Wearable textile based on silver plated knitted sensor for respiratory rate monitoring.

Wearable systems are gaining broad acceptance for monitoring physiological parameters in several medical applications. Among a number of approaches, smart textiles have attracted interest because they are comfortable and do not impair patients' movements. In this article, we aim at developing a smart textile for respiratory monitoring based on a piezoresistive sensing element. Firstly, the calibration curve of the system and its hysteresis have been investigated. Then, the proposed system has been assessed on 6 healthy subjects. The volunteers were invited to wear the system to monitor their breathing rate. The results of the calibration show a good mean sensitivity (i.e., approximately 0.11V·%-1); although the hysteresis is not negligible, the system can follow the cycles also at high rates (up to 36 cycle·min-1). The feasibility assessment on 6 volunteers (two trials for each one) shows that the proposed system can estimate with good accuracy the breathing rate. Indeed, the results obtained by the proposed system were compared with the ones collected with a spirometer, used as reference. Considering all the experiments, a mean percentage error was approximately 2%. In conclusion, the proposed system has several valuable features (e.g., the sensing element is lightweight, the sensitivity is high, and it is possible to develop comfortable smart textile); in addition, the promising performances considering both metrological properties and assessment on volunteers foster future tests focused on: i) the possibility of developing and system embedding several sensing elements, and ii) to develop a wireless acquisition system, to allow comfortable and long-term acquisition in both patients and during sport activities.

Coeliac disease hidden by cryptogenic hypertransaminasaemia.

BACKGROUND: Hypertransaminasaemia of unknown, cryptogenic, origin occasionally has been found to be the only sign of coeliac disease. Raised concentrations of transaminases, or aminotransferases, have been retrospectively observed in about a half of patients with coeliac disease who are on a gluten-containing diet. We aimed to establish the overall prevalence of coeliac disease among patients with cryptogenic hypertransaminasaemia. METHODS: Of the 600 consecutive patients referred to our outpatient clinic for liver disease due to raised serum transaminases from September, 1995, to June, 1997, 55 were classified as having cryptogenic hypertransaminasaemia after the exclusion of every known cause of liver disease. These patients were tested by indirect immunofluorescence for IgA to endomysium and for IgA and IgG to gliadin. FINDINGS: Five patients were positive for both IgA to endomysium and IgG to gliadin, whereas IgA to gliadin was only found in four patients. IgG to gliadin was also present in another patient who was not positive for antibodies to endomysium. The six antibody-positive patients had duodenal biopsy that showed a subtotal villous atrophy consistent with coeliac disease in the five patients with antibodies to endomysium. The patient with only IgG to gliadin had a normal small-intestine mucosa. None of the five patients with coeliac disease had gastrointestinal symptoms. Liver biopsy samples were taken from three of the five patients with flat mucosa and showed a histological picture of nonspecific reactive hepatitis. Transaminase concentrations reverted to normal within 6 months in four patients with coeliac disease who followed a strict gluten-free diet. INTERPRETATION: Our results show that about 9% of patients with cryptogenic hypertransaminasaemia are affected by symptom-free coeliac disease. Gluten-sensitive enteropathy and antibody screening for coeliac disease by means of antibodies to endomysium and gliadin should be considered in these patients.

Frequency and significance of anti-gliadin and anti-endomysial antibodies in autoimmune hepatitis.

Celiac disease has been associated with autoimmune disorders, but its frequency in autoimmune hepatitis is unknown. Sera from 157 patients with type 1 autoimmune hepatitis, 24 patients with type 2 autoimmune hepatitis, 62 patients with primary biliary cirrhosis, 30 patients with chronic hepatitis B, and 80 patients with chronic hepatitis C were tested for immunoglobulin A anti-endomysial antibodies by indirect immunofluorescence and immunoglobulin A and G antibodies to gliadin by enzyme immunoassay. Duodenal biopsy evaluation was recommended in patients seropositive for immunoglobulin A anti-endomysial antibodies. Immunoglobulin A anti-endomysial antibodies were present in eight of the 181 patients with autoimmune hepatitis (4%), including six with type 1 disease (4%) and two with type 2 disease (8%). Immunoglobulin A antibodies to gliadin were found in six of these eight patients, but they were also present in two others, including one patient with chronic hepatitis C. Five of the eight patients with immunoglobulin A antiendomysial antibodies, including three patients with no gastrointestinal symptoms, had duodenal biopsies and subtotal villous atrophy was present in all of them. No patient with primary biliary cirrhosis or chronic viral hepatitis had antiendomysial antibodies. The presence of celiac disease in autoimmune hepatitis is high (at least one in 36 patients) and it is predominantly asymptomatic. Screening with anti-endomysial and anti-gliadin antibodies should be performed and results confirmed with intestinal biopsy.

Organ-specific autoantibodies in coeliac disease: do they represent an epiphenomenon or the expression of associated autoimmune disorders?

BACKGROUND AND AIMS: The occurrence of autoimmune disorders and organ-specific autoantibodies has been reported in coeliac disease. We assessed the prevalence of organ-specific autoantibodies in coeliac patients and evaluated whether their finding is an expression of associated autoimmune diseases. METHODS: Sera from 70 coeliac disease patients were tested for thyroid microsomal, gastric parietal cell, adrenal cortex and pancreatic islet cell antibodies by indirect immunofluorescence on O blood group human tissues. RESULTS: Eighteen coeliacs (26%) were positive for at least one of the autoantibodies studied; thyroid microsomal antibodies showed a higher prevalence (21%) than parietal cell (11%), adrenal cortex (4%) and islet cell antibodies (3%). In 15 (21%) of the 70 coeliacs studied an association with autoimmune diseases was found, including insulin dependent diabetes mellitus (6 cases), autoimmune hepatitis (3 cases), hypothyroidism (4 cases), thyrotoxicosis (1 case) and dermatomyositis (1 case). One or more organ-specific autoantibodies were positive in 12 (80%) of the 15 coeliacs with autoimmune disorders in comparison with their positivity in 6 (11%) of the 55 coeliacs without autoimmune diseases (p < 0.0001). CONCLUSIONS: The finding of organ-specific autoantibodies in coeliac patients discloses the coexistence of a wide spectrum of immunological diseases.

Human umbilical cord as substrate for IgA antiendomysial antibodies allows large scale screening for celiac sprue.

Sera from 800 patients referred to our laboratory for celiac sprue screening were tested for IgA antiendomysial antibodies on human umbilical cord (HUC-EmA) and for IgA and IgG antigliadin antibodies (AGA) on rodent tissue by indirect immunofluorescence. Thirty-three patients (4.1%) were positive for at least one of the two antibodies; IgA HUC-EmA were found in 25 patients, whereas IgA and IgG AGA were detected in 19 and 24 subjects, respectively. Twenty-seven (82%) of the 33 patients with immunological markers showed sub-total or severe partial villous atrophy consistent with celiac sprue, whereas the remaining six cases had normal histological findings. None of 30 antibody-negative biopsied patients showed abnormalities of duodenal mucosa. Of the 27 newly diagnosed celiacs, only 21 (78%) were positive for IgA and/or IgG AGA, whereas IgA HUC-EmA were found in all but two cases (93%). In these two cases, positive only for IgG AGA, celiac sprue was associated with IgA deficiency. Our study proves that the routine use of IgA HUC-EmA increases celiac sprue findings by up to 15% when compared with AGA.

IgA anti-endomysial antibodies on human umbilical cord tissue for celiac disease screening. Save both money and monkeys.

Since celiac disease screening by traditional IgA anti-endomysial antibody test is limited by high costs of monkey esophagus commercial kits as well as by rising ethical problems related to the endangered species, the identification of an inexpensive and commonly available substrate for this antibody determination is urgently required. To achieve this goal, we compared the prevalence of IgA anti-endomysial antibodies detected on monkey esophagus with that on human umbilical cord. Fifty-seven (95%) of 60 untreated adult celiacs were positive for these antibodies on monkey esophagus as well as on human umbilical cord. IgA anti-endomysial antibodies, detected on both tissues, were negative in all 200 disease and healthy controls tested, displaying a 100% specificity for gluten-sensitive enteropathy. These data suggest that human umbilical cord can replace monkey esophagus for IgA anti-endomysial antibodies test. Human umbilical cord allows unlimited testing for celiac disease screening on wide series of high-risk subjects, permitting identification of greater numbers of asymptomatic celiac patients with a remarkable saving of money and bypassing the ethical problems related to killing monkeys.

IFL- and ELISA-antigliadin antibodies recognize different antigenic reactivities from those of R1-antireticulin and antiendomysial antibodies.

In order to establish whether antigliadin antibodies, detected by indirect immunofluorescence (IFL-AGA), display the same antibody reactivity as ELISA-AGA or whether they cross-react with reticulin antibodies (R1-ARA and antiendomysial--EmA), sera from 16 untreated coeliac patients were repeatedly absorbed with crude gliadin dissolved in ethanol/water solution. The comparison between antibody activities before and after absorption demonstrated that IFL-AGA and ELISA-AGA are nothing but a single antibody, as both of them completely disappeared or markedly reduced their titre after incubation with crude gliadin. Moreover, AGA reactivity differs from the reactivity of antibodies directed against reticulin, as R1-ARA and EmA titres were not affected by crude gliadin absorption. The absolute absence of cross-reactivity between IFL-AGA and R1-ARA is further confirmed by the removal of the former and persistence of the latter after gliadin absorption in the 9 sera positive for both antibodies. Sera of coeliac patients, therefore, show only two discrete antibody reactivities, one directed to gliadin and the other to reticulin components.

Specific reactivity of fluorescein isothiocyanate-conjugated separated IgG and IgA from celiac disease sera on human tissues.

Study of the reaction of celiac disease-related antibodies with human substrates has been hampered by the immunological cross-reactivity between fluorescein isothiocyanate-conjugated anti-human immunoglobulins and immunoglobulins normally present in human tissues. In order to overcome this problem we extracted IgG from 2 celiac disease sera (positive for specific IgG and IgA antibodies) using a genetically engineered recombinant form of streptococcal protein G covalently immobilized on 4% agarose beads. The separated IgG and IgA was conjugated with fluorescein isothiocyanate and used in direct immunofluorescence on 0 blood group human duodenum, liver, and myocardium. Staining of the lamina propria beneath the villous epithelium, the endomysium of smooth muscle layers in the duodenum, and the liver sinusoidal and pericellular myocardial matrix was observed. The reactivity of celiac disease-related antibodies with various human tissues indicates that these antibodies are the result of a systemic immune response directed against all tissues containing matrix proteins.

IgA antibodies to jejunum. Specific immunity directed against target organ of gluten-sensitive enteropathy.

Serum IgA antibodies to jejunum (JAB) were found in 78 (96%) of 81 adults and children with untreated celiac disease. Not only did IgA JAB display a significant higher prevalence than IgA antigliadin antibodies (AGA) (72%) in untreated gluten-sensitive enteropathy, but they also allowed us to identify another three celiacs in addition to those detected by IgA antiendomysial antibodies (EmA). Like IgA EmA, IgA JAB persisted at low titer in seven (14%) of 50 celiacs tested after 12 months of gluten-free diet (GFD) despite the regrowth of jejunal villi, whereas IgA AGA disappeared in all these patients consistently with the normalization of intestinal mucosa. IgA JAB and EmA reappearance was close to 100% in the 13 celiacs studied after six months of gluten challenge, while IgA AGA reached the highest prevalence (about 70%) after one month of gluten ingestion without any increase in the following months. All disease and healthy controls were always negative for the three IgA antibodies. Our results prove that IgA JAB and EmA are the best screening tests for active (untreated and on gluten challenge) celiac disease, whereas IgA AGA should be used for monitoring the response to gluten withdrawal. IgA JAB are an expression of a specific immunity directed against the target organ of gluten-sensitive enteropathy, but, before ascribing them a role in the pathogenesis of celiac disease, it should be ascertained whether their production is a primary event leading to jejunal lesions or whether it is a secondary phenomenon due to antigen release from a previously damaged jejunal mucosa.

Increased serum IgA levels in subjects with previous myocardial infarction or other major ischemic events.

To ascertain whether the increase in serum IgA, which has been found to be associated with the presence of severe atherosclerotic disease, precedes or follows the occurrence of major ischemic events (MIE), we studied the serum levels of IgA as well as IgG and IgM in 145 subjects with acute or previous ischemic events and 34 controls. The subjects with previous myocardial infarction had higher IgA levels with respect to the controls, the patients with angina pectoris and those with acute myocardial infarction, while no significant differences concerning IgG and IgM were found. In the subjects with previous extracoronary events, immunoglobulin levels tended to be even higher. Overall, 30% of the subjects with previous MIE and only 3% of the controls had IgA levels over 4.5 g/l (p = 0.0018). This study indicates that total serum IgA is a marker of previous major ischemic events (protracted immune response to denatured proteins?), rather than a factor predisposing to atherosclerosis development.

Correlation between IgA antiendomysial antibodies and subtotal villous atrophy in dermatitis herpetiformis.

Serum IgA antiendomysial antibodies (EmA) were present in 20 (64.5%) of 31 patients with dermatitis herpetiformis (DH) on a normal diet. A significant correlation was found between these antibodies and the severity of gluten-induced jejunum damage. IgA EmA were positive in 19 (86%) of the 22 DH patients with subtotal villous atrophy, in comparison with the positivity of only one (11%) of the nine DH patients with less severe intestinal involvement (partial villous atrophy or mild abnormalities). The specificity of this test for gluten-sensitive enteropathy was 100%, these antibodies being consistently negative in biopsied disease controls showing a normal jejunal mucosa. Moreover, IgA EmA proved to be useful in monitoring the response to gluten withdrawal in DH patients, as these antibodies always disappeared in all the DH cases studied after 1 year of gluten-free diet together with the regrowth of jejunal villi. The strict relationship between IgA EmA and subtotal villous atrophy is more helpful still since the enteropathy present in DH is usually symptomless and therefore difficult to suspect.

IgA antiendomysial antibody test. A step forward in celiac disease screening.

Serum IgA antiendomysial antibodies (EmA) were found in 61 (87%) of 70 adults and children with untreated celiac disease, whereas IgA antigliadin antibodies (AGA) and IgA R1-antireticulin antibodies (R1-ARA) were positive in 71% and 47%, respectively, of the same patients. Two of the nine untreated celiacs negative for IgA EmA showed positivity for IgA AGA. While IgA AGA and R1-ARA disappeared in all the celiacs tested one year after gluten-free diet, IgA EmA persisted at low titer in seven (18%) of these 38 subjects, although the jejunal biopsy showed a complete regrowth of jejunal villi. All the disease control patients as well as the blood donors tested were always negative for the three IgA antibodies. Our results state that the search for both IgA EmA and AGA gives the best results in the screening of celiac disease, since the positivity for at least one of these two antibodies allows identification with a 100% specificity of the 90% of untreated celiac patients.

IgA subclass antibodies to gliadin in serum and intestinal juice of patients with coeliac disease.

Serum IgA anti-gliadin antibodies (AGA) were positive in 25 (68%) of 37 untreated adults with coeliac disease belonging mostly to IgA1 subclass (88%) and only in a few cases to IgA2 (12%). Antisecretory component IgA AGA were present in serum of seven patients (28%) by immunofluorescence and in nine (36%) by ELISA. The search for IgA AGA in jejunal juice of eight untreated children with coeliac disease was positive in seven cases (88%), with consistent finding of antisecretory component IgA AGA. These antibodies belonged with equal proportion to IgA1 and IgA2 subclasses. This study shows that in intestinal secretions of untreated coeliac disease cases the IgA immune response to gliadin is confined to polymeric anti-secretory component IgA with the same prevalence of IgA1 and IgA2 subclasses, while in serum IgA AGA are largely monomeric, more frequently of IgA1 than of IgA2 subclass, and with a lower proportion of polymeric anti-secretory component IgA (20-36%). The finding of secretory IgA AGA in serum of patients with coeliac disease could result from a spill-over from the intestinal mucosal synthesis into the circulation.

[Class IgA antigliadin antibodies and monitoring of compliance to gluten-free diet in celiac disease]. / Anticorpi antigliadina di classe IgA e monitoraggio della compliance alla dieta aglutinata nella malattia celiaca.

Antibodies to gliadin (AGA), detected by ELISA, were found in the sera of 37 (88%) of 42 patients with untreated adult celiac disease. IgG class AGA showed a higher sensitivity for the diagnosis of celiac disease than IgA AGA, but, while IgA AGA had a specificity of 100% for celiac disease, false positives of IgG class were present in 19% of 37 patients with ulcerative colitis and in 27% of 26 patients with Crohn's disease. Twenty-eight out of our 42 adult celiac patients were tested after 6-12 months of gluten free diet: IgG AGA persisted in 43% of them showing antibody titres lower than those observed in untreated celiac disease. IgA AGA became negative after gluten withdrawal and there was regrowth of jejunal villi in all but 2 adult celiac patients (7%), who continued to present IgA AGA positivity and subtotal villous atrophy. These 2 patients did not comply to the gluten free diet. Our study confirms the specificity of IgA AGA for untreated celiac disease and emphasizes their usefulness in monitoring the compliance with gluten free diet in adult celiac disease.

IgA antigliadin antibodies and persistence of jejunal lesions in adult coeliac disease.

In 46 adult patients with coeliac disease, 41 (89%) of whom were positive for IgA and/or IgG antigliadin antibodies (AGA) when untreated, we investigated after a gluten-free diet the relationship between the persistence of AGA, the persistence of jejunal lesions, and the duration and compliance with the diet. IgG AGA were positive in 21 coeliac patients (46%) after variable periods of gluten-free diet and were associated with IgA positivity only in 4 cases (9%). Both IgA and IgG AGA positivity appeared to be more related to the lack of improvement of the jejunal lesions than to the strictness and duration of gluten withdrawal. Nine coeliacs showed no improvement of jejunal lesions after the gluten-free diet. Of these 9, 4 showed persistent IgA AGA, while the remaining 5 resulted IgAAGA-negative as before when untreated. Though intestinal biopsy remains the best means of determining the positive effect of gluten withdrawal, the persistence of IgA AGA in treated coeliacs is always predictive of the persistence of severe jejunal lesions. The persistence of IgG AGA, on the contrary, should be regarded as an immunological memory.