Immunodeficiency and inborn disorders of vitamin B12 and folate metabolism

PURPOSE OF REVIEW

Immune dysfunction, including severe combined immunodeficiency, has been described in genetic disorders affecting the metabolism of the vitamins cobalamin (vitamin B12) and folate. We have reviewed reports of clinical findings in patients with a number of inborn errors of cobalamin or folate metabolism, specifically looking for immune problems.

RECENT FINDINGS

There is little evidence that immune function is affected in most of the disorders. Exceptions are Imerslund-Gräsbeck syndrome and hereditary folate malabsorption (affecting intestinal absorption of cobalamin and folate, respectively), transcobalamin deficiency (affecting transport of cobalamin in blood and cellular cobalamin uptake), and methylenetetrahydrofolate dehydrogenase 1 deficiency (catalyzing cytoplasmic interconversion of reduced folate coenzyme derivatives).

SUMMARY

Although some inborn errors of cobalamin or folate can be associated with immune dysfunction, the degree and type of immune dysfunction vary with no obvious pattern.

Predictivity of Autoimmune Stigmata for Gluten Sensitivity in Subjects with Microscopic Enteritis: A Retrospective Study

Non-celiac gluten sensitivity (NCGS) is an emerging gluten-related condition. We investigated whether the presence of autoimmune stigmata in a group of patients with clinical suspicion of NCGS and a histological picture of microscopic enteritis (ME) could be a predictive factor of NCGS. Patients with ME were followed up by periodical examinations. At baseline, we collected data about previous clinical history, including autoimmune diseases. NCGS was diagnosed according to Salerno criteria; other causes of ME were diagnosed according to well-established protocols. Patients with celiac disease were excluded. Student's and chi-square tests were used in univariate analysis. Kaplan-Meier curves and Cox regression were used to estimate hazard ratios (HR). Sixty-three patients were included. Twenty-two had a final diagnosis of NCGS; the remaining 41 had non-gluten-related causes of ME. Prevalence of autoimmune thyroiditis was higher among NCGS patients (40.1%) than in other ME (14.6%; p = 0.03). NCGS showed higher positivity rate for anti-gliadin (27.3% versus 2.5%; p = 0.006) and anti-nucleus (45.4% versus 12.2%; p = 0.005). Autoimmune thyroiditis had a non-significant trend (p = 0.06) for NCGS diagnosis, (HR = 2.4). Both anti-gliadin (HR = 2.4; p = 0.04) and anti-nucleus (HR = 2.7; p = 0.04) were directly associated with NCGS diagnosis. In conclusion, NCGS may have a cohort of autoimmune stigmata that can precede its diagnosis.

CVID enteropathy is characterized by exceeding low mucosal IgA levels and interferon-driven inflammation possibly related to the presence of a pathobiont

Common variable immunodeficiency (CVID), the most common symptomatic primary antibody deficiency, is accompanied in some patients by a duodenal inflammation and malabsorption syndrome known as CVID enteropathy (E-CVID).The goal of this study was to investigate the immunological abnormalities in CVID patients that lead to enteropathy as well as the contribution of intestinal microbiota to this process.We found that, in contrast to noE-CVID patients (without enteropathy), E-CVID patients have exceedingly low levels of IgA in duodenal tissues. In addition, using transkingdom network analysis of the duodenal microbiome, we identified Acinetobacter baumannii as a candidate pathobiont in E-CVID. Finally, we found that E-CVID patients exhibit a pronounced activation of immune genes and down-regulation of epithelial lipid metabolism genes. We conclude that in the virtual absence of mucosal IgA, pathobionts such as A. baumannii, may induce inflammation that re-directs intestinal molecular pathways from lipid metabolism to immune processes responsible for enteropathy.

[Autoimmune enteropathy]

Autoimmune enteropathy (AIE) is characterized by protracted diarrhea, malabsorption, immunomediated damage to the intestinal mucosa, and unresponsiveness to changes in diet. The disease is mainly manifested in the small intestine. Lymphocyte deposits are present on the mucous membrane, and anti-enterocyte or anti-goblet cell antibodies have been described in the majority of affected persons. AIE occurs primarily in infants. Immunosuppressive drugs have been used with varying success. The prognosis of AlE is dependent on the degree of severity of the damage to the intestinal mucosa and extraintestinal symptoms and diseases associated therewith.

[Gastrointestinal manifestations in patients with primary immunodeficiencies causing antibody deficiency]

INTRODUCTION

Primary immunodeficiencies can lead to gastrointestinal manifestations that are still not well defined.

OBJECTIVE

To analyze gastrointestinal manifestations associated with primary immunodeficiencies.

MATERIAL AND METHODS

We performed a retrospective study that included patients diagnosed with primary antibody deficiencies in a third-level hospital. The patients were divided into two groups: isolated IgA deficiency and common variable immunodeficiency syndrome (CVIS). The timing of presentation and type of gastrointestinal symptoms were analyzed.

RESULTS

There were 57 patients: 20 with CVIS (35%) and 37 with isolated IgA deficiency (65%). Diagnosis was made in the pediatric age in 17 patients, of whom 13 had isolated IgA deficiency. In 84% of the patients, diagnosis of immunodeficiency was made before the development of gastrointestinal manifestations. Digestive symptoms were found in 74% of the patients, the most frequent being diarrhea. In 46% of the patients, digestive disease was confirmed, mainly through endoscopy. Celiac-like lesions, chronic atrophic gastritis, ulcerative colitis-like disease and Crohn's disease were more common in CVIS. In isolated IgA deficiency, Helicobacter pylori-positive chronic gastritis predominated. Mean age was significantly higher (36 vs. 24 years, p=0.02) and IgA titer significantly lower (17 vs. 34UI/ml; p=0.008) in patients with associated gastrointestinal disease.

CONCLUSIONS

Gastrointestinal symptoms are frequent and lead to endoscopic diagnosis in half of patients with primary immunodeficiencies. Ulcerative colitis, and celiac- and Crohn's-like disease are atypical entities that occur in CVIS.

Common Variable Immunodeficiency

BACKGROUND

Malabsorption syndrome often develops in patients with common variable immunodeficiency (CVID). Why structural damages appear in some CVID patients and not in others is not fully understood. Memory B cells (MBs) are responsible for the production of specific antibodies, and their defects have previously been related to autoimmune, granulomatous, and lymphoproliferative complications of CVID. The objective of this study was to ascertain whether a relationship exists between MB defects and the clinical outcome of respiratory and intestinal involvement in these patients.

METHODS

Forty-one CVID patients were grouped as follows, according to the quantification of peripheral MBs: the MB2 group (n = 7) included patients with normal MBs; the MB1 group (n = 16) included patients with low switched MBs; and the MB0 group (n = 18) included patients with absent/low MBs. The clinical outcome of respiratory and intestinal involvement of patients was then compared among the three groups.

RESULTS

In the MB0 group, chronic lung disease (ie, bronchiectasis and diminished FVC and/or FEV1) developed in 50% of patients vs 13% in the MB1 group and 0% in the MB2 group (p < 0.05). In the MB0 group, malabsorption syndrome or chronic noninfectious diarrhea developed in 50% of patients vs 19% in the MB1 group and 0% in the MB2 group (p < 0.05). No differences were found among the three groups for age at onset of symptoms, delay in diagnosis/treatment, months of follow-up/treatment, and prediagnostic serum IgG concentration.

CONCLUSIONS

Alterations in MB count appear to be associated with a severe clinical outcome of respiratory and intestinal involvement in CVID. The MB count could be a useful laboratory parameter for orienting the prognosis and management of CVID patients.

Cytokine responses in broiler lines that differ in susceptibility to malabsorption syndrome

1. Based on earlier studies it was hypothesised that there is an immunological basis for the differences in susceptibility to malabsorption syndrome (MAS). A study was conducted to investigate base-line and MAS-induced cytokine levels in the intestine of broilers that differ in MAS susceptibility. 2. The transcription of cytokine mRNA in the intestine was quantified using a real-time polymerase chain reaction (PCR) method. At different time points after disease induction the intestines of broilers were investigated for expression of interleukin (IL)-2, IL-6, IL-8, IL-18 and interferon (IFN)-gamma. Age-matched non-MAS-induced chickens served as controls. 3. Control chickens from a MAS-resistant line had higher concentrations of mRNA for IL-2, IL-6, IL-18 and IFN-gamma in the small intestine while no difference between the lines was found for IL-8. After induction of MAS the relative amounts of IL-2, IL-6, IL-8 and IFN-gamma mRNA increased more in the intestines of the susceptible line than in the gut of the resistant line. 4. We suggest that differences in cytokine mRNA in the base-line situation and in MAS-induced conditions indicate a difference in immune response regulation in the two broiler lines. This difference in response could lead to the difference in susceptibility to MAS.

Prospective screening for biopsy proven coeliac disease, autoimmunity and malabsorption markers in Belgian subjects with Type 1 diabetes

AIMS

To determine prospectively the prevalence of biopsy proven coeliac disease (CD) in an adult Type 1 diabetic population from Belgium with regards to associated auto-immunity and malabsorption.

METHODS AND RESULTS

Determination in 400 Type 1 diabetic patients of serum anti-endomysial and/or anti-transglutaminase auto-antibodies. All subjects with abnormal serology underwent an intestinal biopsy. Ten patients (2.5%) had positive antibodies. Diagnosis of CD was confirmed by an intestinal biopsy. Eight patients were symptom-free, although laboratory findings suggesting malabsorption were prominent in the presence of CD [microcytic anaemia, iron and folate deficiencies, low levels of 25(OH)vitamin D3, calcium and cholesterol]. Other auto-immune conditions, especially vitiligo, were found in patients with CD.

CONCLUSIONS

Asymptomatic coeliac disease occurs frequently in adult Type 1 diabetic patients, and is often associated with subclinical malabsorption. Screening should be part of routine evaluation, to implement life-long dietary gluten avoidance.

Common variable immunodeficiency (CVID) presenting with malabsorption due to giardiasis

Common variable immunodeficiency is characterized with B-cell and T-cell dysfunction and hypogammaglobulinemia. Recurrent bacterial infections, such as otitis media, chronic sinusitis and recurrent pneumonia due to diminished immunoglobulin (Ig) levels and impaired antibody production are frequently observed in common variable immunodeficiency. Almost half of the patients with common variable immunodeficiency have problems related to the gastrointestinal system. A 39-year-old woman was referred to our department with the complaint of chronic diarrhea. She had experienced diarrhea without mucus or blood in the last year and had lost 30 kg. In her medical history, she had suffered from recurrent upper and lower respiratory infections like sinusitis, otitis media and pneumonia since childhood. Serum immunoglobulin levels were low. There were no parasites or ova in her stool examinations. Esophagogastroduodenoscopy detected widespread macroscopic nodular appearance on duodenum, and biopsies from the duodenum revealed giardiasis invading the tissue. She was diagnosed as common variable immunodeficiency. After metronidazole therapy and intravenous immunoglobulin infusion was started, her diarrhea attacks ceased and she regained her normal weight. Common gastrointestinal system problems in patients with common variable immunodeficiency are lactose intolerance, lymphoid hyperplasia/diffuse lymphoid infiltration, loss of villi and infection, especially with Giardia lamblia. Giardiasis may lead to severe mucosal flattening and sometimes to lymphoid hyperplasia at the lamina propria of the duodenum. Medical history should be evaluated carefully regarding recurrent respiratory infections. In such cases with chronic diarrhea, common variable immunodeficiency should be kept in mind as a possible cause.

[APS I--a severe autoimmune disease with endocrine and non-endocrine symptoms]

Autoimmune polyglandular syndrome type I (APS I) is an autosomal recessive disorder characterized by a combination of autoimmune manifestations affecting endocrine and non-endocrine organs. APS I usually presents in childhood. The three most common manifestations are chronic mucocutaneous candidiasis, hypoparathyroidism and Addison's disease. At least two of these must be present to fulfill the diagnostic criteria of this syndrome. The spectrum of other associated diseases includes gonadal insufficiency, alopecia, vitiligo and chronic active hepatitis. APS I is caused by a mutation in the AIRE-gene (autoimmune regulator) located on chromosome 21. Analysis of specific autoantibodies against intracellular enzymes, particularly enzymes in the synthesis of steroids and neurotransmittors, can be used in the diagnosis of APS I and to predict different manifestations of the disease.

Cellular immune response in the small intestine of two broiler chicken lines orally inoculated with malabsorption syndrome homogenates

We studied the cellular immune response against malabsorption syndrome (MAS) in two broiler chicken lines, A and B. We determined the number of pan T-lymphocytes (CD3), helper T-lymphocytes (CD4), cytotoxic T-lymphocytes (CD8) and macrophages/monocytes in the small intestine in the first 2 weeks after oral inoculation of two MAS homogenates, MAS80 and MAS97-1. The immune cells were detected on cryostat tissue by immunohistochemistry and counted by villus area. In trial 1, we compared the two broiler lines for weight gain depression, intestinal lesion and number of CD3, CD4, CD8 cells and macrophages/monocytes after MAS80 inoculation. Although there was no significant difference in weight gain depression between the two broiler lines, line B had significantly higher numbers of CD8+ T-cells per villus area than had line A. To confirm part of the results of trial 1, trial 2 was done in which we compared different homogenates in broiler line B. Broiler line B was orally inoculated with either MAS97-1, intestinal homogenate obtained from healthy chickens (healthy homogenate), or phosphate buffered saline (PBS). In this trial, the MAS97-1 homogenate also induced weight gain depression and intestinal lesions, whereas the "healthy homogenate" and PBS did not induce weight gain depression or intestinal lesions. The broilers inoculated with MAS97-1 homogenate had significantly more CD8+ T-cells per villus area than had broilers inoculated with "healthy homogenate" or PBS. Increased CD8+ T-cells per villus area in the affected small intestines of broilers suggests an increase of cytotoxic T-cell activity.

[Biermer's disease without anemia: apropos of 2 cases manifested as glossitis with macrocytosis]

Although it is recognized that glossitis is a classical sign of pernicious anemia, occurring in the evolution of this disease, it is unfrequent for this sign to reveal this affection. We report two cases where diagnosis was evacuated on the presence of glossitis and macrocytosis despite absence of anemia. Confirmation was done by low serum cobalamin level, gastritis atrophy and presence of intrinsic factor antibody. We emphasize that increased clinical suspicion may lead to early diagnosis even if anemia is lacking.

Food-induced malabsorption syndromes

A syndrome of chronic diarrhea, vomiting, and failure to thrive was described 35 years ago. The syndrome was caused by damage in the jejunum after ingestion of cow's milk. Symptoms appeared in young infants shortly after introduction of cow's milk formula. Patients had moderate steatorrhea, decreased absorption of D-xylose, and, often, iron-deficiency anemia and hypoproteinemia. They had strong IgA and IgG antibodies to cow's milk. IgE antibodies to cow's milk were negative, as a rule. Indicators of cell-mediated immune reaction to cow's milk proteins were often positive. Patients were tolerant to cow's milk by the age of 3 years. Malabsorption was due to damage to the jejunal mucosa: Varying villus atrophy was associated with inflammation in surface epithelium and lamina propria. The epithelial cell renewal rate increased. Surface epithelial cells decreased in height, with short, furry microvilli and large aggregates of lysozymes. The number of intraepithelial lymphocytes was markedly increased, but normalized during cow's milk elimination. Most of these lymphocytes had alpha/beta T-cell receptors, and many were cytotoxic. Some specimens had an increase in gamma/delta T-cell receptor-bearing cells. In the lamina propria, CD4+ cells predominated, and some of them were activated. IgA- and IgM-containing cells were markedly increased during cow's milk exposure, but IgE cells were not abnormal. The density of eosinophils was moderately increased. Secretion of interferon-gamma by cells isolated from patients' intestines was markedly increased. Morphologic and immunologic findings suggest that T-cell-mediated reaction to proteins in cow's milk is present in the small intestines of patients with this syndrome and causes this enteropathy.

[Possibilities of the use of parameters of membrane assembly of immunoglobulin receptors of B-lymphocytes in the differential diagnosis of intestinal diseases in children]

Children with different forms of enteric malabsorption were examined using an original method for assessing the parameters of the process of membrane assembling for immunoglobulin receptors of B-lymphocytes, which helps single out several additional criteria for the differential diagnosis of variants of the malabsorption syndrome. The authors consider the phase coefficients characterizing each stage and the general coefficient reflecting the regularities of the kinetics of membrane assembly of receptors in general to be the most essential. Use of this method in pediatrics offers new potentialities in the differential diagnosis, prediction of disease course, and monitoring of the treatment efficacy.

[Proliferating cell nuclear antigen (PCNA) in patients with malabsorption syndrome: comparative study with morphometric parameters]

The study of small bowel mucosa is routine in the study of patients with malabsorption. We report 16 children aged from 8 months to 6 years old (2 with giardiasis, 8 with primary malnutrition and 5 with celiac disease) in whom a morphometric and PCNA immunostaining was performed in the small intestinal biopsy. Positivity for PCNA was found in the lower portion of the crypts reaching 156 microns of heigh in patients with giardiasis, 103 microns in primary malnutrition and 182 microns in celiac disease (p < 0.01 compared to primary malnutrition). A negative and significant correlation was found between the degree of architectural disorder (expressed the mucosal index) and the proliferative portion of the crypts (expressed as the percentage of PCNA(+) crypts. We propose these methods as complements to the small bowel mucosa histopathological study in the diagnosis of celiac disease, to assess the degree of architectural disorder and the proliferative activity.

[The local humoral immune system in patients with malabsorption syndrome]

Content of IgA, IgG, IgM, C3 and C4 components of complement, properdin factor B, acid glycoprotein, alpha 1-antitrypsin, transferrin and ceruloplasmin were studied using immunochemical procedures in blood serum, gastric and duodenal contents of healthy persons and of patients after stomach resection. In patients with symptoms of malabsorption concentration of IgA and IgG was drastically increased in gastric and duodenal contents by 51% and 188%, respectively, and by 53% and 371%, respectively. Local activation of the complement system was also observed, which involved an increase of C3 component in stomach and small intestine by 122% and 31%, respectively. As a result of postoperative anastomositis content of albumin and the properdin factor B was distinctly increased in the duodenum. The data obtained suggest that studies of various functional proteins in gastric and duodenal contents are recommended for evaluation of a disease genesis as well as for diagnosis of acute local inflammation.

[Selective IgA deficiency and malabsorption. Review of the literature apropos of a case]

One of the most common primary immunodeficiencies is the selective deficiency of IgA, which is present in very variable clinical conditions. This situation had conducted to different criteria with respect to the clinical meaning in a particular patient. The association of immunodeficiency of IgA and intestinal malabsorption is reported as statistically significant in the international literature. Nevertheless, the precise pathogenic connection between them is unknown. The relationship between bowel and immune system is reviewed here, and illustrated with the clinical case of a six-year old girl who presented with malabsorption and selective deficiency of IgA.

Leukocytes in the intestinal epithelium: an unusual immunological compartment revisited

Intraepithelial lymphocytes (IEL) are characterized by significant heterogeneity in morphology, surface antigen expression, and function. Although IEL can express T cell markers including the T cell receptor (TcR), their relationship to peripheral T cells is not clear. The finding of IEL in athymic nude mice first suggested that a number of IEL may be thymic-independent. The identification of the gamma/delta TcR heterodimer on IEL further suggested that these cells are part of a distinct population of epithelial-associated lymphocytes, many of which express the gamma/delta TcR. We review the nature of the V gamma gene usage in IEL and highlight the differences between different gamma/delta T cell populations. The thymic independent nature of these gamma/delta cells is discussed and compared to that of the alpha/beta TcR expressing IEL. The finding that some alpha/beta IEL can develop independent of thymic processing suggests that IEL are characterized by a unique collection of T cells that may undergo differentiation within the intestinal compartment. The ability to distinguish T-dependent from T-independent IEL raises the possibility of identifying the functional nature of these two IEL lineages. We propose that the ability of IEL to potentially undergo repertoire selection in the intestine could allow for the development of mucosal T cells uniquely adapted to function in this environment.

Differentiation of coeliac disease and other malabsorption diseases using specific serum antigliadin IgG subclass profiles and IgA1 levels

The differential diagnostic potential of serum gliadin-specific IgG subclass antibodies was assessed by comparing the antigliadin IgG1, 2, 3, 4 profile at different stages of coeliac disease with that of gastro-intestinal infection and also conditions associated with increased intestinal permeability. The IgG subclass profile of untreated coeliac disease was found to be the same as in healthy controls (IgG1 approximately IgG2 > IgG3 > IgG4), with only the magnitude of the individual subclass responses being increased in coeliac patients. Coeliac adults and children on gluten-free diets had different antigliadin IgG subclass profiles with IgG2 being elevated. Increased intestinal permeability or recent gastro-intestinal infection did not alter the antigliadin subclass profile from that observed in healthy individuals. Assessment of the diagnostic potential of antigliadin IgA1 and IgG1-4 measurements in screening for coeliac disease demonstrated that measurement of subclasses of gliadin-specific IgA and IgG was less sensitive and specific compared with the combined use of total antigliadin IgA and IgG. Therefore it is suggested that IgG subclasses should not be used for routine screening for coeliac disease.

[Immunohistochemical studies in contaminated small bowel syndrome]

This study was undertaken to evaluate the number of the immunoglobulin producing cells in the lamina propria of the small intestine by immunocytochemical techniques, using peroxidase-antiperoxidase (PAP) complex in normacid patients with CSBS. 25 patients were studied including 13 patients with bacterial overgrowth, where the bacterial concentration was higher than 10(4) colony forming units/ml, and 12 subjects with normal bacterial concentration, served as control. The patients with CSBS were treated with antibiotics according to the antibiotic resistance. After treatment the luminal bacterial concentrations was lower than 10(4) cfu/ml in 7 of 13 patients (CSBS I. group). In 6 patients the bacterial concentration remained high (CSBS II. group). The immunoglobulin producing cells were determined in biopsy specimens taken from the lower part of duodenum. The number of the IgA and IgM producing immunocytes was significantly decreased only in the CSBS II. group. Our results show that temporary immunological alterations may play an important role in the mechanism of the recurrent CSBS.

Single and combined infections of specific-pathogen-free chickens with infectious bursal disease virus and an intestinal isolate of reovirus

The susceptibility of 1-day-old and 7-day-old specific-pathogen-free chickens to infection with a virulent strain of infectious bursal disease virus (IBDV) or an intestinal isolate of avian reovirus, or a combination of the two, was investigated. Chickens infected with IBDV and reovirus had more severe pathological lesions than chickens infected with either virus alone, and prior infection with IBDV enhanced the pathogenicity of enteric reovirus. Virus recovery was attempted from bursa, spleen, thymus, liver, intestine, pancreas, cecal tonsils, heart, and tarso-metatarsal tendons. Viruses were recovered from all tissues sampled for either IBDV or reovirus isolation, and indications were that infection with IBDV before infection with reovirus led to longer persistence of reovirus in some tissues. Antibodies to IBDV or reovirus were measured by the virus neutralization test and enzyme-linked immunosorbent assay. Chickens infected with IBDV had lower (P less than 0.05) antibody responses to reovirus than chickens infected with reovirus alone.

Expression of disulfide-linked and non-disulfide-linked forms of the T cell receptor gamma/delta heterodimer in human intestinal intraepithelial lymphocytes

Immunohistochemistry has been used to investigate disulfide- and non-disulfide-linked forms of the T cell receptor gamma/delta heterodimer (TcR gamma/delta) in blood and intestinal epithelium of normal human small intestine, intestine of patients with untreated coeliac disease (in whom T cells expressing TcR gamma/delta are disproportionately raised), intestine of patients with tropical malabsorption, and in the human fetus. In blood from adult volunteers, 90% of T cells expressing TcR gamma/delta use the disulfide-linked form. In contrast in the epithelium in normal small intestine, coeliac disease and tropical malabsorption, most of the T cells expressing TcR gamma/delta use the non-disulfide-linked form. This is especially prominent in untreated coeliac disease where the increase in TcR gamma/delta T cells is mainly restricted to those using the non-disulfide-linked form. In human fetal small intestinal epithelium, however, only cells using the disulfide-linked form are present. These variations in expression of different forms of TcR gamma/delta in the gut epithelium in different conditions suggests that antigen, or some as yet undefined factor may determine the frequency of each subpopulation.

Primary bile acid malabsorption. Histologic and immunologic study in three patients

Three patients are presented with a history of chronic watery diarrhea due to bile acid malabsorption, proved by the tauro-23[75Se]selena-25 homocholic acid test and an unequivocal response to cholestyramine therapy. Fecal fat tests, Schilling tests, and barium studies of the small intestine and colon were all normal. Jejunal biopsies were normal but multiple biopsies of the terminal ileum, performed by retrograde ileoscopy, showed uniform crypt hyperplastic villous atrophy and features of colonic metaplasia with increased mononuclear infiltration of the lamina propria. All 3 patients demonstrated evidence of abnormal immune function, including the presence of serum autoantibodies, circulating immune complexes, and hypocomplementemia. One patient had Sjögren's syndrome. This disorder, which might be immunologically mediated, should be called primary bile acid malabsorption and should be distinguished from other ileal disorders.

[Selective immune deficiency in IgA. Intestinal malabsorption syndrome and mixed connective tissue disease]

We report the case of a 22-year old unmarried woman who presented with selective IgA immune deficiency, moderate intestinal malabsorption syndrome with pseudo-atrophy of the villi, and mixed connective tissue disease. Although immune deficiency and malabsorption syndrome are frequently associated, association with an autoimmune disease is rare and we were unable to find any case of association with a connective tissue disease in the literature.

Rotavirus persistence in malabsorption syndrome: virus assessment by immunofluorescence in small intestine biopsies in relation to antibody titres

Results of quantitative immunofluorescence (IF) in small intestine biopsies and the serum antibody titres as detected by indirect Rotalex test in rotavirus infections were compared using regression and correlation analysis. Based on the significance of the statistically established correlation (r = 0.76; n = 30) between immunohistological identification of rotavirus antigen and determination of serum antibody levels, the indirect Rotalex test may be applied as a diagnostic tool to avoid biopsies in productive rotavirus persistence.

Humoral response to wheat protein in patients with coeliac disease and enteropathy associated T cell lymphoma

Features that might distinguish uncomplicated coeliac disease from enteropathy associated T cell lymphoma were investigated. Of 76 patients with coeliac disease, 71 (93%) had raised levels of alpha gliadin antibody and all responded clinically and histologically to treatment with a gluten free diet. In contrast, none of 16 patients with enteropathy associated T cell lymphoma had raised levels of alpha gliadin antibody, and treatment with a gluten free diet resulted in histological improvement in one and transient clinical improvement in six patients. The ratio of women to men was 2.2:1 in the group with coeliac disease and 1:1.6 in the patients with enteropathy associated T cell lymphoma. Thus patients with enteropathy associated T cell lymphoma do not display a humoral immune response to wheat protein (alpha gliadin), rarely respond to a gluten free diet, and are often men. Patients with uncomplicated coeliac disease usually have raised levels of alpha gliadin antibody, always respond to a gluten free diet, and are frequently women. These findings suggest the presence of two separate forms of enteropathy: one is benign and sensitive to wheat protein whereas the other runs a malignant course.

[Atrophy of the duodeno-jejunal mucosa in cow's milk protein intolerance. Importance of cell-mediated immunologic factors]

Cow's milk sensitive enteropathy has been described several times but in spite of that, it is still a problem concerning the pathogenesis. Our study involves the children hospitalized from 1974 to 1984 in the First Department of Pediatrics, University of Modena. Patients were suffering from chronic diarrhea and malabsorption. At the first biopsy each child showed atrophy of the small intestinal mucosa. All patients had been fed fed with gluten. We have followed the protocol for Celiac Disease's diagnosis; we found proved 85% of cases, excluded 15%. These last cases may be considered as cow's milk sensitive enteropathy. We catamnestically considered all the clinical and laboratory data of the two groups in the purpose of selecting significative parameters for a differential diagnosis. The data meaning fully different between the two groups resulted: family history of allergy, recurrent infections, positive occult blood in the stools, eosinophils in blood greater than 400/mm3 serum IgE value greater than 97 degrees P X (p less than 0.01). On the ground of recent studies the involvement of the cell-mediated immunity in cow's milk sensitive enteropathy is supposed.

Spontaneous cell-mediated cytolysis by peripheral blood cells obtained from whole-body chronically irradiated beagle dogs

The level of natural killer (NK) activity of continuously gamma-irradiated (whole body) beagle dogs and their nonirradiated controls was studied. For analytical purposes, irradiated dogs were segregated into groups according to their clinical status: clinically normal, hypocellular, or with acute non-lymphocytic leukemia. Since unirradiated control animals exhibited a wide range of NK responses, the data from each irradiated animal were compared to its own age-matched or litter-matched unirradiated control. Of the eight clinically normal irradiated dogs (median = 146% activity of control) only one animal had a NK activity lower than that of its control. The hypocellular group (n = 5, median = 21.8% of control) and the leukemic group (n = 4, median = 52.5% of control) each contained one responder with higher activity than its control. The difference between the percentage of control of the clinically normal and clinically abnormal dogs was found to be significant (P less than 0.05). There is a negative correlation between the NK results obtained and the total accumulated dose of radiation at the time of sampling (correlation coefficient = -0.739, P less than 0.01), suggesting a radiation effect upon natural killer activity, which is evidence by enhancement at lower doses and depression at higher doses of irradiation.

Gastrointestinal hypersensitivity to cow's milk protein: the diagnostic value of gut function tests

Thirty-six children with suspected gastrointestinal hypersensitivity to cow's milk protein were investigated before and after challenge with cow's milk protein by one or more of four tests of gut function: the appearance of small bowel mucosa, mucosal disaccharidase levels, a 1-h blood-xylose test, and a 50 g-lactose breath-hydrogen test. These tests were not always abnormal in children who had definite adverse reactions to milk. Conversely changes were seen in some with negative milk challenges. Although small bowel biopsy, assessment of disaccharidase activity and perhaps the breath-hydrogen test have an important place in the pre-challenge assessment to exclude other causes of gastrointestinal symptoms, these gut function tests and the 1-h xylose test done following milk provocation do not appear to have any advantage over careful clinical observation.

Early decrease in total hemolytic complement activity (CH100) after fasting or intestinal bypass in the rat

An evaluation of total hemolytic complement activity (CH100) after fasting or intestinal bypass was performed in rats. The experiment lasted 6 days. Three groups, of 5 animals each, were studied. On the 1st day, basal values of total complement (TC), albumin and body weight were determined. Group A received normal, ad libitum feeding, group B started on a 'water only' diet, group C underwent intestinal bypass. On the 4th and 6th day the parameters were assessed. TC mean values were significantly lower in groups B and C, as compared to group A, on the 4th as well as on the 6th day (p less than 0.01 by Mann-Whitney's U test). Body weight showed a similar trend. Differences in albumin were never statistically significant. Limitations of the analytical method are discussed. The data show that fasting or bypass-induced malabsorption may determine an early decrease in total hemolytic complement activity, though a development of an immune deficiency is not proved.

Toxicity mechanisms of wheat and other cereals in celiac disease and related enteropathies

This paper is a critical appraisal of current theories on the mechanisms of toxicity of wheat and other cereals in celiac disease and some related enteropathies. The "peptidase deficiency," "primary immune defect," and "gluten-lectin" theories on celiac disease are examined and critically discussed on the basis of the relevant data available in 88 references. Special attention has been paid in this review to the nature of the cereal components triggering the appearance of toxic symptoms and signs in celiac disease as well as to underlying action mechanisms. The gluten-lectin theory is the one best able to explain, in addition to celiac disease, some secondary intolerances that may occur in temporarily predisposed individuals as a consequence of several causes, including viral hepatitis and intestinal infections, as well as the occurrence of intestinal lesions in healthy subjects administered very high amounts of gluten.

Performance of broiler progeny of breeder flocks vaccinated with inactivated oil emulsion malabsorption syndrome virus vaccine

Broiler breeder pullets were vaccinated at 20 to 24 weeks of age with an inactivated, oil emulsion vaccine containing the CO8 strain of avian reovirus. The vaccination induced a high and uniform antibody response that peaked 4 to 5 months postvaccination and persisted up to 11 months postvaccination. Broiler production parameters in progeny of vaccinated breeders were compared weekly with parameters of the total broiler production. There was a consistent improvement in body weight at processing time and a reduction in total production cost in progeny of vaccinated parents. There was also a reduction of percent of parts condemned during the first part of the trial. There were no consistent differences in feed conversion or condemnation of whole carcasses. Progeny of vaccinated parents had reduced livability. This effect was interpreted to be due to the smaller egg size of young breeder flocks.

[Severe malabsorption syndrome and exudative enteropathy in hypogammaglobulinemia: complete involution with intravenous immunoglobulin substitution]

A 35 year old woman with primary hypogammaglobulinaemia developed intestinal villous atrophy, a severe malabsorption syndrome, osteomalacia and protein-losing enteropathy. The syndrome did not respond to treatment with antibiotics, vitamins, or gluten free diet. Regular intravenous administration of a native immunoglobulin preparation induced continuous elevation of IgG serum levels above 240 mg/dl. This led to rapid, complete and persistent normalisation of all clinical symptoms and pathologic findings. Additional therapy was not required. Side effects of the treatment that has now been maintained for 48 months were not observed.

Intestinal cow's milk allergy

Cow's milk allergy (CMA) is multifaceted disease representing systemic, skin or gastrointestinal reactions to cow's milk (CM) protein. This article shortly reviews the intestinal form of CMA (ICMA). According us the child is allergic to CM when the immunologic reaction to CM is associated with clinical symptoms. The incidence of CMA is 1.3-1.9% in general, but the ICMA only 0.6 pro mille among the children less than six months of age. The majority of infants shows symptoms within a month of starting CM feeding. The majority of children with CMA have gastrointestinal symptoms. Manx of these infants has additionally dermatological symptoms and some respiratory symptoms. The mode of onset is often acute diarrhoea and vomiting, as in acute gastroenteritis. Laboratory findings indicate iron deficiency anemia in 20-70%. Half to two thirds of infants with chronic diarrhoea have moderate to severe steatorrhoea. The morphologic lesion in the gastrointestinal tract in ICMA is widespread, often being present from stomach to rectum. Jejunal lesion is most severe in the proximal part of the intestine and nowadays most patients have only partial villous atrophy or slight changes of the villi. Both the epithelium and the lamina propria of the jejunum are infiltrated with inflammatory cells. The morphology of the small intestine speaks for a strong immune reaction which leads increased destruction of surface epithelial cells. We recommend elimination of CM proteins to the age of 1.5 to 2 years. Most patients tolerate CM by the age of 2 years without symptoms. Prolonged breast-feeding and avoidance of early contact with CM are important in reducing the severity and frequency of CMA.

[Acquired hypogammaglobulinemia and malabsorption with villous atrophy sensitive to a gluten-free diet]

The observation of a 21 year-old man with primary common variable hypogammaglobulinemia and total villous atrophy is reported. Gluten withdrawal induced considerable improvement in malabsorption and mucosal damage. However, protein-losing enteropathy, nodular lymphoid hyperplasia and immunoglobulin deficiency were persistent. To our knowledge, improvement on gluten-free diet has been reported until now in 18 previous cases. This report illustrates the links between immunodeficiency and malabsorption, which are discussed.

In vitro immune cell function in six cases of immunoproliferative small intestinal disease after long term remission

We have studied several parameters of in vitro immune cell function in peripheral blood mononuclear cells from six patients with immunoproliferative small intestinal disease after long term remission. We have observed two groups of patients with different patterns of response. (a) After stimulation with pokeweed mitogen (PWM) and Staphylococcus aureus, three patients showed a significant reduction of the Ig synthesis (A, G and M) and the proliferative response. In two of them, we found increased spontaneous suppressor T cell activity. In the third case, the diminished response could not be attributed, according to our assays, either to suppressor T cells, lack of T helper activity (although the number of OKT4+ cells was diminished) or an intrinsic B cell defect. The three patients showed normal or augmented NK activity and an inversion of the OKT4+/OKT8+ ratio was detected in two of them. (b) The remaining three patients showed a normal Ig synthesis after stimulation with PWM and a slightly depressed IgM synthesis in response to S. aureus. They expressed a normal T helper cell function and did not show increased spontaneous suppressor T cell activity. They had low levels of natural killer cytotoxicity and the OKT4+/OKT8+ ratio was not significantly altered. Taken together, our data indicate that significant alterations of the in vitro immune response can be found in peripheral blood mononuclear cells of some immunoproliferative small intestinal disease patients after long term remission.

[Effect of a diet with an elevated protein quota on the immune status in the malabsorption syndrome]

The immune status was examined in 126 patients with malabsorption. Of these, 100 subjects suffered from chronic enteritis of varying severity. Twenty-six patients developed malabsorption after extensive resection of the small intestine. Lymphocyte proliferation and migration of peripheral blood leukocytes exposed to PHA served as immunologic criteria. The secondary immunodeficient status ascertained by the authors correlated with the disease severity and stage. The diets differing in the protein quota (100, 130, 160 g) were applied as the basic therapeutic factor. The best effect was attained with the diet containing 130 g protein which makes it possible to use it for immunocorrection in secondary immunodeficient states of varying etiology.

Combined cow's milk protein and gluten-induced enteropathy: common or rare?

A child is reported with unequivocal gluten and cow's milk protein-induced enteropathy. This is believed to be the first reported case of this association.