Pernicious anemia

Vitamin B-12 deficiency induces anomalies of base substitution and methylation in the DNA of rat colonic epithelium

Derangements of one-carbon metabolism can directly affect the integrity of the genome by producing inappropriate uracil insertion into DNA and by altering patterns of DNA methylation. Vitamin B-12, a one-carbon nutrient, serves as a cofactor in the synthesis of precursors of biological methylation and in nucleotide synthesis. We therefore examined whether vitamin B-12 deficiency can induce these molecular anomalies in the colonic mucosa of rats. Weanling male Sprague-Dawley rats (n = 30) were divided into 2 groups and fed either a vitamin B-12-deficient diet or a similar diet containing adequate amounts of the vitamin. Rats from each group were killed at 6 and 10 wk. Uracil misincorporation into DNA was measured by GC/MS and genomic DNA methylation was measured by LC/MS. Plasma vitamin B-12 concentrations in deficient rats were below detectable limits at 6 and 10 wk; in control rats, concentrations were 0.46 +/- 0.07 and 0.42 +/- 0.10 nmol/L at those times. Although the colon total folate concentration did not differ between the groups, the proportion that was methylfolate was marginally greater in the deficient rats at 10 wk (P = 0.05) compared with control, consistent with the "methylfolate trap" that develops during vitamin B-12 deficiency. After 10 wk, the colonic DNA of the deficient rats displayed a 35% decrease in genomic methylation and a 105% increase in uracil incorporation (P < 0.05). This vitamin B-12-deficient diet, which was of insufficient severity to cause anemia or illness, created aberrations in both base substitution and methylation of colonic DNA, which might increase susceptibility to carcinogenesis.

Oral versus intramuscular cobalamin treatment in megaloblastic anemia: a single-center, prospective, randomized, open-label study

BACKGROUND

Cobalamin (vitamin B12) deficiency, the most common cause of megaloblastic anemia, is treated with intramuscular (IM) cobalamin. It has been suggested by some investigators that oral (p.o.) cobalamin treatment may be as effective in the treatment of this condition, with the advantages of ease of administration and lower cost.

OBJECTIVE

This study assessed the effects and cost of p.o. versus i.m. cobalamin treatment in patients with megaloblastic anemia due to cobalamin deficiency.

METHODS

This was a 90-day, prospective, randomized, open-label study conducted at the Division of Hematology, Department of Internal Medicine, Adnan Menderes University Research and Practice Hospital (Aydin, Turkey). Patients aged > or =16 years with megaloblastic anemia due to cobalamin deficiency were randomized to receive 1000-microg cobalamin p.o. once daily for 10 days (p.o. group) or 1000-microg cobalamin i.m. once daily for 10 days (i.m. group). After 10 days, both treatments were administered once a week for 4 weeks, and after that, once a month for life. Patients were assessed for the presence of reticulocytosis between treatment days 5 and 10 until it was detected. Therapeutic effectiveness was assessed by measuring hematologic parameters on days 0, 10, 30, and 90 and serum vitamin B12 concentration on days 0 and 90. The Mini-Mental State Examination was used before and after the B12 therapy for cognitive function assessment and 125-Hz diapozone was used for vibration threshold testing. Neurologic sensory assessment, including soft-touch and pinprick examinations, was used to identify neuropathy at baseline and study end. Tolerability was assessed using laboratory tests and patient interview. Cost was assessed using the cost of the study drug and of the injection.

RESULTS

Sixty patients completed the study 26 in the p.o. group (16 men, 10 women; mean [SD] age, 60 [15] years) and 34 in the i.m. group (17 men, 17 women; mean [SD] age, 64 [10] years). Reticulocytosis was observed in all patients. In the p.o. group, at days 30 and 90, all hematologic parameters changed significantly versus day 0 (mean hemoglobin levels increased [both P<0.001]; mean corpuscular volume decreased [both P<0.001]; mean white blood cell count increased [day 30, P<0.01; day 90, P<0.001]; and mean platelet count increased [both P<0.001]). The mean serum vitamin B12 concentration increased significantly from day 0 to 90 (P<0.001). These hematologic parameters and the recovery patterns were similar between the 2 groups. Neurologic findings included sensitive peripheral neuropathy in 9 patients (15.0%), alteration of cognitive function (loss of memory, impaired concentration) in 7 patients (11.7%), and loss of sense of vibration in 5 patients (8.3%). Neurologic improvement was detected in 7 of 9 patients (77.8%) in the p.o. group and 9 of 12 patients (75.0%) in the i.m. group at day 30.

CONCLUSIONS

In this study of patients with megaloblastic anemia due to cobalamin deficiency, p.o. cobalamin treatment was as effective as i.m. cobalamin treatment. P.o. treatment also was better tolerated and less expensive compared with IM treatment. However, because of the small sample size and the short term of this study, further long-term studies are needed to determine the efficacy of p.o. cobalamin treatment.

Tumor necrosis factor alpha is not implicated in the genesis of experimental autoimmune gastritis

Experimental autoimmune gastritis (EAG) characterised by mononuclear cell infiltrate, parietal and zymogenic cell destruction and circulating autoantibodies to gastric H(+)/K(+)ATPase is an animal model for human autoimmune gastritis, that leads to pernicious anaemia. We have previously shown that Fas has a role in initiating damage to target cells in EAG. Here we used three strategies to examine the role of TNFalpha in this disease. We administered neutralising anti-TNFalpha antibody either as a single injection or as twice weekly injections for 8 weeks to mice subjected to neonatal thymectomy-induced EAG. To address the role of apoptotic signals through TNFR1, TNFR1 deficient mice were either neonatally thymectomised or crossed to PC-GMCSF transgenic mice that spontaneously develop EAG. Neonatally thymectomised mice treated with anti-TNFalpha antibody developed destructive gastritis and autoantibodies to gastric H(+)/K(+)ATPase similar to control mice. Following either neonatal thymectomy or crossing to PC-GMCSF transgenic mice, TNFR1 deficient mice developed autoantibody-positive destructive gastritis at similar frequency compared with wild type and heterozygous littermates. Our observations that neutralisation of TNFalpha and absence of TNFR1 has no discernible effect on development of EAG suggest that TNFalpha is not required for mucosal cell damage or development of autoimmune gastritis. While blocking TNFalpha activity has therapeutic benefit in certain autoimmune diseases, this is not the case for EAG.

Helicobacter pylori-associated chronic gastritis and unexplained iron deficiency anemia: a reliable association?

BACKGROUND AND AIM

About 35% of iron deficiency anemia cases remain unexplained after a gastrointestinal evaluation. An association between Helicobacter pylori and iron malabsorption has been suggested. The aim of this study was to determine whether H. pylori-associated chronic gastritis is linked to unexplained iron deficiency anemia in adults.

METHODS

From 1996 to 2001, we identified 105 patients with unexplained iron deficiency anemia after upper endoscopy, colonoscopy, small bowel radiographic examination and duodenal biopsies. Two biopsies were obtained from the gastric antrum and two from the corpus of each patient. Gastritis status was described according to the Sydney System and H. pylori infection was assessed by an immunohistochemical test on biopsy specimens. This group was compared to a control group matched for sex and age.

RESULTS

There were 76 women and 29 men (mean age 57.4 +/- 21.4 years) examined in the study. A H. pylori-associated chronic gastritis was identified in 63 cases (60%) vs. 45 cases (43%) cases in the control group (p <.01). Atrophic gastritis was significantly associated with iron deficiency anemia compared with the control group [16 (15%) vs. 6 (6%); p <.03]. In the unexplained iron deficiency anemia group, (1) patients with chronic gastritis were significantly younger (52 +/- 22 vs. 64 +/- 20 years; p <.005), and (2) chronic gastritis was not linked to sex [sex ratio (male/female): 0.5 vs. 0.34, p =.34]. The prevalence of H. pylori infection was similar between premenopausal and postmenopausal women [28 (27%) vs. 26 (25%); p =.7] with iron deficiency anemia.

CONCLUSION

H. pylori infection and chronic gastritis, especially atrophic gastritis, are significantly associated with unexplained iron deficiency anemia. Relationships between H. pylori-associated chronic gastritis and unexplained iron deficiency anemia should be considered.

Helicobacter pylori infection and gastric autoimmune diseases: is there a link?

BACKGROUND

Helicobacter pylori is thought to be involved in atrophic body gastritis. We explored the prevalence of H. pylori infection in asymptomatic subjects with gastric parietal cell antibodies, as well as in patients with pernicious anemia, to evaluate a possible role of H. pylori gastric infection in gastric autoimmunity.

PATIENTS AND METHODS

We studied 79 consecutive asymptomatic subjects with parietal cell antibodies, 24 patients with pernicious anemia, and 66 parietal cell antibody-negative controls. All patients underwent gastric biopsies for histology and detection of H. pylori. Red blood cell count and volume, serum levels of gastrin, pepsinogen I, iron, folic acid, vitamin B12, and circulating antibodies to H. pylori and to intrinsic factor were also determined.

RESULTS

We found an atrophic body gastritis in 14 of the 79 asymptomatic subjects with parietal cell antibodies (18%) and in 2 of the 66 controls (3%) (p =.01). Mean levels of gastrin were increased (p <.0001), while those of pepsinogen were reduced (p <.001) compared with controls. H. pylori was identified at the gastric level and/or circulating anti-H. pylori antibodies were detected in 46 parietal cell antibody-positive subjects (58%) compared with 26 controls (39%) (p =.03). In patients with pernicious anemia we found an atrophic body gastritis in 18 of 24 cases (75%) (p <.001 vs. controls). Mean levels of gastrin were markedly increased (p <.0001) and those of pepsinogen I decreased (p <.0001) relative to controls. Only five of these patients (21%) had evidence of H. pylori infection compared with 46 of the parietal cell antibody-positive subjects (58%) (p =.003) and 26 of the controls (39%). Considering all patients with gastric autoimmunity (i.e. with parietal cell antibodies and/or with pernicious anemia), H. pylori was found in 44 of 72 of those without atrophy (61%) but in 6 of 31 with gastric body atrophy (19%) (p <.001), indicating that H. pylori infection is greatly reduced when gastric acid secretion decreases.

CONCLUSIONS

The frequent detection of H. pylori infection in subjects with early gastric autoimmunity, indicated by the presence of parietal cell antibodies, suggests that H. pylori could have a crucial role in the induction and/or the maintenance of autoimmunity at the gastric level.

Cases from the Osler Medical Service at Johns Hopkins University

A 50-year-old African American woman presented with bilateral lower extremity pain, a history of falls during the past several months, and personality and behavior changes. She had been in good health until approximately 5 months before admission, when she began to fall with increasing frequency, often while going down a flight of stairs. She described these falls as her "legs giving out" and feeling very heavy and unsteady. There was no head trauma or loss of consciousness. Her daughter noticed that her gait had become somewhat unsteady during the last several months. Her family also noted a change in her personality at this time. Previously, she had been a very tidy person who took great care with her appearance, who was working as a customer service representative. However, she had become less social and very withdrawn. She had been observed putting on dirty clothes after showering, as well as eating constantly. The patient denied any fevers, chills, night sweats, headaches, vision changes, or tinnitus. She also denied any rashes, muscle pain, or intolerance to heat or cold. There was no history of seizure disorder or depression. Her past medical history was notable only for hypertension and being a passenger in a motor vehicle crash 1 year before admission. She denied any alcohol, tobacco, or illicit drug use, and had no travel history other than coming to the United States, as she was originally from Trinidad. On physical examination, she was a moderately obese African American woman with a flat affect, psychomotor slowing, and alopecia of the scalp. She was alert and oriented to person, place, and time, but had a score of 26 out of 30 on the Mini-Mental State Examination. She lost points only for recall; she had no difficulty with serial 7s. Her cranial nerves were intact and her speech was fluent, although sparse, and she did not make any paraphasic errors. Her muscle strength was 5/5 in both the upper and lower extremities. Reflexes were 2+ in the upper extremities and 1+ in the lower extremities, and toes were downgoing bilaterally. She had intact sensation to light touch and pinprick, but markedly diminished proprioception of her lower extremities bilaterally. She had a wide-based gait with a positive Romberg sign and was markedly ataxic. Rectal examination yielded a positive guaiac test with brown stool, normal tone, and no masses. The remainder of the physical examination was normal. Laboratory studies revealed pancytopenia with a hematocrit of 22.7% and a mean corpuscular volume of 118.2 fL. A peripheral smear that was performed on admission, prior to transfusion, revealed macrocytic red cells and hypersegmented neutrophils.

Molecular mimicry between Helicobacter pylori antigens and H+, K+ --adenosine triphosphatase in human gastric autoimmunity

Autoimmune gastritis and Helicobacter pylori–associated gastric atrophy develop through similar mechanisms involving the proton pump H⁺,K⁺–adenosine triphosphatase as autoantigen. Here, we report that H. pylori–infected patients with gastric autoimmunity harbor in vivo–activated gastric CD4⁺ T cells that recognize both H⁺,K⁺–adenosine triphosphatase and H. pylori antigens. We characterized the submolecular specificity of such gastric T cells and identified cross-reactive epitopes from nine H. pylori proteins. Cross-reactive H. pylori peptides induced T cell proliferation and expression of T helper type 1 functions. We suggest that in genetically susceptible individuals, H. pylori infection can activate cross-reactive gastric T cells leading to gastric autoimmunity via molecular mimicry.

Chemokine receptor CCR5 is not required for development of experimental autoimmune gastritis

Experimental autoimmune gastritis (EAG) is a model of human autoimmune gastritis, the underlying cause of pernicious anaemia. It is characterised by gastric mononuclear cell infiltrates, destruction of parietal and zymogenic cells, and autoantibodies to parietal cell-associated H(+)/K(+) ATPase. Here, we have investigated the role of CCR5 in the development of EAG. We found that the development of EAG was not prevented in CCR5-deficient mice. Using reverse-transcriptase analysis of stomachs from normal and gastritic mice we found no difference in expression of CCR5 and its chemokine ligands MIP-1alpha, MIP-1beta, and RANTES. We also found that the CCR5 antagonist met-RANTES failed to prevent the development of EAG induced by neonatal thymectomy. These observations suggest that the CC chemokine receptor CCR5 is not essential for development of EAG.

Detection of anti-HAV antibody with dot immunogold filtration assay

AIM: To establish a rapid, sensitive and specific immunogold assay for detection of hepatitis A virus infection.

METHODS: Rabbit monoclonal antibodies to anti-human IgM and IgG (Dako) were dotted on a nitrocellulose membrane (NCM) respectively to capture the human sera IgM and IgG. Then the captured antibodies would conjugate to HAV antigen, which was revealed by mouse anti-HAV IgG conjugated to gold particles. Final results were assessed by blind method.

RESULTS: Sera from 96 patients with acute hepatitis were used for our study. Compared with well-recognized standard (Abbott Laboratory, USA), the sensitivity and specificity of IgM-DIGFA (self-made) were 91.3% (42/46) and 96.0% (48/50), and those of IgM-ELISA (Kehua, Shanghai) were 97.8% (45/46) and 100.0% (50/50). The identical results were produced from the study with reagents at different conditions, and the study was repeated in 15 negative sera and 10 positive sera. The serum anti-HAV IgG was tested with DIGFA at the same time. In comparison with ELISA, the sensitivity and specificity of DIGFA for IgG anti-HAV were 87.2% (41/47) and 91.8% (45/49), respectively.

CONCLUSION: This assay can detect anti-HAV IgM and IgG simultaneously, and be done within 3 min. The simplicity, rapidity and specificity of the assay were useful for screening and epidemiological study.

Gastric autoimmune disorders in patients with chronic hepatitis C before, during and after interferon-alpha therapy

AIM: To explore the prevalence of autoimmune gastritis in chronic hepatitis C virus (HCV) patients and the influence of a-interferon (IFN) treatment on autoimmune gastritis.

METHODS: We performed a prospective study on 189 patients with positive anti-HCV and viral RNA enrolled in a 12-month IFN protocol. We evaluated: a) the baseline prevalence of autoimmune gastritis, b) the impact of IFN treatment on development of biochemical signs of autoimmune gastritis (at 3, 6 and 12 mo), c) the evolution after IFN withdrawal (12 mo) in terms of anti-gastric-parietal-cell antibodies (APCA), gastrin, anti-thyroid, and anti-non-organ-specific antibodies.

RESULTS: APCA positivity and 3-fold gastrin levels were detected in 3 (1.6%) and 9 (5%) patients, respectively, at baseline, in 25 (13%) and 31 (16%) patients at the end of treatment (both P < 0.001, vs baseline), and in 7 (4%) and 14 (7%) patients 12 mo after withdrawal (P = 0.002 and P = 0.01 respectively, vs baseline; P = not significant vs end of treatment). The development of autoimmune gastritis was strictly associated with the presence of autoimmune thyroiditis (P = 0.0001), no relationship was found with other markers of autoimmunity.

CONCLUSION: In HCV patients, IFN frequently precipitates latent autoimmune gastritis, particularly in females. Following our 12-month protocol, the phenomenon generally regressed. Since APCA positivity and high gastrin levels are associated with the presence of antithyroid antibodies, development of autoimmune thyroiditis during IFN treatment may provide a surrogate preliminary indicator of possible autoimmune gastritis to limit the need for invasive examinations.

Benign gastric polyps: morphological and functional origin

The most common types of benign gastric polyps are fundic gland polyps, hyperplastic polyps, and adenomas. The aim of this study was to determine on which morphological and functional background benign gastric polyps develop. The study includes 85 consecutive patients with gastric polyps and sex- and age-matched controls without polyps selected at random from a general population sample. The type of polyp was hyperplastic in 52 (61%), fundic gland in 18 (21%), adenoma in 10 (12%), carcinoid in 2 (2%), hamartoma in 2 (2%), and inflammatory fibroid in 1 (1%) of the cases. Routine biopsies from the gastric corpus and antrum were examined for presence of gastritis and H. pylori. Blood samples were analyzed for H. pylori antibodies, H+,K+-ATPase antibodies, gastrin, and pepsinogen I. Patients with hyperplastic polyps had increased P-gastrin concentrations and S-H+,K+-ATPase antibody titers and decreased S-pepsinogen I concentrations with a high prevalence of atrophic corpus gastritis or pangastritis. A similar pattern was observed among patients with adenomas, whereas patients with fundic gland polyps had normal serology and a lower prevalence of gastritis and H. pylori infection than controls. In conclusion, hyperplastic polyps and adenomas are generally associated with atrophic gastritis. Patients with fundic gland polyps seem to have a sounder mucosa than controls. Whereas the risk of malignant gastric neoplasia is increased in patients with hyperplastic polyps or adenomas, this does not seem to be the case in patients with fundic gland polyps.

The syndrome of food-cobalamin malabsorption revisited in a department of internal medicine. A monocentric cohort study of 80 patients

BACKGROUND: To date, only case reports or small studies have documented the syndrome of food-cobalamin malabsorption in specific populations of patients or situations. In this paper, we present the data from 80 unselected patients with cobalamin deficiency related to food-cobalamin malabsorption. METHODS: We studied 80 patients with well-established food-cobalamin malabsorption who were extracted from an observational cohort study (1995-2000) of 127 consecutive patients with cobalamin deficiency and who were followed in a department of internal medicine. RESULTS: The median age of patients was 66 years and the female to male ratio was 1.2. The mean hemoglobin level was 113+/-27 g/l (range 32-159 g/l) and the mean erythrocyte cell volume was 95.4+/-12.3 fl (range 55-140 fl). Mean serum vitamin B12 and homocysteine levels were 153+/-74 pg/ml (range 35-200 pg/ml) and 20.6+/-15.7 μmol/l (range 8-97 μmol/l), respectively. The main clinical findings noted were peripheral neuropathy (46.2%), stroke (12.5%), confusion or dementia (10%), asthenia (18.7%), leg edema (11.2%), and digestive disorders (7.5%). The commonest associated conditions were atrophic gastritis (39%) with evidence of Helicobacter pylori infection (12.2%) and alcohol abuse (13.7%). Three patients had Sjögren's syndrome and one had systemic sclerosis. Ten percent of all patients were on long-term metformin (10%) and 7.5% on acid-suppressive drugs. Correction of the serum vitamin B12 levels and hematological abnormalities was achieved equally well in all patients treated with either intramuscular or oral crystalline cyanocobalamin. CONCLUSION: This study suggests that food-cobalamin malabsorption may be the leading cause of vitamin B12 deficiency in adults. As other studies have also reported, the condition is often associated with neuro-psychiatric findings and with several other conditions. Oral and parenteral cobalamin appear to be equally effective in correcting serum B12 levels and hematological abnormalities and, in many cases, they also relieve symptoms.

Efficacy of short-term oral cobalamin therapy for the treatment of cobalamin deficiencies related to food-cobalamin malabsorption: a study of 30 patients

BACKGROUND

It has been suggested that oral cobalamin (vitamin (B12)) therapy may be an effective therapy for treating cobalamin deficiencies related to food-cobalamin malabsorption. However, the duration of this treatment was not determined.

PATIENTS AND METHOD

In an open-label, nonplacebo study, we studied 30 patients with established cobalamin deficiency related to food-cobalamin malabsorption, who received between 250 and 1000 microg of oral crystalline cyanocobalamin per day for at least 1 month.

ENDPOINTS

Blood counts, serum cobalamin and homocysteine levels were determined at baseline and during the first month of treatment.

RESULTS

During the first month of treatment, 87% of the patients normalized their serum cobalamin levels; 100% increased their serum cobalamin levels (mean increase, +167 pg/dl; P < 0.001 compared with baseline); 100% had evidence of medullary regeneration; 100% corrected their initial macrocytosis; and 54% corrected their anemia. All patients had increased hemoglobin levels (mean increase, +0.6 g/dl) and reticulocyte counts (mean increase, +35 x 10(6)/l) and decreased erythrocyte cell volume (mean decrease, 3 fl; all P < 0.05).

CONCLUSION

Our findings suggest that crystalline cyanocobalamin, 250-1000 microg/day, given orally for 1 month, may be an effective treatment for cobalamin deficiencies not related to pernicious anemia.

Gastritis and carditis

Dyspepsia is a common clinical problem. Its causes include peptic ulcer disease, gastroesophageal reflux, and functional (nonulcer) dyspepsia. A detailed clinical description of pain does not reliably differentiate the cause. Approximately 80% of gastroscopies are performed for the investigation of dyspepsia. "Gastritis" is diagnosed endoscopically in 59% of all stomachs, although in only 3% are the changes severe. Pathologic examination of unselected gastric biopsy specimens reveals that abnormalities are present in 62-73%, but there is only a weak correlation between endoscopic and histologic findings. For these reasons, it is recommended that endoscopic examination should always be accompanied by biopsy. Ideally, biopsies should be taken in a systematic fashion to include sampling of antrum and corpus. Recent evidence suggests that gastric infection by Helicobacter pylori initially presents as a superficial gastritis. Later it may become atrophic with development of intestinal metaplasia. The onset of atrophic changes may be related to the duration of infection, the strain of the infecting organism, associated dietary factors, or as-yet undefined host factors related to immunity. Persistent superficial gastritis predisposes to duodenal ulcer and gastric mucosa-associated lymphoid tissue lymphoma. Atrophic gastritis predisposes to gastric ulcer and adenocarcinoma. Evidence is accumulating that in some patients, pernicious anemia may be an end result of H. pylori-induced atrophic gastritis. Reactive gastropathy is a relatively common finding in gastric biopsies; in most instances it is associated with either reflux of duodenal contents or therapy with nonsteroidal anti-inflammatory drugs. Lymphocytic gastritis, eosinophilic gastritis, and the gastritis associated with Crohn's disease are distinct morphologic entities. Lymphocytic gastritis and eosinophilic gastritis have a variety of clinical associations. Carditis is a controversial topic: currently opinions are divided as to whether it is the result of gastroesophageal reflux or a proximal extension of H. pylori infection from the remainder of the stomach.

[Vitamin B12 deficiency with normal Schilling test or non-dissociation of vitamin B12 and its carrier proteins in elderly patients. A study of 60 patients]

PURPOSE

Approximately 15% of people over 60 years old have a cobalamin (Cbl) deficiency in relation with a food-cobalamin malabsorption (FCM). But to date, only case reports or small series have been reported. The aim of this study was to describe the clinical characteristics of the FCM in old subjects.

METHODS

Sixty patients, at least 65 years old, presenting a Cbl deficiency related to FCM, were extracted from a cohort study of the Hôpitaux universitaires de Strasbourg, France (n = 169). All these patients had an established diagnosis of Cbl deficiency and met the Carmel's criteria of FCM. Their clinical data were retrospectively analysed.

RESULTS

The median age of the 60 patients was 75 years and the female/male ratio was 2.3. The principal clinical symptoms were peripheral neuropathy (35%), confusion and dementia (30%) and anemia-related manifestations such as asthenia and edemas of the legs (20%). Average hemoglobin was 10.7 +/- 2.5 g/dl and average mean erythrocyte cell volume was 95.5 +/- 13.8 fl. There was an anemia, a leucopenia, a thrombocytopenia and a pancytopenia in respectively 27%, 18%, 15% and 8% of the cases. Average serum vitamin B(12) and homocystein levels were with 138 +/- 42 pg/ml and 22.5 +/- 15.2 micro mol/l. No patient had anti-intrinsic factor antibody and the Schilling's test was normal in all patients. Main disorders associated with FCM were atrophic gastritis (59%), long-term metformin or antiacid intake (17%), chronic alcohol intake (8%) and idiopathic FCM (n = 10). Sixteen patients have been successfully treated with oral crystalline cyanocobalamin (500 +/- 280 micro g/d).

CONCLUSIONS

This study shows that: firstly, the Cbl deficiency related to FCM may be responsible of severe neurological and hematologic manifestations in approximately 20% of the elderly patients; secondly, the disorders associated with the FCM are multiple in old age, with mainly atrophic gastritis; and thirdly, in clinical practice, oral cyanoCbl treatment may be successful.

Stem cells engineered to express self-antigen to treat autoimmunity

Autoimmune diseases are incurable. We propose a combination curative strategy using haematopoietic stem cells and gene therapy. The strategy should establish molecular chimerism with culprit antigen expressed by donor antigen-presenting cells in the thymus, resulting in immunological tolerance. Our strategy is based on the intrathymic tolerance and disease resistance established by transgenic expression of antigen in the thymus under control of an MHC class II promoter. We propose that transplantation with genetically engineered stem cells provides an advance over current autologous bone marrow transplantation, in that it should remove the significant risk of disease relapse.

19. Immunologic, gastroenterologic, and hepatobiliary disorders

A number of gastrointestinal and hepatobiliary disorders are thought to have an immunologic basis; however, the level of understanding of immunopathogenesis varies widely in these disparate conditions. For some, such as celiac disease, both important genetic and environmental determinants have been identified as well as a specific treatment. For others, such as pernicious anemia and inflammatory bowel disease, animal models have provided important research advances. Two conditions, inflammatory bowel disease and sclerosing cholangitis, are strongly associated. Characteristic immunologic features of these diseases are critical for diagnosis. Although the majority of conditions are currently treated with nonselective anti-inflammatory and immunosuppressive agents, recent research has introduced novel biological agents, exemplified by the successful use of infliximab for Crohn's disease.

Autoimmune gastropathy in type 1 diabetic patients with parietal cell antibodies: histological and clinical findings

OBJECTIVE

Approximately 15-20% of type 1 diabetic patients exhibit parietal cell antibodies (PCAs) targeting gastric H+/K+ATPase. We examined whether iron deficiency anemia, pernicious anemia, and autoimmune gastritis, which may predispose to gastric tumors, were more frequent in PCA+ than in PCA- patients.

RESEARCH DESIGN AND METHODS

Gastric biopsies from 88 consecutively recruited type 1 diabetic patients (51 men and 37 women, 47 PCA+ and 41 PCA-, aged 42 +/- 13 years) were evaluated using the updated Sydney system. Immunostaining was done for parietal cells, B- and T-cells, enterochromaffin-like (ECL) cells, and Helicobacter pylori (HP). PCAs were assayed by indirect immunofluorescence, H+/K+ATPase antibodies by enzyme immunoassay, and HP by serology, urea breath test, and histology. Pentagastrin tests were performed in 42 subjects.

RESULTS

Autoimmune gastritis (AG) was present in 57% of PCA+ and 10% of PCA- cases (OR 12.5, P < 0.0001). PCA positivity (beta = 1.44; P = 0.04) and hypergastrinemia (beta = 0.01; P = 0.026), but not HP, age, diabetes duration, sex, and HLA-DQ type were risk factors for AG. Iron deficiency anemia (OR 3.9, P = 0.015), pernicious anemia (OR = 4.6, P = 0.022), and hypochlorhydria (OR = 20.0, P = 0.0002) were more frequent in AG+ individuals. HP infection was present in 47 patients but did not influence corpus histology or gastrinemia. (Pre)malignant lesions were found in 26% of PCA+ subjects: ECL cell hyperplasia in 7 AG+ patients, comprising 1 with a gastric carcinoid tumor, and corpus intestinal metaplasia in 11 AG+ patients, including 1 with linitis plastica.

CONCLUSIONS

PCA+ type 1 diabetic patients should be screened for autoimmune gastritis, iron deficiency, and pernicious anemia. Particularly hypergastrinemic PCA+ patients with autoimmune gastritis are at increased risk for (pre)malignant gastric lesions.

Pernicious anemia during IFN-alpha treatment for chronic hepatitis C

Some latent diseases, such as immune disorders, can appear during interferon-alpha (IFN-alpha) therapy. These disorders are difficult to predict because of their low prevalence in the general population. We describe a case of pernicious anemia (PA) in a patient affected by chronic hepatitis C and macrocytosis during IFN-alpha therapy. Hemoglobin (Hb) concentration reached 7.3 g/dl. Anti-intrinsic factor (IF) antibodies were present, but not antiparietal cell antibodies (APCA). Suspension of IFN-alpha and administration of vitamin B(12) resulted in normal Hb concentrations. This case is the first instance of early PA (at the second month of IFN therapy) in a patient affected by chronic hepatitis C. The only other case of PA in a patient affected by hepatitis C virus (HCV) infection occurred during the second year of maintenance IFN therapy. We recommend that particular attention be paid to such clinical and laboratory conditions as macrocytosis in administering IFN-alpha therapy for chronic hepatitis C.

The role of esophagogastroduodenoscopy in the diagnosis and management of upper gastrointestinal disorders

Esophagogastroduodenoscopy has revolutionized the clinical management of upper gastrointestinal diseases. Millions of EGDs are performed annually in the United States for many indications, such as gastrointestinal bleeding, abdominal pain, dysphagia, or surveillance of premalignant lesions. Esophagogastroduodenoscopy is very safe, with a low risk of serious complications such as perforation, cardiopulmonary arrest, or aspiration pneumonia. It is a highly sensitive and specific diagnostic test, especially when combined with endoscopic biopsy. Esophagogastroduodenoscopy is increasingly being used therapeutically to avoid surgery. New endoscopic technology such as endosonography, endoscopic sewing, and the endoscopic videocapsule will undoubtedly extend the frontiers and increase the indications for endoscopy.

Pulmonary embolism in a patient with pernicious anemia and hyperhomocysteinemia

We report the case of a 60-year-old woman with a history of ataxia who sought evaluation after a syncopal episode. A diagnostic workup revealed pulmonary emboli, pernicious anemia (PA), hyperhomocysteinemia, and a G20210A prothrombin gene mutation. She was successfully treated with homocysteine-lowering therapy, including high doses of oral cobalamin. She also received oral anticoagulation for 6 months. At 1 year of follow-up, no further thrombotic episodes had occurred. Our report highlights the thrombotic risk of hyperhomocysteinemia secondary to PA in a patient with the G20210A prothrombin gene mutation.

Fas/CD95 is required for gastric mucosal damage in autoimmune gastritis

BACKGROUND & AIMS

Experimental autoimmune gastritis (EAG), characterized by a gastric mononuclear cell infiltrate, mucosal cell damage, and autoantibodies to parietal cell-associated H(+)/K(+) adenosine triphosphatase, is a model for human autoimmune gastritis that leads to pernicious anemia. Previous in vitro studies have implicated Fas/CD95 in initiating damage to gastric mucosal cells in humans and an animal model of autoimmune gastritis. Here we used 2 in vivo animal models to examine the role of Fas in the development of mucosal cell damage in autoimmune gastritis.

METHODS

We initiated EAG in BALB/cCrSlc mice by neonatal thymectomy and examined for Fas expression in the gastric mucosa by immunohistochemistry. To address the in vivo relevance of Fas in mucosal injury, we examined the stomachs and sera of BALB/cCrSlc lpr/lpr mice subjected to neonatal thymectomy and BALB/cCrSlc nu/nu lpr/lpr mice transferred with lymphocytes from gastritic BALB/cCrSlc mice.

RESULTS

Fas expression was up-reguiated in parietal cells of mice with EAG. Neonatally thymectomized lpr/lpr mice were resistant to developing destructive gastritis compared with heterozygous and wild-type littermates. Nu/nu Fas-sufficient mice transferred with lymphocytes from thymectomized lpr/lpr mice developed destructive gastritis. Nu/nu lpr/lpr mice transferred with lymphocytes from gastritic mice developed a nondestructive gastritis.

CONCLUSIONS

The observations that Fas is up-regulated in gastric parietal cells of mice with EAG and that Fas-deficient mice are resistant to development of destructive gastritis provide compelling evidence that Fas is required in vivo for development of gastric mucosal cell damage in autoimmune gastritis.

Endogenous H/K ATPase beta-subunit promotes T cell tolerance to the immunodominant gastritogenic determinant

A CD4(+) T cell response to the gastric H/K ATPase beta-subunit (H/Kbeta) is required for the onset of experimental autoimmune gastritis in BALB/c mice. The extent to which endogenous H/Kbeta contributes toward the tolerance of the H/Kbeta-specific T cell repertoire in normal individuals is not known. By comparison of T cell responses in H/Kbeta-deficient (o/o) and H/Kbeta-expressing BALB/c mice, in this work we show that the endogenous H/Kbeta autoantigen plays a major role in the tolerance of pathogenic H/Kbeta-specific T cells. First, T cell-dependent Ab responses to the H/Kbeta Ag were enhanced in H/K ATPase-immunized H/Kbeta-deficient mice compared with wild-type mice. Second, peptide immunization experiments indicated that immune responses to the major gastritogenic epitope of the H/K ATPase, namely H/Kbeta(253-277), were significantly more vigorous in H/Kbeta-deficient mice compared with wild-type mice. Third, unfractionated splenocytes from H/Kbeta-deficient mice, but not H/Kbeta-expressing mice, induced autoimmune gastritis after adoptive transfer to BALB/c nude mice. The enhanced responses to H/Kbeta in H/Kbeta-deficient mice were shown to be intrinsic to CD4(+)CD25(-) T cells rather than a change in status of CD4(+)CD25(+) regulatory T cells. We conclude from these studies that the H/Kbeta-specific T cells in wild-type mice represent the residue of a T cell repertoire, directed toward a single determinant, that has been subjected to partial tolerance induction.

Characterisation of proton pump antibodies and stomach pathology in gastritis induced by neonatal immunisation without adjuvant

It has previously been reported that neonatal BALB.D2 mice injected with native proton pump antigens without adjuvant develop an irreversible gastritis (Claeys et al, 1997). The ease of inititating gastritis in the neonate stands in contrast with the difficulty in initiating gastritis in adult mice that require repeated immunisation in adjuvant that is reversible following cessation of immunisation (Scarff et al, 1997). In view of these contrasting observations, we set out to ascertain whether we could confirm the observations in neonatal mice as well as further characterise the pathology and the autoantibody response. We found that neonatal gastritis-susceptible BALB/c mice (n=12), immunised with either pig or mouse gastric membranes in the absence of adjuvant, develop gastritis without circulating antibody to parietal cells detected by immunofluorescence, a hallmark of murine and human gastritis (Toh et al, 1997). However, mice immunized with pig gastric membranes (n=6) had circulating antibodies reactive by immunofluorescence to recombinant alpha and/or beta subunit of gastric H+/K+-ATPase expressed by insect cells (Sfalpha and Sfbeta). Four mice from this cohort with antibodies to Sfbeta also had reactivity to gastric H+/K+-ATPase by ELISA, and 3 immunoblotted the beta but not the alpha subunit of the ATPase. In the cohort of mice immunised with mouse gastric membranes (n=6), four produced antibodies reactive by immunofluorescence to Sfalpha, two of which were also reactive to Sfbeta and one developed antibodies detected by ELISA to gastric H+/K+-ATPase. However, no members of this cohort had antibodies reactive by immunoblotting to either the beta or alpha subunit of the ATPase. In all cases gastritic stomachs were characterised by areas deficient in ribosome-rich zymogenic cells and marked reductions in H+/K+-ATPase-positive parietal cells. Metaplasia detected by Maxwell stain, as clusters of mucus-producing cells throughout gastric units, were non-reactive to stomach mucin autoantibody suggesting the mucins comprise other and/or aberrant form(s). Compared to our previous observations in adult mice, our present data confirms that gastric autoimmunity is more readily induced in the neonate than the adult. Our data also affirms that while the neonatal immune system can mount a damaging inflammatory cellular immune response to gastric antigens, it develops an altered antibody response.

Treatment of vitamin b(12)-deficiency anemia: oral versus parenteral therapy

OBJECTIVE

To evaluate the use of oral cyanocobalamin therapy in the treatment of cobalamin (vitamin B(12))-deficient anemia.

DATA SOURCES

Primary and review articles were identified by MEDLINE search (1966-May 2000) and through secondary sources.

DATA SYNTHESIS

Cobalamin-deficient anemia is among the most common diagnoses in older populations. Cobalamin-deficient anemia may be diagnosed as pernicious anemia, resulting from the lack of intrinsic factor required for cobalamin absorption or as protein malabsorption from the inability to displace cobalamin from protein food sources. Several studies provide evidence that daily oral cyanocobalamin as opposed to monthly parenteral formulations may adequately treat both types of cobalamin-deficient anemias.

CONCLUSIONS

Daily oral cyanocobalamin at doses of 1000-2000 microg can be used for treatment in most cobalamin-deficient patients who can tolerate oral supplementation. There are inadequate data at the present time to support the use of oral cyanocobalamin replacement in patients with severe neurologic involvement.

APS-I/APECED: the clinical disease and therapy

The clinical picture and course of APS-I or APD-I/APECED is widely variable: the list of possible disease components includes some 30 disorders. The initial manifestation may not include any of the known characteristic components, namely, mucocutaneous candidiasis, hypoparathyroidism, or adrenocortical insufficiency. Although mutation detection is available, it does not help to exclude this disease. Diagnostic strategy needs to be based on knowledge of the clinical picture, including the features of ectodermal dystrophy.

Modern approaches to the investigation of vitamin B12 deficiency

The classic workup of a patient for possible PA is revisited in light of the vanishing Schilling test. The vagaries of testing for B12 and blocking antibodies are reexamined. The advantages and disadvantages of newer tests such as MMA and serum gastrin levels are catalogued. At this juncture in the evolution of new test strategies, there is a considerable controversy regarding the significance of high MMA levels in the face of normal B12 levels, particularly in the elderly. Hopefully, this controversy will soon be resolved and the newer crop of tests will be proven and accepted in the workplace. Still, the words of Alexander Pope spring to mind: "Be not the first by whom the new are tried, Nor yet the last to lay the old aside."

Multifocal atrophic gastritis and gastric carcinoma

Gastric carcinoma remains a major cause of morbidity and mortality worldwide despite its significant decline in recent years. H. pylori infection begins with nonatrophic gastritis, and most individuals continue to have nonatrophic H. pylori gastritis throughout their lifetime. A minority of those with severe antral inflammation will develop a duodenal ulcer, and a few, for unknown reasons, may develop gastric MALT lymphoma. Others, who acquired the H. pylori infection in early childhood, develop progressive multifocal atrophic gastritis with loss of gastric glands. A small proportion of these individuals develop extensive, incomplete (type III) intestinal metaplasia, and an even smaller proportion will progress to dysplasia and intestinal-type gastric carcinoma. H. pylori-associated gastritis is also a risk factor for diffuse-type gastric carcinoma, which is not preceded by atrophy, intestinal metaplasia, or dysplasia. Appropriate screening and preventive measures should be considered in high-risk groups. It is also crucial to identify cofactors such as genetic susceptibility and environmental factors that might interact with H. pylori infection to increase gastric cancer risk. To make an impact on gastric cancer incidence and mortality, serious consideration should be given to early H. pylori eradication in high-risk groups and endoscopic surveillance according to the updated Sydney system in some patients with high-risk preneoplastic lesions, whereas dysplastic lesions should be removed without delay. Studies currently in progress may tell us whether H. pylori eradication can prevent later development of gastric carcinoma and thus eliminate a major cause of mortality worldwide.

Autoantibodies in autoimmune polyendocrine syndrome type II

The autoimmune polyendocrine syndrome type II (APS-II) is characterized by the association of autoimmune Addison's disease with thyroid autoimmune diseases or type-1 diabetes mellitus. 21-Hydroxylase autoantibodies enable the accurate diagnosis of autoimmune Addison's disease and, in patients with other endocrine autoimmune diseases, identify subjects at high risk for clinical adrenal insufficiency. 17 alpha-Hydroxylase (17OH) and side-chain-cleavage enzyme (P450scc) are target autoantigens of steroid-cell autoantibodies, and in women with Addison's disease, 17OH autoantibodies and P450scc autoantibodies are markers of increased risk for premature ovarian failure. Thyroperoxidase autoantibodies, thyroglobulin autoantibodies, H+/K(+)-ATPase autoantibodies, and GAD65 autoantibodies are frequently detected in patients with isolated Addison's or APS-II. Screening for other organ-specific autoimmune diseases should be performed in every patient with at least one major disease component of APS-II.

Serum pepsinogen and gastrin levels in HIV-positive patients: relationship with CD4+ cell count and Helicobacter pylori infection

BACKGROUND

The relationship between serum parameters of gastric function and Helicobacter pylori infection in human immunodeficiency virus (HIV)-positive patients is almost unknown.

AIMS

To investigate in HIV-infected patients: (i) the relationship between serum gastrin and serum pepsinogens over the progressive phases of HIV-related disease; (ii) the impact of H. pylori infection on gastrin and pepsinogen serum levels and its relation to antral histology; (iii) the prevalence of parietal cell autoantibodies.

METHODS

Fifty-nine HIV-positive patients were studied by upper endoscopy plus gastric antral biopsy. Serum samples were tested for gastrin, pepsinogen A, pepsinogen C and parietal cell autoantibodies.

RESULTS

In patients without overt acquired immunodeficiency syndrome (AIDS), or with a CD4+ count of > 100 x 10(6) cells/L, mean serum levels of gastrin and pepsinogen C were higher than in subjects with AIDS or with a CD4+ count of < 100 x 10(6) cells/L (P < 0.01). Only one patient was found to be positive for parietal cell autoantibodies. H. pylori infection was associated with increased values of gastrin and pepsinogen C only in HIV-positive patients without AIDS or with a CD4+ count of > 100 x 10(6) cells/L. Atrophy was more frequent in patients with overt AIDS than in those without overt AIDS (57% vs. 33%, P=N.S.), and/or in patients with a CD4+ count of < 100 x 10(6) cells/L than in those with a CD4+ count of > 100 x 10(6) cells/L (62% vs. 26%, P < 0.05).

CONCLUSIONS

HIV-positive patients without overt AIDS have increased serum levels of gastrin and pepsinogen C compared with HIV-positive patients with overt AIDS.

[Myelopathy due to vitamin B12 deficiency presenting as transverse myelitis]

Vitamin B12 deficiency may induce neuropathy, myelopathy, dementia and optic neuropathy. The diagnosis is established by vitamin B12, homocysteine and methylmalonic acid measurements. Myelin and axon destruction in the white matter of the spinal cord are observed. The posterior column of the cervical and thoracic level is the most common involved area. The involvement of the anterior column is restricted to advanced and relatively severe cases. Treatment is based on vitamin B12 injections, and the prognosis depends on the stage of vitamin deficiency and deterioration at treatment onset. We report a case with transverse myelitis due to vitamin B12 deficiency. This picture is relatively uncommon, however, we believe patients with transverse myelitis should have vitamin B12 studies as part of the diagnosis work up.

[Combined sclerosis of the spinal cord revealing vitamin B 12 deficiency: geriatric characteristics apropos of a case evaluated by MRI]

INTRODUCTION

Cobalamin deficiency is common in the elderly. However, most of the patients are asymptomatic or present with few symptoms. A subacute combined degeneration of the spinal cord accounts for only 10% of the neurological complications. Revealing forms of this myelopathy are exceptional, and were rarely documented by magnetic resonance imaging (MRI) study.

EXEGESIS

We report a case of subacute combined degeneration of spinal cord in an 81-year-old woman evaluated by a spinal cord MRI. We discuss the role of the spinal cord radiographic study in the diagnosis, the etiopathogeny of cobalamin deficiency and the benefit of vitamin supplementation even at a late stage of the disease in geriatrics patients.

CONCLUSION

The spinal cord MRI is useful in the diagnosis of late-form combined spinal cord degeneration. The high frequency of atrophic gastritis in elderly prevents the identification of a deficiency of the cobalamin etiology. The treatment relies on vitamin therapy even in the late stages. The severe disability of cobalamin deficiency neurological complications must encourage an earlier diagnosis in elderly patients.

Neurologic manifestations of hematologic disorders

The subject of hematologic disease is vast, including disorders of cellular component excesses, deficiencies or destruction, and dysfunction. Many of these disorders may lead to neurologic complication. Some of these neurologic conditions are very specific to the hematologic disorder (such as the subacute combined deficiency seen in vitamin B12 deficiency anemia) while others are common to several conditions (hyperviscosity syndrome seen with macroglobulinemia and leukemias). This article reviews some of the more common hematologic diseases and their accompanying neurologic conditions.

Helicobacter pylori, parietal cell antibodies and autoimmune gastropathy in type 1 diabetes mellitus

BACKGROUND

Fifteen to 20% of type 1 diabetic patients exhibit parietal cell antibodies (PCA), which are associated with autoimmune gastritis, hypochlorhydria, iron deficiency and pernicious anaemia.

AIM

To examine whether Helicobacter pylori infection could explain the high prevalence of PCA and autoimmune gastropathy in diabetes. If so, H. pylori eradication could prevent autoimmune gastritis.

METHODS

In 229 type 1 diabetics (M/F: 135/94; age: 41 +/- 12 years) PCA were measured. H. pylori infection was assessed by serology, urea breath test in all and by histology (updated Sydney system) in 88 subjects. Pentagastrin tests were performed in 42 patients.

RESULTS

Sixty-nine patients were PCA-positive. H. pylori infection was present in 72 patients and was negatively associated with HLA-DQA1*0103-B1*0603 (OR=0.12, P=0.015) and positively with DQA1*0501-B1*0201 (OR=1.9, P=0.032). PCA-positivity was linked to HLA-DQA1*0501-B1*0301 (OR=3.9, P=0.017). A link between H. pylori and PCA was observed when PCA-positivity was defined as a titre > or = 1/20 (OR=2.0, P=0.03), but not if > or =1/40 was the cut-off point. PCA-positivity, but not H. pylori infection, was associated with iron deficiency anaemia (OR=2.7, P=0.008), pernicious anaemia (OR= 33.5, P < 0.0001), hypochlorhydria (OR=12.1, P=0.0008) and autoimmune gastritis (OR=12.5, P < 0.0001).

CONCLUSIONS

The HLA-bound susceptibility of H. pylori and PCA differed. PCA-positivity but not ongoing H. pylori infection is associated with autoimmune gastritis. Low titres of PCA might reflect H. pylori infection rather than autoimmune gastropathy.

Stimulation of CD25(+)CD4(+) regulatory T cells through GITR breaks immunological self-tolerance

CD25(+)CD4(+) regulatory T cells in normal animals are engaged in the maintenance of immunological self-tolerance. We show here that glucocorticoid-induced tumor necrosis factor receptor family-related gene (GITR, also known as TNFRSF18)--a member of the tumor necrosis factor-nerve growth factor (TNF-NGF) receptor gene superfamily--is predominantly expressed on CD25(+)CD4(+) T cells and on CD25(+)CD4(+)CD8(-) thymocytes in normal naïve mice. We found that stimulation of GITR abrogated CD25(+)CD4(+) T cell-mediated suppression. In addition, removal of GITR-expressing T cells or administration of a monoclonal antibody to GITR produced organ-specific autoimmune disease in otherwise normal mice. Thus, GITR plays a key role in dominant immunological self-tolerance maintained by CD25(+)CD4(+) regulatory T cells and could be a suitable molecular target for preventing or treating autoimmune disease.

Animal models of human disease: experimental autoimmune gastritis--a model for autoimmune gastritis and pernicious anemia

Human autoimmune gastritis is an organ-specific autoimmune disease of the stomach. It is characterized by the development of disease-specific autoantibodies and a pathology that specifically targets specialized cells within the gastric environment. The autoantigens associated with this disease have been defined as the gastric H+/K+ ATPase and intrinsic factor. The development of experimental disease models has been pivotal in our contemporary understanding of autoimmunity. Here we review mouse models of autoimmune gastritis and their relevance to human autoimmune gastritis associated with pernicious anemia. We appraise some historical as well as recent studies of experimental autoimmune gastritis (EAG), highlighting key findings that have formed the basis of our current understanding of the etiology and mechanism(s) associated with autoimmune gastritis. A precise understanding of the pathogenesis of autoimmune gastritis will permit the design of innovative and rational therapeutic strategies to prevent, arrest, ameliorate or reverse the disease.

Requirements for autoimmune responses to mouse gastric autoantigens

Autoimmune gastritis, in which the H+/K(+)-ATPase of parietal cells is the major antigen, is one of the most common autoimmune diseases. Here we examined if specific properties of the H+/K(+)-ATPase or parietal cells are involved in rendering them autoimmune targets. The model antigens beta-galactosidase and ovalbumin (OVA) were expressed in parietal cells of transgenic mice. On experimental induction of autoimmune gastritis by neonatal thymectomy, autoantibodies to beta-galactosidase developed in mice expressing beta-galactosidase in parietal cells, a response that was independent of either the response to the gastric H+/K(+)-ATPase or gastric inflammation. In contrast, mice that expressed OVA in parietal cells did not exhibit an antibody response to OVA after thymectomy. However, increasing the frequency of anti-OVA T lymphocytes in OVA-expressing mice resulted in autoantibodies to OVA and gastritis. These studies indicate that parietal cells can present a variety of antigens to the immune system. Factors such as the identity and expression level of the autoantigen and the frequency of autoreactive T cells play a role in determining the prevalence and outcome of the particular immune response. In addition, as not all mice of a particular genotype displayed autoimmunity, random events are involved in determining the target of autoimmune recognition.

Beta-cell, thyroid, gastric, adrenal and coeliac autoimmunity and HLA-DQ types in type 1 diabetes

The autoimmune attack in type 1 diabetes is not only targeted to beta cells. We assessed the prevalence of thyroid peroxidase (aTPO), parietal cell (PCA), antiadrenal (AAA) and endomysial antibodies (EmA-IgA), and of overt autoimmune disease in type 1 diabetes, in relation to gender, age, duration of disease, age at onset, beta-cell antibody status (ICA, GADA, IA2A) and HLA-DQ type. Sera from 399 type 1 diabetic patients (M/F: 188/211; mean age: 26 +/- 16 years; duration: 9 +/- 8 years) were tested for ICA, PCA, AAA and EmA-IgA by indirect immunofluorescence, and for IA2A (tyrosine phosphatase antibodies), GADA (glutamic acid decarboxylase-65 antibodies) and aTPO by radiobinding assays. The prevalence rates were: GADA 70%; IA2A, 44%; ICA, 39%; aTPO, 22%; PCA, 18%; EmA-IgA, 2%; and AAA, 1%. aTPO status was determined by female gender (beta = - 1.15, P = 0.002), age (beta = 0.02, P = 0.01) and GADA + (beta = 1.06, P = 0.02), but not by HLA-DQ type or IA2A status. Dysthyroidism (P < 0.0001) was more frequent in aTPO + subjects. PCA status was determined by age (beta = 0.03, P = 0.002). We also observed an association between PCA + and GADA + (OR = 1.9, P = 0.049), aTPO + (OR = 1.9, P = 0.04) and HLA DQA1*0501-DQB1*0301 status (OR = 2.4, P = 0.045). Iron deficiency anaemia (OR = 3.0, P = 0.003) and pernicious anaemia (OR = 40, P < 0.0001) were more frequent in PCA + subjects. EmA-IgA + was linked to HLA DQA1*0501-DQB1*0201 + (OR = 7.5, P = 0.039), and coeliac disease was found in three patients. No patient had Addison's disease. In conclusion, GADA but not IA2A indicate the presence of thyrogastric autoimmunity in type 1 diabetes. aTPO have a female preponderance, PCA are weakly associated with HLA DQA1*0501-DQB1*0301 and EmA-IgA + with HLA DQA1*0501-DQB1*0201.

Delirium

BACKGROUND

Delirium is a serious and often undetected neuropsychiatric syndrome. Failure to recognize and manage delirium can lead to longer hospital stays and increased morbidity and mortality, especially among the elderly.

REVIEW SUMMARY

This article reviews definitions and diagnosis. The Diagnostic and Statistical Manual of Mental Disorders, 4th edition, and the International Statistical Classification of Diseases and Related Health Problems, 10th edition, criteria are quite similar in their diagnostic criteria. Risk factors include advanced age, preexisting brain disease or cognitive impairment, multiple medications, and severe medical problems. Delirium in the elderly can be more subtle and recovery more prolonged. Diagnosis is more complex if there is already an underlying dementia. An organized approach should be used to discover etiology and in ordering appropriate laboratory studies. At the cellular level, delirium is considered to be a reversible disregulation of neuronal membrane function. This involves a selective vulnerability of certain populations of neurons and neurotransmitter dysfunction. Practical treatment issues are reviewed.

CONCLUSIONS

Despite advances, delirium is usually still diagnosed at the bedside. Having an organized approach to diagnosis and understanding the underlying pathophysiology should help with overall evaluation and treatment.

SET-related cell division autoantigen-1 (CDA1) arrests cell growth

We used an autoimmune serum from a patient with discoid lupus erythematosus to clone a cDNA of 2808 base pairs. Its open reading frame of 2079 base pairs encodes a predicted polypeptide of 693 amino acids named CDA1 (cell division autoantigen-1). CDA1 has a predicted molecular mass of 79,430 Daltons and a pI of 4.26. The size of the cDNA is consistent with its estimated mRNA size. CDA1 comprises an N-terminal proline-rich domain, a central basic domain, and a C-terminal bipartite acidic domain. It has four putative nuclear localization signals and potential sites for phosphorylation by cAMP and cGMP-dependent kinases, protein kinase C, thymidine kinase, casein kinase II, and cyclin-dependent kinases (CDKs). CDA1 is phosphorylated in HeLa cells and by cyclin D1/CDK4, cyclin A/CDK2, and cyclin B/CDK1 in vitro. Its basic and acidic domains contain regions homologous to almost the entire human leukemia-associated SET protein. The same basic region is also homologous to nucleosome assembly proteins, testis TSPY protein, and an uncharacterized brain protein. CDA1 is present in the nuclear fraction of HeLa cells and localizes to the nucleus and nucleolus in HeLa cells transfected with CDA1 or its N terminus containing all four nuclear localization signals. Its acidic C terminus localizes mainly to the cytoplasm. CDA1 levels are low in serum-starved cells, increasing dramatically with serum stimulation. Expression of the CDA1 transgene, but not its N terminus, arrests HeLa cell growth, colony numbers, cell density, and bromodeoxyuridine uptake in a dose-dependent manner. The ability of CDA1 to arrest cell growth is abolished by mutation of the two CDK consensus phosphorylation sites. We propose that CDA1 is a negative regulator of cell growth and that its activity is regulated by its expression level and phosphorylation.