Gastric function and histology in chronic renal failure

The effects of continuous ambulatory peritoneal dialysis and hemodialysis on serum pepsinogen concentrations in patients with chronic renal failure

Pepsinogen, the precursors of pepsin, is classified into two subtypes: pepsinogen I (PG I) and pepsinogen II (PG II). Patients with impaired renal function are associated with elevated concentrations of serum pepsinogen. Contradictory results have been reported about the effect of dialysis on the serum pepsinogen levels, as the previous studies were conducted only in a particular period of dialysis. We therefore investigated the effect of continuous ambulatory peritoneal dialysis (CAPD) or hemodialysis on serum pepsinogen levels in patients with chronic renal failure (CRF) before and after dialysis treatment. Thirty-four patients with CRF were enrolled in this study and were treated by CAPD (n=22) or hemodialysis (n=12). As a control group, subjects with normal renal function were included (n=20). Serum PG I and PG II levels were measured in control subjects and CRF patients before dialysis treatment and after three-month dialysis treatment. Before dialysis treatment, serum PG I levels were significantly higher in CRF patients than control subjects. In patients treated by CAPD, the serum PG I levels were significantly decreased but its levels were still higher than the values of the control subjects, whereas PG I levels remained unchanged in patients treated by hemodialysis. There were no differences in serum PG II levels between control subjects and CRF patients before or after dialysis treatment. Thus, CAPD is more effective than hemodialysis in the clearance of PG I.

Gastrointestinal complications of renal failure

ESRD has well-documented effects on the esophagus, stomach, duodenum, and pancreas. Unless the supply of donor kidneys increases dramatically, these complications of ESRD will continue to be an important clinical issue for gastroenterologists given the large percentage of patients with symptoms. Further study of uremic retention products and abnormal gastrointestinal hormone profiles on the gastrointestinal tract should help provide additional insights into this complex group of patients.

Value of assessing parathyroid hormone-like activity in a case of extreme hypercalcaemia

A previously well 70 year old woman was admitted to hospital following a three day history of vomiting and confusion. Her serum calcium was 6.58 mmol/l, phosphate 1.09 mmol/l, and alkaline phosphatase 91 iu/l. The mechanism of this hypercalcaemia was not obvious as there was no evidence of a primary malignancy, lymphadenopathy or hepatosplenomegaly. The calculation of indices of urinary excretion of calcium and phosphate suggested the presence of excessive parathyroid hormone (PTH) activity as the mechanism of hypercalcaemia. Plasma intact PTH, 25-hydroxycholecalciferol, and 1,25-dihydroxycholecalciferol were not raised suggesting the presence of PTH related peptide (rP). This led to a systematic search for a malignancy, which revealed the presence of a high grade B cell non-Hodgkin's lymphoma confined to the bone marrow. Plasma PTH-rP was subsequently shown to be raised confirming the interpretation of the initial urinary and calcium excretion indices. This case highlights the value of standard laboratory measurements such as urinary calcium and phosphate excretion in cases of hypercalcaemia of obscure aetiology, which can complement measurements of PTH and other calcitropic hormones.

Neuroendocrine cell hyperplasia in colonic tissue used for long term augmentation cystoplasty

A case is described of neuroendocrine cell hyperplasia in intravesical colonic mucosa, implanted previously during augmentation cystoplasty. The patient was a 28 year old man born with posterior urethral valves, a non-functioning right kidney, and a poorly functioning dilated left kidney. The hyperplasia consisted of pure neuroendocrine acini and tubules within the lamina propria, separate from the normal intestinal glands. Adjacent intraepithelial colonic neuroendocrine cells were increased diffusely. Rectal biopsy and previous biopsies of intravesical colonic tissue contained normal neuroendocrine cell populations. Implantation of gut segments into the urinary tract predisposes to late neoplasia, but there is only one report of carcinoid tumour in uroenteric tissue. Intestinal neuroendocrine cell hyperplasia usually occurs diffusely rather than as aggregates, except when associated with adjacent carcinoid tumour. Both diffuse and nodular hyperplasia were present in this case, with an unusual and striking morphology. This is the first report of neuroendocrine cell hyperplasia in gastrointestinal tissue implanted into the urinary tract; this raises the possibility of a risk of late carcinoid tumour in uroenteric segments.

Biopsy specimen appearances of ischaemic gastritis in splanchnic arterial insufficiency

A 74 year old man presented with a one month history of epigastric discomfort, anorexia, weight loss, and postprandial vomiting. The diagnosis of ischaemia was made on endoscopic biopsies from the stomach and duodenum. He was too ill for major vascular surgery and died eight days after admission. Postmortem examination confirmed the diagnosis of splanchnic arterial insufficiency caused by atheroma and thrombosis. Ischaemic gastritis is rare but could easily be missed in unrepresentative biopsy specimens. Prompt diagnosis with revascularisation surgery is the only hope for long term survival.

Sample dilution to resolve mistaken identification of haemoglobin D as haemoglobin E using the variant automated system

High performance liquid chromatography (HPLC) is increasingly being used to estimate variant haemoglobins. A case of haemoglobin S/D (HbS/D) is presented, which was misdiagnosed as haemoglobin S/E (HbS/E) by HPLC. The patient was a 22 year old woman with sickle cell anaemia. Subsequent haemodilution by blood transfusion clearly elucidated the haemoglobin D peak on HPLC. Sample dilution experiments, using the pretransfusion sample, were done resulting in correct elution of the peak in the D window. Troubleshooting in similar problematic haemoglobin variant peaks seen on HPLC can be done by sample dilution.

Necrosis of the gastrointestinal tract in uremic patients as a result of sodium polystyrene sulfonate (Kayexalate) in sorbitol: an underrecognized condition

Sodium polystyrene sulfonate (Kayexalate) in sorbitol given as an enema or orally to treat hyperkalemia has been reported to induce intestinal necrosis in uremic patients. We studied the clinical and pathologic features of 15 patients in whom Kayexalate crystals were observed in specimens from gastrointestinal surgical resections (n = 9) or endoscopic biopsies (n = 7). Oral or nasogastric tube administration of Kayexalate in sorbitol was documented in 10 patients. Among 12 patients with colorectal specimens, necrosis was observed in nine patients (75%), represented by seven of eight surgical resection specimens and three of five endoscopic biopsy specimens. No other cause of colorectal necrosis apart from Kayexalate in sorbitol was apparent in seven patients, and four also had necrosis of the small intestine. Four patients with colonic necrosis in their initial resection specimen developed progressive necrosis of the small intestine or rectum, and five patients (56%) had fatal outcome within 1 day to 6 weeks. Kayexalate crystals were observed in upper gastrointestinal tract specimens from four patients, including one with hemorrhagic gastritis. Our findings provide additional evidence that Kayexalate in sorbitol administered orally or by nasogastric tube can produce necrosis in the gastrointestinal tract.

Gastric and pancreatic functions in haemodialyzed patients

The aim of this work was to assess gastric acid secretion in relation to morphological and histological changes in the gastric mucosa as well as prevalence of Helicobacter pylori in chronically haemodialyzed uraemic patients. Exocrine pancreatic functions after secretin-cerulein test were also studied. In haemodialyzed patients low basal gastric acid output was found, whereas peak output after pentagastrin stimulation did not differ significantly when compared to controls. Endoscopy of gastric and duodenal mucosa revealed inflammatory changes in the majority of patients, described histologically as chronic gastritis with duodenitis. Helicobacter pylori antigen was detected in the serum of 45% of uraemic patients. Serum amylase activity was elevated in haemodialyzed patients relative to controls. Although clinically asymptomatic, haemodialyzed patients exhibited various degrees of gastrointestinal mucosal abnormalities and impairment in exocrine pancreatic functions, mainly low stimulated bicarbonate and protein output as well as low electrolyte concentrations in duodenal content.

Effects of hypochlorhydria and hypergastrinemia on structure and function of gastrointestinal cells. A review and analysis

Since hypochlorhydria can induce hypergastrinemia, and gastrin has a trophic effect on some gastrointestinal cells, states that cause elevated plasma gastrin levels are of interest in terms of effects on cell growth and function. This article reviews the relationship between gastric mucosal cells during periods of acid stimulation and inhibition and analyses the effects of hypochlorhydria and hypergastrinemia on gastric and colonic cells and tumors. Hypochlorhydria releases the inhibitory effect of antral gastrin cells, inducing them to release gastrin in the presence of peptides or amino acids in the gastric lumen or in response to antral distension. Gastrin stimulates the oxyntic mucosa, which may lead to hyperplasia of enterochromaffin-like cells, resulting in enterochromaffin-like carcinoid tumors in aged rats and, rarely, in patients with chronic atrophic gastritis or gastrinomas. In addition to hypergastrinemia, other factors appear to be required for the progression of enterochromaffin-like hyperplasia to carcinoids; genetic factors may be involved. Gastrin elevations due to antisecretory drug therapy are indirectly proportional to the degree of acid inhibition and are reversible upon cessation of therapy. The gastrin levels during omeprazole therapy are similar to those caused by gastric vagotomy. Available evidence does not support a relationship between hypergastrinemia and the occurrence or growth of gastric carcinoma or colonic tumors.

The gastrointestinal tract in uremia

Gastrointestinal mucosal abnormalities ranging from edema to ulceration occur in two thirds of patients dying of uremia. Early studies suggested that uremic patients on maintenance dialysis treatment were at increased risk of peptic ulceration but more recent data indicate that this is not so. Other gastrointestinal problems reported for uremic subjects on maintenance dialysis treatment include bleeding from telangiectatic lesions, constipation, mucosal deposition of amyloid and acute pancreatitis. Nausea and vomiting are common in the uremic patient but gastric emptying studies have yielded conflicting results. Patients undergoing renal transplantation are at increased risk of development of esophagitis, complicated peptic ulcer, intestinal ulceration, and perforation as well as acute pancreatitis.

Gastroduodenal mucosa in uraemia: endoscopic and histological correlation and prevalence of helicobacter-like organisms

This study aimed to determine the prevalence of endoscopic and histological gastroduodenitis as well as helicobacter-like organisms in patients with end stage renal failure undergoing maintenance dialysis treatment. A total of 322 out of 422 patients in our dialysis programme underwent endoscopy and gastroduodenal biopsy specimens were taken from 260. Endoscopic gastroduodenitis occurred in 158 (49%). Histological gastritis occurred in the gastric body or antrum in 134 patients (52%) and duodenitis in 52 (21%). There was no correlation between endoscopic and histological gastritis in contrast to a significant correlation for duodenitis. Helicobacter-like organisms occurred in the body or antrum in 81 (31%). Their presence was associated with gastritis--in particular acute and acute on chronic gastritis rather than chronic gastritis. Patients with gastritis were significantly older than those without (p less than 0.001) and had lower basal and peak acid outputs.

Pathology of digestive organs in renal transplant recipients

A necropsy study of the pathological findings in the digestive system of 19 renal transplant recipients revealed that gastrointestinal (GI), hepatobiliary, and pancreatic pathologies are common in renal transplant recipients. Fifteen of the 19 patients studied had GI pathology. Hepatobiliary pathology was the most common finding with all but one of the 19 cases exhibiting one or more abnormalities. Pancreatic abnormalities were less frequent with 11 patients demonstrating normal findings.