Anti-epithelial Cell Antibodies Research Articles

Autoimmune enteropathy with a CD8+ CD7-T-cell small bowel intraepithelial lymphocytosis: case report and literature review

BackgroundAdult onset autoimmune enteropathy (AIE) is a rare condition characterized by diarrhea refractory to dietary therapy diagnosed in patients with evidence of autoimmune conditions. Auto-antibodies to gut epithelial cells and other tissues are commonly demonstrated. Despite increasing awareness, the pathogenesis, histologic, immunologic and clinical features of AIE remain uncertain. There remains controversy regarding the diagnostic criteria, the frequency and types of auto-antibodies and associated autoimmune conditions, and the extent and types of histologic and immunologic abnormalities. CD4+ T-cells are thought to at least responsible for this condition; whether other cell types, including B- and other T-cell subsets are involved, are uncertain. We present a unique case of AIE associated with a CD8+CD7- lymphocytosis and review the literature to characterize the histologic and immunologic abnormalities, and the autoantibodies and autoimmune conditions associated with AIE.Case PresentationWe present a case of immune mediated enteropathy distinguished by the CD8+CD7- intra-epithelial and lamina propria lymphocytosis. Twenty-nine cases of AIE have been reported. The majority of patients had auto-antibodies (typically anti-enterocyte), preferential small bowel involvement, and predominately CD3+ CD4+ infiltrates. Common therapies included steroids or immuno-suppressive agents and clinical response with associated with histologic improvement.ConclusionsAIE is most often characterized (1) IgG subclass anti-epithelial cell antibodies, (2) preferential small bowel involvement, and (3) CD3+ alphabeta TCR+ infiltrates; there is insufficient evidence to conclude CD4+ T-cells are solely responsible in all cases of AIE.

De novo development of circulating anti-endothelial cell antibodies rather than pre-existing antibodies is associated with post-transplant allograft rejection

Anti-endothelial cell antibodies (AECAs) are thought to be involved in the development of renal allograft rejection. To explore this further, we determine whether AECAs play a role both in predicting the incidence of allograft rejection and long-term outcomes by analysis of serum samples from 226 renal allograft recipients for AECAs pre- and post-transplant. Surprisingly, the presence of pre-existing AECAs was not associated with either an increased risk of rejection or a detrimental impact on recipient/graft survival. Subsequent de novo AECAs, however, were associated with a significantly increased risk of early acute rejection. Moreover, these rejections tended to be more severe with a significantly increased incidence of both steroid-resistant and multiple episodes of acute rejection. The acute rejections associated with de novo AECAs did not correlate with C4d deposition at the time of renal biopsy, but did demonstrate an association with the presence of glomerulitis and peritubular capillary inflammation. Significantly more patients with de novo AECAs developed graft dysfunction. Thus, our prospective study suggests the emergence of de novo AECAs is associated with transplant rejection that may lead to allograft dysfunction.

Micrometastasis to lymph nodes in stage I left lung cancer patients

Background. To evaluate the frequency and clinicopathological characteristics of lymph node micrometastasis in left lung cancer patients diagnosed to be stage IA and IB based on routine histopathologic examinations, we examined the lymph nodes in patients who had undergone an extended mediastinal lymphadenectomy, using immunohistochemical methods. Methods. Paraffin-embedded tissue sections from the lymph nodes in 49 patients with stage I left lung cancers were studied. We used AE1/AE3 as the anticytokeratin and Ber-EP4 as the antiepithelial cell antibodies when performing immunohistochemical staining. Results. We identified micrometastasis of the lymph nodes in 13 (26.5%) of 49 patients with stage I left lung cancer. N0 disease was reclassified as N1 disease in 5 cases, N2 disease in 6 cases, and N3 disease in 2 cases. The location of the micrometastatic lymph nodes proved to be wide regions including the contralateral and highest mediastinal nodes, and 6 (46.2%) out of the 13 patients with micrometastasis were thus presumed not to be completely eliminated by a standard lymphadenectomy through an ipsilateral thoracotomy. The five year survival rate of patients with reclassified N1 to N3 disease was 74%, and the presence of micrometastasis was found to have no significant effect on the outcomes. Conclusions. The micrometastatic involvement of the lymph nodes was both more frequent and extensive than expected even in stage I left lung cancer. These results suggest that an extended mediastinal lymphadenectomy may therefore be required for the locoregional control of stage I left lung cancer patients.

The role of anti-epithelial cell antibodies in the pathogenesis of bilateral radiation pneumonitis caused by unilateral thoracic irradiation

Two cases of bilateral radiation pneumonitis associated with unilateral thoracic irradiation against lung cancer are described. Both patients died of respiratory failure and autopsy was performed. Histologically, bilateral diffuse alveolar damage was demonstrated in both cases, associated with marked organization of hyaline membrane in one case (case 1). In addition, numerous hyperplastic type II pneumocytes which strongly expressed cytokeratins 8, 18 and 19 were observed. In both patients' sera, antibodies against cytokeratin 8, 18 and 19 were demonstrated by a Western immunoblot. The possible association between autoantibodies to cytokeratins and diffuse alveolar damage observed in patients with bilateral radiation pneumonitis are discussed.

Immunology of inflammatory bowel disease

The past year has seen continued expansion of the understanding of immune events in inflammatory bowel disease (IBD). New insights have been gained into how macrophages, T cells, and B cells gain access to the mucosal immune compartment. The role of cytokines, particularly cytokines from subsets of T-helper cells, were further characterized. It appears that cytokines characteristic of T-helper type 1 cells likely play a role in the pathologic inflammation of IBD. Responses to cytokines, as well as cytokine production, may also be abnormal in IBD. The potential targets and site of production of antineutrophil cytoplasmic antibodies have been characterized. Antiepithelial cell antibodies were investigated as well. A number of animal models of IBD appeared or were further studied in the past year. Thus, accumulating understanding suggests that disruption of certain key regulatory mechanisms may result in pathologic immune responses to luminal bacteria, resulting in chronic inflammation

Antiepithelial cell antibodies do not impair paediatric renal allograft survival but appear to be associated with acute viral infections

There is a reported association between antiepithelial cell (AEC) antibodies and increased renal allograft loss in paediatric recipients. Our unit experienced a dramatic fall in 1-year graft survival so we undertook a study to determine if AEC antibodies could account for such losses. We also studied healthy children and adults as well as a group of individuals with serologically proven viral infection in an attempt to determine the prevalence and possible aetiology of these antibodies. Sera were screened for AEC antibodies in a microcytotoxicity test using a lung epithelial cell line (A549) as target. The prevalence of these antibodies in our paediatric recipients was similar to that reported elsewhere but we found no correlation between the presence of AEC antibody and allograft loss. Within the control populations, we found the antibody was more prevalent in children than in adults ( p < 0.0001). We also found a strong age banding pattern, with antibody being present in 50% of children under 10 years and declining with increasing age, so that by the age of 16 years the seroprevalence was similar to that found in our adults. However, AEC antibody had a significantly higher prevalence in individual with active viral infection than in our healthy control group ( p = 0.00003). A positive association was noted between rubella and respiratory syncytial virus and AEC antibody presence and a negative association with varicella zoster. We conclude that AEC antibodies do not correlate with increased paediatric renal allograft loss but appear to be linked to certain viral infections.

Anti-epithelial (anti-A549) antibodies: their nature, specificity and relevance to transplantation

Several studies have addressed the possible importance of anti-epithelial cell antibodies in kidney transplantation using the A549 cell line as an in vitro model. In this paper we report our results using for the first time an enzyme-linked immunosorbent assay (ELISA) to detect the anti-A549 cell antibodies. Sera from 129 kidney transplant patients were tested for IgM anti-epithelial cell antibodies directed against the A549 cell line prior to transplantation; only three sera were positive (2.3%). 101 of these patients were then followed-up post-transplantation; sera were collected routinely at 2, 6 and 12 weeks and at the time of rejection episodes. All samples were also tested for cytomegalovirus (CMV) IgM antibodies. Sixteen patients developed anti-A549 IgM antibodies, and there was no correlation with acute graft rejection. Anti-epithelial antibodies showed no binding to sections of normal kidney or biopsies of rejected kidneys. Elevent patients were positive for anti-CMV IgM antibodies. In nine cases both IgM anti-A549 and IgM anti-CMV antibodies were found, which was a highly significant association ( p < 0.001). Analysis of A549 cellular proteins by immunoblotting gave evidence for the presence of CMV polypeptides in the cell lysate. Electron-microscopic examination of A549 cell preparations revealed intracellular particles which were compatible in size with CMV. Polymerase chain reaction analysis confirmed the presence of a specific CMV DNA sequence in A549 cells of several batches from different sources. Our data strongly suggest that the A549 cell line used in several published reports is infected with CMV and that in the majority of cases the anti-A549 ‘anti-epithelial’ antibodies found in renal transplant patients are anti-CMV antibodies.

Pre-transplant anti-epithelial cell antibodies and graft failure after single lung transplantation

Eighty-five patients undergoing single lung transplantation have been studied to determine the presence of anti-epithelial cell antibodies (AECA) prior to transplantation using the human lung carcinoma epithelial cell line A549 in a microcytotoxicity assay. In addition, 29 healthy volunteers were also assayed for the presence of AECA. Twenty-seven of the 85 recipients exhibited AECA prior to transplantation compared to none of the 29 control subjects ( p = 0.0001). Actuarial graft survival at 1 year was 78% for the AECA negative group compared to 56% for AECA positive recipients ( p = 0.01). No correlation was seen between the presence of AECA and graft rejection as determined by transbronchial biopsy. However, there was an association between AECA and post-transplant infection ( p = NS) where 16 (64%) of the AECA positive recipients had postoperative infection episodes compared to 25 (47%) of the negative recipients. Sodium dodecylsulphate polyacrylamide gel electrophoresis and Western blotting was also performed for 68 of the recipients and antibody reactivity was detected in 22 patients compared to 26 patients exhibiting AECA detectable by microcytotoxicity. The presence of AECA demonstrable by Western blotting did not correlate with graft survival, rejection or infection. In conclusion, AECA detectable prior to single lung transplantation are associated with a decrease in graft survival and with postoperative infections.

Autoantibody prevalence and association in inflammatory bowel disease

Objective: To study the prevalence and correlation of the following antibodies with disease activity: antineutrophil cytoplasmic antibodies (ANCA), anti-endothelial cell antibodies (AECA) and anti-epithelial cell (anti-EPI) antibodies. Patients and methods: Sera from the following patients were tested: 41 patients with ulcerative colitis, 30 patients with ulcerative colitis following restorative proctocolectomy (RPC), 30 patients with Crohn's disease, 10 disease controls, and 34 healthy controls. Results: ANCA were found in 65 patients (64%) [31 with ulcerative colitis (76%); 21 with ulcerative colitis following RPC (70%); 13 with Crohn's disease (43%)]

Presence of anti-basal cell antibodies in oral lichen planus

An autoimmune hypothesis for oral lichen planus (OLP) has been proposed, but no anti-basal cell antibodies (anti-BCA) have been found in the sera of patients with OLP. Our purpose was to test whether the negative results of anti-BCA assays in sera have been due to the insensitivity of the substrates. Rat esophagus, monkey esophagus, as well as human oral mucosa and skin were used to detect anti-BCA in sera of OLP patients. By indirect immunofluorescence technique, the rat esophagus was found to be the most sensitive substrate. Therefore it was used as the only substrate to test the presence of anti-epithelial cell antibodies (anti-ECA) in a large group of patients with OLP and other oral mucosal diseases or normal control subjects. The results showed that anti-ECA were detected in 54% (34 of 63) of patients with OLP, 71% (15 of 21) of patients with aphthous ulcers, 29% (6 of 21) of patients with oral carcinoma, 20% (2 of 10) of patients with traumatic ulcer, and 7% (1 of 15) of patients with periodontitis but none of the healthy control subjects (n = 41). The presence of anti-BCA in OLP patients' sera was persistent and lasted for a few months or years. There was a decrease in the serum anti-BCA titers in six of eight anti-BCA-positive OLP patients after topical application of triamcinolone. These anti-BCA that persist longer in OLP patients' sera may be autoantibodies that are raised against altered basal cell-specific antigens.

Autoimmune enteropathy and nephropathy with circulating anti-epithelial cell antibodies

We describe a child with circulating anti-epithelial cell antibodies, autoimmune enteropathy with intestinal villous atrophy, and membranous glomerulonephritis. The patient had persistent diarrhea at 6 months of age, and a small bowel biopsy showed active enteritis, villous atrophy, and crypt hyperplasia. When the patient was, 10 months of age, nephrotic syndrome developed because of membranous glomerulonephritis. Results of tests for circulating immune complexes were negative. Indirect immunofluorescence studies revealed a circulating antibody directed against renal epithelial cells. Circulating antibodies directed against normal small intestine epithelial cells were also detected by the immunoperoxidase technique. Western blot and immunoprecipitation identified a 55-kd antigen, in both small bowel and kidney, that reacted with an antibody in the patient's serum. High-dose prednisone therapy induced a clinical remission, resolution of the small bowel injury, and diminished serum anti-epithelial cell antibodies; after dose reduction, clinical relapse occurred with villous atrophy and reappearance of anti-epithelial cell antibodies. When the patient was 45 months of age, persistent diarrhea recurred despite intravenous administration of corticosteroids, cyclosporine, and total parenteral nutrition. Autoantibodies to a 55-kd epithelial cell protein are temporally related to the development of enteropathy and nephropathy. Study of similar patients is needed to determine the role of such antibodies in this disorder.

Autoreactivity and Altered Immune Responses in Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is a poorly understood condition that is associated with a wide variety of immunologic alterations. Because its pathogenesis is unknown, these immunologic alterations have been investigated with an eye toward unraveling the complex mechanism of injury in the bowels of these patients. There are several lines of evidence suggesting that IBD is related to immunologic events. The histopathology of active disease resembles the Arthus reaction, whereas the presence of antiepithelial cell antibodies is reminiscent of Goodpasture's disease. Antibodies against many microorganisms and autoantibodies to mucosal components are commonly found in these patients. Further, there is a marked increase in plasma cells in the lamina propria of patients with active IBD. It is important to keep these findings in perspective. No studies to date have been able to determine whether the features are entirely primary events, that is, related to the initial damage to the intestinal mucosa. If the surface mucosa is injured by an as-yet-unidentified agent, the immunologic findings in IBD may be secondary events. Nonetheless, the similarity in histopathology of the experimental immunologic models of IBD to the human disease encourages investigators to pursue the etiology of this complex disease.

Heterogeneity of the human thymus epithelial microenvironment at the ultrastructural level.

The supporting meshwork of the thymus, which is composed of epithelial cells (epithelial-reticular cells), plays a major role in the generation of immunocompetent T lymphocytes. From the characterization and location of lymphocytes in the thymus it can be hypothesized that different microenvironments exist promoting different steps in intrathymic T cell maturation. Our findings on heterogeneity of human thymus epithelial cells synthesizing various thymosin components1 and heterogeneity in antigen expression revealed by monoclonal anti-epithelial cell antibodies (this issue, p 297) gives support to this hypothesis. Also in electron microscopy, variation in ultrastructural characteristics of epithelial cells has been noted.2,3 We studied the ultrastructural morphology of epithelial cells in sections of the human thymus to evaluate whether interrelationships exist between epithelial cell subtypes and between morphology and function in the microenvironment.