Clinical Application of 20 MHz Endosonography and Anti‐Helicobacter pylori Immunoblots to Predict Regression of Low‐grade Gastric MALToma by H. pylori Eradication

Abstract

Aim. We tested whether serial 20 MHz endosonography (EUS) and anti‐Helicobacter pylori immunoblots can predict the complete regression of gastric MALToma by H. pylori eradication. Methods. The serums of 17 MALToma patients, including 15 with low grade and two with high grade, were collected before therapy. Fifteen patients with low‐grade MALToma and 18 nonMALToma patients, all infected with H. pylori, have been followed with serum sampling, endoscopy, and EUS on enrollment, on the 2nd, 6th, and 12th months after anti‐H. pylori therapy. All sera were tested for anti‐H. pylori immunoblots, including 19.5, 26.5, 30, 35, 89, 116 KDa (CagA), FldA. The DNAs were extracted serially from the biopsy of MALToma patients before and after therapy to perform polymerase chain reaction (PCR) for the immunoglobulin heavy‐chain gene monoclonality. Results. MALToma patients had higher prevalence rates of anti‐FldA protein, 19.5 and 30 KDa antibodies of H. pylori (p < 0.01). After H. pylori eradication, MALToma patients had negative seroconversion of 19.5, 26.5, 30, and 35 KDa antibodies (p < 0.05), but not in CagA and FldA. The PCR monoclonality occurred in 80% (12/15) of the MALToma patients before therapy, but did not correlate with any seroconversion of anti‐H. pylori immunoblots after therapy (p > 0.05). Complete regression of MALToma was observed in 73.3% (11/15) of patients. Evaluation with 20 MHz EUS, for the initial tumor depth and its normalization on the 6th month had 90.9% sensitivity and 100% specificity to predict the complete regression. Discussion. The negative seroconversions of the smaller‐molecular‐weight proteins, but not CagA and FldA, correlate with regression of MALToma by H. pylori eradication. 20 MHz EUS can effectively predict the therapeutic response of MALToma.

Serological Responses of FldA and Small‐Molecular‐Weight Proteins of Helicobacter pylori: Correlation with the Presence of the Gastric MALT Tissue

“…The contradictory concept was further supported by our recent study, which showed that the negative seroconversion of anti‐ H. pylori immunoblots of FldA and CagA was not consistently followed by the complete regression of MALToma [8]. In our previous study, the serological responses to the small‐molecular‐weight proteins (SMWP) of H. pylori could be consistently converted as negative results after the tumor regression [8]. It is thus imperative to determine whether the SMWP of H. pylori could be related to the formation of MALT in gastric tissue.…”

“…However, whether the FldA and CagA could be significant virulent bacterial factors involved in the pathogenesis of MALT lymphoma remains a matter of debate, as contradictory data were also observed [12,13]. The contradictory concept was further supported by our recent study, which showed that the negative seroconversion of anti‐ H. pylori immunoblots of FldA and CagA was not consistently followed by the complete regression of MALToma [8]. In our previous study, the serological responses to the small‐molecular‐weight proteins (SMWP) of H. pylori could be consistently converted as negative results after the tumor regression [8].…”

“…Despite the regression of grade 4 or 5 (MALToma) to a lower grade ranging from 0 to 3, the serological response of anti‐CagA and anti‐FldA of patients with MALToma after anti‐ H. pylori therapy was persistently present [8]. This finding also makes it necessary to test whether FldA or CagA are relevant to the existence or severity in the grading of MALT.…”

Helicobacter pylori colonization of the human gastric epithelium: A bug's first step is a novel target for us

“…The diverse outcomes after H. pylori infection are attributable to the H. pylori virulence factors, host genomic predisposition, and other environmental factors 7–9 . Nevertheless, successful H. pylori colonization is the leading step that links the host to risks of developing gastritis, peptic ulcer, gastric adenocarcinoma or MALToma 10–12 . As such, understanding the pathways of H. pylori colonization is important for selecting novel targets to prevent the development of H. pylori ‐related diseases.…”

Staging role of EUS

“…H. pylori eradication is the initial treatment of choice in all gastric MALT The predictive value of EUS with respect to response to H. pylori eradication or radio-/chemotherapy is another challenge. In several studies using radial EUS or miniechoendoscopes a high predictive value has been shown [20][21][22][23][24][25][26] (Table 3). In all studies, a stage EI1 lymphoma was associated with a higher remission rate (up to 100%) as compared to lymphoma of stages EI2 and EII1.…”