Potential for improving therapy and defining new research targets in eosinophilic oesophagitis based on understanding of immunopathogenesis

Lymphocytic oesophagitis, eosinophilic oesophagitis and compound lymphocytic-eosinophilic oesophagitis I: histological and immunohistochemical findings

AIMS

To report four histological-immunohistochemical oesophagitis phenotypes.

METHODS

Oesophageal biopsies from 311 patients were stained with H&E and with CD3, a T cell marker. Additional immunohistochemical stains (n=413) were performed in 77 cases.

RESULTS

Four histological-immunohistochemical oesophagitis phenotypes were recorded: lymphocytic oesophagitis (LyE, ≥40 CD3+ lymphocytes/HPF in CD3 immunostain), eosinophilic oesophagitis (EoE, ≥15 eosinophils/HPF in H&E stain), lymphocytic infiltration (≤39 CD3+/HPF) and compound lymphocytic oesophagitis-eosinophilic oesophagitis (Co LyE-EoE). At index biopsy, 28.3% (n=88) had LyE, 21.2% (n=66) EoE, 10.6% (n=33) Co LyE-EoE and 39.9% (n=124) lymphocytic infiltration. A persistent oesophagitis phenotype was found in 42.5% (37/87) in the first follow-up biopsy, in 34.4% (21/61) in the second follow-up biopsy and in 48.1% (26/54) in the third follow-up biopsy. Using βF1 immunostain, two different surface T cell receptors were detected in LyE and Co Lye-EoE: one having ≥40 βF1+/HPF (βF1+ high) and the other having <39 βF1+/HPF (βF1+ low).

CONCLUSIONS

Based on the literature regarding the significance of intraepithelial lymphocytes (IELs) in the initiation of EoE, we submit that the IEL phenotypes in LyE might differ from those found in EoE as they were unable to elicit the same eosinophilic response. Recent studies disclosed that group 2 innate lymphocytes (ILC2s), enriched in EoE, remain undetected in CD3 immunostain as they lack surface markers for T, B, natural killer (NK) or NK T cells. If ILC2s also participate in the lymphocytic infiltration of EoE, then the frequency of cases with Co LyE-EoE here reported might have been much higher. The four oesophagitis phenotypes described are easy to recognise, provided that the dual staining procedure (H&E-CD3) is implemented.

Morphological and Functional Assessment of Oesophageal Mucosa Integrity in Children With Cystic Fibrosis

OBJECTIVES

The aim of the study was to investigate morphological and functional characteristics of oesophageal epithelial barrier in children with cystic fibrosis (CF) with or without gastro-oesophageal reflux disease (GORD) in comparison to healthy controls.

METHODS

Oesophagogastroduodenoscopy with oesophageal biopsies and combined oesophageal multichannel intraluminal impedance-pH monitoring was performed in 17 children with CF (CFtot) with (CFgord) or without GORD (CFnorm). Histological combined severity score was calculated and widths of spaces between epithelial cells were measured. Basal impedance value was used to assess functional integrity of epithelial barrier. Results of each investigation were compared with a group of children without oesophageal disease.

RESULTS

CFtot, but also CFnorm, had more severe pathohistological changes included in the compound severity score than controls (0.75 ± 0.32 and 0.75 ± 0.20 vs 0.27 ± 0.25; P < 0.001 and P = 0.001, respectively). They also had more dilated intercellular spaces (2.6 μm ± 0.6 and 2.7 μm ± 0.5 vs 1.9 μm ± 0.2; P = 0.001 and P < 0.001, respectively). Baseline impedance values between proximal and distal pairs of electrodes were significantly lower in CFtot (2876 Ω ± 484, 2590 Ω ± 1013) and also in CFnorm (2922 Ω ± 363, 2844 Ω ± 457) than in controls (3703 Ω ± 859, 3753 Ω ± 1070) (P = 0.012 and P = 0.002; and P = 0.027 and P = 0.005, respectively). The treatment of CFgord with proton pump inhibitor increased, but did not normalise the baseline impedance values (2860 Ω ± 560 to 3355 Ω ± 750 and 2178 Ω ± 1564 to 3057 Ω ± 594).

CONCLUSIONS

Children with CF had morphological and functional changes of oesophageal mucosal integrity even in the absence of GORD.