Intrinsic-factor antibodies in absence of pernicious anaemia. 3-7 year follow-up

Update on Serum Biomarkers in Autoimmune Atrophic Gastritis

BACKGROUND

Autoimmune atrophic gastritis (AAG) is a persistent, corpus-restricted immune-mediated destruction of the gastric corpus oxyntic mucosa with reduced gastric acid and intrinsic factor secretion, leading to iron deficiency and pernicious anemia as a consequence of iron and cobalamin malabsorption. Positivity toward parietal cell (PCA) and intrinsic factor (IFA) autoantibodies is very common. AAG may remain asymptomatic for many years, thus making its diagnosis complex and often delayed. Due to the increased risk of gastric neoplasms, a timely diagnosis of AAG is clinically important.

CONTENT

The gold standard for AAG diagnosis is histopathological assessment of gastric biopsies obtained during gastroscopy, but noninvasive, preendoscopic serological screening may be useful in some clinical scenarios. Serum biomarkers for AAG may be divided into 2 groups: gastric autoimmunity-related biomarkers, such as PCA and IFA, and gastric corpus atrophy/reduced gastric acid secretion-related biomarkers, such as serum gastrin and pepsinogens. The present review focuses on the clinical significance and pitfalls of serum biomarkers related to gastric autoimmunity and gastric corpus atrophy, including some discussion of analytical methods.

SUMMARY

Serum assays for PCA, IFA, gastrin, and pepsinogen I show good diagnostic accuracy for noninvasive diagnostic work-up of AAG. Diagnostic performance may increase by combining >1 of these tests, overcoming the problem of seronegative AAG. However, appropriately designed, comparative studies with well-characterized patient cohorts are needed to better define the reliability of these biomarkers in the diagnosis of patients with AAG. Currently, positive serum tests should always be followed by the state-of-art diagnostic test, that is, histopathological assessment of gastric biopsies obtained during gastroscopy to definitively confirm or rule out AAG and eventually neoplastic complications.

Intrinsic factor autoantibodies by luminescent immuno-precipitation system in patients with corpus atrophic gastritis

Background

Corpus atrophic gastritis (CAG) may lead to intrinsic factor (IF) deficiency and vitamin B₁₂ malabsorption. Intrinsic factor autoantibodies (IFA) are considered markers of pernicious anemia, but their clinical utility in CAG has not been evaluated. This study aimed to assess IFA in CAG patients and controls using a luciferase immunoprecipitation system (LIPS).

Methods

Recombinant nanoluciferase-tagged IF secreted from transfected Expi293F cells was used as antigen in an IFA-LIPS assay. IFA IgG were measured in sera from subjects undergoing gastroscopy and biopsy (updated Sydney system) mainly for anemia (57%) or dyspepsia (34%). This cohort comprised 105 patients with histologically-proven-CAG (cases: median age 64 years, 68% females) and 110 subjects with suspected CAG that were histologically negative (controls: median age 67 years, 54% females). Cut-off values were selected by Q-Q-plot analysis (negative: <2.5 arbitrary units).

Results

IFA levels were higher in cases than in controls (Mann-Whitney:p < 10⁻⁵). The ROC-AUC was 0.67 (95%CI 0.60–0.73, p < 0.0001). The IFA LIPS sensitivity and specificity for CAG were 32% (95% CI 24–42) and 95% (95% CI 90–99). This diagnostic performance remained similar after stratification for the presence/absence of anemia, dyspepsia or vitamin B₁₂ deficiency. IFA levels were higher in females compared with males (p = 0.0127). In females aged <65 years, IFA-positives were more prevalent than in males (43.5% vs 6.6%, p = 0.011).

Conclusions

The IFA-LIPS assay discriminated between CAG patients and controls showing a good specificity (95%) at the cost of sensitivity (32%). IFA-positivity occurred independently from anemia and vitamin B₁₂ deficiency, but was more frequent in younger females. IFA testing should be considered in patients at high clinical suspicion of CAG.

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A novel diagnostic autoantibody test for intrinsic factor autoantibodies using a LIPS in histologically-proven CAG patients and controls.

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This assay discriminated between patients and controls with a good specificity and a relatively low sensitivity that reflects the likely low prevalence of intrinsic factor antibodies in CAG.

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Positivity occurred independently from anemia and vitamin B₁₂ deficiency.

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Intrinsic factor antibodies should be assessed in patients at high clinical suspicion of CAG.

Autoimmune mechanisms in pernicious anaemia & thyroid disease

Pernicious anaemia (PA) and some types of thyroid disease result from autoimmune processes. The autoimmune mechanisms in these conditions have not been fully elucidated. This review discusses the autoimmune mechanisms involved in PA and how these affect diagnosis and disease progression. In addition to gastric antibodies, antibodies to the vitamin B12 binding protein transcobalamin which can result in high serum B12 levels are also addressed with regard to how they affect clinical practice. The role of autoimmune susceptibility is investigated by comparing PA to one of its most common comorbidities, autoimmune thyroid disease (AITD). Thyroid disease (although not exclusively AITD) and B12 deficiency are both also implicated in the pathology of hyperhomocysteinemia, an elevated homocysteine in plasma. Since hyperhomocysteinemia is a risk factor for cardiovascular occlusive disease, this review also addresses how thyroid disease in particular leads to changes in homocysteine levels.

Murine experimental autoimmune gastritis models refractive to development of intrinsic factor autoantibodies, cobalamin deficiency and pernicious anemia

Researchers have developed murine lymphopenic, non-lymphopenic, transgenic, spontaneous and infectious agent based models to induce an experimental autoimmune gastritis (EAG) for the study of human organ-specific autoimmune disease. These models result in a chronic inflammatory mononuclear cell infiltrate in the gastric mucosa, destruction of parietal and zymogenic cells with autoantibodies reactive to the gastric parietal cells and the gastric H+/K+ ATPase (ATP4), arguably hallmarks of a human autoimmune gastritis (AIG). In the case of AIG, it is well documented that, in addition to parietal cell antibodies being detected in up to 90% of patients, up to 70% have intrinsic factor antibodies with the later antibodies considered highly specific to patients with pernicious anemia. This is the first report specifically investigating the occurrence of intrinsic factor antibodies, cobalamin deficiency and pernicious anemia in EAG models. We conclude, in contrast to AIG, that, in the three EAG models examined, intrinsic factor is not selected as a critical autoantigen.

Lack of specific association between gastric autoimmunity hallmarks and clinical presentations of atrophic body gastritis

AIM: To investigate the possible relationships between gastric autoimmune phenomena and clinical presentations of this disorder, in consecutive atrophic body gastritis patients.

METHODS: A total of 140 atrophic body gastritis patients, diagnosed as consecutive outpatients presenting with macrocytic or iron deficiency anemia, or longstanding dyspepsia underwent gastroscopy with antral and body biopsies, assay of intrinsic factor, parietal cells and Helicobacter pylori (H pylori) antibodies. Gastritis was assessed according to Sydney System.

RESULTS: Parietal cell antibodies were equally distributed in all clinical presentations, whereas the positivity of intrinsic factor antibodies (49/140, 35%) was significantly higher in pernicious anemia patients (49.2%) than in iron deficiency (21.1%) and dyspeptic patients (27.8%). No specific pattern of autoantibodies was related to the clinical presentations of atrophic body gastritis. A positive correlation was obtained between the body atrophy score and the intrinsic factor antibody levels (r = 0.2216, P = 0.0085). Associated autoimmune diseases were present in 25/140 (17.9%) patients, but the prevalence of autoimmune diseases was comparable, irrespective of the clinical presentations.

CONCLUSION: The so-called hallmarks of gastric autoimmunity, particularly in intrinsic factor antibody cannot be usefully employed in defining an autoimmune pattern in the clinical presentations of ABG.

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."

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.

Pathophysiological effects of long-term acid suppression in man

A critical evaluation has been made of the available evidence in man of the effects of prolonged low acid states on the structure and function of the stomach. Various human models have been examined. 1. Ageing does not affect acid output from the normal male stomach, and there may be an increase in women. With progressive atrophy of the corpus mucosa, which is more frequent and rapid in patients with gastric ulcer, there is an associated loss of secretory function. Chronic gastritis and atrophy are the most important age-related changes, which in many cultures are hypothesized to develop via a prior Helicobacter pylori-related gastritis. However, H. pylori colonization of the mucosa decreases with increasing grades of gastric atrophy probably because intestinal metaplasia provides a hostile environment. Atrophy and intestinal metaplasia are associated with precancerous lesions and gastric cancer. Apparent hyperplasia of the gastric argyrophil endocrine cells is a common and spontaneous phenomenon in patients with atrophic gastritis, which in part may be related to the preferential loss of nonendocrine cells. 2. Pernicious anemia is associated with a complete lack of acid production, marked hypergastrinemia, and endocrine cell hyperplasia in the majority of patients. ECL-cell carcinoids and gastric cancer occur with a prevalence of 3-7%, and endoscopic surveillance in routine clinical practice is not warranted. 3. Gastric ECL-cell carcinoids are rare events that have been described in association with two diseases in man, pernicious anemia and Zollinger-Ellison syndrome as part of multiple endocrine neoplasia syndrome type I, and usually relate to marked hypergastrinemia and the presence of chronic atrophic gastritis with gastric antibodies or a genetic defect rather than the presence or absence of acid. Regression or disappearance of ECL-cell carcinoids, either spontaneously or after removal of the gastrin drive, has been recorded. Lymph node, and rarely hepatic, metastases are documented but death in these cases has been anecdotal. 4. Therapy with H2 antagonists may result in up to a twofold rise in serum gastrin levels but in man no endocrine cell hyperplasia has been recorded. However, the data for H2 antagonists on these aspects are very limited. There is no drug-related risk of gastric or esophageal cancer, although the incidence of the latter may be raised. Long-term treatment with omeprazole is associated with a two- to fourfold increase in gastrin levels over baseline values in one third of patients and apparent endocrine cell hyperplasia in 7% of cases overall.(ABSTRACT TRUNCATED AT 400 WORDS)

Pernicious anemia revisited

OBJECTIVE

We discuss the pathophysiologic mechanisms, clinical features, diagnosis, and treatment of pernicious anemia (PA).

DESIGN

A review of the clinical applications of the diagnostic and therapeutic progress of PA is presented.

MATERIAL AND METHODS

A patient with PA may have a wide range of initial complaints that affect various organ systems or may be entirely asymptomatic. Hematologic variables may be normal in patients with cobalamin (Cbl) deficiency. Because of the difficulties in diagnosing Cbl deficiency, alternatives to measuring Cbl have been sought. Determining the urinary methylmalonic acid level is a less invasive, more practical, and, possibly, more sensitive method. The Schilling test is performed for assessment of the absorption of orally ingested radiolabeled crystalline cyano-Cbl; results should be interpreted cautiously.

RESULTS

Vitamin B12 therapy should be lifelong. It is customarily administered intramuscularly. Other routes of administration have been studied.

CONCLUSION

PA is one of the most treatable hematologic disorders.

Anti-intrinsic factor antibodies in systemic lupus erythematosus

As the co-existence of pernicious anaemia (PA) and systemic lupus erythematosus (SLE) has been repeatedly reported, we have investigated the presence of anti-intrinsic factor antibodies (IFAb), the immunological hallmark of PA, in patients diagnosed with SLE. Serum cobalamin levels and IFAb were determined in 30 women diagnosed with SLE as well as in 45 controls. Cobalamin levels were low in 7/30 patients. IFAb were detected in 3/30 sera from patients but in none of the control sera. The presence of IFAb was associated with a low cobalamin concentration, anaemia and macrocytosis in only one patient. There was no evident relationship between the presence of IFAb and serological markers of SLE. We conclude that IFAb may appear in SLE patients, although the cobalamin deficiency described in SLE seems to be due to the presence of IFAb in only a minority of cases.

Longitudinal study of circulating gastric antibodies in pernicious anaemia

Temporal changes in gastric antibody response were investigated in 113 (51 men, 62 women) patients with confirmed pernicious anaemia. Their ages ranged from 31-92 years (mean (SD 13.2) 66). At diagnosis, parietal cell antibody and intrinsic factor antibody were detected in 90.9% and 39.1% of all patients, respectively. When the tests were repeated after a mean follow up of 70 months (range 14-137), parietal cell antibody and intrinsic factor antibody were positive in 82.8% and 58.7%, respectively. There was a definite but not significant trend for the organ specific parietal cell antibody to disappear; intrinsic factor antibody became more positive. These results may indicate that with progressive parietal cell destruction, the antigen is no longer available to sustain an immunological response. On the other hand, this hypothesis does not explain the increased prevalence of intrinsic factor antibody which is also a product of parietal cells.

How to diagnose (and not misdiagnose) pernicious anaemia

The diagnosis of pernicious anaemia requires the demonstration that megaloblastic haemopoiesis is present, that vitamin B12 deficiency is present and that gastric intrinsic factor is lacking. The first, generally requires marrow aspiration, the second is satisfied by a low serum B12 level and the third by B12 absorption tests with and without intrinsic factor. The reasons why these three criteria are the minimum criteria for diagnosis are discussed as well as pitfalls in the performance of tests and in interpretation of data. Finally, a low serum vitamin B12 with impaired B12 absorption improved by the addition of intrinsic factor in the absence of blood changes indicates severe atrophic gastritis but not pernicious anaemia.

Megaloblastic anaemia, cobalamin, and folate

Developments relating to cobalamin and folate are reviewed. Current work on the relations between these two coenzymes are discussed, particularly those that have emerged in studies using nitrous oxide, which inactivates cobalamin.

Immunological aspects of gastritis and pernicious anaemia

Pernicious anaemia (PA) and chronic atrophic gastritis (CAG) aggregate in families, occur more often in women, and are associated with various heritable traits such as fair skin and blue eyes. They are linked to certain HLA types. Linkages are relatively weak for A and B antigens, but somewhat stronger in the case of DR antigens. There are strong associations between PA and other organ-specific autoimmune diseases, particularly those affecting the thyroid. Discordance for PA in monozygotic twins has been reported, and it may well be that expression of the disease requires, in a genetically susceptible individual, initial injury to the gastric mucosa by some environmental agent such as a virus or some physical irritant, with perpetuation of injury then depending upon autoimmune mechanisms. Numbers of T cells are substantially increased in the gastric mucosa of patients with PA, but the ratio of T suppressor to T helper cells is normal. There is a relatively greater increase in numbers of cells not of T lineage, presumably B-cells. Gastric autoantibodies, both to different components of the parietal cell and to two sites on the IF molecule, are present in a majority of patients with PA. There is evidence that these autoantibodies, especially PCA, may be cytotoxic to parietal cells, and may also inhibit their maturation and proliferation. Antibodies to chief cells have not been described, and the parallel disappearance of these cells in atrophic gastritis is unexplained. The peripheral blood lymphocytes of some patients with autoimmune gastritis transform, or produce lymphokines, when exposed to gastric antigens, and patients with PA have been shown to have delayed type cutaneous hypersensitivity to gastric antigens. The relevance of these observations to the pathogenesis of their gastric mucosal lesion is unclear. There is a growing body of evidence to support the operation of humoral immune mechanisms in autoimmune gastritis, but this clearly does not preclude the coexistent involvement of cellular mechanisms. For example, impaired suppressor T cell function has been strongly implicated in certain other autoimmune disorders, but has received scant attention in PA. By generally accepted criteria, PA is an excellent example of an organ-specific autoimmune disease. As yet, there is no acceptable single unifying hypothesis which will account for all of the phenomena which have been described in the disease.(ABSTRACT TRUNCATED AT 400 WORDS)

Fundic atrophic gastritis in an elderly population. Effect on hemoglobin and several serum nutritional indicators

The ratio of pepsinogen I to pepsinogen II in the circulation decreases progressively with increasing severity of atrophic gastritis of the fundic gland mucosa. Fasting blood was obtained from 359 free-living and institutionalized elderly people (age range, 60 to 99 years). A pepsinogen I/pepsinogen II ratio less than 2.9, indicating atrophic gastritis, was found in 113 (31.5%) subjects. The prevalence of atrophic gastritis increased significantly with advancing age (P less than .05). Within the atrophic gastritis group, 84 had a pepsinogen I level greater than or equal to 20 micrograms/L, indicating mild to moderate atrophic gastritis, and 29 had a pepsinogen I level less than 20 micrograms/L, indicating severe atrophic gastritis or gastric atrophy. A significant increase in the prevalences of elevated serum gastrin levels (P less than .005), low serum vitamin B12 levels (P less than .005), circulating intrinsic factor antibody (P less than .005), and anemia (P less than .025) was observed with stepwise increases in severity of atrophic gastritis. Subjects with atrophic gastritis exhibited a lower mean serum vitamin B12 level (P less than .05) and a higher mean folate level (P less than .05), but no difference was detected in mean hemoglobin levels or serum levels of iron, ferritin, retinol or alpha-tocopherol. It is concluded that serum pepsinogen I and pepsinogen II levels can be used to determine the prevalence and severity of atrophic gastritis, that atrophic gastritis is common in an elderly population, and that atrophic gastritis is associated with vitamin B12 deficiency and anemia. Further, higher folate levels in atrophic gastritis may be related to an accumulation of 5-methyl tetrahydrofolate in serum due to vitamin B12 deficiency and/or greater folate synthesis by the intestinal flora resulting from bacterial overgrowth secondary to hypo- or achlorhydria.

Vitamin B12 (cobalamin) and folate blood levels in geriatric reference group as measured by two kits

For serum vitamin B12 levels there was little apparent difference between a geriatric healthy reference group and a hospitalized group for the total population studied; however, the hospitalized males did have an increased prevalence of values less than normal range. The frequency distribution for both sexes of the geriatric reference group gave lower range limits than manufacturer's normal range. (68-632 vs 133-708 pmol/L for Becton Dickinson, and 125-609 vs 179-930 pmol/L for Bio-Rad, using 95% non-parametric limits). For folate there was an increased incidence in values of less than normal in the hospitalized group versus the geriatric reference group, but there was no difference in the ranges calculated for the latter compared to either manufacturer's normal range derived from a younger population. Comparison of results by two manufacturers' kit methods confirmed Bio-Rad's claim to increased low-end sensitivity of standard curve in range of clinical interest.

Humoral and cellular immunity to intrinsic factor in myasthenia gravis

Myasthenia gravis (MG) is an autoimmune disease often associated with other autoimmune disorders. A case history of MG with a coexisting atypical megaloblastic anaemia with vitamin B12 deficiency and anti Intrinsic Factor (IF) antibodies, led to a study of humoral and cellular immunity to IF in 81 MG patients. Within this series, 3 other patients had a disturbed humoral and cellular immunity to IF. These 3 patients presented no other features of pernicious anaemia. The possible origins and significance of the anti IF antibodies in MG patients are discussed.

Blocking and binding type antibodies against all major vitamin B12-binders in a pernicious anaemia serum

The simultaneous occurrence of blocking and binding antibodies to intrinsic factor (IF), transcobalamin (TC- II, TC I) and other R type vitamin B12 proteins in the serum of a patient with treated pernicious anaemia (PA) is reported here for the first time. The dialysed and purified immunoglobulin-G (IgG), but not the immunoglobulin-M (IgM), from a PA patient neutralized the total unsaturated vitamin B12 binding capacity (UB12BC) of human gastric juice, saliva and serum and also of rabbit serum, suggesting that the PA IgG contained blocking antibodies against, IF, TC II, TC I and other R-binders. In addition, the PA IgG and IgM preparations contained binding antibodies since they could form macromolecular complexes with 57Co-B12 bound to IF, TC I or TC II so that each one of the latter was totally excluded from Sephadex G-200. The presence of the binding antibodies was further confirmed by the formation of radioactive precipitation lines on agarose with each one of the vitamin B12-binders bound to 58Co-B12. The PA serum did not exhibit any measurable UB12BC after dialysis against 7.5 M guanidine-HCl followed by renaturation with phosphate buffer (pH 7.4). But it did form TC I and TC II complexes with 57Co-B12 when the latter was added during the renaturation step indicating that the serum contained circulating immunoglobulin-TC complexes. The blocking antibodies should be distinguished from the previously described binding antibodies. The blocking of the binding of vitamin B12 to TCs resulted in relatively lower serum vitamin B12 levels in the present case in contrast to the presence of binding antibodies where high serum vitamin B12 levels have been reported. In addition, the binding antibodies form immunocomplexes with TCs which can easily be detected because they can bind radioactive vitamin B12 while the corresponding immunocomplexes of blocking antibodies are hidden because they prevent the binding of the vitamin to TCs.

Autoantibodies to gastrin-producing cells in antral (type B) chronic gastritis

Autoantibodies that react exclusively with the gastrin-secreting cell of human antrum have been detected by immunofluorescence in eight of 106 patients with histologic evidence of chronic atrophic gastritis, Type B, involving mainly the antrum. These antibodies were of the IgG class and of low titer. However, follow-up studies one to two years later showed persistently positive reactions, despite symptomatic treatment. These data support the concept of an autoimmune variant of chronic "antral" gastritis, Type B.

An appraisal of tests for severe atrophic gastritis in relatives of patients with pernicious anemia

The sensitivities, specificities, and predictive values of parietal cell antibody, serum gastrin, and serum pepsinogen I (PG I) for severe atrophic gastritis of the oxyntic gland mucosa have been determined in 171 first-degree relatives of 62 patients with pernicious anemia. Parietal cell antibody had the lowest sensitivity (65%), specificity (87%), and predictive value (44%). A low serum PG I and a high serum gastrin had identical specificities (97%), and similar predictive values (84 vs 83%), but the sensitivity of a low serum PG I was greater than that of a high serum gastrin (91 vs 83%). Parietal cell antibody was found in 19 of 148 relatives without severe atrophic gastritis and occurred as an isolated finding in 17. In contrast, 14 of the 15 relatives with severe atrophic gastritis who had parietal cell antibody also had a high serum gastrin and a low serum PG I. A high serum gastrin together with a low serum PG I had a specificity of 100%. The results recommend serum PG I and serum gastrin, but not parietal cell antibody, as tests for severe atrophic gastritis in relatives of patients with pernicious anemia.

Racial patterns in pernicious anemia. Early age at onset and increased frequency of intrinsic-factor antibody in black women

Pernicious anemia affects primarily elderly northern Europeans, but may affect others more often than previously thought. Therefore, we analyzed the data from 156 documented cases: there were 73 patients of "European" origin, 52 black patients and 31 Latin-American patients. The mean age (+/- 1 S.D.) at presentation among black women, 53 +/- 16 years, was lower than that of all the others (P less than 0.001 in most comparisons), and seven of the 33 black women were less than 40 years old. In addition, 23 of the 24 black women tested had circulating antibody to intrinsic factor. A similar though less striking antibody prevalence (85 per cent) and age pattern (60 +/- 13 years) in Latin-American women did not reach statistical significance. No other group exceeded the usual 55 to 70 per cent prevalence of antibody. These finding suggest a different form of or a different response to the disease in black women and perhaps in Latin-American women.

Platelet Autoimmunity

Autoimmunity to platelets was looked for by complement fixation, antiglobulin consumption, transformation and migration-inhibition techniques. Only the migration-inhibition method gave consistently positive results. The test was positive in nine out of 14 patients with idiopathic thrombocytopenic purpura and all five patients with glandular fever.

Idiopathic late-onset immunoglobulin deficiency. Clinical observations in 50 patients

Fifty patients with late-onset idiopathic immunoglobulin deficiency were studied and the frequency of various clinical associations and complications was observed. Men and women were equally affected, although the age at onset in men peaked in the third decade whereas it was more uniformly distributed in women. Sinobronchopulmonary infections were common and were caused by Haemophilus influenzae. Diplococcus pneumoniae, Streptococcus pyogenes and Staphylococcus aureus: bronchiectasis occurred in 28 per cent. Thirty patients (60 per cent) had diarrhea, which was often associated with steatorrhea, giardiasis, achlorhydria, abnormal Schilling tests and morphologic abnormalities on small bowel biopsy specimens, including nodular lymphoid hyperplasia; three patients had pernicious anemia. In the 20 patients without diarrhea these abnormalities were not observed except for giardiasis in one patient and achlorhydria in two patients. Cholelithiasis occurred in both groups in about a third of the patients tested. A high degree of susceptibility to neoplasia was noted. Thyroid abnormalities, including primary hypothyroidism and Graves' disease, were observed in six patients. Additional occasional findings were vitiligo, keratoconjunctivitis sicca and arthritis. Splenomegaly occurred in 14 (28 per cent) patients. The percentage of B lymphocytes in the blood was determined in 10 patients; it was normal or slightly decreased in eight patients and low in two patients.

Some trends in schools of public health

Some of the recent changes in the schools of public health include: an increasing number of schools and of graduates; a decrease in both the awarding of the MPH degree as compared with other masters degrees, and the DrPH degree as compared with the PhD; a trend toward lengthening the time for achieving the MPH degree; an increase in part-time study for graduate degrees; institution of undergraduate programs and external masters degree programs; a thrust toward greater continuing education activities; and a broadened base for the student population in terms of the heterogeneity of professional backgrounds and prior experience, a wider age range with more younger students, more women students, fewer foreign students, and an increase in minority representation.

Cell-mediated immunity to intrinsic factor in autoimmune disorders

Evidence of cell-mediated immunity to gastric intrinsic factor was present in 86% of patients with pernicious anaemia and in at least 13% of patients with hyperthyroidism, 21% of patients with atrophic gastritis, and four out of nine (46%) patients with hypogammaglobulinaemia. Controls gave negative results. The four patients with hypogammaglobulinaemia and cell-mediated immunity to intrinsic factor had evidence of impaired gastric function.