Lanthanum-Induced Mucosal Alterations in the Stomach (Lanthanum Gastropathy): a Comparative Study Using an Animal Model

Novel case of laparoscopically resected gastric adenocarcinoma concurrent with lanthanum deposition

A 73-year-old man taking lanthanum carbonate for hemodialysis showed progressing gastric mucosal changes with lanthanum deposition. Regular examination revealed concurrent gastric carcinoma. The extent and depth of its invasion were ambiguous because of the surrounding lanthanum deposition. Furthermore, there could be other potent carcinomas, and curative laparoscopic gastrectomy was performed.

Gastric lanthanosis (lanthanum deposition) in an immunosuppressed patient that discontinued lanthanum carbonate seven years ago

A 72-year-old female patient used the oral phosphate binder lanthanum carbonate for 6 years, before discontinuing it after receiving a pancreas and kidney transplant. Now, 7 years after discontinuation, the patient developed bilious emesis. An upper gastrointestinal endoscopy showed an unspecific gastritis. Biopsies showed subepithelial crystalline deposits consistent with gastric lanthanosis.

Histopathological classification and follow-up analysis of chronic atrophic gastritis

BACKGROUND

The pathological diagnosis and follow-up analysis of gastric mucosal biopsy have been paid much attention, and some scholars have proposed the pathological diagnosis of 12 kinds of lesions and accompanying pathological diagnosis, which is of great significance for the treatment of precision gastric diseases, the improvement of the early diagnosis rate of gastric cancer, and the reduction of missed diagnosis rate and misdiagnosis rate.

AIM

To perform a histopathological classification and follow-up analysis of chronic atrophic gastritis (CAG).

METHODS

A total of 2248 CAG tissue samples were collected, and data of their clinical characteristics were also gathered. Based on these samples, the expression levels of Mucin 1 (MUC1), MUC2, MUC5AC, and MUC6 in CAG tissue were tested by immunohistochemical assay. Moreover, we followed these patients for up to four years. The difference between different stages of gastroscopic biopsy was observed.

RESULTS

Through observation, it is believed that CAG should be divided into four types, simple type, hyperplasia type, intestinal metaplasia (IM) type, and intraepithelial neoplasia (IEN) type. Simple CAG accounted for 9.1% (205/2248), which was more common in elderly people over 60 years old. The main change was that the lamina propria glands were reduced in size and number. Hyperplastic CAG accounted for 29.1% (654/2248), mostly occurring between 40 and 60 years old. The main change was that the lamina propria glands were atrophy accompanied by glandular hyperplasia and slight expansion of the glands. IM CAG accounted for 50.4% (1132/2248), most of which increased with age, and were more common in those over 50 years. The atrophy of the lamina propria glands was accompanied by significant IM, and the mucus containing sialic acid or sulfate was distinguished according to the nature of the mucus. The IEN type CAG accounted for 11.4% (257/2248), which developed from the previous types, with severe gland atrophy and reduced mucus secretion, and is an important precancerous lesion.

CONCLUSION

The histological typing of CAG is convenient to understand the property of lesion, determine the follow-up time, and guide the clinical treatment.

Intestinal Chelators, Sorbants, and Gut-Derived Uremic Toxins

Chronic kidney disease (CKD) is a highly prevalent condition and is associated with a high comorbidity burden, polymedication, and a high mortality rate. A number of conventional and nonconventional risk factors for comorbidities and mortality in CKD have been identified. Among the nonconventional risk factors, uremic toxins are valuable therapeutic targets. The fact that some uremic toxins are gut-derived suggests that intestinal chelators might have a therapeutic effect. The phosphate binders used to prevent hyperphosphatemia in hemodialysis patients act by complexing inorganic phosphate in the gastrointestinal tract but might conceivably have a nonspecific action on gut-derived uremic toxins. Since phosphorous is a major nutrient for the survival and reproduction of bacteria, changes in its intestinal concentration may impact the gut microbiota’s activity and composition. Furthermore, AST-120 is an orally administered activated charcoal adsorbent that is widely used in Asian countries to specifically decrease uremic toxin levels. In this narrative review, we examine the latest data on the use of oral nonspecific and specific intestinal chelators to reduce levels of gut-derived uremic toxins.

Lanthanum Deposition in the Gastroduodenal Mucosa of Dialysis Patients

Lanthanum (La) carbonate (LC) is one of the most popular phosphate binders used in dialysis patients with end-stage renal disease. Only a small amount of LC is believed to be absorbed from the gastrointestinal (GI) tract because LC strongly binds to dietary phosphate and forms insoluble complexes. La deposition in the gastroduodenal mucosa has been recently identified. Endoscopically, La deposition is demonstrated as whitish lesions of varying sizes and shapes in the gastroduodenal mucosa. Microscopically, La deposition is characterized by histiocytic reaction or small foreign body granulomas containing gray or brown materials mainly in the lamina propria of the GI mucosa. Some histiocytes containing La can migrate into regional lymph nodes via the lymphatic flow. The amount of La deposition in the gastroduodenal mucosa is correlated with the total dose of LC administration, and La deposition is almost consistently observed in LC-treated dialysis patients. Although the detailed mechanism of La deposition in the GI tract is still unclear, several factors, such as gastric pH and metaplastic change of the mucosal epithelium, may be involved in the La deposition in the gastroduodenal mucosa. Here we present an overview of the feature of La deposition in the GI tract.

Phosphate binders in chronic kidney disease: an updated narrative review of recent data

Chronic kidney disease (CKD) is frequently accompanied by hyperphosphatemia. High serum phosphate usually requires dietary measures, adequate dialysis prescription and/or phosphate binders. For this narrative review a PubMed searched was undertaken to identify new publications on phosphate binders that had been published between January 2015 and July 2019. The present review summarizes this most recent information on dietary measures and their problems in treating hyperphosphatemia in CKD patients, overall effects of phosphate binders on cardiovascular mortality and morbidity, adherence to phosphate binder therapy as well as new data on specific aspects of the various phosphate binders on the market: calcium-containing phosphate binders, polymeric phosphate binders (sevelamer, bixalomer, colestilan), magnesium-containing phosphate binders, lanthanum carbonate, ferric citrate, sucroferric oxyhydroxide, and new compounds in development, in particular drugs targeting intestinal phosphate transporters.

Utility of Scanning Electron Microscopy Elemental Analysis Using the 'NanoSuit' Correlative Light and Electron Microscopy Method in the Diagnosis of Lanthanum Phosphate Deposition in the Esophagogastroduodenal Mucosa

BACKGROUND

We have recently developed the correlative light and electron microscopy of hematoxylin and eosin (H&E)-stained glass slides using the 'NanoSuit' method. The aim of this study is to explore the utility of the new NanoSuit-correlative light and electron microscopy method combined with scanning electron microscopy-energy dispersive X-ray spectroscopy elemental analysis for the diagnosis of lanthanum phosphate deposition in the H&E-stained glass slides.

METHODS

Nine H&E-stained glass slides of the upper gastrointestinal tract mucosa containing the brown pigmented areas by light microscopic observation, which were suspected as lanthanum phosphate deposition, were observed and analyzed by scanning electron microscopy-energy dispersive X-ray spectroscopy using the NanoSuit-correlative light and electron microscopy method.

RESULTS

In all nine slides, the new NanoSuit-correlative light and electron microscopy method combined with scanning electron microscopy-energy dispersive X-ray spectroscopy revealed the accumulation of both lanthanum and phosphorus in the tissue area corresponding to the brown pigment deposition. In addition to the existence of lanthanum phosphate in the stomach and duodenum, known target organs, we observed deposition in the esophagus for the first time. Furthermore, we observed lanthanum phosphate deposition in the background mucosa of stomach containing primary adenocarcinoma.

CONCLUSIONS

Scanning electron microscopy-energy dispersive X-ray spectroscopy analysis using the NanoSuit-correlative light and electron microscopy method is useful for the diagnosis of lanthanum phosphate deposition in the H&E-stained glass slides. Lanthanum phosphate deposition occurs not only in the stomach and duodenum but also in the esophagus.

Frequent Involvement of the Duodenum with Lanthanum Deposition: A Retrospective Observational Study

Objective This study aimed to investigate the endoscopic features of lanthanum-associated duodenal lesions and the prevalence of duodenal involvement among patients with pathologically proven lanthanum deposition in the gastrointestinal tract. Methods We retrospectively reviewed 24 patients with pathologically proven lanthanum deposition in the gastrointestinal tract. Patients were subdivided into three groups: Group A, patients with pathologically-proven lanthanum deposition in the duodenum; Group B, patients without lanthanum deposition in the duodenum; and Group C, patients without a biopsy of the duodenum. Results A biopsy examination of the duodenum was performed in 19 patients, and lanthanum deposition was detected in 17 patients (17/19, 89.5%). In group A (n=17), whitish duodenal villi were detected in 15 patients during esophagogastroduodenoscopy (15/17, 88.2%). While the other two patients showed no whitish villi, a biopsy of the duodenal mucosa revealed lanthanum deposition. The deposition of a white substance showing a clear margin was visible within multiple villi under magnified observation in some patients of group A. Group B patients (n=2) also showed whitish villi. However, the whitish color was faint in one case and sparse in the other case. Conclusion Lanthanum deposits in the duodenum may resemble white villi. However, in some cases, these deposits may be unrecognizable during esophagogastroduodenoscopy due to the subtle degree of deposition. Endoscopists should biopsy the duodenum as well as the stomach, regardless of the presence or absence of white villi, for an accurate determination of lanthanum deposition in the gastrointestinal tract.

Lanthanum deposition corresponds to white lesions in the stomach

OBJECTIVE

Although lanthanum deposition in the stomach has been most frequently reported to occur as white lesions, no study has investigated whether the white lesions observed during esophagogastroduodenoscopy are truly lanthanum-related. Here, we retrospectively investigated the amount of lanthanum in endoscopic biopsy specimens.

METHODS

We reviewed four patients showing gastric white spots or annular whitish mucosa in the gastric white lesions (Bw) and peripheral mucosa where the white substance was not endoscopically observed (Bp) during biopsy. We also reviewed three patients with diffuse whitish mucosa and three patients with no whitish lesions. We performed scanning electron microscopy and energy dispersive X-ray spectrometry to quantify the lanthanum elements (wt%) in the biopsy specimens.

RESULTS

The amount of lanthanum in the Bw ranged from 0.15-0.31 wt%, whereas that of Bp was 0.00-0.13 wt%. The difference was statistically significant (P < 0.05). The amount of lanthanum in the Bw, endoscopically presented with white spots or annular whitish mucosa, was significantly higher than that of no whitish lesions (0.05-0.14 wt%, P < 0.05). The amount of lanthanum was also higher in the diffuse whitish mucosa (0.21-0.23 wt%) compared with no whitish lesions (P < 0.01).

CONCLUSIONS

This study is the first to reveal that pathological lanthanum deposition corresponds to the endoscopically observed white lesions in the gastric mucosa. Therefore, during esophagogastroduodenoscopy, physicians should pay attention to possible presence of white lesions in patients treated with oral lanthanum carbonate to ensure prompt identification of associated issues.