Comment on Skrebinska et al. Who Could Be Blamed in the Case of Discrepant Histology and Serology Results for Helicobacter pylori Detection? Diagnostics 2022, 12, 133

In their article, Skebrinska and colleagues analysed the potential pitfalls of detecting Helicobacter pylori (H. pylori) by serology, histological (Giemsa) and immunohistochemical (IHC) staining. However, in the Introduction, the authors state: " horizontal ellipsis IHC is recommended only in individuals with active gastritis without H. pylori identification by histochemistry". Although this is a widely-held view, it does not seem to hold up in view of the results of the study by Kocsmar et al., which showed that the diagnostic sensitivity of Giemsa in the absence of activity is only 33.6%, but it is 92.6% in the presence of active gastritis, which is close to the 99.4% sensitivity of IHC. Considering that chronic active gastritis with the features of H. pylori gastritis is also common in other entities, if active inflammation is present in the sample, there is a very small chance that a Giemsa-negative case will be confirmed as H. pylori-positive by IHC. Based on this, the use of IHC is more reasonable in Giemsa-negative cases with no activity in which the etiological role of H. pylori is suggested by clinical, anamnestic or other data. However, it may also be reasonable to routinely use IHC as the primary staining method instead of Giemsa.