Helicobacter pylori infection in patients with selective immunoglobulin E deficiency

Impaired Response to Polysaccharide Vaccine in Selective IgE Deficiency

PURPOSE

Immunoglobulin E deficiency (IgED) (defined as IgE < 2 IU/mL) is enriched in patients with primary antibody deficiency (PAD). We hypothesized that selective IgED (sIgED) is a more sensitive predictor of the development of PAD than declining IgG, as IgE production typically requires two class switch recombination (CSR) events in contrast to IgG. Thus, the inability of patients with sIgED to mount an appropriate antibody response to a T-cell independent antigen or evidence of aberrant induction of ɛ germ line (ɛGL) or IgE heavy chain (IgEHC) transcripts in vitro would support the concept that sIgED is a biomarker for emerging PAD.

METHODS

We compared pre- and post-polysaccharide vaccination titers in healthy patients with sIgED without a history of recurrent infections or autoimmunity (n = 20) and in healthy controls (HCs) (n = 17). Subsequently, we assessed in vitro induction of εGL and IgEHC transcripts in patients with sIgED and HC (n = 6) in response to IL-4 + CD40L stimulation.

RESULTS

Thirty percent of patients with sIgED did not have a robust vaccine response compared to 0% of HCs (p = 0.017). Individuals with sIgED with an abnormal vaccine response demonstrated persistent germline mRNA expression in their B-cells at day 5, with lower levels of IgEHC, compared to both HCs and sIgED participants with a normal vaccine response.

CONCLUSION

Patients with sIgED are more likely to have abnormal antibody responses to a T cell-independent antigen and may have dysregulated CSR machinery. Following individuals with sIgED longitudinally may be beneficial in the early identification of PAD.

Factors associated with IgG levels in adults with IgG subclass deficiency

Background

Factors associated with IgG levels in adults with IgG subclass deficiency (IgGSD) are incompletely understood. We studied adults with IgGSD with subnormal IgG1 only, subnormal IgG1/IgG3, or subnormal IgG3 only without other subnormal IgG subclasses, IgA, or IgM. We compiled: age; sex; autoimmune condition(s) (AC); atopy; IgG, IgG subclasses, IgA, IgM; IgGsum (IgG1 + IgG2 + IgG3 + IgG4); and D (percentage difference between IgGsum and IgG). We compared attributes of patients with/without subnormal IgG (< 7.00 g/L; subnormal IgG1 subclass groups only) and analyzed IgGsum and IgG relationships. We performed backward stepwise regressions on IgG using independent variables IgG subclasses, age, and sex and on D using independent variables age and sex.

Results

There were 39 patients with subnormal IgG1 only (89.7% women), 53 with subnormal IgG1/IgG3 (88.7% women), and 115 with subnormal IgG3 only (91.3% women). Fifteen patients (38.5%) and 32 patients (60.4%) in the respective subnormal IgG1 subclass groups had subnormal IgG. Attributes of patients with/without IgG < 7.00 g/L were similar, except that AC prevalence was lower in patients with subnormal IgG1 only and IgG < 7.00 g/L than ≥ 7.00 g/L (p = 0.0484). Mean/median IgG1 and IgG2 were significantly lower in patients with IgG < 7.00 g/L in both subnormal IgG1 subclass groups (p < 0.0001, all comparisons). Regressions on IgG in three subclass groups revealed positive associations with IgG1 and IgG2 (p < 0.0001 each association). Regressions on D revealed no significant association. IgG1 percentages of IgGsum were lower and IgG2 percentages were higher in patients with subnormal IgG1 subclass levels than subnormal IgG3 only (p < 0.0001 all comparisons).

Conclusions

We conclude that both IgG1 and IgG2 are major determinants of IgG in patients with subnormal IgG1, combined subnormal IgG1/IgG3, or subnormal IgG3 and that in patients with subnormal IgG1 or combined subnormal IgG1/IgG3, median IgG2 levels are significantly lower in those with IgG < 7.00 g/L than those with IgG ≥ 7.00 g/L.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12865-021-00447-3.

Low Serum IgE Is a Sensitive and Specific Marker for Common Variable Immunodeficiency (CVID)

Although small prior studies have suggested that IgE can be low in common variable immunodeficiency (CVID), the workup for patients with recurrent infections and suspected hypogammaglobulinemia does not include the routine measurement of serum IgE. We sought to test the hypothesis that low/undetectable serum IgE is characteristic of CVID by comparing the frequency of low/undetectable serum IgE in healthy controls and patients with CVID. We measured total serum IgE in a large multi-center cohort of patients with CVID (n = 354) and compared this to large population-based cohorts of children and adults. We further compared IgE levels in patients with CVID to those with other forms of humoral immunodeficiency, and in a subset, measured levels of allergen-specific serum IgE and IgG subclasses. Lastly, we evaluated for the presence of IgE in commercially available immunoglobulin replacement therapy (IgRT) products. An undetectable serum IgE (< 2 IU/ml) occurs in only 3.3% (95% CI, 1.9-5.7%) of the general population. In contrast, an undetectable IgE occurs in 75.6% (95% CI, 65.6-85.7%) of patients with CVID. Conversely, a high IgE (> 180 IU/ml) is very uncommon in CVID (0.3% of patients). IgE is > 2 IU/ml in 91.2% of patients with secondary hypogammaglobulinemia, and thus, an IgE < LLOD is suggestive of a primary humoral immunodeficiency. Allergen-specific IgE is not detectable in 96.5% of patients with CVID. Sufficient quantities of IgE to change the total serum IgE are not contained in IgRT. The IgG1/IgG4 ratio is increased in subjects with low IgE, regardless of whether they are controls or have CVID. These findings support the routine measurement of serum IgE in the workup of patients with hypogammaglobulinemia.

Helicobacter pylori infection in patients with selective immunoglobulin a deficiency

Selective immunoglobulin A (IgA) deficiency (IgAD) is the most common primary immunodeficiency in the western world. The aim of the study was to investigate the prevalence and clinical characteristics of Helicobacter pylori-infected dyspeptic patients with IgAD. Case samples were drawn from all subjects ≥ 12 years of age (n = 104729) who had undergone serum total IgA measurements during 2004-14 for any reason at Leumit Healthcare Services (Israel) and had serum total IgA < 0·07 g/l. The control group was comprised of a random sample of remaining patients with a case-control ratio of 10 controls for each case. The dyspeptic diseases were identified and retrieved from Leumit Health Care Services electronic database using specific ICD-9-CM diagnostic codes. The case group included 347 subjects and the control group 3470 subjects. There were no significant differences in the prevalence of patients with dyspepsia [84 (24·2%) versus 821 (23·6%) for cases and controls, respectively]. Additionally, there was no difference in a proportion of dyspeptic H. pylori-positive subjects [59 (17·1%) versus 524 (15·1%)] between the case and control groups. Only 59 (17%) among the 347 IgAD patients underwent gastroscopy. A significantly larger proportion of case subjects experienced several forms of gastritis [13 (61·9%) versus 38 (21·6%), P < 0·001), duodenal ulcers [seven (33·3%) versus 19 (10·8%); P = 0·01] and nodular lymphoid hyperplasia (NLH) [two (9·5%) versus none; P = 0·011]. IgAD is not associated with increased prevalence of H. pylori-associated dyspepsia; nevertheless, H. pylori-infected dyspeptic IgAD subjects experience more EGD-proved gastritis, duodenal ulcers and NLH.