSU.

A survey of total IgE reference intervals reported by Scandinavian and British medical laboratories - a need for harmonisation

OBJECTIVES

There appears to be marked discrepancies between total IgE reference intervals (RIs) in use by many laboratories and those recommended by published studies. The aim of this study was therefore to review total IgE RIs currently reported by Scandinavian and British laboratories and to compare these to published RIs identified by a literature review.

METHODS

Relevant laboratories were identified by test directories provided by the national accreditation bodies in Norway, Sweden, Denmark and the UK. Total IgE RIs and their sources were acquired by accessing laboratory user handbooks or by an electronic survey. In addition a literature review of published total IgE RI studies was performed.

RESULTS

From 172 accredited laboratories providing total IgE analysis, data was acquired from 122 laboratories. An adult upper reference limit between 81 to 150 kU/L was reported by 89% of these. Denmark and Sweden reported the most harmonised RIs whilst Norway and the UK exhibited the least degree of harmonisation. Published adult (n = 6) and paediatric (n = 6) RI studies reported markedly higher upper limits than those currently in use by the laboratories included in this study. There were also large variations in the number of age strata in use for paediatric RIs.

CONCLUSION

This study demonstrates large variations in currently utilised IgE RIs by Scandinavian and British accredited laboratories and most report markedly lower RIs than those recommended by recent RI publications. Many laboratories likely utilise outdated RIs and should consider critically reviewing and updating their RIs.

Updated total IgE reference intervals in Norwegian adults

BACKGROUND

It is important and expected of laboratories to provide updated reference intervals to the clinician. As no recent publications report adult total IgE reference intervals on a Scandinavian population, the aim of our study was therefore to provide an estimate on healthy Norweigian adults.

METHODS

A reference interval study was conducted in accordance to CLSI guidelines. Samples were collected from n = 252 presumably healthy adult participants enrolled through the regional blood donation program. Total IgE measurements were performed on the ImmunoCAP^TM platform (Thermo Fisher Diagnostics) traceable to the WHO-reference standard (75/502) for total IgE measurements.

RESULTS

An upper 95% total IgE reference limit was estimated to 302 kU/L (90% CI 177-388 kU/L), and the 97.5% percentile was estimated to 391 kU/L (90% CI 344-560 kU/L). No significant differences were found between participants who self-reported having an allergic disease and participants who did not self-report having an allergic disease.

CONCLUSION

Our results and other recent publications find markedly higher values than adult reference intervals established four decades ago which still remain widely used by clinical laboratories. We therefore recommend total IgE reference intervals should be critically reviewed and updated.