The augmented histamine test with special reference to achlorhydria

Should peri-gastrectomy gastric acidity be our focus among gastric cancer patients?

AIM: To investigate the necessity and correctness of acid suppression pre- and post-gastrectomy among gastric carcinoma (GC) patients.

METHODS: From June 2011 to April 2013, 99 patients who were diagnosed with GC or adenocarcinoma of the gastroesophageal junction (type II or III) and needed surgical management were enrolled. They all underwent gastrectomy by the same operators [35 undergoing total gastrectomy (TG) plus Roux-en-Y reconstruction, 34 distal gastrectomy (DG) plus Billroth I reconstruction, and 30 proximal gastrectomy (PG) plus gastroesophagostomy]. We collected and analyzed their gastrointestinal juice and tissues from the pre-operational day to the 5^th day post-operation, and 6 mo post-surgery. Gastric pH was detected with a precise acidity meter. Gastric juice contents including potassium, sodium and bicarbonate ions, urea nitrogen, direct and indirect bilirubin, and bile acid were detected using Automatic Biochemical Analyzer. Data regarding tumor size, histological type, tumor penetration and tumor-node-metastasis (TNM) stage were obtained from the pathological records. Reflux symptoms pre- and 6 mo post-gastrectomy were evaluated by reflux disease questionnaire (RDQ) and gastroesophageal reflux disease questionnaire (GERD-Q). SPSS 16.0 was applied to analyze the data.

RESULTS: Before surgery, gastric pH was higher than the threshold of hypoacidity (4.25 ± 1.45 vs 3.5, P = 0.000), and significantly affected by age, tumor size and differentiation grade, and potassium and bicarbonate ions; advanced malignancies were accompanied with higher pH compared with early ones (4.49 ± 1.31 vs 3.66 ± 1.61, P = 0.008). After operation, gastric pH in all groups was of weak-acidity and significantly higher than that pre-gastrectomy; on days 3-5, comparisons of gastric pH were similar between the 3 groups. Six months later, gastric pH was comparable to that on days 3-5; older patients were accompanied with higher total bilirubin level, indicating more serious reflux (r = 0.238, P = 0.018); the TG and PG groups had higher RDQ (TG vs DG: 15.80 ± 5.06 vs 12.26 ± 2.14, P = 0.000; PG vs DG: 15.37 ± 3.49 vs 12.26 ± 2.14, P = 0.000) and GERD-Q scores (TG vs DG: 10.54 ± 3.16 vs 9.15 ± 2.27, P = 0.039; PG vs DG: 11.00 ± 2.07 vs 9.15 ± 2.27, P = 0.001) compared with the DG group; all gastric juice contents except potassium ion significantly rose; reflux symptom was significantly associated with patient’s body mass index, direct and indirect bilirubin, and total bile acid, while pH played no role.

CONCLUSION: Acidity is not an important factor causing unfitness among GC patients. There is no need to further alkalify gastrointestinal juice both pre- and post-gastrectomy.

Measurement of gastric hydrochloric acid after maximal histamine stimulation with special reference to achlorhydria

Titration to different pH end points was performed in all samples of gastric juice from 208 patients with gastro- instestinal diseases and healthy persons, examined with the augmented histamine test. Titration to pH 3.3 and to pH 7.0 revealed differences in hydrogen ion concentration, which were significantly negatively correlated to the maximal acid output, calculated from the acidity at pH 3.3. Differences between maximal acid outputs, calculated from the acidities at pH 3.3 and pH 7.0, varied only little in all examined groups with the exception of gastric juice contaminated by food. Titration to pH 7.0 or higher overestimates gastric hydrochloric acid, especially in gastric juice from patients with gastritis and gastric juice contaminated by food. The results of this study support previous investigations, which recommend titration of gastric juice to pH 3.5 with simultaneous measurement of pH. Achlorhydria corresponding to absence of parietal cells is hereby defined by a pH higher than 3.5 and a pH fall less than one pH unit from basal to maximally stimulated values.

Malabsorption of vitamin B12 in dermatitis herpetiformis and its association with pernicious anaemia

Serum vitamin B12 concentrations were determined in 129 patients and a pentagastrin test performed in 116 patients with dermatitis herpetiformis (DH). Low serum vitamin B12 levels were found in 27 patients (21%) and achlorhydria in 30. Forty-two patients with achlorhydria and/or vitamin B12 deficiency were subjected to further haematological and gastrointestinal investigations. Functional or morphological involvement of the small intestine was seen in almost all patients with vitamin B12 deficiency but, in addition, atrophic gastritis resulting in defective secretion of intrinsic factor (pernicious anaemia) was found in 8 cases (7% of all DH patients). Thus, a low vitamin B12 level in DH patients should result in a careful gastrointestinal examination as both an atrophic gastritis and a coeliac-like enteropathy have further clinical implications.

Optimizing acid suppression for treatment of acid-related diseases

Gastric acid is of central importance in the pathogenesis of duodenal ulcer, gastric ulcer, and gastroesophageal reflux disease. Pharmacological reduction of acid secretion is, therefore, the mainstay of current treatment, but the optimal degree of acid suppression remains incompletely understood. This paper considers the ideal ways of assessing and reporting the pharmacological effectiveness of acid-inhibiting drugs and relating such data to clinical efficacy. Twenty-four-hour intragastric pH measurements are widely used for this purpose, although this technique cannot measure secretion quantitatively. Data on suppression of 24-hr intragastric acidity for groups of subjects have been successfully correlated with healing rates for duodenal ulcer, gastric ulcer, and gastroesophageal reflux disease. Three primary determinants of healing have been derived from antisecretory data. These are the degree of suppression of acidity, the duration of suppression of acidity, and the duration of treatment. The order of importance of these determinants varies depending on the disease. Data on 24-hr intragastric acidity should be accompanied whenever possible by data on 24-hr plasma gastrin levels, as the relationship between suppression of acidity and a rise in gastrin varies widely between individuals. It is not possible to predict the plasma gastrin level from the intragastric pH or any other measurement of intragastric acidity. Comparative data sets in groups of subjects may provide useful information. Proton pump inhibitors produce a greater and longer-lasting degree of suppression of acidity than conventional doses of H2-receptor antagonists. For this reason, they are more effective in healing duodenal ulcer and gastric ulcer. However, in view of the importance of duration of treatment, healing rates with the H2-receptor antagonists approach those obtained with proton pump inhibitors if treatment is continued for a longer time. In gastroesophageal reflux disease in particular, although the optimal degree of acid suppression is not yet defined, the consistently superior performance of proton pump inhibitors demonstrates that increased suppression of acidity is clinically beneficial.

Fasting gastric pH and its relationship to true hypochlorhydria in humans

Abnormally low rates of gastric acid secretion (hypochlorhydria) are associated with bacterial overgrowth, enteric infection, and with hypergastrinemia and an increased risk of gastric neoplasms. In the present study, we evaluated the ability of fasting gastric juice pH measurements to detect true hypochlorhydria. True hypochlorhydria was defined as a peak acid output in response to a maximally effective stimulant of acid secretion that was below the lower limit of normal for 365 consecutive healthy subjects. In these healthy subjects, average basal pH was 2.16 +/- 0.09 in men and 2.79 +/- 0.18 in women. In 109 consecutive experiments in 28 subjects with true hypochlorhydria, fasting gastric pH averaged 7.44 +/- 0.11 in men and 7.65 +/- 0.33 in women. Fasting pH exceeded the upper 95% confidence limit of normal (5.09 in men and 6.81 in women) in 102 of the 109 experiments (94%). Thus, fasting pH measurement was a sensitive method for diagnosing bona fide hypochlorhydria.

A technique for screening of achlorhydria and hypochlorhydria during upper gastrointestinal endoscopy

Measuring of the intragastric pH during upper gastrointestinal endoscopy examination was performed perendoscopically with a monocrystalline antimony electrode, which was passed through the biopsy channel of the endoscope. The procedure was easily performed, resulting in only a few minutes' delay. If the pH found was 3.5 or above, the patients were later sent for a subcutaneous pentagastrin aspiration test. There was a close correlation between the lowest intragastric pH measured via the endoscope and the lowest pH measured in the gastric juice aspirated under basal conditions (r = 0.673, p less than 0.0001). An endoscopically assessed pH of 4.0 was the lowest level above which patients with achlorhydria or hypochlorhydria were found, according to the subsequent pentagastrin test. Fifty-five per cent of the patients with a perendoscopically assessed pH of 4.0 or above were achlorhydric.

Gastric vascular ectasias in cirrhosis: association with hypoacidity not related to gastric atrophy

To investigate whether hypergastrinemia and low serum levels of pepsinogen I are associated with gastric hypoacidity in cirrhosis with capillary ectasia of gastric mucosa and whether this alteration is secondary to the presence of atrophic gastritis, two groups of patients were studied: 1) 12 cirrhotic patients with diffuse gastric red spots at the endoscopic examination, and 2) 12 cirrhotic patients with endoscopically normal mucosa. Vascular ectasia of the gastric mucosa was histologically confirmed in all patients with gastric red spots. The study of base-line and stimulated acid gastric secretion showed that 9 of 12 (75%) cirrhotics with gastric vascular ectasia had achlorhydria and that 8 of these 9 patients had high base-line gastrin serum levels (greater than 130 pg/ml) and low base-line pepsinogen I serum levels (less than 20 ng/ml). Base-line gastrin and pepsinogen I serum levels were significantly greater and lower, respectively, in patients with gastric vascular ectasias than in cirrhotics without these lesions. None of the patients of either group had complete atrophy in the corpus of the stomach, and only 4 of the 9 cirrhotics with gastric vascular ectasia and achlorhydria had moderate atrophy. These results show that achlorhydria is frequently associated with hypergastrinemia and low pepsinogen I serum levels in patients with cirrhosis and gastric vascular ectasias and suggest that this disturbance is not secondary to a morphologic abnormality of the gastric mucosa.

Treatment with cimetidine, antacid, or placebo in patients with dyspepsia of unknown origin

Patients with dyspepsia of unknown origin were randomly allocated to a controlled double-blind study to examine the symptomatic effect of cimetidine and antacid especially on the relief of pain, nausea, and bloating. Two hundred and twenty-two patients with no previous history of peptic ulcer disease and no evidence of other organic causes of dyspepsia were treated for 6 weeks with placebo, cimetidine, or antacid. The results showed that cimetidine was superior to both placebo and antacid in relieving pain and nausea but not bloating. Certain background factors, such as epigastric pain and symptoms relieved by solid food, had a significant positive influence on the outcome of treatment. When the impact of background factors was taken into account, cimetidine was found to be more effective than both placebo and antacid also with regard to the number of patients who improved in general well-being.

Gastric cancer risk in achlorhydric patients. A long-term follow-up study

Achlorhydria, determined by the augmented histamine test, is the functional expression of the most severe atrophic gastritis and is followed by a 4- to 6-fold increased risk of gastric cancer, as we found 5 cancers in 114 patients after a mean observation period of 8.4 years. The cancers developed from 1 to 17 years after achlorhydria diagnosis--three cases after more than 9 years. The study showed no difference in gastric cancer risk between patients with and without pernicious anaemia. Spontaneous achlorhydria is the late result of atrophic gastritis, which should be regarded the premalignant condition. The development of gastric cancer from pharmacologically reduced acid secretion must be regarded as highly hypothetical, since this is not followed by atrophic gastritis.

Liberation of hydrogen from gastric acid following administration of oral magnesium

We are in the process of developing a noninvasive test for gastric acid secretion based on the reaction of orally administered magnesium metal with gastric acid: Mg + 2HCl in equilibrium with MgCl2 + H2. We hypothesized that the hydrogen gas thus evolved could be detected in exhaled air and belches and that the amount of hydrogen released could be related to the amount of acid in the stomach. To validate this hypothesis, we gave magnesium to two groups of young adult volunteers following either betazole stimulation or cimetidine inhibition of acid secretion. In group I we gave subcutaneous betazole and gave magnesium in doses from 10 to 200 mg. In group II we gave oral betazole and used a constant dose of 150 mg of magnesium. In both groups we consistently detected significant increases in breath and belch hydrogen following magnesium in the betazole-stimulated volunteers. This response was blocked by cimetidine. The magnitude of the response was related to the magnesium dose, with 150 mg appearing to induce a maximum response. Administration of oral magnesium up to 200 mg was not associated with any untoward effects. We conclude that magnesium led to the release of hydrogen gas in vivo and that the quantity of hydrogen gas recovered was related to the amount of gastric acid. With further development, this principle might be used to develop a simple noninvasive test for gastric acid secretion.

Hydrogen (H2) breath test and gastric bacteria in acid-secreting subjects and in achlorhydric and postgastrectomy patients before and after antimicrobial treatment

Sixteen patients with pentagastrin-fast achlorhydria and 12 patients who had undergone Billroth II gastrectomy (at least 3 years previously) were compared with 10 acid-secreting volunteers and 13 patients with endoscopically proven peptic disease. The concentration and type of gastric bacteria were analysed in achlorhydrics, Billroth II patients, and patients with peptic disease. A 6-h hydrogen (H2) breath test after a standardized meal was performed in all subjects. The mean concentration of gastric bacteria was significantly higher in achlorhydrics and Billroth II patients than in patients with peptic disease. End-expiratory H2 excretion was elevated in achlorhydrics and Billroth II patients to levels significantly exceeding those of acid-secreting volunteers and patients with peptic disease. In achlorhydrics, total bacterial concentration in gastric juice was correlated to H2 excretion between 60 and 180 min after the meal. Treatment of achlorhydric and postgastrectomy patients with trimethoprim/sulphamethoxazole lowered H2 breath concentrations in both groups and reduced symptoms in achlorhydrics. Elevated end-expiratory H2 levels after a test meal indicate upper gastrointestinal bacterial overgrowth in achlorhydrics and in postgastrectomy patients.

Gastric morphology and function in dermatitis herpetiformis and in coeliac disease

Gastric acid secretory capacity was evaluated in 116 patients with dermatitis herpetiformis by means of the pentagastrin test. Endoscopic gastric mucosal biopsy specimens were obtained from both the body and the antrum in 90 of them. Forty-eight patients (41%) had a maximal acid output less than 10 mmol/h, and 30 of them (26%) were achlorhydric. The frequency of achlorhydria increased with age, and 27 out of 58 patients (47%) more than 50 years old were achlorhydric. Antrum-sparing chronic atrophic gastritis was present in 92% of the achlorhydric patients, and hypergastrinaemia and serum parietal cell antibodies were found in most of them. The prevalence of chronic gastritis of the body and of the antrum increased with age. There was no correlation between atrophic gastritis or achlorhydria and small-intestinal villous atrophy, the results of the D-xylose test, and blood folate and serum zinc determinations. The transferrin saturation index was lower in patients with achlorhydria. The frequency of achlorhydria was significantly higher in patients with dermatitis herpetiformis than in 69 patients with coeliac disease.

Haematological aspects of life with an ileostomy

The haematological aspects of life with an ileostomy have been studies in 51 patients, of whom 39 had had ulcerative colitis and 12 had Crohn's disease. The findings in these patients have been compared with those in 39 healthy volunteers who were matched for age and sex with the 39 patient who had had ulcerative colitis. There was evidence of a mild degree of iron deficiency in the patients with an ileostomy. This was partly due to a pre-existing iron deficiency resulting from their preceding illness and operation, as the abnormality was less pronounced in the patients in whom the ileostomy had been established for more than 3 years. There was some evidence of excessive iron loss and a controlled trial of ferrous fumurate showed that the iron deficiency was largely corrected by this means. Circulating levels of vitamin B12 were normal, but it is relevant that some of the Crohn's disease group were receiving parenteral supplements. The absorption of vitamin B12 wa low in the patients with Crohn's disease who had had an ileal resection of more than 17 cm. The absorption of vitamin B12 in the patients who had had ulcerative colitis was increased and possible mechanisms are discussed. All but one of the patients had normal levels of plasma folate and in all the red cell blood folate was normal, which can be taken as an indication of a good dietary intake and adequate absorption.

Inhibitory effect of eggs on vitamin B12 absorption: description of a simple ovalbumin 57Co-vitamin B12 absorption test

Ovalbumin and egg yolks, mixed separately in vitro with radiocyanocobalamin (57 Co-vitamin B12), were served to normal volunteers in a cooked form. Ovalbumin, and to a lesser degree, egg yolks were observed to inhibit vitamin B12 absorption. This observation explains the rather poor assimilation of vitamin B12 from eggs labelled in vivo with 57 Co-vitamin B12.

Parietal cell antibodies. Part I. Clinical and pathological studies of parietal cell antibodies

The incidence of parietal cell antibodies (P.C.A.) in patients with various diseases was investigated by complement fixation test (C.F.T.). The relationship between the incidence of P.C.A. and clinical and pathological findings was also investigated. The incidence of P.C.A. with simple atrophic gastritis was 34.8% in total cases, 29.0% in male and 48.1% in female, respectively. The difference between the sexes was statistically significant (p less than 0.05). The incidence of P.C.A. in superficial gastritis was 37.5%, showing the same incidence as atrophic gastritis. The difference between the two groups was not statistically significant (p less than 0.05). The incidence in patients with hypo- and hyperactivity was 43.0% and 11.8%, respectively. The difference was statistically significant, but that between hypo- and normoacidity was not significant (p less than 0.05). The author postulated the conclusion that the superficial gastritis could be included in the category of atrophic gastritis. The dissociation of correlation of titer of C.F.T. with acidity and histological findings was found. The correlation was more significantly observed with acidity than with histological findings. The relatively high incidences of P.C.A. were noted in patients with peptic ulcer, gastric carcinoma and chronic thyroiditis. The incidence of P.C.A. in other diseases showed the nearly equal incidence to that of other investigators. Three cases of postgastrectomy patients were noted, in which the P.C.A. disappeared four to six months after total or subtotal gastrectomy.

Factors affecting maximal acid secretion

The mechanisms by which different factors affect the maximal acid secretion of the stomach are discussed with particular reference to nationality, sex, age, body weight or lean body mass, procedural details, mode of calculation, the nature, dose and route of administration of a stimulus, the synergistic action of another stimulus, drugs, hormones, electrolyte levels, anaemia or deficiency of the iron-dependent enzyme system, vagal continuity and parietal cell mass.

Aetiological factors in chronic atrophic gastritis

Images

THE ABSORPTION OF RADIOACTIVE VITAMIN B12 AND THE SECRETION OF HYDROCHLORIC ACID IN PATIENTS WITH ATROPHIC GASTRITIS

Images